Combustors and gas turbines

Abstract

To provide a burner capable of further preventing flashback while improving flame stability.SOLUTION: The burner comprises a mixer including a plurality of mixing pipes penetrating through the upstream end face and the downstream end face of the mixer to intersect the burner axis to function as flow paths through which air is introduced from the upstream end face, and fuel feeders feeding fuel to air present in the mixing pipes to produce a mixed fluid. The pressure loss coefficient of the flow path of each of the mixing pipes is different from each other so as to make the difference in the flow velocity of the mixed fluid at the downstream end face of each of the mixing pipes greater in comparison with a case where the flow paths of the mixing pipes each have the same shape.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] For example, Patent Document 1 discloses a cluster combustor as an example of a combustor used in a gas turbine. The cluster combustor has a plurality of mixing pipes arranged side by side with air introduced thereinto, and a fuel supply section that injects fuel from the inner peripheral surfaces of these mixing pipes. Along with the injection of fuel, a mixed fluid of air and fuel flows through the mixing pipes and is ejected to the downstream side. At this time, when the mixed fluid ignites, a plurality of small-scale flames are formed at the outlets of the respective mixing pipes.

[0003] In the above cluster combustor, in order to improve the non-uniformity of the air flow rate introduced into each mixing pipe, the shapes of the inlet portions of the respective mixing pipes are made different from each other. That is, by expanding the inlet portion of the mixing pipe with a small air inflow amount, more air flows into the mixing pipe. Thereby, the air flow rate in each mixing pipe is made uniform, and the flow velocity of the mixed fluid at the outlet of the mixing pipe is made uniform.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the combustor of Patent Document 1, the positions of the flame surfaces formed by the flames at the outlets of the respective mixing pipes being continuous are in a state where they are aligned with each other in the axial direction of the combustor, and combustion vibration may occur.

[0006] This disclosure was made to solve the above-mentioned problems and aims to provide a combustor and a gas turbine that can suppress vibration. [Means for solving the problem]

[0007] To solve the above problems, the combustor according to this disclosure has a plurality of mixing tubes that penetrate from the upstream end face to the downstream end face intersecting the combustor axis, thereby forming a flow path through which air is introduced from the upstream end face side. cylindrical The system comprises a mixing unit and a fuel supply unit that supplies fuel to the air in the mixing tube to generate a mixed fluid, wherein the pressure loss coefficients of the flow paths of the mixing tubes are different from each other, such that the difference in the flow velocity of the mixed fluid at the downstream end faces of the mixing tubes is greater than when the flow paths of each mixing tube have the same shape. The mixing tubes are parallel to the combustor axis at their downstream end faces, and the cross-sectional shape of the mixing tubes intersecting the combustor axis is uniform. In a plurality of adjacent mixing tubes in the radial direction of the mixing section, the flow velocity of the mixed fluid at the downstream end faces is configured to alternately differ. The mixing section is formed by bundling a plurality of mixing tubes into a first group and a plurality of second groups. The first group is arranged in an annular region centered on the combustor axis, and the plurality of second groups are arranged on the outer circumference of the first group, spaced apart in the circumferential direction. It is.

[0008] The gas turbine according to this disclosure comprises a compressor that generates air, a combustor that generates combustion gas by burning a mixed fluid produced by mixing fuel with the air compressed by the compressor, and a turbine driven by the combustion gas. [Effects of the Invention]

[0009] The combustor and gas turbine of this disclosure can suppress vibrations. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the general configuration of a gas turbine according to the first embodiment of this disclosure. [Figure 2] This is a longitudinal cross-sectional view showing a schematic configuration of a combustor according to the first embodiment of this disclosure. [Figure 3] This is a view of the mixing section of the combustor according to the first embodiment of this disclosure, as seen from the direction of the combustor axis. [Figure 4] This is an enlarged view of the main part of the combustor according to the first embodiment of this disclosure. [Figure 5]It is a diagram showing the flow velocity distribution of air and the mixed fluid and the distribution of the flame surface of the combustor of the comparative example. [Figure 6] It is a diagram showing the flow velocity distribution of air and the mixed fluid and the distribution of the flame surface of the combustor according to the first embodiment of the present disclosure. [Figure 7] It is a longitudinal sectional view showing the schematic configuration of the combustor according to the second embodiment of the present disclosure. [Figure 8] It is an enlarged view of the main part of the combustor according to the second embodiment of the present disclosure. [Figure 9] It is an enlarged view of the main part of the combustor according to the modified example.

Mode for Carrying Out the Invention

[0011] <First Embodiment> Hereinafter, the first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6. As shown in FIG. 1, the gas turbine 1 according to the present embodiment has a compressor 2 that compresses air, a combustor 3 that generates combustion gas, and a turbine 4 that is driven by the combustion gas. A plurality of combustors 3 are provided at intervals in the circumferential direction around the rotation axis of the gas turbine 1. The combustor 3 mixes fuel with the air compressed by the compressor 2 and burns it to generate high-temperature and high-pressure combustion gas.

[0012] <Combustor> Hereinafter, the configuration of the combustor 3 will be described with reference to FIGS. 2 to 4. As shown in FIG. 2, the combustor 3 has an outer cylinder 10, an end cover 11, an inner cylinder 13, a mixing section 20, a support section 38, and a fuel nozzle 40 as an example of a fuel supply section.

[0013] <Outer Cylinder> The cylindrical body has a cylindrical shape centered on the combustor axis O (hereinafter simply referred to as axis O) that is the center of the combustor 3.

[0014] <End Cover> The end cover is in the shape of a disk that closes one end (the left side in FIG. 2) of the outer cylinder 10 in the direction of the axis O. The end of the outer cylinder 10 in the direction of the axis O on one side abuts against the end cover 11. Inside the end cover 11, a fuel header 12 is formed as a space. Fuel F is supplied to the fuel header 12 from the outside. As the fuel F, for example, a mixed fuel of natural gas and hydrogen may be used.

[0015] <Inner cylinder> The inner cylinder 13 is coaxially arranged inside the outer cylinder 10. The inner cylinder 13 is in the shape of a cylinder extending in the direction of the axis O inside the outer cylinder 10. One end of the inner cylinder 13 in the direction of the axis O is spaced apart from the end cover 11 in the direction of the axis O. The outer diameter of the inner cylinder 13 is smaller than the outer diameter of the inner cylinder 13. As a result, an annular flow path is formed between the outer peripheral surface of the inner cylinder 13 and the inner peripheral surface of the outer cylinder 10. Compressed air A compressed by the compressor 2 flows through this flow path from the other side (the right side in FIG. 2) in the direction of the axis O toward the one side in the direction of the axis O.

[0016] <Mixing part> The mixing part 20 is in the shape of a cylinder centered on the axis O and has an upstream end face 21 and a downstream end face 22. The mixing part 20 is provided so as to be coaxially fitted inside the inner cylinder 13.

[0017] The upstream end face 21 is an end face facing one side in the direction of the axis O in the mixing part 20 and is in the shape of a plane orthogonal to the axis O. The upstream end face 21 is arranged at the same position in the direction of the axis O as the end face of the inner cylinder 13 on one side in the direction of the axis O.

[0018] The downstream end face 22 is an end face facing the other side in the direction of the axis O in the mixing part 20 and is in the shape of a plane orthogonal to the axis O. The downstream end face 22 is located on the one side in the direction of the axis O rather than the end face of the inner cylinder 13 on the other side in the direction of the axis O. As a result, a space is partitioned by the inner peripheral surface of the inner cylinder 13 and the downstream end face 22 of the mixing part 20. This space is the combustion space of the combustor 3.

[0019] The mixing section 20 has multiple mixing pipes 30 that extend in the direction of axis O so as to penetrate from the upstream end face 21 to the downstream end face 22. The inside of the mixing pipes 30 is a flow path where one side in the direction of axis O is the upstream side and the other side in the direction of axis O is the downstream side.

[0020] As shown in Figure 3, the mixing section 20 has multiple mixing tube groups, each consisting of multiple mixing tubes 30 bundled together. In this embodiment, the mixing tube groups consist of a first group B1 and a second group B2.

[0021] The first group B1 is a group of mixed tubes arranged in the central region of the downstream end face 22, that is, in an annular region centered on the axis O. The second group B2 is a group of mixing tubes arranged on the outer periphery of the first group B1, and multiple groups are formed with spacing in the circumferential direction. The mixing tubes 30 forming the second group B2 are divided into an inner circumferential system R1 and an outer circumferential system R2. The inner circumferential system R1 is formed from multiple mixing tubes 30 arranged in the center of each second group B2. The outer circumferential system R2 is formed from multiple mixing tubes 30 arranged so as to surround the inner circumferential system R1 in each second group B2 from the outer periphery.

[0022] <Fuel nozzle> As shown in Figure 2, the fuel nozzle 40 is tubular in shape and extends in the direction of axis O, and its role is to inject fuel F into the mixing tube 30. Multiple fuel nozzles 40 are provided in a one-to-one relationship with each mixing tube 30. One portion of the fuel nozzle 40 in the direction of axis O is fixed to the end cover 11. The fuel nozzle 40 is provided extending from the end cover 11 to the mixing tube 30.

[0023] One end of the fuel nozzle 40 in the direction of axis O is connected to the fuel header 12 inside the end cover 11. This creates a communication between the fuel header 12 and the inside of the fuel nozzle 40, and fuel F in the fuel header 12 is supplied into the fuel nozzle 40. The other end of the fuel nozzle 40 in the direction of axis O is inserted into the mixing tube 30. As a result, the fuel F that has flowed through the fuel nozzle 40 is injected from the other end of the fuel nozzle 40 in the direction of axis O.

[0024] <Support part> The support portion 38 supports the mixing portion 20 on the end cover 11. One end of the support portion 38 in the direction of axis O is fixed to the end cover 11, and the other end is connected to the outer circumference of the upstream end face 21 of the mixing portion 20. Multiple support portions 38 are formed at intervals in the circumferential direction. Air A flowing from the other side in the direction of axis O towards one side in the flow path between the inner surface of the outer cylinder 10 and the outer surface of the inner cylinder 13 reverses direction to the other side in the direction of axis O by passing through the space between the multiple support portions 38.

[0025] <Detailed configuration of the mixing tube and fuel nozzle> Next, with reference to Figure 4, the detailed configuration of the mixing tube 30 and the fuel nozzle 40 will be described. Each mixing pipe 30 has a main section 31 and an inlet section 32. The main section 31 is a portion that extends in a straight pipe shape in the direction of axis O with a uniform inner diameter, and its downstream end (right side in Figure 4) opens to the downstream end face 22 as an outlet opening 31a. The inlet section 32 is connected to the upstream side (left side in Figure 4) of the main section 31 and extends further upstream, and its upstream end opens to the upstream end face 21 as an inlet opening 32a.

[0026] The inlet section 32 has a bell-mouth shape, with its inner diameter widening towards the upstream side and connecting to the upstream end face 21. The length of the inlet section 32 in the mixing pipe 30 in the direction of axis O is shorter than the length of the main pipe section 31 in the direction of axis O.

[0027] The fuel nozzle 40 has its tip portion 41, which is the portion on the other side in the direction of axis O, inserted into the inlet opening 32a of the mixing tube 30. The tip portion 41 of the fuel nozzle 40 has a tip opening 42a into which fuel F flowing through the fuel passage 42 inside the fuel nozzle 40 is injected. The tip opening 42a is located downstream of the boundary between the main pipe portion 31 and the inlet portion 32. The outer surface of the nozzle, which is the outer surface of the tip portion 41 of the fuel nozzle 40, decreases in diameter towards the tip. The outer diameter of the nozzle outer surface 43 is smaller than the inner diameter of the inlet portion 32 of the mixing tube 30. The central axis of the fuel nozzle 40 coincides with the central axis of the mixing tube 30. As a result, the nozzle outer surface 43 and the inner surface of the inlet portion 32 of the mixing tube 30 form a passage for air A flowing into the inside of the mixing tube 30.

[0028] In this embodiment, as shown in Figure 4, if any two mixing tubes 30 are designated as the first mixing tube 30A and the second mixing tube 30B, the flow path shapes of the inlet portions 32 of the first mixing tube 30A and the second mixing tube 30B are different from each other.

[0029] In other words, in this embodiment, the shapes of the first mixing tube 30A and the second mixing tube 30B are the same. On the other hand, the outer diameter of the nozzle outer surface 43 of the fuel nozzle 40 inserted into the first mixing tube 30A is smaller than the outer diameter of the nozzle outer surface 43 of the fuel nozzle 40 inserted into the second mixing tube 30B. As a result, the flow path shape formed by the nozzle outer surface 43 and the inner surface of the inlet portion 32 is more constricted in the second mixing tube 30B than in the first mixing tube 30A.

[0030] In other words, the cross-sectional shape of the flow path at the inlet 32 ​​is smaller for the second mixing pipe 30B than for the first mixing pipe 30A. The effective cross-sectional area through which air A can flow is smaller for the inlet 32 ​​of the second mixing pipe 30B than for the inlet 32 ​​of the first mixing pipe 30A. As a result, the pressure loss coefficient of the second mixing pipe 30B is smaller than that of the first mixing pipe 30A. Thus, in this embodiment, the pressure loss coefficients of the flow paths of at least one pair of mixing tubes 30 are configured to be different from each other.

[0031] In this embodiment, the amount of fuel supplied from the fuel nozzle 40 to the first mixing tube 30A is greater than the amount of fuel supplied to the second mixing tube 30B. That is, the amount of fuel supplied is greater for mixing tubes 30 with smaller pressure loss coefficients. This adjustment of the fuel supply amount can be achieved by appropriately setting the shape of the fuel passage 42, etc., by installing an orifice in the fuel header 12. This makes it possible to equalize the fuel-air ratio for each mixing tube 30 and achieve stable combustion.

[0032] <Effects and Effects> Next, the operation and effects of the combustion device 3 according to this embodiment will be described. During operation of the gas turbine 1, air A flows through each mixing tube 30, and fuel F is injected from each fuel nozzle 40. The fuel F injected into the mixing tube 30 is mixed with the air A flowing through the mixing tube 30, thereby generating a mixed fluid M. The mixed fluid M is ejected further downstream from the downstream end face 22 of the mixing section 20 through the outlet opening 31a of the mixing tube 30 and ignited. As a result, flames are formed corresponding to the outlet opening 31a of each mixing tube 30, and the generated combustion gas C is sent to the turbine 4.

[0033] If we assume that the flow path shapes of each mixing tube 30 are identical to those of each other, then, as shown in the comparative example in Figure 5, the inlet velocity distribution D1, which is the flow velocity distribution of the air A upstream of each mixing tube 30, and the outlet velocity distribution D2, which is the flow velocity distribution of the downstream of each mixing tube 30, will be similar. In this case, if the variation in the inlet velocity distribution D1 is small, the outlet velocity distribution D2 will also be uniform with small variation. As a result, the flame surface S formed by the flame from each mixing tube 30 will be aligned in the direction of the axis O, and combustion oscillation will occur.

[0034] In contrast, this embodiment resolves the above-mentioned inconvenience by making the pressure loss coefficients of each mixing tube 30 different from each other. In other words, in this embodiment, as shown in Figure 4, the pressure loss coefficients of the first mixing tube 30A and the second mixing tube 30B are different due to the different flow path shapes on the inlet side. More specifically, the pressure loss coefficient of the second mixing tube 30B, which has a more narrowed flow path shape on the inlet side, is larger than that of the first mixing tube 30A.

[0035] If the pressure difference △P between the upstream and downstream sides of the mixing pipe 30 is constant, then the smaller the pressure loss coefficient, the greater the flow velocity of the mixed fluid M at the outlet opening 31a of the mixing pipe 30. Therefore, the flow velocity V2 of the mixed fluid M in the second mixing pipe 30B is smaller than the flow velocity V1 of the mixed fluid M in the first mixing pipe 30A. In other words, the difference in flow velocity of the mixed fluid M flowing out of the first mixing pipe 30A and the second mixing pipe 30B is larger than when the pressure loss coefficients of these mixing pipes 30 are the same.

[0036] Thus, in this embodiment, the pressure loss coefficients of the flow paths of each mixing tube 30 are configured to be different from each other, so that the difference in the flow velocity of the mixed fluid M flowing out of each mixing tube 30 is larger compared to the case where the flow path shapes of each mixing tube 30 are the same. As a result, the variation in the outlet-side flow velocity distribution D2 (see Figure 6) in this embodiment, where the pressure loss coefficient of each mixing tube 30 is varied, is greater than that in the comparative example where each mixing tube 30 has the same shape (see Figure 5). Furthermore, as shown in Figure 6, in this embodiment, the variation in the outlet-side flow velocity distribution D2 is greater than the variation in the inlet-side flow velocity distribution D1.

[0037] Because of the large variation in the outlet velocity distribution D2 of the mixed fluid M, the position of the flame surface S formed by the flame in each mixing tube 30 also varies along the axis O. Therefore, it is possible to avoid the flame surfaces S becoming aligned along the axis, and combustion vibration can be reduced.

[0038] Furthermore, since the flow path shapes at the inlet 32 ​​of each mixing tube 30 are different, it is possible to design without adversely affecting combustion. In other words, since a flame is formed on the downstream end face 22 side of the mixing section 20, if the flow path shape on the outlet side of the mixing tube 30 is changed carelessly, problems such as flashback and NOx generation due to changes in the combustion state will occur. In contrast, in this embodiment, by avoiding changes in the shape on the downstream end face 22 side of the mixing tube 30, the occurrence of the above problems can be avoided. Furthermore, because the inlet section 32 has a bell-mouth shape, the pressure loss coefficient for the entire flow path within the mixing tube 30 can be kept low.

[0039] <Second Embodiment> Next, a second embodiment will be described with reference to Figures 7 and 8. In the second embodiment, components similar to those in the first embodiment are denoted by the same reference numerals, and detailed descriptions are omitted. As shown in Figure 7, in the second embodiment, a plenum 35 is formed within the mixing section 20 of the combustor 50, avoiding the area of ​​the mixing tube 30. Within the plenum 35, a fuel supply pipe 51 is provided along the axis O, connecting the plenum 35 to the fuel header 12 in the end cover 11.

[0040] As shown in Figure 8, fuel injection holes 36 are formed on the inner circumferential surface of each mixing tube 30, connecting the inside of the mixing tube 30 to the inside of the plenum 35. Multiple fuel injection holes 36 are formed at intervals in the circumferential direction of the mixing tube 30. The fuel injection port 36 functions as a fuel supply unit that supplies fuel F into the mixing tube 30. The fuel F introduced into the plenum 35 from the fuel header 12 via the fuel supply tube 51 passes through the fuel injection port 36 and is injected into and mixed with the air A flowing through the mixing tube 30. This generates a mixed fluid M.

[0041] In this embodiment, as in the first embodiment, each mixing tube 30 is configured to have a different pressure loss coefficient. Specifically, in the second embodiment, the mixing tube 30 includes a first mixing tube 30A whose inlet portion 32 is bell-mouth shaped, and a second mixing tube 30B whose inlet portion 32 is straight like the main tube portion 31.

[0042] As a result, the pressure loss coefficient of the first mixing tube 30A is smaller than that of the second mixing tube 30B. In other words, in the first mixing tube 30A, the bell-mouth-shaped inlet 32 ​​smoothly guides the air A, resulting in a large effective cross-sectional area. On the other hand, in the second mixing tube 30B, the air A does not flow in smoothly, resulting in a small effective cross-sectional area. Consequently, the flow velocity of the mixed fluid M flowing out of the first mixing tube 30A is greater than the flow velocity of the mixed fluid M flowing out of the second mixing tube 30B.

[0043] Thus, in this embodiment as well, the pressure loss coefficient of each mixing tube 30 is set such that the difference in flow velocity of the mixed fluid M flowing out of each mixing tube 30 is larger compared to the case where each mixing tube 30 has the same shape. Furthermore, the variation in the outlet-side flow velocity distribution D2 of the mixed fluid flowing out of each mixing tube 30 is larger than the variation in the inlet-side flow velocity distribution D1 of the air A flowing into each mixing tube 30. Therefore, similar to the first embodiment, it is possible to suppress the alignment of the flame surface S in the direction of the axis O and reduce combustion vibration.

[0044] <Other Embodiments> Although embodiments of the present invention have been described above, the present invention is not limited thereto and can be modified as appropriate without departing from the technical spirit of the invention.

[0045] For example, in this embodiment, the pressure loss coefficients of each mixing tube 30 are made different by changing the outer diameter of the outer surface 43 of the fuel nozzle 40 and the shape of the inlet portion 32 of the mixing tube 30. However, the invention is not limited to this, and various configurations may be adopted to make the pressure loss coefficients of each mixing tube 30 different from each other. For example, the first and second embodiments may be combined, and both the shape of the nozzle outer surface 43 and the inlet portion 32 of the mixing tube 30 may be different for each mixing tube 30.

[0046] Furthermore, as shown in the modified combustor 60 in Figure 9, for example, the inlet portion 32 of each mixing tube 30 may be made bell-mouth shaped, and by changing the shape of the bell-mouth, the pressure loss coefficients of the mixing tubes 30 (first mixing tube 30A, second mixing tube 30B) may be made different. For example, the inner diameter and expansion ratio of the bell-mouth shape may be changed, or the dimensions in the direction of axis O may be changed.

[0047] <Note> The combustor 3 and gas turbine 1 described in each embodiment can be understood, for example, as follows.

[0048] (1) The combustors 3, 50, and 60 according to the first embodiment include a mixing section 20 having a plurality of mixing tubes 30 that penetrate from an upstream end face 21 and a downstream end face 22 intersecting the combustor 3 axis O, and into which air A is introduced from the upstream end face 21 side, and a fuel F supply section that supplies fuel F to the air A in the mixing tubes 30 to generate a mixed fluid M, and the combustor 3 is configured such that the pressure loss coefficients of the flow paths of the mixing tubes 30 are different from each other so that the difference in the flow velocity of the mixed fluid M at the downstream end face 22 of the mixing tubes 30 is greater than when the flow paths of each mixing tube 30 have the same shape.

[0049] As a result, the flame surface S formed by each mixing tube 30 on the downstream end face 22 side is shifted in the direction of the combustor 3 axis O. This makes it possible to suppress combustion vibrations that would occur if the flame surfaces S of each mixing tube 30 were aligned in the direction of the combustor 3 axis O.

[0050] (2) The combustors 3, 50, and 60 according to the second embodiment are combustors 3, 50, and 60 of (1) wherein each of the mixing tubes 30 has an inlet portion 32 connected to the upstream end face and a main tube portion 31 connected to the inlet portion 32 and having a uniform inner diameter that extends to the downstream end face 22, and each of the mixing tubes 30 has a different flow path shape of the inlet portion 32.

[0051] Since a flame is formed on the downstream end face 22 side of the mixing section 20, if the flow path shape on the outlet side of the mixing pipe 30 is carelessly changed, problems may occur due to the change in combustion state. In this embodiment, the flow path shape of the inlet section 32 on the upstream end face 21 side of the mixing pipe 30 is changed instead of the downstream end face 22 side, so the above-mentioned problems can be avoided.

[0052] (3) The combustor 3 according to the third embodiment is a combustor 3 according to (2) in which the fuel F supply unit is a fuel nozzle 40 that supplies fuel F from a tip portion 41 inserted into the mixing pipe 30 from the upstream end face 21 side, and the outer diameter of the tip portion 41 of each fuel nozzle 40 is different from that of the other.

[0053] This makes it possible to make the flow path shapes at the inlet portions 32 of multiple mixing tubes 30 different from each other.

[0054] (4) The combustor 3 according to the fourth embodiment is the combustor 3 of (3) wherein each of the inlet portions 32 has a bell mouth shape that widens in diameter toward the upstream end face 21.

[0055] This makes it possible to maintain a low pressure loss coefficient for the entire flow path within the mixing tube 30.

[0056] (5) The combustor 50 according to the fifth embodiment is a combustor 3, 50, 60 of (2) in which the fuel supply section 36, 40 is a fuel injection hole 36 that supplies fuel F into the mixing pipe 30 from the inner circumferential surface of the mixing pipe 30, and each of the mixing pipes 30 includes a first mixing pipe 30A whose inlet section 32 has a uniform inner diameter similar to that of the main pipe section 31, and a second mixing pipe 30B whose inlet section 32 has a bell mouth shape in which the flow path widens as it approaches the upstream end face 21.

[0057] This makes it possible to maintain a low overall pressure loss coefficient within the mixing tube 30 while making the flow velocity of the mixed fluid M from each mixing tube 30 different from that of the others.

[0058] (6) The combustor 50 according to the sixth embodiment is the combustor 50 of (5) in which the bell mouth shapes of each of the second mixing tubes 30B are different from each other.

[0059] This makes it possible to make the flow path shapes at the inlet portions 32 of the multiple mixing tubes 30 different from each other.

[0060] (7) The combustors 3, 50, and 60 according to the seventh embodiment are any combustors 3, 50, and 60 such that the amount of fuel F supplied by each of the fuel supply units 36 and 40 is greater the smaller the pressure loss coefficient of each of the mixing tubes 30 is.

[0061] This makes it possible to equalize the fuel-air ratio of the mixed fluid M in each mixing tube 30.

[0062] (8) The gas turbine 1 according to the eighth embodiment is a gas turbine 1 comprising a compressor 2 that generates air A, any of the combustors 3, 50, or 60 of (1) to (7) that generate combustion gas C by burning a mixed fluid M generated by mixing fuel F with the air A compressed by the compressor 2, and a turbine 4 driven by the combustion gas C. [Explanation of Symbols]

[0063] 1 Gas Turbine 2 Compressor 3 Combustor 4 Turbines 10 Outer cylinder 11 End cover 12 Fuel Header 13 Inner cylinder 20 Mixing section 21 Upstream end face 22 Downstream end face 30 mixing tube 30A first mixing tube 30B Second mixing tube 31 Main pipe section 31a Exit opening 32 Entrance 32a Entrance opening 35 Plenum 36 Fuel injection hole 38 Support part 40 Fuel Nozzles 40A First Nozzle 40B Second Nozzle 41 Tip 42 Fuel passage 42a Tip opening 43 Outer surface of nozzle 50 Combustors 51 Fuel supply pipe 60 Combustor B1 1st group B2 2nd group R1 Inner Circumference System R2 outer system D1 Inlet side flow velocity distribution D2 Outlet side flow velocity distribution S flame surface A air F fuel M Mixed fluid C Combustion gas O axis

Claims

1. A cylindrical mixing section having multiple mixing tubes that penetrate from the upstream end face to the downstream end face, intersecting the combustor axis, and into which air is introduced from the upstream end face side, A fuel supply unit that supplies fuel to the air in the mixing tube to generate a mixed fluid, Equipped with, The pressure loss coefficients of the flow paths of the mixing tubes are configured to be different from each other such that the difference in the flow velocity of the mixed fluid at the downstream end faces of the mixing tubes is greater than when the flow paths of each mixing tube have the same shape. The mixing tube is parallel to the combustor axis at its downstream end face, and the cross-sectional shape of the mixing tube intersecting the combustor axis is uniform. In the plurality of adjacent mixing tubes in the radial direction of the mixing section, the flow velocity of the mixed fluid at the downstream end faces is configured to alternately differ. The mixing section has a first group and a second group formed by bundling the multiple mixing tubes together. The first group is arranged in an annular region centered on the combustor axis, The aforementioned multiple second groups are combustors arranged collectively on the outer periphery of the first group and spaced apart in the circumferential direction.

2. Each of the aforementioned mixing tubes is The inlet portion connected to the upstream end face, It has a main pipe section that is connected to the inlet section and has a uniformly extending inner diameter that is connected to the downstream end face, The combustor according to claim 1, wherein each of the mixing tubes has a different flow path shape at its inlet.

3. The aforementioned fuel supply unit is A fuel nozzle that supplies fuel from a tip inserted into the mixing tube from the upstream end face side, The combustor according to claim 2, wherein the outer diameters of the tips of each fuel nozzle are different from each other.

4. The combustor according to claim 3, wherein each of the inlet portions has a bell mouth shape that widens in diameter toward the upstream end face.

5. The fuel supply unit is a fuel injection port that supplies fuel into the mixing tube from the inner circumferential surface of the mixing tube, Each of the aforementioned mixing tubes is: The inlet portion of the first mixing pipe has a uniform inner diameter, similar to the main pipe portion, A second mixing tube having a bell mouth shape in which the flow path widens towards the upstream end face at the inlet, The combustor according to claim 2, including the following:

6. The combustor according to any one of claims 1 to 5, wherein the amount of fuel supplied to each of the fuel supply units is greater the smaller the pressure loss coefficient of each of the mixing tubes is.

7. A compressor that generates air, A combustor according to any one of claims 1 to 6, wherein a compressor mixes fuel with compressed air to produce a mixed fluid, and burns the resulting mixture to generate a combustion gas, A turbine driven by the aforementioned combustion gas, A gas turbine equipped with a gas turbine.

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