Combustion chamber and head thereof

Abstract

A combustion chamber head is provided with a nozzle meeting the hydrogen combustion characteristic, stable and safe combustion of hydrogen fuel is facilitated, and the risk of tempering and ablation of a combustion chamber is reduced. The combustion chamber comprises the head part and can provide zero-carbon-emission low-pollution combustion. The combustion chamber head comprises a nozzle for conveying hydrogen fuel; and a first air passage adjoining the nozzle; the nozzle comprises a fuel channel for conveying hydrogen for combustion; the fuel injection hole is communicated with the fuel channel and is used for injecting the hydrogen fuel; the second air channel is used for conveying air; the air injection hole is communicated with the second air channel and is used for injecting air; an ejection direction of the fuel injection hole and an ejection direction of the air injection hole are disposed so as to intersect the first air passage, and the air injection hole is located on a downstream side of the fuel injection hole.

Description

Technical Field

[0001] The present invention relates to a combustion chamber and a head thereof, and in particular to a combustion chamber and a head thereof suitable for an aircraft engine, a gas turbine or a turbine engine. Background Art

[0002] The increase in environmental awareness has made the reduction of pollutant emissions during the combustion process one of the main challenges in the development of aircraft engines and gas turbines. In order to achieve lower NOx emissions without increasing the concentration of exhaust carbon monoxide and unburned hydrocarbons, low-emission combustion forms such as lean oil premixing preevaporation and rich oil quenching lean oil combustion have been widely studied and applied in gas turbines and aircraft engines. However, the exhaust emissions based on hydrocarbon fuels always contain CO 2 , which cannot meet the requirements of low-carbon combustion. Recently, combustion organization forms based on sustainable fuels and other fuels have been widely studied in aircraft engine combustors, with the main purpose of further reducing carbon emissions while reducing traditional pollutant emissions (such as NOx).

[0003] As one of the most environmentally friendly combustion organization methods, hydrogen combustion has no combustion carbon emissions and other combustion pollution products, and is a low-carbon fuel with great potential. However, hydrogen combustion also has problems such as storage difficulties, high transportation costs per unit volume, too fast combustion speed, and high flame temperature, which brings challenges to how to reasonably organize combustion in the combustion chambers of aircraft engines and gas turbines. Direct hydrogen combustion in aircraft engines and gas turbine burners based on traditional kerosene combustion has problems such as difficulty in hydrogen fuel injection arrangement, high flame temperature, easy flashback and ablation. Therefore, it is necessary to develop a new hydrogen fuel nozzle assembly to adapt to the characteristics of hydrogen combustion. Summary of the invention

[0004] One object of the present invention is to provide a combustion chamber head having a nozzle that meets the characteristics of hydrogen combustion, which helps to ensure stable and safe combustion of hydrogen fuel and reduces the risks of flashback and ablation in the combustion chamber.

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

[0006] According to one aspect of the present invention, a combustion chamber head includes a nozzle for conveying hydrogen fuel; and a first air passage adjacent to the nozzle; wherein the nozzle includes a fuel passage for conveying hydrogen combustion; a fuel injection hole communicating with the fuel passage and for ejecting the hydrogen fuel; a second air passage for conveying air; and an air injection hole communicating with the second air passage and for ejecting air; the ejection direction of the fuel injection hole and the ejection 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.

[0007] In one embodiment, the nozzle further includes a bluff surface facing the flame region, and a cooling hole communicating with the second air passage and penetrating the bluff surface.

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

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

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

[0011] In one embodiment, the combustion chamber head includes four circles of combustion areas arranged at different radial positions around the center of the combustion chamber head, each circle of combustion areas includes the fuel injection holes arranged on the radial sides opposite to each other of two adjacent annular bosses, and the fuel injection holes in the outermost and innermost circles of the combustion areas are more in number and smaller in diameter than the fuel injection holes in the two middle circles of the combustion areas.

[0012] In one embodiment, the distance between the fuel injection hole and the bluff surface is configured to meet the adjustment parameters of the combustion chamber working conditions.

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

[0014] In one embodiment, the positions and quantities of the air injection holes are configured as adjustment parameters for combustion flame stability.

[0015] A combustion chamber comprises 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, wherein the combustion chamber head adopts any of the above-mentioned combustion chamber heads.

[0016] According to an embodiment of the present invention, hydrogen fuel is injected laterally into an air flow to achieve rapid combustion of hydrogen fuel. After the hydrogen fuel is injected laterally into the air flow at high speed, it is quickly mixed with the air and then burns stably. A plurality of air jet holes are arranged downstream of the fuel jet hole for mixing to prevent the flame from adhering to the wall boundary layer and reduce the risk of flashback and ablation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

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

[0019] Figure 2 It is a partial schematic diagram of the combustion chamber head;

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

[0021] Figure 4 is a schematic diagram of the arrangement of the air injection holes;

[0022] Figure 5 It corresponds to 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 invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided to explain the present invention, not to limit the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature illustrated or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present invention is intended to cover these modifications and variations within the scope of the appended claims and their equivalents.

[0024] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of the respective components.

[0025] The terms "upstream" and "downstream" refer to relative directions relative to the flow of a fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing.

[0026] like Figure 1 As shown, the combustion chamber includes a combustion chamber head 40, a combustion chamber outer wall surface 6, and a combustion chamber outer wall surface 5, and the combustion chamber is arranged between the combustion chamber outer casing 2 and the combustion chamber inner casing 3. Figure 1 The content shown is a structure of a ring structure cut along a radial direction within a range of 360°, for example, a structure cut at the 12 o'clock direction. The hydrogen fuel passes through the fuel pipe 8 and the fuel distribution pipe 9 into the head of the combustion chamber. "Hydrogen fuel" includes pure hydrogen fuel or hydrogen-rich fuel, and also includes other fuels with combustion characteristics similar to hydrogen.

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

[0028] like Figure 2 and Figure 3 As shown, the combustion chamber head 40 includes Figure 3 The nozzle 31 for conveying hydrogen fuel shown in the middle part also includes a first air channel 32 adjacent to the nozzle 31. The first air channel 32 transmits air that is rectified and separated by the cap 4 and then enters the combustion chamber head 40 downstream on the left and right sides of the nozzle 31, that is, on both radial sides. The nozzle 31 includes a fuel channel 25 for conveying hydrogen combustion, and two left and right channels are shown in the figure. The nozzle 31 also includes a fuel injection hole 18 that is connected to the fuel channel 25 and is used to spray hydrogen fuel. The hydrogen combustion is sprayed from the fuel injection hole 18 and mixed with the incoming air to form a mixed gas. The nozzle 31 also includes a second air channel 30 for conveying air. The preferred position of the second air channel 30 is in the middle of the radial cross section of the nozzle 31, and the fuel channel 25 is on both radial sides of the second air channel 30. The nozzle 31 also includes an air injection hole 17 that is connected to the second air channel 30 and is used to spray air. The ejection direction of the fuel injection hole 18 and the ejection direction of the air injection hole 17 are arranged to intersect with the first air channel 32, and the intersection includes orthogonal or nearly orthogonal intersection, and the air injection hole 17 is located on the downstream side of the fuel injection hole 18. Hydrogen combustion is ejected from the fuel injection hole 18 to form a fuel jet 20. The hydrogen fuel from the fuel distribution pipe 9 enters the fuel channel 25, and is finally sprayed laterally at the fuel injection hole 18 to mix with the air from the air channel 21. A part of the air 27 is used to form the cooling and mixing air 23 of the head, and the air 23 passes through the air injection hole 17 to form the mixed gas 19. The lateral injection of hydrogen fuel into the air flow is conducive to the rapid combustion of hydrogen. After the hydrogen fuel is laterally injected into the air flow at a high speed, it is quickly mixed with the air and then stably burns on the blunt body surface 5. One or more air injection holes 17 are arranged downstream of the fuel injection hole 18 to prevent the flame from adhering to the boundary layer of the wall 26 and reduce the risk of flashback.

[0029] Continue to refer to Figure 3 and Figure 1 The nozzle 31 also includes a bluff surface 5 facing the flame area, and a cooling hole 16 communicating with the second air passage 30 and penetrating the bluff surface 5. The plurality of cooling holes are provided to promote the flow of cooling airflow inside or around the bluff surface 5, reduce the wall temperature, and increase the service life of the material.

[0030] Figure 2 FIG. 5 shows a plurality of air passages 21 between two bluff surfaces 5. Figure 2 As shown, one first air passage 32 is disposed correspondingly to one fuel injection hole 18 , and one fuel injection hole 18 is disposed correspondingly to one air injection hole 17 . Figure 4 The configuration of the fuel injection holes 18 and the air injection holes 17 is shown. In configuration A, one air injection hole 17 is configured downstream of one fuel injection hole 18. In configuration B, five air injection holes 17 are configured downstream of one fuel injection hole 18, and the air injection holes 17 are distributed along an arc with a larger curvature. In configuration C, five air injection holes 17 are configured downstream of one fuel injection hole 18, and the air injection holes 17 are distributed along an arc with a smaller curvature.

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

[0032] like Figure 2 As shown, an air baffle 24 is disposed between the two annular bosses 41, and the air baffle 24 provides a plurality of first air passages 32. The air baffle 24 divides the air 21 into a plurality of air streams, which respectively correspond to the fuel injection holes 18, so as to facilitate the full mixing of the fuel and the air.

[0033] like Figures 1 to 3 , Figure 5 As shown, in one embodiment, the combustion chamber head 40 includes four circles of combustion areas R1, R2, R3, and R4 arranged at different radial positions around the center of the combustion chamber head 40, and each circle of the combustion area includes fuel injection holes 18 arranged on the radial sides of two adjacent annular bosses 41 opposite to each other. The number of fuel injection holes in the outermost and innermost combustion areas R1 and R4 is larger and the aperture is smaller than that of the fuel injection holes in the middle two circles of the combustion areas R2 and R3. When only areas R2 and R3 are working, it is suitable for small and medium working conditions in the combustion chamber. When all combustion areas R1, R2, R3, and R4 are working, it is suitable for large working conditions in 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 to form a zero-carbon emission and low-pollution combustion chamber.

[0034] In one embodiment, in combination Figure 3The distance between the fuel injection hole 18 and the bluff surface 5 is configured as an adjustment parameter to adapt to different combustion chamber working conditions. By adjusting the distance between the fuel injection hole 18 and the bluff surface 5 and arranging and combining the distances, different combustion chamber working conditions can be met and the design flexibility of the combustion chamber head can be increased.

[0035] In one embodiment, the diameter and number of the fuel injection holes 18 are configured to be adjustment parameters adapted to different combustion chamber operating conditions. By the diameter of the fuel injection holes 18 and the arrangement and combination of the diameters, or the arrangement and combination 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 the air injection holes 17 are configured as adjustment parameters for combustion flame stability. By adjusting the position and number of the 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 hole 18 is located at Figure 3 The position shown is about 5-10mm higher than the air baffle 24, and the aperture is 0.3-2mm. The position of the air injection hole 17 is about 3-5mm higher than the fuel injection hole 18, and the aperture of the air injection hole 17 is 0.3-1m. The cooling hole 16 is located on the bluff surface 5, and the cooling hole diameter is about 0.2-2mm. The air 21, 17 and 16 and the hydrogen jet 20 are mixed and burned, and the flame is stabilized on the bluff plane 5. The global chemical equivalence ratio of the hydrogen combustion flame is 0.3-0.6.

[0038] The hydrogen from the fuel distribution pipe 9 enters the fuel channel 25, and is finally sprayed horizontally at the fuel injection hole 18 to mix with the air from the air channel 32. A part of the air 27 is used to form the cooling and mixing air 23 of the head, and the air 23 passes through the air injection hole 17 and the cooling hole 16 to form the mixed gas 19 and the cooling gas 22. The cooling holes 16 are evenly arranged on the bluff body plane 5 to form a protective gas film on the bluff body wall, reduce the wall temperature, and increase the material life.

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

[0040] According to an embodiment of the present invention, hydrogen combustion is organized by a method of horizontally injecting hydrogen fuel into the air, and at the same time, by arranging an air injection hole downstream of the fuel injection hole, the degree of mixing of fuel and air is improved, and the risk of flame flashback in the boundary layer is reduced. On the other hand, cooling holes are arranged on the blunt body plane of the head to effectively reduce the impact of the high temperature zone of the hydrogen flame on the wall temperature, forming a safe, low-pollution, zero-carbon emission combustion organization. Due to the fast combustion speed of hydrogen and the high flame temperature, kerosene burners based on traditional swirl combustion organizations directly carry out hydrogen combustion, which have problems such as difficulty in hydrogen fuel injection arrangement, high flame temperature, easy flashback and ablation. By providing the aforementioned nozzle that meets the characteristics of hydrogen combustion and rearranging the combustion and cooling organization of the combustion chamber, it is helpful to stably and safely burn hydrogen fuel and reduce the risk of flashback and ablation in the combustion chamber.

[0041] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. Combustion chamber head, characterized in that: include: a nozzle for delivering hydrogen fuel; as well as a first air passage adjacent the nozzle; Wherein, the nozzle comprises: a fuel channel for transporting hydrogen for combustion; a fuel injection hole communicating with the fuel passage and used for injecting the hydrogen fuel; a second air passage for conveying air; and an air injection hole communicating with the second air passage and used for ejecting air; The ejection direction of the fuel injection hole and the ejection direction of the air injection hole are arranged to intersect with the first air passage, and the air injection hole is located on a downstream side of the fuel injection hole.

2. The combustion chamber head according to claim 1, characterized in that The nozzle further includes a bluff surface facing the flame region, and a cooling hole communicating with the second air passage and penetrating the bluff surface.

3. The combustion chamber head according to claim 1 or 2, characterized in that: One of the first air passages is arranged correspondingly to one of the fuel injection holes, and one of the fuel injection holes is arranged correspondingly to one or more of the air injection holes.

4. The combustion chamber head according to claim 1 or 2, characterized in that: The combustion chamber head includes 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 respectively arranged on the radial outer side and / or radial inner side of the annular boss.

5. The combustion chamber head according to claim 4, characterized in that An air baffle is arranged between the two annular bosses, and the air baffle provides a plurality of the first air channels.

6. The combustion chamber head according to claim 4, characterized in that The combustion chamber head includes four circles of combustion areas arranged at different radial positions around the center of the combustion chamber head, each circle of combustion areas includes the fuel injection holes arranged on the radial sides opposite to each other of two adjacent annular bosses, and the fuel injection holes in the outermost and innermost circles of the combustion areas are more in number and smaller in diameter than the fuel injection holes in the two middle circles of the combustion areas.

7. The combustion chamber head according to claim 2, characterized in that The distance between the fuel injection hole and the bluff body surface is configured to meet the adjustment parameters of the combustion chamber working conditions.

8. The combustion chamber head according to claim 1 or 2, characterized in that: The aperture and quantity of the fuel injection holes are configured to meet the adjustment parameters of the combustion chamber working conditions.

9. The combustion chamber head according to claim 1 or 2, characterized in that: The positions and quantity of the air injection holes are configured as adjustment parameters for combustion flame stability.

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

Images