JP3371467B2 - Gas turbine combustor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine combustor suitable as a combustor for an aeronautical gas turbine, for example.

[0002]

2. Description of the Related Art In recent years, a high performance gas turbine engine has been developed, and a combustor provided in the latter stage of a compressor is not only small and lightweight and has high combustion efficiency, but also from the ground to high altitude. Various researches and developments have been conducted to obtain good ignition and stable combustion under all engine use conditions, and to make exhaust pollution such as NOx (nitrogen oxide) close to insignificant.

[0003]

As a conventional technique for the NOX countermeasure of the combustor, firstly, a lean fuel is prepared by increasing the amount of compressed air sent to the combustor and mixing it with the fuel. It is known that NOx is reduced by burning the in the combustion cylinder to lower the flame temperature in the combustion cylinder. Secondly, it is known that NOx is reduced by shortening the residence time of the combustion gas inside the combustion cylinder.

However, the constant use of a lean fuel, which is good in terms of NOX countermeasures, is problematic in other respects. That is, there is a possibility that good ignition and stable combustion of the combustor may not be obtained when the engine is ignited on the ground or when the engine is idling.

On the other hand, the development of a combustor includes reduction in size and weight as described above, but it is important to design the combustor to have a short length in the direction of the central axis of the engine because it directly affects the overall length of the engine. It becomes a development factor. However, if a lean burner with a short length is used to burn a lean fuel that is good in terms of NOx, a sufficient burning time in the combustion cylinder cannot be obtained, and the burning efficiency is reduced.

The present invention has been made in view of the above circumstances, and provides a gas turbine combustor capable of simultaneously reducing NOx (nitrogen oxide) and shortening the length of the combustor. The purpose is to

[0007]

A gas turbine combustor according to the present invention includes a fuel nozzle section for mixing compressed air sent from a compressor with fuel and for igniting fuel, and a fuel nozzle section and a combustion chamber partition wall. A gas turbine combustor having a combustion cylinder of an integral annular structure which is continuously arranged on the rear stage side and burns the supplied fuel, wherein the fuel nozzle section has a periphery of a central portion of a combustion chamber partition wall having an annular outlet. A plurality of pilot combustion parts arranged on a concentric circle across the direction, and arranged on a concentric circle of a diameter larger and smaller than the pitch circle of the pilot combustion part, and its outlet is the outlet of the pilot combustion part of the combustion chamber partition wall. It is composed of a plurality of lean fuel supply parts arranged so as to be located in the vicinity and an ignition plug for igniting the fuel in the pilot combustion part. It is composed of a fuel injection valve and a pilot flame holding cylinder connected to the tip of the fuel injection valve, and has a structure in which the flame extends from the pilot flame holding cylinder to the inside of the combustion cylinder. A main fuel injection valve that supplies a lean fuel to the combustion cylinder with a large amount of mixing, and a premix pre-evaporator that is connected to the tip of the main fuel injection valve to promote mixing of fuel with compressed air and fuel evaporation. It is composed of a pipe and a main fuel injection valve
Flow atomization fuel injection that atomizes fuel by air flow
It is composed of a valve, and the tip of the air atomization fuel injection valve
To swirl the supply air flow into the premix pre-evaporation tube
An air swirler is installed and the air flow atomization type combustion
Direction of air flow of fuel injection valve and air flow from air swirler
Is reversely set .

[0008]

[0009]

Further, a conical throttle for accelerating the air flow to the combustion tube is provided at the outlet of the premixing / pre-evaporating pipe, and further, a member for fixing the throttle is provided for giving swirl to the flow of the air-fuel mixture. A swirl vane structure is desirable.

As the compressed air sent from the compressor, it is desirable to supply all the air other than the cooling air sent to the combustion cylinder to the lean fuel supply section of the fuel nozzle section.

[0012]

According to the gas turbine combustor of the present invention , in the low output state from ignition to idle by the spark plug,
A combustion chamber inside the pilot flame holding cylinder of the pilot combustion section,
Since the combustion region of the combustion cylinder is long with the combustion chamber, high combustion efficiency is obtained, and good ignition performance and stable combustion that does not blow out are achieved. Further, at the time of high output, when the lean fuel whose mixing property with the compressed air is enhanced by the premixing pre-evaporation pipe of the lean fuel supply section flows into the inside of the combustion cylinder, the combustion region has a length only inside the combustion cylinder. Therefore, the combustion residence time can be shortened, which results in NOx in the exhaust gas.
Is reduced.

Further, according to the gas turbine combustor of the present invention, the swirling air flow from the main fuel injection valve reliably atomizes the fuel and enhances the mixing property with the compressed air.

Further, according to the gas turbine combustor of the present invention , it is possible to shorten the premixing pre-evaporation pipe,
Moreover, autoignition does not occur in the premixing pre-evaporation pipe, and air does not flow backward or stagnant in the premixing pre-evaporation pipe.

Further, according to the gas turbine combustor of the present invention , flashback is prevented from the combustion chamber side to the premix pre-evaporation pipe, and the flow of the air-fuel mixture at the outlet of the pre-mix pre-evaporation pipe is widened. As a result, a circulating flow is generated in the combustion chamber behind the throttle of the outlet of the premixing pre-evaporation pipe, the flame in the combustion chamber stabilizes, and the circulating flow interferes with the pilot combustion section, causing the fire transfer from the pilot combustion section. Will be good.

According to the gas turbine combustor of the present invention , reduction of NOx in exhaust gas can be further promoted.
Further, the combustor outlet temperature distribution can be made uniform without providing air holes in the combustor liner.

Therefore, in the gas turbine combustor of the present invention, the entire area of the inside of the combustion cylinder is effectively used as a combustion region from ignition to high output, so that the length of the combustor can be shortened. At the same time, NOX can be reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the gas turbine combustor of the present invention will be described below with reference to FIGS. A gas turbine combustor 1 according to the present invention includes a combustion cylinder 3 having an integral annular structure, which is arranged in a subsequent stage of a compressor side (a position indicated by reference numeral 2 in the drawing).
And a fuel nozzle portion 4 for mixing the compressed air sent from the compressor side 2 with the fuel and for igniting the fuel.

In the combustion cylinder 3, an outer liner 7 and an inner liner 8 are arranged in a circumferential direction around the axis of the engine body to form a combustion peripheral wall, and a combustion chamber partition wall 9 is formed between the combustion peripheral walls. The inside of them is a combustion chamber 10. Then, a part of the compressed air flowing from the compressor side 2 passes through the inner walls of the outer liner 7 and the inner liner 8 to form an air layer on the inner walls thereof, thereby cooling the entire combustion peripheral wall at the time of combustion. Is being done.

The combustion chamber partition wall 9 comprises a plurality of pilot combustion parts 11, ..., Lean fuel supply parts 15, ... And a spark plug 23 arranged toward the flame holding cylinder 13 of a predetermined pilot combustion part 11. The fuel nozzle section 4 is provided.

As shown in FIG. 2, the plurality of pilot combustion sections 11 are arranged at predetermined intervals in the circumferential direction of a predetermined radius R2 from the axis of the engine body. As shown in FIG. 1, these pilot combustion sections 11 have a structure in which a flame holding cylinder 13 is connected to the tip of a pilot fuel injection valve 12, and the tip of the flame holding cylinder 13 is fixed to the combustion chamber partition wall 9. ing. Then, in each pilot combustion unit 11, the fuel supplied from the fuel supply unit 14 is supplied to the pilot fuel injection valve 12
While spraying the fuel into the pilot combustion chamber in the flame holding cylinder 13 from the plurality of air holes 13a formed in the flame holding cylinder 13, a predetermined amount of air flows into the pilot combustion chamber to mix with the fuel. As shown in FIG. 2, the fuel is ignited by the ignition plug 23 arranged toward the predetermined flame holding cylinder 13, so that the combustion is performed in the pilot combustion chamber. As a result, the fuel that has not been made into a lean state burns, so that good ignitability and stable combustion that does not blow out easily can be obtained.

On the other hand, as shown in FIG. 2, the lean fuel supply section 15 ... Arranges in rows in the circumferential direction in which the radius from the axis of the engine body is larger than the disposition position of the pilot combustion section 11 ... (R3). Further, they are arranged in a row in the circumferential direction having a radius smaller than that of the pilot combustion parts 11 ... (R1). As shown in FIG. 1, the lean fuel supply unit 15 includes a main fuel injection valve 16 and a premixing pre-evaporation pipe 17 continuously provided at the tip of the main fuel injection valve 16.
And an air swirler 18 arranged around the tip of the main fuel injection valve 16.

The premixing preevaporation pipe 17 is a short tubular member, and is outside the pipe (for example, heat of air supplied from the compressor 2).
The fuel in the tube is heated and evaporated by the amount of heat obtained from
It is used as a gaseous fuel. As a result, the particle size of the fuel becomes small, the mixing property of the compressed air and the fuel becomes good, and N
It is possible to prevent the generation of OX.

As a concrete structure of the main fuel injection valve 16, an air flow atomization type fuel injection valve is used,
Fuel is supplied from the fuel supply unit 14 to the fuel passage indicated by reference numeral 19 to spray the film fuel into the premixing pre-evaporation pipe 17, while the axial air passage 20 and the air passage provided on the outer peripheral side are provided. The compressed air that has passed through 21 is swirling mixed in a predetermined direction with the inside and outside of the film-shaped fuel being sandwiched, and is ejected into the premixing preevaporation pipe 17. By using this air stream atomizing fuel injection valve 16, the fuel is surely atomized by the swirling air flow, and the mixing property with the compressed air sent from the air swirler 18 is improved. Further, the fuel is in a lean state (equivalent ratio of the amount of air to the amount of fuel is 0.3 to
About 0.8).

Further, the air swirler 18 provided at the tip of the air flow atomization type fuel injection valve 16 enhances the mixing property with the compressed air flowing into the premixing / pre-evaporating pipe 17 and the air flow atomization type. The compressed air is swirled in a direction opposite to the swirling direction of the fuel sprayed from the fuel injection valve 16. As described above, the swirling directions of the fuel sprayed from the airflow atomizing fuel injection valve 16 and the compressed air from the air swirler 18 are opposite to each other, so that swirling components of the mutual air flows cancel each other out and premixing is performed. The stagnation of the flow disappears in the pre-evaporation pipe 17, and self-ignition does not occur in the pre-mixing pre-evaporation pipe 17.

Since the mixing property of the compressed air and the fuel is enhanced by the air stream atomizing fuel injection valve 16 and the air swirler 18, even if the premixing pre-evaporating pipe 17 is designed in a short length, it is sufficiently compressed. The mixing property of air and fuel can be improved.

Here, the combustion chamber 10 of the premixing pre-evaporation pipe 17
A conical throttle 22 having its apex facing the inside of the premixing pre-evaporation pipe 17 is provided at the outlet 17a facing the pre-mixing pre-evaporation pipe 17 by the swirl vanes 22a.
It is fixed to.

Since the throttle 22 is provided, the air-fuel mixture inside the premixing pre-evaporation pipe 17 is accelerated and flows out to the combustion chamber 10 side, and the reverse flow from the combustion chamber 10 side to the premixing pre-evaporation pipe 17 is performed. Fire protection is provided. Further, the throttle 22 has a conical shape, and the swirl vanes 22 a are arranged around the conical shape, so that the air-fuel mixture is discharged from the outlet 17 of the pre-mix pre-evaporation pipe 17.
The flow spreads at a, and a circulating flow is generated at the center of the outlet 17a to stabilize the flame in the combustion chamber 10. At the same time, the pilot combustion unit 11 and this circulating flow interfere with each other to prevent the fire transfer from the pilot combustion unit 11. It tends to be good.

Therefore, the gas turbine combustor 1 of this embodiment can obtain the following excellent effects. Pilot combustion sections 11 ... With good ignition and flame holding properties are provided in a row in the circumferential direction centering on the axis of the engine body. The lean fuel supply section 15 having a premixing pre-evaporation pipe 17 having a good mixing property with air is provided in a row, and is designed so that the entire combustion chamber 10 becomes a combustion region. Therefore, reduction of NOx and reduction of the length of the combustor can be achieved at the same time. The lean fuel supply unit 15 includes an air flow atomization type fuel injection valve 16
Is used, the fuel is surely atomized by the swirling air flow and the mixing property with the compressed air is enhanced. Since the air swirler 18 is provided at the tip portion of the air stream atomization type fuel injection valve 16, the premixing pre-evaporation pipe 17 can be shortened and the air flow atomization type fuel injection valve 16 sprays. By making the swirling directions of the fuel to be generated and the compressed air from the air swirler 18 opposite to each other, autoignition does not occur in the premixing pre-evaporation pipe 17 and the premixing pre-evaporation pipe 17
There is no backflow or stagnation of air inside. By providing the throttle 22 at the outlet 17a of the premixing pre-evaporation pipe 17, the fuel air inside the premixing pre-evaporation pipe 17 is accelerated and flows out to the combustion chamber 10 side, and the fuel air from the combustion chamber 10 side is pre-heated. Flashback to the mixing pre-evaporation pipe 17 is prevented. Further, since the rotating throttle fixing member 23 is provided, the flow of the fuel air at the outlet 17a of the premixing pre-evaporating pipe 17 spreads, and a backflow occurs in the central portion of the adjacent outlets 17a, 17a, so that the inside of the combustion chamber 10 The flame is stabilized, and the flame transfer from the pilot combustion section 11 becomes good.

Next, the operation mode of the gas turbine engine employing the gas turbine combustor having the above-described structure at the time of low output or high output will be described together with the operation. At low output from ignition to idle, combustion operation is performed by fuel supply from the fuel supply unit 14 to each pilot combustion unit 11. As a result, the combustion chamber of the flame holding cylinder 12 of the pilot combustion unit 11 and the combustion chamber 10 form a combustion region, and a long combustion region is obtained, so that high combustion efficiency can be obtained, and the pilot combustion unit 11 is in a lean state. Since the unburned fuel burns, the ignitability is good, and the stable burning does not easily blow out.

On the other hand, at the time of high output, the fuel is supplied from the fuel supply unit 14 to the pilot combustion unit 11 as well as to the lean fuel supply unit 15. Lean fuel supply unit 15
The fuel of ... Is sufficiently mixed with the compressed air by the action of the air flow atomization type fuel injection valve 16, the air swirler 18, and the premixing / pre-evaporating pipe 17 together with the introduction of a large amount of compressed air, so that the lean fuel is diluted. Becomes And this lean fuel is used in the combustion chamber 1.
When it flows into 0, the combustion area is only the length of the combustion chamber 10, so that the residence time can be shortened. As a result, in the gas turbine combustor of the present embodiment, as is clear from the NOx amount shown between the black circles (●) in FIG.
The amount of OX can be significantly reduced.

[0032]

As described above, in the gas turbine combustor of the present invention , in the low output state from ignition to idle, the combustion chamber inside the pilot flame holding cylinder of the pilot combustion section and the combustion chamber of the combustion cylinder. Therefore, high combustion efficiency can be obtained, and ignitability is good and stable combustion does not blow out. Further, at the time of high output, when the lean fuel whose mixing property with the compressed air is enhanced by the premixing pre-evaporation pipe of the lean fuel supply section flows into the inside of the combustion cylinder, the combustion region has a length only inside the combustion cylinder. Therefore, the combustion residence time can be shortened, and thereby nitrogen oxides in the exhaust gas can be reduced.

Further, according to the gas turbine combustor of the present invention, the swirling air flow from the main fuel injection valve can surely atomize the fuel and enhance the mixing property with the compressed air.

Further, according to the gas turbine combustor of the present invention , it is possible to shorten the premixing pre-evaporation pipe,
Moreover, autoignition does not occur in the premixing pre-evaporation pipe, and air does not flow backward or stagnant in the premixing pre-evaporation pipe.

Further, according to the gas turbine combustor of the present invention , flashback is prevented from the combustion chamber side to the premix pre-evaporation pipe, and the flow of fuel air at the outlet of the premix pre-evaporation pipe is widened. As a result, a backflow is generated in the central portion between the adjacent outlets, the flame in the combustion chamber is stabilized, and the fire transfer from the pilot combustion portion can be improved.

Further, according to the gas turbine combustor of the present invention , reduction of NOx in exhaust gas can be further promoted.

Therefore, according to the present invention, by using the fuel having the improved mixing property with the air, the entire region inside the combustion cylinder is effectively used as the combustion region from the time of ignition to the high output.
As a result, it is possible to provide a gas turbine combustor that simultaneously achieves a reduction in the length of the combustor and a reduction in nitrogen oxides.

[Brief description of drawings]

FIG. 1 is a sectional view showing a gas turbine combustor of the present invention.

2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a graph showing the amount of nitrogen oxides in a gas turbine engine using the gas turbine combustor of the present invention.

[Explanation of symbols] 1 gas turbine combustor 2 Compressor side 3 combustion cylinder 4 Fuel nozzle section 9 Combustion chamber bulkhead 10 Combustion chamber 11 Pilot combustion section 12 Pilot fuel injection valve 13 Flame retaining cylinder (pilot flame retaining cylinder) 14 Fuel supply section 15 Lean fuel supply section 16 Main fuel injection valve (air flow atomization type fuel injection valve) 17 Premixing pre-evaporation pipe 17a Outlet of premixing pre-evaporation pipe 18 air swirler 22 aperture 22a swirl vane 23 Spark plug

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidemi Fuji, 229 Tonogaya, Mizuho-cho, Nishitama-gun, Tokyo Ishikawajima Harima Heavy Industries Ltd. Mizuho factory (56) Reference Japanese Patent Laid-Open No. 2-259331 (JP, A) Kaihei 2-195987 (JP, A) JP 4-332315 (JP, A) JP 4-256404 (JP, A) JP 2-107363 (JP, A) JP 4-103916 ( JP, A) Actual Kaihei 4-73706 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F23R 3/00-7/00

Claims (4)

(57) [Claims] 1. A fuel nozzle section for mixing compressed air sent from a compressor and fuel and for igniting fuel, and fuel continuously arranged and supplied to the latter stage side through the fuel nozzle section and a combustion chamber partition wall. A gas turbine combustor having a combustion tube of an integral annular structure for burning a plurality of fuel nozzles, wherein the fuel nozzle section has a plurality of outlets arranged concentrically over the circumferential direction of the central portion of the annular combustion chamber partition wall. And a pilot combustion part of, arranged on concentric circles of a diameter larger and smaller than the pitch circle of the pilot combustion part,
And a plurality of lean fuel supply parts arranged so that their outlets are located near the outlets of the pilot combustion parts of the combustion chamber partition walls, and an ignition plug for igniting the fuel in the pilot combustion parts. The pilot combustion unit is composed of a pilot fuel injection valve and a pilot flame holding cylinder connected to the tip of the pilot fuel injection valve,
The flame is structured to extend from the pilot flame holding cylinder to the inside of the combustion cylinder, and the lean fuel supply part is a main fuel injection valve for increasing the mixing amount of compressed air to supply the lean fuel to the combustion cylinder. this has been connected to the front end portion of the main fuel injection valve consists of a mixing and premixing pre-vaporization tube which promotes fuel vaporization of the fuel with the compressed air, the main fuel injection valve, the fuel by the air flow swirling The granules
It consists of an air atomization type fuel injection valve that atomizes, and a premixing pre-evaporation pipe is installed at the tip of the air flow atomization type fuel injection valve.
An air swirler is provided to swirl the supply airflow into the interior
Air flow and air flow of the atomizing fuel injection valve
A gas turbine combustor characterized in that the swirling direction of the air flow from the air swirler is set to be opposite . 2. The gas turbine combustor according to claim 1 , wherein a conical throttle for accelerating the air flow to the combustion cylinder is provided at the outlet of the premixing pre-evaporation pipe. Combustor. 3. The gas turbine combustor according to claim 2 , wherein the member for fixing the throttle has a swirl vane structure for swirling the flow of the air-fuel mixture. 4. The gas turbine combustor according to any one of claims 1 to 3, wherein the compressed air sent from the compressor is all the air except the cooling air sent to the combustion cylinder. The gas turbine combustor, characterized in that the gas turbine combustor is supplied to the lean fuel supply section.