Combustor

Abstract

To provide a combustor capable of efficiently diffusing fuel into a combustion chamber. [Solution] A combustor according to one embodiment includes a liner having a cylindrical outer wall, a cylindrical inner wall opposite the outer wall, and an annular end wall connecting the outer wall and the inner wall, a supply hole that supplies fuel to a combustion chamber between the outer wall and the inner wall, and a porous injector that is provided at the outlet of the supply hole in the combustion chamber and injects fuel supplied through the supply hole into the combustion chamber.

Description

[Technical Field]

[0001] The present invention relates to a combustor for burning fuel. [Background technology]

[0002] Combustors having a combustion chamber for burning fuel are used in various fields such as gas turbines. In this type of combustor, there is a demand for an improvement in the structure for supplying fuel to the combustion chamber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 1,191,1754 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a combustor that can effectively diffuse fuel into a combustion chamber. [Means for solving the problem]

[0005] A combustor according to one embodiment includes a liner having a cylindrical outer wall, a cylindrical inner wall facing the outer wall, and an annular end wall connecting the outer wall and the inner wall; a supply hole that supplies fuel to a combustion chamber between the outer wall and the inner wall; and a porous injector that is provided at an outlet of the supply hole in the combustion chamber and injects the fuel supplied through the supply hole into the combustion chamber.

[0006] For example, the injector has a distribution space connected to the supply hole, and a plurality of small holes having a cross-sectional area smaller than that of the distribution space and connecting the distribution space to the outer surface of the injector.

[0007] In this case, the distribution space may have a first portion connected to the supply hole, and a plurality of second portions extending from the first portion toward the outer surface of the injector.

[0008] For example, the supply hole and the injector are provided in the end wall. In this case, the combustor may further include a fuel pipe that is provided on an outer surface of the end wall and that is connected to the supply hole.

[0009] For example, the liner may have a plurality of constrictions that reduce the distance between the outer wall and the inner wall.

[0010] In one example, the injector is annular. In this case, the width of the injector may be constant around the entire circumference. Alternatively, the width of the injector may vary depending on the distance from the supply hole. In another example, the injector may be hemispherical.

[0011] The combustor may include a plurality of the supply holes and a plurality of the injectors provided corresponding to the plurality of supply holes, respectively. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a combustor that can efficiently diffuse fuel into a combustion chamber. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic perspective view of a combustor according to a first embodiment. [Figure 2] FIG. 2 is a schematic perspective view of the combustor according to the first embodiment, seen from a direction different from that in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view of the combustor according to the first embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an injector and an end wall of the combustor according to the first embodiment. [Figure 5]FIG. 5 is a schematic cross-sectional view showing an example of a configuration applicable to the injector and end wall according to the first embodiment. [Figure 6] FIG. 6 is a schematic cross-sectional view showing another example of a configuration applicable to the injector and end wall. [Figure 7] FIG. 7 is a schematic cross-sectional view of the vicinity of the injector according to the first embodiment. [Figure 8] FIG. 8 is another schematic cross-sectional view of the vicinity of the injector according to the first embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view showing an injector and an end wall of a combustor according to the second embodiment. [Figure 10] FIG. 10 is a schematic cross-sectional view of the vicinity of an injector according to the second embodiment. [Figure 11] FIG. 11 is a perspective view showing the inside of the injector according to the second embodiment. [Figure 12] FIG. 12 is a schematic cross-sectional view showing an injector and an end wall of a combustor according to a third embodiment. [Figure 13] FIG. 13 is a schematic perspective view of an injector according to the third embodiment. [Figure 14] FIG. 14 is a perspective view showing the inside of the injector according to the third embodiment. [Figure 15] FIG. 15 is a schematic cross-sectional view of the vicinity of an injector according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Several embodiments of a combustor will be described with reference to the drawings. The combustor disclosed in each embodiment is not particularly limited to a specific application, but as an example, the combustor may be applied to a gas turbine.

[0015] [First embodiment] 1 and 2 are schematic perspective views of a combustor 1. The combustor 1 includes a liner 2 made of a thin metal plate. The liner 2 has an outer wall 21 and an inner wall 22 located inside the outer wall 21. The outer wall 21 and the inner wall 22 are both cylindrical and face each other with a gap between them. Specifically, in this embodiment, the outer wall 21 and the inner wall 22 are cylindrical and centered on the axis AX. In the following description, as shown in FIGS. 1 and 2, an axial direction DX along the axis AX, a radial direction DR centered on the axis AX, and a circumferential direction Dθ centered on the axis AX are defined.

[0016] 1, a plurality of openings 31, 32, and 33 are provided in the outer wall 21 of the liner 2. A plurality of openings 34 are provided in the inner wall 22 of the liner 2. For example, at least some of these openings 31, 32, 33, and 34 function as air intakes into the combustion chamber.

[0017] The liner 2 has a plurality of throttle portions 41 arranged in the circumferential direction Dθ. From another perspective, the liner 2 has a plurality of widened portions 42 located between adjacent throttle portions 41.

[0018] In the narrowed portion 41, the distance in the radial direction DR between the outer wall 21 and the inner wall 22 is narrower than in the widened portion 42. For example, such narrowed portion 41 is formed by providing a recess in the outer wall 21 facing the inner wall 22 and providing a recess in the inner wall 22 that faces the recess.

[0019] 1, two openings 31, three openings 32, and one mesh-shaped opening 33 are provided for one throttle portion 41. These two openings 31, three openings 32, and opening 33 are aligned in the axial direction DX. Each opening 34 of the inner wall 22 is located closer to the end 22a of the inner wall 22 in the axial direction DX than the recess of the inner wall 22 of each throttle portion 41.

[0020] An end 21a of the outer wall 21 protrudes in the axial direction DX beyond an end 22a of the inner wall 22. Each opening 31 is provided in a portion of the outer wall 21 that protrudes beyond the end 22a of the inner wall 22.

[0021] 2, the liner 2 has an annular end wall 23 that connects the outer wall 21 and the inner wall 22. Both ends of the end wall 23 in the radial direction DR are curved at a predetermined curvature and smoothly connected to the outer wall 21 and the inner wall 22, respectively.

[0022] A fuel pipe 5 is provided on the end wall 23. The fuel pipe 5 has at least one supply hole 51. This supply hole 51 is connected to, for example, an external fuel supply source.

[0023] 2, the fuel pipe 5 has a circular shape centered on the axis AX, but the shape of the fuel pipe 5 is not limited to this example.

[0024] The end wall 23 is provided with a plurality of openings 35 aligned in the circumferential direction Dθ and a plurality of openings 36 aligned in the circumferential direction Dθ. Each opening 35 is located on the outer diameter side of the fuel pipe 5. Each opening 36 is located on the inner diameter side of the fuel pipe 5. These openings 35, 36 can also function as air intakes to the combustion chamber.

[0025] Figure 3 is a schematic cross-sectional view of the combustor 1 along the axis AX. Figure 4 is a schematic cross-sectional view of the combustor 1 showing the injector 7 and the end wall 23.

[0026] The space surrounded by the outer wall 21, inner wall 22, and end wall 23 of the liner 2 corresponds to the combustion chamber 6 for burning fuel. An annular gap 61 is formed between the end 22a of the inner wall 22 and the outer wall 21. Gas generated by combustion in the combustion chamber 6 is discharged to the outside of the liner 2 through this gap 61.

[0027] A porous injector 7 is disposed on the inner surface of the end wall 23. As shown in FIG. 4, in this embodiment, the injector 7 is annular about the axis AX. The injector 7 is located between the openings 35 and 36. The fuel pipe 5 and the injector 7 form a combustion manifold for supplying fuel to the combustion chamber 6.

[0028] The liner 2, fuel pipe 5, and injector 7 can be integrally formed, for example, by metal three-dimensional molding. Alternatively, the liner 2, fuel pipe 5, and injector 7 may be formed separately and then connected by an appropriate means such as welding.

[0029] 5 is a schematic cross-sectional view showing an example of a configuration applicable to the injector 7 and the end wall 23. A distribution space 71 is formed inside the injector 7. The distribution space 71 is, for example, annular as shown in the figure, but is not limited to this example.

[0030] The end wall 23 has a plurality of supply holes 52. An injector 7 is provided at the outlet of each supply hole 52 in the combustion chamber 6. Specifically, each supply hole 52 is connected to a distribution space 71. In the example of FIG. 5, six supply holes 52 are aligned at regular intervals in the circumferential direction Dθ.

[0031] 6 is a schematic cross-sectional view showing another example of a configuration applicable to the injector 7 and the end wall 23. In the example shown in this figure, 12 supply holes 52 are arranged at regular intervals in the circumferential direction Dθ. For example, in each of FIGS. 5 and 6, each supply hole 52 is provided at a position corresponding to the widened portion 42 in the circumferential direction Dθ.

[0032] The number of supply holes 52 is not limited to the examples in Figures 5 and 6. Furthermore, although the shape of supply holes 52 is, for example, a perfect circle, various other shapes such as an oval shape or a slit shape can also be used.

[0033] 7 and 8 are schematic cross-sectional views of the vicinity of the injector 7. The injector 7 has a semicircular ring shape centered on the axis AX. Inside the injector 7, the above-mentioned distribution space 71 is formed.

[0034] The distribution space 71 has a first portion 711 connected to the supply hole 52 and a plurality of second portions 712 extending from the first portion 711 toward the outer surface of the injector 7. For example, the first portion 711 has a semicircular ring shape centered on the axis AX. In the example shown in FIGS. 7 and 8, three second portions 712 extend from the first portion 711. None of the second portions 712 reach the outer surface of the injector 7. The configuration of the distribution space 71 is not limited to that shown in FIGS. 7 and 8. As another example, the distribution space 71 does not need to have the second portions 712.

[0035] For example, the distribution space 71 has the cross-sectional shape shown in Fig. 8 at any position in the circumferential direction Dθ. However, the shape of the distribution space 71 may vary at least partially in the circumferential direction Dθ.

[0036] The injector 7 has a plurality of small holes 72a and a plurality of small holes 72b. These small holes 72a and 72b each have a cross-sectional area smaller than that of the distribution space 71, and connect the distribution space 71 with the outer surface of the injector 7.

[0037] For example, a plurality of small holes 72a extend radially from the first portion 711 and open to the outer surface of the injector 7. The diameter of the small holes 72a increases as they approach the outer surface of the injector 7.

[0038] The multiple small holes 72b are distributed at regular intervals within a cross section of the injector 7 defined by the radial direction DR and the axial direction DX. Each small hole 72b extends in the circumferential direction Dθ and, in one example, has an annular shape centered on the axis AX. For example, the diameter of each small hole 72b is constant at any position in the circumferential direction Dθ.

[0039] 8, some of the small holes 72a are connected to the second portion 712. Similarly, some of the small holes 72b are connected to the second portion 712. Furthermore, each small hole 72a is connected to at least one small hole 72b. In this way, the injector 7 is porous and has a complex flow path formed by the small holes 72a and 72b.

[0040] The configuration of the injector 7 is not limited to that shown in Figures 7 and 8. In addition, the injector 7 can be formed porous with small holes in various other ways.

[0041] During combustion in the combustor 1 configured as above, liquid fuel is supplied to the fuel pipe 5 through the supply hole 51. This fuel is supplied to the injector 7 through the supply hole 52 in the end wall .

[0042] In the injector 7, first, the first portion 711 of the distribution space 71 is filled with fuel, and the fuel is distributed from the first portion 711 to each of the second portions 712. The fuel distributed to each of the second portions 712 is atomized through the flow passages formed by the small holes 72a and 72b, and is injected into the combustion chamber 6.

[0043] At the beginning of combustion, the fuel injected into the combustion chamber 6 is ignited by a predetermined ignition means. After this ignition, the fuel supplied from the injector 7 is combusted in the combustion chamber 6 continuously.

[0044] The gas produced by combustion is ejected in the axial direction DX from the gap 61 shown in Figure 3. The force produced thereby can be used as thrust or power for a device equipped with the combustor 1.

[0045] By using the porous injector 7 as in this embodiment, the fuel can be dispersed well in the combustion chamber 6. Specifically, by using the injector 7, the fuel can be supplied to a wide area of ​​the combustion chamber 6 as a finer spray than fuel injected from a conventional general nozzle. This makes it possible to improve the combustion efficiency of the combustor 1.

[0046] [Second embodiment] A combustor 1 according to the second embodiment will be described. Elements similar to those in the first embodiment will be given the same reference numerals and descriptions thereof will be omitted.

[0047] FIG. 9 is a schematic cross-sectional view showing the injector 7 and the end wall 23 of the combustor 1 according to the second embodiment. In this embodiment, the width of the injector 7 is not constant in the circumferential direction Dθ. Specifically, the injector 7 has a plurality of wide portions 7a and a plurality of narrow portions 7b. Each narrow portion 7b is located between two wide portions 7a adjacent to each other in the circumferential direction Dθ. In the example of FIG. 9, six wide portions 7a and six narrow portions 7b are formed. However, the number of wide portions 7a and narrow portions 7b is not limited to this example.

[0048] The widened portion 7a has a first width W1 at its center in the circumferential direction Dθ. The narrowed portion 7b has a second width W2 at its center in the circumferential direction Dθ that is smaller than the first width W1 (W1>W2). For example, the first width W1 corresponds to the maximum width of the injector 7. The second width W2 corresponds to the minimum width of the injector 7. The width of the injector 7 gradually decreases from the position of the first width W1 to the position of the second width W2.

[0049] The terms "widened portion" and "narrowed portion" are merely terms used to distinguish between wide and narrow portions of the injector 7. As an example, a portion of the injector 7 having a width greater than the average width thereof can be defined as a widened portion, and a portion having a width smaller than the average width as a narrowed portion.

[0050] 10 is a schematic cross-sectional view of the vicinity of the injector 7. In this embodiment, a distribution space 71 is also formed inside the injector 7. The distribution space 71 has a first portion 711 and a plurality of second portions 712. However, the configuration of the distribution space 71 is not limited to this example. As another example, the distribution space 71 does not have to have the second portions 712.

[0051] 10 is taken along a plane that includes the center of the supply hole 52 and is parallel to the radial direction DR and the axial direction DX. At this point, the injector 7 has a first width W1.

[0052] That is, in this embodiment, the width of the injector 7 is large near the supply hole 52 and becomes smaller with increasing distance from the supply hole 52. From another perspective, the width of the injector 7 changes depending on the distance from the supply hole 52 in the circumferential direction Dθ.

[0053] Fig. 11 is a perspective view showing the inside of the injector 7. As also shown in Fig. 10, in the widened portion 7a, three second portions 712 extend from a first portion 711 of the distribution space 71.

[0054] The shape and cross-sectional area of ​​the distribution space 71 may vary depending on the outer shape of the injector 7. In the example of Fig. 11, the extension length of each second portion 712 from the first portion 711 decreases as it approaches the narrow width portion 7b. For example, the shape of the second portion 712 at each position in the circumferential direction Dθ is determined so that the distance from the tip of the second portion 712 to the outer surface of the injector 7 is constant.

[0055] 11, the second portion 712 is not provided in a part of the narrow width portion 7b. That is, the cross-sectional shape of the distribution space 71 changes in the circumferential direction Dθ.

[0056] The fuel also serves to cool the injector 7. When the shape of the injector 7 is constant in the circumferential direction Dθ as in the first embodiment, the flow rate of fuel may decrease at a location away from the supply hole 52. This reduces the cooling efficiency of the injector 7 at a location away from the supply hole 52, and depending on the combustion conditions and the material of the injector 7, the injector 7 may be damaged by the heat of combustion.

[0057] In contrast, the configuration of this embodiment can improve the cooling efficiency of the injector 7 at a position away from the supply hole 52. That is, in this embodiment, the cross-sectional area of ​​the injector 7 at a position away from the supply hole 52 is small. Therefore, even if the flow rate of fuel decreases at a position away from the supply hole 52, the position can be sufficiently cooled.

[0058] Here, the effects of the configuration according to this embodiment have been described with a focus on the cooling of the injector 7 by the fuel, but by changing the shape of the injector 7 in the circumferential direction Dθ, various other effects can be obtained.

[0059] Furthermore, the shape of the injector 7 at each position in the circumferential direction Dθ may be determined not only in relation to the supply hole 52 but also in relation to the shape of the liner 2, such as the throttle portion 41.

[0060] [Third embodiment] A combustor 1 according to a third embodiment will be described. Elements similar to those in the above-described embodiments will be denoted by the same reference numerals, and a description thereof will be omitted.

[0061] 12 is a schematic cross-sectional view showing the injector 7 and the end wall 23 of the combustor 1 according to the third embodiment. In this embodiment, the multiple injectors 7 are arranged at regular intervals in the circumferential direction Dθ.

[0062] Each injector 7 is provided at a position corresponding to a supply hole 52. That is, in the example of Fig. 12, six supply holes 52 are provided in the end wall 23, and one injector 7 is disposed for each of the supply holes 52. Note that the number of supply holes 52 and injectors 7 is not limited to six.

[0063] Fig. 13 is a schematic perspective view of the injector 7. Fig. 14 is a perspective view showing the inside of the injector 7. Fig. 15 is a schematic cross-sectional view of the vicinity of the injector 7.

[0064] In this embodiment, the injector 7 is hemispherical. As in the above-described embodiments, the injector 7 has a plurality of small holes 72a and a plurality of small holes 72b. The small holes 72a extend radially from the first portion 711 and open to the outer surface of the injector 7. The diameter of the small holes 72a increases as they approach the outer surface of the injector 7.

[0065] 15, the small holes 72b are dispersed at regular intervals within a cross section of the injector 7 defined by the radial direction DR and the axial direction DX. For example, each small hole 72b has an annular shape centered on the axis AX52 of the supply hole 52. Annular grooves are formed in the outer surface of the injector 7 shown in FIG. 13 and are spaced apart at the same intervals as the small holes 72b.

[0066] 14 and 15 , the injector 7 has a distribution space 71. The distribution space 71 has a first portion 711 connected to the supply hole 52 and a plurality of second portions 712. However, the configuration of the distribution space 71 is not limited to this example. As another example, the distribution space 71 does not have to have the second portions 712.

[0067] 14, the first portion 711 is hemispherical. Seven second portions 712 extend radially from the first portion 711. Note that the shape of the first portion 711 and the number of second portions 712 are not limited to this example.

[0068] Even when the porous injectors 7 spaced apart from one another are provided for the respective supply holes 52 as in this embodiment, the fuel can be favorably diffused into the combustion chamber 6. Furthermore, if the injectors 7 are hemispherical, the directional dependency of the fuel injection amount can be alleviated. As a result, as in the above-described embodiments, the combustion efficiency of the combustor 1 can be improved.

[0069] In addition to the first to third embodiments described above, the configuration of the combustor can be modified in various ways. For example, in each embodiment, the liner 2 (the outer shell of the combustion chamber) is disclosed as being configured to inject gas generated by combustion through the gap 61. However, the configuration of the liner 2 is not limited to this example, and various shapes can be applied depending on how the gas and heat generated by combustion are utilized. In other words, the elements of the combustor disclosed in each embodiment, particularly the configuration related to the porous injector 7, can be used for fuel injection in various devices, such as various internal combustion engines, burners, or fuel cells, in addition to gas turbines. [Explanation of symbols]

[0070] 1...combustor, 2...liner, 5...fuel piping, 6...combustion chamber, 7...injector, 21...outer wall, 22...inner wall, 23...end wall, 31-36...opening, 41...throttling portion, 52...supply hole, 71...distribution space, 711...first portion, 712...second portion, 72a, 72b...small holes, AX...axis.

Claims

1. a liner having a cylindrical outer wall, a cylindrical inner wall facing the outer wall, and an annular end wall connecting the outer wall and the inner wall; a supply hole provided in the end wall for supplying fuel to a combustion chamber between the outer wall and the inner wall; a porous injector provided at an outlet of the supply hole on the inner surface of the combustion chamber and configured to inject fuel supplied through the supply hole into the combustion chamber; Equipped with The injector a distribution space having a first portion connected to the supply hole and a plurality of second portions extending from the first portion toward an outer surface of the injector but not reaching the outer surface; a plurality of small holes having a cross-sectional area smaller than the distribution space and connecting the second portion with an outer surface of the injector; The combustor has

2. The plurality of small holes are a plurality of first small holes extending radially from the first portion and opening onto the outer surface of the injector; a plurality of second small holes distributed within a cross section of the injector defined axially along the axis of the liner and radially about the axis; Including, The combustor of claim 1 .

3. The diameters of the plurality of first small holes increase as they approach the outer surface of the injector. The combustor of claim 2 .

4. a fuel pipe provided on the outer surface of the end wall and connected to the supply hole; The combustor of claim 1 .

5. The liner has a plurality of constrictions where the distance between the outer wall and the inner wall is narrowed. The combustor of claim 1 .

6. The injector is annular about the axis of the liner. A combustor according to any one of claims 1 to 5.

7. The width of the injector is constant around the entire circumference. The combustor of claim 6 .

8. the width of the injector varies with the distance from the supply hole; The combustor of claim 6 .

9. The injector A widening portion; a narrow width portion adjacent to the wide width portion in a circumferential direction around the axis and having a width smaller than that of the wide width portion; and The distribution space is annular about the axis, The extension length of the second portion from the first portion decreases as the extension length approaches the narrow portion from the wide portion. The combustor of claim 8 .

10. The injector is hemispherical. A combustor according to any one of claims 1 to 5.

11. a plurality of said supply holes; a plurality of the injectors provided for the plurality of supply holes, respectively; Equipped with A combustor according to any one of claims 1 to 5.

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