JP2002004884A - Cooling structure for combustor wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling structure for a combustor wall which can attain prolonging of service life for use, by placing a connection part of brazing or the like in a cooling jacket as for distant as possible from combustion gas to reduce thermal stresses. SOLUTION: In this cooling structure for a combustor wall, formed with cooling jackets 5A by constituting a tail cylinder 4 of a multi-nozzle type premixed combustor 3 by a double wall to apply groove work to one wall 4a thereof and braze the other wall 4b to the side applying this groove work, one wall 4a applying the groove work is placed on an inner wall side exposed in combustion gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a combustor wall of a gas turbine combustor or the like.

[0002]

In recent years, as a gas turbine combustor, which can also be low NO _X is achieved, for example, 1500 ° C. class gas turbine, a steam cooled combustor has attracted attention. That is, by cooling the wall of the combustor with steam, the air previously used for cooling the wall is used for combustion, so that the premixed combustion temperature can be reduced despite the high temperature of the gas turbine. it is the low NO _X reduction is possible by suppressing the tears.

[0003] Such steam cooling involves, for example, premixing of the main fuel and the combustion air around the cone 1 where the pilot fuel and the combustion air react to form a diffusion flame as shown in FIG. It is used for cooling the transition piece 4 of a multi-nozzle premixed combustor 3 in which a premixed flame forming nozzle 2 for forming and ejecting gas is divided and arranged in a plurality.

[0004] According to this, the cooling steam is first supplied to the middle portion of the transition piece 4 in the longitudinal direction (see the manifold 6b) by the cooling jacket 5 (see FIG. 4) formed on the wall surface of the transition piece 4 and the manifolds 6a, 6b, 6c. ), From which it is diverted to the upstream and downstream sides of the gas flow as shown by arrows in the figure to cool the wall surface, and then cooled to the inlet portion of the transition piece 4 (the manifold 6a).
And the outlet (see the manifold 6c).

Further, the cooling jacket 5, as shown in FIG. 4, D ₁ on one wall 4a of the transition piece 4 composed of a double wall =
Grooving of D ₂ formed by for brazed to the other wall 4b on the side that groove machining with (see grooved section b) (see brazing portion b), and an outer wall of said groove processed the one wall 4a And side.

[0006]

However, in the conventional cooling structure for a combustor wall as described above, a groove is formed on one wall 4a of a transition piece 4 having a double wall and the groove is formed. The other side wall 4b, which is thinner than the same side wall 4a, is brazed to the processed side to form the cooling jacket 5, and the grooved one side wall 4a is used as the outer wall side. Since the brazing portion B having a low creep strength is located in an atmosphere at a high temperature due to the combustion gas, there is a problem that thermal stress is increased and a peeling phenomenon occurs in the brazing portion B.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and a joint portion such as brazing of a cooling jacket is reduced as much as possible from a combustion gas to reduce a thermal stress, thereby extending a service life. An object of the present invention is to provide a cooling structure for a container wall.

[0008]

According to the present invention, there is provided a cooling structure for a combustor wall according to the present invention, wherein the combustor wall is formed of a double wall, and a groove is formed in one of the walls. In the cooling structure for a combustor wall in which a cooling jacket is formed by joining the other wall to the grooved side, the grooved one wall is an inner wall exposed to combustion gas.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a cooling structure of a combustor wall according to the present invention.

FIG. 1 is a side sectional view showing a gas turbine combustor according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line II-II of FIG. In these figures, FIG.
4 and the same members and portions as those in FIG. 4 are denoted by the same reference numerals, and detailed description is omitted.

As shown in FIG. 1, premixing of a premixed gas of main fuel and combustion air is formed and ejected around a cone 1 where a pilot fuel and combustion air react to form a diffusion flame. The present invention is applied to steam cooling of the transition piece 4 of the multi-nozzle premixed combustor 3 in which the flame forming nozzle 2 is divided and arranged in a plurality.

In this embodiment, the cooling steam is supplied to the transition piece 4.
The cooling jacket 5A (see FIG. 2) and the manifolds 6a and 6c formed on the wall surface of the air conditioner first supply the outlet of the transition piece 4 (see the manifold 6c), from which the gas flows upstream as indicated by the arrow in the figure. After cooling down the wall surface, it is recovered from one location at the entrance of the transition piece 4 (see the manifold 6a).

[0013] The cooling jacket 5A, as shown in FIG. 2, D ₁ on one wall 4a of the transition piece 4 composed of a double wall
<Grooving of D ₂ formed by for brazed to the other wall 4b on the side that groove machining with (see grooved section b) (see brazing portion B), and one wall 4a that the grooving The inner wall is exposed to combustion gas.

In this embodiment, the other wall on the outer wall side is used.
4b has a greater thickness than before in consideration of the strength during bending.
It is formed slightly thicker. In addition, the one wall 4a is also
The strength of the brazing part B at the same pitch of the racket 5A
Groove depth D to prevent lowering _TwoTo increase the passage cross-sectional area
In order to increase the thickness, the plate thickness is made as thick as possible
Have been.

As described above, in the present embodiment, since the grooved one wall 4a is on the inner wall side exposed to the combustion gas, the brazing portion B of the cooling jacket 5A is kept as far as possible from the combustion gas. The temperature rise due to the combustion gas can be prevented.

[0016] As a result, it is possible to prevent the occurrence of the peeling phenomenon in the brazing portion B due to an increase in thermal stress as in the prior art, and to extend the service life of the combustor wall. In addition, the longitudinal groove of the cooling jacket 5A provides a flexible wall structure to further reduce the thermal stress and increase the heat transfer area, so that steam (the present invention may be air) as a cooling medium is used. The amount can be reduced, and the performance of the plant can be improved.

In this embodiment, the cooling jacket 5A and the manifolds 6a and 6c perform steam cooling from the outlet to the inlet of the transition piece 4 in one pass, so that the steam before the temperature rises due to heat exchange. (The present invention may be air)
Thereby, the exit part of the transition piece 4 can be cooled.

As a result, the metal temperature is lowered, the low cycle fatigue life is improved, and the occurrence of cracks at the four corners of the exit portion of the transition piece 4 due to increased thermal stress as in the prior art is avoided. At this time, as described above, by increasing the cross-sectional area by increasing the depth D _2, it is possible to ensure the same steam flow as before while preventing the reduction in strength of the brazed portion b. In addition, because it is steam cooled in one pass,
The number of jackets and manifolds can be reduced,
The structure can be simplified.

It should be noted that the present invention is not limited to the above embodiment, and the cooling jacket structure as shown in FIG. 2 can be replaced with a two-site recovery type steam as shown in FIG. 3 without departing from the gist of the present invention. Needless to say, various changes such as application to cooling are possible.

[0020]

As described above in detail with reference to the embodiments, in the invention according to claim 1 of the present invention, the combustor wall is constituted by a double wall, and a groove is formed in one of the walls. In addition, in the cooling structure of the combustor wall in which the other wall is joined to the grooved side to form a cooling jacket, the grooved one wall is an inner wall exposed to combustion gas. It is possible to realize a cooling structure for the combustor wall that reduces the thermal stress by keeping the joint such as brazing of the jacket as far as possible from the combustion gas and prolongs the service life.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing the periphery of a gas turbine combustor showing one embodiment of the present invention.

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

FIG. 3 is a side sectional view showing a gas turbine combustor around a conventional example.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

[Explanation of symbols]

 Reference Signs List 1 cone 2 premixed flame forming nozzle 3 multi-nozzle premixed combustor 4 transition piece 5,5A cooling jacket 6a, 6b, 6c manifold

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsunori Tanaka 2-1-1, Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Works, Mitsubishi Heavy Industries, Ltd. (72) Inventor Mitsui Hasegawa 2-1-1, Aramachi-Niihama, Takasago-shi, Hyogo Prefecture No. 1 Inside the Mitsubishi Heavy Industries, Ltd. Takasago Factory

Claims (1)

[Claims] 1. A cooling structure for a combustor wall in which a combustor wall is formed of a double wall, one of the walls is grooved, and the other wall is joined to the grooved side to form a cooling jacket. A cooling structure for a combustor wall, characterized in that the grooved one wall is an inner wall exposed to combustion gas.