JPS6124676Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of a flow path connecting a compressor turbine and a power turbine of a ceramic gas turbine.

FIG. 1 shows the upper half of the flow path of a conventional two-shaft ceramic gas turbine. It consists of a strut 6 that connects both 4 and 5.

In this way, the gas flow path 3 of the conventional two-shaft ceramic gas turbine has a structure in which the inner case 4, the outer case 5, and the strut 6 are integrated, and in some cases, only the upstream path portion is separated for convenience of assembly. It has an assembled structure, and both ends are connected to the compressor turbine 1.
There are also those that are firmly fixed to the power turbine 2 with pins or the like.

However, due to the high temperature gas flowing through flow path 3,
Each part of the flow path expands due to heat, but since it is impossible for all of the components that make up the flow path to experience a uniform rise in temperature, thermal stress is generated in each part, and such a conventional structure has the disadvantage that cracks are generated or the connecting pins are broken.

This idea was made in view of the above points,
The present invention aims to provide a gas flow path for a ceramic gas turbine that solves the conventional drawbacks by separating the outer case, inner case, and strut that constitute the gas flow path and elastically assembling them.

Hereinafter, an embodiment of this invention will be described with reference to FIGS. 2 to 4, and the same parts as in FIG.

2 and 3 show an embodiment of this invention, in which the gas flow path 13 that communicates the compressor turbine 1 and the power turbine 2 is connected to an inner case 14, an outer case 15, and an outer case 15, which are respectively made of separate parts. It has a divided structure consisting of a strut 16 that connects both to each other.

Cylindrical recesses 14a are provided at three or more locations on the same circumference of the inner case 14, and an annular protrusion 15b having a through hole 15a is formed in the outer case 15 opposite to the recess 14a.

On the other hand, the strut 16 has cylindrical portions 1 at both ends.
6a and 16b, a wing-shaped portion 16c is formed in the center, a groove 16d for a ring seal is provided on the side surface of the columnar portion 16a, and a plurality of grooves are provided on the center side (lower side in the figure) of the groove 16d. A circumferential groove 16e is provided to provide a labyrinth seal to reduce leakage.

This strut 16 is connected to the outer case 1.
5 through the through hole 15a of the inner case 14, and with the blade direction of the blade shaped part 16c facing the gas flow direction, the tip cylindrical part 16b is inserted into the recess 14a of the inner case 14.
After the ring seals 17 are fitted into the grooves 16d, each strut 16 is fitted with its elastic force.
is pressed toward the center.

In this way, the inner case 14, outer case 15, and strut 16 are elastically assembled and integrated by the ring seal 17, and the gas flow path 13
form.

Note that the strut 16 receives a force due to the differential pressure between the gas flow path 13 and the atmosphere, and this force becomes an inward or outward force depending on the installation position of the strut 16. If it is on the outside, there is no problem at all, but if it is on the inside, the strut 16 will come off, so it is necessary to apply tension to the ring seal 17 to resist that force.

Next, FIGS. 4a and 4b show examples of different shapes in which a part of the strut is changed.

In the structure shown in FIG. 4a, the strut 26 is formed from prismatic portions 26a and 26b at both ends and a central wing-shaped portion 26c, and a groove 26d for a ring seal and a plurality of grooves for labyrinth seals are formed on the side surface of the prismatic portion 26a. A corner circumferential groove 26e is provided to reduce the force applied to the strut 26 as much as possible when the pressure difference between the flow path and the atmosphere becomes a force acting from inside.

The strut 36 shown in FIG.
A groove 36d for a ring seal is provided on the end face of the columnar portion 36a, and a groove 36d for a ring seal is provided on the end surface of the columnar portion 36a.
A circumferential groove 36e for a labyrinth seal is provided on the side surface of a.

FIG. 5 shows the strut 36 shown in FIG. 4b.
Another example using . In this embodiment, the strut 36 is inserted between the inner case 14 and the outer case 15 in the same way as the strut 16 in FIG. A ring 38 is provided to hold the ring seal 37 by fitting it into the groove 38a from the outside.
This is to more completely prevent the outer part from leaving.

As described above, according to this invention, the gas flow path that communicates the compressor turbine and power turbine of a ceramic gas turbine is connected to the inner case and the outer case, and the strut that connects the inner case and the outer case to each other. Since the ring seal has a separate structure and is assembled using the elasticity of the ring seal, the thermal stress caused by the imbalance of temperature distribution in each part of the gas flow path is alleviated by the elasticity, preventing cracks and breakage of connecting members. It has an excellent effect of preventing.

Further, even if an outward force is applied to the strut, the elasticity of the ring seal pushes it back toward the center, thereby preventing the strut from detaching.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional ceramic gas turbine flow path, Fig. 2 is a sectional view similar to Fig. 1 showing an embodiment of this invention, and Fig. 3 is an exploded perspective view of the main part thereof. , FIGS. 4a and 4b are perspective views showing other examples of different shapes of struts, and FIG.
FIG. 7 is a sectional view of a main part of another embodiment using the strut shown in FIG. b; 1... Compressor turbine, 2... Power turbine, 3, 13... Gas flow path, 4, 14... Inner case, 5, 15... Outer case, 17,
37...Ring seal, 6, 16, 26, 36...
...Struts.

Claims (1)

[Scope of utility model registration request] A gas flow path that communicates between the compressor turbine and the power turbine of a two-shaft ceramic gas turbine is divided into an inner case and an outer case that are separate parts, and a strut that connects the inner case and the outer case to each other. 1. A gas flow path for a ceramic gas turbine, characterized in that each strut is pressed toward the center of an inner case by a ring seal from the outside of the outer case and assembled elastically.