JP2005114193A - Gas turbine combustor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas turbine combustor preventing reduction of a flame holding property in a low-temperature flame holding area accompanying reduction of air-fuel premixture concentration in the vicinity of a boundary part between a premixed combustion area and the low-temperature flame holding area to improve ignition combustion performance of air-fuel premixture in the premixed combustion area. <P>SOLUTION: This gas turbine combustor has a pilot cone between a pilot nozzle provided in a central part of a body inner cylinder and a main burner covering downstream side tip parts of a plurality of main nozzles provided along a circumferential direction outside the pilot nozzle. The gas turbine combustor is provided with an air jet means jetting air to the tip part downstream side of the pilot cone, while the pilot cone is provided with a fuel jet means jetting fuel to a flame holding low velocity area formed on the tip part downstream side of the pilot cone or the vicinity thereof. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pilot nozzle provided in a central portion of a main body inner cylinder, and a main burner that covers a downstream tip portion of a plurality of main nozzles provided outside the pilot nozzle along the circumferential direction of the main body inner cylinder. The present invention relates to a gas turbine combustor including a pilot cone formed along the circumferential direction of the main body inner cylinder.

The gas turbine combustor includes a pilot nozzle provided at a central portion of a cylindrical inner cylinder, and a plurality of main nozzles provided outside the pilot nozzle along the circumferential direction of the main cylinder. A main burner that covers the downstream tip of the main nozzle and mixes with air, and a pilot cone formed between the outer periphery of the pilot nozzle and the main burner along the circumferential direction of the main body inner cylinder. It is configured.
In such a gas turbine combustor, as shown in, for example, Patent Document 1 (Japanese Patent Laid-Open No. 11-223341) and Patent Document 2 (Japanese Patent Laid-Open No. 2003-130351), downstream of the tip end portion of the pilot cone in the combustion chamber A low-temperature flame holding region that holds a high-temperature and low-speed gas region is formed on the side to maintain ignition combustion in the premixed combustion region downstream of the main burner.

FIG. 20 shows an outline of the gas turbine combustor in the vicinity of the downstream portion of the main burner and the tip of the pilot cone. In the figure, 5 is the main burner, 41 is the pilot cone, and 041 is the air (4) provided in the pilot cone 41 ( The air (air) passage, 041a is an air (air) outlet from the air passage 041 provided in the flame holding formation portion 041c at the tip of the pilot cone 41, and 10 is an inner periphery of the main burner 5 and an outer periphery of the pilot cone 41. Air (air) passages 10 a formed between them are air (air) outlets from the air passage 10.
101 is a premixed combustion region in which a premixed mixture of main fuel and main air premixed in the main burner 5 is combusted, and 100 is a portion in contact with the premixed combustion region 101 on the downstream side of the tip of the pilot cone. In this low temperature flame holding region, the ignition and combustion in the premixed combustion zone 101 is well maintained by holding the high temperature and low speed gas region in the low temperature flame holding region 100.

In the gas turbine combustor, for example, as disclosed in Patent Document 1, an air (air) passage is provided in the inner peripheral portion of the pilot cone, and the air flowing through the air passage is supplied to the tip of the pilot cone. It is configured to eject from the outer periphery of the flame-holding portion to the premixed combustion region side downstream of the main burner.
That is, in FIG. 21, which shows an outline of the main burner downstream portion and the vicinity of the pilot cone tip portion, 5a is an air ejection substrate of the main burner 5, and 5b is an air (air) ejection formed in a large number in the air ejection substrate 5a. It is a hole. 041 is an air (air) passage provided in the pilot cone 41, 041a is an air (air) outlet from the air passage 041 provided in the flame-holding portion 041c at the tip of the pilot cone 41, and 041b is the air outlet. It is a spacer constituting the diaphragm member 041a. Further, 10 is an air (air) passage formed between the inner periphery of the main burner 5 and the outer periphery of the pilot cone 41, and 10a is an air (air) outlet from the air passage 10.

JP-A-11-223341 JP 2003-130351 A

In the conventional techniques such as Patent Document 1 and Patent Document 2, that is, the conventional technique as shown in FIG. 20, the air outlet of the air passage 041 provided in the flame holding formation portion 041 c at the tip of the pilot cone 41. The air from 041a is jetted to the boundary between the premixed combustion zone 101 downstream of the main burner 5 and the low temperature flame holding zone 100 formed at a portion in contact with the inside of the premixed combustion zone 101, and The boundary portion between the premixed combustion region 101 and the low temperature flame holding region 100 by the air ejected from the air outlet 10a of the air passage 10 formed between the inner periphery of the main burner 5 and the outer periphery of the pilot cone 41. The premixed gas concentration in the vicinity tends to decrease.
For this reason, in such a conventional technique, the flame holding property of the low temperature flame holding region 100 is reduced by the decrease in the premixed gas concentration in the vicinity of the boundary between the premix combustion region 101 and the low temperature flame holding region 100 as described above. It has a problem that it deteriorates and causes the ignition combustion performance of the premixed gas in the premixed combustion zone 101 to be lowered.

Further, in the conventional technique such as Patent Document 1, that is, in the conventional technique as shown in FIG.
As described above, the air flowing through the air passage 041 provided on the inner peripheral side of the pilot cone 41 is ejected from the air ejection port 041a toward the premixed combustion region 101.
However, in such a conventional technique, the pilot fuel spray 02a ejected from a pilot nozzle (not shown) directly contacts the vicinity of the flame holding formation portion 041c at the tip of the pilot cone 41 to perform pilot combustion. increased metal temperature of-holding flame forming portion 041c near the pilot combustion by thermal contraction due to such a temperature rise, the inner and pilot air ejection port 041a outlet width S ₂ and the main burner 5 of the said air passage 041 air jet outlet 10a outlet width S ₁ of the air passage 10 formed between the outer periphery of the cone 41 is easily reduced.
Therefore, such in the conventional art, is no longer sufficient film air mass in the air jetting port 041a or 10a is obtained by reduction of the outlet width S ₂ or S ₁ of the air ejecting port 041a or 10a, such as the There is a problem in that the amount of air in the premixed combustion region 101 is insufficient and the combustion performance of the premixed gas from the main burner is reduced.

In view of the problems of the prior art, the present invention prevents premixing by preventing a decrease in the flame holding property of the low temperature flame holding region due to a decrease in the premixed gas concentration in the vicinity of the boundary between the premixed combustion region and the low temperature flame holding region. It is a first object of the present invention to provide a gas turbine combustor having improved pre-mixed gas ignition combustion performance in a combustion zone.
The second object of the present invention is to avoid a rise in the metal temperature in the vicinity of the flame-holding portion at the tip of the pilot cone, thereby reducing the passage area of the air outlet at the tip of the pilot cone and the accompanying precautions. An object of the present invention is to provide a gas turbine combustor capable of preventing a deterioration in combustion performance of an air-fuel mixture.

  The present invention achieves such an object, and the first means includes a pilot nozzle provided at the center of a cylindrically formed main body inner cylinder, and a periphery of the main body inner cylinder outside the pilot nozzle. In a gas turbine combustor comprising a pilot cone formed along a circumferential direction of the main body inner cylinder between a main burner covering a downstream tip portion of a main nozzle provided in a plurality along the direction, Air jetting means for jetting air toward the downstream side of the tip end portion of the pilot cone, and fuel jet means for jetting fuel to or near the flame holding low speed region formed on the downstream side of the tip end portion of the pilot cone The pilot cone is provided.

According to such a first means, from the fuel jetting means provided in the flame holding formation portion downstream of the pilot cone, in the vicinity of the flame holding low speed region formed on the downstream side of the flame holding formation portion, preferably the flame holding device. By ejecting fuel in the vicinity of the boundary between the low speed region and the premix combustion region on the downstream side of the main burner, the concentration of the premixed gas in the vicinity of the boundary can be increased. Thereby, the ignition combustion performance of the premixed gas in the premixed combustion zone can be improved while maintaining the flame holding performance in the flame holding low speed range.
On the other hand, since the air is ejected from the air ejection means toward the downstream side of the front end of the pilot cone, flashback from the premixed combustion region downstream of the main burner can be avoided. Further, since the fuel passage of the fuel injection means is formed in the pilot cone, the pilot cone can be cooled by the fuel flowing through the fuel passage, and overheating of the pilot cone can be avoided.

In the first means, air jet means for jetting air in the flame holding low speed region or in the vicinity thereof is preferably provided in the pilot cone on the inner peripheral side of the fuel jet means.
According to this structure, since the air jetting means is provided on the inner peripheral side of the fuel jetting means in the pilot cone, even if the fuel jetting by the fuel jetting means is interrupted, the air jetting means is provided on the inner peripheral side of the fuel jetting means. Since the pilot cone can be cooled by the air from the air jetting means, it is possible to maintain good flame holding performance while maintaining overheating of the pilot cone at all times.

In the first means, preferably, the fuel injection portion of the fuel injection means is constituted by a plurality of fuel injection holes formed along the circumferential direction of the main body inner cylinder.
With this configuration, since the fuel outlet of the fuel injection portion of the pilot cone is configured with a plurality of fuel injection holes, the area of the fuel injection portion outlet caused by thermal deformation or the like in the vicinity of the fuel injection portion of the pilot cone is reduced. Uniformity can be avoided.

In the first means, preferably, a fuel jet passage constituting the fuel jet means is formed partway along the pilot cone, and a fuel jet outlet from the fuel jet passage is opened inside the pilot cone.
If comprised in this way, the flame-holding low-speed area | region will be made into the air-fuel mixture which the fuel jetted inside the pilot cone from the fuel outlet provided in the middle of the pilot cone, and the pilot air which flows inside the pilot cone mix. By making it flow into the flame, it is possible to improve the flame holding property in the flame holding low speed region.
In addition, since fuel and pilot air flowing inside the pilot cone are partially premixed in the middle of the pilot cone, NOx is generated in the premixed combustion zone while improving flame holding performance in the flame holding low speed region. The amount can be reduced.
In addition, if the pilot cone is formed so as to protrude inside the pilot cone and the inside thereof is connected to the fuel injection passage, the fuel injection port is provided in the protrusion, and the fuel is supplied. By passing through the projection, excessive flow of fuel to the pilot air side can be suppressed, and the premixed gas can smoothly flow into the flame holding low speed region.

  Further, the pilot cone is formed by an upstream cone located upstream and a downstream cone connected to the downstream side of the upstream cone and having a larger opening angle than the upstream cone. If the fuel injection port is configured to open in the vicinity of the connection portion between the upstream cone and the downstream cone, there is no projection as described above, so that damage to the pilot cone due to overheating of the projection can be avoided. To improve flame holding performance by flowing a mixture of pilot fuel and pilot air jetted inside the pilot cone into the flame holding low speed region while avoiding an increase in flow resistance in the pilot air flow path Can do.

Next, the second means of the present invention includes a pilot nozzle provided at the center of a cylindrical inner cylinder, and a plurality of pilot nozzles outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor comprising a pilot cone formed along a circumferential direction of the main body inner cylinder between a main burner covering a downstream end portion of the provided main nozzle and corresponding to the main nozzle. And a fuel ejection means for ejecting fuel between the main swirlers.
According to the second means, since the fuel is ejected between the main swirlers, the fuel is ejected into the stagnation region between the swirling flows by the main swirler, so that the stagnation region becomes a flame-holding point and has a flame-holding property. Will improve. Moreover, since fuel is ejected from the exit end face of the main swirler, flashback from the combustion zone is not caused.

In the second means, preferably, a fuel ejection passage constituting the fuel ejection means is partitioned into a plurality of chambers along the circumferential direction of the main body inner cylinder, and at least one of the plurality of chambers is separated from the plurality of chambers. The other fuel injection port is opened so as to eject the fuel to or near the flame holding low speed region.
If comprised in this way, the fuel injection port which injects a fuel between main swirlers, and the fuel injection port which injects a fuel to a flame-holding low speed area or its vicinity in the separate fuel injection passage formed in multiple chambers Since it is provided, it is possible to adjust the distribution between the amount of fuel ejected to the stagnation portion between the main swirler and the amount of fuel ejected to the flame holding low speed region or in the vicinity thereof to an optimum distribution.

Next, the third means of the present invention includes a pilot nozzle provided at the center of a cylindrical inner cylinder, and a plurality of pilot nozzles outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor comprising a pilot cone formed along a circumferential direction of the main body inner cylinder between a main burner that covers a downstream tip portion of a provided main nozzle, the pilot cone includes the pilot cone, Air jetting means comprising an upstream passage parallel to the pilot nozzle and a downstream passage extending in a direction perpendicular to the main burner side is provided outside the pilot nozzle, and the air jetting means The air outlet is opened so as to inject air into the premixed combustion region downstream of the main burner.
According to the third means, the pilot air is injected into the premixed combustion region on the downstream side of the main burner, so that the premixed combustion region is diluted and premixed combustion with reduced NOx generation amount is possible. Become. In addition, since a large circulating flow is formed by the pilot air in the low-speed flame holding region, flame holding properties are improved.

  Next, a fourth means of the present invention includes a pilot nozzle provided at the center of a cylindrical inner cylinder, and a plurality of pilot nozzles outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor comprising a pilot cone formed along a circumferential direction of the main body inner cylinder between a main burner covering a downstream end portion of a provided main nozzle, the pilot cone has a thick wall A thick-walled portion is formed, an air passage is formed between an outer periphery of the thick-walled portion and the main burner, and an air outlet of the air passage is connected to a premixed combustion region downstream of the main burner. It is characterized by having an opening.

  According to the fourth means, the rigidity is increased by forming the pilot cone thick, and the air formed between the outer periphery of the thick part and the main burner due to thermal deformation of the pilot cone or the like. The passage area of the air outlet in the passage can be prevented from being reduced, and the reduction of the film air amount to the premixed combustion area downstream of the main burner and the resulting reduction in the combustion performance of the premixed gas can be prevented. it can.

Preferably, in the fourth means, an air passage is formed inside the thick portion, and an air outlet of the air passage is opened to a premixed combustion region on the downstream side of the main burner.
With this configuration, the thick-walled portion is highly rigid, and the thick-walled portion is cooled by the air flowing through the air passage, whereby deformation of the pilot cone is suppressed. Reduction of the passage area of the air outlet of the air passage formed on the inner peripheral side of the portion can be prevented more reliably.

Next, a fifth means of the present invention includes a pilot nozzle provided at the center of a cylindrical inner cylinder, and a plurality of pilot nozzles outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor comprising a pilot cone formed along a circumferential direction of the main body inner cylinder between a main burner covering a downstream tip portion of a provided main nozzle, an inner circumference of the pilot cone An air passage is provided on the side of the main burner, and a first air passage is provided in the inner peripheral portion of the main burner via a space portion, the air outlet being opened to a premixed combustion region on the downstream side of the main burner. Features.
According to the fifth means, since the air passage side provided on the inner peripheral side of the pilot cone is easily deformed toward the inner side of the pilot cone, the deformation is provided on the inner peripheral portion of the main burner. In addition, the air outlet of the first air passage can be prevented from being blocked, and the film air can be reliably supplied from the first air passage to the premixed combustion region on the downstream side of the main burner.

Preferably, in the fifth means, a second air passage having an air outlet opening to a premixed combustion region downstream of the main burner is additionally provided at an outer peripheral portion of the main burner.
If comprised in this way, since the air passage was provided in two places, the inner peripheral part and outer peripheral part of a main burner, the said pilot cone deform | transforms and the film air from the air passage provided in the pilot cone inner peripheral side is provided. Even if the ejection is interrupted, the film air can be reliably supplied from the two air passages to the premixed combustion zone downstream of the main burner.

Preferably, in the fifth means, an air outlet of the air passage provided in the pilot cone is opened to the inside of the pilot cone, and an air outlet is provided downstream of the main burner at an outer peripheral portion of the main burner. A second air passage is opened in the premixed combustion zone.
If comprised in this way, while being able to supply film air to the premixing combustion area of the main burner downstream from the air passage provided in two places, the inner circumference part and the outer circumference part of the main burner, on the inner circumference side of the pilot cone Since the provided air passage side is easily deformed toward the inner side of the pilot cone, it is possible to prevent the air outlet of the air passage at the inner peripheral portion of the main burner from being blocked by such deformation, and from the two air passages. Film air can be supplied reliably.

In the fifth means, an escape hole that opens to the flame holding portion is preferably provided in the middle of the air passage provided in the pilot cone.
With this configuration, at the time of partial load operation in which the amount of deformation of the pilot cone is increased by pilot combustion, a part of the film air is released from the escape hole to the flame holding low speed region, so that the high temperature portion at the tip of the pilot cone is Cooling can avoid overheating of the pilot cone.

  According to a sixth means of the present invention, the pilot nozzle includes a first fuel outlet having a small fuel injection angle, and a second fuel outlet having a larger injection angle than the first fuel outlet. And is configured to be able to switch between the first fuel injection port during partial load operation below a certain load and the second fuel injection port during high load operation exceeding the certain load. To do.

According to the sixth means, at the time of partial load operation in which the pilot ratio (pilot combustion ratio) is large and the pilot cone is at a high temperature, the pilot fuel is ejected from the first fuel outlet having a small fuel injection angle. By preventing the pilot spray from hitting the pilot cone, overheating of the pilot cone can be suppressed.
Also, during high load operation where the pilot ratio is relatively small and the temperature increase of the pilot cone is small, the pilot fuel is ejected from the second fuel ejection port having a large fuel ejection angle, and the pilot fuel is supplied to the flame holding low speed region. By doing so, good flame holding properties can be maintained.

  According to a seventh aspect of the present invention, the pilot cone is fixed to an outer cone having an air passage whose air outlet is opened to a premixed combustion area downstream of the main burner and an inner periphery of the outer cone. And a fuel jet direction of the fuel jet port of the pilot nozzle is set so that the fuel jetted from the fuel jet port first hits the inner cone. .

  According to the seventh means, since the pilot flame caused by the fuel spray from the pilot nozzle hits the inner cone and then flows to the flame holding low speed region formed on the downstream side of the outer cone, the outer cone constituting the flame holder is formed. It is possible to prevent the pilot flame from hitting directly and to prevent the outer cone from overheating. Further, the inner cone is cooled by being exposed to pilot air, so that it is not overheated by direct contact with the pilot flame.

According to the present invention, in the gas turbine combustor, while avoiding flashback from the premixed combustion region on the downstream side of the main burner by ejecting air from the air ejection means toward the downstream side of the tip portion of the pilot cone,
The concentration of the premixed gas in the vicinity of the boundary between the flame holding low speed region and the premixed combustion region is determined by jetting fuel from the fuel injection means provided in the flame holding formation portion downstream of the pilot cone to the flame holding low speed region. It is possible to raise the temperature, and the flame holding performance in the flame holding low speed range can be maintained well, and the ignition combustion performance of the premixed gas in the premixed combustion zone can be improved.

In addition, since the fuel passage of the fuel injection means can be formed in the pilot cone, the pilot cone can be cooled by the fuel flowing through the fuel passage, and overheating of the pilot cone can be avoided.
In addition, according to the present invention, by increasing the rigidity of the pilot cone or avoiding overheating due to an increase in the temperature of the pilot cone, it is possible to avoid blockage of the air passage to the premix combustion region downstream of the main burner. A sufficient amount of film air can be constantly supplied to the mixed combustion zone to prevent flashback.

  Hereinafter, the present invention will be described in detail using embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

FIG. 1 is an enlarged view of a Y portion in FIG. 18 showing a schematic configuration in the vicinity of a flame holding low speed region and a premixed combustion region of a gas turbine combustor according to a first embodiment of the present invention. FIG. 2 is a view corresponding to FIG. 1 showing the second embodiment, FIG. 3 is a view showing the third embodiment, (A) is a view corresponding to FIG. 1, and (B) is a view taken in the direction of arrow B in (A). 4 is a diagram corresponding to FIG. 1 showing the fourth embodiment, FIG. 5 is a diagram corresponding to FIG. 1 showing the fifth embodiment, and FIG. 6 is a diagram corresponding to FIG. FIG. 7 is a view taken in the direction of the arrow W in FIG. 18 showing the seventh embodiment. FIG. 8 is a view taken in the direction of the arrow U in FIG. 18 showing the eighth embodiment. FIG. 9 is a block diagram corresponding to FIG.
FIG. 10 is an enlarged cross-sectional view of the Y part of FIG. 18 showing the tenth embodiment. 11 is a diagram corresponding to FIG. 10 showing the eleventh embodiment, FIG. 12 is a diagram corresponding to FIG. 10 showing the twelfth embodiment, FIG. 13 is a diagram corresponding to FIG. 10 showing the thirteenth embodiment, and FIG. FIG. 15 is a diagram corresponding to FIG. 10 showing the fifteenth embodiment, FIG. 16 is a diagram corresponding to FIG. 10 showing the sixteenth embodiment, and FIG. 17 is a diagram corresponding to FIG. FIG. 18 is a schematic cross-sectional view of a tip portion of a combustor of a gas turbine combustor to which the present invention is applied, and FIG. 19 is an external view showing a schematic configuration of the gas turbine combustor.

  18 and 19 showing a schematic configuration of a gas turbine combustor to which the present invention is applied, 1 is a main body cylinder formed in a cylindrical shape, 2 is a pilot nozzle provided at the center of the main body inner cylinder 1, 3 is a plurality of main nozzles provided outside the pilot nozzle 2 at equal intervals along the circumferential direction of the main body inner cylinder 1, and 5 is a fuel from the main nozzle that covers the downstream end of the main nozzle 3. And a main burner for mixing with the main air. Reference numeral 11 denotes a pilot air passage formed in contact with the outer periphery of the pilot nozzle 2 and through which pilot air flows. Reference numeral 10a denotes a main air passage formed around the main nozzle 3 through which main air flows.

  A pilot swirler 6 is installed in the pilot air passage 11 at equal intervals in the circumferential direction so as to generate a swirl (vortex) in the pilot air flowing through the pilot air passage 11 and is ejected from the pilot nozzle 2. It promotes mixing with pilot fuel. A plurality of main swirlers 7 are installed in the main air passage 10a at equal intervals in the circumferential direction to cause a swirl (vortex) in the main air flowing through the main air passage 10a, and are ejected from the main nozzle pilot nozzle 3. It promotes mixing with the main fuel.

Reference numeral 41 denotes a pilot cone that covers the outside of the pilot air passage 11 and has a tip that expands into a cone (conical shape). Reference numeral 041 denotes a flame holding formation portion, which is formed by extending the tip portion of the pilot cone 41 in the radial direction, and has a flame holding low speed region in which a flame holding high temperature gas stays on the downstream side of the flame holding formation portion 041. It is formed.
Reference numeral 9 denotes a main cone that covers the inner peripheral side of the main air passage 10a. Reference numeral 10 denotes an air passage formed between the outer periphery of the pilot cone 41 and the inner periphery of the main cone 9, and the film air flowing through the air passage 10 is introduced into the premixed combustion zone 101 from the air outlet 10a. The flashback from the premixed combustion zone 101 side is suppressed by ejecting to the front.

  In the gas turbine combustor shown in FIGS. 18 to 19, the present invention can improve the flame holding performance in the flame holding low speed region, suppress the deformation of the pilot cone tip, and can always sufficiently supply the film air. It is what I did.

In FIG. 1 showing the first embodiment of the present invention, 5 is a main burner, 41 is a pilot cone, 51 is a fuel passage constituting fuel injection means provided in the pilot cone 41, and the tip of the fuel passage 51 Is provided with a flame holding portion 041 extending in the radial direction. The fuel injection port 51 a of the fuel passage 51 is directed so as to inject fuel to the boundary portion between the premixed combustion region 101 and the flame holding low speed region 100.
Reference numeral 10 denotes an air passage formed between the outer periphery of the pilot cone 41 and the inner periphery of the main cone 9, and the film air flowing through the air passage 10 is introduced into the premixed combustion zone 101 from an air outlet 10a. By ejecting, flashback from the premixed combustion zone 101 side is suppressed.

According to the first embodiment, the flame holding low speed region 100 and the main burner formed on the downstream side of the flame holding formation portion 041 from the fuel injection port 51a provided in the flame holding forming portion 041 downstream of the pilot cone 41. 5 By ejecting fuel in the vicinity of the boundary with the premixed combustion region 101 on the downstream side, the concentration of the premixed gas in the vicinity of the boundary is increased. Thereby, the flame holding property in the flame holding low speed region 100 can be maintained satisfactorily, and the ignition combustion performance of the premixed gas in the premixed combustion region 101 is improved.
Further, since the fuel passage 51 is formed in the pilot cone 41, the pilot cone 41 can be cooled by the fuel flowing through the fuel passage 51, and overheating of the pilot cone 41 is avoided. Further, as described above, since the film air flowing through the air passage 10 is jetted from the air outlet 10a into the premixed combustion zone 101, flashback from the premixed combustion zone 101 side can be suppressed.
1 to 17, the fuel flow is indicated by solid arrows, and the air flow is indicated by broken arrows.

In the second embodiment shown in FIG. 2, the pilot cone 41 is formed in a double cone having an air passage 52 provided on the inner peripheral side of the fuel passage 51, so that the fuel outlet 51 a and the air passage 52 are formed. The air outlets 52a communicated with each other are arranged in parallel so that fuel and air are jetted in the vicinity of the boundary between the flame holding low speed region 100 and the premixed combustion region 101.
According to the second embodiment, since the air passage 52 is provided on the inner peripheral side of the fuel passage 51 in the pilot cone 41, even if the ejection of fuel from the fuel passage 51 is shut off, Since the pilot cone 41 can be cooled by air, good flame holding properties can be maintained while the pilot cone 41 is always kept overheated.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

In the third embodiment shown in FIG. 3, instead of the fuel passage 51 in the first embodiment, a plurality of fuel jets that are continuously opened at the front end portion along the circumferential direction of the main body inner cylinder 1 A fuel passage 54 having a hole 54 a is provided in the pilot cone 41.
According to the third embodiment, since the fuel outlet of the fuel passage 54 in the pilot cone 41 is constituted by the plurality of fuel injection holes 54a, the vicinity of the fuel injection hole 54a of the pilot cone 41 that is at a high temperature. This makes it possible to avoid the non-uniformity of the fuel ejection outlet area due to thermal deformation of the fuel.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

  In the fourth embodiment shown in FIG. 4, the fuel passage 58 on the inner periphery of the pilot cone 41 is formed partway along the pilot cone 41, and the fuel injection hole 58 a from the fuel passage 58 is formed on the inner peripheral side of the pilot cone 41. Is open. The pilot cone 41 is provided with an air passage 59 adjacent to the outside of the fuel passage 58, and the air passage 59 air ejection hole 59 a is a boundary portion between the premixed combustion region 101 and the flame holding low speed region 100. Oriented to blow out air.

According to the fourth embodiment, the fuel jetted from the fuel jet hole 58a provided in the middle of the pilot cone 41 to the inside of the pilot cone 41 and the pilot air flowing inside the pilot cone 41 are mixed. It is possible to allow the gas to flow into the flame holding low speed region 100, thereby improving the flame holding performance in the flame holding low speed region 100.
Further, since the fuel from the fuel injection hole 58a and the pilot air flowing inside the pilot cone 41 are partially premixed in the middle of the pilot cone 41, the flame holding performance in the flame holding low speed region 100 is improved. In addition, the amount of NOx generated in the premixed combustion region 101 can be reduced.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

In the fifth embodiment shown in FIG. 5, a protrusion 60 projecting inside the pilot cone 41 and communicating with the fuel passage 58 at the fuel outlet in the fourth embodiment (FIG. 4). The fuel is ejected from the fuel ejection hole 58a opened in the projection 60 toward the flame holding low speed region 100 side.
According to the fifth embodiment, by allowing the fuel to pass through the protrusion 60, excessive flow of the fuel to the pilot air side can be suppressed, and the premixed gas formed on the downstream side of the pilot cone 41 can be suppressed. Smoothly flows into the flame holding low speed region 100.
The other structure is the same as that of the said 1st Example and 4th Example, and the same member is shown with the same code | symbol.

In the sixth embodiment shown in FIG. 6, the pilot cone 41 is connected to an upstream cone 41a having an opening angle θ ₁ located on the upstream side and the upstream cone 41a connected to the downstream side of the upstream cone 41a. formed by the downstream cone 41b with the opening angle theta ₂ larger than the opening angle theta ₁ of the fuel injection holes 58a from the fuel passage 58 in the vicinity of the connecting portion and the upstream cone 41a and the downstream cone 41b It is configured to open.
According to the sixth embodiment, since there is no projection 60 as in the fifth embodiment, damage to the pilot cone 41 due to overheating of the projection 60 can be avoided and the flow resistance in the pilot air flow path is increased. The flame holding performance can be improved by flowing the air-fuel mixture of the pilot fuel and the pilot air injected from the fuel injection hole 58a into the pilot cone 41 into the flame holding low speed region 100.
The other structure is the same as that of the said 1st Example and 4th Example, and the same member is shown with the same code | symbol.

In the seventh embodiment shown in FIG. 7, between the main swirler 7 provided corresponding to the main nozzle 3 (see FIG. 18), a fuel passage 53 and a fuel ejection hole for ejecting fuel from the fuel passage 53 are provided. 53a is provided.
According to the seventh embodiment, since the fuel is ejected between the main swirlers 7, the fuel is ejected into the stagnation region between the swirling flows by the main swirler 7, and the stagnation region serves as a flame holding point. Flame resistance is improved. Further, since the fuel is ejected from the exit end face of the main swirler 7, flashback from the combustion zone is not caused.

In the eighth embodiment shown in FIG. 8, the fuel passage provided in the pilot cone 41 is partitioned into fuel passages 55 and 56 in a plurality of chambers along the circumferential direction of the main body inner cylinder. A fuel injection hole 57 from at least one fuel passage 55 is opened so as to inject fuel between the main swirlers 7, and the other fuel injection hole is formed in the flame holding low speed region 100 (see FIG. 1) or in the vicinity thereof. An opening is made to eject the fuel. 9 is a main cone.
According to the eighth embodiment, the fuel injection hole 57 for injecting fuel between the main swirler 7 and the fuel injection hole 51a (see FIG. 1) for injecting fuel in or near the flame holding low speed region 100 are provided in a plurality of chambers. Therefore, the distribution of the amount of fuel injected into the stagnation portion between the main swirler 7 and the amount of fuel injected into the flame holding low speed region 100 or in the vicinity thereof is distributed. It can be adjusted to the optimal distribution.

In the ninth embodiment shown in FIG. 9, the main cone burner 5 is connected to the pilot cone 41 on the outer side of the pilot nozzle 2 and is connected to the upstream passage 71b parallel to the pilot nozzle 2 and the upstream passage 71b. An air passage 71 comprising a downstream side passage 71c extending in a direction perpendicular to the side is provided, and an air ejection hole 71a of the air passage 71 is opened so as to eject air into the premixed combustion region 101 downstream of the main burner 5. doing.
According to the ninth embodiment, pilot air is injected into the premixed combustion zone 101 on the downstream side of the main burner 5, thereby diluting the premixed combustion zone 101 and suppressing the NOx generation amount. Combustion is possible. In addition, since a large circulation flow by the pilot air is formed in the low speed flame holding region 100, the flame holding property is improved.

Next, in FIG. 10 showing a tenth embodiment of the present invention, reference numeral 5 denotes a main burner, 5a denotes a burner wall of the main burner 5, and 5b denotes air passage holes formed in the burner wall 5a.
Reference numeral 41 denotes a pilot cone, which is formed in a thick portion 41b formed in the vicinity of the tip portion.
Reference numeral 72 denotes an air passage formed between the outer periphery of the thick portion 41 b and the inner periphery of the main burner 5, and the air injection hole 72 a of the air passage 72 is a premixed combustion region on the downstream side of the main burner 5. 101 is opened. 41 a is an inner peripheral surface of the pilot cone 41.
According to the tenth embodiment, by forming the thick portion 41b near the tip of the pilot cone 41, the rigidity in the vicinity of the tip of the pilot cone 41 is increased. The reduction of the passage area of the air ejection hole 72a formed between the outer periphery of the thick part 41b and the inner periphery of the main burner 5 can be prevented, and the premixed combustion zone 101 on the downstream side of the main burner 5 accompanying the reduction of the passage area. A decrease in the amount of film air and a decrease in the combustion performance of the premixed gas due to this are avoided.

In the eleventh embodiment shown in FIG. 11, an air passage 73 is formed inside the thick portion 41 b of the pilot cone 41, and the air ejection hole 73 a of the air passage 73 is premixed on the downstream side of the main burner 5. Open to the combustion zone 101. Reference numeral 5 denotes an air passage hole which is an air inlet to the air passage 73, and 74 denotes a film air forming spacer provided in the air ejection hole 73a. 5b and 5c are air passage holes formed in the burner wall 5a.
According to the eleventh embodiment, the thick portion 41b is highly rigid and the thick portion 41b is cooled by the air flowing through the air passage 73, so that the deformation of the pilot cone 41 is suppressed. Therefore, the passage area of the air ejection hole 73a of the air passage 73 formed on the inner peripheral side of the thick portion 41b can be prevented more reliably than in the tenth embodiment.
Other configurations are the same as those of the tenth embodiment, and the same members are denoted by the same reference numerals.

In the twelfth embodiment shown in FIG. 12, an air passage 73 is provided on the inner peripheral side of the pilot cone 41, and an air outlet is premixed on the inner peripheral portion of the main burner 5 on the downstream side of the main burner 5. An air passage 72 opened to the combustion zone 101 is provided via a space 77.
The air passage 73 provided on the inner peripheral side of the pilot cone 41 is bent in a U shape, and then the air ejection hole 73 b is opened inside the pilot cone 41. Reference numerals 75 and 76 denote film air forming spacers provided in the air passage 73.
According to the twelfth embodiment, the air passage 73 side provided on the inner periphery of the pilot cone 41 is easily deformed toward the inner side of the pilot cone 41. Therefore, the inner periphery of the main burner 5 is deformed by the deformation. It is possible to prevent the air ejection hole 72a of the air passage 72 provided in the portion from being blocked, and the film air can be reliably supplied from the air passage 72 to the premix combustion region 101 on the downstream side of the main burner 5.
Other configurations are the same as those of the tenth embodiment or the eleventh embodiment, and the same members are denoted by the same reference numerals.

In the thirteenth embodiment shown in FIG. 13, the air passage 73 on the inner peripheral side of the pilot cone 41 in the twelfth embodiment is opened to the premixed combustion region 101, and the air ejection hole is formed in the outer peripheral portion of the main burner 5. The air passage 78 is opened to the premixed combustion region 101 on the downstream side of the main burner 5. Reference numeral 76 denotes a film air forming spacer provided in the air passage 73.
According to the thirteenth embodiment, since the air passages 72 and 78 are provided at two locations of the inner peripheral portion and the outer peripheral portion of the main burner 5, the pilot cone 41 is deformed and the air on the inner peripheral side of the pilot cone 41 is provided. Even if the ejection of the film air from the passage 73 is blocked, the film air can be reliably supplied from the two air passages 72 and 78 to the premixed combustion region 101 on the downstream side of the main burner 5.
Other configurations are the same as those of the tenth embodiment or the twelfth embodiment, and the same members are denoted by the same reference numerals.

The fourteenth embodiment shown in FIG. 14 is a combination of the twelfth embodiment and the thirteenth embodiment. After the air passage 73 provided in the pilot cone 41 is bent into a U shape, its air ejection hole 73a is formed. Is opened to the inside of the pilot cone 41, and an air ejection hole 72 a of an air passage 72 formed in the inner periphery of the main burner 5 is opened to the premixed combustion region 101 on the downstream side of the main burner 5. An air ejection hole 78 a of the air passage 78 at the outer peripheral portion is opened to the premixed combustion region 101. Reference numeral 79 denotes a film air forming spacer provided in the air passage 72.
According to the fourteenth embodiment, film air can be supplied from the air passages 72 and 78 provided at two locations of the inner peripheral portion and the outer peripheral portion of the main burner 5 to the premixed combustion region 101 downstream of the main burner 5, Since the air passage 73 side provided on the inner peripheral side of the pilot cone 41 is easily deformed toward the inner side of the pilot cone 41, the air jet outlet of the air passage 72 in the inner peripheral portion of the main burner 5 by such deformation. It is possible to avoid blocking 72a.
Other configurations are the same as those of the twelfth embodiment or the thirteenth embodiment, and the same members are denoted by the same reference numerals.

In the fifteenth embodiment shown in FIG. 15, the air passage 72 is removed from the twelfth embodiment (FIG. 12), and the flame holding low speed region 100 is opened in the middle of the air passage 73 provided in the pilot cone 41. An escape hole 80 is provided.
According to the fourteenth embodiment, during part load operation in which the amount of deformation of the pilot cone 41 increases due to pilot combustion, part of the film air is released from the escape hole 80 to the flame holding low speed region 100, thereby It is possible to avoid the overheating of the pilot cone 41 by cooling the high temperature portion at the tip 41.
Other configurations are the same as those of the twelfth embodiment, and the same members are denoted by the same reference numerals.

In the sixteenth embodiment shown in FIG. 16, the fuel outlet of the pilot nozzle 2 is divided into a first fuel outlet 21d having a small fuel injection angle (injection angle β) and the first fuel outlet 21d. Is also provided with a second fuel outlet 21e having a large ejection angle (ejection angle α). Then, by a fuel injection port switching means (not shown), the first fuel injection port 21d having a small injection angle β is used during partial load operation below a certain load, and the injection angle α is large during high load operation exceeding the certain load. The second fuel injection port 21e is configured to be used by switching.
5 is a main burner, 5a is a burner wall of the main burner 5, and 5b and 5c are air passage holes formed in the burner wall 5a. 73 is an air passage provided on the inner peripheral side of the pilot cone 41, 73a is an air ejection hole of the air passage 73, 77 is a space portion, and 6 is a pilot swirler.

According to the sixteenth embodiment, during partial load operation where the pilot ratio (pilot combustion ratio) is large and the pilot cone 41 is at a high temperature, the pilot fuel is ejected from the first fuel ejection port 21d having a small fuel ejection angle β. At least, the pilot cone 41 should not be exposed to the pilot spray. Thus, overheating of the pilot cone 41 during operation with a large pilot ratio can be suppressed.
Further, during a high load operation where the pilot ratio is relatively small and the temperature rise of the pilot cone 41 is small, the pilot fuel is ejected from the second fuel ejection port 21e having a large fuel ejection angle α to hold the pilot fuel in flame. By supplying to the low speed region 100, good flame holding properties can be maintained.
Other configurations are the same as those of the fifteenth embodiment, and the same members are denoted by the same reference numerals.

In the seventeenth embodiment shown in FIG. 17, the pilot cone 41 is divided into an outer cone 411 provided with an air passage 73 having an air outlet 73a opened to a premixed combustion zone 101 downstream of the main burner 5. A double cone is formed with an inner cone 412 fixed to the inner periphery of the outer cone 411, and the fuel ejection direction (ejection angle α) of the fuel ejection port 21 of the pilot nozzle 2 is determined by the fuel from the fuel ejection port 21. The spray is set so that it first strikes the inner cone 412.
Other configurations are the same as those of the twelfth embodiment, and the same members are denoted by the same reference numerals.

  According to the seventeenth embodiment, the pilot flame caused by the fuel spray from the pilot nozzle 2 hits the inner cone 412 and then flows to the flame holding low speed region 100 side formed on the downstream side of the outer cone 411. This prevents the pilot flame from directly hitting the hot outer cone 411 and prevents the outer cone 411 from overheating. Further, the inner cone 412 is cooled by being exposed to the pilot air, so that it is not overheated by the direct contact with the pilot flame.

  According to the present invention, the flame holding property of the low temperature flame holding region is prevented from being lowered due to the decrease of the premixed gas concentration in the vicinity of the boundary between the premix combustion region and the low temperature flame holding region, so In addition to improving the ignition and combustion performance of the air-fuel mixture, an increase in the metal temperature in the vicinity of the flame-holding formation portion at the tip of the pilot cone is avoided, and the passage area of the air outlet at the tip of the pilot cone is reduced and premixing associated therewith It is possible to provide a gas turbine combustor in which a reduction in the combustion performance of gas is prevented.

FIG. 19 is an enlarged view of a Y part in FIG. 18 illustrating a schematic configuration in the vicinity of the flame holding low speed region and the premixed combustion region of the gas turbine combustor according to the first embodiment of the present invention. It is a figure corresponding to FIG. 1 which shows 2nd Example. (A) is a figure corresponding to Drawing 1, and (B) is a B arrow line view in (A) showing a 3rd example. It is a figure corresponding to FIG. 1 which shows 4th Example. FIG. 10 is a view corresponding to FIG. 1 illustrating a fifth embodiment. It is a figure corresponding to FIG. 1 which shows 6th Example. (A) is a W arrow view of FIG. 18, (B) is an AA arrow view in (A). It is a U arrow line view of Drawing 18 showing the 8th example. It is a figure corresponding to FIG. 1 which shows 9th Example. It is a Y section expanded sectional view of Drawing 18 showing the 10th example. FIG. 11 is a diagram corresponding to FIG. 10 illustrating an eleventh embodiment. FIG. 11 is a diagram corresponding to FIG. 10 illustrating a twelfth embodiment. FIG. 11 is a diagram corresponding to FIG. 10 illustrating a thirteenth embodiment. FIG. 11 is a diagram corresponding to FIG. 10 showing a fourteenth embodiment. FIG. 11 is a diagram corresponding to FIG. 10 illustrating a fifteenth embodiment. FIG. 11 is a diagram corresponding to FIG. 10 showing a sixteenth embodiment. FIG. 11 is a diagram corresponding to FIG. 10 showing a seventeenth embodiment. It is a schematic sectional drawing of the combustor front-end | tip part of the gas turbine combustor to which this invention is applied. It is an external view which shows schematic structure of a gas turbine combustor. It is a figure corresponding to FIG. 1 which shows the 1st example of a prior art. It is a figure corresponding to FIG. 10 which shows the 2nd example of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body cylinder 2 Pilot nozzle 3 Main nozzle 5 Main burner 6 Pilot swirler 7 Main swirler 9 Main cone 10 Air passage 10a Main air passage 11 Pilot air passage 41 Pilot cone 041 Flame holding formation part 51, 53 Fuel passage 52 Air passage 100 Flame holding Low speed range 101 Premixed combustion range

Claims (17)

  A pilot nozzle provided in the center of the cylindrical inner cylinder and a downstream tip of a plurality of main nozzles provided outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor comprising a pilot cone formed along the circumferential direction of the main body inner cylinder between the main burner, an air ejection means for ejecting air toward the downstream side of the tip end portion of the pilot cone And a fuel jetting means for jetting fuel in or near the flame holding low speed region formed on the downstream side of the tip of the pilot cone.   2. A gas turbine combustor according to claim 1, wherein air jetting means for jetting air in the flame holding low speed region or in the vicinity thereof is provided in the pilot cone on the inner peripheral side of the fuel jetting means.   The gas turbine combustor according to claim 1, wherein a plurality of fuel injection holes of the fuel injection means are formed along a circumferential direction of the main body inner cylinder.   2. The gas turbine combustion according to claim 1, wherein a fuel injection passage constituting a fuel injection means is formed partway through the pilot cone, and a fuel outlet from the fuel injection passage is opened inside the pilot cone. vessel.   5. A projecting portion projecting from the inside of the pilot cone to the pilot cone and having an interior communicating with the fuel ejection passage is formed, and the fuel ejection port is provided in the projecting portion. Gas turbine combustor.   The pilot cone is composed of an upstream cone located upstream and a downstream cone connected to the downstream of the upstream cone and having a larger opening angle than the upstream cone, and the fuel from the fuel ejection passage The gas turbine combustor according to claim 4, wherein a jet port is opened near a connection portion between the upstream cone and the downstream cone.   A pilot nozzle provided in the center of the cylindrical inner cylinder and a downstream tip of a plurality of main nozzles provided outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor comprising a pilot cone formed along the circumferential direction of the main body inner cylinder between the main burner, fuel is ejected between main swirlers provided corresponding to the main nozzles A gas turbine combustor comprising fuel injection means.   A fuel ejection passage constituting the fuel ejection means is partitioned into a plurality of chambers along the circumferential direction of the main body inner cylinder, and fuel ejection ports from at least one of the plurality of chambers are provided between the main swirlers. 8. The gas turbine combustor according to claim 7, wherein the gas turbine combustor is opened so as to inject fuel, and another fuel outlet is opened so as to inject fuel in the flame holding low speed region or in the vicinity thereof.   A pilot nozzle provided in the center of the cylindrical inner cylinder and a downstream tip of a plurality of main nozzles provided outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor comprising a pilot cone formed along a circumferential direction of the inner cylinder between the main burner, the pilot cone is disposed upstream of the pilot nozzle and in parallel with the pilot nozzle. An air jetting means comprising a side passage and a downstream passage that is connected to the upstream side passage and extends in a direction perpendicular to the main burner side, and the air jet outlet of the air jetting means is provided on the downstream side of the main burner. A gas turbine combustor, wherein the gas turbine combustor is opened to eject air into a premixed combustion zone.   A pilot nozzle provided in the center of the cylindrical inner cylinder and a downstream tip of a plurality of main nozzles provided outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor comprising a pilot cone formed along a circumferential direction of the main body inner cylinder between the main burner, the pilot cone has a thick portion formed thick, A gas turbine combustor characterized in that an air passage is formed between an outer periphery of a thick wall portion and the main burner, and an air jet port of the air passage is opened to a premixed combustion region downstream of the main burner. .   11. The gas turbine combustor according to claim 10, wherein an air passage is formed inside the thick portion, and an air outlet of the air passage is opened to a premixed combustion region downstream of the main burner.   A pilot nozzle provided in the center of the cylindrical inner cylinder and a downstream tip of a plurality of main nozzles provided outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor provided with a pilot cone formed along a circumferential direction of the main body inner cylinder between the main burner, an air passage is provided in the pilot cone, and an inner circumferential portion of the main burner is provided. A gas turbine combustor characterized in that a first air passage having an air outlet opened in a premixed combustion region downstream of the main burner is provided through a space.   The gas turbine combustor according to claim 12, wherein a second air passage having an air outlet opening in a premixed combustion region downstream of the main burner is additionally provided at an outer peripheral portion of the main burner.   An air outlet of the air passage provided in the pilot cone is opened to the inside of the pilot cone, and an air outlet is opened to a premixed combustion region downstream of the main burner at an outer peripheral portion of the main burner. The gas turbine combustor according to claim 12, further comprising an air passage.   The gas turbine combustor according to claim 12, wherein an escape hole that opens to the flame holding portion is provided in the middle of the air passage provided in the pilot cone.   A pilot nozzle provided in the center of the cylindrical inner cylinder and a downstream tip of a plurality of main nozzles provided outside the pilot nozzle along the circumferential direction of the main cylinder. In the gas turbine combustor including a pilot cone formed along a circumferential direction of the main body inner cylinder between the main burner, the pilot nozzle includes a first fuel jet outlet having a small fuel jet angle. And a second fuel injection port having a larger injection angle than the first fuel injection port, and during the partial load operation below a certain load, the first fuel injection port is operated at a high load exceeding the certain load. A gas turbine combustor characterized in that the second fuel injection port is sometimes switchable.   A pilot nozzle provided in the center of the cylindrical inner cylinder and a downstream tip of a plurality of main nozzles provided outside the pilot nozzle along the circumferential direction of the main cylinder. In a gas turbine combustor comprising a pilot cone formed along a circumferential direction of the main body inner cylinder with a main burner, the pilot cone is premixed with an air outlet downstream of the main burner. A double cone of an outer cone provided with an air passage opened in the area and an inner cone fixed to the inner periphery of the outer cone, and the fuel injection direction of the fuel outlet of the pilot nozzle A gas turbine combustor configured such that fuel jetted from an outlet first hits the inner cone.

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