JP5372228B2 - Combustor and gas turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustor capable of reducing combustion vibration dispatched while rotating in the cross-section inner circumferential direction of a swirler, in the combustor such as a double swirler combustor. <P>SOLUTION: The combustor which includes an inside swirler 20 where an inside vane 23 and a fuel supply part 22 are evenly arranged in the inside of an inner cylinder 11, and is configured so that a fuel supply condition may be almost uniform in the cross-section inner circumferential direction of the inside swirler 20 is provided with a fuel heterogeneity part Fc for the purpose of making the heterogeneous setting of the fuel supply condition in advance in part of the cross-section inner circumferential direction where the fuel heterogeneity part Fc is a feature change fuel supply hole with different fuel supply features installed in a part of the fuel supply part 22. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a combustor and a gas turbine including the combustor, and more particularly to a technique for reducing combustion vibration of a gas turbine combustor.

A gas turbine is a device having a compressor, a combustor (gas turbine combustor), and a turbine as main components.
The compressor takes in air and compresses it, and discharges high-pressure compressed air. The compressed air discharged from the compressor is taken into the combustor as combustion air, and combusted together with the fuel supplied to the combustor to become high-temperature combustion gas. This combustion gas is taken into the turbine, and the turbine is driven by the combustion gas flowing between the moving blade and the stationary blade.
In such a gas turbine, when the fuel is burned, combustion vibration may be generated in the combustor. In order to stably operate the gas turbine plant, it is desired to effectively suppress the combustion vibration of the combustor.

A double swirler combustor (hereinafter abbreviated as “combustor”) 10 shown in FIG. 8 is a gas turbine combustor including an inner swirler 20 and an outer swirler 30 disposed inside an inner cylinder 11. The inner swirler 20 and the outer swirler 30 are air passages having a double ring-shaped cross section formed coaxially with the axial center of the inner cylinder 11, and are supplied from the compressor as combustion air for burning fuel. A flow path for flowing compressed air. Reference numeral 12 in the figure denotes a combustion chamber formed in the tail cylinder 13.
Inside the inner swirler 20 and the outer swirler 30, fuel supply portions 22 and 32 having a large number of fuel injection holes 21 and 31 are installed, and on the downstream side, a large number of swirl vanes (hereinafter referred to as “ 23 and 33 are arranged in the circumferential direction.

In the combustor 10 configured as described above, the vane 23 in the inner swirler 20 and the vane 33 in the outer swirler 30 have the same shape in the circumferential direction, and accordingly, the fuel concentration (the amount of heat generation) of the combustor 10 and The degree of fuel mixing is uniform in the inner circumferential direction of the cross section. Thus, uniformization of the fuel supply state such as the fuel concentration and the fuel mixing degree is effective in reducing nitrogen oxides in the combustion gas.
However, in the inner swirler 20 and the outer swirler 30 in which the fuel supply state is made uniform, a local and dynamic high heat source H is generated under the influence of the dynamic downstream, and this is caused by the high heat source H. There is concern about the occurrence of combustion vibration. Since this combustion vibration causes damage due to noise of the combustor 10 or high cycle fatigue, a countermeasure for reducing the combustion vibration is required.

Regarding combustion vibration of a gas turbine combustor, there are the following prior arts.
The gas turbine combustor disclosed in Patent Document 1 relates to a reduction in the influence of pressure fluctuations propagated from the downstream side by providing a narrow portion in the fuel flow path. It is different from reduction.
The combustor of Patent Document 2 discloses a countermeasure against combustion vibration in which a perforated plate is installed in a multi-premixed combustor, and is not related to a double swirler combustor.

Japanese Patent No. 3494753 JP 2008-180445 A

As described above, in the inner swirler 20 and the outer swirler 30 of the combustor 10, as shown in FIG. 8, for example, the local and dynamic high heat source H is affected by the dynamic combustion chamber 12. And combustion vibration is generated under the influence of the high heat source H.
In this combustion vibration, a vibration mode (relatively high cycle) transmitted while rotating in the circumferential direction in the cross section of the inner swirler 20 and the outer swirler 30 has also been confirmed. For example, as shown in FIG. There are secondary and quaternary vibration modes in which positive pressure (+) and negative pressure (-) are alternately generated in the direction of movement.

The above-described combustion vibration causes damage to the gas turbine combustor due to noise and high cycle fatigue. Therefore, the gas turbine combustor that has taken measures to reduce the combustion vibration and the gas turbine equipped with this combustor Development is desired.
The present invention has been made in view of the above circumstances, and the object of the present invention is to reduce the combustion vibration transmitted while rotating in the inner circumferential direction of the swirler in a combustor such as a double swirler combustor. An object of the present invention is to provide a combustor that can be used, and a gas turbine including the combustor.

In order to solve the above problems, the present invention employs the following means.
The combustor according to the present invention includes a swirler in which the swirl vanes and the fuel supply portions are arranged evenly in the circumferential direction, and the fuel supply state is substantially uniform in the inner circumferential direction of the cross section of the swirler. In the combustor configured as described above, the swirler is a double swirler in which the inner swirler and the outer swirler are arranged coaxially, and the fuel supply state is set to be non-uniform in advance in a part of the inner circumferential direction of the cross section. The same number of fuel non-uniformity portions are provided in the inner swirler and the outer swirler, and the fuel non-uniformity portions are arranged with the odd number of prime numbers in the inner circumferential direction of the inner swirler and the outer swirler approximately evenly. together, are a different fuel supply characteristic changing portion of the installed fuel supply characteristics in a part of the fuel supply unit, the inner swirler and the outer scan the circumferential position of the fuel uneven portion And it is characterized in that the shift in color.

According to such a combustor, the swirler is a double swirler in which the inner swirler and the outer swirler are arranged coaxially, and the fuel for making the fuel supply state non-uniform in advance in a part of the inner circumferential direction of the cross section The same number of non-uniform portions are provided in the inner swirler and the outer swirler, and the fuel non-uniform portions are arranged so that odd numbers of prime numbers are arranged substantially evenly in the inner circumferential direction of the inner swirler and outer swirler, and the fuel supply portion Since the fuel supply characteristic changing section having different fuel supply characteristics installed in a part and the circumferential position of the fuel nonuniformity section are shifted by the inner swirler and the outer swirler, the fuel supply state in the inner circumferential direction of the cross section ( As for the distribution of the fuel concentration and the degree of fuel mixing, it is possible to intentionally form a portion that is partially non-uniform. For this reason, it becomes possible to prevent or suppress the occurrence of a local and dynamic high heat source H that is considered to be the cause of causing the combustion vibration in the inner circumferential direction of the cross section due to the dynamic downstream influence.

  In particular, since the fuel non-uniformity portion is the fuel supply characteristic changing portion, it is possible to form a fuel supply state region different from the surrounding in the inner circumferential direction of the cross section. In this case, for example, the fuel supply characteristic changing unit is provided with a portion where at least one of the number, the diameter, and the injection direction of the fuel injection holes is different in the circumferential cross section with respect to the fuel supply unit. That is, as for the fuel supply state in the circumferential cross-sectional direction, a region different from the surroundings can be formed by increasing or decreasing the fuel supply amount.

Further, the same number of fuel non-uniformity portions provided in the inner swirler and the outer swirler are arranged with the odd number of prime numbers approximately evenly in the inner circumferential direction of the cross section. As a result, the combustion mode is determined by setting the fuel supply state in the cross section of the combustor to a constant mode, so that pressure waves are less likely to overlap, and the vibration mode in the inner circumferential direction of the cross section can be reduced.

The swirler is a double swirler in which the inner swirler and the outer swirler are coaxially arranged, and the circumferential position of the fuel non-uniformity portion is shifted by the inner swirler and the outer swirler, so the downstream of the inner and outer swirlers. It is possible to prevent the vibration mode from being amplified by overlapping the generated pressure waves of different modes.

Gas turbine according to the present invention includes a compressor for compressing and introducing air, a combustor according to claim 1 which fuel is burned with air supplied from the compressor to produce a combustion gas, the combustor And a turbine that receives the supply of combustion gas from.

According to such a gas turbine of the present invention, the combustor according to claim 1, which generates combustion gas by combusting fuel with air supplied from a compressor, has a cross section in the combustor. A portion in which the distribution of the fuel supply state is nonuniform in the inner circumferential direction is intentionally formed. As a result, in the combustor of the gas turbine, it is possible to prevent or suppress the generation of a local and dynamic high heat source H that is considered to cause the combustion vibration in the inner circumferential direction of the cross section.

  According to the present invention described above, in a combustor such as a double swirler combustor, it is possible to reduce combustion vibrations transmitted while rotating in the inner circumferential direction of the swirler. That is, in the inner circumferential direction of the combustor, a high cycle in which the combustion mode in the inner circumferential direction of the cross section is fixed and rotationally oscillated by intentionally providing a part where the fuel concentration or the fuel mixing degree is uneven in part The combustion vibration of can be reduced. As a result, in the combustor and the gas turbine equipped with the combustor, a remarkable effect that noise or high cycle fatigue damage caused by combustion vibration can be suppressed or prevented can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circumferential cross-sectional view showing a reference example of a combustor according to the present invention, where (a) is a diagram showing a configuration example in which a part of vane height is lowered to make a fuel non-uniform portion, and (b) is a fuel. It is a density | concentration prediction mode conceptual diagram. It is an axial sectional view showing an important section of a double swirler combustor as an example of a combustor according to the present invention. It is a figure which shows the reference example (1st modification) of the combustor shown in FIG. 1, (a) is explanatory drawing which shows the example which changed the vane shape as a fuel nonuniformity part, (b) is the circumferential direction of a combustor It is sectional drawing. It is a figure which shows one Embodiment of the combustor which concerns on this invention, and is explanatory drawing which shows the example of a structure which varied the fuel supply characteristic in a part of fuel supply part as a fuel nonuniformity part. FIG. 6 is a view showing a modification of the combustor shown in FIG. 5 as an embodiment of the combustor according to the present invention, and is an explanatory view showing a configuration example in which the fuel injection angle is changed in a part of the fuel supply unit. . It is a figure which shows the reference example (2nd modification) of the combustor shown in FIG. 1, and is explanatory drawing which shows the structural example which installed the lattice used as a flow-path resistance change part as a fuel nonuniformity part. It is a figure which shows the reference example (3rd modification) of the combustor shown in FIG. 1, and is explanatory drawing which shows the structural example which gave the bellows process used as a flow-path resistance variable part as a fuel nonuniformity part. It is explanatory drawing which shows the structural example and subject about the conventional double swirler combustor.

Hereinafter, an embodiment of a combustor and a gas turbine of a gas turbine concerning the present invention is described based on a drawing.
A double swirler combustor (hereinafter abbreviated as “combustor”) 10 shown in FIGS. 1 and 2 is a combustor including an inner swirler 20 and an outer swirler 30 arranged inside an inner cylinder 11. . The combustor 10 includes a tail cylinder 13 that is connected to an inner cylinder 11 and forms a combustion chamber 12.

The combustor 10 is a main component of the gas turbine together with a compressor and a turbine (not shown).
That is, in a gas turbine, a compressor takes in air and compresses it, and supplies high pressure compressed air to the combustor 10 as combustion air. In the combustor 10, fuel is burned using this compressed air, and high-temperature combustion gas is generated and supplied to the turbine. Since this combustion gas drives a turbine by flowing between a moving blade and a stationary blade in the turbine, an axial output can be obtained.

The inner swirler 20 and the outer swirler 30 of the combustor 10 are air flow passages having a double ring-shaped cross section formed coaxially with the axial center of the inner cylinder 11, and are used as combustion air for burning fuel. It becomes a channel which flows the compressed air supplied from.
Inside the inner swirler 20 and the outer swirler 30, fuel supply portions 22, 32 having a large number of fuel ejection holes 21, 31 are installed. Normally, the optimum fuel concentration is determined for each swirler so that the inner swirler 20 forms a rich combustion flame and the outer swirler 30 forms a lean combustion flame. The fuel concentration of the inner swirler 20 and the outer swirler 30 is defined by the air concentration (air amount) and the fuel concentration (fuel supply amount).

A large number of swirl vanes (hereinafter referred to as “vanes”) are provided downstream of the fuel supply units 22 and 32, that is, at positions closer to the combustion chamber 12 than the fuel supply units 22 and 32 in the inner swirler 20 and the outer swirler 30. Are abbreviated in the circumferential direction. Here, the vane installed in the inner swirler 20 is called an inner vane 23, and the vane installed in the outer swirler 30 is called an outer vane 33.
The inner swirler 20 and the outer swirler 30 in which the vanes 23 and 33 and the fuel supply units 22 and 32 are evenly arranged in the circumferential direction are provided, and the fuel concentration is set to be substantially uniform in the inner circumferential direction of the swirler. In addition, in the present invention, a fuel non-uniformity portion is provided for making the fuel supply state non-uniform in advance in a part of the inner circumferential direction of the cross section.

The fuel non-uniformity portion Fa of the reference example shown in FIG. 1 is a deformed vane 23A having a vane height H lower than the other inner vanes 23 for a part of the swirl vanes installed in the inner swirler 20, that is, A deformed vane 23A having a reduced radial length is employed.
Such an irregularly shaped vane 23A can secure an air flow path having an increased flow cross-sectional area corresponding to the lower vane height H. Therefore, particularly in the inner circumferential direction of the cross section of the combustor 10, the inner swirler 20 In the inner circumferential direction of the cross section, a region (flow path) in which the pressure loss is partially reduced with respect to the air flow is formed. For this reason, since the flow rate of the air flowing through the deformed vane 23A is increased from the surrounding area (flow path) where the inner vanes 23 having the normal height are arranged, such as the fuel concentration and the fuel mixing degree. The fuel supply state becomes non-uniform in the inner circumferential direction of the cross section due to an increase in the ratio of air around the position where the deformed vane 23A exists.

The fuel non-uniformity portion Fa described above is substantially equal to the odd number of prime numbers (3, 5, 7,...), For example, as shown in FIG. It is desirable to arrange them evenly. In such a configuration, in the cross section of the combustor 10, since the fuel supply state is set to a constant mode and the combustion mode is determined, the pressure waves are difficult to overlap. The vibration mode of the direction can be reduced.
Further, in the above description, the fuel non-uniformity portion Fa is applied to the inner vane 23, but may be applied to the outer vane 33.

  In addition, the fuel non-uniformity portion Fa described above is, for example, as shown in FIG. 1B, when the combustor 10 is a double swirler in which the inner swirler 20 and the outer swirler 30 are arranged coaxially, It is preferable to shift the circumferential position of the fuel non-uniformity portion Fi and the fuel non-uniformity portion Fo of the outer swirler 30. This is a shift so that the pressure waves of the inner swirler 20 and the outer swirler 30 do not overlap, and prevents the vibration mode from being amplified when the pressure waves overlap. In the example shown in the figure, the three fuel non-uniformity portions Fi and Fo are provided and shifted by about 60 degrees in the circumferential direction. However, the present invention is not limited to this.

  FIG. 3 shows a first modification of the above-described reference example, and the vane width of a part of the inner vane 23 and / or the outer vane 33 serving as the fuel non-uniformity portion Fb is reduced by leaving the inner struts. This is an example of changing the vane shape. In this modified example, the inner vane 23 'or the outer vane, which is an irregularly shaped vane in which a part of the vane width W is removed from the inner vane 23 or the outer vane 33 having the normal vane shape shown on the left side of FIG. By changing the shape to the vane 33 ', a separation vortex is partially generated to increase the pressure loss of the flow path. In the portion where the pressure loss is increased in this way, the air supply amount such as the surroundings and the fuel concentration becomes uneven due to the decrease in the air flow rate.

  For such a fuel non-uniformity portion Fb, as in the combustor 10A shown in FIG. 3B, for example, an odd number of prime numbers are arranged substantially evenly in the inner circumferential direction of the cross section, and in the case of a double swirler. The fuel non-uniformity portions Fi and Fo of the inner swirler 20 and the outer swirler 30 are preferably arranged with their positions shifted in the circumferential direction.

  FIG. 4 shows an embodiment of a combustor according to the present invention. In the combustor 10B of the present embodiment, fuel supply characteristics are provided in a part of the fuel supply units 22 and 32 as the fuel non-uniformization unit Fc. A different configuration example is shown. That is, the fuel non-uniformity part Fc is provided with a fuel supply characteristic changing part having a different fuel supply characteristic in a part of the fuel supply parts 22 and 32 in the inner circumferential direction of the cross section.

In this case, for example, the diameter and number of the fuel injection holes 21 and 31 are partially changed to change the fuel injection amount supplied from the fuel supply parts 22 and 32 in the cross-sectional inner circumferential direction. There is something set to.
Alternatively, as a modification according to the present embodiment, as shown in FIG. 5, in the characteristic change fuel supply holes 21 </ b> A and 31 </ b> A that are part of the fuel injection holes 21 and 31, the direction in which the fuel flows out (fuel injection angle) is appropriately set. It may be set differently.
That is, as the fuel supply characteristic changing unit, it is only necessary to provide portions of the fuel supply units 22 and 32 that are different in at least one of the number, the diameter, and the injection direction of the fuel injection holes 21 and 31 in the circumferential cross section.

Providing such a fuel supply characteristic changing unit makes it possible to form a region in which the fuel supply state differs from the surroundings by increasing or decreasing the fuel supply amount because the fuel supply amount, supply direction, and the like differ in some regions.
For the above-described fuel non-uniformity portion Fc, as in the combustor 10B shown in FIG. 4, for example, the odd number of primes are arranged approximately evenly in the inner circumferential direction of the cross section, and in the case of a double swirler, It is desirable to dispose the fuel non-uniform portions Fi and Fo of the inner swirler 20 and the outer swirler 30 while shifting their positions in the circumferential direction.

  The combustor 10C of the second modified example (reference example) shown in FIG. 6 and the combustor 10D of the third modified example (reference example) shown in FIG. 7 have fuel nonuniformity in at least one of the inner swirler 20 and the outer swirler 30. A flow path resistance changing portion is provided as the control portion. This flow resistance change portion is provided only in a part of the inner circumferential direction of the cross section, like the fuel non-uniformity portion Fa described above.

  In the second modification shown in FIG. 6, a lattice 40 is installed as a fuel flow path resistance changing unit downstream of the fuel supply unit 22 in the air flow path of the inner swirler 20. The lattice 40 is a lattice-like obstacle with minute intervals that is installed in the flow path to increase flow path resistance. The flow that has passed through the lattice 40 generates minute vortices and promotes mixing of fuel and air, so the fuel concentration and the degree of fuel mixing around the lattice 40 are uneven and different from the surroundings. That is, by providing such a lattice 40, it is possible to intentionally disturb the flow by forming a minute vortex in a part of the inner circumferential direction of the cross section, so that the region of the fuel supply state different from the surroundings can be provided. Can be formed.

In the third modified example shown in FIG. 7, in the air flow path of the inner swirler 20, a bellows (bellows) processing part 50 that becomes a flow resistance variable part at a proper position on the inner wall surface of the flow path from the fuel supply part 22 to the inner vane 23. Is provided. The bellows processed portion 50 is obtained by performing bellows processing on the inner wall surface of the flow path of the inner swirler 20 to provide unevenness, and can increase the flow path resistance. For this reason, it is possible to generate vortices on the uneven wall surface of the bellows processed portion 50 and promote mixing of fuel and air. Therefore, the fuel concentration and the degree of fuel mixing around the bellows processed portion 50 are different from the surroundings. It becomes. That is, the flow can be intentionally disturbed by forming a vortex or the like in a part of the inner circumferential direction of the cross section, so that a region in a fuel supply state different from the surroundings can be formed.
In addition, the structure which provides unevenness on the flow path wall surface to make the flow path resistance variable part is not limited to the above-described bellows processed part 50, for example, an uneven wall surface formed by pressing or pasting other members, etc. Any wall surface or wall surface that can form vortices with different flow path resistances from the surroundings may be used.

6 and 7, the inner swirler 20 is provided with the lattice 40 and the bellows processed portion 50. However, such a fuel flow path resistance changing portion may be installed only on the outer swirler 30. Alternatively, it may be installed on both the inner swirler 20 and the outer swirler 30.
As for the fuel non-uniformity portion adopting the fuel flow path variable resistance portion, the odd number of primes are arranged substantially evenly in the inner circumferential direction of the cross section as in the above-described embodiments and modifications. In the case of a swirler, it is desirable to dispose the fuel non-uniform portions of the inner swirler 20 and the outer swirler 30 while shifting their positions in the circumferential direction.

  As described above, according to the combustor of the present invention and each reference example, since the fuel non-uniformity portion for setting the fuel supply state to be non-uniform in advance in a part of the inner circumferential direction of the cross section is provided, With respect to the distribution of the fuel supply state (fuel concentration and fuel mixture degree) in the circumferential direction, it is possible to intentionally form a part that is partially non-uniform. For this reason, it becomes possible to prevent or suppress the occurrence of a local and dynamic high heat source H that is considered to be the cause of causing the combustion vibration in the inner circumferential direction of the cross section due to the dynamic downstream influence.

Therefore, in the combustor of the present invention and each reference example described above, it is possible to reduce the combustion vibration that is transmitted while rotating in the inner circumferential direction of the inner swirler 20 and / or the outer swirler 30. That is, in the inner circumferential direction of the cross section of the combustor, by intentionally providing a part where the fuel supply state and the fuel concentration and the degree of fuel mixing are uneven in part, the combustion mode in the inner circumferential direction of the cross section is fixed It is possible to reduce high-cycle combustion vibration that rotates and vibrates. As a result, in the combustor and the gas turbine equipped with the combustor, a remarkable effect that noise or high cycle fatigue damage caused by combustion vibration can be suppressed or prevented can be obtained.
In addition, this invention is not limited to embodiment mentioned above, For example, it is not limited to the double swirler combustor demonstrated by embodiment, For example, it can change suitably in the range which does not deviate from the summary.

10, 10A-10D Double swirler combustor 11 Inner cylinder 20 Inner swirler 21, 31 Fuel injection hole 21A, 31A Characteristic change fuel supply hole 22, 32 Fuel supply part 23 Inner vane 23A Deformed vane 30 Outer swirler 33 Outer vane 40 Lattice 50 Bellows processing part Fa, Fb, Fc Fuel non-uniformity part

Claims (2)

In a combustor comprising a swirler in which a swirl vane and a fuel supply portion are arranged evenly in the circumferential direction are provided inside the inner cylinder, and the fuel supply state is substantially uniform in the cross-sectional inner circumferential direction of the swirler. ,
The swirler is a double swirler in which an inner swirler and an outer swirler are arranged coaxially,
Provide the same number of fuel non-uniformities in the inner swirler and the outer swirler to set the fuel supply state in advance in a part of the inner circumferential direction of the cross section,
The fuel non-uniformity portion is configured so that odd numbers of prime numbers are substantially evenly arranged in the inner circumferential direction of the inner swirler and the outer swirler, and the fuel supply characteristics provided in a part of the fuel supply portion are different. The fuel supply characteristic change unit ,
The combustor characterized in that a circumferential position of the fuel non-uniformity portion is shifted by the inner swirler and the outer swirler . A compressor that introduces and compresses air, and a combustor according to claim 1 that generates fuel by burning fuel with air supplied from the compressor, and receives supply of combustion gas from the combustor. A gas turbine comprising: a turbine.

Images