JPH0875165A - Gas turbine burner - Google Patents

Abstract

PURPOSE: To uniform the concentration distribution of mixed gas near a flame holder and prevent a reverse fire phenomenon by spraying pressurized air over the outer periphery of the flame holder facing a communication passage from an air spray hole and diluting the concentration of the mixed gas near the external wall of the flame holder. CONSTITUTION: A mixed gas introduced from a preliminarily mixing gas chamber 1 is arranged to flow through a communication passage 5 offset to the axis of a combustion chamber 2 so that the mixed 985 may be introduced into the combustion chamber 2 from a ring-shaped nozzle 8 in a swirling flow. However, a pressurized air in a space 70 is sprayed from an air spray hole 17 in a tapered area of a flame holder 7 and the sprayed pressurized air is forced to flow at the combustion chamber 2 along the outer periphery of the flame holder 7 or more precisely along the tapered area. This forces the mixed gas to flow into the combustion chamber 2 from the communication passage 5 in a swirling flow while diluting the concentration of a thick concentration mixed gas prevailing near the exterior wall of the flame holder 7. It is, therefore, possible to unify the concentration of the mixed gas near the outer periphery of the flame holder 7 and prevent the generation of a back fire and restrain thermal damages of the communication passage 5 and the preliminary mixing chamber 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in gas turbine engine combustors.

[0002]

2. Description of the Related Art A combustor of a gas turbine engine (hereinafter referred to as a gas turbine) is known to have a premixing chamber in order to obtain a uniform air-fuel mixture (JP-A-60-11700).
No. 8).

Explaining this, as shown in FIGS. 7 to 9, a cylindrical combustion chamber 2 is provided on the inner periphery of the casing 4 through a heat insulating member 3, and a cylindrical mixture is supplied to the combustion chamber 2. A premix chamber 1 and a high-pressure air passage 18 for introducing pressurized air from a heat exchanger (not shown) or a compressor into the premix chamber 1 are formed.

The pressurized air flowing into the premixing chamber 1 from the high pressure air passage 18 is swirled by the swirler 15 and then mixed with the fuel injected from the main fuel injection valve 10. The premix chamber 1 is arranged substantially parallel to the cylindrical combustion chamber 2, and the premix chamber 1 communicates with the upstream of the combustion chamber 2 via a communication passage 5.

The communication passage 5 has a hole 6 at the base end of the combustion chamber 2.
It is defined by a baffle plate 6 provided with A, and at the base end of the combustion chamber 2, a cylindrical flame stabilizer 7 in which an auxiliary fuel injection valve 9 is housed is coaxial with the combustion chamber 2. In addition, the flame stabilizer 7 has the end surface 7A inserted through the hole 6A formed in the baffle plate 6 and protrudes into the combustion chamber 2 from the casing 4
Supported by the outer wall of the flame stabilizer 7 and the hole 6A of the baffle plate 6.
An annular nozzle 8 having a predetermined gap is formed between and.

The air-fuel mixture from the premix chamber 1 is introduced into the combustion chamber 2 from an annular nozzle 8 between the flame stabilizer 7 and the baffle plate 6. As shown in FIGS. 8 and 9, the communication passage 5 is arranged offset from the axis of the combustion chamber 2 along the inner circumference of the combustion chamber 2, so that the flow of the air-fuel mixture in the communication passage 5 is As shown in FIG. 8, a swirl flow is formed around the flame stabilizer 7 along the inner wall of the combustion chamber 2, and the flame in the combustion chamber 2 forms a cone-shaped flame starting from the end of the flame stabilizer 7. . In FIG. 10, the flame circulation region in the figure is the flame portion. Further, the temperature of the combustion gas is lowered by the air that has flowed in from the dilution port 12 that opens in the dilution cylinder 13 and then flows into a turbine (not shown).

[0007]

However, in such a conventional gas turbine combustor, as shown in FIGS. 8 to 10, mixing in the vicinity of the outer wall of the flame stabilizer 7 facing the annular nozzle 8 is performed. The flow velocity of the air is lower than the flow velocity of the air-fuel mixture in the central portion of the annular nozzle 8, and the concentration of the air-fuel mixture has a flame stabilizer 7
Since the outer wall and the portion along the inner periphery of the communication passage 5 are rich, the flame in the combustion chamber 2 travels near the outer wall of the flame stabilizer 7 having a high mixture concentration, and the upstream communication passage 5 and the premix chamber 1 In some cases, a flashback phenomenon that propagates to the premix chamber 1 or the communication passage 5 may be thermally damaged.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to make the concentration distribution of the air-fuel mixture in the vicinity of the flame stabilizer uniform and suppress the flashback phenomenon.

[0009]

SUMMARY OF THE INVENTION A first aspect of the present invention is a premixing device that includes a high pressure air passage for introducing pressurized air and a main fuel injection valve to mix pressurized air and fuel from the high pressure air passage. Chamber, a communication passage communicating between the combustion chamber and the premixing chamber, a flame stabilizer formed of a cylindrical member and protruding into the combustion chamber, and auxiliary fuel contained in the flame stabilizer. In a gas turbine combustor including an injection valve and an annular nozzle having the communication passage formed at a position opening to a combustion chamber and having the flame stabilizer inserted therein, an inner periphery of the flame stabilizer and an auxiliary A space formed between the outer periphery of the fuel injection valve, a pressurized air introducing means for communicating the space with a pressurized air source, and a flame stabilizer outer periphery and the space at a predetermined position facing the communication passage. And an air injection hole that communicates with.

In a second aspect based on the first aspect, the pressurized air source is a high pressure air passage.

In a third aspect based on the first aspect, the pressurized air source is an external air source.

A fourth invention is the first to third inventions.
In any one of the inventions, the air injection holes are inclined at a predetermined angle with respect to the radial direction of the flame stabilizer toward the swirling direction of the air-fuel mixture.

A fifth aspect of the present invention is the first to fourth aspects of the invention.
In any one of the inventions described above, the opening area of the air injection hole is 2.45 times or more the opening area of the end portion where the space inside the flame stabilizer opens toward the combustion chamber.

The sixth invention is the first to fifth inventions.
In any one of the inventions described above, the opening area of the air introduction hole is four times or more the opening area of the end portion where the space inside the flame stabilizer opens toward the combustion chamber.

A seventh aspect of the present invention is the first to sixth aspects of the invention.
In any one of the inventions, the air injection hole is inclined toward the combustion chamber at a predetermined angle of 0 to 75 degrees with respect to a plane orthogonal to the axis of the flame stabilizer.

[0016]

Therefore, according to the first aspect of the present invention, the space formed between the inner circumference of the flame stabilizer and the outer circumference of the auxiliary fuel injection valve is supplied from the pressurized air source via the pressurized air introducing means. Is supplied to the outer periphery of the flame stabilizer facing the communication passage from the air injection hole to dilute the concentration of the air mixture near the outer wall of the flame stabilizer to equalize the concentration of the air mixture. Therefore, it is possible to prevent a flashback phenomenon due to a high concentration of air-fuel mixture.

Further, in the second aspect of the invention, since the pressurized air source is the high pressure air passage, the pressurized air can be guided to the space inside the flame stabilizer with a simple structure.

Further, in the third invention, since the pressurized air source is an external air source, any pressurized air can be introduced into the space inside the flame stabilizer, and the heating depending on the operating state of the gas turbine can be performed. Compressed air can be supplied.

Further, in the fourth aspect of the invention, since the pressurized air from the air injection hole is jetted in the swirling direction of the air-fuel mixture, the air-fuel mixture near the outer wall of the flame stabilizer is swirled to increase the flow velocity. It can be increased and the flame in the combustion chamber can be stabilized.

Further, in the fifth aspect of the invention, the opening area of the air injection hole is 2.45 times or more the opening area of the end portion where the space inside the flame stabilizer opens facing the combustion chamber. The flow rate of the pressurized air injected from the air injection hole to the outer circumference of the flame stabilizer can be made higher than the flow rate of the pressurized air leaking into the combustion chamber from the gap between the flame stabilizer and the auxiliary fuel injection valve, and the mixture is diluted. It is possible to secure a flow rate for

In the sixth aspect of the invention, since the opening area of the air introduction hole is four times or more of the opening area of the end of the space inside the flame stabilizer facing the combustion chamber, the air injection is performed. It is possible to secure the flow rate required for injection from the holes and the gap between the flame stabilizer and the auxiliary fuel injection valve.

Further, in the seventh invention, since the air injection hole is inclined toward the combustion chamber at a predetermined angle between 0 and 75 degrees with respect to a plane orthogonal to the axis of the flame stabilizer, It is possible to suppress the pressurized air from peeling from the outer circumference of the flame stabilizer, and it is possible to reliably reduce the concentration of the air-fuel mixture near the outer wall of the flame stabilizer.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a cylindrical combustion chamber 2 is provided on the inner circumference of a casing 4 via a heat insulating member 3, and a cylindrical premixing chamber 1 and a premixing chamber 1 for supplying a mixture to the combustion chamber 2. High pressure air passages 18 for introducing pressurized air from a heat exchanger (not shown) or the like are formed therein.

The premixing chamber 1 is a swirler 1 arranged on the upstream side.
5, the main fuel injection valve 10 is provided inside, and the downstream side of the premixing chamber 1 communicates with the combustion chamber 2 via the communication passage 5.

The communication passage 5 is offset from the axis of the combustion chamber 2 in order to impart a swirl to the air-fuel mixture along the inner circumference of the combustion chamber 2 in the same manner as in FIG. 8 shown in the above-mentioned conventional example. The communication passage 5 is defined by the baffle plate 6 at the base end of the combustion chamber 2, and the communication passage 5 is provided through a hole 6A formed through the baffle plate 6 coaxially with the combustion chamber 2. Communicate with the combustion chamber 2.

A cylindrical flame stabilizer 7 accommodating a cylindrical auxiliary fuel injection valve 9 from the base end of the combustion chamber 2 to the inside is provided coaxially with the combustion chamber 2 so as to project therefrom. Is supported by the casing 4 such that the end surface 7A is inserted into the hole 6A of the baffle plate 6 and protrudes into the combustion chamber 2 by a predetermined amount, and the outer wall of the flame stabilizer 7 and the inner periphery of the hole 6A of the baffle plate 6 are An annular nozzle 8 having a predetermined gap is formed between and.

An ignition pin 11 is arranged at a predetermined position facing the combustion chamber 2, and a dilution cylinder 13 having a plurality of dilution ports 12 is fitted on the downstream side of the combustion chamber 2 and the combustion chamber is The combustion gas from 2 is introduced into the turbine (not shown) after the combustion gas temperature is lowered by the air flowing in from the dilution port 12 of the dilution cylinder 13.

On the other hand, a high pressure air passage 18 for introducing pressurized air from a heat exchanger or the like (not shown) is extended to the base end of the combustion chamber 2 and is different from the communication passage 5 arranged at the base end of the combustion chamber 2. Partition wall 5
Defined through 0.

A flame stabilizer 7 disposed on the base end side of the combustion chamber 2.
From the casing 4 side, sequentially penetrating through the high pressure air passage 18 and the communication passage 5 and projecting into the combustion chamber 2.
A cylindrical space 70 is formed in the inside of the cylinder with a predetermined gap between the inner circumference of the flame stabilizer 7 and the outer circumference of the auxiliary fuel injection valve 9,
This space 70 is the end surface 7A of the flame stabilizer 7 protruding into the combustion chamber 2.
On the side, the combustion chamber 2 is opened through a gap CL between the outer periphery of the end of the auxiliary fuel injection valve 9 and the inner periphery of the flame stabilizer 7.

On the casing 4 side of the flame stabilizer 7 facing the high pressure air passage 18, a plurality of air introduction holes 16 are formed as pressurized air introduction means for communicating the outer periphery with the internal space 70, while the combustion chamber is formed. In the flame stabilizer 7 on the second side, the outer wall of the flame stabilizer 7 and the space 70, that is, the inner circumference of the flame stabilizer 7 at a predetermined position facing the communication passage 5 on the casing 4 side from the end surface 7A by a predetermined distance L. A plurality of air injection holes 17 that communicate with each other are formed.

Here, as shown in FIGS. 2 and 3, the air injection holes 17 are formed so as to extend radially along the radial direction of the flame stabilizer 7, and the air injection holes 17 open to the outer periphery of the flame stabilizer 7. The position L is set to a predetermined position facing the communication passage 5 from the position facing the annular nozzle 8, and the air injection hole 17 is angled α to the combustion chamber 2 side with respect to the plane orthogonal to the axis of the flame stabilizer 7. And the outer periphery of the flame stabilizer 7 is formed with a taper portion 7B having an angle β that enlarges the outer diameter from the position where the air injection hole 17 is opened toward the end surface 7A.

This angle β is 0 to 90 degrees, preferably 5 to
It is set to a predetermined value between 80 degrees. In addition, this flame stabilizer 7
The tapered portion 7B constitutes the inner peripheral side of the annular nozzle 8.

The predetermined angle α of the air injection hole 17 toward the combustion chamber 2 is set to a predetermined value between 0 and 75 degrees according to the angle β of the taper portion 7B. This is to prevent the injected pressurized air from peeling off from the surface of the tapered portion 7B.

The total opening area of these air injection holes 17 is S _A
As shown in FIG. 2, the cross-sectional area of the gap CL between the outer periphery of the end of the auxiliary fuel injection valve 9 and the inner periphery of the end of the flame stabilizer 7 where the space 70 opens on the side of the combustion chamber 2 is the opening area of the space 70. If S _CL , the total opening area S _A of the air injection holes 17 is set to 2.45 times or more of the opening area S _CL of the space 70.

Further, assuming that the total opening area of the air introduction holes 16 communicating with the high pressure air passage 18 is S _B , the air introduction holes 1
The total opening area S _B of 6 is set to 4 times or more of the opening area S _CL of the space 70.

With the above construction, the operation will be described.

A part of the pressurized air from the heat exchanger (not shown) is introduced from the high pressure air passage 18 through the swirler 15 into the premixing chamber 1, where it is mixed with the fuel injected from the main fuel injection valve 10. As a result, the air-fuel mixture becomes a swirl flow centered on the flame stabilizer 7 by being guided through the communication passage 5, and the annular nozzle 8 between the hole 6A of the baffle plate 6 and the flame stabilizer 7 transfers to the combustion chamber 2. It is introduced while turning.

The air-fuel mixture thus introduced into the combustion chamber 2 burns in the combustion chamber 2 while being further mixed with the fuel selectively injected from the auxiliary fuel injection valve 9, and flows in from the dilution port 12 opened in the dilution cylinder 13. After lowering the combustion gas temperature with this air, it flows into a turbine (not shown) to drive the compressor and load.

On the other hand, part of the pressurized air in the high-pressure air passage 18 is introduced to the base end side of the combustion chamber 2 and is introduced into the space 70 inside the flame stabilizer 7 through the air introduction hole 16.

A part of the pressurized air flowing into the space 70 is radially from the air injection hole 17 in the radial direction of the flame stabilizer 7, and is directed to the combustion chamber 2 in accordance with the angle α of the air injection hole 17. The other pressurized air flows into the combustion chamber 2 through the gap CL between the flame stabilizer 7 and the auxiliary fuel injection valve 9.

The air-fuel mixture introduced from the premix chamber 1 is the combustion chamber 2
When passing through the communication passage 5 offset with respect to the axis, a swirl flow is introduced from the annular nozzle 8 to the combustion chamber 2, but at the taper portion 7B of the flame stabilizer 7, the air injection hole 17
The pressurized air in the space 70 is jetted from the space 70, and the jetted pressurized air travels to the combustion chamber 2 along the outer periphery of the flame stabilizer 7, that is, along the tapered portion 7B. As shown in the example, the air-fuel mixture in the vicinity of the outer wall of the flame stabilizer 7 having a high air-fuel mixture concentration is diluted toward the combustion chamber 2, and as shown in FIG. As a result, it is possible to prevent the flashback as in the conventional example, and to suppress the thermal damage to the communication passage 5 and the premix chamber 1.

Here, the air-fuel mixture introduced from the communication passage 5 into the combustion chamber 2 has a swirler 15 passing therethrough when flowing into the premixing chamber 1 and a pressure loss when flowing into the communication passage 5 from the premixing chamber 1. Therefore, the relationship between the pressures of the respective parts is the high-pressure air passage 18> the space 70> the communication passage 5> the combustion chamber 2, the pressure difference between the high-pressure air passage 18 and the communication passage 5 is 5 to 10 KPa, and the pressure between the communication passage 5 and the combustion chamber 2 is The difference is estimated to be about 5 KPa, and the high pressure air passage 1
The pressurized air flowing from 8 to the space 70 flows from the communication passage 5 to the combustion chamber 2 without backflow due to the pressure difference as described above.

Since the pressurized air in the space 70 flows into the combustion chamber 2 not only from the air injection hole 17 but also from the gap CL between the auxiliary fuel injection valve 9 on the end face 7A side of the flame stabilizer 7, the air injection hole 17
The pressurized air injected along the taper portion 7B of the flame stabilizer 7 is set to be equal to or higher than the flow rate of the pressurized air leaking from the space 70 to the combustion chamber 2 through the gap CL and introduced from the high pressure air passage 18. It is necessary to efficiently guide the compressed air to the vicinity of the outer circumference of the flame stabilizer 7 to smoothly dilute the mixture concentration.

Assuming that the air injection hole 17 is an orifice and the pressure difference between the front and rear of the air injection hole 17, that is, the pressure difference between the space 70 and the outer periphery of the flame stabilizer 7 is ΔP, the air injection hole 1
The flow rate Q of the fluid passing through 7 is in the relationship of Q∝S _A × ΔP ^1/2 , and the pressure difference ΔP between the space 70 inside the flame stabilizer 7 and the combustion chamber 2 is ΔP.
_{When CL} is set to 7 to 8 KPa, the space 70 and the communication passage 5
And the pressure difference ΔP is 2 to 3 KPa. Here, the total opening area of the air injection holes 17 is set so that the flow rate Q of the pressurized air injected from the air injection holes 17 is set to be equal to or more than the flow rate of the pressurized air leaking from the space 70 to the combustion chamber 2 through the gap CL. S _{A is set} to 2.45 times or more of the area S _CL where the space 70 opens into the combustion chamber 2.

On the other hand, in order to supply the necessary and sufficient pressurized air from the high pressure air passage 18 to the air injection hole 17 and the gap CL between the flame stabilizer 7 and the auxiliary fuel injection valve 9 through the air introduction hole 16. The total opening area S _A of the air injection hole 17 and the space 70
From the relationship with the opening area S _CL of the above, the flow rate of the pressurized air flowing from the air introduction hole 16 is not less than twice that of the pressurized air passing through the gap CL. The area S _B is set to 4 times or more of the opening area S _CL of the space 70, and the pressurized air required to be injected from the air injection hole 17 to dilute the air-fuel mixture can be supplied to the space 70.

In this way, the air-fuel mixture from the communication passage 5 flowing into the combustion chamber 2 while swirling from the annular nozzle 8 is added from the air injection hole 17 facing the communication passage 5 and opening to the flame stabilizer 7. The compressed air dilutes the air-fuel mixture concentration in the vicinity of the outer wall of the flame stabilizer 7, and the air-fuel mixture concentration can be made substantially uniform, so that the flashback as in the conventional example can be prevented. Thus, the thermal damage to the communication passage 5 and the premix chamber 1 can be suppressed.

Further, the total opening area S _A of the air injection holes 17
Is more than 2.45 times the area S _CL where the space 70 opens into the combustion chamber 2, and the total opening area S _B of the air introduction holes 16 is
_Is set to be four times or more of the opening area S _CL of the space 70,
Pressurized air can smoothly flow from the high-pressure air passage 18 to the air injection hole 17 and the gap CL between the flame stabilizer 7 and the auxiliary fuel injection valve 9 through the air introduction hole 16, while diluting the air-fuel mixture. Therefore, the flow rate of the pressurized air injected from the air injection hole 17 can be secured.

FIG. 5 shows a second embodiment, in which the air injection holes 17 radially arranged in the radial direction of the flame stabilizer 7 in the first embodiment are directed in the swirling direction of the air-fuel mixture in the communication passage 5. And is tilted at a predetermined angle θ with respect to the radial direction of the flame stabilizer 7, and other configurations are similar to those of the first embodiment.

By providing the air injection hole 17 with the inclination of the angle θ, it is possible to swirl the air-fuel mixture in the vicinity of the outer wall of the flame stabilizer 7, so that the flame in the combustion chamber 2 is different from the conventional example. While improving the stability, it is possible to prevent the flashback by homogenizing the air-fuel mixture concentration in the vicinity of the outer circumference of the flame stabilizer 7 in the same manner as described above.

FIG. 6 shows a third embodiment, in which the air introduction hole 16 in the first embodiment is eliminated and the space 70 of the flame stabilizer 7 is pressurized outside the combustor via the air introduction pipe 21. It communicates with the air source 19 and the control unit 20, and other configurations are similar to those of the first embodiment.

The control unit 20 controls the flow rate, pressure and temperature of the pressurized air sent from the pressurized air source 19 arranged outside the combustor to predetermined values, and then enters the space 70 of the flame stabilizer 7. In the same manner as above, the backfire is prevented by the pressurized air injected from the air injection hole 17, and the control unit 20 changes the pressurized air injected to prevent the backfire to the operating state of the gas turbine. Accordingly, it is possible to change the flow rate, pressure, and temperature, respectively, and it is possible to prevent flashback more finely.

[0053]

As described above, according to the first aspect of the present invention, the high pressure air passage for introducing the pressurized air and the main fuel injection valve are provided, and the compressed air from the high pressure air passage is mixed with the fuel. A mixing chamber, a communication passage that connects the combustion chamber and the premixing chamber, a flame stabilizer formed of a tubular member and protruding into the combustion chamber, and an auxiliary device housed inside the flame stabilizer. In a combustor of a gas turbine provided with a fuel injection valve and an annular nozzle formed at a position where the communication passage opens into a combustion chamber and having the flame stabilizer inserted therein, an inner circumference of the flame stabilizer is provided. A space formed between the auxiliary fuel injection valve and the outer periphery of the auxiliary fuel injection valve, and pressurized air introduction means for communicating the space with a pressurized air source,
An air injection hole that communicates the outer circumference of the flame stabilizer and the space at a predetermined position facing the communication passage, and injects pressurized air from the air injection hole to the outer circumference of the flame stabilizer facing the communication passage, By diluting the concentration of the air-fuel mixture near the outer wall of the flame stabilizer, the concentration of the air-fuel mixture can be made uniform, and it is possible to prevent flashback due to the high-concentration air-fuel mixture as in the conventional example. It is possible to suppress thermal damage to the communication passage or the premixing chamber and improve reliability.

In the second aspect of the invention, since the pressurized air source is the high pressure air passage, the pressurized air can be guided to the inner space of the flame stabilizer with a simple structure, which suppresses an increase in manufacturing cost. While preventing flashback.

Further, in the third invention, since the pressurized air source is the external air source, it is possible to supply any pressurized air according to the operating state of the gas turbine, and to prevent the flashback while burning. Can be controlled.

According to a fourth aspect of the invention, the air injection holes are inclined at a predetermined angle with respect to the radial direction of the flame stabilizer toward the swirling direction of the air-fuel mixture, and the pressurized air from the air injection holes is mixed. The air is injected in the swirling direction, swirling is imparted to the air-fuel mixture in the vicinity of the outer wall of the flame stabilizer, and the flame in the combustion chamber can be stabilized, so that the reliability can be improved.

Further, in the fifth aspect of the invention, since the opening area of the air injection hole is 2.45 times or more the opening area of the end portion where the space inside the flame stabilizer opens toward the combustion chamber, It is possible to secure the flow rate of the pressurized air injected from the air injection hole for diluting the air to the outer circumference of the flame stabilizer to reliably prevent the flashback.

According to the sixth aspect of the invention, since the opening area of the air introduction hole is four times or more of the opening area of the end portion where the space inside the flame stabilizer opens toward the combustion chamber, the mixture is It is possible to ensure pressurized air for dilution and reliably prevent flashback.

Further, in the seventh invention, since the air injection hole is inclined toward the combustion chamber at a predetermined angle between 0 and 75 degrees with respect to the plane orthogonal to the axis of the flame stabilizer, Since the pressurized air of the heading is directed to the combustion chamber along the outer circumference of the flame stabilizer without being separated from the outer wall of the flame stabilizer, the concentration of the air-fuel mixture near the outer wall of the flame stabilizer can be reliably reduced, and a flashback occurs. Can be reliably suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view of a combustor showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the flame stabilizer.

FIG. 3 is a sectional view taken on line AA of FIG. 2;

FIG. 4 is a diagram showing a concentration distribution of an air-fuel mixture from a communication passage to a combustion chamber.

FIG. 5 is a sectional view of a flame stabilizer showing a second embodiment.

FIG. 6 is a sectional view of a combustor showing a third embodiment.

FIG. 7 is a cross-sectional view of a combustor showing a conventional example.

8 is a diagram showing a concentration distribution of an air-fuel mixture in a cross section taken along the line BB in FIG.

9 is a diagram showing a flow velocity distribution of the air-fuel mixture in a cross section taken along the line BB of FIG.

FIG. 10 is a diagram showing the concentration distribution of the air-fuel mixture from the communication passage to the combustion chamber.

[Explanation of symbols]

 1 Premixing chamber 2 Combustion chamber 5 Communication passage 7 Flame stabilizer 8 Annular nozzle 9 Auxiliary fuel injection valve 10 Main fuel injection valve 16 Air introduction hole 17 Air injection hole 18 High pressure air passage 19 Pressurized air source 21 Air introduction pipe 70 Space

Claims (7)

[Claims] 1. A high pressure air passage for introducing pressurized air, a premixing chamber having a main fuel injection valve for mixing pressurized air and fuel from the high pressure air passage, a combustion chamber and a premixing chamber. A communication passage, a flame stabilizer formed of a tubular member and protruding into the combustion chamber, an auxiliary fuel injection valve accommodated in the flame stabilizer, and the communication passage In a combustor of a gas turbine, which is formed at a position open to the inside and has an annular nozzle through which the flame stabilizer is inserted, the combustor is formed between the inner circumference of the flame stabilizer and the outer circumference of the auxiliary fuel injection valve. A compressed space, a pressurized air introducing means for communicating the space with a pressurized air source, and an air injection hole for communicating the outer periphery of the flame stabilizer with the space at a predetermined position facing the communication passage. Combustor of gas turbine characterized by 2. The combustor of a gas turbine according to claim 1, wherein the pressurized air source is a high pressure air passage. 3. The combustor of a gas turbine according to claim 1, wherein the pressurized air source is an external air source. 4. The air injection hole is inclined at a predetermined angle with respect to the radial direction of the flame stabilizer toward the swirling direction of the air-fuel mixture, according to any one of claims 1 to 3. A combustor of the described gas turbine. 5. The opening area of the air injection hole is 2.45 times or more the opening area of the end of the space inside the flame stabilizer facing the combustion chamber. A combustor for a gas turbine according to any one of claims 1 to 4. 6. The opening area of the air introduction hole is four times or more of the opening area of the end of the space inside the flame stabilizer facing the combustion chamber. A combustor for a gas turbine according to claim 5. 7. The air injection hole is inclined toward the combustion chamber at a predetermined angle between 0 and 75 degrees with respect to a plane orthogonal to the axis of the flame stabilizer. A combustor for a gas turbine according to any one of 6.