JPH0861007A - Stator blade device for steam turbine - Google Patents

Abstract

PURPOSE: To provide a structure having neither a gap nor a half blade for causing steam leakage in the upper and lower divided parts of a stator blade wheel. CONSTITUTION: The divided surfaces of a stator blade wheel 1 constituting the stator blade device of a steam turbine are formed in a composite divided surface in which each inner diameter side part 2 is each slantly divided surface A passing through the blades and having a mutual gap and each outer diameter side part 3 is each horizontally divided surface B stuck to each other. Thus, generation of gaps or half blades causing steam leakage on the divided surface of the stator blade wheel is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam turbine stationary blade device, and more particularly to a divided structure of a stationary blade ring.

[0002]

2. Description of the Related Art A stationary vane ring in a stationary vane device of a steam turbine is divided into upper and lower parts, but the conventional vane ring has a structure shown in FIGS. There are roughly two types of conventional structures of the upper and lower divided portions of the stationary vane wheel.

That is, one is to divide the stator blade obliquely along the profile 11 of the vane as shown in FIGS. 3 and 4, and the other is to divide it as shown in FIGS. The vane ring 12 is divided horizontally, and the vane that hits the divided surface is the half-blade 1.
3, which is reinforced with pins 14 and the like.

[0004]

The structure of the conventional upper and lower split portions of the stationary vane ring is as described above. However, in the structures shown in FIG. 3 and FIG. For this reason, it is usually necessary to provide a gap of about 1.6 mm, and there is a drawback that steam leaks through this gap.

5 and 6, the upper and lower split parts can be aligned in the horizontal plane without any gap, but as shown in the figure, the stationary blades that hit the horizontal split surface are divided into half blades. Therefore, it is necessary to take measures such as reinforcing the divided stationary blades with pins, and due to these reinforcing structures, it is not possible to form a smooth flow path for steam, and there is the disadvantage that performance must be sacrificed. is there.

The present invention has been made in order to eliminate these drawbacks, and a static turbine of a steam turbine having a structure that does not generate a gap that causes steam leakage in the upper and lower split portions of the stationary vane ring and a half blade that requires reinforcement. An object is to provide a wing device.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems in a steam turbine stator vane device having vertically divided stator vanes, the present invention is designed so that the inner diameter side portion of the split surface of the stator vane is placed between the blades. A diagonal dividing surface that passes through and a composite dividing surface in which the outer diameter side portion is a horizontal dividing surface.

Further, the diagonal dividing surface has a gap between the facing diagonal dividing surface, and the horizontal dividing surface is in close contact with the facing horizontal dividing surface.

[0009]

In the stator vane device according to the present invention, since the upper and lower split faces of the stator vane ring are composed of the complex split faces in which the diagonal split faces on the inner diameter side and the horizontal split faces on the outer diameter side are combined, Leakage of steam passing through the gap between the dividing surfaces is blocked by the horizontal dividing surface on the outer diameter side.

Further, since the dividing surface on the inner diameter side is an oblique dividing surface that passes between the blades, it is possible to prevent the stationary blade from hitting the dividing surface and becoming a half blade. Therefore, it is not necessary to reinforce the vane with pins. Therefore, it is possible to eliminate the drawbacks that the conventional vane devices have.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on an embodiment shown in FIGS. FIG. 1 is a side view of the divided portion of the stationary vane ring on the inner diameter side. FIG. 2 is a perspective view of a lower side portion of the divided stationary vane ring. Inner diameter side part 2 of vane wheel 1
Divides the stator vanes 4 obliquely to form a dividing surface A. The outer diameter side portion 3 of the stationary vane wheel 1 is horizontally divided to form a dividing surface B.

As described above, the upper and lower divided portions of the stationary vane ring 1 are formed as the compound divided surfaces composed of the diagonal divided surface A and the horizontal divided surface B, so that the horizontal divided surface B is blocked by the steam leakage passing through the gap. And the stationary blade 4 can be prevented from becoming a half blade due to the slanted dividing surface A passing between the blades.
Therefore, it is not necessary to reinforce the stationary blade with the pin, which is seen in the conventional one.

[0013]

In the stator vane device of the present invention, the stator vane ring is divided by a compound dividing face composed of an oblique dividing face on the inner diameter side and a horizontal dividing face on the outer diameter side. The problems such as steam leakage from the gap, generation of half blades in horizontal division, and reinforcement thereof, which have occurred in conventional diagonal division, are eliminated.

Therefore, in the stationary blade device according to the present invention, not only the performance is improved but also the strength of the blade is secured, so that the effect of improving the quality of the steam turbine is extremely large.

[Brief description of drawings]

FIG. 1 is a side view of a composite divided surface portion of a stationary blade device according to an embodiment of the present invention as viewed from an inner diameter side.

FIG. 2 is a perspective view of a lower portion of a composite dividing surface in the stationary blade device shown in FIG.

FIG. 3 is a side view of an oblique dividing surface portion in a conventional vane device.

FIG. 4 is a side view of another oblique division surface portion in the conventional vane device.

FIG. 5 is a side view of a horizontal split surface portion of a conventional vane device.

FIG. 6 is a side view of another horizontal division surface portion in the conventional vane device.

[Explanation of symbols]

 1 stationary vane ring 2 inner diameter side part 3 outer diameter side part 4 stationary vane A diagonal dividing surface B horizontal dividing surface

Claims (1)

[Claims] 1. A steam turbine stationary vane device having vertically divided stationary vanes, wherein a dividing surface of the stationary vane is an oblique dividing surface having an inner diameter side portion between the blades and a gap therebetween, and an outer portion. A stationary vane device for a steam turbine, characterized in that the radial side portion is composed of a composite dividing surface which is a horizontal dividing surface in close contact with each other.