JPH09242505A - Turbine structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance sealing characteristics and improve efficiency and reliability by overlapping the tip ends of diaphragms adjacent to each other in an axial direction in a gas turbine rotor. SOLUTION: A plurality of turbine moving blades 1 are fitted around the outer periphery. The tip ends of diaphragms 6 adjacent to each other are tapered, and are assembled in a manner overlapped with each other in an axial direction. Even if the diaphragms 6 are deformed by centrifugal force during operation of a gas turbine, no gap is produced in the axial direction. The diaphragm 6 positioned on the inner circumferential side is set smaller in bending rigidity than the other positioned on the outer peripheral side, so that sealing can be carried out by contact at the time of deformation by the centrifugal force. Consequently, it is possible to improve a sealing function so as to enhance efficiency, and to prevent combustion gas from flowing into the inner circumferential side of a disk so as to enhance reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine rotor structure for a gas turbine, and more particularly to a seal structure for improving efficiency and reliability.

[0002]

2. Description of the Related Art In recent years, gas turbines have been used for electric power, due to the development of a combined power generation system in combination with a steam turbine that uses exhaust gas, while increasing the temperature and efficiency of the gas turbine itself.
It is rapidly becoming popular for business use. In order to improve the efficiency of the gas turbine, it is important to reduce the loss due to leakage of combustion gas and cooling air as well as the combustion temperature. Further, the prevention of leakage of combustion gas, cooling air, etc. is important from the viewpoint of reliability because it can prevent unexpected high temperature of the rotor disk and the like.

Such a leakage prevention mechanism is necessary for each part of the gas turbine, but there is a general example of utilizing a diaphragm in the prior art relating to the turbine rotor.
Japanese Patent Laid-Open No. 61-226502 discloses a specific example as a drawing as a part of the description. In the present embodiment, a diaphragm is provided on the side surface of the turbine rotor, and a labyrinth seal or the like is used to seal between the outer peripheral surface of the diaphragm and the shroud arranged at the tips of the plurality of vanes fitted to the casing. It is effective in preventing leakage of gas or cooling air.

[0004]

Although the prior art is effective as a seal structure, there are the following problems in order to further improve the efficiency. That is, since the diaphragm is provided as a protruding ring on the side surface of the rotor disk, it is deformed to the outer peripheral side by centrifugal force during operation of the gas turbine, and the gap between the adjacent diaphragm tips becomes larger than the initial set value. Also, due to this deformation, the gap between the outer peripheral surface of the diaphragm and the shroud cannot maintain a constant dimension,
A labyrinth seal alone may be difficult to achieve a sufficient seal.

[0005]

In order to solve the above problems, the problems are solved by overlapping the tips of adjacent diaphragms. Alternatively, the problem can be solved by adding another component such as a seal ring.

According to the present invention, since the tips of the adjacent diaphragms are axially overlapped with each other at the time of assembly, even if they are deformed by a centrifugal force, they contact each other or keep a minute gap to secure a sealing function. it can. Even when the seal ring is provided, the deformation of the seal ring follows or restrains the deformation of the diaphragm, so that the sealing function can be ensured.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a gas turbine rotor structure of the present invention will be described below with reference to the drawings.

FIG. 13 shows a turbine rotor structure of a gas turbine using a conventional technique. A turbine disk 2 having a plurality of turbine rotor blades 1 fitted therein has three stages in this conventional example.
Along with the upstream distant piece 3 and the downstream stub shaft 4, a plurality of stacking bolts 5 are fastened at a position of equal radius from the central axis. Each disk of the turbine has a diaphragm 6 on both sides or one side.
Is provided. The casing 7 has a turbine rotor blade 1
Turbine vanes 8 are fitted in an arrangement alternating with.
A shroud 9 is fitted to the tip of the turbine vane 8 on the inner peripheral side, and a labyrinth seal 10 is arranged at the tip of the shroud. In this conventional example, the sealing mechanism for preventing leakage between the gas path portion 11 and the turbine disk 2 functions by the labyrinth seal 10 between the outer peripheral surface of the diaphragm 6 and the inner peripheral surface of the shroud 9 provided on the turbine disk 2. ing.

In this conventional embodiment, a centrifugal force acts upon the start of the gas turbine, and during the rated operation, the projecting diaphragm 6 is deformed so that its tip warps toward the outer peripheral side. Therefore, there is a problem that a gap is generated between the diaphragms 6 in the axial direction. Further, since the distance between the outer peripheral surface of the diaphragm and the inner peripheral surface of the shroud is not constant due to the deformation of the diaphragm 6, there is a possibility that the sealing function may be impaired by combining them.

FIG. 1 shows an embodiment of the present invention for solving this problem. In this embodiment, the tips of the diaphragms 6 adjacent to each other have a tapered shape and are assembled by overlapping in the axial direction. Therefore, even if the diaphragm 6 is deformed by centrifugal force during operation of the gas turbine, no gap is generated in the axial direction, and the bending rigidity of the diaphragm located on the inner peripheral side is greater than the bending rigidity of the diaphragm located on the outer peripheral side. By making it small, it is possible to seal by contact when deformed by centrifugal force.

Although another embodiment is shown in FIG. 2, in this embodiment, the same effect can be obtained by forming the tip of the diaphragm 6 in a stepped shape.

In the embodiment of FIG. 3, a groove 12 is provided in one of the tips of the adjacent diaphragms 6, and a protrusion 13 is provided in the other end.
By providing both with each other, it is possible to seal by contact when deformed by centrifugal force. In addition, the structure of the present invention prevents deformation due to centrifugal force from occurring in the groove 1.
It can be suppressed by restraining 2 and the protrusion 13.

FIG. 4 shows an embodiment based on a different idea. In the present embodiment, a seal ring 14 which is a separate component is arranged on the outer peripheral side of the adjacent diaphragms 6, and the seal functions between the seal ring and the inner peripheral surface of the shroud. Therefore, even if the diaphragm 6 is deformed by centrifugal force, the sealing function does not change, and the deformation of the diaphragm 6 can be suppressed by the seal ring 14.

FIG. 5 shows an embodiment in which a step is provided on the outer peripheral surface of the diaphragm 6 and a seal ring 14 is provided.

FIG. 6 shows an embodiment in which the seal ring 14 is arranged on the inner peripheral side of the adjacent diaphragms 6, and the sealing function is not impaired even if an axial gap is created at the tip of the diaphragm 6 by centrifugal force. Few.

7 and 8 show an embodiment in which the tips of the diaphragm 6 and the seal ring 14 are tapered.

FIG. 9 and FIG. 10 show an embodiment in which the diaphragm 6 and the seal ring 14 have a curved end.

FIG. 11 shows an embodiment in which a groove 12 is provided at the tip of the adjacent diaphragm 6 and a seal ring 14 is inserted into the groove 12. In this embodiment, the seal ring 14 can improve the sealing function and suppress the deformation of the diaphragm 6.

FIG. 12 shows an embodiment of the present invention in which an O-ring 15 seals between adjacent diaphragms 6.

[0020]

EFFECTS OF THE INVENTION By making the tips of adjacent diaphragms overlap each other, or by disposing a seal ring, the sealing function is improved and the efficiency is improved, and the inflow of combustion gas to the inner peripheral side of the disk is prevented. Thus, it is possible to improve reliability.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention in which a diaphragm tip has a tapered shape and is axially overlapped.

FIG. 2 is an explanatory view of an embodiment of the present invention in which the tip of the diaphragm is stepped.

FIG. 3 is an explanatory diagram of an embodiment of the present invention in which a groove and a protrusion are provided at the tip of an adjacent diaphragm.

FIG. 4 is an explanatory view of an embodiment of the present invention in which a seal ring is arranged.

FIG. 5 is an explanatory view of an embodiment of the present invention in which a seal ring is arranged on a diaphragm step.

FIG. 6 is an explanatory diagram of an embodiment in which a seal ring is arranged on the inner peripheral side of a diaphragm.

FIG. 7 is an explanatory diagram of an embodiment in which the tips of the diaphragm and the seal ring are tapered.

FIG. 8 is an explanatory diagram of an embodiment in which the tips of the diaphragm and the seal ring are tapered.

FIG. 9 is an explanatory view of an embodiment in which the diaphragm and the seal ring have curved ends.

FIG. 10 is an explanatory diagram of an embodiment in which curved surfaces are provided at the tips of the diaphragm and the seal ring.

FIG. 11 is an explanatory view of an embodiment of the present invention in which a seal ring is inserted in a groove.

FIG. 12 is an explanatory view of an embodiment of the present invention sealed with an O-ring.

FIG. 13 is an explanatory diagram of a turbine rotor using a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Turbine blade, 2 ... Turbine disk, 3 ... Distant piece, 4 ... Stub shaft, 5 ... Stacking bolt, 6 ... Diaphragm, 7 ... Casing, 8 ... Turbine vane, 9 ... Shroud, 10 ... Labyrinth seal,
12 ... Groove, 13 ... Projection, 14 ... Seal ring, 15 ... O
-Ring.

Claims (9)

[Claims] 1. In a gas turbine rotor having a plurality of turbine rotor blades fitted to the outer periphery, wherein adjacent gas turbine rotor disks are mutually sealed by a diaphragm provided on a side surface, the tips of the adjacent diaphragms are shafted. A gas turbine rotor characterized by overlapping in the direction. 2. The gas turbine rotor according to claim 1, wherein the tip of the diaphragm is tapered. 3. The gas turbine rotor according to claim 1, wherein the tip of the diaphragm is stepwise. 4. The gas turbine rotor according to claim 1, wherein a groove or a projection is provided at the tip of the diaphragm. 5. A gas turbine rotor having a plurality of turbine rotor blades fitted to the outer periphery thereof, wherein a diaphragm provided on a side surface seals adjacent gas turbine rotor disks from each other. A gas turbine rotor characterized by being sealed with a seal ring. 6. The gas turbine rotor according to claim 5, wherein the seal ring is arranged on an inner peripheral side or an outer peripheral side of the diaphragm. 7. The gas turbine rotor according to claim 5, wherein the seal ring is fitted with a diaphragm. 8. The gas turbine rotor according to claim 5, wherein a diaphragm contact portion of the seal ring has a taper. 9. The seal ring according to claim 5, wherein the seal ring is O.
A gas turbine rotor that is a ring.