Steam turbine stationary blade and steam turbine

Patent metadata

Field	Value
Publication number	US-9598964-B2
Application number	US-201314019755-A
Country	US
Kind code	B2
Filing date	Sep 6, 2013
Priority date	Sep 14, 2012
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A plurality of slots with different widths are provided in a plurality of line on a stationary blade surface. More specifically, the steam turbine stationary blade has a hollow nozzle with a penetrating space, which is connected with a diaphragm outer ring or inner ring, and a plurality of suction slots extending radially which are arranged on the blade surface. At a position where a water film deposited to the blade surface is thick, the width of a slot is smaller and at a position where the water film is thin, the width of a slot is larger.

First claim

The invention claimed is:

1. A steam turbine stationary blade with a hollow inner portion, including:
a plurality of slots formed on a blade surface of the steam turbine stationary blade, extending in a blade height direction and provided in a plurality of lines,
wherein the slots are located on a pressure side of the stationary blade,
wherein the slots include a first slot located upstream in the turbine axial direction and a second slot located downstream of the first slot and having a slot width larger than the slot width of the first slot,
wherein the first slot is located at a position within a range of l/L ratio from 0.6 to 0.8 where l represents a distance along the blade surface from a leading edge of the stationary blade to a given position on the blade surface and L represents a distance along the blade surface from the leading edge of the stationary blade to a trailing edge of the stationary blade,
wherein the second slot is located at a position where the l/L ratio is larger than at the position of the first slot, and
wherein the steam turbine stationary blade with the hollow inner portion is made of a plastically deformed metal plate.

2. The steam turbine stationary blade according to claim 1 ,
wherein the first slot is 0.5 mm to 1.0 mm in width.

3. The steam turbine stationary blade according to claim 2 ,
wherein the first slot is about 0.5 mm in width and the second slot is about 1 mm in width.

4. A steam turbine having a turbine stage comprising a steam turbine stationary blade and a moving blade located downstream of the steam turbine stationary blade in a working fluid flow direction,
wherein the steam turbine stationary blade according to claim 3 is used as the steam turbine stationary blade.

5. A steam turbine having a turbine stage comprising a steam turbine stationary blade and a moving blade located downstream of the steam turbine stationary blade in a working fluid flow direction,
wherein the steam turbine stationary blade according to claim 2 is used as the steam turbine stationary blade.

6. The steam turbine stationary blade according to claim 1 ,
wherein the slots provided in the plurality of lines are arranged in a broken line pattern in the blade height direction respectively.

7. A steam turbine having a turbine stage comprising a steam turbine stationary blade and a moving blade located downstream of the steam turbine stationary blade in a working fluid flow direction,
wherein the steam turbine stationary blade according to claim 6 is used as the steam turbine stationary blade.

8. A steam turbine having a turbine stage comprising a steam turbine stationary blade and a moving blade located downstream of the steam turbine stationary blade in a working fluid flow direction,
wherein the steam turbine stationary blade according to claim 1 is used as the steam turbine stationary blade.

Assignees

• Mitsubishi Hitachi Power Sys

Inventors

• Ishibashi Koji
• Nakano Susumu
• Mizumi Shunsuke
• Kudo Takeshi

Classifications

• F01D5/145

  Means for influencing boundary layers or secondary circulations (for compressors F04D29/68) · CPC title

• F05D2240/124

  related to the suction side of a stator vane · CPC title

• F01D5/18 Primary

  Hollow blades, {i.e. blades with cooling or heating channels or cavities (structure of hollow blades in general F01D5/147)}; Heating, heat-insulating or cooling means on blades · CPC title

• F01D25/32

  Collecting of condensation water; Drainage {; Removing solid particles} · CPC title

• F05D2220/31

  in steam turbines · CPC title