JP3999645B2 - gas turbine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas turbine combustor (hereinafter also referred to as a “combustor”) and a gas turbine equipped with the gas turbine combustor, and in particular, a gas that reduces combustion vibration to achieve low NOx (nitrogen oxide). The present invention relates to a turbine combustor and a gas turbine.
[0002]
[Prior art]
Conventionally, a gas turbine has an air compressor (hereinafter sometimes referred to as a “compressor”), a combustor, and a turbine as main components, and the combustor is disposed between the compressor and the turbine that are directly connected to each other through a main shaft. Air that is a working fluid is sucked into the compressor by the rotation of the main shaft and compressed, the compressed air is introduced into the combustor and combusted with the fuel, and the high-temperature and high-pressure combustion gas is discharged to the turbine. Then, the main shaft is driven to rotate together with the turbine. Such a gas turbine is used as a driving source by connecting a generator or the like to the front end of the main shaft, and is used as a jet engine by disposing an exhaust port for injecting combustion gas in front of the turbine. The
[0003]
By the way, in recent years, reduction of NOx in exhaust gas exhausted from gas turbines has been strongly desired for environmental problems that are one of the foundations of legal regulations. For this reason, in particular, a combustor that actually generates NOx is required to have a technique for suppressing the generation of NOx. As a combustion method employed in the combustor to achieve this, combustion is performed after fuel and compressed air are mixed in advance. The premixed combustion method of making it become the mainstream. In this premixed combustion system, the fuel is dispersed in the compressed air in a uniform and lean state, so that a local increase in the combustion flame temperature can be prevented, thereby increasing the NOx that increases with an increase in the combustion flame temperature. Therefore, it becomes possible to reduce the production amount of.
[0004]
Here, a conventional gas turbine to which a premixed combustion type combustor is applied will be described with reference to FIG. The gas turbine 1 mainly includes a compressor 2, a gas turbine combustor 3, and a turbine 4. The combustor 3 is attached to a casing 5 having a cavity formed between the compressor 2 and the turbine 4, and an inner cylinder 6 having a combustion region, and a tail cylinder 7 connected to the front end of the inner cylinder 6. The outer cylinder 8 concentrically arranged with the inner cylinder 6, the pilot nozzle 9 disposed from the rear end on the axis of the inner cylinder 6, and arranged at equal intervals in the circumferential direction around the pilot nozzle 9 A plurality of main nozzles 10, a bypass duct 11 connected to the side wall of the transition piece 7 and opening to the vehicle compartment 5, a bypass valve 12 disposed in the bypass duct 11, and a bypass for adjusting the degree of opening and closing of the bypass valve 12 The valve variable mechanism 13 is configured.
[0005]
Under such a configuration, the compressed air compressed by the compressor 2 flows into the passenger compartment 5 (white arrow in the figure), and the outer peripheral surface of the inner cylinder 6 and the inner peripheral surface of the outer cylinder 8 After passing through the tubular space formed by the above, it is reversed by approximately 180 degrees (solid arrow in the figure) and introduced into the inner cylinder 6 from the rear end side. Next, fuel is injected into a pilot burner (not shown) at the front end of the pilot nozzle 9 to diffuse and burn, and is mixed with fuel injected into a main burner (not shown) at the front end of each main nozzle 10 to be premixed combustion. However, it becomes a high-temperature and high-pressure combustion gas. This combustion gas is discharged from its front end via the tail cylinder 7 and drives the turbine 4. A part of the compressed air in the passenger compartment 5 (hereinafter sometimes referred to as “bypass air”) is supplied from the bypass duct 11 into the transition piece 7, and this serves to adjust the combustion gas concentration. Fulfill.
[0006]
[Patent Document 1]
JP 2001-254634 A [Patent Document 2]
Japanese Patent Laid-Open No. 2002-174427
[Problems to be solved by the invention]
However, the above premixed combustion method is excellent in reducing NOx at first glance. However, since the flame is burned in a narrow and narrow range in a short time, the combustion energy per unit space becomes excessive and combustion vibration is likely to occur. is there. This combustion vibration is generated when a part of the combustion energy is converted into vibration energy, and is propagated as a pressure wave to resonate with an acoustic system including a casing such as a combustor and a gas turbine. In addition to causing noise, pressure fluctuations and heat generation fluctuations are induced in the combustor and the combustion state becomes unstable, resulting in inhibition of low NOx.
[0008]
In the past, with respect to such a problem of combustion vibration, normal operating conditions have been set as needed while appropriately adjusting the gas turbine to operate in a normal state while actually operating the gas turbine. Therefore, complicated adjustment work is indispensable.
[0009]
Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a gas turbine capable of reducing combustion vibration in order to stably achieve low NOx.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a gas turbine according to the present invention is arranged on the same circumference with respect to the main shaft between the air compressor and the turbine directly connected to each other by the main shaft, and between the air compressor and the turbine, A gas turbine comprising a plurality of gas turbine combustors each having a combustion body inside, and coaxial with the main shaft and outside the rear end of each cylinder and outside the vehicle compartment. A first annular tube provided, and a first throat having a predetermined length whose one end opens in an upstream region from each combustion region and each other end opens in the first annular tube. , And a first resistor having a large number of through holes is inserted into each end of the first throat . As a result, the fluid particles, which are the vibration elements of the combustion vibration generated in the combustion region, are effectively captured by the first resistors, and the air in the first annular tubes connected by the first throats. And oscillates in the vicinity of each first resistor, and its amplitude is attenuated. Thus, combustion vibration is reduced. In addition, the object which each one end of each 1st throat opens is each inner cylinder which comprises each cylinder, or each outer cylinder arrange | positioned concentrically with each inner cylinder .
[0014]
Here, since the internal space of the first annular tube connected from each combustor via each first throat is one continuous space, a phase difference of pressure fluctuation occurs in the internal space itself. There is a case. In this case, since the fluid particles do not vibrate sufficiently in the vicinity of each first resistor, the combustion vibration cannot be sufficiently reduced as it is. Therefore, from the viewpoint of suppressing the occurrence of the phase difference of the pressure fluctuation in the first annular tube and effectively vibrating the fluid particles in the vicinity of each first resistor, the respective components in the first annular tube. It is preferable to provide a first partition between the other ends of the first throat. Thus, the first annular tube is divided for each first throat, that is, for each combustor, and the occurrence of a phase difference of pressure fluctuation is suppressed.
[0015]
Further, in order to reduce combustion oscillation efficiency, desirably vibrating the fluid particles in many places, in order to achieve this, in the outer side of said first annular tube in the main shaft coaxial At least one second annular tube connected to the outside of the passenger compartment, and a predetermined opening corresponding to each of the first throats and opening into the first and second annular tubes adjacent to each other. A second throat having a length, and a second resistor having a plurality of through holes is inserted into each end located on the first annular tube side in each second throat. Good. As a result, the fluid particles resonate with the air in the second annular tube connected to each second throat in addition to the vibration near each first resistor, and near each second resistor. It vibrates and its amplitude is attenuated.
[0016]
Here, in the same manner as described above, from the viewpoint of effectively vibrating the fluid particles in the vicinity of each second resistor by suppressing the occurrence of the phase difference of the pressure fluctuation in the second annular tube, the second It is preferable to provide a second partition between the other ends of the second throats in the annular tube.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, a first embodiment of the present invention will be described. FIG. 1 is a longitudinal sectional view of an essential part schematically showing the vicinity of a combustor of a gas turbine according to a first embodiment of the present invention. In the figure, parts having the same names and performing the same functions as those in FIG. 8 are denoted by the same reference numerals, and redundant description is omitted. The same applies to the second to sixth embodiments described later.
[0018]
The combustor 3 of the present embodiment has the same basic configuration as that applied to the gas turbine 1 as shown in FIG. 8, but differs in the following points. That is, as shown in FIG. 1, the box body 50 is disposed outside the rear end wall of the outer cylinder 8, and an internal space having a predetermined volume is formed by a cavity in the box body 50. The box body 50 is connected to the rear end wall of the outer cylinder 8 via a tubular throat 51 having a predetermined length. The throat 51 has one end 51a in the outer cylinder 8, that is, above the combustion region. While opening to the basin, the other end 51 b opens to the internal space of the box 50.
[0019]
Further, a resistor 52 having a large number of through holes is inserted into one end 51 a of the throat 51. The resistor 52 is, for example, a punching metal, a ceramic sintered metal, or a sintered wire mesh.
[0020]
With such a configuration, with respect to the combustion vibration generated in the combustion region in the inner cylinder 6, the fluid particles as the vibration element propagate through the inner cylinder 6 into the outer cylinder 8, and then the resistor 52 is effectively captured. Then, it resonates with the air in the internal space of the box 50 connected by the throat 51 and vibrates in the vicinity of the resistor 52. This vibration attenuates the amplitude of the fluid particles and reduces the combustion vibration. As a result, stable reduction in NOx can be realized.
[0021]
In addition, the white arrow in a figure has shown the flow of the compressed air compressed with the compressor 2, and compressed air flows in into the compartment 5 first, and then the outer peripheral surface of the inner cylinder 6 and the outer cylinder 8 After passing through the tubular space formed by the inner peripheral surface of the inner tube 6, it is reversed by 180 degrees and introduced into the inner cylinder 6 from the rear end side. Then, diffusion combustion and premixed combustion are carried out together with fuel in the inner cylinder 6, and the combustion gas generated thereby is discharged from the front end toward the turbine 4 via the tail cylinder 7.
[0022]
Next, a second embodiment of the present invention will be described with reference to FIG. The feature of the second embodiment is that the structure of the box 50 in the first embodiment is simplified. This is because the internal space of the box 50 is much higher than atmospheric pressure, but as shown in FIG. 1, the box 50 itself is disposed outside the combustor 3, that is, under atmospheric pressure. This is because a significant pressure difference occurs between the inside and outside of the box body 50, and the box body 50 must have a pressure resistant structure capable of withstanding the pressure difference, and the box body 50 may be unnecessarily enlarged. .
[0023]
Therefore, in the present embodiment, the box body 50 is disposed in the passenger compartment 5. In this case, it is sufficient that the throat 51 is bent and fitted through the casing of the vehicle compartment 5. As a result, the box body 50 itself is placed in the passenger compartment 5 under a pressure almost equal to the internal space, so that there is almost no pressure difference between the inside and outside. Therefore, a special pressure-resistant structure is not required for the box 50, and the box 50 is not enlarged more than necessary.
[0024]
Next, a third embodiment of the present invention will be described with reference to FIG. The feature of the third embodiment is that the object to be opened at one end 51a of the throat 51 in the first and second embodiments is changed.
[0025]
In other words, as shown in FIG. 3, one end 51 a of the throat 51 opens into the inner cylinder 6 from a portion of the side wall of the inner cylinder 6 that is upstream of the combustion area. 3 is based on the second embodiment (see FIG. 2), and the box body 50 is changed from that disposed in the passenger compartment 5. However, of course, the first embodiment (see FIG. 1) is changed. ) May be changed. In this case, it is sufficient that the throat 51 is connected to the side wall of the inner cylinder 6 through the rear end wall or side wall of the outer cylinder 8.
[0026]
Even in such a configuration, as in the first and second embodiments, the fluid particles resonate with the air in the internal space of the box body 50 and vibrate near the resistor 52, and the amplitude thereof is attenuated.
[0027]
Note that the opening target of the one end 51 a of the throat 51 may be the side wall of the outer cylinder 8.
[0028]
Next, a fourth embodiment of the present invention will be described with reference to FIGS. The feature of the fourth embodiment is that combustion vibration is reduced while considering the practicality of the gas turbine as a whole.
[0029]
Prior to the description of the characteristic part of this embodiment, a general arrangement position of the combustor in one gas turbine will be described. As shown in FIGS. 4 and 5, the gas turbine 1 is provided with a plurality of combustors 3 mainly for the purpose of efficiently applying a rotational force to the turbine 4. Specifically, the combustors 3 are arranged at equal angular intervals on the same circumference with respect to the main shaft J that directly connects the air compressor 2 and the turbine 4 (in FIG. 5, each combustor 3 has six pitches of 60 degrees). One).
[0030]
The characteristic part of this embodiment will be described below. A first annular tube body 30 that is coaxial with the main shaft J and has an annular inner space is disposed outside the rear end wall of each outer cylinder 8. Further, the first annular tubular body 30 is connected to the rear end wall of each outer cylinder 8 via a tubular first throat 31 having a predetermined length. One end 31 a opens in each outer cylinder 8, that is, upstream in the combustion region, and each other end 31 b opens in the first annular tube 30.
[0031]
Further, a first resistor 32 having a large number of through holes is inserted into one end 31 a of the first throat 31. The first resistor 32 is, for example, a punching metal, a ceramic sintered metal, or a sintered wire mesh, like the resistor 52 in the first to third embodiments.
[0032]
According to such a configuration, fluid particles that are vibration elements of combustion vibration generated in the combustion region in each inner cylinder 6 are effectively captured by each first resistor 32 and each first throat. Resonates with the air in the first annular tube 30 connected at 31, and vibrates in the vicinity of each first resistor 32. By this vibration, the amplitude of the fluid particles in each combustor 3 is attenuated, and the combustion vibration is reduced. As a result, stable reduction of NOx can be realized as a whole gas turbine, and thereby reduction of NOx in the exhaust gas can be achieved.
[0033]
Next, a fifth embodiment of the present invention will be described with reference to FIG. The feature of the fifth embodiment is that the fluid particles are vibrated more effectively in the vicinity of the first resistors 32 in the fourth embodiment. This is because the internal space of the first annular tube 30 in the fourth embodiment is one continuous space, and therefore there may be a phase difference of pressure fluctuations in the internal space itself. This is because the fluid particles do not vibrate sufficiently in the vicinity of one resistor 32, and combustion vibration cannot be sufficiently reduced as it is.
[0034]
Therefore, in the present embodiment, as shown in FIG. 6, first partition walls 35 are provided between the other ends 31 b of the first throats 31 in the first annular tube 30. .
[0035]
In this way, the internal space of the first annular tube 30 that was one continuous space is divided by the first partition wall 35 for each first throat 31, that is, for each combustor 3. Occurrence of the phase difference of the pressure fluctuation in the space can be suppressed. Therefore, since the fluid particles effectively vibrate in the vicinity of each first resistor 32, the combustion vibration can be sufficiently reduced.
[0036]
Finally, a sixth embodiment of the present invention will be described with reference to FIG. The feature of the sixth embodiment is that the combustion vibration in the fourth and fifth embodiments is efficiently reduced.
[0037]
That is, in the present embodiment, as shown in FIG. 7, the second annular tube 40 that is coaxial with the main shaft J and has an annular inner space is connected to the outside of the first annular tube 30. It is installed. The second annular tubular body 40 is connected to the first annular tubular body 30 via a tubular second throat 41 having a predetermined length and corresponding to each first throat 31. Each of the second throats 41 has one end 41a located on the first annular tube 30 side opening in the first annular tube 30 and each other located on the second annular tube 40 side. The end 41 b opens into the second annular tube 40.
[0038]
Furthermore, a second resistor 42 having a large number of through holes is inserted into each end 41 a of each second throat 41. Similar to the first resistor 32, these second resistors 42 are, for example, a punching metal, a ceramic sintered metal, and a sintered wire mesh.
[0039]
According to such a configuration, the fluid particles resonate with the air in the second annular tube 40 connected by the second throat 41 in addition to the vibration in the vicinity of each first resistor 32. Thus, it vibrates in the vicinity of each second resistor 42 and its amplitude is attenuated. Therefore, the fluid particles can be vibrated at many locations, and the combustion vibration can be efficiently reduced.
[0040]
In FIG. 7, one second annular tube 40 is connected to the first annular tube 30, but two or more may be connected as a matter of course. In this case, it is sufficient to connect the adjacent second annular tubular bodies 40 with the second throat 41 described above.
[0041]
Further, for the same purpose as in the fifth embodiment, a second partition wall (not shown) may be provided between each other end 41b of each second throat 41 in the second annular tubular body 40. . In this way, the internal space of the second annular tubular body 40 that was one continuous space is formed by the second partition wall for each second throat 41, that is, for each combustor 3 that passes through the first throat 31. By dividing, the occurrence of a phase difference of pressure fluctuations in these individual divided spaces is suppressed. Therefore, since the fluid particles effectively vibrate in the vicinity of each second resistor 42, the combustion vibration can be further sufficiently reduced in combination with the vibration of the fluid particles in the vicinity of each first resistor 32.
[0042]
Furthermore, the opening target of the one end 31a of each first throat 31 may be the side wall of the inner cylinder 6 or the side wall of the outer cylinder 8 as long as it is a portion upstream of the combustion area.
[0043]
In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the cross-sectional shape of the throat 51, the first throat 31, and the second throat 41 is not limited to a circle and may be a polygon.
[0044]
【The invention's effect】
As described above , according to the gas turbine of the present invention, the air compressor and the turbine directly connected to each other by the main shaft, and the air compressor and the turbine are arranged on the same circumference with respect to the main shaft, A gas turbine comprising a plurality of gas turbine combustors each having a combustion body inside, and coaxial with the main shaft and outside the rear end of each cylinder and outside the vehicle compartment. A first annular tube provided, and a first throat having a predetermined length whose one end opens in an upstream region from each combustion region and each other end opens in the first annular tube. The first resistor having a large number of through holes is inserted into each one end of each first throat, so that the fluid particles that are the vibration elements of the combustion vibration generated in the combustion region are When effectively captured by each first resistor To, and resonates with the air of the first annular pipe body connected at each of the first throat, and oscillates about the first resistor, its amplitude is attenuated. In this way, it is possible to reduce the combustion vibration, and as a result, it is possible to realize a stable reduction in NOx for the entire gas turbine , thereby achieving a reduction in NOx in the exhaust gas .
[0048]
Here, when a first partition is provided between the other ends of the first throats in the first annular tube, the first annular tube, which is one continuous space, is provided. The internal space is divided by the first partition wall for each first throat, that is, for each combustor, and generation of a phase difference of pressure fluctuation in each of the divided spaces is suppressed. Therefore, since the fluid particles effectively vibrate in the vicinity of each first resistor, the combustion vibration can be sufficiently reduced.
[0049]
And a second annular tube that is coaxial with the main shaft and is outside the first annular tube and connected to the outside of the passenger compartment, and corresponds to each of the first throats. A second throat having a predetermined length opening in each of the first and second annular tubes adjacent to each other, and each of the second throats positioned on the first annular tube side. When a second resistor having a large number of through-holes is inserted into one end, the fluid particles are coupled to each second throat in addition to vibration in the vicinity of each first resistor. Resonates with the air in the annular tube and vibrates in the vicinity of each second resistor, and the amplitude is attenuated. Accordingly, the fluid particles can be vibrated at many locations, and combustion vibration can be efficiently reduced.
[0050]
Here, when a second partition is provided between the other ends of the second throats in the second annular tube, the second annular tube, which is one continuous space, is provided. The internal space is divided by the second partition wall for each second throat, that is, for each combustor that passes through the first throat, and the occurrence of a phase difference of pressure fluctuations in each of the divided spaces is suppressed. Therefore, similarly to the above, since the fluid particles effectively vibrate in the vicinity of each second resistor, the combustion vibration can be more sufficiently reduced in combination with the vibration of the fluid particles in the vicinity of each first resistor.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part schematically showing the vicinity of a combustor of a gas turbine according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of an essential part schematically showing the vicinity of a combustor of a gas turbine according to a second embodiment of the present invention.
FIG. 3 is a longitudinal sectional view of an essential part schematically showing the vicinity of a combustor of a gas turbine according to a third embodiment of the present invention.
FIG. 4 is a longitudinal sectional view of an essential part schematically showing the vicinity of a combustor of a gas turbine according to a fourth embodiment of the present invention.
FIG. 5 is a cross-sectional view of an essential part schematically showing the vicinity of a combustor of a gas turbine according to a fourth embodiment.
FIG. 6 is a main part cross-sectional view schematically showing the vicinity of a combustor of a gas turbine according to a fifth embodiment of the present invention.
FIG. 7 is an essential part longitudinal sectional view schematically showing the vicinity of a combustor of a gas turbine according to a sixth embodiment of the present invention.
FIG. 8 is a longitudinal sectional view of an essential part in the vicinity of a combustor of a general gas turbine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Compressor 3 Gas turbine combustor 4 Turbine 5 Casing 6 Inner cylinder 7 Outer cylinder 8 Outer cylinder 9 Pilot nozzle 10 Main nozzle 11 Bypass duct 12 Bypass valve 13 Bypass valve variable mechanism 30 1st annular pipe 31 First throat 31a First throat one end 31b First throat other end 32 First resistor 35 First partition 40 Second annular tube 41 Second throat 41a Second throat one end 41b The other end 42 of the second throat The second resistor 50 The box 51 The throat 51a The one end 51b of the throat The other end 52 of the throat 52 The resistor J The main shaft of the gas turbine

Claims (4)

A plurality of gases comprising an air compressor and a turbine directly connected to each other by a main shaft, and a cylindrical body disposed between the air compressor and the turbine on the same circumference with respect to the main shaft and each having a combustion region therein A gas turbine comprising a turbine combustor,
A first annular tube disposed coaxially with the main shaft and outside the rear end of each cylindrical body and disposed outside the vehicle compartment, and each end opening upstream of each combustion region A first throat having a predetermined length that opens at the other end into the first annular tube, and having a plurality of through holes at each end of the first throat. A gas turbine in which is inserted . 2. The gas turbine according to claim 1, wherein a first partition is provided between the other ends of the first throats in the first annular tube . A second annular tube that is coaxial with the main shaft and is outside the first annular tube and connected to the outside of the passenger compartment, corresponds to each of the first throats, and A second throat having a predetermined length opening in each of the first and second annular pipes adjacent to each other, and at each end located on the first annular pipe side in each second throat. The gas turbine according to claim 1 or 2, wherein a second resistor having a large number of through holes is inserted . The gas turbine according to claim 3, wherein a second partition wall is provided between the other ends of the second throats in the second annular tube .

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