JPH02233908A - Combustion chamber and its cooling method - Google Patents

Abstract

PURPOSE:To reduce thermal stresses generated in heat resisting tiles and improve heat resisting performance by a method wherein a heat resisting member is composed of frame resisting cloth formed by flame resisting fiber and heat resisting tiles formed by heat resisting material and the heat resisting tiles are fixed inside through the flame resisting cloth. CONSTITUTION:In a combustion chamber which includes a heat resisting member and a metal cylinder 21 on the inside of which the heat resisting member is fixed, being equipped with flowing systems of combustion air and cooling air respectively, the heat resisting member is formed by flame resisting cloth 22 and heat resisting tiles 23 and cooling air is introduced through cooling air holes 25 drilled on the cylinder 21 and caused to flow through the textures of the cloth 22 and the structure of air flow is so constituted as to exude the cooling air into the inside of the tiles through the circumferences, boundaries of the tiles 23, or the holes 25 drilled on the tiles. The length of one side of the title is less than that of one fourth of the circumference of the metal inner cylinder and the heat resisting tiles are formed by sintered body or ceramic combined material mingled with ceramic fiber and a number of holes are drilled on the tiles 23 or the tiles are formed in a honeycomb shape. Then, the tiles are fixed on the cylinder 21 with heat resisting bolts 24.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention improves the heat resistance of a combustor liner and tailings in a gas turbine, improves the cooling performance of the combustor wall surface temperature,
The present invention also relates to a combustor suitable for reducing cooling air for the combustor and a method for cooling the same.

[Conventional technology]

In conventional combustors, as described in JP-A-59-15727 and JP-A-62-5021,
In the former, a ceramic tile is provided on the inner circumference and a metal tube is provided on the outer circumference, and the tile is fixedly supported by a fixing device made of ceramic or the like on the metal tube at all or part of the outermost edge of the tile. ．． On the other hand, the latter had a structure in which the innermost periphery of the combustor was formed by a combustion tube made of ceramic fiber, and the combustion tube was fixedly supported by a metal surrounding wall placed around the outer periphery. In the tile method, thermal stress occurs on the ceramic tile due to the fixed support of the tile, and the thermal environment around the ceramic tile is not appropriate, so the surface on the combustion gas side of the tile is heated by the combustion gas, while the back surface is heated. Not enough consideration was given to the thermal load on the tiles that were cooled by the cooling air, and there was a problem of reduced strength reliability due to thermal stress generated in the tiles. In other words, ceramic tiles are heated and cooled on the front and back surfaces, and not only does thermal stress occur in the thickness direction, but also the fixing support part of the tile is cooled on the contact surface due to contact with the fixing support. A large temperature gradient occurs within the tile surface, and thermal stress is induced due to this. In addition, since the contact with the relatively low-temperature fixing support is located at the outer periphery of the tile, the center of the entire tile is hot and the periphery is relatively cold, resulting in heat generated by thermal deformation inside the tile. It is possible that stress is generated. The fiber combustion tube system attempts to obtain high heat resistance and reliability by using ceramic woven fabric instead of the ceramic tiles.

In this method, since the combustion gas comes into direct contact with the fiber combustion tube, the cooling air is allowed to seep slightly into the combustion tube through minute gaps in the woven ceramic fiber cloth to cool the combustion tube, and the combustion gas The structure is designed to prevent water from flowing into the walls of the combustion chamber. However, in this conventional technology, cooling air uniformly flows into the textile combustion chamber, and if sufficient cooling is not always achieved through seepage, the heat-resistant woven fabric on the innermost side, which is directly exposed to combustion gas, may partially However, there was a problem in that it was heated above its heat-resistant temperature and immediately suffered damage due to oxidative deterioration, etc. In the tile system shown in FIG. 16, a ceramic tile 4 of an appropriate size is fixed to a metal frame 2 by a holder 3 and a push rod 9. At this time, the ceramic tile 4 has a relatively thick flat plate shape as shown in FIG. 17, and is fixedly supported by the holder 3 at the groove portion 4b. Changes occur and the generation of large thermal stress is unavoidable. 18 to 21 show a structure made of a heat-resistant fiber tube, the fiber tube 11 is provided with combustion air holes 13, and the metal tube 12 is also provided with air inlet holes 13 at the same position. ing. This fiber tube 11 is fixedly supported by a metal tube 12 with bolts or the like (not shown). Since the fiber tube 11 is directly exposed to the combustion gas flow 16, cooling air 17 introduced from a large number of cooling air holes 14 provided in the metal tube 12 is directed in the thickness direction of the fiber tube 11, as shown in the figure. The fiber cylinder 11 is cooled and the combustion gas flow inside the cylinder is prevented from flowing out of the cylinder. This fiber tube 11 is made by winding (or overlapping) a large number of fabrics made of heat-resistant ceramic fibers Y3. However, if this cooling air 17 is insufficient, the ceramic fibers on the innermost circumferential side of the fabric forming the fiber cylinder 11 will be exposed to high temperatures, causing problems such as oxidation or deterioration and damage. was occurring.

[Problem to be solved by the invention]

In the conventional combustor and its cooling method, the tile method generates thermal stress not only in the thickness direction of the tile, but also between the center and the periphery, which causes thermal stress. The problem with the cylinder method was that the combustion cylinder was not cooled uniformly, causing local heating and oxidation, leading to deterioration and damage. The purpose of the present invention is to reduce the thermal stress generated in heat-resistant tiles made of heat-resistant materials, and to improve heat-resistant performance and strength reliability that can prevent partial oxidation and deterioration of heat-resistant woven fabrics made of heat-resistant fibers. An object of the present invention is to provide a combustor and a method for cooling the same.

[Means to solve the problem]

In order to achieve the above object, the combustor according to the present invention has a heat-resistant member fixed to the inner surface of a metal tube, and a combustion air and cooling air circulation means in each of the heat-resistant member and the metal tube. The heat-resistant member includes a heat-resistant woven fabric made of heat-resistant fibers and a heat-resistant tile made of a heat-resistant material, and the heat-resistant tile is fixed to the inner surface via the heat-resistant woven fabric.

Further, one side of the heat-resistant tile is formed to be equal to or less than the length obtained by dividing the circumference of the metal inner cylinder into four.

Furthermore, the heat-resistant tile is made of a ceramic sintered body or a ceramic composite material containing ceramic fiber, and the heat-resistant tile is made of a ceramic sintered body or a ceramic composite material containing ceramic fiber. A large number of holes shall be bored in the tiles or the heat-resistant tiles shall be formed into a honeycomb shape.

The heat-resistant tiles are fixed to the metal tube with heat-resistant bolts.

In addition, in a method for cooling a combustor in which a heat-resistant member is fixed to the inner surface of a metal cylinder, and each of the heat-resistant member and the metal cylinder is provided with a means of circulating combustion air and cooling air, the heat-resistant member is made of heat-resistant woven fabric and heat-resistant tiles. The cooling air is introduced through the cooling air holes formed and drilled in the metal cylinder, the cooling air is distributed through the weave of the heat-resistant woven fabric, and the cooling air is formed around, at the border of, or drilled in the heat-resistant tile. It is configured to exude cooling air through the holes and onto the inner surface of the refractory tile.

[Effect]

According to the present invention, by fixing the heat-resistant tile to the inner surface of the metal cylinder of the combustor via the heat-resistant woven fabric, the heat-resistant woven fabric is not directly exposed to combustion gas.

The cooling air that flows in through the cooling air holes in the metal cylinder flows uniformly within the heat-resistant fabric, and seeps out from around the heat-resistant tile to its inner surface. On the other hand, relatively brittle heat-resistant tiles are fixed to the metal fittings using a heat-resistant woven fabric as a cushion, which alleviates the mechanical force during fixation and absorbs thermal deformation of the heat-resistant tiles, thereby reducing the overall combustion rate of the combustor. Vibration is also damped.

〔Example〕

An embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, in a combustor in which a heat member is fixed to the inner surface of a metal tube 21, and each of the heat-resistant member and the metal tube 21 is provided with a circulation means for combustion air and cooling air, the heat-resistant member is The heat-resistant tile 23 is made up of a heat-resistant woven fabric 22 made of heat-resistant fibers and a heat-resistant tile 23 made of a heat-resistant material.
is fixed to the inner surface via a heat-resistant woven fabric 22.

In the embodiment shown in FIG.
2 is pressed and fixed to the metal tube 21 by heat-resistant tiles 23 and connectors 24 made of heat-resistant bolts. FIG. 2 shows a conceptual diagram of a part of the combustor according to the present invention. In this embodiment, the heat-resistant tiles 23 are hexagonal tiles. Although not mentioned in detail in the present invention, the combustor requires a combustion air inlet 25, and the combustion air inlet 25 is connected to the heat-resistant tile 23.
It can be formed by cutting out a part of the. A specific example of the heat-resistant tile is shown in Figures 4 and 5. A hexagonal heat-resistant tile 23 is provided with a large number of holes 26 or formed into a honeycomb shape.

Of course, the arrangement of the holes 26 can be selected in various ways.
Another embodiment is shown in FIGS. 7 and 8bi.

The heat-resistant tile 23 forms part of a cylindrical shape, and has a rectangular shape as a whole. Heat-resistant tiles 23 in Figures 4 to 8
A fixing hole 27 provided approximately in the center is for fixing the heat-resistant tile 23 to the metal cylinder 21 via a fixture 24. This situation is specifically shown in FIG. The heat-resistant woven fabric 22 is pressed and fixed to the metal tube 21 by a connector 24 via a heat-resistant tile 23. Cooling air holes 30 provided in the metal cylinder 21 are for taking in cooling air.

Figure 10 shows an example of the shape of the heat-resistant tile in the combustion air inlet 25 section. One side of the heat-resistant tile 23 is formed to have a length obtained by dividing at least the circumference into four, four tiles are arranged at the four corners, and an inner hole, that is, a combustion air inflow hole 25 is formed in the center part. FIG. 12 shows another example of the arrangement of heat-resistant tiles, metal inner tubes, and heat-resistant woven fabrics on the combustor wall. 9th
Unlike the embodiment shown in the figure, a metal cylinder 21 and a heat-resistant woven fabric 2
A metal inner cylinder 28 is further arranged between the inner cylinder 28 and the metal cylinder 21, and a gap 29 is provided between the inner cylinder 28 and the metal cylinder 21. Cooling air introduced through the cooling air hole 30 opened in the metal tube 21 is first guided to the air gap 29 and then passed through the metal inner tube 28.
It reaches the heat-resistant woven fabric 22 through a large number of small holes 31 provided in the heat-resistant tile, and is then released into the combustion gas flow 32 through the holes 26 provided in the heat-resistant tile and the gaps between adjacent heat-resistant tiles 23.

Another embodiment is shown in FIG. Unlike the embodiment shown in FIG. 12, the heat-resistant tiles 23 are not provided with cooling air holes, and the structure is such that the cooling air is exclusively released into the combustion gas flow 32 through the gaps 33 between adjacent heat-resistant tiles 23. Another embodiment is shown in FIG. 14. In this embodiment, the cooling air flowing in from the cooling air hole 30 of the metal tube 21 is guided to the air gap 29, and then the cooling air flows through the small hole 31 of the metal inner tube 28. It flows between the textures of the heat-resistant woven fabric 22 and reaches the space 34 provided in the heat-resistant tile 23 . The cooling air filling the space 34 is then released into the combustion gas flow 32 through the gap 33. An overview of the heat-resistant tile 23 is shown in FIG.

The present invention is based on the advantages of the tile method and the fiber combustion tube method, namely, in the tile method, ceramic tiles (heat-resistant tiles) with excellent heat resistance are placed in the parts that are directly exposed to combustion gas; The cylindrical method takes advantage of the fact that ceramic fibers (heat-resistant fibers), which have excellent breaking strength against thermal deformation, play a major role, and further reduces the thermal stress generated in the ceramic tiles and prevents deterioration due to oxidation of the ceramic fibers. In order to do this, a heat-resistant inorganic material (for example, a ceramic combustion body or a ceramic fiber composite material) is used as the innermost member of the combustor that is directly exposed to combustion gas, and a heat-resistant woven fabric made of heat-resistant fibers is placed around the outer circumference of the material. It has a structure in which a heat-resistant inorganic material is flexibly fixed and supported, and the entire structure is supported by a metal tube provided on the outermost periphery.

Furthermore, in order to guarantee the heat resistance of the heat-resistant fibers, cooling air is passed through the weaves of the heat-resistant woven fabric.

In addition, a large number of holes are provided in the member made of heat-resistant inorganic material that is directly exposed to combustion gas to reduce the thermal stress, and the temperature of the member is made uniform, and the heat-resistant woven fabric made of heat-resistant fibers is This allows the circulating cooling air to be released into the combustion gas flow without stagnation. In addition, regarding strength reliability, since the stress generated in heat-resistant tiles is basically thermal stress, with a perforated plate (or honeycomb), the generated thermal strain is released by the effect of the holes, making it possible to reduce thermal stress. Even heat-resistant tiles made of heat-resistant materials are substantially more reliable. Furthermore, with perforated plates (or honeycombs), if a crack occurs in a part of the heat-resistant tile, the crack will not only propagate and stop when it reaches the hole, but will also release thermal strain energy. It has the effect of [Effects of the Invention] According to the present invention, heat-resistant tiles are fixed to the inner surface of the combustor via a heat-resistant woven fabric, and cooling air is distributed through the heat-resistant woven fabric, thereby improving heat resistance performance and significantly reducing the amount of cooling air. can. As a result, the utilization rate of combustion air increases, which is advantageous when using coal gasified fuel. Improving heat resistance enables high-load combustion, and has the secondary effect of freely reducing NOx.

Furthermore, since the heat-resistant tile is formed into a porous shape, the stress is alleviated, and even if a crack occurs, it has the effect of stopping the crack.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIGS.
The figure shows an example of the heat-resistant tile in Figure 1, Figure 5 is a sectional view of ■ and ■ in Figure 4, and Figure 6 is a partially enlarged view of Figure 4.
Figures 7 and 8 are diagrams showing other embodiments of heat-resistant tiles;
FIG. 9 is a partial sectional view showing another embodiment of the present invention, and FIG.
11 and 11 are views showing other embodiments of the heat-resistant tile, FIGS. 12 to 14 are partial sectional views showing other embodiments of the present invention, and FIG. 15 is another embodiment of the heat-resistant tile. A perspective view showing
Fig. 16 is a plan sectional view showing the conventional technique, Fig. 17 is a perspective view showing a ceramic tile of the conventional technique, Fig. 18 is a vertical sectional view showing the conventional technique, and Figs. FIG. 18 is a plan sectional view, and FIG. 21 is a perspective view of the conventional technology. 21...Metal tube, 22...Heat-resistant woven fabric, 23...
・Heat-resistant tile, 25... Intake air hole (combustion air hole).

Claims (1)

[Claims] 1. In a combustor in which a heat-resistant member is fixed to the inner surface of a metal cylinder, and each of the heat-resistant member and the metal cylinder is provided with a means for circulating combustion air and cooling air, the heat-resistant member is a heat-resistant member. A combustor comprising a heat-resistant woven fabric made of fibers and a heat-resistant tile made of a heat-resistant material, the heat-resistant tile being fixed to the inner surface via the heat-resistant woven fabric. 2. Claim 1, characterized in that a metal inner cylinder is provided on the outer periphery of the heat-resistant woven fabric, and a gap is provided between the outer periphery of the metal inner cylinder, which has a large number of small holes, and the inner periphery of the metal cylinder. Combustor as described. 3. The combustor according to claim 1 or 2, wherein one side of the heat-resistant tile is formed to be equal to or less than a length obtained by dividing the circumference of the metal inner cylinder into four. 4. The combustor according to claim 1, 2 or 3, wherein the heat-resistant tile is formed of a ceramic sintered body or a ceramic composite material containing ceramic fibers. 5. Claims 1, 2, and 3, characterized in that the heat-resistant tile has a large number of holes or is formed into a honeycomb shape.
Or the combustor described in 4. 6. The combustor according to claim 1, 2, 3, or 4, wherein the heat-resistant tile is fixed to the metal cylinder by heat-resistant bolts. 7. A method for cooling a combustor, in which a heat-resistant member is fixed to the inner surface of a metal tube, and each of the heat-resistant member and the metal tube is provided with circulation means for combustion air and cooling air, in which the heat-resistant member is fixed to a heat-resistant woven fabric and a heat-resistant Cooling air is introduced through cooling air holes formed in the metal cylinder, and the cooling air is circulated through the weave of the heat-resistant woven fabric, and the cooling air is passed through the weave of the heat-resistant woven fabric, and is formed around the heat-resistant tile, at its boundary, or around the heat-resistant tile. A method for cooling a combustor, comprising causing the cooling air to seep out onto the inner surface of the heat-resistant tile through cooling air holes formed in the heat-resistant tile.