JPS59180006A - Gas turbine stator blade segment - Google Patents

Abstract

PURPOSE:To lower thermal stress that may be induced in each of segments, by making the part between a blade and a side wall of a gas turbine stator blade to have a loose fit structure, the gas turbine stator blade being an assembly of segments each comprising the blade and side walls. CONSTITUTION:In a stator blade segment provided with one or more blades 1 between outer and inner side walls, to assemble the blade 1, fixing jigs 13, 14 are used. In the assembling, the blade 1 provided with the fixing jigs 13, 14 at the opposite ends is inserted from above of the outer side wall 2 and the fixing jig 14 is fixed by the inner side wall 3 and a welded section 15. The fixing jig 13 has steps and includes a structure that can engage with the outer side wall 2, and the wall 2 and the jig 13 are not fixed. To prevent cooling air from leaking between the outer side wall 2 and the fixing jig 13, if required, a sealing plate 16 is attached over the boundary between them and is fixed by a welded section 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a gas turbine silent blade structure, and particularly to a stator blade segment structure for completely preventing generation of excessive thermal stress in the blade portion.

[Prior art]

An example of purchasing a cast turbine silence segment is shown in FIGS. 1 to 3.

FIG. 1 is a perspective view of a stator vane segment. A stationary blade segment is composed of a blade 1, an outer sidewall 2, and an inner sidewall 3.A single blade segment is composed of a single blade and both sidewalls. A wing in which the wing is integrated with both sidewalls is called a fully multiple wing segment. The stator vane of an actual aircraft is made up of these segments connected in a cylindrical shape. FIG. 2 shows the internal structure 1 of the wing. Gas burned in the combustor 1
1 flows from the leading edge 4 of the blade toward the trailing edge 5. When the outer wall of the blade comes into contact with combustion gas, it becomes very hot and its strength will decrease unless it is cooled. For this reason, generally, the entire interior of the blade is hollow, and the metal surface is cooled by blowing cooling air onto the inner wall of the cavity. Core plug 6 with countless cooling holes 7 inside the wing
Fully insert the blade, let the cooling air 9 flow from the outer circumferential direction of the blade, and open the cooling hole 7.
After cooling air is blown out of the core plug and blown onto the inner wall of the blade, it passes through cooling holes 8.9 provided in the blade body and is blown out to the outside.

FIG. 3 is a view of the stator vane segment viewed from the outer side mail side of FIG. 1. The core flag 6 is joined to the sidewall on the side 1 at a welded part]2.

In this way, since the blade is cooled from the inside and heated from the outside, a temperature distribution occurs in the thickness direction, and the heat transfer coefficient differs depending on the location from the AtT edge to the trailing edge -f. Depending on the presence or absence of cooling holes, a temperature distribution can be created in the blade span direction. Since the wing is fixed by both the outer and inner sidewalls, thermal stress occurs. On the other hand, since the temperature of the sidewall is relatively low and the temperature of the wing is high, thermal stress is also generated due to the temperature difference between the two. In the case of a single segment, the sidewall deforms along with the deformation of the blade7, and there is room for thermal stress to be alleviated, but in the case of a multiple blade segment, the deformation of the sidewall is caused by the deformation of the adjacent blade. Due to the restraint, excessive stress is generated at the joint between the sidewall and the blade7, and thermal stress is repeated as the plant starts and stops, resulting in fatigue cracks.
Causes heavy damage to the plant.

In the figure, 5 is the trailing edge of the blade, 10 is the cooling air, 11 is the combustion gas, and 18 is the boundary between the upper fixing jig and the sidewall.

[Purpose of the invention]

An object of the present invention is to provide a highly reliable stator blade segment by reducing thermal stress generated in the stator blade segment and completely preventing fatigue and cracking.

[Summary of the invention]

Is the main point of this invention between the wing and the Zyde wall? The structural separation reduces the overall deformation constraints between the wing and sidewall.

[Embodiment of the invention I Embodiment 1 of the present invention is shown in FIGS. 4 to 6.

Fig. 4 is a plan view seen from the direction of the outer sidewall, Fig. 5 is a cross section between the dorsal side and the ventral side (IV-V), and Fig. 6 is a cross section between the leading edge and the rear edge (CM-Vl). FIG.

In the non-embodiment, the assembly structure is such that the outer and inner sidewalls 2 and 3 and the fixing jigs 13 and 14 are all provided at both ends of the wing 1. That is, the blade 1 with fixing jigs 13 and 14 is fully inserted from above the outer sidewall 2 and fixed to the inner sidewall 3 by the welded portion 15. Fixing jig 13
As shown in Fig. 5 and Fig. 6, the structure is such that the entire stage is gripped and hooked onto the outer side wall. It is assumed that the outer sidewall and the fixing jig 13 are not fixed. If there is no curvature in the root portion 20 of the blade 1, the flow of combustion gas will be poor and efficiency will be reduced. Due to the full curvature at the base, fixing jig 1
The boundaries between 3 and 14 and both side walls are provided at locations where the curvature disappears and the boundaries become flat.

With this structure, even when the plant is in operation and high-temperature combustion gas flows in, causing the blades to reach high temperatures and expand, the generation of thermal stress due to the full restraint of the sidewalls of adjacent blades is avoided. By straddling the L, the occurrence of cracks seen in conventional structures can be prevented, improving the reliability of the plant.

On the other hand, the blades are subjected to the pressure of combustion gas (more bending load), but this can be done by setting the clearance at the boundary 18 between the outer sidewall and the upper fixing jig to less than the allowable deformation of the entire blade. The wing 2 can be supported by utilizing the shape of the wing.

It is conceivable that cooling air leaks from the boundary between the outer sidewall and the upper fixture to the combustion gas passage side, reducing the efficiency of the plant. In this case, as shown in Figure 7,
Boundary between outer sidewall and fixing jig 1! - Lay it on the seal plate 16 so as to straddle it and fix it with the welded part 17. This completely prevents cooling air from leaking.

However, this seal plate is as thin as possible and does not completely restrict the deformation of the upper fixing jig 13 and the side wall 2.

In addition, as shown in Fig. 8, cooling slits are provided at the boundary between the upper fixing jig 13 and the outer sidewall 2, and these are fully utilized to blow cooling air directly onto the blades to cool the blades. It is also possible to implement

Furthermore, in this embodiment, the structure for adding stationary vanes to the casing can be similar to the conventional structure in which the stator vanes are suspended from the entire outer sidewall casing, and can be applied to gas turbines currently in operation. .

〔Effect of the invention〕

According to the present invention, it is possible to reduce thermal response chips occurring in the stator vane segments, and as a result, the reliability of the plant can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a stator blade segment, FIG. 2 is a perspective view of the blade structure, FIG. 3 is a plan view of the stator blade segment, FIG. 4 is a plan view of the stator blade segment of the present invention, and FIG. 5 is a perspective view of the stator blade segment. FIG. 6 is a cross-sectional view between the dorsal side and the ventral side of the stator vane segment of the present invention, FIG. 6 is a cross-sectional view between the leading edge and the trailing edge of the stator vane segment of the present invention, and FIG. FIG. 8 is a cross-sectional view of a stationary vane segment according to another embodiment of the present invention. ■... Wing, 2... Outer side wall, 3... Inner side wall, 7... Core plug cooling hole, 8...
... Wing abdomen cooling hole, 9... Wing trailing edge cooling hole, 10...
・Cooling air, (7) Chi 3 Figure JP 59-180006 (4) 4-2 Brown 5 Figure 15 Not (l = Kasumi JP + 1ff 59-18000 (5) 5 Figure 2 2-layered hatch/

Claims (1)

[Claims] 1. In a gas turbine stationary blade in which a blade and a sidewall form a sedamane lf and these segments are assembled, a Y loose fitting structure is provided between the sidewall and the blade part. One feature of the gas turbine stationary blade segment. 24% Permissible scope The gas turbine stationary blade according to claim 1, further comprising means 1 for forming a cooling pipe on the surface of the blade by utilizing a gap provided in the loose fitting structure. segment.