JPH087246Y2 - Assembly structure of ceramic combustor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a combustor of a gas turbine, and more particularly to an improvement of an assembly structure of a ceramic combustor.

[Conventional technology]

In a gas turbine, a combustor is an important part that combusts a fuel supplied from the outside and generates a high-temperature high-pressure combustion gas that drives a compressor turbine and an output turbine. In the past, it was common to use refractory metals as the material for combustors, but recently there has been a tendency to raise the temperature of combustion gas more than before to improve the efficiency of gas turbines. In manufacturing, the heat resistance is insufficient, and ceramic materials are being used. Further, in order to reduce the thermal stress at high temperature and to facilitate maintenance work, the combustor is not made into an integral structure but divided into several parts to have an assembled structure.

However, the ceramic material is brittle, and if there is a stress concentration part, cracks are likely to occur in that part, and the method of tightening and fixing with a bolt, nut, etc. cannot be used for assembling the above ceramic combustor, and stress concentration is avoided. It was necessary to use the appropriate method.

For this purpose, the members composing the ceramic combustor are fitted with each other with a certain amount of play. For example, Japanese Utility Model Laid-Open No. 57-30569 discloses a ceramic combustor having a cylindrical portion. Is integrally formed, and a swirler is fitted into the tubular portion, and is clamped from the outside with a metal holding plate or band.

In addition, in order to prevent backlash and vibration due to play between the members at the fitting portion, one fitting member is biased by a spring against the other member, and elastic force is applied to prevent stress concentration. A method of absorbing play has been devised. For example, in Japanese Patent Laid-Open No. 57-84930, a ceramic combustor liner is externally spring-biased via a rod so that the space between the combustor liner and the engine block is increased. Japanese Patent Application Laid-Open No. 57-14127 describes a structure in which a combustor is elastically pressed and supported toward a scroll portion by an arm urged by a spring.

Further, JP-A-57-74528 discloses that ceramic combustors divided by a plane perpendicular to the axial direction are fitted to each other at their ends,
A configuration is described in which both members are fixed with a resilient clamp.

[Problems to be solved by the device]

In the above-mentioned known technology, the structure of the combustor assembling portion is complicated in the structure in which the spring means attached to the outside of the combustor via the arm and the rod presses and holds the combustor structure. There were problems such as an increase in the number of man-hours for assembly and maintenance work. Further, the structure in which the connecting portion of the combustor portion is elastically fixed by using the clamp is directly exposed to the heat of the combustor, and therefore, when a metal material is used for the clamp,
A decrease in elasticity due to high temperature (so-called "fatigue") occurs,
There was a possibility that the clamp would loosen and loosen the connection. Further, a ceramic material having excellent heat resistance has a problem in formability, and cannot be used for the purpose of bending and mounting a plurality of pieces like the above clamp, and the structure using the above metal clamp also has a problem in reliability. .

An object of the present invention is to solve the above problems and to provide a simple and reliable assembly structure in which members of a ceramic combustor are elastically fixed to each other by using leaf springs of a simple shape that can be formed of a ceramic material. There is.

[Means for Solving the Problems] According to the present invention, in the assembly structure in which the end portions of the respective divided portions of the ceramic combustor are fitted together, the fitting of the respective divided portions of the fitting portion is performed. An assembly structure in which a plurality of grooves facing each other are arranged on the peripheral surface of the fitting portion, a leaf spring is housed in the groove, and the above members are elastically held by the reaction force of the leaf spring. Will be provided.

The leaf spring has a simple flat U-shape that can be formed of a ceramic material, and one of the grooves of the fitting surface has a concave shape having a bottom surface that engages with the U-shaped bottom portion of the leaf spring. The movement of the spring in the circumferential direction and the axial direction is restricted, the other groove is longer than the one groove, and an end of the groove facing the one groove engages with both ends of the leaf spring when member assembly is completed. An engaging part with a shallow groove depth is formed, the other end opens toward the member shaft edge, and forms an introduction part through which the leaf spring can pass when assembling the member. Is shallower from the introduction side end toward the locking side end.

[Action]

At the time of assembly, a leaf spring is mounted in the recessed groove of one component of the ceramic combustor, and the axial position of the groove of the other component is aligned with each other, whereby the components can be fitted in the axial direction. . Further, by rotating both parts relatively after fitting, the leaf spring moves from the introduction portion of one groove to the locking portion, and the U-shaped bottom portion of the one leaf spring is engaged with the one locking groove. Are held together, so that the interfitting parts are prevented from axially constraining each other and disengaging.
Further, the leaf spring engaged with the locking portion generates a force that separates both components in the radial direction, and both components are elastically held in a state without play.

〔Example〕

 FIG. 6 shows the structure of the main part of the gas turbine engine.

In the figure, the air 21 sucked from the atmosphere through a filter (not shown) increases in pressure while passing through the compressor impeller 22, the diffuser 23, and the scroll 24, and heat is recovered from the exhaust gas by a heat exchanger (not shown) to raise the temperature. It becomes high-pressure air 25 and flows into the combustor 1. In the present embodiment, the combustor 1 is composed of three parts made of ceramics, a swirl part 2, a combustor 3, and a dilution part 4.
Then, the inflowing air is supplied with a swirling speed, is mixed with the fuel injected from the fuel nozzle 26, and is further combusted by the combustion air flowing into the combustion part 3 to become a high-temperature and high-pressure combustion gas, which then flows into the dilution part 4. . In the dilution section 4, the combustion gas mixes with the diluted air flowing in from the surroundings to form a large amount of high-temperature gas, which then flows into the turbine scroll section 27 and enters the compressor turbine.
28, and further drives a power turbine (not shown) to pass through the heat exchanger and then is discharged to the atmosphere.

The present invention relates to a simple and reliable improved assembly structure in which the swirl portion 2, the combustion portion 3, and the dilution portion 4 of the combustor 1 are connected to each other to form the combustor 1.

The structure of the combustor 1 is shown in FIG. The combustor 1 comprises a swirl section 2, a combustion section 3, and a dilution section 4 which are ceramic parts, and the combustion section 3 and the dilution section 4 are substantially cylindrical in shape.
The swirl part 2 forms a cover for covering the upper part of the combustion part 3,
A through hole for inserting the fuel nozzle is provided in the central portion. Further, an air introduction hole for forming a swirling flow is provided in the upper part of the swirl portion, and combustion air and dilution air introduction holes are provided around the combustion portion 3 and the dilution portion 4, respectively. As shown in the figure, the above three parts are assembled by fitting the ends to each other to form one combustor. This fitting part is fitted with a certain amount of margin for the purpose of preventing stress due to thermal strain and the like from concentrating on the fitting part of each component.
The passage of the high-pressure combustion gas may cause the components to vibrate in the radial gap, resulting in backlash. In order to prevent this, the fitting portion has a structure described below.

 2 to 6 show details of the fitting portion structure.

The fitting portion between the swirl portion 2 and the combustion portion 3 will be described below. The outer circumference 10 of the combustion portion and the inner circumference 11 of the swirl portion of the fitting portion are opposed to each other at a plurality of locations (three locations in this embodiment) on the circumference. A set of grooves 12 and 13 are arranged at a plurality of positions at equal intervals in the circumferential direction, a leaf spring molded body 14 made of ceramic is housed in the groove, and a combustion part outer circumference 10 and a swirl part inner circumference 11 are The plate springs 14 are elastically held to each other. (FIGS. 2 and 3) The groove 13 of the inner circumference 11 of the swirl portion is matched with the shape of the leaf spring 14 as shown in FIGS. The groove depth is smaller than the free height of the leaf spring, and both ends of the leaf spring protrude from the groove 13 when the leaf spring is accommodated.

On the other hand, as shown in FIG. 4, the groove 12 of the outer periphery 10 of the combustion portion is extended in the circumferential direction longer than the entire length of the leaf spring 14, and at one end, the length of the leaf spring 14 can pass in the axial direction. An introduction portion 15 that is opened in the axial direction toward the outer peripheral end surface of the combustion portion and a subsequent deep groove portion are formed, and a sidewall 16 is formed at the other end so that the leaf spring 14 cannot move in the axial direction. It is a locking portion 17. As shown in FIG. 3, the depth of the groove 12 is close to the free height of the leaf spring 14 at the introduction portion 15, and at the engaging portion, when the groove 13 and the engaging portion 17 face each other when the assembly is completed, The leaf spring is shallow so as to generate an appropriate reaction force, and the groove depth between the introduction portion 15 and the locking portion 17 continuously changes.

As shown in FIG. 6, the leaf spring 14 has a flat U shape in which both ends of a flat plate are angled, and has a simple shape suitable for molding from a ceramic material by sintering. In the present invention, since the groove shape as described above is used, it is possible to use the ceramic material with the leaf spring having a simple shape as shown in FIG. Therefore, there is no problem of backlash between the swirl portion 2 and the combustion portion 3.

At the time of assembly, the leaf spring is temporarily fixed to the groove 13 by using an appropriate means such as an adhesive, and in this state, the position of the leaf spring 14 and the position of the introduction portion 15 of the groove 12 are aligned with each other to swirl. The combustion part 3 is inserted into the part 2 in the axial direction. At this time, the leaf spring 14
Is held between the groove 13 and the introduction part 15 of the groove 12,
Since 15 is deep enough, the leaf spring 14 does not hinder the insertion operation. After this inserting operation is completed, the combustion part 3 and the swirl part 2 are rotated mutually, and the groove 13 is moved to a position facing the locking part 17 of the groove 12. Groove 12 as described above
Since the depth of is shallow at the locking part 17, the leaf spring 14
It is compressed between the bottom part and the bottom part of the locking part 17 to generate an appropriate reaction force, which elastically holds the swirl part 2 and the combustor 3 in the radial direction. Further, the locking portion 17 of the groove 12 has the side wall and engages with the leaf spring leg portion, so that the swirler 2 and the combustor 3 are prevented from separating from each other in the axial direction. The movement of the leaf spring 14 from the introduction portion 15 of the groove 12 to the fixed portion 17 is smooth because the groove depth continuously changes from the introduction portion 15 and the deep portion following the introduction portion 15 to the locking portion 17. Done.

The fitting part between the swirl part 2 and the combustion part 3 has been described above, but the same applies to the fitting part between the combustion part 3 and the dilution part 4. Further, in the above-mentioned embodiment, the combustion part 3 is inserted into the inner diameter part of the swirler 2 and the dilution part 3, but it goes without saying that the present invention can be similarly applied to a structure in which either one is inserted inside.

[Effect of device]

With the above-described structure, the parts composing the ceramic combustor can be elastically held with a simple structure, and the number of parts can be significantly reduced as compared with the conventional method. Further, by adopting the above-mentioned structure, the leaf spring shape can be simplified into a U-shape, and a leaf spring using a ceramic material which could not be used in the past can be formed. Will be resolved. Further, since the leaf spring is housed inside the groove and is not exposed to the outside, there is no risk of damage due to contact with surrounding parts during assembly and disassembly work. Further, the assembling work only requires inserting the parts and rotating and fixing them, and the working man-hours are greatly reduced. Further, in the present invention, it is possible to prevent the component fitting portion from being disengaged in the axial direction, so that the reliability of the assembly structure is increased.

[Brief description of drawings]

FIG. 1 is a sectional view showing an assembly structure of a ceramic combustor of the present invention, FIG. 2 is a transverse sectional view showing a fitting portion of a combustion portion and a swirl portion, and FIG. 3 is a sectional view of FIG. Enlarged views of the groove portion, FIGS. 4 and 5 are perspective views showing the shape of the groove, FIG. 6 is a perspective view showing the shape of the leaf spring, and FIG. 7 is a view of a gas turbine engine using a ceramic combustor. Sectional view of the main part. 1 ... Combustor, 2 ... Swirl part, 3 ... Combustion part, 4 ...
… Diluting part, 12 …… Burning part, 13 …… Swirl groove, 14 ……
Leaf spring.

Claims (1)

[Scope of utility model registration request] 1. A split structure of a gas turbine, wherein an end portion of each split portion of a ceramic combustor is formed in a cylindrical shape, and the split end portions are connected to each other by connecting the split end portions to each other. On each of the fitting surfaces of the parts, a plurality of sets of opposed locking grooves are arranged at intervals in the circumferential direction, and both of the divided parts fitted in the sets of the locking grooves are elastically arranged. A leaf spring having a flat U-shaped cross section is arranged to be pressed and urged, and the first locking groove of each set has a maximum depth at a substantially central portion of a circumferential length thereof. The second locking groove of each set is formed in a recessed shape that engages with the character-shaped bottom portion, and is longer than the first locking groove so that the depth of the second locking groove becomes shallower as it faces the first locking groove. The second locking groove is formed in a shape, and the shallowed portion of the second locking groove forms a locking portion with which both ends of the leaf spring are engaged, and a second locking Is formed in the deep portion thereof at the axial end edge of the divided portion, and the leaf spring is introduced into the deep portion from the introduced portion at the time of connecting the divided portion, and further along the circumferential direction. An assembling structure of a ceramic combustor, characterized in that the second engaging groove can be moved to a stop.