Weak rotational flow hydrogen fuel nozzle, combustion chamber and head structure of combustion chamber

Abstract

The weak rotational flow hydrogen fuel nozzle comprises a central annular wall body and a peripheral annular wall body, the central annular wall body comprises a hydrogen fuel flow channel located in the wall body and a first injection hole communicated with the hydrogen fuel flow channel, and an inner cavity defined by the central annular wall body forms a first air flow channel; the one or more peripheral annular wall bodies are sequentially arranged on the periphery of the central annular wall body in a surrounding mode in the radial direction, and a second air flow channel is formed by the peripheral annular wall body and an annular cavity defined by the peripheral annular wall body adjacent to the peripheral annular wall body or the central annular wall body. A combustion chamber and a head structure thereof are also provided. The nozzle can adapt to the characteristic of hydrogen combustion, and the problems that tempering and ablation are prone to occurring in hydrogen combustion, the temperature of local flames is high, and combustion oscillation is prone to occurring are solved.

Description

Technical Field

[0001] This invention relates to the field of aircraft engine combustion chambers, and more specifically to the field of hydrogen combustion. Background Technology

[0002] Hydrogen combustion is one of the more environmentally friendly combustion methods currently available. Traditional aviation kerosene-burning aircraft engines and gas turbine combustors cannot directly burn hydrogen; therefore, it is necessary to develop nozzle assemblies suitable for hydrogen fuel to adapt to the characteristics of hydrogen combustion. Summary of the Invention

[0003] One object of the present invention is to provide a weakly swirling hydrogen fuel nozzle.

[0004] The weak swirling hydrogen fuel nozzle for achieving the above objectives includes:

[0005] The central annular wall includes a hydrogen fuel flow channel located inside the wall and a first injection hole communicating with the hydrogen fuel flow channel, and the inner cavity enclosed by the central annular wall forms a first air flow channel;

[0006] One or more peripheral annular walls are arranged radially around the outer periphery of the central annular wall, and the annular cavity defined by the peripheral annular wall and the adjacent peripheral annular wall or the central annular wall forms a second airflow channel.

[0007] In one or more embodiments, the weak swirling hydrogen fuel nozzle includes a plurality of peripheral annular walls, at least a portion of which are provided with hydrogen fuel channels located inside the walls and a second injection hole communicating with the hydrogen fuel channels.

[0008] In one or more embodiments, the orifice axis of the first injection hole is axial, and the orifice axis of the second injection hole is radial.

[0009] In one or more embodiments, the hydrogen fuel nozzle further includes a perforated plate disposed within the first air passage and / or the second air passage.

[0010] In one or more embodiments, the axial ends of the central annular wall or the outer peripheral annular wall are configured to be inclined relative to the axial direction, so that the outlets of the first air passage and / or the second air passage form a constriction or expansion.

[0011] In one or more embodiments, the hydrogen fuel nozzle further includes swirl vanes disposed within the second airflow channel.

[0012] Another object of the present invention is to provide a combustion chamber head structure. In some embodiments, the combustion chamber head structure is provided with a plurality of the aforementioned weak swirling hydrogen fuel nozzles, wherein one weak swirling hydrogen fuel nozzle serves as a pre-combustion stage located at the center, and the remaining weak swirling hydrogen fuel nozzles serve as a main combustion stage located on the outer periphery of the pre-combustion stage. In other embodiments, the combustion chamber head structure is provided with a single weak swirling hydrogen fuel nozzle, wherein the first injection hole and the first air passage serve as part of the pre-combustion stage, and the second injection hole and the second air passage serve as part of the main combustion stage. In still other embodiments, the combustion chamber head structure is provided with a multi-ring annular injection structure, wherein the annular injection structure comprises a plurality of the aforementioned weak swirling hydrogen fuel nozzles distributed circumferentially.

[0013] Another object of the present invention is to provide a combustion chamber comprising one or more of the above-described combustion chamber head structures.

[0014] The aforementioned weak swirling hydrogen fuel nozzle is designed to address the characteristics of hydrogen combustion by directly injecting hydrogen fuel through the injection hole, thereby increasing the fuel injection speed and reducing the risk of hydrogen combustion backfire. By setting up a first air channel and a second air channel with weak swirling characteristics, the mixing degree of hydrogen and air is improved, the flame temperature is reduced, and NOx emissions are reduced. Attached Figure Description

[0015] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0016] Figure 1 This is a schematic diagram of a hydrogen combustion chamber;

[0017] Figure 2 This is a schematic diagram of the first embodiment of a weak swirling hydrogen fuel nozzle;

[0018] Figure 3 This is a schematic diagram of a second embodiment of a weak swirling hydrogen fuel nozzle;

[0019] Figure 4 This is a schematic diagram of a third embodiment of a weak swirling hydrogen fuel nozzle;

[0020] Figures 5A-5B This is a schematic diagram of an array of weakly swirling hydrogen fuel nozzles;

[0021] Figure 6 This is a partial schematic diagram of a multi-ringed jet structure.

[0022] Symbol marking explanation

[0023] 1. Diffuser

[0024] 2. Hat

[0025] 3' Hydrogen fuel nozzle

[0026] 4. Fuel pipe

[0027] 5 Flame Tubes

[0028] 6. Air

[0029] 7. High-temperature gas

[0030] 8 First airflow channel

[0031] 9 Second airflow channel

[0032] 10 swirl blades

[0033] 11 Hydrogen fuel flow channel

[0034] 12 First injection hole

[0035] 13. Perforated Plate

[0036] 14 Axial end

[0037] 16 Second injection hole

[0038] 22 Exit Plane

[0039] 100 Central annular wall

[0040] 101 Inner cavity

[0041] 140 Exports

[0042] 200 Peripheral annular wall

[0043] 201 Circular cavity

[0044] 301 Pre-combustion Grade

[0045] 302 Main Combustion Grade Detailed Implementation

[0046] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0047] It should be noted that these and other accompanying drawings are merely examples and are not drawn to scale, and should not be construed as limiting the scope of protection of the present invention.

[0048] To achieve lower NOx emissions without increasing the concentration of carbon dioxide and unburned hydrocarbons in the exhaust gas, low-emission combustion methods such as lean fuel premixing and pre-evaporation, and rich fuel quenching and lean fuel combustion have been widely studied and applied in gas turbines and aero engines. However, exhaust emissions from hydrocarbon fuels always contain carbon dioxide. Therefore, combustion organization methods based on sustainable fuels and other zero-carbon fuels have emerged to further reduce carbon emissions while reducing traditional pollutant emissions (such as NOx).

[0049] Hydrogen combustion is one of the more environmentally friendly combustion methods, producing no carbon emissions or other combustion pollutants such as NVPM. However, hydrogen combustion suffers from problems such as excessively fast combustion speed, high flame temperature, and high NOx emissions. In aircraft engines and gas turbine combustors based on traditional aviation kerosene combustion, conventional aviation kerosene swirl combustors typically employ strong swirl and multi-stage swirlers, using a large recirculation zone to stabilize the flame. Due to the rapid combustion speed and high flame temperature of hydrogen, directly performing hydrogen combustion without altering the flow field presents challenges such as difficulties in hydrogen fuel injection arrangement, a high susceptibility to backfire and ablation, locally high flame temperatures, and a tendency for combustion oscillations.

[0050] To address the aforementioned issues, this disclosure proposes a weak swirling hydrogen fuel nozzle, which, based on the characteristics of hydrogen combustion, solves problems such as easy backfire and ablation, high local flame temperature, and easy combustion oscillation in hydrogen combustion without changing the flow field.

[0051] Figure 1 A schematic diagram of a combustion chamber with a weakly swirling hydrogen fuel nozzle is shown. Air 6 from the compressor passes through diffuser 1, and part of it passes through cap 2 before entering the hydrogen fuel nozzle 3 in the combustion chamber to directly participate in combustion. The other part of the air enters the wall of the flame tube 5 as cooling air. Hydrogen enters the hydrogen fuel nozzle 3 through fuel pipe 4. The combustion products mix with the cooling air and then enter the turbine as high-temperature gas 7.

[0052] Hydrogen fuel nozzle 3 features direct injection and weak swirling characteristics, combined with Figures 2 to 4 It is understood that the weak swirling hydrogen fuel nozzle includes a central annular wall 100 and one or more peripheral annular walls 200.

[0053] The central annular wall 100 includes a hydrogen fuel flow channel 11 located inside the wall and a first injection hole 12 communicating with the hydrogen fuel flow channel. The inner cavity 101 enclosed by the central annular wall 100 forms a first air flow channel 8. The hydrogen fuel flow channel 11 is connected to the fuel pipe 4.

[0054] One or more peripheral annular walls 200 are arranged radially around the outer periphery of the central annular wall 100. The annular cavity 201 defined by the peripheral annular wall 200 and its adjacent peripheral annular wall 200 or the peripheral annular wall 200 and its adjacent central annular wall 100 forms a second airflow channel 9.

[0055] Figure 2 and Figure 3 The diagram shows a nozzle structure with an outer annular wall 200, including a first air channel 8 and a second air channel 9. Hydrogen fuel, after passing through the fuel channel 11, is directly injected into the first injection hole 12 and mixed with air. This direct injection method for hydrogen increases the fuel injection velocity and reduces the risk of backfire.

[0056] In some embodiments, the hydrogen fuel nozzle further includes swirl vanes disposed within a second air channel 9, wherein the first air channel 8 is undisturbed, and the second air channel 9 forms a weakly swirling airflow. Furthermore, the first injection hole 12 is configured to inject directly along the axial direction, forming a undisturbed central airflow, reducing the velocity in the central recirculation zone, and lowering the risk of backfire.

[0057] It is also possible to set such as in the first airflow channel 8 Figure 3 The perforated plate 13 shown can further distribute the air distribution in the flow channels 8 and 9, while reducing the pulsation of the incoming air velocity. Combined with direct hydrogen fuel injection, it can meet the requirements of low emissions and low backfire risk, and suppress oscillating combustion.

[0058] Preferably, the hydrogen fuel nozzle further includes swirl vanes 10 disposed within the second airflow channel 9.

[0059] To enhance the weak swirling effect, the angle of the swirling blades is preferably 20-40 degrees, the diameter of the first injection hole 12 is preferably 0.5-2 mm, and the distance between the injection hole and the nozzle outlet plane 22 is preferably 2-6 mm.

[0060] By adjusting the air distribution in the first air channel 8 and the second air channel 9, the number and diameter of the first injection holes 12, and the distance from the first injection holes 12 to the nozzle outlet plane 22, the risk of hydrogen combustion backfire is reduced, the mixing degree of hydrogen and air is improved, the uniformity of combustion temperature is increased, and NOx emissions are reduced.

[0061] Figure 4 A nozzle structure with multiple peripheral annular walls 200 is shown. At least a portion of the peripheral annular walls 200 are also provided with hydrogen fuel channels 11 located inside the walls, and a second injection hole 16 communicating with the hydrogen fuel channels 11.

[0062] exist Figure 4In the embodiment shown, the hole axis of the first injection hole 12 is axial, and the hole axis of the second injection hole 16 is radial. Air enters from the first air channel 8 and the second air channel 9.

[0063] In some embodiments, the axial ends 14 of the central annular wall 100 or the outer peripheral annular wall 200 are inclined relative to the axial direction so that the outlets 140 of the first air passage 8 and / or the second air passage 9 form a constriction or expansion.

[0064] The constricted nozzle structure can increase the injection velocity of hydrogen and air mixture, further reduce the risk of backfire, improve the degree of hydrogen and air mixing, improve the uniformity of combustion temperature, and reduce NOx; the flared nozzle structure can improve the flame distribution after different nozzles are arranged in space, reduce the overall flame temperature and the risk of combustion oscillation, and reduce NOx emissions.

[0065] In this structure, a single weakly swirling hydrogen fuel nozzle can also form a combustion chamber head structure with a main combustion stage and a pre-combustion stage. For example... Figure 4 As shown, a nozzle for direct hydrogen injection with weak swirling flow is arranged at the center of the combustion chamber head as the pre-combustion stage 301 to improve the adaptability of ignition conditions. At the same time, a transverse hydrogen injection nozzle is arranged in a ring as the main combustion stage 302 to further improve the temperature uniformity under large operating conditions and reduce NOx emissions.

[0066] For example Figure 2 and Figure 3 The weakly swirling hydrogen fuel nozzle shown has a single-layer outer annular wall. Multiple weakly swirling hydrogen fuel nozzles can also form a pre-combustion stage and a main combustion stage structure, such as... Figures 5A-5B The combustion chamber head structure is shown. By arranging hydrogen nozzles in an array, different hydrogen nozzles can be combined individually to form different combustion chamber configurations. For example... Figure 2 The nozzle 3 shown is a pre-combustion stage. Figure 3 The nozzle 3' shown is used as the main combustion stage; or Figure 2 The nozzle 3 shown is the main combustion stage. Figure 3 The nozzle 3' shown is used as a pre-combustion stage; or Figure 2 The nozzle 3 shown serves as both the pre-combustion stage and the main combustion stage; or Figure 3 The nozzle 3' shown serves as both the main combustion stage and the pre-combustion stage.

[0067] Figure 5 shows the combustion chamber head structure with an annular injection structure. The head includes multiple annular injection structures, each annular injection structure including multiple circumferentially distributed weak swirling hydrogen fuel nozzles. According to the combustion chamber power and thrust requirements of different engines, different hydrogen nozzle structures and different numbers of hydrogen nozzles are arranged and combined to form a variety of array annular arrangement patterns.

[0068] Based on the description of the combustion chamber head structure above, it can be understood that a combustion chamber including the above structure can be constructed, and the different combustion chamber head structures described above can be combined within the combustion chamber. For example, for high-power or high-thrust engines, a combination of structures such as... Figure 4 The central hierarchy shown and Figure 6 The annular radial staged combustion chamber is shown. For low-power or low-thrust engines, a configuration such as... Figures 5A-5B The pre-combustion stage and main combustion stage structures are shown.

[0069] Furthermore, by adjusting the number, diameter, and height of the hydrogen injection holes, different hydrogen mixing levels and injection speeds can be achieved to meet the design requirements of different combustion chambers.

[0070] The aforementioned weak swirling hydrogen fuel nozzle design for a distributed hydrogen combustion chamber offers the following advantages:

[0071] By designing a weak swirling airflow channel and a direct injection nozzle, it is helpful to reduce the intensity of the central recirculation zone, increase the fuel injection speed, and reduce the risk of combustion chamber backfire and ablation.

[0072] Simultaneously, the design of a weak swirling airflow field can improve the mixing degree of hydrogen and air, reduce flame temperature non-uniformity, and reduce NOx emissions;

[0073] The combination of perforated plates and direct hydrogen fuel injection can improve flame stability and reduce the risk of combustion oscillation.

[0074] It should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0075] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0076] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A weakly swirling hydrogen fuel nozzle, characterized in that, include: The central annular wall includes a hydrogen fuel flow channel located inside the wall and a first injection hole communicating with the hydrogen fuel flow channel, and the inner cavity enclosed by the central annular wall forms a first air flow channel; One or more peripheral annular walls are arranged radially around the outer periphery of the central annular wall, and the annular cavity defined by the peripheral annular wall and the adjacent peripheral annular wall or the central annular wall forms a second airflow channel.

2. The weak swirling hydrogen fuel nozzle as described in claim 1, characterized in that, The weak swirling hydrogen fuel nozzle includes multiple peripheral annular walls, at least a portion of which are provided with hydrogen fuel channels located inside the walls and a second injection hole communicating with the hydrogen fuel channels.

3. The weak swirling hydrogen fuel nozzle as described in claim 2, characterized in that, The first injection hole has an axial direction, and the second injection hole has a radial direction.

4. The weakly swirling hydrogen fuel nozzle as described in claim 1 or 2, characterized in that, The hydrogen fuel nozzle also includes a perforated plate disposed within the first air passage and / or the second air passage.

5. The weak swirling hydrogen fuel nozzle as described in claim 1 or 2, characterized in that, The axial ends of the central annular wall or the outer annular wall are inclined relative to each other in the axial direction, so that the outlets of the first air channel and / or the second air channel form a constriction or expansion.

6. The weak swirling hydrogen fuel nozzle as described in claim 1 or 2, characterized in that, The hydrogen fuel nozzle also includes swirl vanes disposed within the second airflow channel.

7. A combustion chamber head structure, characterized in that, The system includes a plurality of weak swirling hydrogen fuel nozzles as described in any one of claims 1-6, wherein one weak swirling hydrogen fuel nozzle serves as a pre-combustion stage located at the center, and the remaining weak swirling hydrogen fuel nozzles serve as a main combustion stage located on the outer periphery of the pre-combustion stage.

8. A combustion chamber head structure, characterized in that, A weak swirling hydrogen fuel nozzle as described in any one of claims 2-6 is provided, wherein the first injection hole and the first air flow channel are part of the pre-combustion stage, and the second injection hole and the second air flow channel are part of the main combustion stage.

9. A combustion chamber head structure, characterized in that, The device is provided with a multi-ring annular injection structure, wherein the annular injection structure comprises a plurality of circumferentially distributed weak swirling hydrogen fuel nozzles as described in any one of claims 1-6.

10. A combustion chamber, characterized in that, Includes the combustion chamber head structure as described in any one or more of claims 7-9.

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