Combustion chamber and head thereof

Abstract

A combustion chamber head with a nozzle satisfying hydrogen combustion characteristics, which helps stable and safe combustion of hydrogen fuel and reduces the risk of combustion chamber backfire and ablation. A combustion chamber comprising the aforementioned head can provide zero-carbon emission and low-pollution combustion. The combustion chamber head comprises a nozzle for delivering hydrogen fuel; and a first air passage adjacent to the nozzle; the nozzle comprises a fuel passage for delivering hydrogen combustion fuel; a fuel injection hole in communication with the fuel passage for injecting the hydrogen fuel; a second air passage for delivering air; and an air injection hole in communication with the second air passage for injecting air; the injection direction of the fuel injection hole and the injection direction of the air injection hole are arranged to intersect with the first air passage, and the air injection hole is located on the downstream side of the fuel injection hole.

Description

TECHNICAL FIELD

[0001] The present application relates to a combustion chamber and a head thereof, in particular to a combustion chamber and a head thereof suitable for an aero-engine or a gas turbine or a turbine engine. BACKGROUND

[0002] The increasing environmental awareness makes the reduction of pollutant emissions in the combustion process one of the main challenges in the development of aero-engines and gas turbines. In order to achieve lower NOx emissions while not increasing the concentration of carbon monoxide and unburned hydrocarbons in the exhaust gas, low-emission combustion forms such as lean premixed pre-vaporization and rich quenching lean combustion have been widely researched and applied in gas turbines and aero-engines. However, the exhaust emissions based on hydrocarbon fuels always contain CO2, which cannot meet the requirements of low-carbon combustion. Recently, the combustion organization form based on sustainable fuels and other fuels has been widely researched in aero-engine combustion chambers, the main purpose of which is to further reduce carbon emissions while reducing traditional pollutant emissions (such as NOx).

[0003] Hydrogen combustion, as one of the most environmentally friendly combustion organization methods, has the potential to be a low-carbon fuel with no carbon emissions and other combustion pollution problems. However, hydrogen combustion also has problems such as storage difficulty, high transportation cost per unit volume, too fast combustion speed, and high flame temperature, which brings challenges to how to reasonably organize combustion in the combustion chamber of an aero-engine and a gas turbine. Direct hydrogen combustion in a combustion chamber of an aero-engine and a gas turbine based on traditional kerosene combustion has problems such as difficult hydrogen fuel injection arrangement, high flame temperature, easy backfire, and ablation. Therefore, it is necessary to develop a new hydrogen fuel nozzle assembly to adapt to the characteristics of hydrogen combustion. SUMMARY

[0004] An object of the present application is to provide a combustion chamber head having a nozzle that meets the characteristics of hydrogen combustion, which helps stable and safe combustion of hydrogen fuel and reduces the risk of backfire and ablation of the combustion chamber.

[0005] Another object of the present application is to provide a combustion chamber that can provide zero-carbon emission and low-pollution combustion.

[0006] According to an aspect of the present application, a combustion chamber head includes a nozzle for delivering hydrogen fuel; and a first air passage adjacent to the nozzle; wherein the nozzle includes a fuel passage for delivering hydrogen combustion fuel; a fuel injection hole communicating with the fuel passage for injecting the hydrogen fuel; a second air passage for delivering air; and an air injection hole communicating with the second air passage for injecting air; the injection direction of the fuel injection hole and the injection direction of the air injection hole are arranged to intersect the first air passage, and the air injection hole is located on the downstream side of the fuel injection hole.

[0007] In an embodiment, the nozzle further comprises a bluff body surface facing the flame region, and a cooling hole passing through the bluff body surface and communicating with the second air passage.

[0008] In an embodiment, one of the first air passages is arranged corresponding to one of the fuel injection holes, and one or more of the air injection holes is arranged corresponding to one of the fuel injection holes.

[0009] In an embodiment, the combustion chamber head comprises a plurality of annular bosses, and a plurality of the nozzles are arranged in an array along the entire circumference on each annular boss, the fuel injection holes and the air injection holes are arranged on the radially outer side and / or the radially inner side of the annular boss respectively.

[0010] In an embodiment, an air baffle is arranged between two of the annular bosses, and the air baffle provides a plurality of the first air passages.

[0011] In an embodiment, the combustion chamber head comprises four annular combustion regions arranged at different radial positions around the center of the combustion chamber head, each annular combustion region comprises the fuel injection holes arranged on the radially opposite sides of two adjacent annular bosses, the fuel injection holes of the outermost annular combustion region and the innermost annular combustion region are more in number and smaller in diameter than the fuel injection holes of the two middle annular combustion regions.

[0012] In an embodiment, the distance between the fuel injection holes and the bluff body surface is configured to meet the adjustment parameters of the combustion chamber operating condition.

[0013] In an embodiment, the diameter and number of the fuel injection holes are configured to meet the adjustment parameters of the combustion chamber operating condition.

[0014] In an embodiment, the position and number of the air injection holes are configured to meet the adjustment parameters of the combustion flame stability.

[0015] A combustion chamber comprising an annular combustion chamber outer wall surface, an annular combustion chamber inner wall surface, and a combustion chamber head arranged on the upstream side of the combustion chamber outer wall surface and the combustion chamber inner wall surface, the combustion chamber head adopts any of the combustion chamber heads.

[0016] According to the embodiment of the present application, the hydrogen fuel is injected transversely into the air flow, so that the hydrogen fuel is burned rapidly, and after the hydrogen fuel is injected transversely into the air flow at high speed, the air is mixed rapidly and then burned stably; a plurality of air injection holes are arranged downstream of the fuel injection hole to mix the air, so as to prevent the flame from adhering to the wall boundary layer and reduce the risk of backfire and ablation. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above described and other features, properties, and advantages of the present application will become more apparent by reference to the following description of embodiments of the present application, taken in conjunction with the accompanying drawings in which:

[0018] Figure 1 is a schematic view of a combustion chamber according to an embodiment of the present application;

[0019] Figure 2 is a partial schematic view of a combustion chamber head;

[0020] Figure 3 is a partial cross-sectional view of a combustion chamber head taken along an axial cross-section;

[0021] Figure 4 is a schematic view of an air injection hole arrangement;

[0022] Figure 5 is a corresponding Figure 1 right side view of the combustion chamber shown. DETAILED DESCRIPTION

[0023] Reference will now be made in detail to embodiments of the present application, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the present application, not limitation of the present application. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the scope or spirit of the present application. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present application covers modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

[0024] As used herein, the terms "first", "second", and "third" can be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.

[0025] The terms "upstream" and "downstream" refer to the relative direction with respect to fluid flow in a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction to which the fluid flows.

[0026] As Figure 1 shown, the combustion chamber includes a combustion chamber head 40, a combustion chamber outer wall surface 6, a combustion chamber inner wall surface 5, and is disposed between a combustion chamber outer casing 2 and a combustion chamber inner casing 3. Figure 1 shown is a radial cross-section of a ring structure over a 360° range, for example, a cross-section in the 12 o'clock direction. Hydrogen fuel passes through a fuel pipe 8, through a fuel distribution pipe 9, and into the combustion chamber head. "Hydrogen fuel" includes pure hydrogen fuel or hydrogen-rich fuel, and also includes other fuels having combustion properties similar to hydrogen.

[0027] Air 10 from the compressor, through the diffuser 1 and its divergent section 7, is divided into three streams on the cap 4 with the perforated plate. The cap 4 includes a perforated plate that has the function of straightening and separating the air flow. Air 12 flows through the combustion chamber outer casing 2 and the combustion chamber outer wall 6, and finally forms the combustion chamber outer wall cooling air 13. Air 11 flows through the combustion chamber inner casing 3 and the combustion chamber inner wall 5, and finally forms the combustion chamber inner wall cooling air 14. Air 27 flows through the combustion chamber head 40, then mixes with the fuel, and then enters the combustion chamber to participate in combustion.

[0028] As shown in Figure 2 and Figure 3 , the combustion chamber head 40 includes a nozzle 31 for delivering hydrogen fuel shown in the middle part of Figure 3 , and also includes a first air passage 32 adjacent to the nozzle 31. The first air passage 32 transmits the air that is straightened and separated by the cap 4 into the combustion chamber head 40 downstream on both sides of the nozzle 31, i.e. on both sides in the radial direction. The nozzle 31 includes a fuel passage 25 for delivering hydrogen combustion fuel, two of which are shown in the figure. The nozzle 31 also includes a fuel injection hole 18 that communicates with the fuel passage 25 for injecting hydrogen fuel, and hydrogen combustion is injected from the fuel injection hole 18 to mix with the incoming air to form a mixed gas. The nozzle 31 also includes a second air passage 30 for delivering air, which is preferably located in the middle of the radial cross-section of the nozzle 31, with the fuel passage 25 on both sides of the second air passage 30. The nozzle 31 also includes an air injection hole 17 that communicates with the second air passage 30 for injecting air. The injection direction of the fuel injection hole 18 and the injection direction of the air injection hole 17 are arranged to intersect the first air passage 32, and the intersection includes a right angle or an angle close to a right angle, with the air injection hole 17 located on the downstream side of the fuel injection hole 18. Hydrogen combustion is injected from the fuel injection hole 18 to form a fuel jet 20. Hydrogen fuel from the fuel distribution pipe 9 enters the fuel passage 25 and is finally injected laterally from the fuel injection hole 18 and mixed with air from the air passage 21. Part of the air 27 is used to form the cooling and mixing air 23 of the head, and the air 23 forms the mixed gas 19 through the air injection hole 17. The lateral injection of hydrogen fuel into the air flow facilitates rapid combustion of hydrogen, and after the high-speed lateral injection of hydrogen fuel into the air flow, the hydrogen fuel is rapidly mixed with the air, and then burns stably on the bluff body surface 5. Arranging one or more air injection holes 17 downstream of the fuel injection hole 18 prevents the flame from adhering to the boundary layer of the wall 26, reducing the risk of backfire.

[0029] Continuing to refer to Figure 3 and Figure 1 , the nozzle 31 also includes a bluff body surface 5 facing the flame area, and a cooling hole 16 that communicates with the second air passage 30 and penetrates through the bluff body surface 5. Arranging multiple cooling holes promotes the flow of cooling air inside or adjacent to the bluff body surface 5, reduces the wall temperature, and improves the service life of the material.

[0030] Figure 2 The plurality of air passages 21 between two bluff bodies 5 are shown. As Figure 2 shown, a first air passage 32 is arranged corresponding to a fuel injection hole 18, and a fuel injection hole 18 is arranged corresponding to an air injection hole 17. Figure 4 The arrangement of fuel injection holes 18 and air injection holes 17 is shown. In arrangement A, one air injection hole 17 is arranged downstream of one fuel injection hole 18. In arrangement B, five air injection holes 17 are arranged downstream of one fuel injection hole 18, and the air injection holes 17 are distributed along an arc with a large curvature. In arrangement C, five air injection holes 17 are arranged downstream of one fuel injection hole 18, and the air injection holes 17 are distributed along an arc with a small curvature.

[0031] As Figures 1 to 3 shown, the combustion chamber head 40 includes five annular bosses 41, and a plurality of nozzles 31 are arranged in an array along the entire circumference on each annular boss 41. The fuel injection holes 18 and the air injection holes 17 are arranged on the radially outer side and / or the radially inner side of the annular boss 41, respectively.

[0032] As Figure 2 shown, an air baffle 24 is arranged between two annular bosses 41, and the air baffle 24 provides a plurality of first air passages 32. The air baffle 24 separates the air 21 into a plurality of air flows, which correspond to the fuel injection holes 18, respectively, and facilitates the sufficient mixing of fuel and air.

[0033] As Figures 1 to 3 , Figure 5 shown, in an embodiment, the combustion chamber head 40 includes four combustion zones R1, R2, R3, R4 arranged at different radial positions around the center of the combustion chamber head 40. Each combustion zone includes fuel injection holes 18 arranged on the radially opposite sides of two adjacent annular bosses 41. The fuel injection holes of the outermost and innermost combustion zones R1, R4 are more in number and smaller in diameter than the fuel injection holes of the two middle combustion zones R2, R3. When only the zones R2 and R3 are working, it is adapted to small working conditions of the combustion chamber. When all the combustion zones R1, R2, R3, R4 are working, it is adapted to large working conditions of the combustion chamber. In other embodiments, by flexibly arranging the number of fuel injection holes 18 and the arrangement of air injection holes 17 and cooling holes 16 in the annular combustion chamber, the combustion characteristics requirements of the combustion chamber under different working conditions can be met, forming a zero-carbon emission and low-pollution combustion chamber.

[0034] In an embodiment, in combination Figure 3The distance between the fuel injection orifice 18 and the blunt surface 5 is configured as an adjustable parameter to adapt to different combustion chamber operating conditions. By adjusting the distance between the fuel injection orifice 18 and the blunt surface 5, and by arranging and combining these distances, different combustion chamber operating conditions can be met, increasing the design flexibility of the combustion chamber head.

[0035] In one embodiment, the diameter and number of fuel injection holes 18 are configured to adapt to different combustion chamber operating conditions. By arranging and combining the diameters of the fuel injection holes 18, or by arranging and combining them with the aforementioned distances, different combustion chamber operating conditions can be met, increasing the design flexibility of the combustion chamber head.

[0036] In one embodiment, the position and number of air injection holes 17 are configured as adjustment parameters for combustion flame stability. By adjusting the position and number of air injection holes 17, the stability of the hydrogen combustion flame is improved, and NOx emissions are reduced.

[0037] In one embodiment, the fuel injection port 18 is located at... Figure 3 The position shown is approximately 5-10 mm above the air baffle 24, with an orifice diameter of 0.3-2 mm. The air injection orifice 17 is approximately 3-5 mm above the fuel injection orifice 18, with an orifice diameter of 0.3-1 mm. The cooling orifice 16 is located on the blunt surface 5, with a diameter of approximately 0.2-2 mm. Air 21, 17, and 16 mix with the hydrogen jet 20 for combustion, and the flame is stabilized on the blunt surface 5. The global stoichiometric ratio of the hydrogen combustion flame is 0.3-0.6.

[0038] Hydrogen from fuel distribution pipe 9 enters fuel passage 25 and is ultimately injected laterally into fuel injection hole 18, mixing with air from air passage 32. A portion of the air 27 is used to form cooling and mixing air 23 at the head. Air 23 passes through air injection hole 17 and cooling hole 16 to form mixed gas 19 and cooling gas 22. Cooling holes 16 are uniformly arranged on the blunt body plane 5, forming a protective gas film on the blunt body wall, reducing the wall temperature and improving material life.

[0039] In one embodiment, different air mixing schemes can be formed by changing the distance between different air injection holes 17 and fuel injection holes 18, as well as the arrangement and combination of multiple fuel injection holes 18, to prevent flame adhesion to the boundary layer at the wall 26. A suitable mixing form is selected according to the combustion chamber operating conditions and combustion chamber geometry to achieve stable, low-pollution combustion. A typical arrangement of air injection holes 17 is as follows: Figure 4 As shown in A, B, and C.

[0040] According to the embodiment of the present application, the hydrogen combustion is organized by the method of transversely injecting hydrogen fuel into air, the mixing degree of fuel and air is improved and the risk of backfire of flame in the boundary layer is reduced by arranging air injection holes downstream of the fuel injection holes. On the other hand, the cooling holes are arranged on the plane of the head body, which effectively reduces the influence of the high temperature area of hydrogen flame on the wall temperature, and forms a safe, low-pollution and zero-carbon emission combustion organization form. Since the hydrogen combustion speed is fast and the flame temperature is high, there are problems such as difficulty in arranging hydrogen fuel injection, high flame temperature, easy backfire and ablation in the direct hydrogen combustion of the traditional swirled combustion organization based on kerosene burner. By providing the aforementioned nozzle that meets the characteristics of hydrogen combustion, the combustion and cooling organization form of the combustion chamber is rearranged, which is helpful for stable and safe combustion of hydrogen fuel and reduces the risk of backfire and ablation of the combustion chamber.

[0041] Although the present application is disclosed with the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, which does not deviate from the technical solutions of the present application, falls within the protection scope defined by the claims of the present application.

Claims

1. A combustion chamber head, characterised in that The nozzle comprises: a fuel passage for delivering hydrogen fuel; and a first air passage adjacent to the nozzle; wherein the nozzle comprises: a fuel passage for delivering hydrogen fuel; a fuel injection hole communicating with the fuel passage for injecting the hydrogen fuel; a second air passage for delivering air; and an air injection hole communicating with the second air passage for injecting air; the injection direction of the fuel injection hole and the injection direction of the air injection hole are arranged to intersect the first air passage, and the air injection hole is located on the downstream side of the fuel injection hole.

2. The combustion chamber head of claim 1, wherein The nozzle further comprises a bluff body surface facing a flame region, and a cooling hole communicating with the second air passage and penetrating through the bluff body surface.

3. The combustion chamber head of claim 1 or 2, wherein One of the first air passages is arranged corresponding to one of the fuel injection holes, and one of the fuel injection holes is arranged corresponding to one or more of the air injection holes.

4. The combustion chamber head of claim 1 or 2, wherein The combustion chamber head comprises a plurality of annular bosses, and a plurality of the nozzles are arranged in an array on each annular boss along the entire circumference, and the fuel injection holes and the air injection holes are arranged on the radially outer side and / or the radially inner side of the annular boss, respectively.

5. The combustion chamber head of claim 4, wherein An air baffle is arranged between two of the annular bosses, and the air baffle provides a plurality of the first air passages.

6. The combustion chamber head of claim 4, wherein The combustion chamber head comprises four annular combustion regions arranged at different radial positions around the center of the combustion chamber head, and each annular combustion region comprises the fuel injection holes arranged on the radially opposite sides of two adjacent annular bosses facing each other, and the fuel injection holes of the outermost annular combustion region and the innermost annular combustion region are more in number and smaller in diameter than the fuel injection holes of the two intermediate annular combustion regions.

7. The combustion chamber head of claim 2 wherein, The distance between the fuel injection holes and the bluff body surface is configured to meet the adjustment parameters of the combustion chamber operating conditions.

8. The combustion chamber head of claim 1 or 2, wherein The number and diameter of the fuel injection holes are configured to meet the adjustment parameters of the combustion chamber operating conditions.

9. The combustion chamber head of claim 1 or 2, wherein The position and number of the air injection holes are configured to meet the adjustment parameters of the combustion flame stability.

10. A combustor comprising an annular combustor outer wall surface, an annular combustor inner wall surface, and a combustor head disposed upstream of the combustor outer wall surface and the combustor inner wall surface, characterized by, The combustion chamber head adopts the combustion chamber head according to any one of claims 1 to 9.

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