GAS TURBINE

• US 20190331026A1
• Filed: 04/15/2019
• Published: 10/31/2019
• Est. Priority Date: 04/27/2018
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: IIDA, Koichiro, OKABE, Yoshiyuki, OYA, Yoshiko
• Granted Patent: US 11,131,246 B2
• Time in Patent Office: Days
• CPC Class Codes: F01D 11/001 for sealing space between stator blade and rotor
• CPC Class Codes: F01D 11/04 using sealing fluid, e.g. steam
• CPC Class Codes: F01D 9/065 Fluid supply or removal conduits traversing the working fluid flow, e.g. for lubrication-, cooling-, or sealing fluids see also F01D25/16, F01D25/24 and F01D25/26
• CPC Class Codes: F02C 7/28 Arrangement of seals
• CPC Class Codes: F05D 2220/32 in gas turbines
• CPC Class Codes: F05D 2240/24 for turbines
• CPC Class Codes: F05D 2240/55 Seals
• CPC Class Codes: F05D 2250/314 the axes being inclined in relation to each other

Abstract

A gas turbine includes the rotor that has a rotor disk at each of a plurality of stages and a plurality of blades fixed to the respective stages, a casing, the plurality of vanes fixed to the casing, and an annular member fixed to a radially inner side of each of the vanes. The rotor disk has a seal arm. The annular member has an outer opposing portion that radially opposed to a seal arm. The gas turbine further includes a seal fin that protrudes from the outer opposing portion toward the seal arm, a first cavity that is formed in the annular member and extends in a circumferential direction to straddle at least two vanes, a second cavity that is provided on the radially inner side of the first cavity, and a plurality of compressed air discharge paths that connect the first cavity to the second cavity.

Claims

1. A gas turbine comprising:

a rotor that rotates around an axis, the rotor having a rotor disk stacked at each of a plurality of stages in an axial direction and a plurality of blades fixed to the respective stages of the rotor disks;

a casing that covers the rotor rotatable;

a plurality of vanes fixed to the casing to correspond to the plurality of blades at the respective stages;

an inner shroud provided on a radially inner side of each of the vanes; and

an annular member fixed to the radially inner side of each of the inner shrouds,

wherein the rotor disk has a seal arm that protrudes to a downstream side of the axial direction of the rotor disk,

the annular member has an outer opposing portion that is disposed radially outward of the seal arm and radially opposed to the seal arm, and

the gas turbine further comprises

a seal fin that protrudes from an inner circumferential surface of the outer opposing portion of the annular member toward an outer circumferential surface of the seal arm, extends in a circumferential direction, and forms a tapered shape of which a diameter decreases as going toward an upstream side of the axial direction;

a first cavity that is formed by being surrounded by the annular member and the inner shroud and extends in the circumferential direction to straddle at least two vanes out of the plurality of vanes;

a second cavity that is provided on a radially outer side of the seal fin and on the radially inner side of the first cavity, communicates and extends in the circumferential direction, and is open to the radially inner side;

a compressed air supply path through which compressed air is introduced into the first cavity; and

a plurality of compressed air discharge paths that are provided at an interval in the circumferential direction and connect the first cavity to the second cavity.

2. The gas turbine according to claim 1,

wherein an angle formed between the seal fin and the axis is 50°

or less.

3. The gas turbine according to claim 1, further comprising:

a concave portion formed on the radially inner side of the annular member; and

a guide plate that is connected to the downstream side of the axial direction of the seal fin, extends in the circumferential direction, wherein the second cavity is formed between the concave portion and the guide plate.

4. The gas turbine according to claim 1,

wherein a surface of the second cavity, which opposes the seal fin, is parallel to the seal fin.

5. The gas turbine according to claim 1, further comprising:

an upstream seal fin that protrudes from the inner circumferential surface of the outer opposing portion of the annular member toward the outer circumferential surface of the seal arm, extends in the circumferential direction, and opposes the seal fin via the second cavity.