JPH031015A - Gas turbine combustion device - Google Patents

Abstract

PURPOSE:To provide a uniform, stable and continuous supplying of combustion air by a method wherein a sleeve and a transition piece are formed with a plurality of holes, and a hole in the sleeve and another hole in the transition piece are made different in their relative positions. CONSTITUTION:Air compressed by a compressor 2 may flow into an air chamber 21 formed by a combustion air casing 5 and a combustion inner casing 6. An air flow passage for cooling a transition piece 13 and an air flow passage reacting with fuel flowing between a liner outer cylinder 11 and an inner cylin der 12 are separately formed. Discharged air from the compressor 2 may flow with a disturbed high frequency. Since the air chamber 21 has an effect of keeping a stillness, a substantial attenuation is attained, the air may flow a spacing between the liner outer cylinder 11 and the inner cylinder 12 and further the air may flow from the combustion air holes 22 made in the inner cylinder 12 into a combustion chamber 12a of the inner cylinder 12. Air flowing between the liner outer cylinder 11 and the inner cylinder 12 passes through air holes formed in a swirler 23 and flows into the combustion chamber 12a. The air may provide a strong circulating energy when it passes through the air holes of the swirler 23 so as to promote a stable combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION Field of the Invention The present invention relates to gas turbine combustors, and more particularly to gas turbine combustors that use air to cool a combustor transition piece.

(Prior Art) Conventionally, a transition piece cooling structure for a gas turbine combustor, as disclosed in Japanese Unexamined Patent Application Publication No. 62-218732, has provided a flow sleep in the combustor transition piece, and a part of the flow sleep has been provided with a flow sleep. This method cools the transition piece by drilling holes in it and blowing cooling air toward the transition piece.

A conventional combustor transition piece is constructed as shown in Fig. 11, in which a part of the compressed air compressed by the compressor a is ejected from the cooling hole C drilled in the flow sleep b and flows into the transition piece d. to cool down. The holes drilled in Flow Sleep b include large diameter air holes e for air intake in addition to the small diameter cooling holes C, and the air blown out from each of these holes C1e flows through Flow Sleep B and Transicicon Bead d. The air flows between the combustor Flow Sleep R and the liner 0, and is used for cooling the combustion air and the liner Q.

(Problem to be Solved by the Invention) However, although the transition piece d of the gas turbine combustor has a circular cross section at the connection part with the liner Q, the connection part with the turbine h has a circular cross section as shown in FIG. It is almost fan-shaped.

Therefore, the air passage i also becomes approximately fan-shaped, resulting in flow sleep b! - The air flowing between the transition bead d has different flow resistance, and the flow is biased towards the axis of the gas turbine and flows into the combustor.

That is, the circumferential distribution of the flow between the combustor flow sleep f and the liner 9 shown in FIG. 11 is shown by a broken line in FIG. In this conventional example, the amount of air flowing in is large on the gas turbine rotation axis side, and on the contrary, it is decreasing on the outside. When considering the combustion state when such air flow distribution is achieved, as shown in Fig. 10, there is an unevenness in the mixture ratio of fuel and air (fuel-air ratio) between the gas turbine rotation axis side and the outside. Therefore, it is not equal. The mixture ratio of fuel and air is an important factor in combustion, and the higher this value, the more stable the combustion will be.
When it becomes small, the flame disappears and combustion cannot be sustained.

By the way, in conventional gas turbine combustors, the fuel-air ratio was set to a value higher than the flammability limit to ensure stable combustion, but now the nitrogen oxides (
Lean burn (NOx) with a small fuel-air ratio is used to reduce
low temperature combustion) is required. In order to perform such lean combustion, the fuel-air ratio is set close to the flammability limit, so as mentioned above, jI! If the air flow type is uneven in the circumferential direction of the burner, there will be areas where the flammability limit is partially exceeded, and as a result, unburned components such as carbon monoxide (CO) and hydrocarbons (
LJHC) will be discharged multiple times.

In such cases, combustion becomes extremely unstable and large pressure fluctuations occur inside the combustor liner, which can cause cracks in the liner, which is a combustor component, cracks in flow sleep welds, and wear at connections. etc., which necessitates repair or replacement of parts, and also excites the entire gas turbine, causing excessive vibrations that may cause the gas turbine to stop.

The present invention has been made in consideration of the above circumstances, and provides a gas turbine combustor that continuously and uniformly supplies combustion air even though lean combustion is performed to reduce exhaust gas. The purpose is to

[Structure of the invention]

(Means for Solving the Problems) A gas turbine combustor according to the present invention forms a combustion air flow path between a liner outer cylinder and a liner inner cylinder, and has a transition section for guiding combustion gas to the liner inner cylinder. In the turbine combustor, a sleeve is arranged at a predetermined interval around the transition bead, and a plurality of holes are bored in the sleeve and the transition piece, The combustion air flow path and the transition piece air flow path are formed separately by arranging the holes in the sleeve and the holes in the transition beads 1 to 1 in different relative positions.

(Function) In the present invention having the above configuration, compressed air flows separately into air that cools the transsion piece and air that flows through the combustion air flow path and reacts with the fuel. This combustion air cools the inner cylinder of the liner and reacts with the fuel to generate N temperature combustion gas, which drives the turbine. +J. Further, the air flowing in from the outer periphery of the transition piece hits the transition piece as a jet through the hole bored in the sleeve, thereby cooling the transition piece. Therefore, the air flowing through the transition piece is stable and flows evenly, so that a healthy temperature is maintained and combustion instability is eliminated.

(Tsuura Example) Hereinafter, an embodiment of a gas turbine combustor according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a gas turbine combustor according to the present invention. A gas turbine combustor 1 is provided between a compressor 2 and a gas turbine 4 that drives an RTi machine 3.
It is housed between an outer combustor casing 5 and an inner combustor casing 6 defining a discharge chamber from the combustor. The combustor outer casing 5 and the combustor inner casing 6 are compressor 1
2 and each casing of the gas turbine 4 are integrally or integrally connected, and a plurality of gas turbine combustors 1, for example, 10 or 14 gas turbine combustors 1, are arranged in the circumferential direction inside the combustor outer casing 5.

The gas turbine combustor 1 includes a liner outer cylinder (combustor flow sleep) 11 and a liner inner cylinder 12 that constitute the combustor main body.
(combustor liner) into a double cylinder structure, and its annular space is defined as a combustion air flow path 11a. A combustion chamber 12a is defined within the liner inner cylinder 12, and fuel and combustion air are supplied into the combustion chamber 12a, mixed, and subjected to combustion. Further, a combustor head plate 16 is provided in the combustor internal casing 6, and a fuel nozzle set 17 is attached to this head plate 6.

On the other hand, a sleeper 23 is provided at the tip of the liner inner cylinder 12, and the air flowing between the liner outer cylinder 11 and the inner cylinder 12 is given strong swirling energy when it passes through the air hole of the sleeve 23. Further, an I-transition piece 13 is attached to the rear end of the liner inner cylinder 12, and a sleeve 14 is disposed around the outer periphery of the transition piece 13 to cover it at a predetermined interval.

A large number of circular cooling holes 24 are bored in the sleep 14 as shown in FIGS.
erupts towards. And transition piece 13
A pellet-shaped or cylindrical heat transfer promoter 15 is provided on the circumferential surface of the sleeve 14 to disturb the cooling air from the cooling holes 24 .

Although the sleeve 14 and the transition piece 13 are in contact with each other via the heat transfer promoter 15, they are not joined together, and a predetermined distance G is maintained at atmospheric temperature to absorb thermal expansion. Also,!・Multiple circular film cooling holes 26 in the transition bead 13
is drilled, and this cooling hole 26 is the same as the cooling hole 2 of the sleep 14.
They are arranged at different relative positions so that the removal air blown out from 4 cannot be blown directly.

Furthermore, sleep 14 and 1 to transition bead 1
3 is supported by a front support 19 and a rear support 20, and the front support 19 is fixed to the sleep and transition piece 13 so as to be extendable in the axial direction of the gas turbine, and the contact sabot I/20 is surrounded by the sleep 14. Since this is difficult, as shown in FIG. 3, another impingement plate 27 and a heat transfer accelerator 15 are provided so that the transition piece support portion can also be cooled uniformly.

Next, the operation of this embodiment will be explained.

The air compressed by compression 8!2 flows into the air chamber 21 formed by the combustor outer casing 5 and the combustor inner case/sink 6, and is connected to an air flow path that cools the transition piece 13 and to the liner outer cylinder 11. An air flow path that flows between the inner cylinder 12 and reacts with the fuel is formed separately. here,
The discharged air from the compressor 12 enters with high-frequency turbulence, but because the air chamber 21 has a calming effect, it is greatly attenuated and flows between the liner outer cylinder 11 and the inner cylinder 12, causing the inner Combustion air flows into the combustion chamber 12a of the inner cylinder 12 through a plurality of combustion air holes 22 formed in the cylinder 12.

Furthermore, the air flowing between the liner outer cylinder 11 and the inner liner cylinder 11 passes through the air hole provided in the sleeve 23 and enters the combustion chamber 1.
2a. When the air passes through the air holes of the sleeper 23, strong swirling energy is given to the air, which improves the mixing with the fuel in the combustion chamber 12a and stabilizes combustion. The high-temperature combustion gas combusted in the combustion chamber 12a is guided by the transition piece 13 to the inlet of the gas turbine 3 through a flow path having a circular cross section.

On the other hand, a portion of the air that has flowed into the air chamber 21 is guided to the transition piece 13 for cooling purposes. As shown in FIG.
(By ejecting!), the transition piece 13 is hit as a jet and convection cooling is performed.Then, the cooling air that has cooled the surface of the transition piece 13 is transferred to the heat transfer promoter 2.
5, the cold W airflow is further disturbed, the cold air flows over the surface of the transition piece 13, and convective heat transfer is promoted. In this case, it is known that the cooling effect of the cooling air ejected from the sleeper 14 is maximum at the position of contact, and the heat transfer coefficient gradually decreases in the vicinity. Therefore, in order to uniformly cool the transition beads 13, it is preferable that the heat transfer promoter 15 be installed near the middle surfaces of the jets.

Next, the cooling air blown out between the sleeper 14 and the transition piece 13 cools the transition piece 13, passes through the film cooling holes 26 drilled in the transition piece 13, and then cools the transition piece 13.
Film cooling is performed by flowing on the inner surface of 3.

This film cooling lJ1 forms a thin film of cooling air between the combustion gas and the transition piece 13, making it possible to protect the i-transition piece 13 from the combustion gas. This film cooling air mixes and diffuses as it flows together with the combustion gas, and the efficiency decreases as it goes downstream, so a large number of film cooling holes 26 are bored in the transition piece 13 to maintain high film cooling efficiency. It looks like this.

That is, in this embodiment, compressed air flows into the air chamber 20 by the compressor 2, air that cools the transition piece 13 and air that reacts with the fuel flow separately, and the air that flows into the combustion chamber 172a flows into the air chamber 20. It cools the cylinder 12 and reacts with the fuel to generate high-temperature combustion gas, which drives the gas turbine 4. On the other hand, as shown in FIG. 2, the air flowing from the outer periphery of the transition piece 13 hits the transition piece 13 as a jet through the cooling holes 24 formed in the sleeper 14, thereby cooling the transition piece 13. Here, a heat transfer accelerator 25 is provided in the area around the jet where the cooling efficiency has decreased,
The entire surface of the transition piece 13 is heated and cooled evenly. This cooling air is blown out from a film cooling hole 26 formed in the 1-range transition piece 13 and flows toward the gas turbine 4 while protecting the transition piece 13 from combustion gas by forming a film air layer.

In this way, according to this embodiment, F-yaki! 12a and the transition piece 13 are formed separately, combustion of the fuel with 8-thickness can be performed stably, and as a result, low NOx in the combustion exhaust gas is achieved, and CO2 is reduced. It is possible to provide a gas turbine combustor that emits significantly less UHC and UHC. In addition, since the air flow is constant and uniformly distributed in the combustor 1, unstable pressure fluctuations within the combustor 1 are eliminated, and the liner outer cylinder
1. Transition piece 13 and front and rear support 1
9.20 etc. cracks and wear are significantly reduced and reliability is improved. In addition, since the cooling air distribution in the liner outer cylinder 11 and the transition piece 13 is stable and unevenness does not occur, phenomena such as a partial lack of cold W do not occur, and reliability can be further improved.

FIGS. 4(A), (B), and (C) show other embodiments of the sleep, and the sleep 14 shown in FIG. A plurality of fittings 18 for connecting and fixing are provided on the dividing surface of the halves 14a and 14b, and FIG. Extend the sleep half body 14a.

14b is connected. The connecting parts can be connected by welding, bolts, etc., and the seven flange 32 of both the sleep halves 14a and 14b can be connected and fixed with a plurality of stop plates 29 as shown in FIG. 4(C). Figure 5 (A
), the stop plate 29 has a spring effect,
Both flanges 32 may be elastically held.

Furthermore, as shown in FIG. 5(B), unevenness may be formed on the contact surfaces of the flanges 32 to prevent the connection portion from shifting. The sleep half body 14a214b can also be positioned using a bin (not shown).

Further, the sleeve 14 and the transition bead 13 may have a slide portion 33 fixed to the end of the sleeve 14 to allow for large elongation due to heat, as shown in FIG. 6 (Δ). is liner outer cylinder 11
In addition to the side, they can be placed on the turbine side or in between, and a plurality of them can be provided. Instead of the slide portion 33, the end portion of the sleeve 14 may be bent to form a bellows 30 as shown in FIG. 6(B), and the bellows 30 may absorb elongation due to heat.

Furthermore, the shape of the heat transfer promoter 15 may be a conical shape as shown in FIG. 7 (A>) in addition to the cylindrical shape shown in FIG.
In short, any material that induces turbulence so as to supply new cold W air to the surface of the transition piece 13 may be used.

In addition, by providing the film cooling holes 26 in the transition piece 13 at an angle as shown in FIG. 7(B), the film cooling efficiency can be further increased. It may be a long hole, and the diameter may be larger than that of the cooling hole 24 of the sleeper 14.

And sleep 14 and] transition bead 1
The plate thickness of No. 3 is not limited to the above example.
Even if 1 is made thicker or the same, the same effect is obtained.

In addition, the cooling holes 24 of the sleep 14 and the heat transfer promoter 1
5 is not limited to the above embodiment, and the arrangement and spacing thereof may not be constant. The heat transfer promoter 15 is not necessarily attached to the transition piece 13, but may be attached to the sleeper 14 or both.

FIG. 8(A) shows another embodiment of the liner outer cylinder, and as shown in this figure, the tip of the liner outer cylinder 11 is curved in the outer circumferential direction to provide an inlet guide 31 for combustion air.
This inlet guide 31 allows air to flow uniformly into the combustion air flow path 11a, and in particular, stabilizes the combustion state.

FIG. 8(B) shows an inlet guide 31 formed into a hollow pipe shape and welded to the liner outer cylinder 11. This inlet guide 31 serves both as a guide member and a reinforcing member.
In addition to the function of the entrance guide 31 in A), the strength can also be increased. If the liner outer cylinder 11 and the transition piece 13 are close to each other, as shown in FIG. 8(A).
, (B), if the end face of the transition piece 13 is shaped with the corners cut off, the inflow of air can be made even more uniform. As shown by solid lines in FIGS. 9 and 10, the circumferential distribution of air and the circumferential distribution of the fuel-air ratio can be made uniform.

〔Effect of the invention〕

As described above, in the gas turbine combustor according to the present invention, the air flowing through the liner inner cylinder and transition piece is stable and flows evenly, so each part is maintained at a healthy temperature and combustion instability is avoided. do not have. As a result, rare illumination near the flammability limit! (Low fA) Combustion can be stably sustained, reducing NOx and unburned components (Co, L).
l) It is possible to reduce the amount of emissions of Ic), increase combustion efficiency, and improve the efficiency of the gas turbine combustor.

Also,! ! Since combustion instability can be prevented, damage to combustor parts can be eliminated, and a gas turbine combustor with significantly improved reliability can be provided.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a gas turbine combustor according to an embodiment of the present invention, and FIG. 2 (A>, (B)) shows a 1-transition bead cooling structure; > is an enlarged view, and (B) is B- in Figure 2 (A).
A sectional view taken along the line B, (C) is a sectional view taken along the line C-C of FIG. 2 (A), FIG. 3 is a sectional view showing the rear support of the transition piece, and FIGS. (C) is a perspective view showing another embodiment of the sleep, Figures 5 (A) and (B) are sectional views showing the joints of the sleep, and Figures 6 (A) and (B) are 1
~Cross-sectional view showing the ends of the lunge bead and sleeper,
FIGS. 7(A) and (B) are cross-sectional views showing other embodiments of the transition piece cooling structure, and FIGS. 8(A) and ([3) are cross-sectional views showing other embodiments of the tip of the liner outer cylinder. Figure 9 is an explanatory diagram showing the circumferential distribution of air at the combustor flow sleep inlet, and Figure 10 is an explanatory diagram showing the circumferential distribution of the flow rate ratio of fuel and air (fuel-air ratio) in the combustor liner. 11 is a partial sectional view showing a conventional gas turbine combustor, and FIG. 12 is a front view showing a connection portion of the transition piece shown in FIG. 11 with a turbine. 1... Gas turbine combustor, 2... Compressor, 4...
- Release 1! Machine, 11... Liner outer cylinder, 11a... Combustion air flow path, 12... Liner inner cylinder, 13... Transition piece, 14... Sleep, 15...
Heat transfer promoter, 24... cooling hole, 26... film cooling hole. Applicant's agent Hisashi Hatano B (A) (B) (C) Figure (A) CB) (A) CB) Figure (Outside #J) (#λ Nii Isu) (9HfP1) ( Foreign bonds j) (Xiaotun side) (MJ) Figure 1O

Claims (1)

[Claims] In a gas turbine combustor that forms a combustion air flow path between a liner outer cylinder and a liner inner cylinder and is provided with a transition piece that guides combustion gas to the liner inner cylinder,
Sleeps are arranged at predetermined intervals around the transition piece, a plurality of holes are bored in the sleep and the transition piece, and the holes in the sleep and the holes in the transition piece are arranged in different relative positions. A gas turbine combustor characterized in that the combustion air flow path and the transition piece cooling air flow path are formed separately.