BURNER ARRANGEMENT, GAS TURBINE COMBUSTION CHAMBER AND GAS TURBINE

Abstract

A burner assembly (32) having a plurality of burners (42) for mixing fuel and air, wherein each of the plurality of burners (42) comprises: at least one fuel nozzle (43) for injecting the fuel, and a mixing passage (46) into which the fuel injected from the at least one fuel nozzle (43) and the air are introduced, each of the at least one fuel nozzle (43) comprising a projecting portion (50) projecting upstream of an inlet (48) of the mixing passage (46) in a flow direction of the air, wherein each of the at least one fuel nozzle (43) comprises at least one fuel injection hole (53) formed on a side surface (44) of the projecting portion (50), wherein the plurality of burners (42) comprises a first burner (42a) and a second burner (42b) having the mixing passage (46b) closest to the mixing passage (46a) of the first burner (42a), wherein a passage wall (55) forming the mixing passage (46a) of the first burner (42a) and a passage wall (55) forming the mixing passage (46b) of the second burner (42b) have in common a separating section (58ab) separating the mixing passage (46a) of the first burner (42a) from the mixing passage (46b) of the second burner (42b), wherein, when a cross section of the partition portion (58ab) passing through a center (C1) of the inlet (48) of the mixing passage (46a) of the first burner (42a) and a center (C2) of the inlet (48) of the mixing passage (46b) of the second burner (42b) and along a center axis (O) of the mixing passage (46a) of the first burner (42a) is defined as a first cross section, and wherein the projecting portion (50) projects upstream from a position of an upstream end surface (59) of the partition portion (58ab) in the first cross section in the flow direction of the air, characterized in that an entire upper surface (54) of the projecting portion (50) is streamlined from a convexly curved surface (56).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a burner assembly, a gas turbine combustor, and a gas turbine. BACKGROUND

[0002] As a technique to achieve low NOx levels while maintaining resistance to flashback in fuels with a high risk of flashback (e.g. hydrogen), a large number of independent short flames are formed by a burner arrangement (cluster burner).

[0003] In this technique, by arranging multiple mixing passes for mixing fuel and air to reduce the extent of fuel mixing, high mixing efficiency can be achieved without actively using vortex flow to mix fuel and air.

[0004] Patent Document 1 discloses a burner assembly for preventing flashback while reducing NOx. Each burner of this burner assembly includes a fuel nozzle and a mixing passage into which fuel and air are introduced. The fuel nozzle includes a protruding portion protruding upstream of an inlet of the mixing passage in the air flow direction. Further, a fuel injection hole is formed on a side surface of the protruding portion. The fuel injected from the fuel injection hole enters the inlet of the mixing passage together with air, so that the fuel and air are mixed.

[0005] Patent Document 1 describes that by injecting fuel from the protruding portion protruding upstream of the inlet of the mixing passage in the air flow direction, the fuel and air are effectively mixed to prevent fluctuations in the fuel concentration in the mixing passage and reduce NOx. Furthermore, it is described that since the air enters upstream of the inlet of the mixing passage and downstream of the nozzle injection hole, the increase in the fuel concentration near the passage wall downstream of the fuel injection hole is prevented, so that flashback (backfire) can be prevented.

[0006] Patent Document 2 discloses a fuel nozzle assembly. The assembly includes an outer nozzle body having a first end and a second end, and at least one inner nozzle tube having a first end and a second end. One of the nozzle body and the nozzle tube includes a fuel plenum and a fuel passage extending therefrom, while the other of the nozzle body and the nozzle tube includes a fuel injection hole slidably aligned with the fuel passage to provide a fuel flow path therebetween at a junction between the body and the tube. The nozzle body and the nozzle tube are fixed against relative movement at the first ends of the nozzle body and the nozzle tube, thereby allowing the fuel flow path to close at the junction due to thermal expansion after a flame enters the nozzle tube.

[0007] Patent Document 3 discloses that a monolithic fuel injection head for a fuel nozzle includes a substantially hollow chamber body formed with an upstream end surface, a downstream end surface, and a peripheral wall extending therebetween, and an inner partition plate extending radially outward from a downstream end of the bore and terminating short of the peripheral wall, thereby forming upstream and downstream fuel chambers in the chamber body, which are in fluid communication through a radial gap between the partition plate and the peripheral wall.A plurality of integral premix tubes extend axially through the upstream and downstream fuel chambers in the chamber body and the partition plate, with at least one fuel injection port extending between each of the premix tubes and the upstream fuel chamber, allowing the fuel in the upstream chamber to be introduced into the plurality of premix tubes. The fuel injection head is fabricated by direct metal laser sintering.

[0008] Patent Document 4 discloses a gas turbine combustor including an air passage for supplying air into the interior and a fuel nozzle provided with an injection port for injecting fuel and arranged in the air passage, wherein a turbulence generating device is provided adjacent to the injection port of the fuel nozzle in the air passage.Furthermore, Patent Document 4 discloses a gas turbine combustor including an air passage for supplying air into the interior and a fuel nozzle provided with an injection port for injecting fuel and disposed in the air passage. A diffuser portion is provided in the air passage, and the diffuser portion causes the cross-sectional area of a portion of the air passage located in the vicinity of the injection port to be smaller than that of a downstream portion of the air passage located downstream of the injection port in the airflow direction. This can improve the mixing of fuel and air and prevent combustion vibrations.

[0009] Patent Document 5 discloses a method for reducing self-induced flame oscillations. In a first fluid mass flow flowing through a jet nozzle from a fluid inlet port to a fluid outlet port, a second fluid mass flow is injected at an axial position of the jet nozzle downstream of the fluid inlet port. One fluid mass flow contains air, and the other fluid mass flow contains a fuel. Patent Document 5 also discloses a second method for reducing self-induced flame oscillations. In a first fluid mass flow flowing through a jet nozzle from a fluid inlet port to a fluid outlet port, a second fluid mass flow is injected at a radial position of the jet nozzle with respect to the circumference of the jet nozzle. One fluid mass flow contains air, and the other fluid mass flow contains a fuel. Burners are also provided to ensure the implementation of the method.

[0010] Patent Document 6 discloses a combustor comprising: a casing having an air chamber filled with air; at least one mixing passage forming member forming at least one mixing passage connected to the air chamber on an inlet side and to a combustion chamber on an outlet side, and having an inlet formed on the inlet side of the at least one mixing passage so as to communicate with the air chamber; and at least one fuel nozzle disposed inside the air chamber and having a fuel injection hole disposed upstream of the inlet of the mixing passage forming member for injecting fuel in the downstream direction. Citation listPatent literature Patent Document 1: JP 2019-168 198 A Patent specification 2: DE 10 2009 026 338 A1 Patent specification 3: DE 10 2010 017 623 A1 Patent specification 4: US 2003 / 0 110 774 A1 Patent specification 5: US 2010 / 0 323 309 A1 Patent specification 6: DE 11 2019 000 871 T5 SUMMARYProblems to be solved

[0011] The burner arrangement described in Patent Document 1 still has room for improvement in terms of preventing flashback.

[0012] In view of the foregoing, it is an object of the present disclosure to provide a burner assembly and a gas turbine combustor capable of preventing flashback. Solving the problems

[0013] To achieve the aforementioned object, a burner assembly according to independent claim 1 is provided. Furthermore, a gas turbine combustor according to independent claim 6 and a gas turbine according to independent claim 7 are provided. Advantageous modifications can be found in dependent claims 2 to 5. Beneficial effects

[0014] The present disclosure provides a burner assembly and a gas turbine combustor capable of preventing flashback. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of a configuration of a gas turbine 100 according to one embodiment. Fig. 2 is a cross-sectional view of the surroundings of a combustion chamber 4. Fig. 3 is a schematic partial perspective view of a portion of a burner assembly 32 (32A) according to one embodiment. Fig. Figure 4 is a schematic representation of a portion of the burner assembly 32 (32A) as viewed from upstream in the air flow direction along the central axis L (example of view A of Fig. 2). Fig. Figure 5 is a schematic representation of a section of the cross section BB of Fig. 4. Fig. Figure 6 is a schematic diagram showing a portion of the cross section CC of Fig. 4 shows. Fig. 7 is a schematic cross-sectional view of a portion of a burner assembly 032 according to a comparative example. Fig. 8 is a diagram showing the distribution of flow velocity (axial flow velocity) in the direction of the central axis O in a region S2 of Fig. 7 shows. Fig. 9 is a diagram showing the distribution of the flow velocity in the direction along the central axis O in a region S1 of Fig. 5. Fig. 10 is a schematic partial perspective view of a portion of a burner assembly 32 (32B) according to another embodiment. Fig. Figure 11 is a schematic representation of a portion of the burner assembly 32 (32B) as viewed from upstream in the air flow direction along the central axis L (example of view A of Fig. 2). Fig. Figure 12 is a schematic diagram showing a portion of the cross section CC of Fig. 11 shows. Fig. Figure 13 is a schematic diagram showing a portion of the cross section FF of Fig. 11 shows. Fig. Figure 14 is a representation of the flow of fuel and air in the cross section CC of Fig. 4 in the burner arrangement 32 (32A). Fig. 15 is a diagram showing the distribution of flow velocity in the direction along the central axis O in a region S4 of Fig. 14 in the burner arrangement 32 (32A). Fig. 16 is a diagram showing the distribution of flow velocity in the direction along the central axis O in a region S3 of Fig. 12 in the burner arrangement 32 (32B). DETAILED DESCRIPTION

[0015] Embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, dimensions, materials, shapes, relative positions, and the like of components described or illustrated in the drawings as embodiments are intended to be illustrative only and do not affect the scope of the present invention unless specifically indicated.

[0016] For example, an expression of a relative or absolute arrangement such as "in a direction", "along a direction", "parallel", "orthogonal", "centered", "concentric" and "coaxial" should not be construed as indicating only the arrangement in a strictly literal sense, but also includes a condition in which the arrangement is relatively offset by a tolerance or by an angle or a distance, whereby the same function can be achieved.

[0017] For example, an expression for an equal state such as "equal", "corresponding" and "uniform" should not be understood to indicate only the state in which the characteristic is strictly equal, but also to include a state in which there is a tolerance or difference where the same function can still be achieved.

[0018] Furthermore, for example, the expression of a shape such as a rectangular shape or a cylindrical shape is not only to be understood as the geometrically strict shape, but also includes a shape with unevenness or beveled corners within the range where the same effect can be achieved.

[0019] On the other hand, expressions such as “comprise”, “comprise”, “have”, “contain” and “represent” should not be understood as excluding other components.

[0020] Fig. 1 is a schematic diagram of the configuration of a gas turbine 100 according to an embodiment of the present disclosure. As shown in Fig. 1, the gas turbine 100 according to one embodiment includes a compressor 2 for compressing air (i.e., generating compressed air) serving as an oxidizer supplied to a combustion chamber 4, a combustion chamber 4 (gas turbine combustor) for generating combustion gas using the compressed air and fuel, and a turbine 6 configured to be driven by the combustion gas discharged from the combustion chamber 4. In the case of the gas turbine 100 for power generation, a generator (not shown) is connected to the turbine 6 so that the rotational energy of the turbine 6 generates electric power.

[0021] In the combustor 4 of the gas turbine 100, a gas mixture of fuel and air is combusted to generate the combustion gas. Examples of the fuel combusted in the combustor 4 include hydrogen, methane, light oil, heavy oil, jet fuel, natural gas, and gasified coal, and any one or more of them may be combined for combustion.

[0022] The compressor 2 includes a compressor housing 10, an air inlet 12 disposed on an inlet side of the compressor housing 10 for drawing in air, a rotor 8 disposed to penetrate both the compressor housing 10 and a turbine housing 22, and a plurality of different blades disposed within the compressor housing 10. The plurality of different blades includes an inlet guide vane 14 disposed adjacent to the air inlet 12, a plurality of stator guide vanes 16 fixed to the compressor housing 10, and a plurality of rotor blades 18 inserted into the rotor 8 to alternate with the stator guide vanes 16.In the compressor 2, the air drawn in from the air inlet 12 flows through the plurality of stator vanes 16 and the plurality of rotor blades 18 to be compressed into compressed air having a high temperature and high pressure. The compressed air having a high temperature and high pressure is directed from the compressor 2 to the combustion chamber 4 of a subsequent stage.

[0023] A plurality of combustion chambers 4 are arranged at intervals in the circumferential direction around the rotor 8. The combustion chamber 4 is supplied with fuel and the compressed air generated in the compressor 2 and burns the fuel to produce combustion gas, which serves as a working fluid of the turbine 6. The combustion gas is passed from the combustion chamber 4 to the turbine 6 in a later stage.

[0024] The turbine 6 includes a turbine casing 22 and a plurality of different blades arranged in the turbine casing 22. The plurality of different blades includes a plurality of stator vanes 24 fixed to the turbine casing 22 and a plurality of rotor blades 26 fitted to the rotor 8 so as to be arranged alternately with the stator vanes 24. In the turbine 6, the rotor 8 is rotated as the combustion gas flows through the plurality of stator vanes 24 and the plurality of rotor blades 26. In this way, the generator (not shown) connected to the rotor 8 is driven.

[0025] Furthermore, an exhaust chamber 30 is connected to the downstream side of the turbine housing 22 via an exhaust casing 28. The combustion gas that has driven the turbine 6 is discharged to the outside through the exhaust casing 28 and the exhaust chamber 30.

[0026] Fig. 2 is a cross-sectional view of the surroundings of the combustion chamber 4. The combustion chamber 4 comprises a burner assembly 32, a cylindrical housing 20 with a bottom for receiving the burner assembly 32, and a combustion liner 25 which forms a space in which a flame forms downstream of the burner assembly 32. In Fig. 2, the dashed line shows a central axis L common to the housing 20, the burner assembly 32, and the combustion liner 25. The burner assembly 32 is disposed inside the housing 20 of the combustion chamber 4. In the illustrated exemplary embodiment, the burner assembly 32 is held inside a cylindrical member 34 disposed inside the housing 20. The cylindrical member 34 is supported by the housing 20 via a plurality of support portions 35 arranged at intervals around the central axis L. An air passage 36 for the compressed air flowing from a housing 40 is formed between the housing 20 and the outer peripheral surface of the cylindrical member 34 (between the housing 20 and the outer peripheral surface of the burner assembly 32).

[0027] The compressed air flowing from the housing 40 into the air passage 36 passes through an axial gap 23 between the burner assembly 32 and a bottom surface 21 of the housing 20 and, together with fuel, enters a plurality of mixing passages 46 of the burner assembly 32, which will be described later. The fuel and air are mixed in the burner assembly 32, and the mixture is ignited by an igniter (not shown) to form a flame in the combustion liner 25 and produce the combustion gas.

[0028] Fig. 3 is a schematic partial perspective view of a portion of a burner assembly 32 (32A) according to one embodiment. Fig. Figure 4 is a schematic representation of a portion of the burner assembly 32 (32A) as viewed from upstream in the air flow direction along the central axis L (e.g., view A of Fig. 2). Fig. Figure 5 is a schematic representation of a section of the cross section BB of Fig. 4. Fig. Figure 6 is a schematic diagram showing a portion of the cross section CC of Fig. 4 shows.

[0029] For example, the burner assembly 32, as shown in Fig. 3 or Fig. 4, a plurality of burners 42 for mixing fuel and air.

[0030] For example, as described in one of the Fig. 3 to 5, each burner 42 has a plurality of fuel nozzles 43 for injecting the fuel and a mixing passage 46 into which the fuel injected from the plurality of fuel nozzles 43 and the fuel injected from the housing 40 (see Fig. 1 and Fig. 2) supplied compressed air. In the illustrated exemplary embodiment, each burner 42 includes a mixing passage 46 and four fuel nozzles 43 arranged around the one mixing passage 46, and the fuel is injected from the four surrounding fuel nozzles into the one mixing passage 46. In other words, four mixing passages 46 are arranged around one fuel nozzle 43, and the one fuel nozzle 43 injects the fuel into the four mixing passages 46.

[0031] Each mixing passage 46 is configured as a through-hole extending parallel to each other, and the central axis O of each mixing passage 46 extends in the direction along the central axis L of the housing 20. In the illustrated exemplary embodiment, the central axis O of each mixing passage 46 and the central axis L of the housing 20 are parallel to each other.

[0032] For example, as in Fig. 5, each fuel nozzle 43 has a protruding portion 50 protruding upstream of an inlet 48 of the mixing passage 46 in the air flow direction. Further, each fuel nozzle 43 includes a plurality of fuel injection holes 53 formed on a side surface 44 of the protruding portion 50. In the embodiment shown in Fig. 4, four fuel injection holes 53 are formed on the side surface 44 of the protruding portion 50 at positions corresponding to the four mixing passages 46 around the protruding portion 50. Each fuel injection hole 53 may extend in a direction perpendicular to the central axis O so that the fuel is injected toward the central axis O of the mixing passage 46, or it may extend obliquely to the direction perpendicular to the central axis O.

[0033] For example, as in Fig. 5, an upper surface 54 of the protruding portion 50 (the end surface of the protruding portion 50 in the direction of the axis O, ie, the outer end of the protruding portion 50) has a convex curved surface 56. In the Fig. In the exemplary embodiment illustrated in Figure 5, the entire upper surface 54 of the protruding portion 50 is composed of the convexly curved surface 56, which is uniformly curved. The upper surface 54 of the protruding portion 50 may, for example, be streamlined.

[0034] For example, as in the Fig. 4 and Fig. 6, a passage wall 55 forming the mixing passage 46 is formed in a tubular shape to define the mixing passage 46 with a circular cross section inside, and has the function of a mixing tube for mixing fuel and air. For example, as shown in Fig. 4, among the plurality of burners 42, two burners 42 whose mixing passages 46 are closest to each other are conveniently referred to as a first burner 42 (42a) and a second burner 42 (42b). As shown in the Fig. 4 and Fig. 6, the passage wall 55 forming the mixing passage 46 (46a) of the first burner 42a and the passage wall 55 forming the mixing passage 46 (46b) of the second burner 42b have a partition section 58 (58ab) separating the mixing passage 46a of the first burner 42a from the mixing passage 46b of the second burner 42b. Fig. 4, the passage wall 55 of each mixing passage 46 has the separating portion 58 in common with the passage walls 55 of a plurality of mixing passages 46 (four mixing passages 46 in the illustrated embodiment) surrounding it.

[0035] As in Fig. 6, the thickness t of the partition portion 58ab in the cross section CC of the burner assembly 32A is constant in the direction along the center axis O of the first burner 42a. An upstream end surface 59 of the partition portion 58ab in the air flow direction is formed in a flat shape. Further, as shown in Fig. 4, the thickness t of the separating section 58ab increases with increasing distance from the cross section CC. As shown in the Fig. 4 and Fig. 6, the cross section CC is a cross section (first cross section) passing through the center C1 of the inlet 48 of the mixing passage 46a of the first burner 42a and the center C2 of the inlet 48 of the mixing passage 46b of the second burner 42b and extending along the central axis O of the mixing passage 46 of the first burner 42a.

[0036] The effects achieved with the burner arrangement 32A are now compared to a Fig. 7 described in the comparative example shown.

[0037] Fig. 7 is a schematic cross-sectional view of a portion of a burner assembly 032 according to a comparative example. Fig. Fig. 8 is a diagram showing the distribution of flow velocity (axial flow velocity) in the direction along the central axis O in a region S2 of Fig. 7 shows. Fig. 9 is a diagram showing the distribution of the flow velocity in the direction along the central axis O in a region S1 of Fig. 5.

[0038] In the Fig. In the comparative example shown in Fig. 7, the upper surface 054 of the protruding portion 050 of the fuel nozzle 043 is flat, and an edge 045 is formed at a junction between the upper surface 054 of the protruding portion 050 and the side surface 040 of the protruding portion 050. This causes the separation of the air flow at the edge 045, so that a low flow velocity and high fuel concentration region tends to form near the fuel injection hole 053 (near the fuel spray), as shown in Fig. 8. In this way, the risk of backflow, ie backflow from the outlet of the mixing passage 046, tends to increase.

[0039] In contrast, in the burner assembly 32A according to the aforementioned embodiment, since the upper surface of the protruding portion 50 of the fuel nozzle 43 includes the convex curved surface 56, the flow separation from the upper surface 54 of the fuel nozzle 43 to the side surface 44 can be prevented. Thus, it is unlikely that a low flow velocity and high fuel concentration region will form near the fuel injection hole 53, as in Fig. 9. In this way, the risk of flashback and the risk of flame holding can be reduced. In this way, burn damage to the burners 42 due to flashback and flame holding can be prevented.

[0040] Next, a burner assembly 32 (32B) according to another embodiment will be described with reference to the Fig. 10 to 13 described.

[0041] Fig. 10 is a schematic partial perspective view of a portion of a burner assembly 32 (32B) according to another embodiment. Fig. Figure 11 is a schematic representation of a portion of the burner assembly 32 (32B) as viewed from upstream in the air flow direction along the central axis L (e.g., view A of Fig. 2). Fig. Figure 12 is a schematic representation of a section of the cross section CC of Fig. 11. Fig. Figure 13 is a schematic diagram showing a portion of the cross section FF in Fig. 11 shows.

[0042] The burner assembly 32B, which is located in the Fig. The burner assembly 32B shown in FIGS. 10 to 13 differs from the burner assembly 32A only in the shape of the end surface 59 of the partition portion 58, and the configuration is otherwise the same as that of the burner assembly 32A. Therefore, the same reference numerals are used for the other configuration, and their description is omitted.

[0043] As in Fig. As shown in Figure 10, in the burner assembly 32B, the end surface 59 (the upstream end surface in the air flow direction) of the partition portion 58 separating the two nearest mixing passages 46 has a saddle shape. The shape of the end surface 59 of the partition portion 58 will now be described in detail.

[0044] As in Fig. 11, in the burner assembly 32B, among the plurality of burners 42, two adjacent burners 42 are conveniently referred to as a first burner 42 (42a) and a second burner 42 (42b), wherein the passage wall 55 forming the mixing passage 46 (46a) of the first burner 42a and the passage wall 55 forming the mixing passage 46 (46b) of the second burner 42b commonly have a partition portion 58 (58ab) separating the mixing passage 46a of the first burner 42a from the mixing passage 46b of the second burner 42b.

[0045] As in Fig. 12, the thickness t of the partition portion 58ab in the cross section CC of the burner assembly 32B decreases upstream in the air flow direction in an upstream end portion 61 of the partition portion 58ab in the air flow direction. Further, the upstream end surface 59 of the partition portion 58ab in the air flow direction in the cross section CC includes a convex curved line 60. In the illustrated exemplary embodiment, in the cross section CC, the entire end surface 59 of the partition portion 58ab consists of the convex curved line 60, which is smoothly curved. In the cross section CC, the end surface 59 of the partition portion 58ab may be formed in a streamlined shape, for example. As shown in FIGS. Fig. 11 and Fig. 12, the cross section CC is a cross section (first cross section) passing through the center C1 of the inlet 48 of the mixing passage 46a of the first burner 42a and the center C2 of the inlet 48 of the mixing passage 46b of the second burner 42b and extending along the central axis O of the mixing passage 46a of the first burner 42a.

[0046] Here, as in the Fig. 11 and Fig. 13, among the four fuel nozzles 43 comprising the first burner 42a, two fuel nozzles 43 having the protruding portions 50 adjacent to the separating portion 58ab are conveniently referred to as a first fuel nozzle 43 (43a) and a second fuel nozzle 43 (43b). Thus, the protruding portion 50 of the second fuel nozzle 43b is located on the opposite side of a plane V encompassing the cross-section CC from the protruding portion 50 of the first fuel nozzle 43a.

[0047] As in Fig. 13, the height H of the separation portion 58ab increases as it approaches the protruding portion 50 of the first fuel nozzle 43a from the position of the plane V (the position of the cross section CC) and increases as it approaches the protruding portion 50 of the second fuel nozzle 43b from the position of the plane V. Furthermore, in the embodiment shown in Fig. 13, the upstream end surface 59 of the partition portion 58ab in the air flow direction forms a concave curved line 62 connecting the side surface 44 of the upstream portion 50 of the first fuel nozzle 43a and the side surface 44 of the protruding portion 50 of the second fuel nozzle 43b. As shown in Fig. 11, the cross section FF is a cross section perpendicular to a straight line U connecting the center C1 of the inlet 48 of the mixing passage 46a of the first burner 42a and the center C2 of the inlet 48 of the mixing passage 46b of the second burner 42b.

[0048] The effects achieved with the burner arrangement 32B will now be described in comparison with the burner arrangement 32A.

[0049] Fig. 14 is a representation of the flow of fuel and air in the cross section CC of Fig. 4 for the burner arrangement 32A. Fig. 15 is a diagram showing the distribution of flow velocity in the direction along the central axis O in a region S4 of Fig. 14 for the burner assembly 32A. Fig. 16 is a diagram showing the distribution of flow velocity in the direction along the central axis O in a region S3 of Fig. 12 for the burner assembly 32B.

[0050] In the burner assembly 32B, similarly, since the upper surface 54 of the protruding portion 50 of the fuel nozzle 43 includes the convex curved surface 56, as shown in Fig. 12, the flow separation from the top surface 54 of the fuel nozzle 43 to the side surface 44 as in the burner assembly 32A can be prevented. Thus, a region of low flow velocity and high fuel concentration is unlikely to form near the fuel injection hole 53. In this way, the risk of flashback and the risk of flame holding can be reduced. In this way, combustion damage to the burners 42 due to flashback and flame holding can be prevented.

[0051] As in Fig. 14, in the burner assembly 32A, since the end surface 59 of the partition portion 58 is formed in a flat shape, an edge 45 is formed at a junction between a wall surface 63 of the partition portion 58 (the wall surface of the passage wall 55 of the mixing passage 46) and the end surface 59 of the partition portion 58, and the air flow can be separated at the edge 45. Accordingly, as shown in Fig. 15, a region of low flow velocity and high fuel concentration may be formed in a limited area near the inlet 48 of the mixing passage 46. In this way, there is a limited but definite risk of flashback, which is a flashback at the outlet of the mixing passage 46.

[0052] In contrast, in the burner assembly 32B, as described with reference to Fig. 12, etc., the thickness t of the partition portion 58 upstream in the air flow direction decreases in the upstream end portion 61 of the partition portion 58 in the air flow direction. Further, the upstream end surface 59 of the partition portion 58 in the air flow direction in the cross section CC includes the convex curved line 60. In this way, the flow separation near the inlet 48 of the mixing passage 46 can be prevented. As shown in Fig. 16, it is therefore unlikely that a region of low flow velocity and high fuel concentration will form near the wall surface 63 of the separation section 58 near the inlet 48 of the mixing passage 46. In this way, the risk of flashback and the risk of flame holding can be reduced. Thus, combustion damage to the burners 42 due to flashback and flame holding can be prevented.

[0053] Furthermore, in the burner assembly 32B, as described with reference to Fig. 13 etc., the height H of the separation portion 58 increases in the direction toward the protruding portion 50 of the first fuel nozzle 43a from the position of the plane V (the position of the cross section CC), and increases in the direction toward the protruding portion 50 of the second fuel nozzle 43b from the position of the plane V. Furthermore, in the embodiment shown in Fig.13, the upstream end surface 59 of the partition portion 58ab in the air flow direction forms the concave curved line 62 connecting the side surface 44 of the upstream portion 50 of the first fuel nozzle 43a and the side surface 44 of the upstream portion 50 of the second fuel nozzle 43b. This allows the air flowing from the side surface 44 of the protruding portion 50 to the end surface 59 of the partition portion 58 to be smoothly introduced into the mixing passage 46, and a low flow velocity, high fuel concentration region is unlikely to be formed near the wall surface 63 of the partition portion 58 near the inlet 48 of the mixing passage 46. Thus, combustion damage to the burner 42 due to flashback and flame holding can be prevented.

[0054] The present disclosure is not limited to the aforementioned embodiments, but includes modifications of the aforementioned embodiments and embodiments consisting of combinations of these embodiments.

[0055] For example, in the aforementioned embodiments, the burner assemblies 32A, 32B were described in which the plurality of fuel nozzles 43 and the passage walls 55 forming the plurality of mixing passages 46 are integrally formed as a single component. However, each fuel nozzle and each mixing passage may be formed separately as a single component, or multiple fuel nozzles and multiple mixing passages may be composed of any number of components.

[0056] Furthermore, in the above embodiments, each burner 42 comprises a plurality of fuel nozzles 43, but each burner 42 may also have only one fuel nozzle 43 or at least one fuel nozzle 43.

[0057] The content described in the above embodiments is to be understood, for example, as follows.

[0058] (1) A burner assembly according to the present disclosure is a burner assembly (e.g., the above-described burner assembly 32 (32A, 32B)) that includes a plurality of burners (e.g., the above-described burners 42) for mixing fuel and air. Each of the plurality of burners includes: at least one fuel nozzle (e.g., the aforementioned fuel nozzle 43) for injecting the fuel, and a mixing passage (e.g., the aforementioned mixing passage 46) into which the fuel injected from the at least one fuel nozzle and the air are introduced. Each of the at least one fuel nozzle includes a protruding portion (e.g., the above-described protruding portion 50) protruding upstream of an inlet (e.g., the above-described inlet 48) of the mixing passage in a flow direction of the air, and each of the at least one fuel nozzle includes at least one fuel injection hole (e.g.,The above-described fuel injection hole 53 is formed on a side surface (e.g., the above-described side surface 44) of the protruding portion. An upper surface (e.g., the above-described upper surface 54) of the protruding portion includes a convex curved surface (e.g., the above-described convex curved surface 56).

[0059] In the burner assembly described in (1), since the upper surface of the protruding portion of the fuel nozzle includes the convex curved surface, the flow separation from the upper surface of the fuel nozzle to the side surface can be prevented. Thus, a low flow velocity and high fuel concentration region is unlikely to form near the fuel injection hole (near the fuel jet). In this way, the risk of flashback, that is, a flashback from the outlet of the mixing passage, can be reduced.

[0060] (2) In some embodiments, in the burner assembly described in (1), the plurality of burners includes a first burner (e.g., the above-described first burner 42 (42a)) and a second burner (e.g., the above-described second burner 42 (42b)) having the mixing passage closest to the mixing passage of the first burner. A passage wall (e.g., the aforementioned passage wall 55) forming the mixing passage of the first burner and a passage wall (e.g., the aforementioned passage wall 55) forming the mixing passage of the second burner have in common a partition portion (e.g., the aforementioned partition portion 58 (58ab)) separating the mixing passage of the first burner from the mixing passage of the second burner. A thickness (e.g., the aforementioned thickness t) of the partition portion decreases upstream in the air flow direction in an upstream end portion (e.g.,the aforementioned end section 61) of the separating section in the direction of air flow.

[0061] In the burner arrangement described in (2), since the thickness of the partition portion decreases in the air flow direction at the upstream end portion of the partition portion, flow separation on the surface of the partition portion near the inlet of the mixing passage can be prevented. Thus, a low flow velocity and high fuel concentration region is unlikely to form near the wall surface of the partition portion near the inlet of the mixing passage, reducing the risk of flashback and flame retention.

[0062] (3) In some embodiments, in the burner assembly described in (2), when a cross section of the partition portion passing through a center of the inlet of the mixing passage of the first burner and a center of the inlet of the mixing passage of the second burner and extending along a center axis of the mixing passage of the first burner is defined as a first cross section (e.g., the aforementioned cross section CC), an upstream end surface (e.g., the aforementioned end surface 59) of the partition portion in the flow direction of the air includes a convex curved line (e.g., the aforementioned convex curved line 60) in the first cross section.

[0063] In the burner arrangement described in (3), since the upstream end surface of the partition section in the air flow direction includes the convex curved line in the first cross section, flow separation on the surface of the partition section near the inlet of the mixing passage can be prevented. Thus, a low flow velocity and high fuel concentration region is unlikely to form near the wall surface of the partition section near the inlet of the mixing passage, reducing the risk of flashback and flame holding.

[0064] (4) In some embodiments, in the burner assembly described in (3), the first burner includes a first fuel nozzle (e.g., the aforementioned first fuel nozzle 43 (43a)) and a second fuel nozzle (e.g., the aforementioned second fuel nozzle 43 (43b)) for injecting the fuel as the at least one fuel nozzle. The protruding portion of the first fuel nozzle is disposed adjacent to the partition portion, and the protruding portion of the second fuel nozzle is disposed adjacent to the partition portion on an opposite side of a plane (e.g., the aforementioned plane V) including the first cross section from the protruding portion of the first fuel nozzle. A height (e.g., the aforementioned height H) of the partition portion increases as it extends from the first cross section toward the protruding portion of the first fuel nozzle.

[0065] In the burner arrangement described in (4), since the height of the partition increases from the first cross section to the protruding portion of the first fuel nozzle, the air flowing from the side surface of the protruding portion of the first fuel nozzle to the end surface of the partition can be smoothly introduced into the mixing passage. Thus, a low flow velocity, high fuel concentration region is unlikely to form near the wall surface of the partition near the inlet of the mixing passage. Thus, combustion damage to the burners due to flashback and flame holding can be prevented.

[0066] (5) In some embodiments, in the burner assembly described in (4), the end surface of the partition portion includes a concave curved line (e.g., the above-mentioned concave curved line 62) connecting the side surface of the protruding portion of the first fuel nozzle and the side surface of the protruding portion of the second fuel nozzle in a cross section (e.g., the above-mentioned cross section FF) perpendicular to a straight line (e.g., the above-mentioned straight line U) connecting the center of the inlet of the mixing passage of the first burner and the center of the inlet of the mixing passage of the second burner.

[0067] In the burner assembly described in (5), since the end surface includes the concave curved line connecting the side surface of the protruding portion of the first fuel nozzle and the side surface of the protruding portion of the second fuel nozzle in the cross section perpendicular to the straight line, the air flowing from each of the side surface of the protruding portion of the first fuel nozzle and the side surface of the protruding portion of the second fuel nozzle to the end surface of the partition portion can be smoothly introduced into the mixing passage. Thus, a low flow velocity and high fuel concentration region is unlikely to form near the wall surface of the partition portion near the inlet of the mixing passage. In this way, combustion damage of the burners due to flashback and flame holding can be prevented.

[0068] (6) A gas turbine combustor (e.g., the aforementioned combustor 4) according to the present disclosure comprises: the burner assembly described in any one of (1) to (5), and a combustion liner (e.g., the aforementioned combustion liner 25) forming a space in which a flame is formed downstream of the burner assembly.

[0069] In the gas turbine combustor described in (6), since the gas turbine combustor includes the burner assembly described in any one of (1) to (5), the risk of flashback and flame holding can be reduced. Consequently, the combustor can be used stably.

[0070] (7) A gas turbine (e.g., the aforementioned gas turbine 100) according to the present disclosure includes: a compressor (e.g., the aforementioned compressor 2); a gas turbine combustor (e.g., the aforementioned combustor 4) configured to be supplied with air and fuel compressed by the compressor and to generate a combustion gas by burning the fuel; and a turbine (e.g., the aforementioned turbine 6) driven by the combustion gas generated by the gas turbine combustor. The gas turbine combustor is the gas turbine combustor described in (6).

[0071] Since the gas turbine incorporates the gas turbine combustor described in (6), the risk of flashback and flame holding in the gas turbine described in (7) can be reduced, and combustion damage to the burners can be prevented. Consequently, the gas turbine can operate stably. List of reference symbols 2 compressors 4 combustion chamber 6 turbines 8 Rotor 10 Compressor housing 12.48 Admission 14 Inlet guide vane 16.24 Stator guide vane 18.26 rotor blade 20 housings 22 Turbine housing 25 Combustion lining 28 Outlet housing 30 Outlet chamber 32(32A,32B) burner arrangement 34 cylindrical element 35 supporting section 36 Air passage 40 housings 42 burners 42a first burner 42b second burner 43 Fuel nozzle 43a first fuel nozzle 43b second fuel nozzle 44 side surface 45 edge 46,46a,46b Mixing passage 50 preceding section 53 Fuel injection hole 54 upper surface 55 Passage wall 56 convex curved surface 58.58ab dividing section 59 Final surface 60 convex curved line 61 final section 62 concave curved line 63 Wall surface 100 gas turbines

Claims

[1] A burner assembly (32) having a plurality of burners (42) for mixing fuel and air, wherein each of the plurality of burners (42) comprises: at least one fuel nozzle (43) for injecting the fuel, and a mixing passage (46) into which the fuel injected from the at least one fuel nozzle (43) and the air are introduced, each of the at least one fuel nozzle (43) comprising a projecting portion (50) projecting upstream of an inlet (48) of the mixing passage (46) in a flow direction of the air, wherein each of the at least one fuel nozzle (43) comprises at least one fuel injection hole (53) formed on a side surface (44) of the projecting portion (50), wherein the plurality of burners (42) comprises a first burner (42a) and a second burner (42b) having the mixing passage (46b) closest to the mixing passage (46a) of the first burner (42a), wherein a passage wall (55) forming the mixing passage (46a) of the first burner (42a) and a passage wall (55) forming the mixing passage (46b) of the second burner (42b) have in common a separating section (58ab) separating the mixing passage (46a) of the first burner (42a) from the mixing passage (46b) of the second burner (42b), wherein, when a cross section of the separating portion (58ab) passing through a center (C1) of the inlet (48) of the mixing passage (46a) of the first burner (42a) and a center (C2) of the inlet (48) of the mixing passage (46b) of the second burner (42b) and along a center axis (O) of the mixing passage (46a) of the first burner (42a) is defined as a first cross section, and wherein the projecting portion (50) projects upstream from a position of an upstream end surface (59) of the separating portion (58ab) in the first cross section in the flow direction of the air, characterized by that an entire upper surface (54) of the projecting portion (50) is streamlined from a convexly curved surface (56). [2] The burner assembly (32) according to claim 1, wherein a thickness (t) of the partition portion (58ab) decreases upstream in the flow direction of the air in an upstream end portion (61) of the partition portion (58ab) in the flow direction of the air. [3] The burner assembly (32) according to claim 2, wherein the upstream end surface (59) of the partition portion (58ab) in the flow direction of the air includes a convex curved line in the first cross section. [4] The burner assembly (32) according to claim 3, wherein the first burner (42a) comprises a first fuel nozzle (43a) and a second fuel nozzle (43b) for injecting the fuel as the at least one fuel nozzle (43), wherein the projecting portion (50) of the first fuel nozzle (43a) is arranged adjacent to the separating portion (58ab), wherein the protruding portion (50) of the second fuel nozzle (43b) is arranged adjacent to the separating portion (58ab) on an opposite side of a plane (V) comprising the first cross section from the protruding portion (50) of the first fuel nozzle (43a), and wherein a height of the separating portion (58ab) increases in the direction from the first cross section to the protruding portion (50) of the first fuel nozzle (43a). [5] The burner assembly (32) according to claim 4, wherein the end surface (59) of the partition portion (58ab) includes a concave curved line connecting the side surface (44) of the protruding portion (50) of the first fuel nozzle (43a) and the side surface (44) of the protruding portion (50) of the second fuel nozzle (43b) in a cross section perpendicular to a straight line (U) connecting the center (C1) of the inlet (48) of the mixing passage (46a) of the first burner (42a) and the center (C2) of the inlet (48) of the mixing passage (46b) of the second burner (42b). [6] A gas turbine combustion chamber (4) with: the burner arrangement (32) according to one of claims 1 to 5, and a combustion liner (25) forming a space in which a flame forms downstream of the burner assembly. [7] A gas turbine (100) with: a compressor (2), a gas turbine combustion chamber (4) designed to be supplied with air and fuel compressed by the compressor (2) and to produce a combustion gas by combustion of the fuel, and a turbine (6) driven by the combustion gas generated by the gas turbine combustion chamber (4), wherein the gas turbine combustion chamber (4) is the gas turbine combustion chamber (4) according to claim 6.

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