JP2013145077A - Gas turbine combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine combustor capable of effectively preventing flashback.SOLUTION: A gas turbine combustor includes: flow passage formation parts 32 and 33 for forming a first flow passage part 55 (R1) in which a premixing fluid Am with fuel and combustion air mixed therein flows and a second flow passage part 55 (R2) in which a combustion fluid formed by the burnt premixing fluid Am on a downstream side of the first flow passage part 55 flows; a rotating part 53 for rotating the premixing fluid at the first flow passage part 55; and film air supply parts 11 and 56 for flowing film-like air Af along inner wall surfaces of the flow passage formation parts 32 and 33 so as to join a rotational flow of the premixing fluid Am in the first flow passage part 55. The film air supply parts have orientation adjustment parts 60 that flow the film air Af in a rotational direction corresponding to a direction of the rotational flow of the premixing fluid Am in the first flow passage part 55 (R1).

Description

  The present invention relates to a premixed gas turbine combustor.

  A premixing type gas turbine combustor is known in which fuel and compressed air are mixed in advance by a swirling flow and then burned (see, for example, Patent Document 1 (FIG. 21)). While this type of gas turbine combustor is effective in reducing NOx and the like, it is important to prevent backfire (flashback) of the main burner. In this respect, in the gas turbine combustor described in Patent Document 1, in order to suppress the occurrence of flashback due to the separation of the premixed gas, the extension pipe is inserted from the gap between the burner outer cylinder and the extension pipe downstream thereof. A film-like air (film air) is made to flow along the inner wall surface.

Japanese Patent No. 4070758

  If the film air is made to flow along the inner wall surface of the extension tube as in the gas turbine combustor described in Patent Document 1, the flow velocity in the vicinity of the inner wall surface of the extension tube can be increased. The possibility of occurrence of back can be reduced. However, simply flowing film air may cause a low-speed region in which flashback is likely to occur at the boundary between the premixed gas and the film air, and there is room for improvement in terms of preventing flashback.

  An object of the present invention is to provide a gas turbine combustor that can effectively prevent flashback.

  One aspect of the gas turbine combustor of the present invention forms a first flow path portion through which a premixed fluid in which fuel and combustion air are mixed flows, and the premixed fluid is disposed downstream of the first flow path portion. A flow path forming section that forms a second flow path section through which the combustion fluid that burns flows, a swirling section that swirls the premixed fluid in the first flow path section, and a swirling flow of the premixed fluid in the first flow path section A film air supply section for flowing film-like air along the inner wall surface of the flow path forming section, and the film air supply section is formed in a swirl direction corresponding to the swirl flow direction of the premixed fluid. It has the direction adjustment part which flows the air of.

  According to this configuration, since the film-like air flows in the swirling direction corresponding to the swirling flow of the premixed fluid, the flow of the film-like air is disturbed after the film-like air merges with the premixed fluid. Can be suppressed. For this reason, in the area | region where the density | concentration of a fuel increases, the flow rate becomes high enough, and the flashback from the combustion area | region downstream of a premixing area | region can be prevented effectively.

  In the gas turbine combustor according to another aspect of the present invention, the direction adjusting unit causes the film-like air to flow in the direction of the swirling flow of the premixed fluid.

  According to this configuration, the film-like air becomes a swirl flow that matches the swirl flow direction of the premixed fluid, and flashback from the combustion region can be effectively prevented.

  In the gas turbine combustor according to another aspect of the present invention, the flow path forming portion includes a first tubular portion and a second tubular portion disposed with a gap radially outward from the outer peripheral surface of the first tubular portion. And a film air supply part flows film-like air along the inner peripheral surface of the second cylinder part from the radial gap between the first cylinder part and the second cylinder part.

  According to this structure, film-like air is supplied over the perimeter of a 1st flow-path part from the radial direction gap between a 1st cylinder part and a 2nd cylinder part. Since the film-like air flow direction corresponds to the swirl flow direction of the premixed fluid, flashback from the combustion region can be effectively prevented.

  In the gas turbine combustor according to another aspect of the present invention, the direction adjusting portion includes a plurality of circumferential wing portions arranged in a radial gap between the first cylindrical portion and the second cylindrical portion.

  According to this configuration, the flow direction of the film-like air can be efficiently changed by the wing portion in a direction corresponding to the swirl flow direction of the premixed fluid.

  In the gas turbine combustor according to another aspect of the present invention, the direction adjusting portion has a through hole that guides air from a radially outer side of the second cylindrical portion to a radial gap between the first cylindrical portion and the second cylindrical portion. The through hole is formed obliquely corresponding to the swirling direction of the premixed fluid.

  According to this configuration, the flow direction of the film-like air can be easily changed by the through hole in a direction corresponding to the swirl flow direction of the premixed fluid.

  In the gas turbine combustor according to another aspect of the present invention, the flow path forming portion has a flow area of a radial gap between the first cylindrical portion and the second cylindrical portion at the outlet side end of the film-like air. The sum of the flow passage area of the first flow passage portion radially inward of the radial gap is equal to or larger than the flow passage area of the first flow passage portion on the downstream side of the outlet side end of the film-like air. In this way, the first flow path part and the second flow path part are formed.

  According to this configuration, the flashback can be prevented by adjusting the relationship between the upstream and downstream flow path areas of the film-like air outlet side end.

  According to the present invention, flashback from the combustion region can be effectively prevented.

FIG. 1 is a schematic configuration diagram of a gas turbine having a gas turbine combustor according to an embodiment of the present invention. FIG. 2 is an enlarged view of the combustor of FIG. FIG. 3 is a diagram schematically showing the internal configuration of the combustor of FIG. FIG. 4 is a diagram for explaining the reason for the occurrence of flashback. FIG. 5 is a diagram showing a main configuration of the gas turbine combustor according to the first embodiment of the present invention. FIG. 6 is a diagram showing the wind direction adjusting plate of FIG. FIG. 7 is a characteristic diagram of the gas turbine combustor according to the first embodiment. FIG. 8 is a diagram illustrating a comparative example of FIG. FIG. 9 is a diagram showing a modification of FIG. FIG. 10 is a diagram showing another modification of FIG. FIG. 11 is a diagram showing a main configuration of a gas turbine combustor according to the second embodiment of the present invention. FIG. 12 is a characteristic diagram of the gas turbine combustor according to the second embodiment. FIG. 13 is a diagram showing a modification of FIG.

(First embodiment)
Hereinafter, a gas turbine combustor according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a gas turbine having a gas turbine combustor according to the present embodiment.

  As shown in FIG. 1, the gas turbine includes a compressor 11, a gas turbine combustor (hereinafter referred to as a combustor) 12, a turbine 13, and an exhaust chamber 14 in order from the upstream side in the fluid flow direction. Have. A generator (not shown) is connected to the turbine 13. The gas turbine includes a rotor (turbine shaft) 24 that can rotate about a rotation axis L.

  The compressor 11 has an air intake 15 for taking in air, and a plurality of stationary blades 17 and moving blades 18 are alternately arranged in a compressor casing 16. The combustor 12 is combustible by supplying fuel to the compressed air (combustion air) compressed by the compressor 11 and igniting it with a burner. In the turbine 13, a plurality of stationary blades 21 and moving blades 22 are alternately arranged in a turbine casing 20. The exhaust chamber 14 has an exhaust diffuser 23 that is continuous with the turbine 13. The rotor 24 is positioned so as to penetrate the radial center of the compressor 11, the combustor 12, the turbine 13, and the exhaust chamber 14. An end portion of the rotor 24 on the compressor 11 side is supported by the bearing portion 25 so as to be rotatable about the rotation axis L, and an end portion on the exhaust chamber 14 side is rotated about the rotation axis L by the bearing portion 26. It is supported freely. A plurality of disk plates are fixed to the rotor 24, and the rotor blades 18 and 22 are connected to each other. A drive shaft of a generator (not shown) is connected to the end of the rotor 24 on the exhaust chamber 14 side.

  In such a gas turbine, the air taken in from the air intake port 15 of the compressor 11 passes through the plurality of stationary blades 21 and the moving blades 22 and is compressed into high-temperature / high-pressure compressed air. This compressed air is combusted in the combustor 12 by supplying predetermined fuel to the compressed air. The high-temperature and high-pressure combustion gas that is the working fluid generated in the combustor 12 passes through the plurality of stationary blades 21 and the moving blades 22 that constitute the turbine 13, and rotates the rotor 24. As a result, the generator connected to the rotor 24 is driven. The exhaust gas that has passed through the rotor 24 is converted into static pressure by the exhaust diffuser 23 in the exhaust chamber 14 and then released to the atmosphere.

  FIG. 2 is an enlarged view of the combustor 12. The combustor 12 has a combustor casing 30. The combustor casing 30 has an inner cylinder 32 disposed inside the outer cylinder 31 and a tail cylinder 33 connected to the tip of the inner cylinder 32, and has a central axis S inclined with respect to the rotation axis L. Extending along.

  The outer cylinder 31 is fastened to the vehicle compartment housing 27. The base end of the inner cylinder 32 is supported by the outer cylinder 31, and is arranged inside the outer cylinder 31 at a predetermined interval from the outer cylinder 31. A pilot burner 40 is disposed along the central axis S at the center of the inner cylinder 32. A plurality of main burners 50 are arranged around the pilot burner 40 at equal intervals and in parallel with the pilot burner 40 so as to surround the pilot burner 40. The tail tube 33 has a base end formed in a cylindrical shape and is connected to the tip of the inner tube 32. The transition piece 33 is formed to have a small cross-sectional area and bend toward the tip side, and is open toward the first stage stationary blade 21 of the turbine 13. The transition piece 33 forms a combustion chamber inside.

  FIG. 3 is a diagram schematically showing the internal configuration of the combustor 12 (mainly the inner cylinder 32). The pilot burner 40 includes a pilot cone 41, a pilot nozzle 42 disposed inside the pilot cone 41 and along the center axis S, and a pilot swirler 43 provided on the outer periphery of the pilot nozzle 42. The main burner 50 includes a burner cylinder 51, a main nozzle 52 disposed inside the burner cylinder 51 and parallel to the central axis S, and a main swirler 53 provided on the outer peripheral portion of the main nozzle 52. Fuel is supplied to the pilot nozzle 42 from a pilot combustion line (not shown) via a fuel port 44 (FIG. 2). Fuel is supplied to the main nozzle 52 from a main fuel line (not shown) via a fuel port 54 (FIG. 2).

  In FIG. 2, the high-temperature and high-pressure compressed air from the compressor 11 flows into the passenger compartment 34 around the combustor 12. The compressed air flows outside the tail cylinder 33 and the inner cylinder 32 from the tail cylinder 33 side to the inner cylinder 32 side, and flows into the inner cylinder 32 from the base end side of the inner cylinder 32. The compressed air that has flowed into the inner cylinder 32 is mixed with fuel by the pilot burner 40 and the main burner 50 and burns to become combustion gas.

  That is, the compressed air that has flowed into the inner cylinder 32 is swirled by the main swirler 53 of FIG. 3, mixed with the fuel injected from the main nozzle 52, and flows into the tail cylinder 33 as a swirling flow of premixed air. Separately, the compressed air flowing into the inner cylinder 32 is swirled by the pilot swirler 43 and mixed with the fuel injected from the pilot nozzle 42. The mixed air is ignited and burned by a not-illustrated seed fire, and is burned into the tail cylinder 33 as combustion gas. At this time, a part of the combustion gas is ejected so as to diffuse into the tail tube 33 with a flame. As a result, the premixed gas flowing into the tail cylinder 33 from the burner cylinder 51 of each main burner 50 is ignited and burned.

  In this way, flame diffusion for stable combustion of the lean premixed fuel from the main nozzle 52 can be performed by performing diffusion flame with the fuel injected from the pilot nozzle 42. Further, by premixing the fuel and compressed air from the main nozzle 52 with the main burner 50, the fuel concentration is made uniform and NOx can be reduced. At this time, the inside of the main burner 50 becomes the premixing region R1, and the region where the premixed gas burns by the diffusion flame from the pilot burner 40 becomes the combustion region R2. The combustion region R <b> 2 is downstream of the pilot cone 41 and inside the tail cylinder 33. Therefore, the combustion gas combusted by the premixed gas flows inside the tail cylinder 33. When the inner cylinder 32 extends from the tail cylinder 33 side, the combustion region R2 starts from the inside of the inner cylinder 32.

  By the way, in such a premixing type combustor 12, the premixed gas flowing in the burner cylinder 51 becomes a swirling flow downstream of the main swirler 53. For this reason, flashback from the combustion region to the premixing region is likely to occur. FIG. 4 is a diagram for explaining the reason for the occurrence of flashback. The characteristic f1 in the figure indicates the velocity distribution of the premixed gas as the swirling flow in the internal passage 55 inside the burner cylinder 51, and the characteristic f2 indicates the fuel concentration distribution. The characteristics f1 and f2 represent the velocity component and the concentration component in the direction parallel to the axis L1 of the internal passage 55, respectively. The axis L1 is substantially parallel to the central axis S (FIG. 3) of the combustor 12.

  The fuel is made uniform throughout the passage by the swirling flow. For this reason, as indicated by the characteristic f2, the fuel concentration distribution is substantially constant from the central portion of the internal passage 55 to the wall surface portion (the inner peripheral surface of the burner cylinder 51). On the other hand, as shown in the characteristic f1, the velocity of the premixed gas becomes 0 on the wall surface, and the velocity increases as the distance from the wall surface increases (velocity boundary layer), and the outside of the velocity boundary layer (the central portion side of the internal passage 55). ) Makes the speed almost constant. That is, while a velocity boundary layer having a low velocity exists in the vicinity of the wall surface (region A), the fuel concentration is high in the region A, so that flashback from the combustion region is likely to occur in the region A. As a result, the inner wall surface of the burner cylinder 51 becomes hot and the combustor 12 may be damaged. In order to avoid this, in the present embodiment, the main burner 50 is configured as follows.

  FIG. 5 is a diagram illustrating a schematic configuration of the main burner 50 according to the first embodiment. The burner cylinder 51 includes a first burner cylinder 511 and a second burner cylinder 512. The tip end portion 511a of the first burner cylinder 511 extends further to the downstream side in the flow direction of the premixed gas than the main nozzle 52. The base end portion 512a of the second burner cylinder 512 is disposed outside the distal end portion 511a so as to cover the distal end portion 511a with a gap Δd from the distal end portion 511a in the radial direction. That is, the inner peripheral surface of the base end portion 512 a of the second burner cylinder 512 is larger in diameter than the outer peripheral surface of the distal end portion 511 a of the first burner cylinder 511, and the outer peripheral surface of the first burner cylinder 511 and the second burner cylinder 512 An annular passage (annular passage 56) is formed between the inner peripheral surface of each of the two.

  One end of the annular passage 56 communicates with the vehicle compartment 34, and the other end communicates with the internal passage 55. Therefore, a part of the compressed air flowing into the vehicle compartment 34 passes through the annular passage 56 to become film-like air (film air Af) and flows along the inner peripheral surface of the second burner cylinder 512. This film air Af merges with the premixed gas Am flowing in the internal passage 55 downstream of the outlet 56 a of the annular passage 56.

  The radial gap Δd between the distal end portion 511a of the first burner tube 511 and the proximal end portion 512a of the second burner tube 512 is constant in the circumferential direction, and the annular passage 56 has a plurality of wind directions at equal intervals in the circumferential direction. An adjustment plate 60 is provided. The wind direction adjusting plate 60 is a rectangular plate member with a predetermined thickness having a height corresponding to the gap Δd, for example, and one end in the height direction is fixed to the outer peripheral surface of the first burner cylinder 511, and the other in the height direction. The end is fixed to the inner peripheral surface of the second burner cylinder 512. The air direction adjusting plate 60 is provided so as to be inclined with respect to the axis L1 of the internal passage 55 so that the flow direction of the film air Af at the outlet 56a of the annular passage 56 coincides with the turning direction of the premixed air Am at the outlet 56a. The film air Af is swirled by the wind direction adjusting plate 60.

  FIG. 6 is a diagram showing the wind direction adjusting plate 60 in the annular passage 56 developed on a plane. The swirling direction of the premixed air Am is inclined by an angle θ1 with respect to the axis L1, and the wind direction adjusting plate 60 is provided by being inclined by an angle θ2 with respect to the axis L1. For example, the angle θ1 and the angle θ2 are the same. Thereby, the film air Af flows out from the annular passage 56 in the same direction as the turning direction of the premixed air Am. That is, the film air Af flows along the inner peripheral surface of the second burner cylinder 512 as a swirling flow.

  When the flow direction of the film air Af is matched with the flow direction of the premixed gas Am in this manner, the flow of the premixed gas Am toward the outside in the radial direction is blocked by the film air Af. Therefore, the premixed gas Am can be prevented from entering the layer of the film air Af, and the premixed gas Am can be prevented from reaching the inner peripheral surface of the second burner cylinder 512. On the other hand, for example, when the turning angle θ2 of the film air Af is 0 degree, that is, when the film air Af is not a turning flow, the premixed air Am easily enters the layer of the film air Af, and the flow of the film air Af is Disturbed. As a result, in the vicinity of the inner wall surface of the second burner cylinder 512, the film air Af and the premixed gas Am are mixed to generate a mixed flow.

  7 and 8 are diagrams for explaining the axial flow after the premixed gas Am and the film air Af are merged on the downstream side of the outlet 56a of the annular passage 56. FIG. FIG. 7 shows the flow when the inclination angle θ2 of the wind direction adjusting plate 60 is made to coincide with the turning angle θ1 of the premixed air Am, and FIG. 8 shows the flow when the angle θ2 is 0 degree as a comparative example. Show. Note that the characteristics f1 and f2 in the figure show the velocity distribution and the concentration distribution, respectively, as in FIG.

  When the inclination angle θ2 of the airflow direction adjusting plate 60 is made to coincide with the turning angle θ1 of the premixed air Am, the flow of the premixed air Am outward in the radial direction is blocked by the film air Af and in the vicinity of the inner wall surface of the second burner cylinder 512 Mixing of the premixed air Am and the film air Af is suppressed. Therefore, as shown by the characteristic f2 in FIG. 7, the fuel concentration in the vicinity of the inner wall surface of the second burner cylinder 512, that is, in the layer of the film air Af is 0, and the fuel concentration is outside the layer of the film air Af. An increasing concentration boundary layer results.

  On the other hand, the speed is 0 on the inner wall surface of the second burner cylinder 512 as shown by the characteristic f1 in FIG. 7, and a speed boundary layer is generated on the inner side in the radial direction. The velocity boundary layer is thin because the flow directions of the premixed gas Am and the film air Af are equal to each other, and the velocity boundary layer is within the range where the fuel concentration is zero. Therefore, the flow rate is sufficiently high in the range where the fuel concentration increases, and thus flashback can be prevented. That is, since the region where the fuel concentration increases (region of the concentration boundary layer) and the region where the flow velocity is low (region of the velocity boundary layer) are different from each other, flashback can be effectively suppressed.

  On the other hand, when the inclination angle θ2 of the wind direction adjusting plate 60 is 0 degree, the premixed air Am enters the layer of the film air Af, and in the vicinity of the inner wall surface of the second burner cylinder 512, the film air Af and the premixed air Am Of mixed flow occurs. Therefore, as shown by the characteristic f2 in FIG. 8, a concentration boundary layer region is generated in the vicinity of the inner wall surface of the second burner cylinder 512. On the other hand, regarding the speed, the flow of the film air Af is disturbed in the region where the premixed air Am and the film air Af merge, and as shown in the characteristic f1 of FIG. 8, the premixed air Am and the film air Af The speed is reduced at the boundary portion, and a speed deficit portion v1 is generated in the vicinity of the inner wall surface of the second burner cylinder 512. Therefore, in the internal passage 55 immediately after the outlet 56a of the annular passage 56, there is a region where the fuel concentration is relatively high and the flow velocity is low, and as a result, flashback may occur.

  As described above, in the present embodiment, the wind direction adjusting plate 60 is disposed in the annular passage 56 between the first burner cylinder 511 and the second burner cylinder 512 at equal intervals in the circumferential direction, and the premixed air Am in the internal passage 55 is disposed. The film air Af was caused to flow from the annular passage 56 in a direction that coincided with the turning direction. As a result, a velocity boundary layer is generated in the vicinity of the inner wall surface of the second burner cylinder 512, and a concentration boundary layer is formed radially inward of the velocity boundary layer. Therefore, since the flow rate is sufficiently high in the region where the fuel concentration increases, flashback can be reliably prevented. Since the flow directions of the film air Af and the premixed air Am are the same, the flow of the film air Af along the inner wall surface of the second burner cylinder 512 is not disturbed. It can also be cooled.

  In the first embodiment described above, the flow direction of the film air Af is set by the wind direction adjusting plate 60. That is, the airflow is adjusted so that the film air Af flows in a predetermined direction by the wind direction adjusting plate 60, but the air direction adjusting plate 60 may be configured by the wing portion 61. FIG. 9 is a diagram schematically showing an example thereof. 9 shows a cross-sectional view of the annular passage 56 cut along a cut surface parallel to the axis L1 of the internal passage 55 on the lower side, and a development view in which the wing portion 61 is developed on the upper side.

  In FIG. 9, a cylinder 57 is disposed inside the burner cylinder 51, and an internal passage 55 is formed inside the cylinder 57. The cylindrical body 57 includes a tapered portion 571 that reduces the diameter of the internal passage 55, and a straight portion 572 that is connected to the tapered portion 571 and extends in parallel with the burner cylinder 51. The end of the taper portion 571 is joined to the inner peripheral surface of the burner cylinder 51 over the entire circumference, and an annular passage 56 is formed between the burner cylinder 51 and the cylinder 57.

  A plurality of air introduction holes 58 are opened at equal intervals in the circumferential direction so that the passenger compartment 34 and the annular passage 56 communicate with each other in the burner cylinder 51, and the blade portion 61 is disposed in the annular passage 56 downstream of the air introduction hole 58. Has been. Thus, compressed air is introduced into the annular passage 56 from the casing 34 outside the burner cylinder 51 through the air introduction hole 58. The introduced air passes between the wing parts 61, becomes film air, flows out from the outlet 56 a of the annular passage 56, and flows along the inner wall surface of the burner cylinder 51. In the configuration having the first burner cylinder 511 and the second burner cylinder 512 as shown in FIG. 5, for example, a tapered portion 571 and a straight portion 572 are formed at the end of the first burner tube 511, and a taper is formed. By joining the end portion of the second burner cylinder 512 to the base end portion of the portion 571, an annular passage 56 similar to that in FIG. 9 can be configured.

  As shown in FIG. 9, the wing part 61 includes a straight part 611 and a curved part 612 along the air flow direction. The straight line portion 611 is parallel to the axis L1, and the curved surface portion 612 is smoothly bent toward the turning direction of the premixed gas. As a result, the film air Af flowing out from the annular passage 56 swirls in the same direction as the premixed air Am along the inner wall surface of the burner cylinder 51, thereby preventing flashback from the combustion region R2 (FIG. 3). be able to. If the wind direction adjusting plate 60 is constituted by the wing portion 61, the pressure loss of the film air Af in the annular passage 56 can be reduced.

  FIG. 10 is a diagram showing a modification of FIG. In FIG. 10, the blade portion 61 is omitted, and the air introduction hole 58 is formed obliquely with respect to the thickness direction of the burner cylinder 51. That is, the outlet portion 582 of the air introduction hole 58 on the inner peripheral surface is formed to be shifted in accordance with the swirling direction of the premixed air Am with respect to the inlet portion 581 of the air introduction hole 58 on the outer peripheral surface of the burner cylinder 51. . As a result, the film air Af introduced from the air introduction hole 58 swirls in the annular passage 56 and flows out from the annular passage 56 while swirling in the same direction as the premixed air Am in the inner passage 55, thereby preventing flashback. it can. In the example of FIG. 10, since the wing | blade part 61 becomes unnecessary, a structure can be simplified. In FIG. 10, the wing portion 61 is omitted by forming the air introduction hole 58 obliquely, but the air introduction hole 58 is formed obliquely and the wing portion 61 similar to that of FIG. 9 is provided in the annular passage 56. You may do it.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIGS. The second embodiment differs from the first embodiment in the configuration of the main burner 50. FIG. 11 is a diagram schematically showing the configuration of the main burner 50 in the gas turbine combustor according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same location as FIG. 5, and the difference with FIG. 5 is mainly demonstrated below.

  In FIG. 11, unlike FIG. 5, the wind direction adjusting plate 60 in the annular passage 56 between the first burner cylinder 511 and the second burner cylinder 512 is omitted. Further, in FIG. 11, the passage area S1 of the internal passage 55 on the upstream side of the outlet 56a of the annular passage 56 and the passage area S2 of the whole annular passage 56, and the passage area S0 of the internal passage 55 on the downstream side of the outlet 56a of the annular passage 56 are shown. The relationship of S0 ≦ S1 + S2 is established. That is, in the second embodiment, the internal passage 55 is narrowed on the downstream side of the outlet 56a of the annular passage 56 instead of turning the film air Af into a swirl flow. Here, the downstream side is a region where a speed decrease is likely to occur at the boundary between the film air Af in the annular passage 56 and the premixed air Am in the internal passage 55, that is, a region where the speed deficit portion v1 in FIG. For example, the region immediately after the outlet 56 a of the annular passage 56.

  Characteristics f1 and f2 in FIG. 12 are diagrams showing a concentration distribution and a velocity distribution on the downstream side 56a of the outlet of the annular passage 56 by the gas turbine combustor according to the second embodiment, respectively. Compared with FIG. 8, the characteristic f1 of the density distribution of FIG. 12 is substantially equal to the characteristic f1 of FIG. On the other hand, with respect to the velocity distribution, in the second embodiment, the inner wall surface of the second burner cylinder 512 is formed with a diameter reduced inward in the radial direction of the internal passage 55, so the characteristic f2 in FIG. Compared with the characteristic f2, the speed in the vicinity of the inner wall surface of the second burner cylinder 512 is increased. Accordingly, a decrease in speed at the boundary between the film air Af and the premixed gas Am is suppressed, and in the characteristic f2 in FIG. 12, the occurrence of a noticeable speed defect part v1 as shown in the characteristic f2 in FIG. 8 is suppressed. Yes.

  As a result, on the downstream side of the outlet 56a of the annular passage 56, the flow velocity increases in a region in the vicinity of the wall surface where the fuel concentration increases, so that occurrence of flashback from the combustion region R2 can be suppressed. Even if the area of the internal passage 55 on the downstream side of the outlet 56a of the annular passage 56 is reduced in this way, the effect of suppressing flashback can be obtained. However, as shown in FIG. If the wind direction adjusting plate 60 is arranged, the effect of suppressing the flashback is greater. Therefore, it is more preferable not only to restrict the internal passage 55 but also to arrange the air direction adjusting plate 60 in the annular passage 56.

(Modification)
In the above embodiment, the film air Af is caused to flow from the outlet 56a of the annular passage 56 toward the swirling direction of the premixed air Am, but the biting of the premixed air Am into the film air Af can be blocked. If so, it is not necessary to strictly match the turning direction of the film air Af with the turning direction of the premixed air Am. For example, if the turning angle θ2 of the film air Af is set to be about 2 to 3 degrees larger than the turning angle θ1 of the premixed air Am, the biting of the premixed air Am may be easily blocked. It may be larger than θ1.

  In the above embodiment (FIGS. 5, 9, 10, and 13), the film air Af is swirled by the wind direction adjusting plate 60, the blade portion 61, and the air introduction hole (through hole) 58. The configuration of the direction adjusting unit is not limited to that described above as long as the film-like air Af is flowed in the swirling direction corresponding to the swirling flow direction of Am to prevent flashback. In other words, the present invention has the greatest feature in that the film air Af is rectified so as to prevent flashback, unlike the case of merely supplying film air for cooling along the inner wall surface of the combustor. As long as this feature can be realized, the direction adjusting unit may have any configuration.

  The inner cylinder 32 forms an internal passage 55 (first flow path portion) through which premixed gas (premixed fluid) Am in which fuel and combustion air are mixed, and the tail cylinder 33 allows the premixed gas Am to be The internal passage 55 (second flow path portion) through which the burned combustion gas (combustion fluid) flows is formed, but the configuration of the flow path forming portion is not limited to this. Although the premixed gas Am is swirled by the main swirler 53, the swirl portion may have any configuration.

  In the embodiment (FIG. 5), the first burner tube 511 (first tube portion) and the second burner tube 512 (first tube) arranged with a gap Δd radially outward from the outer peripheral surface of the first burner tube 511. 2), an annular passage 56 is formed, the compressed air in the passenger compartment 34 that has passed through the compressor 11 is guided to the annular passage 56, and the film is formed from the annular passage 56 along the inner wall surface of the second burner cylinder 512. If air is allowed to flow, but the film air Af is allowed to flow along the inner wall surface of the flow path forming portion so as to merge with the swirling flow of the premixed air Am in the premixing region R1, the configuration of the film air supply portion Can be anything.

  In the above embodiment (FIG. 11), the flow area S2 of the second burner cylinder 512 is reduced on the downstream side of the outlet 56a of the annular passage 56, but the first burner cylinder 511 at the outlet side end of the film air Af. The sum of the flow path area S2 of the radial gap Δd between the first burner cylinder 512 and the flow path area S1 of the internal passage 55 radially inward of the radial gap Δd is the outlet side of the film air Af. If the 1st burner cylinder 511 and the 2nd burner cylinder 512 are formed so that it may become more than channel area S0 of internal passage 55 in the downstream of premixed gas Am rather than an end, composition of a channel formation part Can be anything.

  In the above, the combustor 12 is applied to a gas turbine for power generation. However, the gas turbine combustor of the present invention can be applied to other gas turbines as well.

  The above description is merely an example, and the present invention is not limited to the above-described embodiments and modifications unless the features of the present invention are impaired. The constituent elements of the embodiment and the modified examples include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. That is, other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. Moreover, it is also possible to arbitrarily combine one or more of the above-described embodiments and modified examples.

DESCRIPTION OF SYMBOLS 11 Compressor 12 Combustor 30 Combustor casing 32 Inner cylinder 33 Transition cylinder 34 Cabin 50 Main burner 51 Burner cylinder 52 Main nozzle 53 Main swirler 55 Internal passage 56 Annular passage 56a Outlet 57 Cylindrical body 58 Air introduction hole 60 Wing 511 First burner tube 512 Second burner tube Af Film air Am Premixed gas R1 Premixed region R2 Combustion region S0 Passage area S1 Passage area S2 Passage area

Claims (6)

A first flow path portion in which a premixed fluid in which fuel and combustion air are mixed flows, and a second flow path in which a combustion fluid in which the premixed fluid combusts flows downstream of the first flow path portion. A flow path forming part for forming a part;
A swirl unit that swirls the premixed fluid in the first flow path unit;
A film air supply section for flowing film-like air along the inner wall surface of the flow path forming section so as to merge with the swirling flow of the premixed fluid in the first flow path section,
The gas air combustor includes a direction adjusting section for flowing the film-like air in a swirling direction corresponding to a swirling flow direction of the premixed fluid in the first flow path section. . The gas turbine combustor according to claim 1.
The gas turbine combustor, wherein the direction adjusting unit causes the film-like air to flow in a direction of a swirling flow of the premixed fluid. The gas turbine combustor according to claim 1 or 2,
The flow path forming portion includes a first tube portion and a second tube portion disposed with a gap radially outward from the outer peripheral surface of the first tube portion,
The film air supply section allows the film-like air to flow along an inner wall surface of the second cylinder section from a radial gap between the first cylinder section and the second cylinder section. Turbine combustor. The gas turbine combustor according to claim 3.
The gas turbine combustor, wherein the direction adjusting portion includes a plurality of circumferentially disposed blade portions disposed in a radial clearance between the first tube portion and the second tube portion. The gas turbine combustor according to claim 3 or 4,
The direction adjusting portion has a through hole that guides air from a radially outer side of the second tube portion to a radial gap between the first tube portion and the second tube portion, A gas turbine combustor characterized in that the gas turbine combustor is formed obliquely corresponding to the swirling direction of the premixed fluid. The gas turbine combustor according to any one of claims 3 to 5,
The flow path forming portion includes a flow area of a radial gap between the first cylindrical portion and the second cylindrical portion at an outlet side end portion of the film-like air, and a radial direction with respect to the radial gap. The first flow path area of the first flow path section on the inner side is equal to or larger than the flow path area of the first flow path section on the downstream side of the outlet side end of the film-like air. A gas turbine combustor that forms a flow path portion and the second flow path portion.

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