Combustor and gas turbine

Abstract

The present application provides a combustor including: a tube plate having an upstream side end surface and a downstream side end surface orthogonal to a combustor axis, and formed with an air hole passing through the upstream side end surface and the downstream side end surface; and a fuel injection portion injecting fuel to air flowing in the air hole, the air hole having: a curved flow path curved in a direction orthogonal to the combustor axis toward the downstream side; and a slanted flow path connected to a downstream side of the curved flow path in a continuous manner, extending obliquely to the combustor axis and opening at the downstream side end surface, the fuel injection position of the fuel injection portion being located at a position more downstream than an upstream end of the curved flow path.

Description

TECHNICAL FIELD

[0001] The present application relates to a combustor and a gas turbine.

[0002] This application claims priority from Japanese Patent Application No. 2021-062224 filed on March 31, 2021, and the contents thereof are incorporated herein by reference. BACKGROUND

[0003] For example, Patent Literature 1 discloses a can-annular combustor as an example of a combustor used in a gas turbine.

[0004] The can-annular combustor has a plurality of fuel nozzle portions that inject fuel, and a plurality of air holes that are provided coaxially with the fuel nozzle portions on the downstream side of the fuel nozzle portions. The mixed gas of air and fuel around the fuel injection flows through the air holes and is injected to the downstream side. At this time, by igniting the mixed gas, a plurality of small-scale flames are formed at the end portions on the downstream side of each air hole.

[0005] In each air hole, the upstream side portion is provided as a straight pipe portion that is parallel to the center axis of the combustor, and the downstream side portion is provided as an inclined portion that extends obliquely with respect to the center axis of the combustor. Therefore, a rotational component around the center axis of the combustor is imparted to the mixed gas supplied from the air hole to the downstream side. Thus, the flame can be stably maintained.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent Application Publication No. 2008-111651 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] In the combustor described in Patent Literature 1, the air and the fuel are sharply turned when they reach the inclined portion from the straight pipe portion. Therefore, when the density of the fuel is smaller than that of the air, the fuel is biased toward a part of the inner peripheral surface of the inclined portion due to the difference in specific gravity between the fuel and the air. As a result, the mixing of the fuel and the air is sometimes not sufficiently performed, which can cause backfire.

[0011] The present application has been achieved in order to solve the above problems, and aims to provide a combustor and a gas turbine that can improve flame maintenance while further suppressing backfire.

[0012] MEANS FOR SOLVING THE PROBLEMS

[0013] To solve the above problem, the present application relates to a combustor including: a tube sheet having an upstream side end surface and a downstream side end surface orthogonal to a combustor axis, and having an air hole that penetrates through the upstream side end surface and the downstream side end surface; and a fuel injection portion that injects fuel into air flowing in the air hole, the air hole having: a curved flow path that curves in a direction orthogonal to the combustor axis toward the downstream side; and a slanted flow path that is connected to the downstream side of the curved flow path in a continuous manner, extends obliquely with respect to the combustor axis, and opens at the downstream side end surface, the fuel injection portion injecting the fuel at a fuel injection position located more on the downstream side than an upstream end of the curved flow path.

[0014] The present application relates to a gas turbine including: a compressor that compresses air; the above-described combustor that generates combustion gas by mixing fuel in the air compressed by the compressor and combusting the fuel; and a turbine that is driven by the combustion gas.

[0015] Effects of the Invention

[0016] The combustor and the gas turbine according to the present application can further suppress backfire while improving flame holding property. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic view showing the outline structure of a gas turbine according to a first embodiment of the present application.

[0018] Figure 2 is a longitudinal sectional view showing the outline structure of a combustor according to the first embodiment of the present application.

[0019] Figure 3 is an enlarged view of a main part of the combustor according to the first embodiment of the present application.

[0020] Figure 4 is an enlarged view of a main part of a combustor according to a second embodiment of the present application.

[0021] Figure 5 is an enlarged view of a main part of a combustor according to a modification. Note that the description of the fuel injection portion is omitted.

[0022] Figure 6 is an enlarged view of a main part of a combustor according to a modification. Note that the description of the fuel injection portion is omitted. DETAILED DESCRIPTION

[0023] [First Embodiment]

[0024] Hereinafter, the first embodiment of the present application will be described with reference to Figures 1-3 The first embodiment of the present application will be described in detail. As shown in FIG. 1, a gas turbine 1 according to the first embodiment of the present application includes a compressor 2, a combustor 3, and a turbine 4. Figure 1As shown, the gas turbine 1 of this embodiment includes a compressor 2 for compressing air, a burner 3 for generating combustion gas, and a turbine 4 driven by the combustion gas.

[0025] Multiple burners are arranged circumferentially around the rotating shaft of the gas turbine 1. The burners 3 mix fuel with the air compressed by the compressor 2 and burn it to generate high-temperature and high-pressure combustion gas.

[0026] [Burner]

[0027] The following uses Figure 2 and Figure 3 The structure of burner 3 will be described.

[0028] like Figure 2 As shown, the burner 3 includes a cylinder 10, a shut-off plate 11, a fuel supply pipe 12, a fuel switching section 13, and a burner body 20.

[0029] [Cylinder]

[0030] The cylinder 10 is cylindrical with the burner axis O, which is the central axis of the burner 3, as its center. Multiple air inlet holes 10a, penetrating the cylinder 10 both internally and externally, are formed at circumferential intervals within the cylinder 10.

[0031] [Closed plate]

[0032] The stop plate 11 is positioned to block the rear side of the cylinder 10. Figure 1 The disc-shaped end (left side of the cylinder). The air compressed by the compressor 2 is introduced into the space divided by the cylinder 10 and the stop plate 11 through the air inlet 10a.

[0033] [Fuel supply pipe]

[0034] Fuel supply pipe 12 is the pipe through which fuel flows. Fuel supply pipe 12 extends along the burner axis O, passing back and forth through the stop plate 11. Fuel in fuel supply pipe 12 flows from the rear side to the front side. Figure 1 (On the right side) circulation.

[0035] [Fuel Switching Unit]

[0036] The fuel switching unit 13 switches the type of fuel supplied to the fuel supply pipe 12. In this embodiment, the fuel switching unit 13 is configured to switch between hydrogen and natural gas. For example, the fuel switching unit 13 supplies either hydrogen or natural gas from a hydrogen storage tank or a natural gas tank to the fuel supply pipe 12 from the rear side.

[0037] [Burner body]

[0038] The burner main body 20 is provided to block the front side of the cylinder 10. The burner main body 20 has a mounting portion 21, a tube plate 30, and a fuel injection portion 50.

[0039] [Mounting portion]

[0040] The mounting portion 21 is a cylindrical shape that is centered on the burner axis O and has an outer diameter that is one step smaller than the cylinder 10. A portion of the outer peripheral surface of the mounting portion 21 on the rear side is fixed to the inner peripheral surface of the cylinder 10 over the entire circumference. The mounting portion 21 is provided at a position that does not block the air introduction hole 10a of the cylinder 10.

[0041] [Tube plate]

[0042] The tube plate 30 is a disc shape that is centered on the burner axis O. The rear end of the outer peripheral portion of the tube plate 30 is integrally fixed to the front end of the mounting portion 21 over the entire circumference. The end surface of the tube plate 30 on the rear side is provided as an upstream side end surface 31. The surface of the tube plate 30 on the front side is provided as a downstream side end surface 32. The upstream side end surface 31 and the downstream side end surface 32 are each a planar shape that is orthogonal to the burner axis O and are parallel to each other.

[0043] [Plenum]

[0044] The tube plate 30 has a plenum 33 as a hollow portion on the inner side. Like the outer shape of the tube plate 30, the plenum 33 is a space that is a disc shape. A fuel hole 33a that extends from the inner surface of the plenum 33 to the upstream side end surface 31 over the entire circumference along the burner axis O is formed in the tube plate 30. The front end of the fuel supply pipe 12 is connected to the fuel hole 33a. Thus, the fuel that flows through the fuel supply pipe 12 is introduced into the plenum 33 via the fuel hole 33a. The plenum 33 is filled with the fuel by the supply of the fuel.

[0045] [Tubular wall portion]

[0046] A plurality of tubular wall portions 34 are provided in the tube plate 30 in a manner that extends over the front and rear in the plenum 33. The plurality of tubular wall portions 34 are arranged apart from each other in a direction that is orthogonal to the burner axis O.

[0047] [Air hole]

[0048] A plurality of air holes 40 that pass through the upstream side end surface 31 and the downstream side end surface 32 of the tube plate 30 are formed in the tube plate 30. Each air hole 40 passes through the inside of the tubular wall portion 34. That is, a portion of the flow path of the air hole 40 is formed by the tubular wall portion 34. The plurality of air holes 40 are arranged apart from each other in a direction that is orthogonal to the burner axis O in accordance with the arrangement positions of the tubular wall portions 34.

[0049] The rear side is set as the upstream side, and the front side is set as the downstream side, and air flows in the air hole 40. That is, air introduced into the space partitioned by the cylinder 10 and the closing plate 11 via the air introduction hole 10a flows in the air hole 40 of the tube plate 30 from the rear side toward the front side.

[0050] In detail, as shown in Figure 3 The air hole 40 is configured by connecting the introduction flow path 41, the curved flow path 42, and the inclined flow path 43 in this order from the upstream side toward the downstream side.

[0051] <Introduction flow path>

[0052] The introduction flow path 41 is the most upstream portion of the air hole 40. The introduction flow path 41 has a straight pipe portion 41b extending along a first central axis O1 parallel to the burner axis O. The straight pipe portion 41b extends in a linear shape and with the same inner diameter in the front-rear direction.

[0053] A curved portion 41a is formed between the end portion of the straight pipe portion 41b on the upstream side and the upstream side end surface 31. The curved portion 41a connects between the upstream end of the straight pipe portion 41b and the upstream side end surface 31 in a curved surface. That is, the curved portion 41a opens the introduction flow path 41 at the upstream side end surface 31, and an upstream side opening portion 40a of the air hole 40 is formed.

[0054] The curved portion 41a is provided as a convex curved surface that is reduced in diameter as it goes toward the downstream side. The end portion on the downstream side of the curved portion 41a is smoothly continuous with respect to the end portion on the upstream side of the straight pipe portion 41b.

[0055] <Curved flow path>

[0056] The curved flow path 42 is a portion continuous with the downstream side of the introduction flow path 41, and is a portion that becomes the middle portion of the air hole 40.

[0057] The inner diameter of the curved flow path 42 is set to the same inner diameter as the straight pipe portion 41b of the introduction flow path 41. The curved flow path 42 is connected to the end portion on the downstream side of the straight pipe portion 41b, that is, the end portion on the downstream side of the introduction flow path 41, in a smoothly continuous manner.

[0058] The curved flow path 42 extends in a manner that curves in a direction orthogonal to the burner axis O as it goes toward the downstream side. Due to this, the central axis of the curved flow path 42, that is, a second central axis O2 also curves in a direction orthogonal to the burner axis O as it goes toward the downstream side. In the present embodiment, the second central axis O2 extends around the same center C of a circle with the same radius of curvature from the end portion on the upstream side to the end portion on the downstream side of the curved flow path 42. That is, the curved flow path 42 extends while curving in the same manner from the upstream side to the downstream side.

[0059] [Inclined flow path]

[0060] The inclined flow path 43 extends so as to be inclined at a certain inclination angle with respect to the burner axis O. That is, a central axis of the inclined flow path 43, that is, a third central axis O3 extends in a straight line in a manner that faces toward a direction orthogonal to the burner axis O as it faces toward the downstream side. An inner diameter of the inclined flow path 43 is set to be the same as an inner diameter of the curved flow path 42.

[0061] An end portion of the inclined flow path 43 on the upstream side is connected to an end portion of the curved flow path 42 on the downstream side in a manner that is smoothly continuous. Thereby, the third central axis O3 of the inclined flow path 43 is located on a tangent line in an end portion on the downstream side of the second central axis O2 of the curved flow path 42. An angle of the third central axis O3 of the inclined flow path 43 with respect to the burner axis O is set to be, for example, 10 to 45 degrees, preferably 20 to 40 degrees, and more preferably 25 to 35 degrees. An end portion on the downstream side of the inclined flow path 43 is opened at the downstream end face 32 of the tube plate 30. That is, the end portion on the downstream side of the inclined flow path 43 forms a downstream side opening of the air hole 40. The inclined flow path 43 extends around the burner axis O as viewed in a direction along the burner axis O.

[0062] [Fuel injection portion]

[0063] The fuel injection portion 50 injects fuel into air that flows through the air hole 40. The fuel injection portion 50 of the present embodiment is provided inside the air hole 40, and in the present embodiment, is provided to an inner peripheral surface of the inclined flow path 43 in the air hole 40. The fuel injection portion 50 has a nozzle portion 51 and a plurality of struts 54.

[0064] The nozzle portion 51 extends along the same axis as the third central axis O3. The nozzle portion 51 is in a cylindrical shape that gradually narrows as it faces toward the downstream side. The outer shape of the nozzle portion 51 can be in a streamline shape from the upstream side toward the downstream side. An axial flow path 52 is formed in the nozzle portion 51, which is opened at a front end on the downstream side of the nozzle portion 51 and extends inside the nozzle portion 51 along the third central axis O3. An end portion on the downstream side, that is, a rear end of the nozzle portion 51 is located at a boundary between the curved flow path 42 and the inclined flow path 43.

[0065] The struts 54 fix the nozzle portion 51 to the inner peripheral surface of the inclined flow path 43. The struts 54 are provided a plurality of times at intervals in the peripheral direction of the third central axis O3. An end portion on the outer peripheral side of the strut 54 is fixed to the inner peripheral surface of the inclined flow path 43. An end portion on the inner peripheral side of the strut 54 is fixed to the outer peripheral surface of the nozzle portion 51. A radial flow path 55 that extends in the radial direction of the third central axis O3 is formed inside the strut 54. An end portion on the radially inner side of the radial flow path 55 communicates with the axial flow path 52 inside the nozzle portion 51.

[0066] A cross-sectional shape of the strut 54 that is parallel to the third central axis O3 is preferably in a streamline shape or a blade shape so as not to interfere with the flow of air that flows through the inclined flow path 43.

[0067] Here, the tubular wall portion 34 in the tube plate 30 is formed with a communication hole 34a that penetrates the tubular wall portion 34 in the radial direction along the central axis of the air hole 40. The communication holes 34a are formed in plurality with intervals in the circumferential direction. Each communication hole 34a is connected to and communicates with the radial flow path 55 of the support 54. Thus, the fuel filled in the plenum chamber 33 passes through the communication hole 34a and passes through the radial flow path 55, and flows into the axial flow path 52 in the nozzle portion 51 of the fuel injection portion 50.

[0068] The opening portion of the front end of the nozzle portion 51 of the axial flow path 52 is provided as a front-end injection hole (fuel injection hole) 53 for injecting the fuel flowing in the axial flow path 52 to the downstream side. The front-end injection hole 53 is disposed on the central axis of the air hole 40, and in the present embodiment, in particular, on the central axis of the inclined flow path 43, i.e., the third central axis O3. Thus, the fuel is injected from the front-end injection hole 53 to the downstream side along the central axis of the air hole 40.

[0069] Here, the position at which the fuel injection portion 50 injects the fuel in the direction along the central axis of the air hole 40 is defined as the fuel injection position P. The fuel injection position P of the present embodiment is provided on the straight-line-shaped inclined flow path 43 in the air hole 40.

[0070] [Effects]

[0071] Next, the operation and effects of the combustor 3 according to the present embodiment will be described. The compressed air flows in the air hole 40 in the tube plate 30 of the combustor 3 from the rear side toward the front side, i.e., from the upstream side toward the downstream side. Thus, the fuel is injected to the air flowing in the air hole 40.

[0072] The supply of fuel to the combustor 3 is performed via the fuel switching portion 13. That is, the fuel supply pipe 12 is supplied with hydrogen or natural gas as fuel by the fuel switching portion 13. The fuel is introduced into the plenum chamber 33 of the tube plate 30 via the fuel supply pipe 12. Then, the fuel filled in the plenum chamber 33 is introduced into the fuel injection portion 50 provided in the air hole 40 via the communication hole 34a formed in each tubular wall portion 34. Then, the fuel introduced into the fuel injection portion 50 is injected into the air hole 40 via the front-end injection hole 53 at the front end of the nozzle portion 51.

[0073] The fuel injected into the air hole 40 mixes with the air flowing in the air hole 40 from the upstream side to the downstream side. Thus, a mixture gas is generated. The mixture gas is ejected from the downstream-side opening portion 40b of the air hole 40, and is ignited. Thus, a flame is formed in correspondence with the downstream-side opening portion 40b of each air hole 40.

[0074] Here, when the fuel switching section 13 selects natural gas as the fuel, the flame of the natural gas has low flame retention, and thus it is sometimes difficult to stably retain the flame. In contrast, in the present embodiment, the mixed gas that is ejected from the air hole 40 is ejected toward the downstream side via the inclined flow path 43 of the air hole 40. Thus, the mixed gas is ejected from the air hole 40 in a state in which a rotational component around the burner axis O is imparted thereto. Thereby, the flame based on the mixed gas can be stably retained. That is, the flame retention of the burner 3 can be improved.

[0075] Also, as described above, by imparting a rotational component to the mixed gas, in addition to strengthening the flame retention, an effect of promoting the mixing of air and fuel can be obtained.

[0076] Here, when a flammable fuel such as hydrogen is used, if a rotational component is imparted to the mixed gas within the air hole 40, blowback can occur. Thus, it is difficult to impart a rotational component to the mixed gas within the air hole 40 to promote the mixing of air and fuel.

[0077] In contrast, in the present embodiment, a structure is provided in which a forward flow is not formed within the air hole 40 and a forward flow is formed after the fuel and air exit the air hole 40. That is, the fuel and air can be mixed rapidly after exiting the air hole 40, and thus proper mixing promotion can be achieved while avoiding the risk of blowback. Also, thereby, the NOx that is generated when hydrogen is burned can be reduced. X Thus, the present application can also be applied in a burner that uses only hydrogen as the fuel.

[0078] Also, in the present embodiment, the fuel injection position P of the fuel injection section 50 is provided on the inclined flow path 43. Thus, the fuel that is ejected toward the downstream side within the inclined flow path 43 flows along with the air in a state in which the straightness is maintained. Thereby, the fuel can be inhibited from being ejected in a state in which it is biased toward a circumferential portion of the air hole 40.

[0079] When the fuel injection position P is located more upstream than the curved flow path 42, that is, when the fuel injection position P is located, for example, within the introduction flow path 41 or the upstream side of the tube sheet 30, the fuel and air that flow within the air hole 40 are subjected to a greater centrifugal force in the curved flow path 42. Thus, particularly when the specific gravity difference between the fuel and air is significant, the fuel is biased toward a circumferential portion of the air hole 40 according to the centrifugal force. Particularly when hydrogen is being supplied as the fuel by the fuel switching section 13, the specific gravity of the hydrogen and the air is not the same. Thus, a fuel distribution in which the fuel is biased toward the inside of the curve of the curved flow path 42 is created, and thus the risk of blowback increases.

[0080] In the present embodiment, on the other hand, fuel is injected at a position in the air hole 40 that is more downstream than the curved flow path 42, and thus the air and fuel are not subjected to centrifugal force based on the curved flow path 42. Therefore, the fuel reaches the downstream opening portion 40b of the air hole 40 in a state in which the straightness is maintained. Thus, the generation of backfire can be suppressed.

[0081] Further, the nozzle of the fuel injection portion 50 is a structure that injects fuel toward the downstream side along the central axis of the air hole 40, and thus fuel can be injected in a state in which the fuel is farthest from the inner peripheral surface of the air hole 40. Fuel thus injected flows toward the downstream side in a state in which the straightness is maintained, and thus fuel can be further suppressed from being deflected toward the inner peripheral surface of the air hole 40.

[0082] [2nd Embodiment]

[0083] Next, reference will be made to Figure 4 The 2nd embodiment of the present application will be described. In the 2nd embodiment, the same components as those of the 1st embodiment are denoted by the same reference numerals, and detailed description will be omitted. Figure 4

[0084] The structure of the fuel injection portion 70 of the 2nd embodiment is different from that of the 1st embodiment. The fuel injection portion 70 of the 2nd embodiment has a plurality of inner peripheral injection holes (fuel injection holes) 71.

[0085] The inner peripheral injection holes 71 penetrate the tubular wall portion 34 in the radial direction in a manner that communicates the air chamber 33 with the air hole 40. The inner peripheral injection holes 71 are configured to directly inject fuel in the air hole 40 from the air chamber 33. The plurality of inner peripheral injection holes 71 are formed at a plurality of positions in the circumferential direction with intervals at the same central axis direction position in the air hole 40. The central axis direction position becomes the fuel injection position P in the 2nd embodiment. As with the 1st embodiment, the fuel injection position P of the present embodiment is provided on the inclined flow path 43 in the air hole 40.

[0086] Further, each of the inner peripheral injection holes 71 can be formed at positions that oppose each other in the circumferential direction. That is, the inner peripheral injection holes 71 can be provided as a group of a pair of inner peripheral injection holes 71 formed at positions that oppose each other, and only one group can be formed, or a plurality of groups can be formed.

[0087] According to the above structure, fuel injected from the plurality of fuel injection holes at the same central axis direction position interferes with each other, and thus the fuel easily flows along the central axis of the air hole 40. In particular, when fuel is injected from positions that oppose each other, the radial components of the flow rates of the two flows cancel each other out, and thus a flow along the central axis can be formed. Therefore, as with the 1st embodiment, fuel can be suppressed from being deflected toward a portion of the inner peripheral surface of the air hole 40 and coming into contact.

[0088] [Other Embodiments]​

[0089] The above describes embodiments of the present application, but the present application is not limited to them. The present application can be modified as appropriate without departing from the technical idea of the present application.

[0090] For example, in the embodiment, the fuel injection position P is located on the inclined flow path 43, but is not limited thereto. The fuel injection position P can be the end portion on the upstream side of the inclined flow path 43, or can be inside the curved flow path 42. That is, the fuel injection position P can be located on the downstream side of the end portion on the upstream side of the curved flow path 42.

[0091] As long as the fuel injection position P is located on the straight pipe portion 41b of the introduction flow path 41, fuel with high straightness flows into the curved flow path 42 in accordance with the shape of the straight pipe portion 41b. In this case, a large centrifugal force is applied in the curved flow path 42, and thus a large bias is generated in the circumferential distribution of the fuel. As described above, as long as the fuel is injected halfway through the curved flow path 42, the influence of the centrifugal force based on the curved flow path 42 is suppressed, and thus the bias in the circumferential distribution of the fuel can be suppressed.

[0092] Also, in the embodiment, an example in which the first central axis O1 of the introduction flow path 41 is parallel to the combustor axis O and is perpendicular to the upstream end surface 31 of the tube plate 30 is described. However, this is not limited thereto. For example, as shown in a modification example, Figure 5 the first central axis O1 of the introduction flow path 41 can have a tilt angle with respect to the combustor axis O. The tilt angle of the first central axis O1 with respect to the combustor axis O at this time is smaller than the tilt angle of the third central axis O3 of the inclined flow path 43 with respect to the combustor axis O. Thereby, it is also possible to form the curved flow path 42 centered on the second central axis O2 connecting the first central axis O1 and the second central axis O2. Thus, the purpose of the present application, which determines the fuel injection position P on the premise of a structure having the curved flow path 42 and the inclined flow path 43, is not negated.

[0093] Also, in the embodiment, an example in which the inclined flow path 43 extends in a straight line shape is described, but is not necessarily limited thereto. Instead of the straight line-shaped inclined flow path 43, for example, as shown in a modification example, Figure 6 the inclined flow path 44 having a gentle curvature can be used. The third central axis O3 of the inclined flow path 44 has a curvature radius larger than that of the second central axis O2 that becomes the center of the curved flow path 42. Along with this, the inclined flow path 44 of the modification example is curved to have a smaller curvature than the curved flow path 42. Thereby, the same effects as the embodiment are also obtained.

[0094] [Supplementary note]

[0095] The combustor 3 and the gas turbine 1 described in each embodiment can be understood as follows, for example.

[0096] (1) The combustor 3 according to the first aspect includes: a tube sheet 30 having an upstream side end surface 31 and a downstream side end surface 32 orthogonal to a combustor axis O, and formed with an air hole 40 that penetrates through the upstream side end surface 31 and the downstream side end surface 32; and fuel injection portions 50, 70 that inject fuel into air flowing in the air hole 40, the air hole 40 having: a curved flow path 42 that curves in a direction orthogonal to the combustor axis O toward a downstream side; and inclined flow paths 43, 44 that are connected to the downstream side of the curved flow path 42 in a continuous manner, extend obliquely with respect to the combustor axis O, and open at the downstream side end surface 32, the fuel injection portions 50, 70 injecting the fuel at a fuel injection position P located more on the downstream side than an upstream end of the curved flow path 42.

[0097] According to the above structure, a flow based on the inclined flow paths 43, 44 can be formed on the downstream side of the tube sheet 30, and thus a flame can be stably maintained.

[0098] Further, the fuel injection position is located more on the downstream side than the upstream end of the curved flow path 42, and thus fuel injected from the fuel injection portions 50, 70 can be inhibited from being deflected toward a portion of the circumferential direction of the inclined flow path 43.

[0099] (2) The combustor 3 according to the second aspect can be the combustor 3 according to the first aspect, wherein the fuel injection position P is located more on the downstream side than the upstream end of the inclined flow paths 43, 44.

[0100] The fuel injection position P is located in the inclined flow paths 43, 44, and thus fuel injected from the fuel injection portions 50, 70 flows toward the downstream side in a state in which the fuel maintains straightness. Thus, fuel can be inhibited from being deflected toward a portion of the air hole 40.

[0101] (3) The combustor 3 according to the third aspect can be the combustor 3 according to the first or second aspect, wherein the inclined flow path 43 extends obliquely at a certain oblique angle with respect to the combustor axis O.

[0102] (4) The combustor 3 according to the fourth aspect can be the combustor 3 according to the first or second aspect, wherein the inclined flow path 44 is a flow path that curves to have a smaller curvature than the curved flow path 42.

[0103] (5) The combustor 3 according to the fifth aspect can be the combustor 3 according to any one of the first to fourth aspects, wherein the fuel injection portion 50 has a nozzle portion 51 that injects the fuel toward the downstream side along a central axis of the air hole 40.

[0104] Thus, the fuel flows along the central axis of the air hole 40, and therefore, it is possible to suppress the fuel from contacting a portion of the inner peripheral surface of the air hole 40.

[0105] (6) The combustor 3 according to the sixth aspect can be the combustor 3 according to any one of the first to fourth aspects, wherein the fuel injection portion 70 has a plurality of fuel injection holes arranged at intervals in the circumferential direction of the inner peripheral surface of the air hole 40 at the same central axis direction position in the air hole 40.

[0106] As an example of the fuel injection hole, for example, the inner peripheral injection hole 71 can be cited.

[0107] The fuel injected from the plurality of fuel injection holes at the same central axis direction position interferes with each other, and thus, the fuel easily flows along the central axis of the air hole 40. Therefore, it is possible to suppress the fuel from contacting a portion of the inner peripheral surface of the air hole 40.

[0108] (7) The combustor 3 according to the seventh aspect can be the combustor 3 according to any one of the first to sixth aspects, wherein the air hole 40 further has an introduction flow path 41 that opens at the upstream side end surface 31 and extends in a straight line shape in parallel with the combustor axis O, and a downstream end is connected to the upstream end of the curved flow path 42 in a continuous manner.

[0109] When the introduction flow path 41 is inclined with respect to the combustor axis O, peeling of air is likely to occur at the opening portion on the upstream side end surface 31 of the introduction flow path 41. In the present aspect, the introduction flow path 41 is provided to be parallel with the combustor axis O and orthogonal to the upstream side end surface 31. Therefore, peeling of air in the opening portion can be suppressed.

[0110] (8) The combustor 3 according to the eighth aspect can be the combustor 3 according to the seventh aspect, wherein a first central axis O1 of the introduction flow path 41 is parallel with the combustor axis O and perpendicular with respect to the upstream side end surface 31 of the tube plate 30.

[0111] (9) The combustor 3 according to the ninth aspect can be the combustor according to the seventh aspect, wherein an inclination angle of a first central axis O1 of the introduction flow path 41 with respect to the combustor axis O is smaller than an inclination angle of a third central axis O3 of the inclined flow path 43 with respect to the combustor axis O.

[0112] (10) The combustor 3 according to the tenth aspect can be the combustor 3 according to any one of the first to ninth aspects, further comprising a fuel switching portion 13 that switches the fuel to hydrogen and natural gas.

[0113] Here, when the fuel is natural gas, it is sometimes difficult to stably maintain the flame among other fuels. In the present mode, the mixed gas of air and fuel that is ejected from the inclined flow path 43 toward the downstream side becomes a flow in the direction of the arrow, so even in the case where the fuel is natural gas, it is possible to stably maintain the flame.

[0114] On the other hand, when the fuel is hydrogen, if the inclination angles of the flow paths on the inlet side and the outlet side of the air hole 40 are different, the hydrogen, which has a small specific gravity, is biased toward a portion of the circumference of the outlet of the air hole 40, so this is not preferable. In the present mode, the fuel injection position P is provided at a position that is more on the downstream side than the upstream end of the curved flow path 42, so even in the case where the fuel is hydrogen, it is possible to suppress the biasing of the hydrogen within the air hole 40.

[0115] (11) The gas turbine 1 according to the 11th mode includes: a compressor 2 that compresses air; the combustor 3 according to any one of the 1st to 10th modes that generates a combustion gas by mixing a fuel in the air compressed by the compressor 2 and combusting the same; and a turbine 4 that is driven by the combustion gas.

[0116] According to the gas turbine 1 described above, by providing the mixed gas of the fuel and the air as a flow in the direction of the arrow, it is possible to improve the flame maintaining property while further suppressing the biasing of the fuel within the air hole 40 and suppressing backfire.

[0117] Industrial applicability

[0118] It is possible to provide a combustor and a gas turbine that can improve the flame maintaining property while further suppressing backfire.

[0119] Explanation of symbols

[0120] 1 - gas turbine, 2 - compressor, 3 - combustor, 4 - turbine, 10 - cylinder, 10a - air introduction hole, 11 - closing plate, 12 - fuel supply pipe, 13 - fuel switching portion, 20 - combustor main body, 21 - mounting portion, 30 - tube plate, 31 - upstream side end surface, 32 - downstream side end surface, 33 - plenum, 33a - fuel hole, 34 - tubular wall portion, 34a - communication hole, 40 - air hole, 40a - upstream side opening portion, 40b - downstream side opening portion, 41 - introduction flow path, 41a - curved surface portion, 41b - straight pipe portion, 42 - curved flow path, 43 - inclined flow path, 44 - inclined flow path, 50 - fuel injection portion, 51 - nozzle portion, 52 - axial flow path, 53 - front end injection hole (fuel injection hole), 54 - support member, 55 - radial flow path, 70 - fuel injection portion, 71 - inner peripheral injection hole (fuel injection hole), O - combustor axis, O1 - first central axis, O2 - second central axis, O3 - third central axis, C - center, P - fuel injection position.

Claims

1. A combustor comprising: a tube plate having an upstream side end surface and a downstream side end surface orthogonal to a combustor axis, and formed with an air hole passing through the upstream side end surface and the downstream side end surface; and a fuel injection section injecting fuel into air flowing in the air hole, wherein the air hole has the following structure: a curved flow path curved in a direction orthogonal to the combustor axis toward the downstream side; a lead-in flow path opening at the upstream side end surface and extending in a straight line parallel to the combustor axis, and a downstream end connected to an upstream end of the curved flow path in a continuous manner; and an inclined flow path connected to the downstream side of the curved flow path in a continuous manner, extending obliquely to the combustor axis and opening at the downstream side end surface, wherein a fuel injection position at which the fuel injection section injects the fuel is located more on the downstream side than the upstream end of the curved flow path.

2. The combustor according to claim 1, wherein the fuel injection position is located more on the downstream side than an upstream end of the inclined flow path.

3. The combustor according to claim 1 or 2, wherein the inclined flow path extends obliquely at a certain oblique angle to the combustor axis.

4. The combustor according to claim 1 or 2, wherein the inclined flow path is a flow path curved with a curvature smaller than that of the curved flow path.

5. The combustor according to claim 1 or 2, wherein the fuel injection section has a nozzle section that injects the fuel, and the nozzle section has a fuel injection hole that injects the fuel toward the downstream side along a central axis of the air hole.

6. The combustor according to claim 1 or 2, wherein the fuel injection section has a plurality of fuel injection holes arranged in a circumferential direction on an inner peripheral surface of the air hole at the same central axis direction position in the air hole.

7. The combustor according to claim 1, wherein a first central axis of the lead-in flow path is parallel to the combustor axis and perpendicular to the upstream side end surface of the tube plate.

8. The combustor according to claim 1, wherein an oblique angle of the first central axis of the lead-in flow path to the combustor axis is smaller than an oblique angle of a third central axis of the inclined flow path to the combustor axis.

9. The combustor according to claim 1 or 2, further comprising: a fuel switching section that switches the fuel between hydrogen and natural gas.

10. A gas turbine comprising: a compressor that compresses air; the combustor according to any one of claims 1 to 9 that generates combustion gas by mixing fuel in the air compressed by the compressor and combusting the fuel; and a turbine that is driven by the combustion gas. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Images