A premixed swirl combustion head and a combustion method

Abstract

The application relates to the hydrogen combustion technical field and discloses a premixing rotary combustion head and a combustion method, an air inlet disc, which is provided with an air inlet pipeline and a plurality of jet pipes arranged along the circumferential direction of the air inlet disc and used for outputting hydrogen entering from the air inlet pipeline; a premixing disc arranged on one side of the air inlet disc, a gap formed between the premixing disc and the air inlet disc and used for air entering into the premixing disc, a plurality of mixing channels arranged on the premixing disc, the mixing channels including premixing sections and rotary sections, the plurality of jet pipes respectively extending into the premixing sections, the premixing sections having diameters larger than that of the jet pipes, and the jet pipes being coaxially arranged with the premixing sections; the plurality of rotary sections converging towards the center of the premixing disc and simultaneously circumferentially deflecting around the center, and used for forming a rotary flow of mixed gas in the premixing sections. The application can realize uniform mixing of hydrogen and air, effectively prevent backfire, improve combustion stability and reduce nitrogen oxide emission.

Description

Technical Field

[0001] This invention relates to the field of hydrogen combustion technology, and discloses a premixed rotary combustion head and combustion method. Background Technology

[0002] The main function of the combustion chamber in aircraft engines and industrial gas turbines is to carry out combustion reactions, converting the chemical energy of fuel into thermal energy, heating the incoming fluid, and improving the working capacity of the working fluid.

[0003] In traditional radial swirl combustor head configurations, fuel is injected into the incoming air at a vertical angle (through cross-flow penetration) to achieve rapid mixing over a short mixing distance. However, the depth of fuel penetration and the trajectory of the fuel jet are affected by the momentum ratio of the fuel jet to the incoming air (J=ρV). j 2 / ρV ∞ 2 The impact of ).

[0004] When the momentum ratio is very low, the fuel penetration depth is shallow, meaning that fuel tends to accumulate on the wall of the mixing section on the same side of the fuel nozzle. Due to viscosity, the flow velocity near the wall is relatively low, increasing the risk of flame entrapment, especially considering the relatively fast flame propagation speed of hydrogen. This implies that in conventional radial cyclones using hydrogen as fuel (cross-flow penetration configuration), the risk of backfire may increase when the momentum is low.

[0005] When the momentum ratio is too high, the hydrogen penetration intensity is too high, and the hydrogen jet reaches and accumulates on the upper wall of the mixing section, which also increases the risk of flame presence on the upper wall.

[0006] Even when the momentum ratio is appropriate, the trajectory and mixing quality of the hydrogen jet will still be affected by the change in momentum ratio caused by the change in operating conditions (from small operating conditions to large operating conditions). This means that the fuel distribution, temperature field distribution and NOx emissions in the downstream combustion zone will also be affected.

[0007] Chinese patent (publication number: CN116481053A) discloses a hydrogen-rich fuel combustion nozzle, a head burner, and a combustion chamber. The combustion working principle of the central combustion unit is as follows: Figure 6 As shown: Fuel passes through the fuel ring channel, flows through the flow channel inside the conical outlet ring, and enters the combustion zone through the fuel injection hole. The fuel injection hole is perpendicular to the outer ring air flow channel. The hole is located downstream of the outer ring air flow channel and has no premixing channel with the outer ring air, which is diffusion combustion. As can be seen from the above-disclosed patent, the perpendicular jetting of the fuel injection hole and the outer ring air flow channel can easily cause backfire.

[0008] Therefore, this application provides a premixed rotary combustion head and combustion method to solve the above-mentioned technical problems. Summary of the Invention

[0009] The purpose of this invention is to provide a premixed rotary combustion head and combustion method that can achieve uniform mixing of hydrogen and air, effectively prevent backfire, improve combustion stability, and reduce nitrogen oxide emissions.

[0010] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is: a premixed rotary combustion head, comprising:

[0011] An air intake plate is provided with an air intake pipe and several injection pipes are provided along the circumference of the center of the air intake plate for outputting hydrogen gas entering from the air intake pipe.

[0012] A premixing disc is located on one side of the intake disc, with a gap between the premixing disc and the intake disc to allow air to enter the premixing disc. The premixing disc has several mixing channels, each including a premixing section and a torsion section. Several injection pipes extend into the premixing section, with the diameter of the premixing section being larger than the diameter of the injection pipes. The injection pipes are coaxially arranged with the premixing section. Several torsion sections converge toward the center of the premixing disc and deflect circumferentially along the center of the premixing disc to form a swirling flow of the mixed gas within the premixing section.

[0013] As a preferred embodiment, the torsion section includes a radial deflection section and a circumferential deflection section, wherein the radial deflection section has an angle of 0-30° with the axis of the premixing disk, and the circumferential deflection section has an angle of 0-60° with the axis of the premixing disk.

[0014] As a preferred embodiment, the air intake plate is provided with a partition, which divides the interior of the air intake plate into an inner air intake chamber and an outer air intake chamber; the air intake pipe includes an inner air intake pipe and an outer air intake pipe, the inner air intake pipe is connected to the inner air intake chamber, and the outer air intake pipe is connected to the outer air intake chamber.

[0015] As a preferred embodiment, the length of the injection pipe extending into the premixing section is 1.3-2.6 mm, so that the hydrogen gas is enveloped by air in the center of the premixing section after injection, reducing the risk of backfire in the wall layer.

[0016] As a preferred embodiment, the length of the premixing section is 3 to 5 times the diameter of the injection pipe to ensure that hydrogen and air are fully mixed in the premixing section to form a uniform premixed gas.

[0017] As a preferred embodiment, the premixing disc is provided with a flame lifting hole, which is concentrically arranged with the air intake disc. The air intake disc is provided with a flame lifting pipe for outputting hydrogen gas in the air intake disc. The flame lifting pipe is coaxially arranged with the flame lifting hole, and the flame lifting pipe extends into the flame lifting hole, with the diameter of the flame lifting hole being larger than the diameter of the flame lifting pipe.

[0018] To achieve the above-mentioned technical effects, the present invention also provides a combustion method for a premixed torsion burner head, comprising the following steps:

[0019] Hydrogen gas is introduced through the intake pipe of the intake disc;

[0020] Hydrogen gas is output through several injection pipes arranged circumferentially along the center of the intake disc;

[0021] Air is allowed to enter the premixing disc through the gap between the intake disc and the premixing disc;

[0022] The hydrogen output from the injection tube is introduced into the premixing section of the mixing channel of the premixing disc. The diameter of the premixing section is larger than that of the injection tube and the two are coaxially arranged. The hydrogen and air are initially mixed in the premixing section.

[0023] The pre-mixed gas is passed through a twisted section that converges towards the center of the premixing disc, forming a swirling flow that further promotes mixing. The pre-mixed gas is then introduced into the combustion chamber for combustion.

[0024] As a preferred embodiment, the torsion section includes a radial deflection section and a circumferential deflection section. The radial deflection section has an angle of 0-30° with the axis of the premixing disk, and the circumferential deflection section has an angle of 0-60° with the axis of the premixing disk. The gas converges towards the center through the radial deflection section, accelerating the outlet velocity of the premixing disk, supporting the flame, and preventing the flame surface from sticking to the outlet wall of the premixing disk and causing burning. When the gas passes through the circumferential deflection section, it forms a swirling flow in a specific direction, forming a stable swirling recirculation zone downstream of the premixing disk, stabilizing the flame within the swirling recirculation zone.

[0025] In a preferred embodiment, the air intake plate is provided with a partition, which divides the interior of the air intake plate into an inner air intake chamber and an outer air intake chamber; the air intake pipe includes an inner air intake pipe and an outer air intake pipe, the inner air intake pipe communicating with the inner air intake chamber and the outer air intake pipe communicating with the outer air intake chamber; the method includes inputting hydrogen gas into the inner air intake pipe and the outer air intake pipe respectively, so that the hydrogen gas enters the inner air intake chamber and the outer air intake chamber respectively.

[0026] As a preferred implementation, the following steps are also included:

[0027] A portion of the hydrogen-air mixture is output through a flame-lifted pipe on the intake disc;

[0028] The hydrogen gas output from the flame lifting pipe is output through the flame lifting hole on the premixing disc, which is coaxially arranged with the flame lifting pipe. The flame lifting pipe extends into the flame lifting hole, and the diameter of the flame lifting hole is larger than the diameter of the flame lifting pipe.

[0029] Compared with the prior art, the beneficial effects of this invention are:

[0030] 1. Uniform mixing: Through the design of the premixing section and the torsion section, hydrogen and air are fully and uniformly mixed, generating a uniform equivalence ratio, avoiding the generation of hot spots, and reducing nitrogen oxide emissions.

[0031] II. Prevention of backfire: The specific length design of the injection pipe extending into the premixing section ensures that the hydrogen is enveloped by air in the center of the premixing section after injection, effectively reducing the risk of backfire in the wall layer.

[0032] 3. Stable combustion: The circumferential deflection of the twisting section forms a swirling flow, which helps stabilize the flame and improve the stability of combustion.

[0033] IV. Head thermal protection: The rotary section deflects radially and converges towards the center, accelerating the flow rate at the premix section outlet and lifting the flame to prevent the flame surface from sticking to the premix plate outlet wall and causing scorching; at the same time, the design of the flame lifting hole and flame lifting pipe at the center also has a similar effect, which helps to lift the bottom of the flame surface.

[0034] V. Flexible control: The intake disc is divided into an inner intake chamber and an outer intake chamber, which can control the hydrogen supply in different areas to adapt to different combustion conditions. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0036] Figure 2 This is one of the main views of the present invention;

[0037] Figure 3 for Figure 2 AA section view;

[0038] Figure 4 for Figure 2 AA solid sectional view;

[0039] Figure 5 This is a partial three-dimensional structural schematic diagram of the present invention;

[0040] Figure 6 This is a schematic diagram of the interior of the premixing disk of the present invention.

[0041] Figure label:

[0042] 1. Intake disc; 11. Intake pipe; 12. Injection pipe;

[0043] 2. Premixing disc; 21. Mixing channel; 210. Premixing section; 211. Twist section; 2111. Radial deflection section; 2112. Circumferential deflection section;

[0044] 3. Partition; 31. Inner air intake chamber; 32. Outer air intake chamber; 33. Inner air intake duct; 34. Outer air intake duct;

[0045] 4. Flame lifting hole; 41. Flame lifting pipe. Detailed Implementation

[0046] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0047] Example 1, as Figure 1 , 2 As shown in Figures 3 and 4, a premixed rotary combustion head includes an intake plate 1 and a premixing plate 2. The intake plate 1 has an intake pipe 11, and several injection pipes 12 are arranged circumferentially along its center for outputting hydrogen gas entering from the intake pipe 11. The premixing plate 2 is located on one side of the intake plate 1, forming a gap between the premixing plate 2 and the intake plate 1 for air to enter the premixing plate 2. The premixing plate 2 has several mixing channels 21, each including a premixing section 210 and a rotary section 211. Several injection pipes 12 extend into the premixing section 210, and the diameter of the premixing section 210 is larger than the diameter of the injection pipes 12. The injection pipes 12 and the premixing section 210 are coaxially arranged. Figure 6 As shown, several of the aforementioned torsion segments 211 converge towards the center of the premixing disk 2, accelerating the airflow at the outlet of the premixing disk 2, supporting the flame, and preventing the flame surface from sticking to the outlet wall of the premixing disk 2 and causing scorching; simultaneously, as Figure 5 As shown, the twisting section 211 deflects circumferentially around the center, forming a swirling flow, which generates a backflow zone downstream for stable combustion.

[0048] As a preferred option in this embodiment, such as Figure 3 , 5 As shown, the torsion section 211 includes a radial deflection section 2111 and a circumferential deflection section 2112. The radial deflection section 2111 has an angle of 0-30° with the axis of the premixing disk 2, and the circumferential deflection section 2112 has an angle of 0-60° with the axis of the premixing disk 2.

[0049] like Figure 3 As shown, the air intake plate 1 is provided with a partition 3, which divides the interior of the air intake plate 1 into an inner air intake chamber 31 and an outer air intake chamber 32; the air intake pipe 11 includes an inner air intake pipe 33 and an outer air intake pipe 34, the inner air intake pipe 33 is connected to the inner air intake chamber 31, and the outer air intake pipe 34 is connected to the outer air intake chamber 32.

[0050] like Figure 3As shown, the length of the injection pipe 12 extending into the premixing section 210 is 1.3-2.6 mm, so that the hydrogen gas is enveloped by air at the center of the premixing section 210 after injection, reducing the risk of backfire of the wall layer.

[0051] The length of the premixing section 210 is 3 to 5 times the diameter of the injection pipe 12, ensuring that hydrogen and air are fully mixed in the premixing section 210 to form a uniform premixed gas.

[0052] like Figure 2 , 3 As shown, the premixing disk 2 is provided with a flame lifting hole 4, and the air intake disk 1 is provided with a flame lifting pipe 41 for outputting hydrogen in the air intake disk 1. The flame lifting pipe 41 is coaxially arranged with the flame lifting hole 4, the flame lifting pipe 41 extends into the flame lifting hole 4, and the diameter of the flame lifting hole 4 is larger than the diameter of the flame lifting pipe 41.

[0053] In use, the premixed rotary combustion head of the present invention includes an air intake plate 1 and a premixing plate 2. The air intake plate 1 is provided with an air intake pipe 11, which includes an inner air intake pipe 33 and an outer air intake pipe 34. A partition 3 is provided inside the air intake plate 1, which divides the interior of the air intake plate 1 into an inner air intake chamber 31 and an outer air intake chamber 32. The inner air intake pipe 33 communicates with the inner air intake chamber 31, and the outer air intake pipe 34 communicates with the outer air intake chamber 32.

[0054] Several injection pipes 12 are arranged circumferentially along the center of the intake plate 1 to output hydrogen gas entering from the intake pipe 11. The premixing plate 2 is located on one side of the intake plate 1, and a gap is formed between the premixing plate 2 and the intake plate 1 to allow air to enter the premixing plate 2.

[0055] The premixing disc 2 is provided with several mixing channels 21, each including a premixing section 210 and a torsion section 211. Several injection pipes 12 extend into the premixing section 210, with the diameter of the premixing section 210 being larger than the diameter of the injection pipes 12. The injection pipes 12 are coaxially arranged with the premixing section 210. The length of the injection pipes 12 extending into the premixing section 210 is 1.3-2.6 mm, and the length of the premixing section 210 is 3-5 times the diameter of the injection pipes 12.

[0056] like Figure 2 , 3 As shown in Figure 5, the torsion section 211 includes a radial deflection section 2111 and a circumferential deflection section 2112. The radial deflection section 2111 has an angle δ of 0-30° with the axis of the premixing disk 2, and the circumferential deflection section 2112 has an angle θ of 0-60° with the axis of the premixing disk 2.

[0057] like Figure 6As shown, several twisting sections 211 converge towards the center of the premixing disk 2, which accelerates the gas mixture in the premixing section 210 at the outlet of the premixing disk 2, supports the flame, and prevents the flame surface from sticking to the outlet wall of the premixing disk 2 and causing burning; at the same time, as Figure 6 As shown, the twisting section 211 deflects circumferentially around the center, forming a swirling flow, which generates a backflow zone downstream for stable combustion.

[0058] like Figure 2 , 3 As shown, the premixing disc 2 is provided with a flame lifting hole 4, and the intake disc 1 is provided with a flame lifting pipe 41 for outputting hydrogen gas from the intake disc 1. The flame lifting pipe 41 is coaxially arranged with the flame lifting hole 4, and the flame lifting pipe 41 extends into the flame lifting hole 4. The diameter of the flame lifting hole 4 is larger than the diameter of the flame lifting pipe 41 to prevent the flame surface from sticking to the combustion head wall and causing scorching.

[0059] Example 2, a combustion method for a premixed torsion burner head, based on the above-mentioned premixed torsion burner head, includes the following steps:

[0060] Hydrogen gas is introduced through the intake pipe 11 of the intake disc 1;

[0061] Hydrogen gas is output through a number of injection pipes 12 arranged circumferentially along the center of the intake disk 1;

[0062] Air is allowed to enter the premixing disk 2 through the gap between the intake disk 1 and the premixing disk 2;

[0063] The hydrogen output from the injection pipe 12 is introduced into the premixing section 210 of the mixing channel 21 of the premixing disk 2. The diameter of the premixing section 210 is larger than that of the injection pipe 12 and the two are coaxially arranged. The hydrogen and air are initially mixed in the premixing section 210.

[0064] The pre-mixed gas is passed through the torsion section 211 that converges towards the center of the premixing disk 2, forming a swirling flow, which further promotes mixing, and the premixed gas is introduced into the combustion chamber for combustion.

[0065] Through the above structure and method, the present invention achieves uniform mixing of hydrogen and air, effectively prevents backfire, improves combustion stability, and reduces nitrogen oxide emissions, and has good application prospects.

[0066] The above are merely 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 within the protection scope of the present invention.

Claims

1. A premixed swirl combustion head, characterized by, It comprises: An air inlet disc (1) provided with an air inlet pipe (11) and a plurality of jet pipes (12) arranged along the circumferential direction of the air inlet disc (1) to output hydrogen entering from the air inlet pipe (11); A premixing disc (2) arranged on one side of the air inlet disc (1) and forming a gap with the air inlet disc (1) for air to enter the premixing disc (2), the premixing disc (2) being provided with a plurality of mixing channels (21), each of the mixing channels (21) comprising a premixing section (210) and a swirl section (211), a plurality of the jet pipes (12) respectively extending into the premixing section (210), the premixing section (210) having a diameter larger than that of the jet pipe (12), and the jet pipe (12) being coaxially arranged with the premixing section (210); a plurality of the swirl sections (211) converging towards the center of the premixing disc (2) and being deflected along the circumferential direction of the premixing disc (2) to form a swirling flow of the mixed gas in the premixing section (210).

2. The premix swirl combustion head of claim 1, wherein The swirl section (211) comprises a radial deflection section (2111) and a circumferential deflection section (2112), the radial deflection section (2111) being arranged at an angle of 0-30° with the axis of the premixing disc (2), and the circumferential deflection section (2112) being arranged at an angle of 0-60° with the axis of the premixing disc (2).

3. The premix swirl combustion head of claim 1, wherein, The air inlet disc (1) is provided with a partition plate (3) dividing the air inlet disc (1) into an inner air inlet chamber (31) and an outer air inlet chamber (32); the air inlet pipe (11) comprises an inner air inlet pipe (33) and an outer air inlet pipe (34), the inner air inlet pipe (33) being communicated with the inner air inlet chamber (31), and the outer air inlet pipe (34) being communicated with the outer air inlet chamber (32).

4. The premix swirl combustion head of claim 1, wherein, The length of the jet pipe (12) extending into the premixing section (210) is 1.3-2.6 mm, so that the hydrogen is wrapped by air at the center position of the premixing section (210) to reduce the risk of wall layer tempering.

5. The premix swirl combustion head of claim 1, wherein, The length of the premixing section (210) is 3-5 times the diameter of the jet pipe (12), so as to ensure that the hydrogen and air are fully mixed in the premixing section (210) to form a uniform premixed gas.

6. The premix swirl combustion head of claim 1, wherein, The premixing disc (2) is provided with a flame lifting hole (4) arranged concentrically with the premixing disc (2), and the air inlet disc (1) is provided with a flame lifting pipe (41) for outputting hydrogen in the air inlet disc (1), the flame lifting pipe (41) being coaxially arranged with the flame lifting hole (4), the flame lifting pipe (41) extending into the flame lifting hole (4), and the diameter of the flame lifting hole (4) being larger than that of the flame lifting pipe (41).

7. A combustion method for a premixed swirl combustion head, characterized by, The premixing and swirl combustion head according to any one of claims 1-6, comprising the following steps: Inputting hydrogen through the air inlet pipe (11) of the air inlet disc (1); Outputting the hydrogen through a plurality of jet pipes (12) arranged along the circumferential direction of the air inlet disc (1); Making the air enter the premixing disc (2) through the gap between the air inlet disc (1) and the premixing disc (2); The hydrogen gas outputted by the injection pipe (12) enters the premixing section (210) of the mixing channel (21) of the premixing disc (2), the premixing section (210) has a diameter larger than that of the injection pipe (12) and is coaxially arranged with the injection pipe (12), and the preliminary mixing of the hydrogen gas and the air is realized in the premixing section (210); The preliminarily mixed gas passes through the swirl section (211) converging to the center of the premixing disc (2), the swirl is formed to promote the mixing, and the premixed gas is introduced into the combustion chamber for combustion.

8. The combustion method of a pre-mixing swirl combustion head according to claim 7, characterized by, The swirl section (211) comprises a radial deflection section (2111) and a circumferential deflection section (2112), the radial deflection section (2111) has an angle of 0-30° with the axis of the premixing disc (2), and the circumferential deflection section (2112) has an angle of 0-60° with the axis of the premixing disc (2), the gas converges to the center through the radial deflection section (2111), the outlet speed of the premixing disc (2) is accelerated, the flame is lifted, the adhesion between the flame surface and the premixing disc (2) is reduced, and the risk of ablation is avoided; when the gas passes through the circumferential deflection section (2112), the swirl with an angle of 0-60° with the axis of the premixing disc (2) is formed, and the stable swirl backflow area is formed downstream of the premixing disc (2), so that the flame is stabilized in the swirl backflow area.

9. The combustion method of a pre-mixing swirl combustion head according to claim 8, characterized by, The air inlet disc (1) is provided with a partition plate (3), the partition plate (3) divides the air inlet disc (1) into an inner air inlet chamber (31) and an outer air inlet chamber (32); the air inlet pipeline (11) comprises an inner air inlet pipeline (33) and an outer air inlet pipeline (34), the inner air inlet pipeline (33) communicates with the inner air inlet chamber (31), and the outer air inlet pipeline (34) communicates with the outer air inlet chamber (32); the method comprises the steps of inputting the hydrogen gas into the inner air inlet pipeline (33) and the outer air inlet pipeline (34) respectively, so that the hydrogen gas enters the inner air inlet chamber (31) and the outer air inlet chamber (32) respectively.

10. The combustion method of a pre-mixing swirl combustion head according to claim 9, characterized by, The method further comprises the following steps: Part of the mixed gas of the hydrogen gas and the air is outputted through the flame lifting hole (4) on the premixing disc (2); The hydrogen gas outputted by the flame lifting hole (4) is outputted through the flame lifting pipeline (41) on the air inlet disc (1) coaxially arranged with the flame lifting hole (4), the flame lifting pipeline (41) extends into the flame lifting hole (4), and the diameter of the flame lifting hole (4) is larger than that of the flame lifting pipeline (41).

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