A concentric pure hydrogen combustion micro-mixing combustion chamber head

Abstract

The present invention relates to the technical field of gas turbine engines, and discloses a concentric pure hydrogen combustion micro-mixing combustion chamber head. By arranging a combustion bowl on the secondary hydrogen fuel nozzle, the secondary hydrogen fuel achieves stable hydrogen combustion in the low-operating condition central area downstream of the combustion bowl, and forms a stable low-speed central recirculation zone on the leeward side of the combustion bowl. The central recirculation zone ensures good secondary combustion stability. The main hydrogen fuel ejected from the inner ring radial injection holes and the outer ring radial injection holes are respectively micro-premixed with the incoming air, thereby improving the mixing quality and spatial distribution uniformity of the hydrogen fuel during the premixing process, thereby avoiding the problem of "backfire" in the main hydrogen fuel combustion; at the same time, a low-speed and relatively large-scale large-scale annular recirculation vortex structure is formed on the leeward side of the V-shaped ring, and stable combustion is carried out in the large annular recirculation vortex, thereby improving the stability and uniformity of the main hydrogen combustion and reducing NOx emissions.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbine engines and discloses a concentric circle pure hydrogen combustion micro-mixing combustion chamber head. Background Art

[0002] Hydrogen energy power is the most anticipated technical approach to aviation carbon neutrality. Its main technical advantages include: liquid hydrogen as fuel for gas turbine engines has an energy density (calorific value) that is 2.78 times that of traditional aviation kerosene; hydrogen does not produce carbon oxides and smoke during combustion, that is, the amount of carbon dioxide released by burning hydrogen is zero, and zero carbon emissions can be achieved; hydrogen fuel has high thermal stability and high heat sink, making it a more ideal cooling medium for aviation power and more conducive to engine thermal management.

[0003] Common hydrogen combustion methods in aircraft engine combustion chambers include premixed and non-premixed combustion. Premixed combustion involves premixing hydrogen and air within microchannels, with the mixture then ejected through the same nozzle as a single jet. Premixed combustion effectively reduces nitrogen oxide (NOx) emissions from hydrogen combustion. While generating the same amount of heat, NOx production from premixed hydrogen combustion can be reduced to 1 / 20th that of jet fuel. However, the reactivity and higher flame speed of hydrogen in the premixed reaction result in a thinner flame front and increased upstream flame migration, increasing the risk of flashback. Non-premixed combustion is a novel combustion method, also known as diffusion combustion. Hydrogen and air pass through the jet channel at high speeds, with hydrogen injected at the air outlet. The two gases then mix and burn at the microchannel outlet. Compared to premixed combustion, diffusion combustion avoids the "flashback" problem of hydrogen combustion, thereby improving combustion efficiency and stability. However, diffusion combustion is associated with higher NOx emissions.

[0004] Therefore, problems such as flashback and high NOx emissions in the existing technology still hinder the widespread application of hydrogen fueled gas turbine engines. Summary of the Invention

[0005] The purpose of the present invention is to provide a concentric pure hydrogen combustion micro-mixing combustion chamber head, which can effectively suppress the hydrogen "backfire" problem and realize stable hydrogen combustion in the large and small annular recirculation vortices formed in the leeward area of ​​the combustion bowl and the V-shaped ring, thereby reducing the formation of local hot spots during the hydrogen combustion process, thereby effectively reducing nitrogen oxide emissions.

[0006] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0007] A concentric pure hydrogen combustion micro-mixing combustion chamber head, comprising:

[0008] A secondary hydrogen fuel nozzle, the secondary hydrogen fuel nozzle is a cylindrical structure, the secondary hydrogen fuel nozzle is provided with an annular fuel channel, and the outer wall of the secondary hydrogen fuel nozzle is provided with a secondary fuel injection hole connected to the annular fuel channel;

[0009] a combustion bowl, wherein the opening edge of the combustion bowl is fixedly connected to the secondary hydrogen fuel nozzle;

[0010] an inner annular hydrogen fuel nozzle housing, the inner annular hydrogen fuel nozzle housing being coaxially sleeved on the outer periphery of the secondary-stage hydrogen fuel nozzle, the inner annular hydrogen fuel nozzle housing being provided with a first fuel passage communicating with the primary-stage fuel pipeline, and the inner annular hydrogen fuel nozzle housing being provided with an inner annular radial injection hole communicating with the first fuel passage;

[0011] an outer annular cavity hydrogen fuel nozzle housing, the outer annular cavity hydrogen fuel nozzle housing being coaxially sleeved on the outer circumference of the inner annular cavity hydrogen fuel nozzle housing, the outer annular cavity hydrogen fuel nozzle housing being provided with a second fuel passage communicating with a primary fuel pipeline, and the outer annular cavity hydrogen fuel nozzle housing being provided with an outer annular radial injection hole communicating with the second fuel passage;

[0012] A V-shaped ring, wherein the inner edge of the opening of the V-shaped ring is fixedly connected to the inner annular cavity hydrogen fuel nozzle housing, and the outer edge of the opening of the V-shaped ring is fixedly connected to the outer annular cavity hydrogen fuel nozzle housing;

[0013] An outer sleeve is coaxially sleeved on the outer periphery of the outer annular cavity hydrogen fuel nozzle housing, and a first convergent channel is formed between the outer sleeve and the outer annular cavity hydrogen fuel nozzle housing along the air flow direction.

[0014] Furthermore, a radial swirler is provided between the inner annular hydrogen fuel nozzle housing and the secondary-stage hydrogen fuel nozzle, and a second convergent channel is formed between the radial swirler and the secondary-stage hydrogen fuel nozzle along the air flow direction, and the outlet end of the secondary-stage fuel nozzle is located in the second convergent channel.

[0015] Furthermore, a diverter ring is provided between the radial swirler and the inner annular cavity hydrogen fuel nozzle housing.

[0016] Furthermore, the diverter ring is fixed to the outer wall of the radial cyclone through a plurality of support blocks, and the plurality of support blocks are evenly distributed along the circumferential direction of the radial cyclone.

[0017] Furthermore, a first grid is provided between the outer wall of the diverter ring and the inner annular cavity hydrogen fuel nozzle housing.

[0018] Furthermore, the front edge of the diverter ring facing the wind is a streamlined structure.

[0019] Furthermore, air film holes are provided on the combustion bowl and the V-shaped ring, and impact plates are respectively provided at the upstream positions of the airflow near the combustion bowl and the V-shaped ring, and impact holes are provided on the impact plates.

[0020] Furthermore, a second grid is provided in the first convergent channel.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention performs micro-premixing on the hydrogen fuel ejected from the secondary fuel nozzle by entraining the air flowing through the outer wall of the secondary hydrogen fuel nozzle, which not only ensures uniform and efficient mixing, but also prevents the "backfire" problem of the secondary hydrogen fuel combustion. By providing a combustion bowl on the secondary hydrogen fuel nozzle, the secondary hydrogen fuel achieves stable hydrogen combustion in the low-operating condition central area downstream of the combustion bowl, and forms a stable low-speed central recirculation area on the leeward side of the combustion bowl. The central recirculation area ensures good combustion stability of the secondary stage.

[0023] 2. The present invention achieves micro-premixing of the main-stage hydrogen fuel ejected from the inner ring radial injection holes and the outer ring radial injection holes with the incoming air respectively, thereby improving the mixing quality and spatial distribution uniformity of the hydrogen fuel during the premixing process, and further avoiding the problem of "backfire" of the main-stage hydrogen fuel combustion; at the same time, when the airflow entrained with the main-stage hydrogen fuel flows through the V-shaped ring, a low-speed and relatively large-scale large-scale annular recirculation vortex structure is formed on the leeward side of the V-shaped ring, and stable combustion is carried out in the large annular recirculation vortex, thereby improving the stability and uniformity of the main-stage hydrogen combustion and reducing NOx emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the concentric pure hydrogen combustion micro-mixing combustion chamber head structure in the embodiment;

[0025] Figure 2 Schematic diagram of the formation of the central recirculation area and the small annular recirculation vortex in the embodiment;

[0026] Figure 3 Schematic diagram of the positional relationship between the inner annular cavity hydrogen fuel nozzle housing and the outer annular cavity hydrogen fuel nozzle housing in the embodiment;

[0027] Figure 4 Schematic diagram of the formation of a large annular recirculation vortex in the embodiment;

[0028] Among them, 1. secondary hydrogen fuel nozzle; 101. annular fuel channel; 102. secondary fuel nozzle hole; 2. combustion bowl; 3. inner annular hydrogen fuel nozzle shell; 301. first fuel channel; 302. inner annular radial injection hole; 4. outer annular hydrogen fuel nozzle shell; 401. second fuel channel; 402. outer annular radial injection hole; 5. V-ring; 6. outer sleeve; 7. first convergent channel; 8. radial swirler; 9. second convergent channel; 10. diverter ring; 11. support block; 12. first grid; 13. air film hole; 14. impact plate; 15. impact hole; 16. second grid; 17. central recirculation area; 18. large annular recirculation vortex; 19. small annular recirculation vortex. DETAILED DESCRIPTION

[0029] The present invention will be described in further detail below with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the present invention to the following embodiments, as all technologies implemented based on the present invention fall within the scope of the present invention.

[0030] Example

[0031] See also Figure 1-Figure 4 , a concentric pure hydrogen combustion micro-mixing combustion chamber head, comprising:

[0032] A secondary hydrogen fuel nozzle 1, which is a cylindrical structure and is provided with an annular fuel channel 101. The outer wall of the secondary hydrogen fuel nozzle 1 is provided with a secondary fuel injection hole 102 connected to the annular fuel channel 101;

[0033] A combustion bowl 2, wherein the opening edge of the combustion bowl 2 is fixedly connected to the secondary hydrogen fuel nozzle 1;

[0034] An inner annular hydrogen fuel nozzle housing 3 is coaxially sleeved on the outer circumference of the secondary hydrogen fuel nozzle 1. A first fuel passage 301 communicating with the primary fuel pipeline is provided inside the inner annular hydrogen fuel nozzle housing 3. An inner annular radial injection hole 302 communicating with the first fuel passage 301 is provided on the inner annular hydrogen fuel nozzle housing 3.

[0035] An outer annular cavity hydrogen fuel nozzle housing 4 is coaxially sleeved on the outer circumference of the inner annular cavity hydrogen fuel nozzle housing 3. A second fuel passage 401 communicating with the primary fuel pipeline is provided in the outer annular cavity hydrogen fuel nozzle housing 4. An outer annular cavity hydrogen fuel nozzle housing 4 is provided with an outer annular radial injection hole 402 communicating with the second fuel passage 401.

[0036] A V-shaped ring 5, wherein the inner edge of the opening of the V-shaped ring 5 is fixedly connected to the inner annular cavity hydrogen fuel nozzle housing 3, and the outer edge of the opening of the V-shaped ring 5 is fixedly connected to the outer annular cavity hydrogen fuel nozzle housing 4;

[0037] The outer sleeve 6 is coaxially sleeved on the outer periphery of the outer annular cavity hydrogen fuel nozzle housing 4 , and a first convergent channel 7 is formed between the outer sleeve 6 and the outer annular cavity hydrogen fuel nozzle housing 4 along the air flow direction.

[0038] In this embodiment, the secondary-stage hydrogen fuel is ejected from the secondary-stage fuel nozzle hole 102 located on the outer wall of the secondary-stage hydrogen fuel nozzle 1. The air flowing through the outer wall of the secondary-stage hydrogen fuel nozzle 1 carries out micro-premixing of the hydrogen fuel ejected from the secondary-stage fuel nozzle hole 102, which not only makes the mixing uniform and efficient, but also prevents the "backfire" problem of the secondary-stage hydrogen fuel combustion. By arranging the combustion bowl 2 on the secondary-stage hydrogen fuel nozzle 1, the secondary-stage hydrogen fuel realizes stable hydrogen combustion in the low-operating condition central area downstream of the combustion bowl 2, and forms a stable low-speed central recirculation area 17 on the leeward side of the combustion bowl 2. The central recirculation area 17 ensures good secondary-stage combustion stability. In addition, a first micro-premixing channel for mixing the main-stage hydrogen fuel ejected from the inner-ring radial injection hole 302 is formed between the inner-ring radial injection hole 302 and the secondary-stage hydrogen fuel nozzle 1, and a second micro-premixing channel for mixing the main-stage hydrogen fuel ejected from the outer-ring radial injection hole 402 is formed between the outer sleeve 6 and the outer-ring radial injection hole 4, which together constitute the main-stage double-ring cavity hydrogen fuel channel; the main-stage hydrogen fuel ejected from the inner-ring radial injection hole 302 and the outer-ring radial injection hole 402 are respectively micro-premixed with the incoming air, and the main-stage hydrogen fuel is entrained. When the hydrogen fuel airflow flows through the V-shaped ring 5, a low-speed and relatively large-scale large annular recirculation vortex 18 structure is formed on the leeward side of the V-shaped ring 5, and stably burns in the large annular recirculation vortex 18, reducing the formation of local hot spots during the hydrogen combustion process, thereby improving the stability and uniformity of the main-stage hydrogen combustion and reducing NOx emissions; the first micro-premixing channel and the second micro-premixing channel play a role in improving the mixing quality and spatial distribution uniformity of the hydrogen fuel during the premixing process, which can further avoid the problem of "backfire" in the main-stage hydrogen fuel combustion.

[0039] In this embodiment, a radial swirler 8 is disposed between the inner annular hydrogen fuel nozzle housing 3 and the secondary hydrogen fuel nozzle 1. A second converging channel 9 is formed between the radial swirler 8 and the secondary hydrogen fuel nozzle 1 along the air flow direction. The outlet end of the secondary fuel nozzle 102 is located within the second converging channel 9. The provision of the radial swirler 8 not only enhances the micro-premixing effect of the secondary hydrogen fuel but also accelerates the airflow entrained with the secondary hydrogen fuel by forming the second converging channel 9 between the radial swirler 8 and the secondary hydrogen fuel nozzle 1, thereby facilitating the stable formation of a central recirculation zone 17 on the leeward side of the combustion bowl 2.

[0040] In this embodiment, a diverter ring 10 is disposed between the radial swirler 8 and the inner annular hydrogen fuel nozzle housing 3. In this structure, the airflow passing between the radial swirler 8 and the inner annular hydrogen fuel nozzle housing 3 is split into two streams by the diverter ring 10. The two streams flow out from the inner and outer channels of the diverter ring 10, respectively, and form a low-speed, small annular recirculating vortex 19 on the leeward side of the diverter ring 10, further ensuring the stable combustion of the primary hydrogen fuel ejected from the inner annular radial injection holes 302. To reduce the disturbance of the diverter ring 10 on the airflow, the windward leading edge of the diverter ring 10 in this embodiment is a streamlined structure.

[0041] In this embodiment, the diverter ring 10 is fixed to the outer wall of the radial cyclone 8 by a plurality of support blocks 11 , and the plurality of support blocks 11 are evenly distributed along the circumference of the radial cyclone 8 , thereby achieving fixation of the diverter ring 10 .

[0042] In this embodiment, a first grid 12 is provided between the outer wall of the diverter ring 10 and the inner annular hydrogen fuel nozzle shell 3, and a second grid 16 is further provided in the first convergent channel 7; the first convergent channel 7 and the convergent channel outside the diverter ring 10 are further subdivided into multi-point array hydrogen jet-cross flow microchannels by the corresponding first grid 12 or second grid 16, thereby achieving uniform mixing of hydrogen fuel and further enhancing the inhibitory effect on the hydrogen "backfire" problem.

[0043] In this embodiment, film holes 13 are formed in both the combustion bowl 2 and the V-ring 5. An impact plate 14 is positioned upstream of the combustion bowl 2 and the V-ring 5, respectively, and each impact plate 14 is provided with impact holes 15. In this embodiment, the impact plate 14 has multiple circumferentially distributed impact holes 15, and the combustion bowl 2 has multiple circumferentially distributed divergent film holes 13. The impact holes 15 and the divergent film holes 13 are staggered in both the radial and circumferential directions. Cooling air from the impact holes 15 on the impact plate 14 flows through the multiple rows of divergent film holes 13 on the combustion bowl 2, forming a wall-adhering airflow that prevents ablation of the combustion bowl 2. Similarly, the impact holes 15 and film holes 13 on the impact plate 14 in front of the V-ring 5 and its corresponding structure can also form a wall-adhering airflow to prevent ablation of the V-ring 5.

[0044] like Figure 1As shown, the impact plate 14 corresponding to the combustion bowl 2 in this embodiment is an arched structure that protrudes away from the combustion bowl 2. The arched impact plate 14 and the combustion bowl 2 are arranged in the center of the head. The arched impact plate 14 is located on the left side of the combustion bowl 2, and its right end is mounted on the periphery of the combustion bowl 2, forming a certain gap between the combustion bowl 2 and the combustion bowl 2. The right end of the secondary hydrogen fuel nozzle 1 overlaps the periphery of the arched impact plate 14 and is welded flush with the outer edge of the combustion bowl 2. The radial swirler 8 is mounted on the outside of the secondary hydrogen fuel nozzle 1, with its right end flush with the right end of the combustion bowl 2. The support block 11 is welded to the periphery of the right end of the radial swirler 8. The diverter ring 10 is radially arranged on the outside of the support block 11, and its right end face is flush with the right end of the radial swirler 8. The outer sleeve 6 is mounted on the outside of the second grid 16, and the outer surface of the outer sleeve 6 is provided with mounting and positioning lugs.

[0045] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A concentric pure hydrogen combustion micro-mixing combustion chamber head, characterized in that: include: A secondary hydrogen fuel nozzle, the secondary hydrogen fuel nozzle is a cylindrical structure, the secondary hydrogen fuel nozzle is provided with an annular fuel channel, and the outer wall of the secondary hydrogen fuel nozzle is provided with a secondary fuel injection hole connected to the annular fuel channel; a combustion bowl, wherein an opening edge of the combustion bowl is fixedly connected to the secondary hydrogen fuel nozzle; an inner annular hydrogen fuel nozzle housing, the inner annular hydrogen fuel nozzle housing being coaxially sleeved on the outer periphery of the secondary-stage hydrogen fuel nozzle, the inner annular hydrogen fuel nozzle housing being provided with a first fuel passage communicating with the primary-stage fuel pipeline, and the inner annular hydrogen fuel nozzle housing being provided with an inner annular radial injection hole communicating with the first fuel passage; an outer annular cavity hydrogen fuel nozzle housing, the outer annular cavity hydrogen fuel nozzle housing being coaxially sleeved on the outer circumference of the inner annular cavity hydrogen fuel nozzle housing, the outer annular cavity hydrogen fuel nozzle housing being provided with a second fuel passage communicating with a primary fuel pipeline, and the outer annular cavity hydrogen fuel nozzle housing being provided with an outer annular radial injection hole communicating with the second fuel passage; A V-shaped ring, wherein the inner edge of the opening of the V-shaped ring is fixedly connected to the inner annular cavity hydrogen fuel nozzle housing, and the outer edge of the opening of the V-shaped ring is fixedly connected to the outer annular cavity hydrogen fuel nozzle housing; An outer sleeve is coaxially sleeved on the outer periphery of the outer annular cavity hydrogen fuel nozzle housing, and a first convergent channel is formed between the outer sleeve and the outer annular cavity hydrogen fuel nozzle housing along the air flow direction.

2. The concentric pure hydrogen combustion micro-mixing combustion chamber head according to claim 1, characterized in that: A radial swirler is provided between the inner annular hydrogen fuel nozzle housing and the secondary-stage hydrogen fuel nozzle. A second convergent channel is formed between the radial swirler and the secondary-stage hydrogen fuel nozzle along the air flow direction. The outlet end of the secondary-stage fuel nozzle is located in the second convergent channel.

3. The concentric pure hydrogen combustion micro-mixing combustion chamber head according to claim 2, characterized in that: A diverter ring is provided between the radial swirler and the inner annular cavity hydrogen fuel nozzle housing.

4. The concentric pure hydrogen combustion micro-mixing combustion chamber head according to claim 3 is characterized in that: The diverter ring is fixed to the outer wall of the radial cyclone through a plurality of support blocks, and the plurality of support blocks are evenly distributed along the circumferential direction of the radial cyclone.

5. The concentric pure hydrogen combustion micro-mixing combustion chamber head according to claim 3, characterized in that: A first grid is provided between the outer wall of the diverter ring and the inner ring cavity hydrogen fuel nozzle housing.

6. The concentric circular pure hydrogen combustion micro-mixing combustion chamber head according to any one of claims 3 to 5, characterized in that: The front edge of the diverter ring facing the wind is a streamlined structure.

7. The concentric pure hydrogen combustion micro-mixing combustion chamber head according to claim 1, characterized in that: Air film holes are provided on the combustion bowl and the V-shaped ring. Impact plates are respectively provided at the upstream positions of the airflow near the combustion bowl and the V-shaped ring, and impact holes are provided on the impact plates.

8. The concentric pure hydrogen combustion micro-mixing combustion chamber head according to claim 1, characterized in that: A second grid is also provided in the first convergent channel.

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