A diffusion combustion chamber head injection structure

Abstract

The application discloses a diffusion combustion chamber head injection structure, belonging to the technical field of hydrogen fuel gas turbines; an inner swirler, a hydrogen fuel conveyor and an outer swirler are coaxially arranged from inside to outside; the outer swirler is an annular cavity, and sequentially comprises an outer swirler inlet, an outer swirler blade, a transition section and a converging-expanding section along an axial direction; the converging-expanding section is composed of a converging section and an expanding section; the inner swirler is a coaxial coupling structure of a blocking body and a swirler cavity; the hydrogen fuel conveyor is coaxially arranged between the inner swirler and the outer swirler, and sequentially comprises a gas supply pipe, a gas collecting ring, a gas distribution channel, a gas storage chamber and an injection outlet hole along the axial direction; the swirler air of the outer swirler and the swirler air and non-swirler air of the inner swirler are mixed in the expanding section and the flame tube to form a detached flame to isolate a high-temperature combustion zone; the application optimizes the mixing effect of hydrogen fuel and airflow, realizes low nitrogen oxide emission capacity, and effectively avoids the risk of ablation of the diffusion structure device.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrogen fuel gas turbine, and particularly relates to a diffusion type combustion chamber head injection structure. BACKGROUND

[0002] With the increasingly strict pollution emission requirements for gas turbines in the world, the power transmission by using traditional kerosene as fuel will not be able to meet the low emission requirements. Hydrogen, as a valuable clean energy, has great potential in the future gas turbine market; therefore, it is necessary to develop a combustion chamber head injection structure suitable for pure hydrogen combustion. At present, from the mixing mode of hydrogen fuel and air, the hydrogen fuel combustion chamber head injection structure is mainly divided into two types of premixed combustion type and diffusion combustion type. Among them, the premixed type structure is mainly represented by a lean premixed injection unit, which usually includes a premixing section or a premixing cavity; and the diffusion type structure is represented by a lean direct injection unit, which usually only includes a partial transition section.

[0003] However, the existing hydrogen fuel premixed type structure generally has a high risk of backfire and spontaneous combustion; compared with the premixed type structure, the diffusion type structure itself has good anti-backfire and anti-spontaneous combustion properties and stable combustion. However, the conventional diffusion type structure usually only includes a partial transition section, and the hydrogen fuel and air are mainly mixed in the flame tube, and the short mixing time and uneven mixing are easy to cause the combustion temperature to be too high, and the thermal type nitrogen oxide emission is large. At the same time, on the basis of using hydrogen as fuel, since the hydrogen flame propagation speed is fast, the position of the backflow area will affect whether the hydrogen fuel diffusion type structure device is ablated by the flame.

[0004] Therefore, the application provides a hydrogen fuel diffusion type combustion chamber head injection structure. SUMMARY

[0005] Technical problems to be solved:

[0006] In order to avoid the shortcomings of the prior art, the application provides a hydrogen fuel diffusion type combustion chamber head injection structure, which couples a hydrogen fuel delivery device between an outer swirler and an inner swirler, reasonably arranges the hydrogen fuel injection hole space, and adopts the technical modes of non-swirl air combined with swirl air, two-stage swirler air flow distribution, and converging-diverging section at the outlet, so as to optimize the mixing effect of hydrogen fuel and airflow, realize low nitrogen oxide emission capacity, and effectively avoid the ablation risk of the diffusion type structure device.

[0007] The technical scheme of the application is: a diffusion type combustion chamber head injection structure, an inner swirler, a hydrogen fuel delivery device and an outer swirler are coaxially arranged from inside to outside in sequence, and air and hydrogen fuel are respectively introduced into a flame tube for uniform mixing.

[0008] The outer swirler is an annular cavity, which comprises an outer swirler inlet, an outer swirler blade, a transition section and a converging-diverging section in sequence along the axial direction, and the converging-diverging section is composed of a converging section and a diverging section; the converging angle of the converging section is 135°, the diverging angle of the diverging section is 45°, and the ratio of the axial length of the diverging section to the converging section is not less than 1 / 2.

[0009] The inner swirler is a coaxial coupling structure of a blocking body and a swirler cavity; the blocking body is a cylindrical body with a converging end, and a plurality of non-swirling holes are formed on the end face of the blocking body along the axial direction; the swirler cavity is an annular cavity, which comprises an inner swirler inlet, an inner swirler blade, an inner swirler outlet converging section in sequence along the axial direction, and a cooling hole is arranged on the converging wall surface of the inner swirler outlet converging section and communicates the swirler cavity and the flame tube; wherein the outlet face of the non-swirling hole is flush with the throat of the converging-diverging section of the outer swirler.

[0010] The hydrogen fuel feeder is coaxially arranged between the inner swirler and the outer swirler, and comprises a gas supply pipe, a gas collecting ring, a distribution gas channel, a gas storage chamber and a jet outlet hole in sequence along the axial direction; the gas collecting ring is a circular annular cavity which is communicated between the gas supply pipe and the distribution gas channel; the gas storage chamber is an annular cavity which is communicated downstream of the distribution gas channel, and the end thereof is a converging outlet section which is arranged opposite to the converging section of the outer swirler, and a plurality of jet outlet holes are uniformly distributed on the end face of the end along the circumferential direction, and the outlet face of the jet outlet hole is aligned with the throat of the converging-diverging section.

[0011] The swirling air of the outer swirler, the swirling air of the inner swirler and the non-swirling air are mixed in the diverging section and the flame tube to form a detached flame to isolate the high-temperature combustion zone.

[0012] Further technical solutions of the present application are that the number of the outer swirler blades of the outer swirler is 12, the blade angle is 40°, the diameter of the inner hub of the outer swirler is equal to the outer diameter of the gas storage chamber, and the swirling air flowing through the outer swirler accounts for 60%-67% of the total incoming air.

[0013] Further technical solutions of the present application are that the axial length of the transition section exceeds 1 / 2 of the axial length of the inner hub of the outer swirler, and is used for adjusting the tangential momentum of the swirling air.

[0014] Further technical solutions of the present application are that the outer diameter of the inner swirler is equal to the inner diameter of the gas storage chamber, the non-swirling hole thereon is a circular small hole, the ratio of the flow area of the non-swirling hole to the area of the blocking body is 1 / 5-2 / 5, and the amount of non-swirling air accounts for 6.5%-10% of the total incoming air.

[0015] Further technical solutions of the present application are that two circles of circular cooling holes are formed on the converging wall surface of the inner swirler, and the axial direction of the cooling holes is parallel to the axial direction of the outer swirler.

[0016] The further technical scheme of the present application is that the distribution air duct of the hydrogen fuel feeder is composed of four axisymmetric gas supply pipes for uniformly supplying hydrogen to the gas storage chamber.

[0017] The further technical scheme of the present application is that the injection outlet hole diameter of the hydrogen fuel feeder is 0.5 mm, and the holes are uniformly arranged in two circles with a radial distance of 1 mm between the two circles, and the radial distance between the inner circle and the central axis of the inner swirler is 6.5 mm.

[0018] The further technical scheme of the present application is that the effective flow area of the hollow ring cavity of the gas storage chamber of the hydrogen fuel feeder is equal to the geometric area of the inner hub of the inner swirler, so as to ensure the proportion of non-swirling air.

[0019] The further technical scheme of the present application is that the outer swirler, the inner swirler and the fuel feeder are designed in an integrated manner or mechanically connected.

[0020] The further technical scheme of the present application is that the non-swirling holes are arranged in five circles at equal radial distances, and the number of holes in each circle is 1, 6, 12, 24 and 40 respectively, and the radial distance between the two adjacent circles is 1.1 mm.

[0021] Beneficial effects

[0022] The beneficial effects of the present application are that the lean direct injection combustion organization technology is adopted to directly inject hydrogen fuel into the flame tube, mix with the excess swirling air and non-swirling air passing through the inner and outer swirler, and the combustion organization technology combined with the low backfire and self-ignition risk of diffusion combustion has stable combustion process and is not easy to occur oscillation combustion, and can effectively improve the emission of thermal nitrogen oxides in the hydrogen combustion process. The specific advantages are analyzed as follows:

[0023] 1. Reducing nitrogen oxide emission. The outer swirler of the present application connects the transition section with the rear converging-diverging section, the transition section is used to adjust and strengthen the tangential momentum of part of the incoming swirling air, and the swirling air is orderly delivered to the rear converging-diverging section; by reasonably designing the axial length ratio of the converging section and the diverging section, the converging angle and the diverging angle; the ratio between the diverging section and the converging section is greater than 1 / 2, the diverging angle is 135°, and the converging angle is 45°, forming an axisymmetric shape along the throat, which is beneficial to strengthening the mixing effect of the outer swirling air and the hydrogen fuel, and the gas entering the flame tube is more uniform, thereby achieving the purpose of reducing nitrogen oxide emission.

[0024] The gas supply pipe of the present application supplies hydrogen fuel to the gas collecting ring, and the hydrogen fuel is uniformly supplied to the axisymmetric distribution air duct, and finally the hydrogen fuel is sprayed out from the injection outlet in a circumferentially uniform manner, ensuring the uniformity of hydrogen in the flame tube.

[0025] 2. Avoiding device ablation. The inner swirler of the present application arranges five non-swirling air holes in staggered arrangement on the inner hub column, adjusts the non-swirling air volume and the non-swirling air axial flow rate by reasonably designing the non-swirling hole diameter and the number of holes, resists the hydrogen fuel flame burning speed, and finally determines that when the non-swirling air volume accounts for 6.5%-10% of the total airflow volume, the detached flame can be effectively formed in the flame tube, thereby isolating the high-temperature combustion zone from the hydrogen fuel diffusion-type injection unit structure; and can reasonably ensure sufficient outer swirling air and inner swirling air flow to shear the hydrogen fuel to form a good uniformity of the gas; the non-swirling air outlet surface is flush with the throat of the converging-diverging section of the swirler, and is in the same plane with the hydrogen fuel outlet, realizing the ability of non-swirling air and swirling air to jointly strengthen the mixing of hydrogen fuel in the flame tube, and achieving the purpose of avoiding structural device ablation and strengthening hydrogen combustion by using a small amount of non-swirling air.

[0026] 3. Improve combustion efficiency. The present application adopts the layout of non-swirling holes, inner swirler, fuel feeder and outer swirler from inside to outside, the jet air injected by the non-swirling holes will directly resist the hydrogen combustion flame propagation speed, and reach equilibrium at the front of the flame tube center recirculation zone to stabilize the flame combustion; the inner swirling air expands radially in the flame tube, drives the hydrogen fuel to move outward, and further mixes with the swirling air from the outer swirler, and performs turbulent motion in the shear layer formed by the combined action of inner and outer swirling air; realizes the ability of hydrogen fuel to mix with multiple swirling air and non-swirling air in the outer swirler expansion section and the flame tube at the same time, and achieves the ability of superior hydrogen fuel combustion. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is the explosion schematic diagram of the head structure of the hydrogen fuel diffusion-type combustion chamber of the present application;

[0028] Figure 2 is the outer swirler structure schematic diagram of the present application;

[0029] Figure 3 is the outer swirler sectional view of the present application;

[0030] Figure 4 is the front view schematic diagram of the inner swirler structure of the present application;

[0031] Figure 5 is the back view schematic diagram of the inner swirler structure of the present application;

[0032] Figure 6 is the sectional view of the inner swirler of the present application;

[0033] Figure 7 is the fuel feeder structure schematic diagram of the present application;

[0034] Figure 8This is a cross-sectional view of the fuel conveyor of the present invention;

[0035] Figure 9 This is a schematic diagram of the gas storage chamber structure of the present invention;

[0036] Figure 10 This is an assembly cross-sectional view of the hydrogen fuel diffusion type combustion chamber head structure of the present invention.

[0037] Figure 11 This is a schematic diagram of the working process of the hydrogen fuel diffusion-type combustion chamber head structure of the present invention (without non-swirling orifices).

[0038] Figure 12 This is a schematic diagram of the working process of the hydrogen fuel diffusion-type combustion chamber head structure of the present invention (with non-swirling orifices).

[0039] Explanation of reference numerals in the attached figures: 1-Outer cyclone separator, 11-Outer cyclone inlet, 12-Outer cyclone blade, 13-Transition section, 14-Converging-expanding section, 15-Outer converging section, 16-Outer expanding section, 17-Throat, 18-Inner hub of the outer cyclone separator, 2-Inner cyclone separator, 21-Inner cyclone inlet, 22-Inner cyclone blade, 23-Non-cyclone orifice, 24-Block, 25-Inner cyclone outlet surface, 26-Non-cyclone orifice outlet surface 27-Inner converging section, 28-Cooling hole, 29-Inner swirl outlet converging section, 210-Inner hub of inner swirl generator, 3-Fuel conveyor, 31-Gas supply pipe, 32-Gas collecting ring, 33-Distribution gas passage, 34-Gas storage chamber, 35-Hydrogen fuel outlet converging section, 36-Non-swirl air inlet, 37-Hollow annular cavity, 38-Inner wall of gas storage chamber, 39-Injection outlet, 310-Gas storage chamber outlet, 311-Gas delivery pipe. Detailed Implementation

[0040] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] Based on the problems of low mixing effect of hydrogen fuel and incoming air in conventional hydrogen fuel combustion chamber head injection structure, large emission of thermal nitrogen oxides, and risk of erosion, this invention provides a diffusion type combustion chamber head injection structure, in which an inner swirler, a hydrogen fuel conveyor, and an outer swirler are arranged coaxially from the inside to the outside, respectively, to introduce air and hydrogen fuel into the flame tube for uniform mixing.

[0043] The external vortex is an annular cavity, which includes an external vortex inlet, external vortex blades, a transition section, and a convergence-expansion section in sequence along the axial direction. The convergence-expansion section consists of a convergence section and an expansion section. The convergence angle of the convergence section is 135°, the expansion angle of the expansion section is 45°, and the ratio of the axial length of the expansion section to the convergence section is not less than 1 / 2.

[0044] The inner vortex generator is a coaxially coupled structure of a blocking body and a vortex cavity; the blocking body is a cylindrical body that converges at the end, with several non-vortex holes opened along the axial direction on its end face; the vortex cavity is an annular cavity that includes an inner vortex inlet, an inner vortex blade, and an inner vortex outlet convergence section in sequence along the axial direction, and a cooling hole connecting the vortex cavity and the flame tube is provided on the convergence wall of the inner vortex outlet convergence section; wherein, the outlet surface of the non-vortex holes is flush with the throat of the convergence-expansion section of the outer vortex generator;

[0045] The hydrogen fuel delivery unit is coaxially disposed between the inner cyclone and the outer cyclone, and includes, in sequence along the axial direction, a gas supply pipe, a gas collecting ring, a gas distribution channel, a gas storage chamber, and an injection outlet hole; the gas collecting ring is an annular cavity connecting the gas supply pipe and the gas distribution channel; the gas storage chamber is an annular cavity connected downstream of the gas distribution channel, and its end is a convergence outlet section disposed opposite to the convergence section of the outer cyclone, and multiple injection outlet holes are evenly distributed circumferentially on the end face of the end, and the outlet surface of the injection outlet hole is aligned with the throat of the convergence-expansion section;

[0046] The swirling air from the outer swirler, the swirling air from the inner swirler, and the non-swirling air mix in the expansion section and the flame tube to form a detached flame to isolate the high-temperature combustion zone.

[0047] The above technical solution will be further explained below with reference to the accompanying drawings:

[0048] In one embodiment, refer to Figure 1 As shown, this embodiment of a diffusion-type combustion chamber head injection structure includes an outer swirler 1, an inner swirler 2, and a coaxial fuel delivery device 3.

[0049] In one embodiment, refer to Figure 2 , 3As shown, the outer swirler 1 body part is an outer swirler vane 12, preferably, the swirl angle of the outer swirler vane 12 is 40°, and the swirl direction is clockwise rotation, that is, from the flow direction of the swirl air, the blade rotation direction is the normal clockwise direction; the axial length of the outer swirler inner hub 18 is 10mm, which ensures that the light transmission principle is met, and the flow air passing through the swirler 1 is all swirl air, and no jet flow is generated; the swirler 1 and the coaxial gas storage chamber 34 are flush at the inlet surface, and the outer swirler 1 and the gas storage chamber 34 are connected by mechanical connection.

[0050] It should be noted that the rear end of the swirler vane 12 is a transition section 13, and the inner wall of the transition section 13 is uniformly equal in diameter from front to back; the swirl air passing through the swirler vane 12 adjusts the irregular rotational direction fluctuation in the transition section 13 to enter the converging-diverging section 14 at the rear end with a suitable tangential momentum; preferably, the axial length of the transition section 13 is 5mm, which is kept at 1 / 2 or more of the axial length of the swirler inner hub 18; in the converging-diverging section 14, the axial length of the converging section 15 is 5mm, the converging angle is 135°, the axial length of the diverging section 16 is 2.5mm, and the diverging angle is 45°, the axial length ratio of the diverging section 16 to the converging section 15 is kept at 1 / 2 or more, which can effectively strengthen the gas mixing.

[0051] In one embodiment, referring to Figure 4 , 5 , 6, the inner swirler 2 body part includes an inner swirler vane 22, preferably, the swirl angle of the inner swirler vane 22 is 38°, and the swirl direction is clockwise rotation, which ensures that the swirl intensity generated by the inner swirler vane is equal to the swirl intensity generated by the outer swirler vane, and effectively controls the hydrogen fuel in the shear layer. The inner swirler inner hub 210 is a cylinder with an inner converging outlet section 27, preferably, the diameter of the inner swirler inner hub 210 is 10mm; the outlet surface 26 thereof is aligned with the throat 17 of the outer swirler converging-diverging section, that is, it is arranged at a position close to the inlet of the flame tube; a strong jet flow is formed by the non-swirl gas to effectively resist the high flame burning speed of the downstream hydrogen, thereby forming a detached flame inside the flame tube, isolating the high-temperature combustion zone from the hydrogen fuel diffusion-type injection unit structure, and effectively avoiding the ablation of the structural device; the relative installation between the inner swirler 2 and the fuel feeder 3 can be achieved by mechanical connection or integrated design; a plurality of non-swirl holes 23 of the same diameter are arranged on the inner swirler 2, the diameter of the non-swirl hole 23 is optimized to be 0.6mm, the holes are arranged in 5 circles at equal radial distances, the number of holes in the first circle is 1, the number of holes in the second, third, and fourth circles is 6, 12, 24, and 40 respectively; the radial distance between the circles is preferably 1.1mm, and the non-swirl holes 23 on each circle are uniformly arranged in the circumferential direction; the effective flow area of the non-swirl holes 23 is 13.65mm 2, and the non-swirl air accounts for 6.5%-10% of the total air flow, so that the swirl air mainly enhances the gas mixing by the swirl effect, and the non-swirl air mainly injects hydrogen.

[0052] In one embodiment, referring to Figure 7 , 8 , 9, the inlet end of the fuel feeder 3 is a gas supply pipe 31, the diameter of the gas supply pipe 31 is optimized to be 4 mm, and the axis of the gas supply pipe 31 is parallel to the axis of the swirler 1. From the axis direction, the axis of the gas supply pipe 31 is located in the middle of the axes of any two gas supply pipes 311 in the distribution gas channel 33. The gas supply pipe 31 is connected to the gas collecting ring 32 through integrated design. The inside of the gas collecting ring 32 is a hollow cavity, and the height of the cavity is equal to the diameter of the gas supply pipe 31, so as to ensure stable delivery of hydrogen to the distribution gas channel 33 at the other end. Through optimization design, the distribution gas channel mainly consists of four gas supply pipes 311 which are axially symmetrical to each other, so as to ensure that the hydrogen enters the gas storage chamber 34 in a uniform manner. In addition, the main part of the gas storage chamber 34 is a larger hollow cavity, and the height of the cavity is greater than the inner diameter of the gas supply pipe 311, so as to further weaken the axial velocity of the hydrogen flow.

[0053] It is worth noting that, since the main part of the gas storage chamber 34 is a hollow cavity for storing hydrogen, the inner wall 38 of the gas storage chamber constitutes a flow path before the non-swirl air enters the non-swirl hole 23. Through optimization design, the effective flow area of the flow path is equal to the geometric area of the inner hub 210 of the inner swirler, which is equivalent to a circular pipe with a diameter of 10 mm, so as to as far as possible to affect the effective flow area of the non-swirl hole behind, and to ensure that the amount of non-swirl air is in a suitable proportion of 6.5%-10%. The rear end of the gas storage chamber 34 is a converging outlet section 35, the axial length of which is preferably 3 mm, and the converging angle is 135°. The converging outlet section 35 constitutes an expansion flow path for the swirl air coming out of the outer swirler 1, so as to ensure that part of the swirl air can quickly mix with the hydrogen fuel in the expansion section 16 of the converging-expansion section 14. The outlet face 310 of the gas storage chamber is arranged with injection outlets 39. By preferably selecting the injection outlets 39 as circular injection holes with a diameter of 0.5 mm, the number of injection holes is 48, and the layout presents two circumferentially uniform arrangements. The radial distance between the two circles is 1 mm. The side close to the inner swirler 2 is called the inner circle, and the side close to the outer swirler 1 is called the outer circle. The radial distance between the inner circle and the center axis of the inner swirler is 6.5 mm, which ensures that the distance between the injection outlets 39 of the inner circle and the non-swirl air flowing through the non-swirl hole 23 of the inner swirler is closer, and is conducive to fully utilizing the air entering the flame tube through the spatial layout.

[0054] In one embodiment, referring to Figure 10As shown, the plenum outlet face 310 is also aligned with the converging-diverging section throat 17, ensuring that hydrogen fuel exiting the injection outlet 39 can be rapidly mixed with the swirled air from the outer swirler 1, the swirled air from the inner swirler 2, and the non-swirled air in the diverging section 16, enhancing the mixing effect.

[0055] It is noted that the structure of the present application can be integrated with the outer swirler 1, the inner swirler 2, and the fuel feeder 3 according to the needs of the use, and is not limited to mechanical connection.

[0056] Although the embodiments of the present application have been shown and described above, it is to be understood that the above-described embodiments are exemplary only, and are not to be understood as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the principles and spirit of the present application.

Claims

1. A diffusion-type combustion chamber head injection structure, characterized in that: The inner cyclone separator, hydrogen fuel delivery device, and outer cyclone separator, arranged coaxially from the inside to the outside, respectively introduce air and hydrogen fuel into the flame tube for uniform mixing. The external vortex is an annular cavity, which includes an external vortex inlet, external vortex blades, a transition section, and a convergence-expansion section in sequence along the axial direction. The convergence-expansion section consists of a convergence section and an expansion section. The convergence angle of the convergence section is 135°, the expansion angle of the expansion section is 45°, and the ratio of the axial length of the expansion section to the convergence section is not less than 1 / 2. The inner vortex generator is a coaxially coupled structure of a blocking body and a vortex cavity; the blocking body is a cylindrical body that converges at the end, with several non-vortex holes opened along the axial direction on its end face; the vortex cavity is an annular cavity that includes an inner vortex inlet, an inner vortex blade, and an inner vortex outlet convergence section in sequence along the axial direction, and a cooling hole connecting the vortex cavity and the flame tube is provided on the convergence wall of the inner vortex outlet convergence section; wherein, the outlet surface of the non-vortex holes is flush with the throat of the convergence-expansion section of the outer vortex generator; The hydrogen fuel delivery unit is coaxially disposed between the inner cyclone and the outer cyclone, and includes, in sequence along the axial direction, a gas supply pipe, a gas collecting ring, a gas distribution channel, a gas storage chamber, and an injection outlet hole; the gas collecting ring is an annular cavity connecting the gas supply pipe and the gas distribution channel; the gas storage chamber is an annular cavity connected downstream of the gas distribution channel, and its end is a convergence outlet section disposed opposite to the convergence section of the outer cyclone, and multiple injection outlet holes are evenly distributed circumferentially on the end face of the end, and the outlet surface of the injection outlet hole is aligned with the throat of the convergence-expansion section; The swirling air from the outer swirler, the swirling air from the inner swirler, and the non-swirling air mix in the expansion section and the flame tube to form a detached flame to isolate the high-temperature combustion zone.

2. The diffusion-type combustion chamber head injection structure according to claim 1, characterized in that: The outer cyclone separator has 12 outer cyclone blades with a blade angle of 40°. The inner hub diameter of the outer cyclone separator is equal to the outer diameter of the gas storage chamber. The swirling air flowing through the outer cyclone separator accounts for 60%-67% of the total incoming air volume.

3. The diffusion-type combustion chamber head injection structure according to claim 1, characterized in that: The axial length of the transition section exceeds 1 / 2 of the axial length of the inner hub of the outer cyclone separator, and is used to adjust the tangential momentum of the swirling air.

4. The diffusion-type combustion chamber head injection structure according to claim 1, characterized in that: The outer diameter of the inner cyclone is equal to the inner diameter of the gas storage chamber. The non-cyclone orifice on it is a small circular orifice with a flow area to blockage area ratio of 1 / 5 to 2 / 5. The amount of non-cyclone air accounts for 6.5% to 10% of the total incoming air volume.

5. The diffusion-type combustion chamber head injection structure according to claim 1, characterized in that: The inner cyclone has two rings of circular cooling holes on its converging wall surface, and the axial direction of the cooling holes is parallel to the axial direction of the outer cyclone.

6. The diffusion-type combustion chamber head injection structure according to claim 1, characterized in that: The hydrogen fuel delivery system consists of four axisymmetric gas delivery pipes, which are used to uniformly deliver hydrogen to the storage chamber.

7. The diffusion-type combustion chamber head injection structure according to claim 1, characterized in that: The diameter of the injection outlet orifice of the hydrogen fuel delivery device is 0.5 mm, and it is evenly arranged in two rings around the circumference with a radial distance of 1 mm between the rings. The radial distance between the inner ring and the central axis of the inner cyclone is 6.5 mm.

8. The diffusion-type combustion chamber head injection structure according to claim 1, characterized in that: The effective flow area of ​​the hollow annular cavity of the hydrogen fuel delivery unit's gas storage chamber is equal to the geometric area of ​​the inner hub of the inner cyclone separator, in order to ensure the proportion of non-swirling air volume.

9. The diffusion-type combustion chamber head injection structure according to claim 1, characterized in that: The outer cyclone, inner cyclone, and fuel conveyor are designed as an integrated unit or mechanically connected.

10. The diffusion-type combustion chamber head injection structure according to claim 1, characterized in that: The non-vortex orifices are arranged in 5 rings at equal radial intervals, with the number of orifices in each ring being 1, 6, 12, 24, and 40 respectively, and the radial distance between the rings being 1.1 mm.

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