JP4894947B2 - Combustor and combustion method of combustor - Google Patents

Description

  The present invention relates to a combustor and a combustion method for the combustor.

  As a conventional combustor structure, for example, there is a patent document (Japanese Patent Publication No. 2004-50771, US2003 / 0152880A1). In this technique, a double cone burner having a fuel supply portion on the outer surface of a swirl body is disclosed.

Special table 2004-50771

  In the above prior art, backfire and flame stability are not considered.

  An object of the present invention is to provide a combustor and a combustion method for the combustor that can suppress backfire and perform stable combustion.

A combustion chamber for generating a combustion gas by burning a mixed gas in which combustion air and fuel are mixed; a pilot burner provided at a central portion at an inlet of the combustion chamber; and a plurality of mains disposed around the pilot burner The main burner includes a mixing chamber for generating the mixed gas, a fuel nozzle capable of supplying liquid fuel to the mixing chamber, a mixing chamber forming member for forming the mixing chamber therein, and the mixing A plurality of air holes for supplying combustion air to the mixing chamber from the outer peripheral side of the chamber forming member are provided in the mixing chamber forming member in the circumferential direction and the axial direction, and supply holes capable of supplying gaseous fuel are formed in the air hole. Set up.

  According to the present invention, it is possible to provide a combustor and a combustion method for the combustor that can suppress backfire and perform stable combustion.

The whole structure of the gas turbine plant which is embodiment of this invention is shown. The sectional view of the burner structure of the combustor which is an embodiment of the present invention is shown. Sectional drawing (III-III cross section of FIG. 2) of the air introduction hole 14 part which is a flow path of this invention is shown. Sectional drawing (IV-IV cross section of FIG. 2) of the air introduction hole 16 part which is a flow path of this invention is shown. Sectional drawing (VV cross section of FIG. 2) in the fuel supply part of the air introduction hole which is a flow path of this invention is shown. Sectional drawing in the fuel supply part of the air introduction hole which is a flow path of this invention is shown. The sectional view of the burner structure of the combustor which is an embodiment of the present invention is shown. The sectional view of the burner structure of the combustor which is an embodiment of the present invention is shown. The sectional view of the burner structure of the combustor which is an embodiment of the present invention is shown. Sectional drawing of the air introduction hole 214 part which is a flow path of this invention is shown. Sectional drawing of the air introduction hole 218 part which is a flow path of this invention is shown. The sectional view of the burner structure of the combustor which is an embodiment of the present invention is shown. Sectional drawing of the air introduction hole 314 part which is a flow path of this invention is shown. Sectional drawing of the air introduction hole 315 part which is a flow path of this invention is shown. The sectional view of the burner structure of the combustor which is an embodiment of the present invention is shown. The burner structure figure of the combustor which is embodiment of this invention is shown. The cover structural drawing of the combustor burner which is embodiment of this invention is shown. The burner assembly structure figure of the combustor which is embodiment of this invention is shown.

  A mixing chamber forming member for forming a mixing chamber for mixing combustion air and fuel is provided inside, and a flow path for supplying combustion air to the mixing chamber from the outer peripheral side is provided in the mixing chamber forming member.

  Hereinafter, embodiments of a combustor and a combustion method of the present invention will be described with reference to the drawings. First, a first embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 shows an overall configuration of a gas turbine plant according to a first embodiment of the present invention, in which a configuration of a gas turbine combustor is shown in a side sectional view. As shown in FIG. 1, a gas turbine plant mainly combusts a compressor 1 that compresses air to generate high-pressure combustion air, and a mixture of compressed air and fuel introduced from the compressor 1. A combustor 2 that generates gas and a gas turbine 3 into which combustion gas generated by the combustor 2 is introduced are provided. The compressor 1 and the gas turbine 3 are connected.

  The combustor 2 was mixed in the mixing chamber 4 with a mixing chamber 4 for mixing fuel into combustion air and a burner 11 having a mixing chamber wall 5 as a mixing chamber forming member for forming the mixing chamber 4 therein. Combustion chamber 6 that combusts mixed gas to generate combustion gas, inner cylinder 7 that forms this combustion chamber 6 inside, transition piece 8 that guides the combustion gas from this inner cylinder 7 to gas turbine 3, and these A burner 11, an inner cylinder 7, and an outer cylinder 9 in which a transition piece 8 is housed, and an ignition plug 10 that is supported by the outer cylinder 9 and ignites a mixed gas in the combustion chamber 6. With such a configuration, the compressed air from the compressor 1 is introduced into the mixing chamber 4 and mixed with fuel as indicated by the arrow a in FIG. 1, and this mixed gas is ignited by the spark plug 10 in the combustion chamber 6. Then, the combustion gas generated by the combustion is injected into the gas turbine 3 through the transition piece 8 as shown by an arrow A in FIG. 1 to drive the gas turbine 3. Thereby, the generator connected to the gas turbine 3 (not shown) is driven to generate power.

  FIG. 2 is a side sectional view showing the detailed structure of the burner 11. As shown in FIG. 2, the mixing chamber wall 5a of the mixing chamber forming member forming the mixing chamber 4 is directed toward the combustion chamber 6 (the right direction in FIG. 2, in other words, the ejection direction of the first fuel nozzle 13 described later). It has an expanded diffuser shape or a hollow conical shape, and the combustion chamber 6 has a conical shape substantially coaxial with the axial line L1 of the mixing chamber wall 5 at the substantially apex portion of the cone of the mixing chamber wall 5a. A first fuel nozzle 13 for ejecting the first fuel is provided at the upstream position. Moreover, the mixing chamber outer wall 5b is formed in a cylindrical shape, and the mixing chamber wall 5 has a plurality of stages (three in this embodiment) in the circumferential direction at a plurality of locations and in the axial center line L1 direction (hereinafter referred to as the axial direction). Air introduction holes 14, 15, 16 for introducing combustion air from the compressor 1 into the mixing chamber 4 are formed so as to be air from the upstream side in the axial direction (left side in FIG. 2). The introduction holes 14, 15 and 16 are arranged in this order. That is, flow paths such as air introduction holes 14, 15, 16 are formed in the mixing chamber forming member.

  In each of the air introduction holes 14, 15, 16, a plurality of fuel holes 17, 18, 19 for ejecting the second fuel are provided inside the air introduction holes 14, 15, 16. The fuel holes 17, 18, 19 are provided in the air introduction hole in the vicinity of the mixing chamber outer wall 5 b and communicate with the second fuel fuel manifold 12 provided in the upstream portion of the mixing chamber 4. The second fuel can be ejected in a direction substantially perpendicular to the axial center lines L2, L3, and L4 of 14, 15, and 16. This second fuel is supplied in a direction substantially perpendicular to the air flow.

  The first fuel nozzle 13 is supplied with the first fuel from the first fuel supply system 20, and the second fuel is supplied to the fuel holes 17, 18, 19 from the second fuel supply system 21. (See FIG. 1). The first fuel and the second fuel may be the same type of gaseous fuel or liquid fuel, for example, may be gaseous fuels having different calorific values, or the first fuel may be liquid fuel and the second fuel may be gaseous fuel. . Further, when only liquid fuel is supplied to the first fuel nozzle 13, when only gaseous fuel is supplied to the fuel holes 17, 18, 19, the liquid fuel is supplied to the first fuel nozzle 13 and simultaneously the gaseous fuel is supplied to the fuel holes 17. , 18, 19 may be considered in the operation of the gas turbine.

  In the first embodiment, an operation method of the gas turbine when only liquid fuel is supplied to the first fuel nozzle 13 and when only gaseous fuel is supplied to the fuel holes 17, 18, and 19 will be described below.

  The air introduction holes 14, 15, 16 are provided so that the angle at which combustion air is introduced into the mixing chamber 4 is deflected toward at least the circumferential direction of the mixing chamber wall 5. 4 is arranged so as to eject a combustion air jet or a mixed jet of gaseous fuel and combustion air toward the vicinity of the ejection position of the first fuel nozzle 13 for liquid fuel, and downstream of the mixing chamber 4. A combustion air jet or a mixed jet of gaseous fuel and combustion air is arranged along the inner peripheral surface 5 a of the mixing chamber wall 5 toward the side. Details will be described with reference to FIGS. 3 and 4 and FIG.

  FIG. 3 is a cross-sectional view of the mixing chamber wall 5 at the axial position where the air introduction hole 14 is drilled (III-III section in FIG. 2), and FIG. 4 is a diagram where the air introduction hole 16 is drilled. It is a cross-sectional view (IV-IV cross section in FIG. 2) of the mixing chamber wall 5 in the axial position.

  3 and 4, X is an offset distance between the axis L2 and L4 of the air introduction holes 14 and 16 and the axis L1 of the mixing chamber wall 5 (that is, the axis L1 and the axes L2 and L4). , D is the inner diameter of the mixing chamber wall 5 at the axial position where the air introduction holes 14 and 16 are drilled. . In the present embodiment, the circumferential angle of the air introduction holes 14, 15, 16 is changed so that X / D increases toward the downstream side in the axial direction (right side in FIG. 2) of the mixing chamber wall 5. ing. Thereby, X / D becomes small in the upstream position of the mixing chamber 4, and the combustion air ejected from the air introduction hole 14 is near the axial center line L 1 of the mixing chamber wall 5 (that is, as shown by an arrow C in FIG. 3). The liquid fuel flows toward the vicinity of the ejection position of the first fuel nozzle 13. On the other hand, X / D increases at the downstream position of the mixing chamber 4 so that the combustion air ejected from the air introduction hole 16 is along the inner peripheral surface 5a of the mixing chamber wall 5 as shown by the arrow D in FIG. Inflow.

  In the present embodiment, the axial angles of the air introduction holes 14, 15, and 16 are also changed according to the position of the axial center line L <b> 1. That is, as shown in FIG. 2, the angle α1 between the axial center line L2 and the inner peripheral surface 5a of the mixing chamber wall 5 is relatively increased for the air introduction hole 14 which is the most upstream side in the mixing chamber wall 5. (For example, the plane including the axis L2 of the air introduction hole 14 is at an angle such that the plane intersecting the axis L1 substantially perpendicularly) 16, the angle α2 between the axis L3, L4 and the mixing chamber wall inner peripheral surface 5a is relatively small (for example, about 90 °). Thereby, the combustion air from the air introduction hole 14 is combined with the effect of reducing the above-mentioned X / D with respect to the axial center line L1 (with respect to the liquid fuel ejected from the first fuel nozzle 13 of the liquid fuel. ) It flows in at a substantially right angle.

  Further, as described above, since the X / D becomes relatively large for the air introduction holes 15 and 16, the amount of deflection in the circumferential direction is large, so that the diameter of the outlet (mixing chamber 4 side) of the air introduction holes 15 and 16 is large. When the angle α1 is the same as that of the air introduction hole 14, the adjacent introduction hole outlets interfere with each other, and the number of air introduction holes 15 and 16 installed in the circumferential direction must be reduced. According to the present embodiment, it is possible to reduce the diameter of the outlet by making the angle α2 and the angle between the axial center lines L3, L4 of the air introduction holes 15 and 16 and the inner peripheral surface 5a substantially perpendicular, thereby reducing the air introduction hole 15. , 16 can be secured in the circumferential direction. With such a configuration, the mixing chamber 4 and the mixing chamber wall 5 can be made compact.

  FIG. 5 is a cross-sectional view of the mixing chamber wall 5 at the position of the fuel hole 17 formed in the air introduction hole 14 (VV cross section in FIG. 2). One fuel hole 17 is formed in one air introduction hole and perpendicular to the axis L1, and the gaseous fuel is supplied toward the center of the air introduction hole 14 as shown by an arrow O in the figure. It is configured.

  Next, the operation obtained by the first embodiment of the combustion method by the gas turbine combustor of the present invention having the above-described configuration and its fuel supply will be described in order for each item below.

(1) Action to prevent backfire of flame. In the present embodiment, when gaseous fuel is supplied from the fuel holes 17, 18, 19, the gaseous fuel is ejected from the fuel holes 17, 18, 19 toward the air introduction holes 14, 15, 16, and the gaseous fuel and compression are performed. Combustion air introduced from the machine 1 is introduced into the mixing chamber 4 through the air introduction holes 14, 15, 16. The gaseous fuel ejected from the gaseous fuel holes 17, 18, and 19 and the combustion air are sufficiently mixed in the mixing chamber 4 to form a homogeneous premixed gas and burned in the combustion chamber 6 on the downstream side of the mixing chamber 4. Thus, the combustion gas is supplied to the gas turbine 3.

  Here, for example, the air introduction holes 14, 15, 16 have a structure that is long enough to premix the gaseous fuel ejected from the gaseous fuel holes 17, 18, 19 and the combustion air, and When the diameter is reduced to the downstream side or when there is a bent portion, the self-ignition of the mixed gas in the air introduction holes 14, 15, 16, or the air introduction hole 14 from the combustion chamber 6 through the mixing chamber 4. , 15, 16, there is a risk that the flame may be held in a vortex generated in a low-velocity region or a bent portion in the upstream portion of the reduced diameter. In addition, the combustion air introduced into the combustor 2 is generated by being compressed by the compressor 1, and dust and the like are often included in the process of flowing down each flow path. For this reason, when the combustion air introduced into the air introduction holes 14, 15, 16 includes flammable dust or the like, the dust or the like becomes a fire type and the inside of the air introduction holes 14, 15, 16 is contracted. There is a risk that the flame may be held in a vortex generated in a region where the flow velocity is low in the upstream portion of the diameter or in a bent portion.

  Further, even when there is no mechanism for generating a vortex for holding a flame inside the air introduction hole, a structure such as a fuel supply unit is provided on the outer surface of the swirl body as in the comparative example (Japanese Patent Publication No. 2004-50771). Is present, this structure disturbs the flow of air around the swirl body and generates a relatively strong small vortex in the downstream direction of the structure. It is conceivable that a flame is held in the air. In particular, as in the comparative example, when there is a structure such as a fuel supply part near the air inlet of the swirl body, the vortex generated by the structure flows into the swirl body without being attenuated. Increases nature. In addition, when air flow turbulence or vortices occur at the air inlet of the swirl body, the static pressure distribution at the swirl body inlet changes, so the axial position of the air inlet that opens in the axial direction of the combustor Since the flow rate of air flowing into the swirl body is different from the design value, the fuel concentration distribution inside the swirl body may be disturbed to cause combustion vibrations, or there may be a flame return due to the combustion vibrations.

  When such a situation occurs, the mixing chamber wall 5 is deformed or broken due to overheating, and it is necessary to consider damage to the entire gas turbine plant.

  On the other hand, in the present embodiment, the air introduction holes 14, 15, 16 for mixing the combustion air and the gaseous fuel ejected from the gaseous fuel holes 17, 18, 19 and introducing them into the mixing chamber 4 are downstream. Therefore, the air introduction hole 14 may be caused by spontaneous ignition, flame return, or mixing of flammable dust into the combustion air. 15, 16, even if a flame penetrates, it does not stay in the air introduction holes 14, 15, 16, but is immediately ejected into the mixing chamber 4, so that it is possible to prevent a situation where a backfired flame is held. .

  Further, in the present embodiment, since the fuel holes 17, 18, 19 are formed inside the air introduction holes 14, 15, 16, the air flow is disturbed around the air introduction holes 14, 15, 16. Since there is no structure that generates vortices or vortices, fluctuations in the flow rate of the airflow flowing into the mixing chamber are less likely to occur, and the occurrence of flame return can be suppressed. Thus, according to the embodiment of the present invention, it is possible to suppress the backfire of the flame.

(2) NOx generation reduction action. In the present embodiment, as shown in FIG. 5, the fuel holes 17, 18, 19 are formed inside the air introduction holes 14, 15, 16 so as to be ejected in a direction substantially perpendicular to the air flow. Since the gaseous fuel ejected from the fuel hole 17 collides with the wall surface 14a of the air introduction hole 14 facing the fuel hole 17 and is dispersed, the contact area with the air flow flowing through the air introduction hole 14 increases, Is promoted.

  Further, when the fuel flow rate is increased, the fuel ejection speed is increased, so that the dispersion when the fuel collides with the wall surface 14a becomes remarkable, and the mixing with the air flow is further promoted.

  Further, in the present embodiment, the gas fuel ejected from the fuel hole 17 is ejected substantially at right angles to the air flow inside the air introduction holes 14, 15, 16. Since the diameter of the air introduction hole 14 can be made relatively small with respect to the penetration force (distance), the collision speed to the wall surface 14a is not easily attenuated, and the gaseous fuel is dispersed to promote mixing with the air flow. .

  As a result, the combustion air and the gaseous fuel introduced into the air introduction holes 14, 15, and 16 are sufficiently mixed in the air introduction holes 14, 15, and 16 (hereinafter, the combustion air and the gaseous fuel in this state are mixed together). (Hereinafter referred to as the primary mixed gas), and then jetted into the mixing chamber 4 from the air introduction holes 14, 15, 16, and mixing is promoted by the vortex generated during the jetting (hereinafter, combustion air in this state) And gaseous fuel is described as a secondary gas mixture). Note that this vortex is normally generated when the flow path expands in a step shape.

  At this time, in the present embodiment, as described above, the circumferential angle of the air introduction holes 14, 15, 16 is changed so that X / D increases toward the downstream side in the axial direction of the mixing chamber wall 5. Provide. Thereby, in the upstream position of the mixing chamber 4, the secondary mixed gas ejected from the air introduction hole 14 flows toward the vicinity of the fuel ejection position of the first fuel nozzle 13 for liquid fuel. Thereby, since the secondary combustion gases ejected from the air introduction hole 14 collide with each other at a high speed, mixing is further promoted. On the other hand, in the middle / downstream position of the mixing chamber 4, the secondary mixed gas introduced from the air introduction holes 15, 16 flows along the inner peripheral surface 5 a of the mixing chamber wall 5. As a result, a strong swirling flow is generated in the mixing chamber 4, and the secondary mixed gas ejected from the air introduction holes 15, 16 collides with the swirling flow, so that mixing is greatly promoted. In this way, the secondary mixed gas ejected from the air introduction holes 14, 15, 16 is sufficiently mixed in the mixing chamber 4.

  In the present embodiment, the length of the air introduction hole is longer in the upstream side air introduction hole, so that the upstream side air introduction hole has a larger amount of gaseous fuel and combustion air inside the air introduction hole. Primary mixing is promoted.

  On the other hand, the liquid fuel ejected from the first fuel nozzle 13 of the liquid fuel is atomized by the shearing force of the combustion air ejected from the air introduction hole 14 and colliding at a substantially right angle, and a part thereof is evaporated. Therefore, mixing with the combustion air ejected from the air introduction holes 15 and 16 while being flowed toward the downstream of the mixing chamber 4 by the swirling flow is promoted (hereinafter, this liquid fuel, gaseous fuel, and A state in which combustion air is mixed is referred to as a premixed gas).

  In this way, in the mixing chamber 4 having the same structure, the gaseous fuel and the combustion air, or the liquid fuel and the combustion air can be sufficiently mixed to generate a homogeneous premixed gas. Even if is used, the amount of NOx generated can be reduced.

(3) Anti-coking effect. According to the present embodiment, since X / D is small at the upstream position of the mixing chamber 4, the combustion air ejected from the air introduction hole 14 is near the axis L <b> 1 of the mixing chamber wall 5 as shown in FIG. 3. Therefore, a strong swirl force acts only on the central region, and the swirl flow is attenuated near the inner peripheral surface 5a of the mixing chamber wall 5 so that the swirl force becomes relatively small. For this reason, it is possible to prevent the liquid fuel droplets ejected from the first fuel nozzle 13 of the liquid fuel from colliding with the mixing chamber peripheral surface 5a due to the swirling action of the swirling flow. Therefore, the occurrence of coking can be prevented.

  In addition, a stagnation region in which small ejected liquid droplets stagnate may occur in the vicinity of the ejection position of the first fuel nozzle 13 for liquid fuel. When this stagnation region occurs, the possibility of droplets adhering to the peripheral surface 5a of the mixing chamber increases, which causes coking. According to the present embodiment, as described above, the combustion air flows from the entire circumferential direction toward the vicinity of the fuel ejection position of the first fuel nozzle 13 of the liquid fuel. Occurrence of the stagnation region that easily adheres to 5a can be suppressed. Thereby, generation | occurrence | production of coking can be prevented reliably.

  Furthermore, it is conceivable that a droplet having a relatively large particle size collides with the mixing chamber wall inner peripheral surface 5a against the swirling force of the swirling flow due to its inertial force. Since the air introduction holes 14, 15, 16 are provided over the entire circumferential direction of the peripheral surface 5 a, the droplets that try to collide with the inner peripheral surface 5 a are caused by the combustion air ejected from the air introduction holes 14, 15, 16. Can be blown away. Thereby, the occurrence of coking can be prevented more reliably.

  For example, when a pressure spray type spiral liquid fuel nozzle is used as the first fuel nozzle 13 for liquid fuel, droplets ejected from the first fuel nozzle 13 for liquid fuel are directed toward the outer periphery of the axis L1 by centrifugal force. Will erupt. Even in such a case, according to the present embodiment, as described above, the combustion air flows from the entire circumferential direction toward the vicinity of the fuel ejection position of the first fuel nozzle 13 of the liquid fuel. It is possible to suppress the droplets from spreading to the outer peripheral side, and to prevent the droplets from colliding with the mixing chamber peripheral surface 5a. Further, in this case, since the shearing force to the liquid fuel by the combustion air can be exerted to the maximum extent, it is possible to atomize the droplets and greatly promote the mixing.

(4) Improvement of combustion stability. According to the present embodiment, since there is no structure that generates turbulence or vortices in the mixing chamber outer wall 5b serving as the inlet portion of the air introduction hole, a stable air flow rate can be supplied into the mixing chamber. Therefore, combustion stability is improved.

  In addition, according to the present embodiment, the circumferential angle of the air introduction holes 14, 15, 16 is changed so that X / D becomes larger toward the downstream side in the axial direction of the mixing chamber wall 5. Thereby, X / D becomes large as the axial direction downstream position of the mixing chamber wall 5, and the premixed gas flows into the combustion region while generating a strong swirling flow in the outlet region of the mixing chamber 4. Thereby, in the exit area of the mixing chamber 4, a recirculation area is formed in the vicinity of the axial center position, and the combustion stability can be improved.

(5) Other effects. According to the present embodiment, since the fuel holes 17, 18, and 19 are integrally formed inside the air introduction holes 14, 15, and 16 of the burner 11, the outer shape of the burner 11 is cylindrical and has a compact shape. Thus, the rate of occurrence of separation vortices that cause flashback is reduced.

(6) Improved efficiency. According to the present embodiment, since the flow of combustion air becomes smooth, the pressure loss of the burner 11 can be reduced, so that the overall efficiency of the gas turbine can be improved.

  Next, a second embodiment of the gas turbine combustor of the present invention will be described with reference to FIG. FIG. 6 is a side sectional view showing a part of the air introduction hole 14 and the fuel hole 17 in the present embodiment.

  In the first embodiment, as described above, the fuel holes 17, 18, 19 are formed in the air introduction hole so as to be ejected in a direction substantially perpendicular to the air flow. The gaseous fuel thus collided with the opposing wall surface of the air introduction hole is diffused, so that the primary mixing inside the air introduction hole is greatly promoted.

  The present embodiment shown in FIGS. 6 (a) to 6 (d) is also formed so as to be ejected in a direction substantially perpendicular to the air flow, as in the first embodiment.

  In FIG. 6A, two fuel holes 17a are formed in one air introduction hole 14. Since the fuel holes 17a are formed at positions facing each other, the gaseous fuel is indicated by an arrow o in the figure. It is ejected toward the center of the air introduction hole 14.

  FIG. 6B shows a case where four fuel holes 17b are formed in one air introduction hole 14, and the fuel holes 17b are formed at positions facing each other as in the structure of FIG. 6A. The gaseous fuel is ejected toward the center of the air introduction hole 14 as indicated by an arrow in the figure.

  6 (a) and 6 (b), the number of fuel holes is increased from that in the first embodiment, so that the contact area with air is increased and mixing is promoted. 6A and 6B, the fuel holes are formed at opposing positions, and the gaseous fuel ejected from the fuel holes collides and diffuses at the center of the air hole, so that the contact area with the air Mixing is promoted with the increase of. Further, in the present embodiment, as the flow rate of the supplied fuel increases, the ejection speed ejected from the fuel holes 17a and 17b increases, so that the diffusion when the gaseous fuel collides becomes remarkable and the mixing is promoted.

  FIG. 6 (c) shows a case where two fuel holes 17c are formed in one air introduction hole 14, and the gaseous fuel is indicated by an arrow K in the figure by installing the fuel hole 17c in the vicinity of the inner wall of the air hole. The gas fuel is jetted along the wall surface of the air introduction hole so that the gaseous fuel swirls inside the air introduction hole. Since the gaseous fuel ejected from the fuel hole 17c inside the air introduction hole 14 flows down while swirling as shown by arrows in the figure, the contact time with the combustion air becomes longer and mixing is greatly promoted. . Further, in the present embodiment, the case where two fuel holes are provided in one air hole has been described as an example, but the effect of promoting mixing can be expected even when there is one fuel hole.

  6 (a), 6 (b), and 6 (c), the primary mixing is promoted by the effect of increasing the contact area and the contact time with the air flow. As a result, the secondary mixing in the mixing chamber 4 is also promoted. Therefore, the amount of NOx generated can be further reduced.

  FIG. 6D shows fuel holes 17d and 17e having different cross-sectional areas formed in the air introduction hole 14. The main gas fuel is ejected from the fuel hole 17d, and the main gas fuel and the calorific value of the fuel hole 17e are generated. It is configured to eject different sub-gas fuels.

  In petrochemical plants, various by-product fuels may be generated in the process of generating main fuel. In the gas turbine power generation facility of the plant, it is considered that the demand for using such a by-product gas as a fuel for the gas turbine combustor is increased. In the present embodiment, the main gas fuel is indicated by an arrow in the figure from the fuel hole 17d. As shown in the figure, the by-product fuel is ejected from the fuel hole 17e as shown by an arrow in the figure, and air, main fuel, and by-product fuel can be mixed inside the air introduction hole. Mixing is promoted. The cross-sectional area of the fuel hole 17e is adjusted by the flow rate of the by-product fuel, and the gas supplied to the fuel hole 17e may be nitrogen or steam, and is not limited to combustible gaseous fuel.

  Next, a third embodiment of the gas turbine combustor of the present invention will be described with reference to FIG. In this embodiment, the axial length of the mixing chamber wall is extended, and the axial arrangement of the air introduction holes is concentrated on the upstream side.

  As shown in FIG. 7, in the burner 111 of the present embodiment, the axial length is made longer while the expansion angle of the mixing chamber wall 105 is made smaller than that of the mixing chamber wall 5 in the first embodiment described above. The air introduction holes 114, 115, 116, 117, and 118 are concentrated on the upstream side of the mixing chamber wall 105. These air introduction holes 114, 115, 116, 117, and 118 are arranged so that the X / D becomes larger toward the downstream side in the axial direction of the mixing chamber wall 105 as in the first embodiment, that is, the air introduction holes. The circumferential angle is changed so that X / D is small at 114 and X / D is large at the air introduction hole 118. In the present embodiment, the air introduction holes 114, 115, 116, 117, 118 are not changed in the axial direction angle according to the position of the axial center line L 5, and the air introduction holes 114, 115, 116, 117 are not changed. , 118 and the plane including the axial center line (not shown) intersects with the axial center line L5 substantially perpendicularly.

  Further, a plurality of gaseous fuel holes 119, 120, 121, and 122 for ejecting gaseous fuel are introduced into the air introducing holes 115, 116, 117, and 118, respectively, as shown in FIG. The holes 115, 116, 117, 118 are provided so as to face each other, and the axial center lines (not shown) of the air introduction holes 115, 116, 117, 118 are provided as in the second embodiment. ) And gaseous fuel can be ejected in a direction substantially perpendicular to.

  Further, the expansion angle of the inner peripheral surface 105a of the mixing chamber wall 105 with respect to the axial center line L5 is set to be relatively small α3 on the upper and middle flow sides of the mixing chamber 4 and relatively large α4 on the downstream side, and spreads in the outlet region. The angle is formed to be large.

  According to the present embodiment configured as described above, as in the first and second embodiments described above, the effects of preventing flame inversion, reducing NOx generation, preventing coking, and improving combustion stability are achieved. Each can be obtained, and the following actions can be obtained.

(7) Further improvement of combustion stability. In the present embodiment, the mixing chamber wall 105 is formed such that the expansion angle of the inner peripheral surface 105a with respect to the axial center line L5 is larger in the outlet region. Therefore, the axial velocity of the premixed gas in this outlet region And a recirculation flow region (portion indicated by T in FIG. 5) can be formed on the outer peripheral side of the flame, and as a result, the flame holding force of the flame is increased, for example, instability in the axial direction of the flame. Vibration and the like can be prevented. Therefore, combustion stability can be further improved.

(8) Further prevention of flashback of flame. According to the present embodiment, when gaseous fuel is ejected from the gaseous fuel holes 119, 120, 121, and 122 as in the first embodiment, the upstream side of the air introduction holes 115, 116, 117, and 118. Since there is no structure that generates turbulence or vortices in the vicinity, it is possible to prevent the flame from being held in the air introduction holes 115, 116, 117, and 118. The first embodiment When a swirl flow is formed in the mixing chambers 4 and 104 as in the present embodiment, combustion occurs due to a recirculation region generated in the central portion (axial center lines L1 and L5) of the swirl flow in the mixing chamber outlet region. Stability can be improved, but in some cases the flame may return from the combustion zone into the mixing chamber 4,104.

  Here, as described in (7) above, according to the present embodiment, the combustion stability can be further improved. Therefore, even if the swirling force of the premixed gas in the outlet region is weakened, the combustion stability is improved. It is possible to hold the same level as in the first embodiment. That is, the X / D of each air inflow hole 114, 115, 116, 117, 118 is set small to weaken the swirling flow in the outlet region, and to suppress the return of the flame by weakening the formation of the recirculation region, The swirl force of the premixed gas is adjusted by adjusting the X / D and the outlet spread angle α4 in such a manner that the flame holding force of the flame is increased to maintain the combustion stability by increasing the spread angle α4 in the outlet region. And the axial speed can be adjusted to suppress the backfire of the flame from the combustion region to the inside of the mixing chamber 104 while maintaining the combustion stability. Therefore, the backfire of the flame can be further prevented.

(9) Further reduction of NOx generation amount. According to the present embodiment, the axial length of the mixing chamber wall 105 is formed to be relatively long, and the air introduction holes 114, 115, 116, 117, 118 are concentrated on the upstream side, so that the mixing chamber The mixing distance at 104 can be increased. Thereby, mixing of the secondary mixed gas (gaseous fuel and combustion air) ejected from each air inflow hole 115,116,117,118 can further be accelerated | stimulated.

  Further, even when the liquid fuel is ejected from the liquid fuel nozzle 113, the proportion of the liquid fuel ejected from the liquid fuel nozzle 113 increases as the mixing distance becomes longer, and the mixing of the liquid fuel and the combustion air also occurs. It can be further promoted to produce a more homogeneous premixed gas. Therefore, the amount of NOx generated can be further reduced.

(10) Heat suppression action of the liquid fuel nozzle. In the present embodiment, since the gaseous fuel hole is not formed in the air introduction hole 114 on the most upstream side of the mixing chamber 104, combustion air is exclusively ejected from the air introduction hole 114.

  When gas fuel is ejected from a gas fuel hole and burned, when the fuel concentration becomes low due to the start of fuel supply or a failure of the fuel supply system, a flicker phenomenon may occur in which the fire starts or disappears . When flicker occurs, the pressure inside the combustor fluctuates, and this fluctuation in pressure may cause the flame to flow back into the mixing chamber 104 and heat the inside of the mixing chamber 104 and the liquid fuel nozzle 113. In the embodiment, since the combustion air is exclusively ejected from the air introduction hole 114 closest to the liquid fuel nozzle 113, the liquid fuel nozzle 113 is cooled by the combustion air ejected from the air introduction hole 114, so that the flicker phenomenon Even if this occurs, the liquid fuel nozzle 113 can be prevented from being heated.

(11) The action of suppressing the occurrence of combustion vibrations. In this embodiment, since the mixing distance for generating the premixed gas is increased, it is possible to realize combustion characteristics that are relatively close to premixed combustion as compared with the first embodiment described above. When such premixed combustion is performed, combustion vibration in which the pressure inside the combustor 2 (that is, the pressure in the mixing chamber 104 and the combustion chamber 6) periodically changes may occur. There are several vibration modes in this combustion vibration. When a specific vibration mode is excited by the combustion state, the pressure amplitude of the combustion vibration increases. When the pressure amplitude of the combustion vibration is increased, the sliding surfaces of the parts constituting the combustor 2 are worn, so it is important to prevent the occurrence of the combustion vibration.

  In the case of the gas turbine plant as in the present embodiment, generally, when the pressure in the combustor 2 and the pressure in the gas turbine 3 become a constant pressure ratio, the flow velocity of the combustion gas is changed to the first stage stationary blade throat section 30 (FIG. 1). Reach the speed of sound. Thus, when the flow of the fluid reaches the speed of sound, it is regarded as a solid wall in which acoustic waves do not propagate acoustically. Therefore, in the present embodiment, both ends of the combustor 2 (that is, the first stage stationary blade throat portion 30 and the combustion chamber) In this case, the pressure wave is reflected between the first stage stationary blade throat 30 and the combustor 2 inlet which is the other reflection end. May be repeated to form a standing wave and increase the pressure amplitude.

  In the present embodiment, since the mixing wall 105 having a low conical shape is installed at the inlet of the combustor 2 serving as one reflection end, even if the pressure wave travels to the mixing wall 105, the pressure wave It is possible to suppress the occurrence of combustion vibration by exerting a damping action on the gas. Note that this action of suppressing the occurrence of combustion vibrations can also be obtained in the first and second embodiments described above.

  Next, a fourth embodiment of the combustion method according to the gas turbine combustor and the fuel supply method of the present invention will be described with reference to FIG. In the present embodiment, the expansion angle of the mixing chamber outlet is narrower than that of the third embodiment.

  FIG. 8 is a side sectional view showing the detailed structure of the burner according to the present embodiment. In FIG. 8, parts similar to those in FIG. 7 of the third embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 8, in the burner 111 ′ of the present embodiment, the outlet portion of the mixing chamber 104 is formed at α5 smaller than the expansion angle α3 of the mixing chamber 104, and the mixing chamber 104 of the third embodiment is formed. The cross-sectional area of the outlet portion is reduced to accelerate the outlet flow velocity of the premixed gas.

  According to the present embodiment configured as described above, flame inversion prevention, NOx generation reduction, coking prevention, combustion stability improving action, liquid fuel, as in the third embodiment described above. A nozzle overheating suppressing action and a combustion vibration suppressing action can be obtained, and the following actions can be obtained.

(12) Further reduction of NOx generation amount. In the present embodiment, the mixing chamber wall 105 is formed so that the expansion angle of the inner peripheral surface 105a with respect to the axial center line L5 becomes smaller in the outlet region, so the axial velocity of the premixed gas in this outlet region As a result, the position of the premixed flame held downstream of the mixing chamber 104 can be held downstream of the third embodiment. Therefore, since the premixing distance is increased by the amount that the flame is held downstream, the mixing of fuel and combustion air is promoted, and the amount of NOx generated can be reduced.

  Next, a fifth embodiment of the gas turbine combustor of the present invention will be described with reference to FIGS. In the present embodiment, the inner wall of the mixing chamber is formed in a hollow cylindrical shape, and the cross-sectional area of the air introduction hole on the upstream side in the axial direction is formed larger than the air introduction hole on the downstream side.

  As shown in FIG. 9, in the burner 211 of the present embodiment, the inner peripheral wall 205a of the mixing chamber wall 205 is formed in a cylindrical shape having the same diameter in the axial direction, and the air introduction hole 214 on the most upstream side is another air introduction hole. The inner diameter is larger than the holes 215, 216, 217, and 218. As shown in FIGS. 10 and 11, these air introduction holes 214, 215, 216, 217, and 218 have X / D as they go to the downstream side in the axial direction of the mixing chamber wall 205 as in the third embodiment. The circumferential angle is changed so as to increase, that is, the air introduction hole 214 has a small X / D and the air introduction hole 218 has a large X / D.

  In addition, a plurality of gaseous fuel holes 219, 220, 221, and 222 for ejecting gaseous fuel are formed inside the air introducing holes 215, 216, 217, and 218, respectively. It is provided so as to face each other, and gaseous fuel can be ejected in a direction substantially perpendicular to the axial center lines (not shown) of these air introduction holes 215, 216, 217, and 218, as in the third embodiment. It is like that.

  Further, the expansion angle with respect to the axis L5 of the inner peripheral surface 205a of the mixing chamber wall 205 is set to be relatively large α6 on the downstream side of the mixing chamber 204, and the expansion angle is increased in the outlet region. .

  According to the present embodiment configured as described above, the same operation as that of the third embodiment described above can be obtained, and the following operation can be further obtained.

(13) Reduction of burner production cost. In the present embodiment, since the inner peripheral surface 205a of the mixing chamber wall 205 has a hollow cylindrical shape, an effect of reducing the manufacturing cost can be expected as compared with the first to fourth embodiments. In addition, when the mixing chamber wall 205 is formed in a hollow cylindrical shape, unlike the first to fourth embodiments, the flow velocity on the upstream side of the mixing chamber 204 may be reduced to induce flame return. In the embodiment, by increasing the cross-sectional area of the upstream air inflow hole 214, it is possible to suppress the deceleration of the flow velocity of the premixed gas on the upstream side of the mixing chamber 204, and thus it is possible to prevent flame return. Become.

  Next, a sixth embodiment of the gas turbine combustor of the present invention will be described with reference to FIGS. In the present embodiment, a small hollow conical mixing chamber is formed inside a large hollow cylindrical mixing chamber, and an air introduction hole for introducing combustion air into each mixing chamber is formed.

  As shown in FIG. 12, in the burner 311 of this embodiment, the inner peripheral wall 305a of the second mixing chamber wall 305 is formed in a cylindrical shape, and the second mixing chamber wall 305 has the second mixing chamber 304. Air introduction holes 315, 316, 317, and 318 for introducing combustion air are formed, and a hollow conical first mixing chamber 322 smaller than the second mixing chamber 304 is formed at the upstream end of the second mixing chamber 304. , An air introduction hole 314 for introducing combustion air into the first mixing chamber 322 is formed, and a liquid fuel nozzle 313 is disposed at the upstream end of the first mixing chamber 322.

  As shown in FIG. 13, when viewed from the downstream side of the burner 311, the air introduction hole 314 for introducing the combustion air into the first mixing chamber 322 turns clockwise as indicated by an arrow C in the figure. As shown in FIG. 14, the air introduction hole 314 of the second mixing chamber 304 is swung counterclockwise as shown by an arrow S in the drawing as viewed from the downstream side of the burner 311. It is formed to do. Further, as shown in FIG. 4, the air introduction holes 315, 316, 317, and 318 formed in the second mixing chamber 304 are formed so that the swirl acts strongly.

  In addition, a plurality of gaseous fuel holes 319, 320, and 321 for ejecting gaseous fuel are respectively disposed in the air introduction holes 316, 317, and 318 so as to face the inside of the air introduction holes 316, 317, and 318, respectively. As in the fifth embodiment, gaseous fuel can be ejected in a direction substantially perpendicular to the axial center lines (not shown) of these air introduction holes 316, 317, and 318.

  Further, the expansion angle of the inner peripheral surface 305a of the mixing chamber wall 305 with respect to the axis L5 is set to be relatively large α6 on the downstream side of the mixing chamber 304, and the expansion angle is increased in the outlet region. .

  According to the present embodiment configured as described above, the same operation as that of the fifth embodiment described above can be obtained, and the following operation can be further obtained.

  In the case where liquid fuel is ejected from the liquid fuel nozzle 313, as in the first to fifth embodiments, the shear force of the airflow flowing from the air introduction hole 314 is also used in the present embodiment, and the liquid fuel nozzle 313 is used. The droplets ejected from are atomized. The atomized droplets are accompanied by the air flow flowing in from the air introduction hole 314, that is, flow down to the second mixing chamber while turning clockwise. Since the air introduction holes 315, 316, 317, and 318 provided in the second mixing chamber 304 are all formed so as to rotate counterclockwise as shown in FIG. Since the air flow swirling in the opposite directions intersects at the outlet portion of the chamber 322, a very strong shearing force acts at the boundary portion, and the droplets passing through the outlet portion of the first mixing chamber 322 are further finely divided. And the mixing with the air flow is improved, and the amount of NOx generated can be reduced.

  In addition, when the droplet sprayed from the liquid fuel nozzle 313 spreads in a conical shape, there is a possibility that it adheres to the inner peripheral surface of the first mixing chamber 322. The droplets adhering to the inner peripheral surface of the mixing chamber 322 become a liquid film and flow down to the second mixing chamber 304. However, since a strong shearing force of airflow acts on the outlet of the first mixing chamber 322, the first When the liquid film is broken and atomized at the outlet of one mixing chamber 322, the mixing with the air flow is improved and the amount of NOx generated can be reduced.

  Furthermore, if such air flow turbulence is generated in the mixing chamber, if a flame return occurs during combustion of gaseous fuel, the turbulence of the air may hold the flame and burner 311 may be burned. In the embodiment, since the fuel holes 319, 320, and 321 are formed only in the air introduction holes 316, 317, and 318 on the downstream side of the first mixing chamber 322, gaseous fuel is not supplied to the air turbulence region. There is a low possibility that the flame is held inside the second mixing chamber 304.

  In the above description, the air flow swirl directions of the first and second mixing chambers are reversed, but the same effect can be expected even if the swirl directions of the respective mixing chambers are the same.

  In the first to sixth embodiments of the present invention described above, the first fuel nozzles 13, 113, 213, and 313 for liquid fuel are not particularly described. For example, the first fuel for liquid fuel is used. As the nozzles 13, 113, 213, and 313, any spraying method such as a pressure spray type spiral nozzle (either a single orifice type or a double orifice type), a pressure spray type collision type nozzle, or a spray air type nozzle may be used. Alternatively, a liquid fuel nozzle may be used. In each embodiment, only one liquid fuel first fuel nozzle 13, 113, 213, 313 is installed. However, the present invention is not limited to this, and a plurality of liquid fuel nozzles are provided for one mixing chamber. May be provided.

  Next, a seventh embodiment of the gas turbine combustor of the present invention will be described with reference to FIG. In the present embodiment, the burner of the first embodiment is provided in the center as a pilot burner, a plurality of burners of the third embodiment are arranged around the pilot burner as a main burner, and these are combined to be a combustor Is provided.

  FIG. 15 is an enlarged side sectional view showing an inlet portion of the combustor according to the present embodiment. In FIG. 15, the same parts as those in FIGS. 2 and 7 in the first and third embodiments described above are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 15, in the present embodiment, the burner 11 shown in the first embodiment is provided at the center as a pilot burner at the inlet of the combustion chamber 6 and is shown in the third embodiment. A plurality of burners 111 are arranged around the pilot burner as a main burner. In addition, a plate 31 is provided between the outlet portion of the pilot burner 11 and the outlet portion of each main burner 111 to assist the flame holding. The liquid fuel supply system 38 is provided for the liquid fuel first fuel nozzle 13 of the pilot burner 11, the gas fuel system 39 is provided for the gas fuel holes 17, 18, and 19, and the liquid fuel nozzle 113 is provided for the liquid fuel nozzle 113 of the main burner 111. A gaseous fuel system 41 is connected to the supply system 40 and the gaseous fuel holes 119, 120, 121, 122.

  Compared with the burner 111 of the third embodiment, the burner 11 shown in the first embodiment has a relatively large expansion angle of the mixing chamber wall 5 and a short mixing distance in the axial direction. , 15, 16 are provided over the entire upper, middle, and downstream sides of the mixing chamber wall 5, so that the temperature rise of the mixing chamber wall 5 can be suppressed even when the flame approaches the mixing chamber 4. . Therefore, the ratio of the fuel (liquid fuel or gas fuel, or liquid fuel and gas fuel) flow rate to the combustion air flow rate can be set high, and stable combustion can be performed in a combustion state closer to diffusion combustion than the burner 111. Is possible. For this reason, in the present embodiment, as described above, the burner 11 is used as a pilot burner, and is used after being ignited at the time of start-up / acceleration of the gas turbine plant in which the fuel-air ratio and the combustion gas flow rate change are severe.

  On the other hand, the burner 111 of the third embodiment has a longer combustion distance in the axial direction than the burner 11 and has combustion characteristics close to that of premixed combustion, so the combustion stability range is narrowed. Therefore, in the present embodiment, as described above, the burner 111 is used as the main burner, and the gas turbine plant is ignited from a low load (a state where the start-up / acceleration is finished) when the flow rate change of the combustion air is small. When the constant load state is reached, the NOx generation amount can be reduced by operating the burner 111 so as to increase the combustion rate.

  According to the present embodiment configured as described above, by using a combination of the burner 11 and the burner 111 having different combustion characteristics, a wide load fluctuation from the start-up / acceleration of the gas turbine to a constant load region. It becomes possible to perform stable combustion over the range.

  In the seventh embodiment of the present invention, burners having different structures are used for the pilot burner and the main burner. However, the present invention is not limited to this, and burners having the same structure may be used. That is, since the burner 11 of the first embodiment can be changed from the diffusion combustion state to the premixed combustion state only by controlling the fuel flow rate, for example, the burner 11 is used for both the pilot burner and the main burner. You may do it. Also by this, it is possible to obtain the same effect as the seventh embodiment.

  Furthermore, even if the third embodiment and the fourth embodiment are mixed as a main burner, it is possible to obtain the same effect as the seventh embodiment.

  Further, as described in the first embodiment, in the seventh embodiment, there is no structure that disturbs the air flow or generates vortices upstream of the air inflow hole.

  If a structure such as a fuel supply unit is present on the outer surface of the swirl body as in the comparative example (Japanese Patent Publication No. 2004-50771), the structure may disturb the flow of air around the swirl body, Since a relatively strong small vortex is generated in the downstream direction of the object, the vortex may hold a flame inside the air introduction hole.

  In particular, as in the seventh embodiment, in the case of a multi-structure in which a plurality of swirl bodies are arranged, it is conceivable that vortices generated by the fuel supply portions of adjacent swirl bodies flow into the swirl body. For this reason, among the plurality of swirl bodies, the static pressure distribution at the inlet of a specific swirl body changes due to the influence of the generated vortex, and the flow rate of air flowing into the swirl body is different from the design value. There is a possibility that the fuel concentration distribution is disturbed and combustion vibrations occur, or that flame return occurs due to an increase in combustion vibrations.

  However, in the present embodiment, since there is no structure that disturbs the air flow or generates vortices in the vicinity of the air introduction holes of the burners 11 and 111, the occurrence of flame return can be suppressed. In addition, since the generation of vortices is small, the distribution of air flow to each burner becomes a design value, and it is possible to suppress an increase in NOx emissions and an increase in combustion vibration.

  Next, an eighth embodiment of the gas turbine combustor of the present invention will be described below with reference to FIGS.

  The present embodiment relates to a method for manufacturing a burner. The method for manufacturing the burner will be described by taking the burner 111 shown in FIG. 3 described in the third embodiment as an example.

  FIG. 16 shows the mixing chamber 105 of the burner 111, in which a hollow conical wall surface 105a expanding in the flow direction is formed. The outer peripheral wall 105b of the mixing chamber 105 has four small grooves 119a, 120a, 121a, 122a that extend in the circumferential direction and communicate with each other in the axial direction, and are orthogonal to the small grooves 119a, 120a, 121a, 122a. Large grooves 130a, 131a, 132a, 133a, 134a, 135a extending in the axial direction of the mixing chamber 105 are formed.

  Further, a nozzle installation hole 105c into which the fuel nozzle 113 is inserted is formed in the upstream side of the mixing chamber 105, and the upstream outer wall of the mixing chamber 105 is formed in an outer peripheral wall 105d smaller than the downstream outer peripheral wall 105b. In the present embodiment, the large grooves 130a, 131a, 132a, 133a, 134a, and 135a formed in the mixing chamber outer peripheral wall 105b are formed to have a larger cross-sectional area than the small grooves 119a, 120a, 121a, and 122a.

  FIG. 17 shows a cover 136 of the mixing chamber 105. A pipe 137 for supplying gas fuel to the fuel manifold 102 of the mixing chamber 105 is installed at the downstream end (left side in the figure), which matches the outer peripheral wall 105d of the mixing chamber upstream end. An insertion hole 138 is formed. Further, the inner peripheral wall 136a of the cover 136 is formed so as to coincide with the mixing chamber outer peripheral wall 105b.

  FIG. 18 shows the mixing chamber 105 shown in FIG. 16 installed with the cover 136 shown in FIG. 17 inserted from the downstream side of the mixing chamber 105. The joining points WA and WB are welded to the mixing chamber 105 and the cover. 136 is fixed. By inserting the cover 136 into the mixing chamber 105, the fuel manifold 102 is formed in the upstream portion of the mixing chamber 105, and the small grooves 119a, 120a, 121a, 122a formed in the mixing chamber outer peripheral wall 105b are large grooves 130a, 131a, 132a, The fuel manifold 102 is communicated via 133a, 134a, and 135a.

  After the mixing chamber 105 and the cover 136 are welded, air is placed in the middle in the circumferential direction of the large grooves 130a, 131a, 132a, 133a, 134a, 135a formed in the mixing chamber outer peripheral wall 105b and on the axis of the small grooves 119a, 120a, 121a, 122a. Holes 114, 115, 116, 117, 118 are formed. When the air holes are formed in the mixing chamber 105 from the outer surface of the cover 136, a cross section of a small groove formed in the mixing chamber outer peripheral wall 105b is formed inside the air hole, and the fuel holes 119, 120, 121 shown in FIG. , 122.

  As described above, since the fuel manifold 122 and the small grooves 119a, 120a, 121a, and 122a are in communication with each other, when fuel is supplied from the fuel pipe 137 to the fuel manifold 122, the fuel manifold 122 flows as indicated by arrows in FIG. For example, the fuel is supplied from the two fuel holes 119b and 119c facing the one air hole 115 and mixed with the combustion air inside the air hole 115, so that the effect described in the third embodiment can be obtained. It becomes possible.

  Further, the fuel injection speed of the fuel holes 119b and 119c is controlled by controlling the cross-sectional area of the small groove, and as shown in FIG. 5, the fuel collides with each other in the air hole and diffuses to contact the combustion air. By increasing the area, it becomes possible to promote mixing of fuel and air.

  INDUSTRIAL APPLICABILITY The present invention can provide a combustor and a combustion method for the combustor that can suppress backfire and perform stable combustion.

  DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Combustor, 3 ... Gas turbine, 4 ... Mixing chamber, 5 ... Mixing chamber wall, 6 ... Combustion chamber, 7 ... Inner cylinder, 8 ... Transition piece, 9 ... Outer cylinder, 10 ... Spark plug , 11 ... burner, 12 ... manifold, 13 ... first fuel nozzle, 14, 15, 16 ... air introduction hole, 17, 18, 19 ... fuel hole, 20 ... first fuel supply system, 21 ... second fuel supply system .

Claims (5)

A combustion chamber for generating a combustion gas by burning a mixed gas in which combustion air and fuel are mixed; a pilot burner provided at a central portion at an inlet of the combustion chamber; and a plurality of mains disposed around the pilot burner In a combustor with a burner,
The main burner includes a mixing chamber that generates the mixed gas, a fuel nozzle that can supply liquid fuel to the mixing chamber, a mixing chamber forming member that forms the mixing chamber therein, and an outer periphery of the mixing chamber forming member A plurality of air holes for supplying combustion air from the side to the mixing chamber are provided in the mixing chamber forming member in the circumferential direction and the axial direction, and supply holes capable of supplying gaseous fuel are formed in the air holes.
Combustor characterized by that. The combustor according to claim 1.
The pilot burner includes a mixing chamber that generates the mixed gas, a fuel nozzle that can supply liquid fuel to the mixing chamber, a mixing chamber forming member that forms the mixing chamber therein, and an outer periphery of the mixing chamber forming member A plurality of air holes for supplying combustion air to the mixing chamber from the side are provided in the mixing chamber forming member in the circumferential direction and the axial direction.
Combustor characterized by that. The combustor according to claim 2, wherein
A combustor, wherein a supply hole capable of supplying gaseous fuel is formed in an air hole of the pilot burner . The combustor according to claim 2 , wherein
The combustor according to claim 1, wherein the mixing chamber of the pilot burner is formed with a shorter mixing distance in the axial direction than the mixing chamber of the main burner . The combustor according to claim 2, wherein
A combustor characterized in that at least one of the mixing chamber of the pilot burner or the mixing chamber of the main burner is formed in a diffuser shape that expands from the upstream side to the downstream side of the mixing chamber .

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