A micro-diffusion swirl combustion device using hydrogen as fuel

Abstract

The present invention relates to the technical field of swirl combustion, and in particular to a micro-diffusion swirl combustion device using hydrogen as fuel. In the device, a first shell is provided with a hydrogen inlet, a first cavity is formed inside, and the hydrogen inlet is connected to the first cavity; a second shell is provided with an air inlet, a second cavity is formed inside, and the air inlet is connected to the second cavity; the top of the second shell is provided with an end plate for connecting to the combustion chamber, the end plate is provided with a plurality of air microchannels, and each of the air microchannels is a zoom structure; the bottom of a plurality of hydrogen pipelines is located at the top of the first shell, each of the hydrogen pipelines is passed through the second cavity and the air microchannel and exceeds the top surface of the end plate, and the hydrogen pipeline is connected to the first cavity. The above solution can solve the problems of unstable backfire, local overheating, and increased nitrogen oxide emissions.

Description

Technical Field

[0001] The invention relates to the technical field of swirl combustion, and in particular to a micro-diffusion swirl combustion device using hydrogen as fuel. Background Art

[0002] Hydrogen emits no carbon during combustion and can be used as a carbon-free alternative fuel for gas turbine combustion to generate electricity.

[0003] Hydrogen has extreme physical properties that can easily lead to problems in combustion devices, such as unstable flashback, local overheating, and increased nitrogen oxide emissions. Therefore, it is necessary to propose a micro-diffusion swirl combustion device using hydrogen as fuel to solve the above technical problems. Summary of the Invention

[0004] The embodiment of the present invention provides a micro-diffusion swirl combustion device using hydrogen as fuel, which can solve the problems of unstable backfire, local overheating, and increased nitrogen oxide emissions.

[0005] The embodiment of the present invention provides a micro-diffusion swirl combustion device using hydrogen as fuel, comprising:

[0006] The first shell is provided with a hydrogen inlet, and a first cavity is formed inside the first shell, wherein the hydrogen inlet is connected to the first cavity;

[0007] A second shell is provided with an air inlet, and a second cavity is formed inside. The air inlet is connected to the second cavity. An end plate for connecting to the combustion chamber is provided on the top of the second shell. The end plate is provided with a plurality of air microchannels, each of which is a zoom structure.

[0008] A plurality of hydrogen pipelines, the bottom of which is located at the top of the first shell, each of the hydrogen pipelines is arranged through the second cavity and the air microchannel and exceeds the top surface of the end plate, and the hydrogen pipeline is connected to the first cavity.

[0009] The present invention provides a micro-diffusion swirl combustion device fueled by hydrogen. By configuring each air microchannel with a zooming structure, this enhances the outward diffusion of air, creating a low-pressure zone at the top of multiple hydrogen pipes. This allows for more uniform mixing of hydrogen and air at the nozzle outlet, forming a microscale wind-enclosed flame structure that balances low NOx emissions, uniform temperature distribution, and flame independence. This technical solution can therefore address issues such as unstable backfire, localized overheating, and elevated nitrogen oxide emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0011] Figure 1 A schematic structural diagram of a micro-diffusion swirl combustion device using hydrogen as fuel provided by one embodiment of the present invention;

[0012] Figure 2 for Figure 1 A top view of the composite combustion device shown;

[0013] Figure 3 for Figure 1 A bottom view of the composite combustion device shown;

[0014] Figure 4 for Figure 1 AA cross-sectional schematic diagram of the composite combustion device shown;

[0015] Figure 5 for Figure 1 BB cross-sectional schematic diagram of the composite combustion device shown;

[0016] Figure 6 for Figure 5 An enlarged schematic diagram of point C of the composite combustion device is shown.

[0017] Reference numerals:

[0018] 1- first shell;

[0019] 11- Hydrogen inlet;

[0020] 12-first cavity;

[0021] 13- support column;

[0022] 14-Hydrogen deflector;

[0023] 2- second shell;

[0024] 21- air inlet;

[0025] 22- second cavity;

[0026] 23-end plate;

[0027] 24-air microchannel;

[0028] 25-air deflector;

[0029] 3- Hydrogen pipeline;

[0030] 31-Threaded structure. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions 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 part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] like Figures 1 to 6 As shown, an embodiment of the present invention provides a micro-diffusion swirl combustion device using hydrogen as fuel, the device comprising:

[0033] The first shell 1 is provided with a hydrogen inlet 11 and forms a first cavity 12 inside, and the hydrogen inlet 11 is connected to the first cavity 12;

[0034] The second shell 2 is provided with an air inlet 21 and a second cavity 22 is formed inside. The air inlet 21 is connected to the second cavity 22. The top of the second shell 2 is provided with an end plate 23 for connecting to the combustion chamber. The end plate 23 is provided with a plurality of air microchannels 24, each of which is a zoom structure.

[0035] The bottom of the plurality of hydrogen pipelines 3 is located at the top of the first shell 1 . Each hydrogen pipeline 3 passes through the second cavity 22 and the air microchannel 24 and exceeds the top surface of the end plate 23 . The hydrogen pipeline 3 is connected to the first cavity 12 .

[0036] In this embodiment, by configuring each air microchannel 24 as a zooming structure, the outward diffusion of air is enhanced, creating a low-pressure zone at the top of the multiple hydrogen pipes 3. This allows for more uniform mixing of hydrogen and air at the nozzle outlet, forming a microscale air-enclosed flame structure that balances low NOx emissions, uniform temperature distribution, and flame independence. Therefore, this technical solution can address issues such as unstable backfire, localized overheating, and elevated nitrogen oxide emissions.

[0037] In some embodiments, the swirl combustion device can be applied to a gas turbine and a gas boiler combustion chamber, which is not specifically limited herein.

[0038] In some embodiments, the height of the second cavity 22 is 1.43 times the height of the first cavity 12 , so that the air entering the second cavity 22 has more diffusion space in the axial direction and the air is evenly distributed in the second cavity 22 .

[0039] like Figure 5As shown, in one embodiment of the present invention, a support column 13 and a hydrogen guide plate 14 are provided in the first shell 1. The support column 13 is vertically arranged at the bottom of the first shell 1. The hydrogen guide plate 14 is a circular plate. The hydrogen inlet 11 is arranged at the bottom of the first shell 1. The hydrogen guide plate 14 is opposite to the hydrogen inlet 11 and is perpendicular to the hydrogen flow direction.

[0040] In this embodiment, when hydrogen enters the first cavity 12 from the hydrogen inlet 11, after contacting the hydrogen guide plate 14, it flows along the lower side of the hydrogen guide plate 14 to the edge, generating backflow in the first cavity 12, increasing the degree of chaos of the hydrogen flow, and thus making the hydrogen evenly distributed in the first cavity 12, ensuring that the hydrogen is evenly distributed in each hydrogen pipeline 3.

[0041] In some embodiments, the support columns 13 are three cylinders with a diameter of 8 mm and a height of 8 mm that are evenly arranged in a circle, and the hydrogen guide plate 14 is a circular baffle plate with a diameter of 100 mm and a thickness of 2 mm.

[0042] In one embodiment of the present invention, the air inlet 21 is disposed on the side of the second housing 2, and the length of the hydrogen conduit 3 is perpendicular to the air flow direction. This arrangement can increase the degree of disorder in the air flow, thereby evenly distributing the air in the second cavity 22.

[0043] In one embodiment of the present invention, an air deflector 25 is disposed within the second housing 2. The air deflector 25 is located at the bottom of the second housing 2 and is positioned around the periphery of the hydrogen pipeline 3. The air deflector 25 faces the air inlet 21 and is perpendicular to the air flow. Both the first housing 1 and the second housing 2 are cylindrical structures. The air deflector 25 is an arc-shaped plate. The multiple hydrogen pipelines 3 are arranged in a circular pattern, with the arc center of the air deflector 25 facing the hydrogen pipeline 3.

[0044] In this embodiment, the center of the air deflector 25 is opposite to the air inlet 21, so that the air is first blocked by the air deflector 25, and the air flows along the outer diameter surface of the air deflector 25 to the edge and then diffuses into the interior of the second cavity 22, and is further blocked by the multiple hydrogen pipelines 3, so that the air is further diffused in the second cavity 22, thereby further improving the uniformity of distribution.

[0045] In one embodiment of the present invention, there are 312 hydrogen pipelines 3, which are divided into twelve circles and arranged in a concentric circle array. The diameter difference between two adjacent concentric circles in the first ten circles from the center of the circle is the same. The diameter of the concentric circle in the eleventh circle is 0.15 times larger than the diameter of the concentric circle in the tenth circle. The diameter of the concentric circle in the twelfth circle is 0.35 times larger than the diameter of the concentric circle in the eleventh circle. There are 4n hydrogen pipelines 3 in each circle, where n is the number of circles.

[0046] Given that the combustion chamber is slightly larger than the outermost concentric circle of the burner, hydrogen and air ejected from the outermost nozzles may flow back into the low-pressure area where the airflow was ejected, leading to concentrated combustion. Therefore, this technical issue can be resolved by setting the diameter of the eleventh concentric circle to be 0.15 times larger than that of the tenth concentric circle, and the diameter of the twelfth concentric circle to be 0.35 times larger than that of the eleventh concentric circle.

[0047] For example, the diameters of the concentric circles are 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 115 mm, and 135 mm respectively. The number of pipes arranged in each layer from the inside to the outside is z=4n (1≤n≤12), that is, the number of pipes in each circle is 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, and 48 respectively.

[0048] In one embodiment of the present invention, each concentric circle extending outward from the center of the circle is deflected 10° clockwise from the previous concentric circle. This arrangement can further enhance the degree of swirl at the nozzle outlet, thereby ensuring more uniform mixing of hydrogen and air at the nozzle outlet.

[0049] For the flame tube, the recommended heat capacity intensity is 1234~2073kJ / (m 3 ·h·Pa), so the design heat capacity intensity is selected as 1519kJ / (m 3 ·h·Pa). To ensure that the heat capacity intensity of the combustion device is appropriate and uniform, the design power range of the combustion device is 100-300kW, the equivalence ratio range is 0.4-0.9, and the pressure range is 0.1-3MPa. To meet the heat capacity intensity requirements, the inner diameter of each hydrogen pipeline 3 in the first ten circles from the center outward is 0.8mm and the outer diameter is 1.2mm. The inner diameter of each hydrogen pipeline 3 in the eleventh circle is 1mm and the outer diameter is 1.5mm. The inner diameter of each hydrogen pipeline 3 in the twelfth circle is 1.5mm and the outer diameter is 2mm.

[0050] There are 312 air microchannels 24, each of which coincides with the center of a hydrogen pipeline 3. The inlet and outlet diameters of each air microchannel 24 in the first ten circles from the center of the circle are 3 mm, and the throat diameter is 2 mm. The inlet and outlet diameters of each air microchannel 24 in the eleventh circle are 3.2 mm, and the throat diameter is 2.2 mm. The inlet and outlet diameters of each air microchannel 24 in the twelfth circle are 3.4 mm, and the throat diameter is 2.4 mm.

[0051] In one embodiment of the present invention, the outer surface of the portion of each hydrogen pipeline 3 located within the air microchannel 24 is provided with a threaded structure 31. The threaded cross-section of the threaded structure 31 is an isosceles trapezoid with a short side length of 0.08 mm, a long side length of 0.22 mm, and a height of 0.12 mm. The hydrogen pipeline 3 extends 231 mm beyond the end plate. The angle between the threaded structure 31 and the horizontal plane is 60°. The hydrogen flow rate in the hydrogen pipeline 3 is between 40 and 70 m / s, and the applicable pressure is between 0.5 and 3 atm. This configuration allows air to conform to the hydrogen pipeline 3 in the contraction section of the zoom structure, moving along the submillimeter-scale threads of the swirl-guided flow on the pipe wall. After passing through the throat, the air can fully diffuse in the expansion section, forming an outward-diffusion swirl of air flow.

[0052] That is, the air is compressed when passing through the tapered section of the circular array of air microchannels 24, and has a tendency to converge toward the central axis, flowing close to the wall of the circular array of hydrogen pipes 3. The air near the center generates a swirl under the guidance of the swirl guide thread on the wall of the hydrogen pipe 3. The hydrogen branch (7) is still provided with threads on the outer wall of the portion corresponding to the gradually expanding section of the air microchannel 24. When the air enters the gradually expanding section, it diffuses outward while still having certain swirl characteristics, presenting a diffuse outward swirling flow state, so as to generate a low pressure area near the outer wall of the hydrogen pipe 3, so that the hydrogen and air are mixed more evenly at the nozzle outlet, forming a micro-scale wind-enclosed fire structure, taking into account the characteristics of low NOx emissions, uniform temperature field distribution and independent flame.

[0053] In some embodiments, the end plate 23 is a ring with an inner diameter of 162 mm and an outer diameter of 320 mm. Six circular holes with a diameter of 18 mm are evenly distributed on the ring in a circular trajectory with a diameter of 280 mm so as to be connected to the connecting plate on the combustion chamber side.

[0054] In summary, hydrogen plays a huge role in energy storage, chemical industry, aviation engines, gas turbines and other fields, and has become an effective way to reduce carbon emissions and mitigate the greenhouse effect. With the rapid development of new energy sources such as wind, light, and water in my country, a large amount of hydrogen is obtained through hydrogen production and storage systems, and combustion is one of the most effective and direct ways to utilize hydrogen. Compared with traditional hydrogen combustion devices, the micro-diffusion swirl combustion device provided by the above technical solution has the advantages of avoiding the risk of backfire, reducing the harm of nozzle ablation, and making the temperature distribution of the combustion field more uniform. It provides strong technical support and safety guarantees for hydrogen combustion devices in gas turbines and aviation engines.

[0055] Specifically, hydrogen is supplied to the burner using a hydrogen cylinder, and air is supplied to the burner via an oil-free air compressor. Hydrogen and air deflectors are used to evenly distribute the gas entering the burner, thereby evenly distributing the hydrogen / air throughout the circular array of hydrogen pipes and air microchannels. The gas is then sprayed into the combustion chamber via the hydrogen pipes and air microchannels, and ignited by a high-pressure, high-energy arc igniter for stable combustion. When changing combustion conditions, when increasing power, the air volume is first adjusted to reach the desired volume and achieve stable combustion, and then the hydrogen volume is adjusted to achieve the desired power. When decreasing power, the hydrogen volume is first reduced to reach the desired power and achieve stable combustion, and then the air volume is adjusted. When changing pressure, the hydrogen supply is first cut off, and then air is introduced or released into the sealed combustion chamber. When the pressure in the combustion chamber reaches the desired state, hydrogen is introduced and ignited, achieving safe hydrogen combustion. Compared with traditional hydrogen combustion devices, the hydrogen burner disclosed in the embodiment of the present invention has the advantages of avoiding the risk of backfire, reducing the harm of nozzle ablation, and making the temperature distribution of the combustion field more uniform. It provides strong technical support and safety guarantees for hydrogen combustion devices in gas turbines and aircraft engines.

[0056] It should be noted that, in this article, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the presence of other identical factors in the process, method, article or device comprising the elements.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A micro-diffusion swirl combustion device using hydrogen as fuel, characterized in that: include: A first shell (1) is provided with a hydrogen inlet (11), and a first cavity (12) is formed inside the shell, wherein the hydrogen inlet (11) is in communication with the first cavity (12); A second shell (2) is provided with an air inlet (21), and a second cavity (22) is formed inside the second shell (2), wherein the air inlet (21) is in communication with the second cavity (22), and an end plate (23) for connecting to the combustion chamber is provided on the top of the second shell (2), and the end plate (23) is provided with a plurality of air microchannels (24), and each of the air microchannels (24) is a zoom structure; a plurality of hydrogen pipelines (3), the bottom of which is located at the top of the first shell (1), each of the hydrogen pipelines (3) is arranged through the second cavity (22) and the air microchannel (24) and exceeds the top surface of the end plate (23), and the hydrogen pipeline (3) is in communication with the first cavity (12); A support column (13) and a hydrogen guide plate (14) are provided in the first shell (1), the support column (13) is vertically arranged at the bottom of the first shell (1), the hydrogen guide plate (14) is a circular plate, the hydrogen inlet (11) is arranged at the bottom of the first shell (1), the hydrogen guide plate (14) is directly opposite to the hydrogen inlet (11), and the hydrogen guide plate (14) is perpendicular to the hydrogen flow direction; An air deflector (25) is provided in the second shell (2), the air deflector (25) being provided at the bottom of the second shell (2), the air deflector (25) being located on the periphery of the hydrogen pipeline (3), the air deflector (25) being directly opposite to the air inlet (21), and the air deflector (25) being perpendicular to the air flow direction; The first shell (1) and the second shell (2) are both cylindrical structures, the air guide plate (25) is an arc-shaped plate, and the plurality of hydrogen pipelines (3) form a plurality of arranged circles, with the arc center of the air guide plate (25) facing the hydrogen pipeline (3); There are 312 hydrogen pipelines (3), and the 312 hydrogen pipelines (3) are divided into 12 circles and arranged in a concentric circle array. The diameter difference between two adjacent concentric circles in the first ten circles from the center of the circle is the same. The diameter of the concentric circle of the eleventh circle is 0.15 times larger than the diameter of the concentric circle of the tenth circle. The diameter of the concentric circle of the twelfth circle is 0.35 times larger than the diameter of the concentric circle of the eleventh circle. There are 4n hydrogen pipelines (3) in each circle, where n is the number of circles. Each concentric circle from the center outward is deflected 10° clockwise from the previous concentric circle; The outer surface of the portion of each hydrogen pipeline (3) located within the air microchannel (24) is provided with a thread structure (31).

2. The device according to claim 1, characterized in that The air inlet (21) is arranged on the side of the second shell (2), and the length direction of the hydrogen pipeline (3) is perpendicular to the air flow direction.

3. The device according to claim 1, characterized in that The inner diameter of each hydrogen pipeline (3) in the first ten circles from the center outward is 0.8 mm, and the outer diameter is 1.2 mm; the inner diameter of each hydrogen pipeline (3) in the eleventh circle is 1 mm, and the outer diameter is 1.5 mm; the inner diameter of each hydrogen pipeline (3) in the twelfth circle is 1.5 mm, and the outer diameter is 2 mm; There are 312 air microchannels (24), each of which coincides with the center of one hydrogen pipeline (3). The inlet and outlet diameters of each of the air microchannels (24) in the first ten circles from the center outward are 3 mm, and the throat diameter is 2 mm. The inlet and outlet diameters of each of the air microchannels (24) in the eleventh circle are 3.2 mm, and the throat diameter is 2.2 mm. The inlet and outlet diameters of each of the air microchannels (24) in the twelfth circle are 3.4 mm, and the throat diameter is 2.4 mm.

4. The device according to claim 1, characterized in that The thread cross-section of the thread structure (31) is an isosceles trapezoid with a short side length of 0.08 mm, a long side length of 0.22 mm, and a height of 0.12 mm. The hydrogen pipeline (3) extends beyond the end plate (23) by 1 mm. The angle between the thread angle of the thread structure (31) and the horizontal plane is 60°. The hydrogen flow rate in the hydrogen pipeline (3) is 40-70 m / s, and the applicable pressure is 0.5 atm-3 atm.

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