JP5156066B2 - Gas turbine combustor - Google Patents

Description

  The present invention is a gas comprising a plurality of combustors for supplying a combustion gas generated by combustion of a mixture of fuel and air to a turbine, an ignition plug, and a flame propagation tube for propagating a flame between the combustors. It relates to a turbine combustor.

As a gas turbine combustor provided in a gas turbine that has been generally adopted, a gas turbine combustor having a plurality of can-type combustors is known. Each combustor reacts fuel and compressed air. The high-temperature and high-pressure combustion gas for rotationally driving the turbine is generated (see, for example, Patent Document 1).
The plurality of combustors are arranged on a circle along the circumferential direction of the turbine rotor. Combustors adjacent in the circumferential direction are connected to each other by a connecting pipe, and a flame propagation pipe is installed inside the connecting pipe. ing. The flame propagation tube is tubular, and the combustion gas passes through the flame propagation tube due to the pressure difference of the connected combustors.

  At startup, the gas turbine is driven by an external drive to increase the rotational speed to the ignition rotational speed, and then fuel and air are introduced into all combustors. Combustion is started by sparking spark plugs installed in one or two combustors. Since combustion gas in the combustor generates high-temperature combustion gas, the pressure inside the combustor rises. When the adjacent combustor is in an unignited state, a high-temperature combustion gas flows into the unignited combustor through the flame propagation tube due to a differential pressure with the ignited combustor. Thus, starting with ignition of only one or two combustors, each adjacent combustor is ignited and all combustors are ignited.

Japanese Patent No. 3940705

By the way, the burner included in each of the plurality of combustors constituting the gas turbine combustor includes a mixing chamber wall and a fuel nozzle forming a mixing chamber, and combustion air is supplied to the mixing chamber wall from the fuel nozzle. By providing a plurality of air introduction passages to be introduced into the mixing chamber together with the fuel supplied from the fuel, the mixture of fuel and air is promoted in the air introduction passage and in the mixing chamber, and NOx is reduced by premixed combustion. Is possible.
On the other hand, the ignition characteristics and flame propagation characteristics at the time of starting the gas turbine show better characteristics as the fuel concentration of the air-fuel mixture increases (that is, the fuel-air ratio is larger). Since the fuel concentration tends to be made uniform, the ignition characteristics and flame propagation characteristics at the time of starting the gas turbine may deteriorate.

  An object of the present invention is to reduce NOx by premixed combustion in a gas turbine combustor by promoting mixing of fuel and air in an air introduction passage provided in a mixing chamber wall of a burner and in a mixing chamber. The aim is to improve ignition characteristics and flame propagation characteristics.

  According to the first aspect of the present invention, there are provided a plurality of combustors for supplying a combustion gas generated by combustion of a mixture of fuel and combustion air introduced from a compressor to a gas turbine, and igniting the mixture. In a gas turbine combustor comprising an ignition plug and a flame propagation tube for propagating a flame caused by combustion of the air-fuel mixture between the combustors, the combustor is opened downstream in the axial direction of the combustor. A burner having a mixing chamber wall that forms a mixing chamber and a fuel nozzle that supplies fuel, and a plurality of combustion air is introduced into the mixing chamber together with fuel from the fuel nozzle in the mixing chamber wall. A gas turbine combustor in which combustion air and fuel jetted from the air introduction passage to the mixing chamber flow toward at least one of the spark plug and the flame propagation pipe. .

  According to this, in a gas turbine combustor comprising a plurality of combustors, spark plugs and flame propagation tubes, combustion air is introduced from an air introduction passage for introducing combustion air into a mixing chamber of a burner provided in each combustor. Becomes a gas mixture with the fuel supplied from the fuel nozzle and is jetted into the mixing chamber, and the jetted gas mixture flows toward at least one of the spark plug and the flame propagation tube. As a result, since an air-fuel mixture having a high fuel concentration exists at and near the installation position of at least one of the spark plug and the flame propagation tube, ignition is facilitated, and at least one of the ignition characteristic and the flame propagation characteristic is improved. The startability of the gas turbine is improved.

According to a second aspect of the present invention, in the gas turbine combustor according to the first aspect, a plurality of the air introduction passages are arranged in the first row and the second row in the axial direction or the radial direction in the mixing chamber wall. The air introduction passage through which combustion air that flows toward the spark plug is ejected belongs to the first row, and the air introduction passage from which combustion air that flows toward the flame propagation tube is ejected Belongs to the second column.
According to this, since the air introduction passages for injecting the air-fuel mixture directed to the spark plug and the flame propagation pipe are provided separately in the first and second rows, the arrangement and shape of the air introduction passages in the mixing chamber wall The degree of freedom becomes greater, and it becomes easier to design a suitable air introduction passage from the viewpoint of improving ignition characteristics and flame propagation characteristics.

  Invention of Claim 3 is provided with the center burner which is the said burner, and the some outer periphery burner arrange | positioned on the outer peripheral side with respect to the said center burner, The said center burner is a gas turbine combustor of Claim 1 A central mixing chamber wall that is the mixing chamber wall that forms the central mixing chamber that is the mixing chamber, and a central fuel nozzle that is the fuel nozzle, and the outer peripheral burner is directed downstream in the axial direction. An outer peripheral mixing chamber wall that forms an open outer peripheral mixing chamber; and an outer peripheral fuel nozzle that supplies fuel to the outer peripheral mixing chamber; and the central mixing chamber wall includes a plurality of the combustion air introduction passages, The air introduction passage, which is provided side by side in the first row and the second row in the axial direction and from which combustion air that flows toward at least one of the spark plug and the flame propagation tube is jetted, belongs to the first row. The first Combustion air ejected from the air induction passage belonging to the column are those flows directed to the outlet of the outer peripheral mixing chamber.

According to this, the combustion air spouted together with the fuel from the air introduction hole is spouted toward the outlet of the outer peripheral burner, whereby the air-fuel mixture spouted from the air introduction passage belonging to the second row at the outlet of the outer peripheral burner. Since high-temperature combustion gas is supplied by combustion, combustion of the air-fuel mixture supplied from the outer peripheral burner becomes easy. For example, even when the fuel concentration of the air-fuel mixture in the outer peripheral burner is low, combustion is easily started. be able to. As a result, the combustibility of the combustor including the outer peripheral burner is improved, and the operation load range of the gas turbine can be expanded.
Further, since the air introduction passages are provided in the first and second rows, the degree of freedom in the arrangement and shape of the air introduction passages on the mixing chamber wall is increased, and the ignition characteristics or flame propagation characteristics are improved. From the viewpoint of facilitating the start of combustion of the air-fuel mixture from the burner, it becomes easy to design a suitable air introduction passage.

According to a fourth aspect of the present invention, in the gas turbine combustor according to the third aspect, the number of the air introduction passages constituting the second row of the central burners is an integral multiple of the number of the outer peripheral burners. is there.
According to this, since the number of the air introduction passages is an integral multiple of the number of the outer peripheral burners, the air introduction passages for ejecting the air-fuel mixture flowing toward the outer peripheral burners can be equally assigned to each outer peripheral burner. In addition, since the arrangement and shape of the plurality of air introduction passages for this purpose can be easily made, the combustion stability can be improved while simplifying the structure of the burner.

According to a fifth aspect of the present invention, in the gas turbine combustor according to the third or fourth aspect, of the first row and the second row, the air introduction passage constituting the upstream row in the axial direction is The number of the air introduction passages constituting the downstream row is 12, and the number of the outer peripheral burners is 4 or 6.
According to this, since there are more air introduction passages in the downstream row than in the upstream row, the air-fuel mixture flowing toward the downstream can be more reliably directed. Further, since the number of the air introduction passages in the downstream row is an integral multiple of the number of the outer peripheral burners, the same effect as that of the invention of claim 4 can be obtained.

  According to the present invention, in the gas turbine combustor, the mixing of fuel and air is promoted in the air introduction passage and in the mixing chamber, so that NOx can be reduced by premixed combustion, and the ignition characteristics and flame can be reduced. Propagation characteristics can be improved.

It is a principal part schematic sectional drawing of the gas turbine plant in which the gas turbine provided with the gas turbine combustor which concerns on Example 1 of this invention was used. It is the schematic explaining the combustor and flame propagation pipe with which the gas turbine combustor of FIG. 1 is provided. It is a principal part enlarged view of FIG. 1, and the air introduction hole of a burner is shown simply. It is sectional drawing in the IV-IV line of FIG. It is sectional drawing in the VV line | wire of FIG. FIG. 5 is a diagram illustrating a modified example of Example 1 and corresponding to the main part of FIG. 3. FIG. 4 shows a second embodiment of the present invention and corresponds to FIG. 3. In Example 2, it is a figure equivalent to FIG. In Example 2, it is a graph which shows the relationship between the load of a gas turbine, and the fuel flow volume of a burner. FIG. 4 shows a third embodiment of the present invention and corresponds to FIG. 3. In Example 3, it is a figure equivalent to FIG. In Example 3, it is a graph equivalent to FIG. FIG. 4 shows a fourth embodiment of the present invention and corresponds to FIG. 3. In Example 4, it is a figure equivalent to FIG.

  Hereinafter, a gas turbine combustor according to an embodiment of the present invention will be described with reference to FIGS.

Example 1
A gas turbine combustor 4 according to Embodiment 1 of the present invention will be described with reference to FIGS.
Referring to FIG. 1, a gas turbine plant including a gas turbine 1 is a power generation gas turbine plant including a generator 2 as a driving target driven by the gas turbine 1.

The gas turbine 1 includes a compressor 3 that compresses air, a gas turbine combustor 4 that generates combustion gas by burning fuel with combustion air that is part of the compressed air obtained by the compressor 3, and a gas A turbine 5 driven and rotated by a high-temperature and high-pressure combustion gas generated in the turbine combustor 4, a transition piece 6 that guides the combustion gas from the gas turbine combustor 4 to the turbine 5, and gaseous fuel ( For example, a fuel supply system 7 that supplies fuel that is liquefied natural gas) and a casing 8 that forms a casing 9 through which compressed air discharged from the compressor 3 flows and supports the gas turbine combustor 4 are provided.
The compressor 3 and the generator 2 are connected to a turbine 5 and are rotationally driven by the turbine 5. A transition piece 6 is accommodated in the passenger compartment 9.

  Referring also to FIG. 2, the gas turbine combustor 4 includes a plurality of, in this case, 10 pieces, which are arranged at equal intervals in the circumferential direction around the rotation center line C <b> 1 of the turbine 5 and the compressor 3. The can-type combustor 10, a spark plug 13 that ignites an air-fuel mixture generated by mixing fuel and combustion air, a connection pipe 14 that connects the combustors 10, and a connection pipe 14. And a flame propagation tube 15 for propagating a flame caused by the combustion of the air-fuel mixture between the combustors 10.

  Among all the combustors 10 constituting the gas turbine combustor 4, some of the combustors 10 are the first combustion as one or a plurality of (here, two specific combustors) provided with the spark plugs 13. The remaining combustor 10 is a second combustor 12 that is not provided with a spark plug 13. The first combustor 11 and the second combustor 12 have basically the same structure except for the structure related to the spark plug 13 in the first combustor 11. In the following description, when the first and second combustors 11 and 12 are not distinguished from each other, they are simply referred to as the combustor 10.

Referring to FIGS. 1 and 3, each combustor 10 that supplies combustion gas generated by combustion of a mixture of fuel and combustion air to the gas turbine 1 is a cylindrical inner cylinder that forms a combustion chamber 20. 21, a cylindrical outer cylinder 22 that is disposed surrounding the inner cylinder 21 and forms an annular air passage 23 between which the combustion air from the compressor 3 flows, and an upstream end wall , An end cover 24 that is disposed on the combustor axis C <b> 2, and a burner 30 that supplies combustion air and fuel to the combustion chamber 20, and an outlet of the burner 30 that assists in holding the combustion flame. And a flame holding plate 25 as a flame holding member.
And the air compressed with the compressor 3 flows in into the compartment 9 from the compressor 3, The one part is supplied to the combustor 10 as combustion air.

The combustor axis C2 (see also FIG. 2) is the central axis of the inner cylinder 21 or the combustion chamber 20, and the axial direction is a direction parallel to the combustor axis C2, and unless otherwise specified, the radial direction and the circumferential direction. The directions are assumed to be a radial direction and a circumferential direction around the combustor axis C2, respectively.
Further, the upstream and the downstream are respectively related to the flow in the axial direction of the combustion air in the burner 30 or the combustion gas in the burner 30 and the combustion chamber 20.

  The burner 30 disposed so that its center is substantially located on the combustor axis C2 includes a mixing chamber wall 32 that forms a mixing chamber 31 that opens toward the combustion chamber 20 in the axial direction, and a fuel nozzle 38 that supplies fuel. And have. The mixing chamber wall 32 is disposed on the upstream side of the combustion chamber 20 in the axial direction, and has a hollow conical shape that expands in the radial direction toward the combustion chamber 20 in the axial direction with the combustor axis C2 as the central axis. In addition, a conical mixing chamber 31 that is widened toward the downstream side at the apex angle α is formed by the conical surface of the mixing chamber wall surface 33. Therefore, the mixing chamber wall surface 33 has a conical surface shape with an apex angle α.

  The mixing chamber wall 32 is provided with a plurality of air introduction holes 35, 36, and 37 that respectively form a plurality of air introduction passages for introducing combustion air into the mixing chamber 31. Air introduction holes 35, 36, and 37 that are linear circular holes form different angles β 1, β 2, and β 3 with respect to the mixing chamber wall surface 33, respectively. The angles β1, β2, and β3 are intersections of the center line of the air introduction holes 35, 36, and 37 and the generatrix of the conical mixing chamber wall surface 33 (mixing chamber wall surface 33 and the plane including the combustor axis C2). Is the angle between

  The fuel supply system 7 includes a fuel supply device 41, a fuel distributor 42, and a fuel supply pipe 43. The fuel nozzle 38 is connected to a fuel supply pipe 43 for guiding the fuel from the fuel supply device 41 via the fuel distributor 42 that distributes the fuel to each combustor 10. Then, the fuel from the fuel supply pipe 43 is supplied to the fuel nozzle 38 having the fuel manifold portion 38a, and the fuel ejected from the fuel nozzle 38 is supplied into each of all the air introduction holes 35, 36, and 37. Are arranged as follows. Accordingly, each air introduction hole 35, 36, 37 introduces combustion air into the mixing chamber 31 while generating an air-fuel mixture with the fuel supplied from the fuel nozzle 38.

In each of the two combustors 11, the spark plug 13 is attached to the outer cylinder 22 so that the ignition part 13 a is located in the combustion chamber 20.
Further, the combustors 10 adjacent to each other in the circumferential direction are connected by a connecting pipe 14 that connects the outer cylinders 22 to each other. The combustion chambers 20 or the inner cylinders 21 of the combustor 10 communicate with each other through a flame propagation tube 15. Openings at both ends of the flame propagation tube 15 constitute an entrance / exit 15 a that is open to the combustion chamber 20. Here, it is meant that each inlet / outlet 15 a can be a flame inlet to the adjacent combustor 10 and a flame outlet from the adjacent combustor 10.

  And the pressure in the combustion chamber 20 which is the inside of the inner cylinder 21 rises by the combustion gas produced by combustion of the air-fuel mixture ignited by the ignition plug 13 in the combustor 11 including the ignition plug 13, A pressure difference is generated between the combustion chambers 20 of the adjacent combustors 12 communicated by the flame propagation pipe 15, and the combustion gas 27 sent to the adjacent combustors 12 due to the pressure difference is generated in the adjacent combustors 12. Ignite the air-fuel mixture. Similarly, the adjacent combustors 12 are sequentially ignited by the flame propagation tube 15, and all the combustors 10 are ignited.

Referring to FIGS. 3 and 4, the air introduction holes 35 to 37 formed in the mixing chamber wall 32 are arranged in a plurality of rows in the axial direction in the first embodiment in the first to third rows R1 to R3. They are arranged in three rows. Each of these rows R1 to R3 has one or more, here a plurality of air introduction holes 35 to 37, arranged annularly at intervals in the circumferential direction on the circumference at the formation position in the axial direction. Consists of.
In addition, in order to avoid the complexity of a figure, in FIG. 4, a part of structure shown in FIG. 3 is abbreviate | omitted.

  In the mixing chamber wall 32, as partially shown in FIGS. 4 and 5, a plurality of air introduction holes 35 to 37 belonging to the respective rows R1 to R3 are concentrically centered on the combustor axis C2. Has been placed. Further, the air introduction hole 37 is formed by being deflected in the circumferential direction so that a swirling flow is generated in the mixing chamber 31 by the combustion air ejected from the air introduction holes 35 to 37, and the air introduction holes 35 and 36 are formed. Is formed by being deflected in the axial direction and the circumferential direction.

  Further, regarding the positions of the first row R1 and the second row R2 in the axial direction, the first row R1 is the upstream row located on the upstream side of the first and second rows R1, R2, and the second row Row R2 is a downstream row located on the downstream side. Further, the second row R2 is located on the outer side in the radial direction than the first row R1, and is disposed on a circumference having a larger diameter than the first row R1.

  Referring to FIG. 4, in each combustor 10, one or more of the air introduction holes 35 to 37, in this embodiment, a plurality of specific air introduction holes 35 a and 35 b serving as specific air introduction passages to the mixing chamber 31. The combustion air spouted into the inside of the specific air introduction holes 35a and 35b together with the fuel flowing together with the combustion air together with the ignition portion 13a of the ignition plug 13 and the inlet / outlet port 15a of the flame propagation tube 15 installed in the inner cylinder 21 The specific air introduction holes 35a and 35b are formed so as to be deflected in the axial direction and the circumferential direction.

Specifically, in the combustor 11, the combustion air and fuel mixture m1 ejected from the first specific air introduction hole 35a flows toward the ignition unit 13a, and the two second specific air introduction holes 35b. Combustion air and fuel mixture m2 ejected from the air flow toward the inlet / outlet port 15a of the two flame propagation tubes 15.
Further, in the combustor 12 (see FIG. 1), the mixture of combustion air and fuel ejected from the second specific air introduction hole 35b flows toward the inlet / outlet port 15a of the two flame propagation tubes 15.

Referring to FIG. 5, since the air introduction hole 37 is formed at a position offset from the combustor axis C <b> 2, which is also the burner center line of the burner 30, by the offset distance s, the air-fuel mixture flowing from the air introduction hole 37 is mixed. A swirling flow is generated in the chamber 31. Similarly to the air introduction hole 37, the air introduction holes 35 and 36 are formed at positions offset from the burner center line by an offset distance s, so that a swirl flow can be generated in the mixing chamber 31. It becomes. Then, a stable circulating flow is generated in the downstream portion of the burner 30 by the swirling flow, and combustion stability can be ensured.
In the present embodiment, the air-fuel mixture m1, m2 ejected from the specific air introduction holes 35a, 35b of the air introduction holes 35 belonging to the first row R1 flows in a direction toward the spark plug 13 or the flame propagation pipe 15. In order to form the introduction hole 35, the apex angle α of the mixing chamber wall 32 forming the mixing chamber 31, the formation angle β2 of the air introduction hole 35, and the offset distance from the burner center line (or combustor axis C2). The flow direction of the air-fuel mixture is determined by s.

  In this embodiment, the ratio s / d of the offset distance s from the burner center line with respect to the inner diameter d (see FIG. 5) of the mixing chamber 31 that forms the air introduction holes 35 to 37 is arbitrarily set. The mixture m1 and m2 (see FIG. 4) of fuel and combustion air ejected from the air introduction hole 35 is deflected to the installation position of the spark plug 13 and the flame propagation pipe 15, and the ratio s of the air introduction holes 35 to 37 is determined. By controlling / d, it becomes possible to generate a circulating flow necessary for combustion stability in the downstream portion of the burner 30, so that the gas turbine combustor 4 that excels in ignition characteristics and flame propagation characteristics and stably burns is provided. It becomes possible to provide.

  3 and 4, in the gas turbine combustor 4 configured as described above, when the gas turbine 1 is started and when the gas turbine combustor 4 is ignited, the fuel supply device 41 (see also FIG. 1) is used. Fuel is supplied to the fuel nozzle 38. The fuel is ejected from the fuel nozzle 38 toward the air introduction holes 35 to 37 and is mixed with combustion air in the air introduction holes 35 to 37 and in the mixing chamber 31 to generate an air-fuel mixture. Then, the air-fuel mixture ejected from the air introduction holes 35 to 37 is ignited by the spark of the spark plug 13 and premixed combustion is performed.

At that time, the first row R1 of the first to third rows R1 to R3, that is, the specific air introduction holes 35a of the air introduction holes 35 constituting the second from the upstream side (second from the left in FIG. 3), The specific air introduction holes 35a and 35b are formed so that the air-fuel mixture m1 and m2 are jetted toward the ignition portion 13a of the spark plug 13 and the inlet / outlet port 15a of the flame propagation pipe 15 from 35b.
For this reason, in the combustor 11, since there is an air-fuel mixture having a high fuel concentration (that is, a large fuel-air ratio) in the vicinity of the ignition portion 13 a of the spark plug 13, ignition is facilitated and ignition characteristics are improved. To do.

Further, when the combustor 11 is ignited, the pressure of the combustion chamber 20 is increased, so that the combustion gas 27 is ejected to the adjacent unignited combustor 11 through the flame propagation tube 15. Since the air-fuel mixture m2 is ejected from the air introduction holes 35a and 35b toward the inlet / outlet 15a of the flame propagation pipe 15, the inlet / outlet 15a (in this case, functions as an outlet) in the combustor 11 and the vicinity thereof. Can produce a combustion gas having a high temperature because an air-fuel mixture with a high fuel concentration exists. For this reason, this high-temperature combustion gas (flame) is ejected through the flame propagation pipe 15 into the combustion chamber 20 of the adjacent combustor 12.
On the other hand, in the adjacent combustor 12 through which the flame from the combustor 11 propagates, the air-fuel mixture having a high fuel concentration from the specific air introduction hole 35b functions as an inlet / outlet 15a of the flame propagation pipe 15 (in this case, functions as an inlet). Therefore, the combustion gas that has flowed in from the combustor 11 through the flame propagation tube 15 facilitates flame propagation and facilitates the start of combustion, thereby improving the flame propagation characteristics.

In the first embodiment, the mixing chamber wall 32 is formed with the apex angle α, the conical mixing chamber 31 is formed, and the fuel jetted from the fuel nozzle 38 and the combustion air jetted from the air introduction holes 35 to 37 are formed. Since the fuel and fuel are mixed in the mixing chamber 31, the effect of further reducing NOx emissions due to the premixed combustion in the air-fuel mixture with improved homogenization and the swirling flow of the air-fuel mixture in the mixing chamber 31 are mixed. By being restrained by the chamber wall 32, it is possible to expect an effect of increasing the swirl strength and improving the combustion stability.
Furthermore, since the mixing chamber wall 32 has a hollow conical shape, the formation region of the air introduction holes 35 to 37 in the mixing chamber wall 32 is increased as compared with the case where the mixing chamber wall 32 is an annular flat plate, for example. There is an advantage that the degree of freedom in determining the air introduction hole specifications such as the number of the air introduction holes 35 to 37 and the diameter of the air introduction holes 35 to 37 is increased, and the formation of the air introduction holes 35 to 37 is facilitated. .

The axial direction position of the spark plug 13 or the flame propagation tube 15 in the inner cylinder 21 is set such that the inner diameter of the inner cylinder 21 is D, and the distance from the upstream end of the inner cylinder 21 to the ignition part 13a or the entrance / exit 15a is L. In this case, the ratio L / D is often in the range of 0.3 <L / D <0.7. Therefore, the specific air introduction holes 35a and 35b are formed so that the air-fuel mixture ejected from the specific air introduction holes 35a and 35b is directed to a position where 0.3 <L / D <0.7 in the inner cylinder 21. Is desirable.
Further, since the ignition plug 13 can improve the ignition characteristics by adjusting the radial position inserted into the inner cylinder 21, if the axial position of the ignition plug 13 and the flame propagation pipe 15 are significantly different, the flame propagation pipe It is desirable to form the specific air introduction hole 35b so that the air-fuel mixture m2 is ejected toward the position where the 15 entrances 15a are formed.

When the air introduction holes 35 to 37 are formed so as to be arranged in a plurality of rows in the axial direction, as a modified example of the first embodiment, mixing from the air introduction holes 35 belonging to the first row R1 which is one row is performed. The air introduction hole 35 is formed to be deflected so that the air m1 is directed to the ignition part 13a of the spark plug 13, and is mixed from the air introduction hole 36 in the second row R2, which is a row different from the first row R1. The air introduction hole 36 is formed to be deflected so that the gas m2 is ejected toward the inlet / outlet port 15a of the flame propagation tube 15, and the third row R3 (which may be one or more rows) is the remaining row. .), The air-introducing holes 37 are formed so that the air-fuel mixture from the air-introducing holes 37 in the third row R3 generates a swirling flow in the mixing chamber 31 and contributes to combustion stability. May be.
As a result, like the first embodiment, the ignition characteristics and flame propagation characteristics are improved, and it is possible to provide the burner 30 with improved startability of the gas turbine 1 and excellent combustion stability.
Further, since the specific air introduction holes 35a and 35b for ejecting the air-fuel mixture m1 and m2 directed to the ignition part 13a and the inlet / outlet port 15a are provided respectively in the first and second rows R1 and R2, the mixing chamber wall 32 is provided. The degree of freedom in the arrangement and shape of the air introduction passages 35 and 36 in the air increases, making it easy to design the air introduction holes 35 and 36 suitable from the viewpoint of improving the ignition characteristics and flame propagation characteristics.

In the gas turbine combustor 4 according to the first embodiment, liquid fuel (for example, A heavy oil or light oil) may be used as the fuel for the gas turbine 1 in addition to the gaseous fuel. This another modified example of the first embodiment will be described mainly with reference to FIG. 6 with reference to FIGS.
The combustor 10 is disposed on the upstream side of the mixing chamber 31 of the burner 30 including the fuel nozzle 38 as the first fuel nozzle for supplying the gaseous fuel as the first fuel, and injects the liquid fuel as the second fuel. The liquid fuel nozzle 39 is provided as a second fuel nozzle. Liquid fuel is supplied to the liquid fuel nozzle 39 from a fuel supply device 44 provided in the fuel supply system 7.

  The liquid fuel nozzle 39 sprays the liquid fuel, mixes it with the high-temperature combustion air 5 in the mixing chamber 31 and evaporates it to burn, and plays a role of atomizing the liquid fuel into small droplets. To atomize liquid fuel, there are an air spray type fuel nozzle that atomizes using the shear force of air and a pressure spray type fuel nozzle that atomizes using the supply pressure of liquid fuel. For example, the effect of the present invention can be applied even if a liquid fuel nozzle by any method or a spray method other than those described above is applied.

In this embodiment, since the liquid fuel nozzle 39 is installed on the combustor axis C2 of the burner 30 and on the upstream side of the mixing chamber 31, the droplet sprayed conically from the liquid fuel nozzle 39 is burner 30. In the mixing chamber 31, the air is mixed with the combustion air ejected from the air introduction holes 35 to 37.
As in the first embodiment, the combustion air from the air introduction hole 35 is blown out toward the ignition part 13a of the ignition plug 13 installed in the inner cylinder 21 and the inlet / outlet port 15a of the flame propagation pipe 15. 35 is formed by being deflected in the axial direction and the circumferential direction. Therefore, the air-fuel mixture from the air introduction hole 35 and the atomized liquid fuel from the liquid fuel nozzle 39 are located at the installation positions of the ignition part 13a and the entrance / exit 15a. Since the air-fuel mixture is supplied, the ignition characteristics and flame propagation characteristics can be improved by the air-fuel mixture having a high fuel concentration.

  The spray angle of the liquid fuel nozzle 39 disposed in the burner 30 (the spread angle at which the liquid fuel sprays) is set smaller than the apex angle α of the mixing chamber 31. When the spray angle of the liquid fuel nozzle 39 becomes larger than the apex angle α, droplets sprayed from the liquid fuel nozzle 39 collide with the mixing chamber wall 32, and coking occurs in which the liquid fuel is carbonized in the mixing chamber wall 32, There is a possibility that various performances of the burner 30 may be deteriorated. For this reason, when the spray angle of the liquid fuel nozzle 39 is smaller than the apex angle α, the occurrence of coking can be prevented.

(Example 2)
A second embodiment of the present invention will be described below with reference to FIGS. In the second embodiment, a plurality of main burners 50, 60 are arranged on the outer peripheral side of the burner 30, and the rest has basically the same configuration as the first embodiment.

In the second embodiment and later-described third and fourth embodiments, the description of the same parts as those in the first embodiment will be omitted or simplified, and different points will be mainly described. Moreover, the same code | symbol is used as needed about the member same as the member of Example 1, or a corresponding member. And Example 2-4 has the same effect as Example 1. FIG.
Further, in Examples 2 to 4, the mixing chamber wall, the mixing chamber 31 and the fuel nozzle are the central mixing wall, the central mixing chamber and the central fuel nozzle, respectively, and the mixing chamber wall, the mixing chamber and the fuel nozzle are respectively mixed at the outer periphery. A wall, a peripheral mixing chamber and a peripheral fuel nozzle. Further, the burner and the pilot burner are a central burner, and the main burner is an outer peripheral burner.
Furthermore, in the diagrams relating to the second to fourth embodiments, only the air-fuel mixtures m3 and m4 which are directed to some main burners, for example, are illustrated in order to avoid the complexity of the diagram.

7 and 8, the burners 30, 50, 60 of the combustor 10 included in the gas turbine combustor 4 according to the second embodiment are composed of a burner 30 as a pilot burner and main burners 50, 60. The
One or more, here six, main burners 50 and 60 arranged on the outer peripheral side (that is, radially outward) with respect to the burner 30 are the same number of three first burners. The main burner 50 and the second main burner 60 are configured.

  Each of the main burners 50, 60 includes mixing chamber walls 52, 62 as outer mixing walls forming outer mixing chambers 51, 61 as outer mixing chambers that open toward the downstream in the axial direction, and outer peripheral fuel nozzles for supplying fuel. And fuel nozzles 59 and 69. Mixing chamber walls 52 and 62 disposed on the upstream side of the combustion chamber 20 in the axial direction are conical mixture chamber wall surfaces 53 that expand toward the combustion chamber 20 in the axial direction around the combustor axis C2. 63, and upstream downstream wall portions 52a and 62a, and cylindrical downstream wall portions 52b and 62b that extend downstream from the upstream wall portions 52a and 62a. Form. The mixing chamber walls 52 and 62 have a cylindrical outer peripheral surface.

The main burners 50 and 60 have basically the same structure as the burner 30, but the mixing chambers 51 and 61 are arranged in the axial direction in order to promote mixing of combustion air and fuel in the mixing chambers 51 and 61. Is longer than the mixing chamber 31 of the burner 30.
A plurality of air introduction holes 55 to 57 and 65 to 67 for introducing combustion air or combustion air together with fuel are formed in the mixing chambers 51 and 61 in the upstream walls 52a and 62a. The air introduction holes 55 to 57 and 65 to 67 are arranged so as to be arranged in three rows as a plurality of rows in the axial direction. Further, the second row R2 is closer to the outlet of the burner 30 and the outlets of the main burners 50 and 60 than the first row R1 in the axial direction.

The fuel nozzles 59, 69 are fuel manifolds 59 a, 69 a formed in the upstream part of the main burners 50, 60, and fuel jets that connect the fuel manifolds 59 a, 69 a and the air introduction holes 55-57, 65-67. It consists of holes 59b and 69b.
The fuel supplied from the fuel supply devices 45 and 46 included in the fuel supply system 7 to the fuel manifolds 59a and 69a is jetted and supplied from the fuel injection holes 59b and 69b into the air introduction holes 55 to 57 and 65 to 67. The
The fuel supplied to the air introduction holes 55 to 57 and 65 to 67 is mixed with the combustion air inside the air introduction holes 55 to 57 and 65 to 67 and inside the mixing chambers 51 and 61, and the main burners 50 and 60 are mixed. A premixed flame is formed in the combustion chamber 20 on the downstream side, and premixed combustion is started.

  As described above, the main burner 50 has the same structure as that of the main burner 60, while fuel is supplied from a fuel supply device 45 different from the fuel supply device 46 of the main burner 60. Therefore, fuel is supplied separately from the fuel supply device 20 to the burner 30, from the fuel supply device 45 to the three main burners 50, and from the fuel supply device 46 to the other three main burners 60.

Next, with reference to FIG. 9, the operating method of the gas turbine 1 (refer FIG. 1) provided with the gas turbine combustor 4 which concerns on Example 2 is demonstrated.
When the load as an indicator of the operation state of the gas turbine 1 is a load state from the load a (no load) to less than the load b, fuel is supplied to the burner 30 and the gas turbine 1 is operated by the burner 30 alone. The In the load state from the load b to less than the load c, the fuel flow rate of the burner 30 is decreased by the load b, while the fuel is supplied to the main burner 50 and the gas turbine 1 is operated by the burner 30 and the main burner 50. The In the load state from the load c to the rated load d, the fuel flow rate of the burner 30 and the main burner 50 is reduced by the load c, while the fuel is supplied to the main burner 60 and the burner 30 and the main burners 50, 60 are all The gas turbine 1 is operated by the burner.

At the rated load d, which is a load in the rated operating state, low NOx combustion is performed by adjusting the ratio of the fuel flow rate of the burner 30 and the fuel flow rate of the main burners 50 and 60 while ensuring combustion stability. Is possible.
As described above, in the second embodiment, the burner 30 is disposed at the center on the combustor axis C2 of the combustor 10, and the six main burners 50 and 60 are disposed on the outer peripheral side thereof. It is possible to achieve both low NOx operation and combustion stability by adjusting the fuel flow rate ratio between the burner 30 that burns and the main burners 50 and 60 that premix and burn.

  By the way, as shown in FIGS. 7 and 8, in a combustor in which main burners 50 and 60 are disposed on the outer peripheral side of the burner 30, and the spark plug 13 and the flame propagation pipe 15 are disposed on the outer periphery, combustion is performed. It is conceivable that the ignition characteristics and flame propagation characteristics of the burner 30 are deteriorated by the combustion air ejected from the main burners 50 and 60 at the time of ignition of the burner.

  Further, in the combustor 10 of the second embodiment, as shown in FIG. 9, the fuel is supplied to the main burner 50 with the load b from the burner 30 independent operation state as the pilot burner, and the preburn combustion is performed in the main burner 50. The fuel is supplied to the main burner 60 with the load c, and the operation with all the burners is started. For this reason, when the premixed combustion is started or stopped by the main burners 50, 60, the combustion may become unstable depending on the load state. It is desirable to be in an operating state at a high load equal to or higher than the load c in which fuel is supplied to the burners 30, 50, 60. On the other hand, since the load range of the gas turbine 1 that can be operated is expanded by setting the load c, which is the operation state in which the fuel supply to all the burners 30, 50, 60 is started, to be low, the degree of freedom of operation increases. To do.

  Therefore, in the second embodiment, the air introduction holes 36 belonging to the second row R2 are formed such that the air-fuel mixtures m3 and m4 from the air introduction holes 36 are ejected toward the outlets of the main burners 50 and 60, respectively. Therefore, high-temperature combustion gas is supplied to the outlets of the main burners 50 and 60. For this reason, premixed combustion can be started by the main burners 50 and 60 even under conditions where the fuel concentration of the air-fuel mixture supplied from the main burners 50 and 60 is low, that is, in an operating state where the load of the gas turbine 1 is low. Thus, it is possible to set the load c, which is the starting load of combustion in all the burners 30, 50, 60, to a low load, and it is possible to widen the operating load zone of the gas turbine 1.

As shown in FIG. 8, as in the first embodiment, in the combustor 11, the air / fuel mixture m <b> 1 from the specific air introduction hole 35 a is ejected toward the ignition portion 13 a of the spark plug 13 and the specific air is introduced. Since the air-fuel mixture m2 from the hole 35b is ejected toward the inlet / outlet port 15a of the flame propagation tube 15, the fuel-rich air mixture m1 and m2 can be supplied to the installation positions of the spark plug 13 and the flame propagation tube 15, Ignition characteristics and flame propagation characteristics at the start of the gas turbine 1 are improved.
Further, since the spark plug 13 and the flame propagation pipe 15 are arranged in the middle of the main burners 50 and 60 in the circumferential direction, the air-fuel mixture m1 and m2 are combustion air or air-fuel mixture ejected from the main burners 50 and 60. In this respect, the ignition characteristics and flame propagation characteristics are improved.

  Further, as shown in the figure, six air introduction holes 35 and twelve air introduction holes 36 are formed in the burner 30, and six main burners 50 and 60 are arranged on the outer peripheral side of the burner 30. The number of air introduction holes 36 formed in the first burner 30 is set to an integral multiple of the number of main burners 50 and 60, and the position of the air introduction holes 35 in the first row R1 in the circumferential direction is set to set the burner 30. Can be efficiently used for improving the ignition characteristics and flame propagation characteristics at the start of the gas turbine 1, and further, by setting the arrangement of the air introduction holes 36 in the second row R2 in the circumferential direction, Since the heat energy of the combustion gas of the burner 30 can be efficiently transmitted to the main burners 50 and 60 that perform premix combustion, the operation of all the burners can be performed from when the load of the gas turbine 1 is low. But, it is possible to enlarge the load range that can be operating a gas turbine 1 stably.

  Further, specific air introduction holes 35a and 35b for injecting the air-fuel mixtures m1 and m2 directed to the ignition part 13a and the inlet / outlet 15a, and the air introduction holes 36 for injecting the air-fuel mixture m3 and m4 directed to the outlets of the main burners 50 and 60, respectively. Are arranged in the first and second rows R1 and R2, respectively, so that the degree of freedom in the arrangement and shape of the air introduction holes 35 and 36 in the mixing chamber wall 32 is increased, and the ignition characteristics and flame propagation characteristics are increased. From the viewpoint of improvement, it is easy to design the air introduction holes 35 and 36 suitable.

  In addition, since the number of the air introduction holes 36 is an integral multiple of the number of the main burners 50 and 60, the air introduction holes 36 for ejecting the air-fuel mixture flowing toward the main burners 50 and 60 are provided in the main burners 50 and 60. It is possible to evenly assign every 60, and the arrangement and shape of the plurality of air introduction holes 36 for that purpose can be easily equalized, so that the combustion stability can be improved while simplifying the structure of the burner 30. . Further, since the second row R2 located downstream of the first row R1 has more air introduction holes than the first row R1, the air-fuel mixture flowing toward the downstream side is more reliably supplied to the main burners 50, 60. Can be oriented.

(Example 3)
A third embodiment of the present invention will be described below with reference to FIGS.
Referring to FIGS. 10 and 11, the burners 70 and 80 of the combustor 10 included in the gas turbine combustor 4 according to the third embodiment include a pilot burner 70 corresponding to the burner 30 of the second embodiment and a main burner 80. Composed.
The pilot burner 70 has a mixing chamber wall 72 that forms a conical mixing chamber 71 that opens toward the downstream in the axial direction, and a fuel nozzle 79 as a central nozzle that supplies fuel. The mixing chamber wall 73 of the mixing chamber wall 72 is formed in a conical surface shape, and a conical mixing chamber 71 is formed.
The mixing chamber wall 72 has a plurality of air introduction holes 75 and 76 that form a plurality of air introduction passages for introducing combustion air or combustion air into the mixing chamber 71 together with fuel in the axial direction. The fuel nozzles 79 are arranged so as to be arranged in two rows of R1 and R2, and on the upstream side thereof, a fuel nozzle 79 that jets and supplies fuel into the air introduction holes 75 and 76 is arranged.

The first row R1 is composed of six air introduction holes 75 that are one or more in number, here are plural, and are formed at intervals in the circumferential direction, and the second row R2 is one in number. It is comprised of 12 or more, here, a plurality of 12 air introduction holes 76 formed at intervals in the circumferential direction.
The air introduction holes 75 and 76 include straight portions 75c and 76c and deflection portions 75d and 76d that are connected to the straight portions 75c and 76c on the downstream side. The deflecting portions 75d and 76d, which are the outlet portions of the air introduction holes 75 and 76, are axially arranged so that a swirling flow is generated in the mixing chamber 71 by the combustion air or mixture injected from the air introduction holes 75 and 76. And it is formed by deflecting in the circumferential direction. The straight portions 75c and 76c including the inlet portions of the air introduction holes 75 and 76 extend substantially parallel to the axial direction from the deflecting portions 75d and 76d toward the upstream, and the length in the axial direction is the same as that in the axial direction. It is formed to be twice or more longer than the length of the deflecting portions 75d and 76d.
Further, the fuel from the fuel supply device 41 is supplied to the fuel nozzle 79 having the fuel manifold portion 79 a, and the fuel from the fuel nozzle 79 is ejected so as to be supplied into each air introduction hole 75.

The main burner 80 disposed on the outer peripheral side with respect to the pilot burner 70 includes a cylindrical mixing chamber wall 82 that forms a mixing chamber 81 that is opened downstream in the axial direction, and a fuel nozzle 89 that supplies fuel. Have. The mixing chamber wall 82 as the outer peripheral mixing chamber wall is composed of an outer peripheral chamber wall 82a and an inner peripheral chamber wall 82b.
The mixing chamber 81 whose axial length is longer than the axial length of the mixing chamber 71 extends in the axial direction and has an annular shape, and a fuel nozzle 89 is installed upstream of the mixing chamber 81 and mixed. An annular flame holder 84 is installed at the outlet of the chamber 81.

  Fuel from a fuel supply device 47 provided in the fuel supply system 7 is supplied to a fuel nozzle 89 having a fuel manifold portion 88. The fuel ejected from the fuel nozzle 89 is mixed with combustion air in the mixing chamber 81 to generate an air-fuel mixture. The air-fuel mixture flows downstream toward the combustion chamber 20, and premixed combustion is stably performed by the action of a circulating flow formed downstream of the flame holder 84. Further, a pilot burner cone 78 is installed between the pilot burner 70 and the main burner 80 in the radial direction.

Referring to FIG. 11, the mixing chamber 81 of the main burner 80 is divided into four mixing chambers 81 a to 81 d which are divided mixing chambers by four partition walls 87 as four partition members installed in the mixing chamber 71. It is divided into. In correspondence with the four mixing chambers 81a to 81d, the fuel supply device 47 is also divided into four fuel supply devices 47a to 47d, which are the same number of divided fuel supply devices as the mixing chambers 81a to 81d. Similarly, the fuel nozzle 89 is also divided into fuel nozzles 89a to 89d, which are four divided fuel nozzles, so that the fuel from each of the fuel supply devices 47a to 47d is individually supplied.
For this reason, the main burner 80 includes four divided main burners each including a mixing chamber wall constituted by each portion of the mixing chamber wall 82 and the partition wall 87 forming the mixing chambers 81a to 81d, and fuel nozzles 89a to 89d. The main burners 80a to 80d. The fuel supplied to the four fuel nozzles 89a to 89d can be individually controlled.

  As described above, the combustor 10 according to the third embodiment is an ultra-low NOx type in which the mixing chamber 81 is longer in the axial direction than the mixing chamber 71 of the pilot burner 70, thereby promoting the mixing of fuel and combustion air. Embodiments 1 and 2 in which the main burner 80 constituting the burner and the lengths of the air introduction holes 75 and 76 in the axial direction are linear portions 75c and 76c, so that only the portions corresponding to the deflection portions 75d and 76d are provided. The pilot burner 70 is longer than the air introduction holes 35 and 36.

  In the pilot burner 70, the mixing chamber wall surface 73 has a conical surface shape, and the upstream end wall surface 74 has a planar shape, so that the straight portions 75c and 76c extend parallel to the axial direction in the air introduction holes 75 and 76. Since it can be formed into a shape, mixing of combustion air and fuel is sufficiently promoted in the air introduction holes 75 and 76, and NOx emission from the flame formed by the pilot burner 70 can be reduced. It becomes.

  In the third embodiment, the number of the air introduction holes 75 on the inner peripheral side (or upstream side) of the pilot burner 70 is six in the circumferential direction, and the air introduction holes 76 on the outer peripheral side (or downstream side). It is formed with 12 pieces in the circumferential direction. For this reason, since the length of the air introduction hole 76 that is radially outward with respect to the air introduction hole 75 is longer than the length of the air introduction hole 75, the combustion air in the large number of air introduction holes 76. The fuel mixing distance becomes longer, and the mixing is promoted, which is advantageous for reducing NOx.

Further, since the deflecting portions 75d and 76d of the air introduction holes 75 and 76 are deflected in the axial direction and the circumferential direction, the effects related to this are the same as those in the first and second embodiments.
Specifically, according to the third embodiment, the fuel ejected from the fuel nozzle 79 is mixed with the combustion air in the air introduction holes 75 and 76 and ejected into the mixing chamber 71. Since the air introduction holes 75 and 76 are deflected in the axial direction and the circumferential direction, a swirling flow is generated in the mixing chamber 71. In addition, by adjusting the deflection angle of the air introduction holes 75 and 76, it is possible to control the ejection direction of the air-fuel mixture ejected from the air introduction holes 75 and 76.
Then, as shown in FIG. 11, the air-fuel mixture m <b> 1 and m <b> 2 is ejected from the specific air introduction holes 75 a and 75 b of the air introduction hole 75 toward the ignition part 13 a of the spark plug 13 and the inlet / outlet port 15 a of the flame propagation pipe 15. Therefore, a fuel-rich mixture is formed in the ignition portion 13a and the inlet / outlet port 15a and in the vicinity thereof, and the ignition characteristics and flame propagation characteristics are improved when the gas turbine 1 (see FIG. 1) is started.

  Further, the air-fuel mixture m3 ejected from the air introduction hole 76 is ejected to the downstream portion of the flame holder 84 (see FIG. 10) of the main burners 80a to 80d of the main burner 80, thereby premixed combustion in the main burner 80. Since the high-temperature combustion gas is supplied to the downstream portion of the flame stabilizer 84 when starting the premix combustion, it is possible to start the premix combustion under a low fuel concentration condition, and the main burner 80 starts the premix combustion. Combustion characteristics (hereinafter referred to as “switching characteristics”) are improved.

Next, the operation method of the gas turbine combustor 4 of the third embodiment will be described below with reference mainly to FIG. 12 while referring to FIG. 10 and FIG.
After starting the gas turbine 1 (see FIG. 1), the gas turbine 1 reaches the load e shown in FIG. 12 in the no-load rated rotational speed state, and the fuel is supplied only to the pilot burner 70. The load increases.
When the load of the gas turbine 1 reaches the load f, the fuel flow rate to the pilot burner 70 is reduced, fuel is supplied to the main burner 80a, and in the flame holder 84, downstream of the portion corresponding to the mixing chamber 81a. A premixed flame is formed. At this time, the fuel flow rates of the pilot burner 70 and the main burner 80a are substantially equal, and the air-fuel mixture ejected from the mixing chamber 71 obtains high thermal energy of the high-temperature combustion gas from the pilot burner 70 on the downstream side of the flame holder 84. Therefore, the switching characteristics of the premixed flame formed downstream of the mixing chamber 81a are good.

When the load of the gas turbine 1 rises and reaches the load g, the fuel is also supplied to the main burner 80b, and the fuel is also supplied to the main burner 80b at the load h to start premixed combustion. Since the ratio of the fuel flow rate of the pilot burner 70 to the fuel flow rate decreases, the switching margin tends to decrease (or decrease).
Here, the switching margin is an index of the breadth of the allowable range of the fuel-air ratio for ensuring combustion stability at the time of switching, and the higher (or larger) the switching margin is, the higher the fuel-air ratio is. Switching can be performed while ensuring the required combustion stability over a wide range, and switching characteristics are improved.

The load i is a load at which the entire pilot burner 70 and the main burner 80 (and therefore the main burners 80a to 80d) start combustion, and the ratio of the fuel flow rate of the pilot burner 70 to the fuel flow rate of the main burner 80 decreases. For this reason, the heat energy supplied from the pilot burner 70 is reduced, and the switching tolerance in the switching characteristics is reduced.
However, in the third embodiment, the air-fuel mixture m5 is ejected from the air introduction holes 75 in the first row R1 to the downstream side of the respective mixing chambers 81a to 81d, and further from the air introduction holes 76 in the second row R2. Since the gas m3 is ejected downstream of the mixing chambers 81a to 81d, it is possible to concentrate the high-temperature combustion gas downstream of the flame holder 84 at positions corresponding to the mixing chambers 81a to 81d. It becomes possible to improve the switching characteristic in i.

  In the third embodiment in which the mixing chamber 81 of the main burner 80 is divided into four mixing chambers 81a to 81d, the number of the air introduction holes 76 of the pilot burner 70 is set to 12, and the air introduction holes By making the number of 76 an integral multiple of the number of the mixing chambers 81a to 81d, it becomes possible to supply the thermal energy of the combustion gas by the pilot burner 70 evenly downstream of the mixing chambers 81a to 81d.

  Further, by setting the number of the air introduction holes 75 belonging to the first row R1 on the inner peripheral side of the pilot burner 70 to be 6, the fuel concentration in the ignition portion 13a of the spark plug 13 and the inlet / outlet port 15a of the flame propagation tube 15 and its vicinity. The air-fuel mixture m5 and m3 ejected from the air introduction holes 75 and 76 are ejected to the outlet of the mixing chamber 81d and the vicinity thereof at the load i at which the switching margin is most reduced while forming the rich air-fuel mixture. Compared to the mixing chambers 81b and 81c, the amount of air-fuel mixture supplied from the air introduction hole 75 on the inner peripheral side is doubled, so that the thermal energy of the combustion gas can be used effectively and the switching characteristics can be improved.

  Also, as shown in FIG. 12, at the load i, the switching characteristic is controlled to be improved by increasing the fuel flow rate of the pilot burner 70. However, if the thermal energy from the pilot burner 70 is too large, The temperature of the premixed flame rises and the amount of thermal NOx discharged increases. Therefore, after switching to full burner combustion with the load i, the fuel flow rate of the pilot burner 70 is decreased and the fuel flow rate of the main burner 80 is increased, thereby reducing the NOx emission amount.

  As described above, according to the third embodiment, the length of the air introduction hole 75 in the axial direction can be extended and lengthened, and the combustion air ejected from the air introduction hole 75 at the outlets of the air introduction holes 75 and 76. In addition, the pilot burner 70 capable of adjusting the jet direction of the air-fuel mixture is combined with the main burner 80 in which the mixing chamber 81 is extended in the axial direction, so that the ignition characteristic and the flame propagation characteristic are excellent, and the switching load of the gas turbine 1 is reduced. The gas turbine combustor 4 that can be reduced and can perform ultra-low NOx combustion at a rated load can be provided.

Example 4
A fourth embodiment of the present invention will be described below with reference to FIGS.
The burners 90 and 100 of the combustor 10 included in the gas turbine combustor 4 according to the fourth embodiment include a pilot burner 90 corresponding to the burner 30 of the second embodiment and a main burner 100.
The pilot burner 90 has a mixing chamber wall 92 that forms a mixing chamber 91 that opens toward the combustion chamber 20 in the axial direction, and fuel nozzles 98 and 99 that supply fuel. The mixing chamber wall 93 of the mixing chamber wall 92 is formed in a conical surface shape to form a conical mixing chamber 91. A plurality of air introduction holes 95 and 96 for ejecting a mixture of combustion air and fuel are arranged in the mixing chamber wall 92 so as to be arranged in two rows of the first and second rows R1 and R2 in the axial direction. A fuel nozzle 98 is disposed in the air introduction holes 95 and 96 at opposite positions on the upstream side in the axial direction. The air introduction holes 95 and 96 are formed by being deflected in the axial direction and the circumferential direction so that a swirling flow is generated in the mixing chamber 91 by the combustion air or air-fuel mixture ejected from the air introduction holes 95 and 96. ing.

The fuel nozzles 98 and 99 include a gaseous fuel nozzle 98 as a first fuel nozzle that supplies gaseous fuel as a first fuel, and a liquid fuel nozzle 99 as a first fuel nozzle that supplies liquid fuel as a second fuel. Consists of
The fuel that is gaseous fuel from the fuel supply device 41 provided in the fuel supply system 7 is supplied by being jetted into the air introduction holes 95 and 96 from the fuel nozzle 98 having the fuel manifold portion 98a.
Further, the fuel that is the liquid fuel from the fuel supply device 47 provided in the fuel supply system 7 is ejected into the mixing chamber 91 from the liquid fuel nozzle 99 installed on the upstream side of the combustion chamber 20 on the combustor axis C2. . Thus, since the fuel of each fuel nozzle 98 and 99 is supplied separately, the pilot burner 90 can perform single combustion of gaseous fuel, single combustion of liquid fuel, and mixed combustion of gaseous fuel and liquid fuel.

Six main burners 100 are arranged on the outer peripheral side with respect to the pilot burner 90 and are spaced apart in the circumferential direction by the number of six. Each main burner 100 is arranged so that a plurality of air introduction holes 105 to 107 arranged concentrically are arranged in three rows in the radial direction centering on the burner center line of the main burner 100. A fuel nozzle 109 is disposed on the upstream side of the main burner 100 to inject and supply fuel to the air introduction holes 105, 106, and 107 substantially in the same coaxial direction.
The fuel as the gaseous fuel from the fuel supply device 48 provided in the fuel supply system 7 (see FIG. 1) is supplied to the fuel nozzle 109 having the fuel manifold portion 109a, and the fuel from the fuel nozzle 109 is supplied to each air introduction hole 105-105. It is ejected into 107 and supplied.

  The combustion air is jetted into the combustion chamber 20 through the air introduction holes 105 to 107 together with the fuel jetted from the fuel nozzle 109. When the mixture of combustion air and fuel is ejected from the narrow space of the air introduction holes 105 to 107 into the wide space of the combustion chamber 20, the flow of the mixture is greatly disturbed. Is promoted in the combustion chamber 20.

In the fourth embodiment, a large number of air introduction holes 105, 106, and 107 are formed in the main burner 100, and the fuel nozzle 109 is disposed so as to correspond to each of the many air introduction holes 105 to 107. Since the fuel is dispersed in advance corresponding to the number of the large number of air introduction holes 105 to 107, the boundary area between the combustion air and the fuel is increased. For this reason, even if the axial distance to be mixed is short, mixing of combustion air and fuel is promoted, and ultra-low NOx combustion can be performed.
Generally, when the axial length of the mixing chamber 91 is long, there is a risk that a flame flows backward in the mixing chamber 91. However, the main burner 100 of the fourth embodiment mixes fuel and combustion air in the combustion chamber 20. Therefore, it is possible to avoid the risk that the flame flows back to the main burner 100.

In the fourth embodiment, as described above, since the mixing of the fuel and the combustion air is promoted, the fuel concentration of the air-fuel mixture ejected downstream of the main burner 100 is uniform and effective for low NOx combustion.
However, when premixed combustion is started by receiving thermal energy from the flame formed by the pilot burner 90, the air-fuel mixture ejected from the main burner 100 has a uniform fuel concentration and no high-concentration portion. It is conceivable that ignition is difficult and ignition characteristics are deteriorated. For this reason, unless the load of the gas turbine 1 (see FIG. 1) is increased, combustion cannot be performed in all the burners 90 and 100, and as a result, the load range for operating the gas turbine 1 may be reduced.

  Therefore, as shown in FIG. 14, in the fourth embodiment, as in the second embodiment, one or more, here, a plurality of six air introduction holes 95 constituting the first row R1 are arranged. One or more, in this case, a plurality of twelve air introduction holes 96 forming the second row R2 are formed at intervals in the circumferential direction. Therefore, the number of air introduction holes 96 is an integral multiple of the number of main burners 100.

  The air-fuel mixtures m1 and m2 from the specific air introduction holes 95a and 95b of the air introduction hole 95 are ejected toward the ignition portion 13a of the spark plug 13 and the inlet / outlet port 15a of the flame propagation pipe 15, respectively. The air-fuel mixture m3 is ejected toward the outlet of each main burner 100. As a result, the thermal energy of the flame (that is also the combustion gas) formed by the pilot burner 90 can be efficiently used for ignition, flame propagation, and further premixed flame ignition. And the switching characteristics are improved. As a result, it is possible to provide a gas turbine combustor 4 that is excellent in ignition characteristics and flame propagation characteristics, can reduce the switching load of the gas turbine 1, and can perform ultra-low NOx combustion under rated load conditions.

Further, the main burner 100 used in the fourth embodiment can be applied as a low NOx combustor for fuel containing hydrogen with a high fuel speed because the flame does not flow backward. When fuel containing hydrogen is used as fuel for gas turbines, hydrogen has a wide flammable range. Therefore, in order to avoid explosions due to ignition failure during ignition, liquid fuel (eg, light oil) is generally used for ignition and flame propagation. And then burned with hydrogen-containing fuel.
On the other hand, in the fourth embodiment, the pilot burner 90 includes both the fuel nozzle 98 for gas fuel and the fuel nozzle 99 for liquid fuel, so that single combustion with liquid fuel, mixing with liquid fuel and gas fuel are performed. Combustion and single combustion with gaseous fuel can be performed, and the ignition characteristics and flame propagation characteristics at the time of liquid fuel are also excellent. For this reason, the gas turbine combustor 4 according to the fourth embodiment is effective for a gas turbine combustor using hydrogen-containing fuel as fuel.

Hereinafter, an example in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
The mixing chamber of the burner 11 of Example 1 and the pilot burners of Examples 2 to 4 has a conical shape that expands toward the downstream of the combustor, but the downstream shape of the pilot burner is centered on a flat plate or downstream side. The projecting part may be a convex type, and the combustion air from the air introduction hole or the mixture of fuel and combustion air is supplied to the ignition part of the spark plug, the inlet / outlet of the flame propagation tube, or the outlet of the main burner for premix combustion. The jet direction of the air introduction hole of the pilot burner may be adjusted so that the heat energy of the pilot burner flame can be effectively used.
The air introduction passage may be formed by a pipe member.
Some air introduction holes other than the specific air introduction hole may not be supplied with fuel in the air introduction hole. In this case, only the combustion air is ejected into the mixing chamber. It will be.
Before the air-fuel mixture containing combustion air and fuel ejected from the specific air introduction hole reaches the ignition part 13a or the inlet / outlet 15a and its vicinity, the ignition part 13a is deflected by a deflecting means (for example, a deflector plate or a deflecting air flow). Or you may deflect | deviate so that it may point to the entrance / exit 15a and its vicinity.
The first row R1 may be a downstream row and the second row R2 may be an upstream row.
The plurality of air introduction passages may form a plurality of rows in the radial direction, and in this case as well, the same effects as when the rows are formed in the axial direction are exhibited. When the plurality of air introduction passages form three or more rows in the axial direction or the radial direction, the first and second rows of claim 2 are applied to any two rows of the plurality of rows. The
The present invention is not limited to a gas turbine for power generation, but also a gas turbine constituting a cogeneration system capable of supplying both heat and power, a gas turbine for driving a machine such as a pump / compressor, and other various gas turbine gases. Applicable to turbine combustor.

4 Gas Turbine Combustor 10 Combustor 13 Spark Plug 15 Flame Propagation Pipe 30, 50, 60, 70, 80, 90, 100 Burner 31, 51, 61, 71, 81, 91 Mixing Chamber 32, 72, 92 Mixing Chamber Wall 35, 36, 55, 56, 65, 66, 75, 76, 95, 96 Air introduction holes 38, 59, 69, 79, 89, 98, 99, 109 Fuel nozzles m1, m2, m3, m4, m5

Claims (5)

A plurality of combustors for supplying a gas turbine with combustion gas generated by combustion of a mixture of fuel and combustion air introduced from a compressor; a spark plug for igniting the mixture; and the combustors In a gas turbine combustor comprising a flame propagation tube for propagating a flame caused by combustion of the air-fuel mixture between
The combustor includes a burner having a mixing chamber wall that forms a mixing chamber that opens downstream in the axial direction of the combustor, and a fuel nozzle that supplies fuel.
The mixing chamber wall is provided with a plurality of air introduction passages for introducing combustion air into the mixing chamber together with fuel from the fuel nozzle,
A gas turbine combustor, wherein combustion air and fuel jetted from the air introduction passage to the mixing chamber flow toward at least one of the spark plug and the flame propagation pipe. The gas turbine combustor according to claim 1.
In the mixing chamber wall, a plurality of the air introduction passages are arranged in the first row and the second row in the axial direction or the radial direction,
The air introduction passage from which combustion air flowing toward the spark plug is jetted belongs to the first row,
The gas turbine combustor according to claim 1, wherein the air introduction passage through which combustion air flowing toward the flame propagation pipe is ejected belongs to the second row. 2. The gas turbine combustor according to claim 1, comprising a central burner that is the burner, and a plurality of outer peripheral burners disposed on an outer peripheral side with respect to the central burner.
The central burner has a central mixing chamber wall that is the mixing chamber wall that forms the central mixing chamber that is the mixing chamber, and a central fuel nozzle that is the fuel nozzle,
The outer peripheral burner has an outer peripheral mixing chamber wall that forms an outer peripheral mixing chamber that opens downstream in the axial direction, and an outer peripheral fuel nozzle that supplies fuel to the outer peripheral mixing chamber,
In the central mixing chamber wall, a plurality of the combustion air introduction passages are provided side by side in the first row and the second row in the axial direction,
The air introduction passage from which the combustion air flowing toward at least one of the ignition plug and the flame propagation pipe is jetted belongs to the first row,
Combustion air ejected from the air introduction passage belonging to the second row flows toward the outlet of the outer peripheral mixing chamber. The gas turbine combustor according to claim 3.
The gas turbine combustor, wherein the number of the air introduction passages constituting the second row of the central burners is an integral multiple of the number of the outer peripheral burners. The gas turbine combustor according to claim 3 or 4,
Among the first row and the second row, the number of the air introduction passages constituting the upstream row in the axial direction is six, and the number of the air introduction passages constituting the downstream row is twelve. ,
The gas turbine combustor is characterized in that the number of the outer peripheral burners is four or six.

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