JPS63194127A - Heat insulation structure for liner of combustion apparatus - Google Patents

Abstract

PURPOSE:To facilitate the inclusion of a ceramic block, simplify the assembly and reduce the manufacturing cost by forming a support block having support grooves with shape memory alloy and loosely fitting the legs of a ceramic block into the support grooves. CONSTITUTION:A combustion apparatus 8 which burns the mixture of compressed air and fuel is installed in the liner inner tube 6 which is fastened by fastening screws 12 etc. Support blocks 11 extend in the axial direction of a metallic tube 10, and the inner surface of the metallic tube 10 and support blocks 11 is formed in the manner being exposed to high temperature. The support block 11 has a wedge-shaped support groove 13 extending lengthwise and the leg 16 of a ceramic block 15 having a similarly shaped wedge is loosely inserted into the support groove 13. The ceramic block 15 covers the entire high temperature-exposed surface of the liner inner tube 6 from inside to insulate the heat to the high temperature-exposed surface to maintain the mechanical strength of the liner inner tube 6.

Description

Detailed Description of the Invention (Objective of the Invention) (Industrial Application Field) The present invention relates to a heat shielding structure for a combustor liner such as a ceramic gas turbine combustor, and more particularly to a liner tube provided in the combustor liner. relating to a heat shielding structure.

(Prior Art) It is generally known that the turbine thermal efficiency of gas turbines used in gas turbine power plants is improved by increasing the turbine inlet temperature. In order to improve the turbine thermal efficiency, efforts are being made to increase the turbine inlet mm, and this increase in the turbine inlet temperature is achieved by increasing the outlet temperature of the gas turbine combustor. In order to increase the outlet temperature of the gas turbine combustor, it is desired to develop materials for the gas turbine combustor that have high strength, excellent heat resistance, and corrosion resistance in the high-temperature region.

Conventional gas turbine combustors have used heat-resistant superalloy materials, but in recent years ceramics, which have better heat resistance than heat-resistant superalloys, have been developed and are attracting attention. Ceramics are being used in various fields because they have high strength and high corrosion resistance in high-temperature regions, are lightweight, and have a small coefficient of wall expansion. Ceramics are suitable for structural members such as gas turbines, which are exposed to high-temperature corrosive environments and are subject to high stress. Because of this suitability, ceramics are used for walls that are exposed to high heat, such as the liner inner cylinder of gas turbine combustors, and the liner inner cylinder wall is covered from the inside with ceramic blocks to protect the liner inner cylinder wall from high temperatures. to maintain mechanical strength.

In that case, the ceramic block needs to be installed accurately in the liner inner cylinder of the gas turbine combustor with little play, but for this purpose the dimensions of the mounting groove formed in the liner inner cylinder and the mounting legs of the ceramic block must be Accuracy must be strictly controlled.

However, in reality, it is difficult to satisfy the dimensional accuracy between the mounting legs of the ceramic block and the mounting groove of the liner inner cylinder, and it is sometimes impossible to fit the ceramic block into the mounting groove, or even if the ceramic block is inserted into the mounting groove. Large installation play often occurs.

Japanese Utility Model Application Publication No. 57-127162 discloses a ceramic gas turbine combustor in which a mounting groove is provided on the high heat exposed wall surface of a liner inner cylinder, and a ceramic block is fitted into the mounting groove.

(Problems to be Solved by the Invention) In conventional combustor liners such as gas turbine combustors, a specific ceramic block that can be fitted into a mounting groove formed on the exposed high-temperature a wall surface of the liner inner cylinder is used in combination with a large number of ceramic blocks. It was necessary to select and assemble from among them, and the assembly operation of ceramic blocks was extremely complicated and required a great deal of time and effort.

In addition, because there is a difference in thermal expansion coefficient between the metal body that makes up the liner inner cylinder and the ceramic block, even if they are fitted correctly, when heat is applied, the metal body, which has a larger coefficient of thermal expansion than the ceramic block, will heat up. Ceramic blocks are subject to stress constraints due to looseness in the installation due to expansion, and differences in thermal expansion caused by thermal cycles such as when the gas turbine starts and stops, resulting in a state where the ceramic block is firmly fixed and cannot move. Therefore, there was a risk of damage.

The present invention has been made in consideration of the above-mentioned circumstances, and is a combustor that simplifies the assembly of the ceramic block that covers the wall surface of the liner cylinder and effectively prevents the occurrence of looseness in the installation due to differences in thermal flux. The purpose is to provide a heat shielding structure for the liner.

[Structure of the invention]

(Means for Solving the Problems) A heat shielding structure for a combustor liner according to the present invention defines a combustion chamber within a liner tube of the combustor liner, and the liner tube has a support groove in a wall surface exposed to high heat. A support block having a support groove formed therein, in which a mounting leg of a ceramic block is inserted into the support groove, and the wall surface exposed to high heat is covered with a ceramic block to thermally protect the burner liner. is molded from a shape memory alloy, and the mounting legs of the ceramic block are loosely fitted into the support grooves of the support block, and the support grooves recover their shape at high temperatures to grip the mounting legs.

(Function) This combustor liner has a support block formed with a support groove made of shape memory alloy, and a mounting leg of a ceramic block is loosely fitted into the support groove, and at high temperatures, the support groove recovers its shape and the mounting leg is Shape memory processing is applied so that it can be grasped.
The wall surface of the liner tube exposed to high heat is covered with a ceramic block to thermally protect the liner tube.

At that time, the support block in which the support groove was formed was molded from a shape memory alloy, and was treated with shape memory so that it would recover its shape at high temperatures.When the support groove was expanded at low temperatures, the mounting legs of the ceramic block could be attached to the support groove. Easy and simple to insert and install. Further, when the combustor liner is heated during operation, the support groove recovers its shape and grips the mounting leg, so that it is possible to effectively prevent the occurrence of play in the mounting of the ceramic block.

(Example) Hereinafter, an example of a heat shielding structure for a combustor liner according to the present invention will be described with reference to the accompanying drawings.

FIG. 2 shows a gas turbine 1 installed in a gas turbine power generation plant, and a compressor 2 for compressing combustion air is provided coaxially with the gas turbine 1. Compressed air discharged from the compressor 2 is guided to a plurality of ceramic gas turbine combustors 3, where it is mixed with fuel and combusted.

The gas turbine combustor 3 is installed facing the turbine inlet side of the gas turbine 1, and the combustion gas combusted in the gas turbine combustor 3 is guided to the gas turbine 1 via the transition piece 4, and this gas is Work is done by driving turbine 1.

In the gas turbine combustor 3, the combustor liner has a double-tube structure consisting of a liner outer cylinder 5 and a liner inner cylinder 6, and an air flow path 7 for guiding discharge air from the compressed n2 is formed therebetween. A combustor 8 is defined in the liner inner cylinder 6 to combust a mixture of compressed air and fuel.

The liner inner cylinder 6 is constructed as shown in FIGS. 1 and 3, and a plurality of support blocks 11, 11, . It is fixed by a fixing screw 12 or the like. The support block 11 extends in the axial direction of the metal tube 10, and the inner surface of the metal tube 10 and each support block 11 is formed as a wall surface exposed to high heat.

The support block 11 is made of a shape memory alloy and has a cross section shaped like a letter. A wedge-shaped support groove 13 extending in the longitudinal direction is formed in the support block 11, and a mounting leg 16 of a ceramic block 15 having a corresponding wedge shape is loosely fitted into the support groove 13.

The ceramic block 15 covers the entire wall surface of the liner inner cylinder 6 exposed to high heat from the inside, and maintains the mechanical strength of the liner inner cylinder 6 by blocking heat transmitted to the high heat exposed wall surface.

The ceramic block 15 is formed into a T-shape, and the curved wall defining the combustion chamber 8 and the mounting leg 16 are integrally formed. A heat insulating material 18 is filled between the ceramic block 15 and the metal tube 10 to block heat transmitted to the metal tube 10.

At this time, the heat insulating material 18 may be formed into a band shape and inserted between the metal tube 10 and the support block 11, so that the inner surface of the metal tube 10 is covered with the heat insulating material.

On the other hand, the support block 11 is formed of, for example, a Ni-Ti-based shape memory alloy, and the entire support block 11 is heated at a high temperature of, for example, 300° C. for one hour to perform shape memory treatment of the support grooves 13. The shape memory treated support groove 13 is formed so that its width is slightly narrower than that of the mounting leg 16 of the ceramic block 15.

Since it is impossible to insert the mounting legs 16 of the ceramic block 15 into the support groove shape of the support block 11 as it is, the support block 11 is heated to shape memory, then quenched to room temperature, and the support grooves 13 are expanded. The width dimension of the block 15 (which is slightly wider than the dimension of the mounting leg 16) is plastically worked.

When the support block 11 in which the support grooves 13 are expanded is heated at a high temperature of, for example, 500° C. for 1 minute, the support grooves 13 are expanded.
3 is restored to the memorized shape. As a result, both side walls of the support groove 13 contract inward, press and grip the mounting legs 16 of the ceramic block 15, and firmly support them. The support groove 13 has a shape similar to that of the mounting leg 16, and its shape is memorized so that the width of the groove is slightly smaller than that of the mounting leg 16 in order to evenly grip the mounting leg 16 when the temperature becomes high.

Note that the stress applied to the mounting leg 16 due to contraction of the support block itself when the support groove 13 recovers its shape is greater than the yield strength of ceramics at approximately 500°C. As a result, the support grooves 13 of the support block 11 are deformed to a state close to the original memorized shape during shape recovery. As long as this deformation can be obtained, the support block 11 is not limited to the Ni-Ti-based material, and may be made of other shape memory alloy materials.

Next, the operation of the gas turbine combustor will be explained.

Compressed air discharged from the compressor 2 is guided through an annular air passage 7 between an outer liner cylinder 5 and an inner liner cylinder 6.

is mixed with fuel on the way and guided to the combustion chamber 8,
be burned. Combustion gas from the combustion is introduced into the gas turbine 1 from the combustion chamber 8 through the transition piece 4, and drives the gas turbine 1 to perform work.

At that time, due to the operation of the gas turbine combustor 3, combustion v8
The air-fuel mixture is combusted within the combustion chamber 8, and the combustion chamber 8 becomes hot.

However, in this gas turbine combustor 3, the mounting legs 16 of the ceramic block 15 are supported by fitting into the support grooves 13 of the support block 11 made of a shape memory alloy. 11 is deformed, and as shown in FIG. 4, the support groove 13 is restored to its shape-memory-treated shape. Due to the restoration of the shape of the support groove 13, the mounting legs 16 of the ceramic block 15 are gripped from both sides and are closely supported by the groove side wall surfaces of the support groove 13.

Therefore, when assembling the liner inner cylinder 0, it is extremely easy to assemble the ceramic block 15 into the support groove 13 as shown in FIG. 5, and since dimensional accuracy is not required, the manufacturing cost is reduced.

In addition, since the support groove 13 of the support block 11 is molded from a shape memory alloy, the support groove does not enlarge due to thermal expansion unlike in the past, and the ceramic block does not increase due to stress due to mounting play or thermal expansion difference due to temperature cycles. There is no risk of damage.

In addition, in one embodiment of the present invention, a combustor liner applied to a gas turbine combustor was described, but this combustor liner can be used in a general combustor as long as the exposed wall surface is covered with ceramics. It is also possible to apply to

(Effects of the Invention) As described above, in the heat shielding structure for a combustor liner according to the present invention, the support block in which the support groove is formed is formed of a shape memory alloy, and the support groove of the support block is formed with a ceramic block. Since it is only necessary to make the mounting legs in the I shape, it is extremely easy to assemble the ceramic block, simplifying the assembly of the ceramic block, and dimensional accuracy is not required for the support groove and the ceramic block.
Production cost is low.

In addition, the support groove of the support block recovers its shape at high temperatures and grips and fixes the mounting legs of the ceramic block from both sides, ensuring stable fixation of the ceramic block and eliminating looseness in the installation of the ceramic block caused by differences in thermal expansion. The occurrence of this can be effectively and reliably prevented, and the life of the ceramic block can be extended.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view showing an embodiment of a heat shielding structure for a combustor liner according to the present invention, and FIG. 2 is a diagram showing a gas turbine power generation plant equipped with a gas turbine combustor of the above-mentioned combustor liner. , Fig. 3 is a partial view showing the inner cylinder wall surface of the combustor liner with a part of the ceramic block removed, Fig. 4 is an enlarged sectional view taken along the line ■-IV in Fig. 3, and Fig. 5 is a high-temperature operating state. 1. This is an enlarged cross-sectional view similar to FIG.
... Gas turbine, 2... Compressor, 3... Gas turbine combustor, 5... Liner outer cylinder, 6... Liner inner cylinder (liner cylinder), 7... Air flow path, 8 ... Combustion chamber, 1
0...Metal tube, 11...Support block, 13...
Support groove, 15...Ceramics block, 16...
Mounting leg, 18...Insulation material. Figure 1 Figure 3 Figure 2

Claims (1)

[Claims] 1. A combustion chamber is defined in the liner cylinder of the combustor liner, and the liner cylinder has a support groove formed on the wall surface exposed to high heat, and the mounting leg of the ceramic block is inserted into the support groove. In the heat shielding structure of a combustor liner in which the wall surface exposed to high heat is thermally protected by covering the wall surface with a ceramic block, the support block in which the support groove is formed is molded from a shape memory alloy,
A heat shielding structure for a combustor liner, characterized in that the mounting leg of the ceramic block is loosely fitted into the support groove of the support block, and the support groove recovers its shape and grips the mounting leg at high temperatures. 2. The combustor liner according to claim 1, wherein the support block extends in the axial direction on the inner peripheral surface of the metal cylinder of the liner cylinder, and a heat insulating material is filled between the metal cylinder and the ceramic block. heat shield structure. 3. The support block has a U-shaped cross-sectional shape, and the support groove of the support block and the mounting leg of the ceramic block are formed in a wedge shape that can be fitted into each other. Thermal shielding structure of the combustor liner described. 4. The support groove of the support block is subjected to shape memory treatment so that the width of the groove becomes slightly smaller than that of the mounting leg when the shape is restored at high temperatures.
The heat shielding structure for a combustor liner according to claim 1, wherein the width of the support groove is expanded at low temperatures.