JPH0953822A - Annular type combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate defect such as instability in holding flame by mutual interference of spiral flows generated by swirlers adjacent to each other or the generation of an unexpected flow in a liner in an annular type combustor which has swirlers arranged in a ring at an equal pitch to form a recirculation flow by generating the spiral flows in compressed air introduced into a liner. SOLUTION: A planking 16 extending radially and axially is arranged at an intermediate part between adjacent ones 6 of swirlers 6 at an equal pitch circumferentially in a circular combustor dome 15 arranged at the front end part of a liner 13. As a result, spiral flows generated by each of the swirlers 6 generate recirculation flow on the post flow side of the swirlers 6 separately without causing a mutual interference therebetween thereby enabling stabilization of combustion within the liner 13. There is no unexpected flow in the liner 13 otherwise caused by the mutual interference generated thereby enabling production of a combustor with excellent combustion efficiency and cooling efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an annular combustor applied to a combustor such as an aeronautical gas turbine engine.

[0002]

2. Description of the Related Art An example of a conventional gas turbine combustor is shown in FIG. 4, which shows a partial longitudinal section.

In the figure, the air that flows in from the compressor through the diffuser inlet portion 1 has a blunt shape that projects forward from the annular pre-diffuser casing 2 and the combustor dome 15 that defines the tip portion of the liner 13. The cowl 3 distributes the inner and outer annular passages 4, 5 and the cowl 3 in three directions as indicated by arrows. The latter of these is mainly the swirler 6, that is, the air swirler (air swirler) in the combustion chamber.
irler) forms a recirculation region, and the former flows into the combustion chamber inside the liner 13 through the air holes 7 or the cooling structure 8 provided in the inner and outer liners 13, respectively. Further, a part of the amount of air flowing through the inner and outer annular passages 4 and 5 is extracted for use in cooling the turbine or the like.

The fuel is a fuel injector 9 of a concentric double vortex chamber.
Is sprayed from the center of swirler 6 and swirler 6
And the flame holding circulating flow formed from air hole jets and the like. Furthermore, the air that flows into the liner 13 through the air holes in the latter half of the liner 13 completes combustion,
It is used to adjust the gas temperature distribution at the combustor outlet 10.
Further, 11 and 12 are an inner cylinder and an outer cylinder, which are respectively connected to the rear end of the pre-diffuser casing 2 and accommodate the annular liner 13 therein.

FIG. 5 is a schematic view showing the state of the air flow on the downstream side of the swirler 6 of the gas turbine combustor, and as described above, the pre-diffuser casing 2 is used.
Part of the air that has passed through is in the circumferential direction of the combustor dome 15,
The liner 13 is guided by the swirlers 6 provided at equal pitches.
A swirl flow SF is generated inside the. Further, the swirling flow SF induces a recirculation region CF to form a backflow region in the main combustion region. This backflow region allows the high temperature reactive species to
By supplying unburned gas in the downstream of the swirler 6, stable continuous combustion, that is, stabilization of the flame is realized.

However, the above-mentioned conventional gas turbine combustor has the following problems.

(1) As shown in FIG. 6 which is a view taken along the line BB of FIG. 5, the swirlers 6 arranged in an annular shape between the outer cylinder 12 and the inner cylinder 11 are adjacent to each other. The swirling flow SF formed by the interference of the swirling force weakens the swirling force, the recirculation flow region becomes smaller, and the reverse flow region formed in the main combustion region becomes smaller, so that the swirler 6 wake of the high temperature reaction active species does not flow. The supply to the fuel gas flow is reduced and the flame becomes unstable. (2) Similar to (1), the swirling flows SF interfere with each other to generate a small vortex SC between the adjacent swirlers 6, This contributes to unstable combustion in the main combustion region.

(3) Similar to (1), due to the interaction of the swirling flow SF, in the circumferential direction of the annular combustor 15, the swirlers 6 are arranged at equal pitches on the outer peripheral side and the inner peripheral side. A large eddy LC is generated, which affects the entire flow inside the liner 13.

[0009]

DISCLOSURE OF THE INVENTION The present invention is directed to the above-mentioned conventional gas turbine combustor, and in particular, the swirlers are arranged at equal pitches in the circumferential direction of the annular combustor dome that defines the front end of the liner. In an annular combustor, mutual interference of swirling flows generated by adjacent swirlers is reduced or eliminated to induce a large recirculation flow inside the liner to form a large backflow region. Or small swirls between the swirlers can be prevented to improve the stable combustion of the supplied fuel and the stability of the flame, and also to prevent the generation of large-scale swirls in the liner. Thus, it is an object of the present invention to provide an annular combustor in which the flow inside the liner is changed to a flow that improves the performance of the gas turbine combustor.

[0010]

Therefore, the annular combustor of the present invention has the following means. An outer peripheral edge of the fuel injector outlet end is formed on an annular combustor dome that partitions the liner tip and supplies fuel to the inside of the liner. From the middle part of the swirler and the swirler arranged along the circumference of the combustor dome at equal pitch.
A threshold plate is provided that projects toward the wake side of the liner and prevents mutual interference of swirling flows generated by adjacent swirlers. The threshold plate is preferably arranged so as to face the radial direction of the annular combustor dome.

In the annular type combustor of the present invention, the swirl flow generated by each of the adjoining swirlers by the above-mentioned means is separated by the threshold plate and generated by each of the adjoining swirlers. It is possible to prevent the swirling fellows from interacting with each other. This prevents the reduction of the backflow region in the main combustion region, which was caused by the interaction of the swirling flows generated by the adjacent swirlers, and prevents the generation of small vortices and stabilizes the main combustion region. Continuous combustion is possible.

Further, the large vortices generated in the outer peripheral portion and the inner peripheral portion of the swirlers arranged at equal intervals in the circumferential direction of the annular combustor dome are eliminated, and the flow inside the liner is disturbed. Introduction of air into the liner without
Alternatively, it is possible to prevent occurrence of a phenomenon such as cooling that is not desirable for improving the performance of the gas turbine combustor.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an annular combustor of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a first embodiment of an annular combustor of the present invention,
2 is a partial vertical cross-sectional view of a gas turbine combustor having the configuration shown in FIG. 1, and FIG. 3 is a front view taken along the line AA of FIG. The same reference numerals as those shown in FIGS. 4 to 6 are the same or similar members, and the description thereof will be omitted.

As shown in the figure, the fuel injector 9 is attached to the annular combustor dome 15 which defines the front end of the liner 13 and which has the outlet end of the fuel injector 9 penetrating through at an equal pitch in the circumferential direction. A swirler 6 is provided along the outer peripheral edge of the outlet end of the swirler.

Further, in the middle portion of the swirlers 6 arranged at equal pitches in the circumferential direction of the combustor dome 15 and the swirlers 6 provided adjacent to each other, the front end is on the back surface of the combustor dome 15, A threshold plate 16 having outer diameter ends fixed to the inner and outer liners 13 is provided. As shown in FIG. 3, the threshold plate 16 is oriented in the radial direction of the combustor dome 15 and its width direction is oriented toward the wake side in the axial direction of the liner 12. The length of the threshold plate 6 in the width direction, that is, the length of the liner 12 in the axial direction is adjusted to a length that ensures flame propagation between the swirlers 6. Further, such threshold plates 16 are arranged between the swirlers 6 in the same number as the swirlers 6 at equal pitches in the circumferential direction of the annular combustor dome 15.

As described above, since the annular type combustor of the present embodiment is constructed, the swirling flow generated by the swirler 6 is separated by the threshold plate 16, each of them becomes an independent flow, and the mutual flow of the flows. The influence of the interference on the combustion flow field is avoided in advance. Therefore, a large recirculation flow is formed in the wake side of the swirler 6, that is, in the main combustion area inside the liner 13, and the high temperature reactive activated species burned in the main combustion area becomes unburned gas in the wake of the swirler 6. The stable supply enables stable and continuous combustion, that is, stabilization of the flame. In addition, a small vortex is not formed between the adjacent swirlers 6, and the instability of combustion due to the small vortex does not occur.

Further, the outer peripheral portion of the annular combustor dome,
And a large vortex that goes around the inner peripheral part
Is not formed, and the performance of the gas turbine combustor, which is caused by the generation of a flow that swirls in the circumferential direction inside and outside the liner 13, is not caused.

[0018]

As described above, according to the annular combustor of the present invention, the structure shown in the claims makes
A swirl flow interfering with each other is prevented by a threshold plate provided in the middle part of the swirler provided at equal pitch in the circumferential direction of the annular combustor dome. In addition, the instability of combustion in the main combustion zone due to the reduction of recirculation flow in the liner and the generation of small vortices, and the undesired phenomenon to the internal flow of the liner due to the generation of large eddies can be eliminated. The performance of the gas turbine combustor can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of an annular combustor of the present invention,

2 is a partial longitudinal cross-sectional view of a gas turbine combustor having the configuration shown in FIG. 1,

FIG. 3 is a front view of the arrow AA shown in FIG.

FIG. 4 is a partial vertical sectional view of a conventional annular combustor,

5 is a schematic diagram of the annular combustor shown in FIG. 4,

6 is a front view taken along the line BB shown in FIG.

[Explanation of symbols]

 1 Diffuser inlet 2 Pre-diffuser casing 3 Cowl 4 Inner annular passage 5 Outer annular passage 6 Swirler 7 (Liner) Air hole 8 (Liner) Cooling structure 9 Fuel injector 10 Combustor outlet 11 Inner cylinder 12 Outer cylinder 13 Liner 15 Combustion Vessel dome 16 threshold plate

Claims (1)

[Claims] 1. A liner coaxially arranged in an annular outer cylinder, a tip end portion of the liner, and an outlet end portion of a fuel injector for supplying fuel into the liner are circumferentially arranged. A combustor dome provided penetrating at an equal pitch, and disposed on the combustor dome along the outer peripheral edge of the outlet end of the fuel injector to generate a swirling flow in the compressed air from the pre-diffuser, In an annular combustor having a swirler that forms a recirculation flow region in the liner and stabilizes the combustion flame in the liner, from the combustor dome in the middle of the adjacent swirlers to the inside of the liner. An annular combustor provided with a threshold plate which is provided to project toward each other and which regulates mutual interference of swirling flows generated by each of the adjacent swirlers.