JPS5941716A - Burner having ceramic refractory wall structure - Google Patents

Abstract

PURPOSE:To provide the burner of the ceramic refractory wall structure allowing high temperature combustion to be made and having a high degree of mechanical strength. CONSTITUTION:The inner surface 2a of an inner cylinder of the combustor of a gas turbine is attached with a refractory wall 27 consisting of a number of segments 28. The segment 28 is formed of a plate-like ceramic piece 29, a cover 30 for holding the ceramic piece 29 and a cushion 31 made of a material having elastic and ventilating properties and interposed between the cover 30 and the ceramic piece 29. As the ceramic piece 29 has an excellent heat resistant propperty, the inner cylinder 12 is prevented from being heated to high temperature, high temperature combustion in a combustion chamber 11 is made possible. Further, the ceramic piece 29 which has a low degree of strength is held by the cover 30 through the cushion 31 so that it is possible to improve the strength of the ceramic piece 29 against vibrations and to keep the mechanical strength of the entire combustor at a high level.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustor that is mainly used in gas turbines and has a ceramic refractory wall structure that enables high-temperature combustion by providing a ceramic refractory wall on the inner surface of the combustion chamber wall.

Gas turbine combustors are required to perform high-temperature combustion in order to save energy. This is because, as is well known, in gas turbines, thermal efficiency improves as the gas temperature at the turbine inlet increases, so in order to increase the gas temperature, it is necessary to increase the combustion temperature in the combustor. This is because

In order to increase the combustion temperature, the combustion chamber wall of the combustor must be made of a material that can withstand high temperatures and maintain mechanical strength. Therefore, in a conventional gas turbine combustor, as shown in FIG. 1, an outer cylinder 13 is provided around the outer periphery of an inner cylinder ν, which is the combustion chamber wall forming the combustion chamber U, and cooling air 14 is allowed to flow between the outer cylinders 13 and 13. At the same time as cooling the inner cylinder ν from the outside, a part of the cooling air 14 is introduced into the cooling air introduction (from 5 to the inner surface of Jr' 12) provided in the inner cylinder, By forming a film of cooling air 14 on this inner surface and thermally insulating the inner surface from high-temperature combustion gas, a decrease in mechanical strength due to the rise in temperature of the inner surface is prevented. In FIG. 1, 17 is a fuel injection nozzle, and 18 is a 7-warb.

However, the compressor (
Compressed air 19 from a tank (not shown) is used separately for combustion air and cooling air 14, so in order to increase the combustion temperature, a large amount of fuel must be burned relative to the total amount of compressed air 19. Therefore, the number of combustion air holes is required, and the amount of cooling air 14 is reduced accordingly. As a result, together with the increase in the temperature of the combustion gas, the inner cylinder is exposed to higher temperatures, which inevitably leads to a decrease in mechanical strength, and there are disadvantages in that a sufficiently high combustion temperature cannot be achieved.

The present invention was made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide a combustor with a cefmic firewall structure that is capable of high-temperature combustion and has high mechanical strength. .

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

In FIG. 2, reference numeral 12 denotes an inner cylinder of a combustor of a gas turbine, and is the combustion chamber wall itself that forms a combustion chamber 11 inside. 17 is a fuel injection nozzle, 1 is a nuwara, 3 is a combustion air hole, and 1 is a dilution air hole.

A fireproof wall (I) is attached to the inner surface of the inner cylinder (as shown in Fig. 3).
28 are arranged adjacent to each other.

As clearly shown in FIG. 4, the above segment 28 includes four plate-shaped ceramic pieces, a cover for holding the ceramic pieces, and a cover 30 interposed between the ceramic piece and the cover. The cushion body 31 is made of a resilient and breathable material, and its ceramic surface faces downward, ie, toward the inside of the inner cylinder. In addition, the screw body is brazed at the beginning of the cover, and this screw body is made to protrude outward from the inner cylinder, and the cover (material), that is, the segment) 28, is attached to the inner cylinder ν with the hollow (2) 35. It is installed.

The material of the ceramic piece is a combination of one or more of alumina, zirconia, silicon nitride, cordierite, silicon carbide, mullite, etc., and the cushion body 31 has an angle of 500° or more. [Materials that can withstand high temperatures and have elasticity and air permeability], for example, nickel, etc.
It is made of heat-resistant foamed metal made of chromium alloy, honeycomb-shaped or fibrous metal, ceramic, etc., and
The cover (material) is made of a metal material such as stainless steel that can withstand temperatures of several hundred degrees Celsius.

The inner cylinder is provided with a cooling air introduction hole 15 for film cooling, and the cooling air 14 is passed from the outside of the inner PiIJ 12 through the cooling air introduction hole 15 to the ceramic surface blade inside the segment 28. The cooling air 14 is introduced to form a film of cooling air 14 on the ceramic surface vanes. Furthermore, there are air holes 3 in the inner part 812 and the cover (material).
A cooling air introduction path 40 consisting of 7, 38, and 39 is provided to introduce cooling air 14 from the outside of the inner cylinder section into the breathable cushion body 31.

The assembly procedure for the segment 2B is shown in FIG. 5, and the segment 28 after assembly is shown in FIG. 6. Segment in Figure 5)
28, as shown in Fig. 2, is installed so that it is tilted backwards with respect to the axis 2 of the inner cylinder, so that the radius of curvature a of its leading edge is equal to the radius of curvature of the trailing edge 28b. As a result, as shown in FIG. 5, the length L of the leading edge island of the cover J is inevitably larger than the length M of the trailing edge, resulting in a tapered shape in plane. The ceramic piece and the cushion body 31 also have a planar tapered shape. In addition, the cover (
The side part aOC of the cover J is formed in a serpentine shape that tapers toward the inside. It is formed in a tabular shape that matches the . Therefore, the ceramic piece 9 and the cushion body 31 bonded to each other are inserted into the cover from the front side of the cover, and the retaining plate 6 is bonded to the front side of the cover. The cushion body 31 is firmly held by the cover in a state where it is prevented from being removed by the removal prevention plate part.

Examples of the above-mentioned joining means include welding, brazing, adhesion using a heat-resistant adhesive, diffusion joining, and mechanical joining. In addition, the shoe body 31 and the cover 30 may be joined together, or even if they are not joined, there is no problem with the cow and V.

FIG. 7 shows a modification of the means for attaching the segment 28 to the inner cylinder rim, in which an insertion hole 45 is provided that penetrates the reramik piece 4, the cushion body 31, and the cover (material), and a bolt 46 is provided.
A nut 47 attaches the segment passageway to the inner cylinder.

Segment 28 in Fig. 8 indicates the one having the combustion air hole in Fig. 2 at the rear, and segment) 28 in Fig. 9 indicates the one having the dilution air hole in the front as shown in Fig. 2. show. Since the pores δ and 26 of these segment paths are not completely circular holes but 1/4 holes, there is no risk of reducing the strength of the ceramic piece.

In the above configuration, as shown in FIG.
Ceramic piece thorn (segment) 28 has excellent heat resistance and has a large heat shielding effect, so it prevents the temperature of the inward direction ν from increasing and prevents high-temperature combustion in the combustion chamber 11 in Fig. 2. It becomes possible.

Here, the cover shown in Figure 4 is also prevented from becoming hot, so
This is economical because the cover J and the inner sleeve can be made of a low-grade metal material with relatively poor heat resistance.

In addition, the ceramic piece 9 with low strength is used as the cushion body 3.
Since the ceramic piece 4 is held in place through the cover 1, the vibration resistance of the ceramic piece 4 is improved, and the mechanical strength of the entire combustor is maintained at a high level.

Even if the combustor is damaged, other segments (28) are not affected, so the entire combustor will not be seriously damaged, and since it will not come into contact with the ceramic surface, hot spots caused by contact with the flame will not reach the ceramic surface. The problem that occurs in 32 and makes the ceramic piece thorns more likely to break does not occur. Moreover, the cushion body 31 is made of a breathable material,
By introducing the cooling air 14 into the cushion body 31, the cushion body 31 itself and the ceramic beef 9 are effectively cooled, so that high-temperature combustion of Yoshi JΔ becomes possible.

In the above embodiment, the combustor of a gas turbine has been described, but the present invention can also be applied to other combustors.

As explained above, according to the present invention, there is an effect that a combustor that is capable of high-temperature combustion and has high P mechanical strength can be obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a conventional combustor, FIG. 2 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 3 is a sectional view taken along line 3-3 in FIG. Fig. 4 is a vertical sectional view showing the main parts of Fig. 3, Fig. 5 is an exploded perspective view showing the assembly procedure of the segments, Fig. 6 is a side view showing the assembled segments, and Fig. 7 is a cement assembly. A side view showing a modified example of the means for attaching F to the inner cylinder, and FIGS. 8 and 9 are perspective views showing modified examples of the segment. 11... Combustion chamber, Minister... Combustion chamber wall (inner cylinder), 14.
...Cooling air, 15...Cooling air introduction hole, I...Fireproof wall, row...Segment, 4...Ceramic piece, J...Cover, 31...Cushion body, 32...
- Ceramic surface, cold 1J air introduction path. Patent applicant: Director of the Agency of Industrial Science and Technology (Figure 3, Figure 4, 82-Figure 6)

Claims (1)

[Claims] (1) A segment consisting of a plate-shaped ceramic piece, a cover that holds the ceramic piece, and a cushion body made of an elastic material interposed between the cover and the ceramic piece. A combustor having a ceramic fireproof wall structure, characterized in that a large number of the above-mentioned segments are attached to the inner surface of a combustion chamber wall with their ceramic surfaces facing inside, and these segments form a fireproof wall. (support)) Cooling air inlet holes are provided in the combustion chamber wall to introduce cooling air from the outside of the combustion chamber wall to the ceramic surface inside the segment, forming a film of cooling air on this ceramic surface. A combustor having a ceramic refractory wall structure according to claim 1. (3) The cushion body has air permeability and is provided with a cooling air introduction path for introducing cooling air into the cushion body from the outside of the heat-burning chamber wall. Combustor with ceramic firewall structure.