Sealing structure for turbines, and turbine and gas turbine having the same

Disclosed herein may be a sealing structure for turbines, and a turbine and a gas turbine having the sealing structure. The sealing structure is mounted on a sealing housing of a vane sealing assembly of the turbine to prevent combustion gas passing through a blade of the turbine from being drawn into an internal space between a disk of the turbine and the sealing housing. The sealing structure may include a mounting plate mounted to the sealing housing, and baffles which are provided on the mounting plate at positions spaced apart from each other and protrude toward the disk. Therefore, thanks to the sealing structure, turbulent currents are generated in the flow of combustion gas that passes through the turbine blade. The generated turbulent currents block space between the sealing structure and the turbine disk, thus preventing the combustion gas from flowing into the internal space.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No. 10-2017-0104111, filed on Aug. 17, 2017, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

Exemplary embodiments of the present disclosure relate to a sealing structure for turbines, and a turbine and a gas turbine having the sealing structure. More particularly, the exemplary embodiments relate to a sealing structure for turbines capable of preventing combustion gas passing through a blade of a turbine from being drawn into space between a disk and a vane sealing assembly, and a turbine and a gas turbine having the sealing structure.

Description of the Related Art

A turbine is a machine which generates a rotating force from an impulsive force or reaction force using a flow of compressive fluid such as steam or gas. The turbine is classified into a steam turbine using steam, a gas turbine using high-temperature combustion gas, and so forth. The gas turbine chiefly includes a compressor, a combustor, and a turbine. The compressor includes an air inlet into which air is introduced and a plurality of compressor vanes and compressor blades which are alternately provided in a compressor casing.

The combustor is configured to supply fuel to air compressed by the compressor and ignite the fuel mixture using a burner, thus generating high-temperature and high-pressure combustion gas.

The turbine includes a plurality of turbine vanes and a plurality of turbine blades which are alternately arranged in a turbine casing. Furthermore, a rotor is disposed through central portions of the compressor, the combustor, the turbine, and an exhaust chamber.

Opposite ends of the rotor are rotatably supported by bearings. A plurality of disks are fixed to the rotor, and the blades are coupled to the corresponding disks, respectively. A driving shaft of a generator or the like is coupled to an end of the rotor that is adjacent to the exhaust chamber.

The gas turbine does not have a reciprocating component, such as a piston of a four-stroke engine. Therefore, mutual friction parts, such as a piston-and-cylinder, are not present so that there is little consumption of lubricant, the amplitude of vibration is markedly reduced unlike a reciprocating machine having high-amplitude characteristics, and high-speed driving is possible.

A brief description of the operation of the gas turbine is as follows. Air compressed by the compressor is mixed with fuel, the fuel mixture is combusted to generate high-temperature combustion gas, and the generated combustion gas is discharged to the turbine. The discharged combustion gas passes through the turbine vanes and the turbine blades and generates a rotating force, by which the rotor is rotated.

SUMMARY OF THE DISCLOSURE

In the conventional gas turbine, a sealing housing is provided to seal space between disks of the turbine. However, the conventional gas turbine is problematic in that combustion gas that is supplied from the combustor and passes through the turbine blades is drawn into space between the disks and the sealing housing.

Various embodiments of the present disclosure are directed to a sealing structure for turbines capable of generating turbulent currents in the flow of combustion gas that passes through a turbine blade and is to be drawn into internal space between a turbine disk and a sealing housing, thus preventing the combustion gas from flowing into the internal space, and a turbine and a gas turbine having the sealing structure.

In accordance with one aspect of the present disclosure, a sealing structure for a turbine, the sealing structure being mounted on one surface of a sealing housing of a vane sealing assembly of the turbine so as to prevent combustion gas passing through a blade of the turbine from being drawn into an internal space between a disk of the turbine and the sealing housing, wherein the sealing structure may include: a mounting plate mounted to the sealing housing; and a plurality of baffles provided on the mounting plate at positions spaced apart from each other with respect to a direction from an upper end of the mounting plate to a lower end thereof, the plurality of baffles protruding toward the disk.

In an embodiment, the plurality of baffles provided on the mounting plate may have lengths different from each other. The length of the baffle that is provided on the upper end of the mounting plate may be shortest. The lengths of the baffles may be gradually increased from the upper end of the mounting plate to the lower end thereof.

In an embodiment, the plurality of baffles may be integrally formed with the mounting plate.

In an embodiment, an inducing depression for inducing a flow of combustion gas which is drawn into the internal space may be formed in each of the plurality of baffles. The inducing depression may be formed in a rounded shape in an end of the baffle.

In an embodiment, a plurality of inducing holes for inducing a flow of combustion gas which is drawn into the internal space may be respectively formed in the plurality of baffles. Each of the inducing holes may be formed in the corresponding baffle in an inclined direction.

In an embodiment, the plurality of baffles may protrude from one surface of the mounting plate in an upwardly inclined direction.

In an embodiment, the plurality of baffles may be formed on one surface of the mounting plate in an upwardly rounded shape.

In accordance with another aspect of the present disclosure, a turbine configured to allow combustion gas supplied from a combustor to pass through an interior of the turbine to generate driving force for generating electric power, the turbine including: a rotor comprising a plurality of disks, and a plurality of blades respectively coupled to outer surfaces of the plurality of disks; a stator comprising a casing for housing the rotor therein, a plurality of vanes installed on an inner circumferential surface of the casing and disposed between the plurality of blades, and a vane sealing assembly installed on an end of each of the vanes; and a sealing structure mounted to the vane sealing assembly and configured to prevent combustion gas passing through the blades from being drawn into an internal space between the corresponding disk and the vane sealing assembly.

In an embodiment, the vane sealing assembly may include: a shroud coupled to an end of the turbine vane; and a sealing housing coupled to the shroud and configured to seal space between the corresponding disks, wherein the sealing structure may be mounted to the sealing housing.

In an embodiment, the sealing structure may include: a mounting plate mounted to the sealing housing; and a plurality of baffles provided on the mounting plate at positions spaced apart from each other with respect to a direction from an upper end of the mounting plate to a lower end thereof, the plurality of baffles protruding toward the disk. The plurality of baffles provided on the mounting plate may have lengths different from each other. The length of the baffle that is provided on the upper end of the mounting plate may be shortest. The lengths of the baffles may be gradually increased from the upper end of the mounting plate to the lower end thereof.

In an embodiment, an inducing depression for inducing a flow of combustion gas which is drawn into the internal space may be formed in each of the plurality of baffles. The inducing depression may be formed in a rounded shape in an end of the baffle.

In an embodiment, a plurality of inducing holes for inducing a flow of combustion gas which is drawn into the internal space may be respectively formed in the plurality of baffles. Each of the inducing holes may be formed in the corresponding baffle in an inclined direction.

In an embodiment, the plurality of baffles may protrude from one surface of the mounting plate in an upwardly inclined direction.

In an embodiment, the plurality of baffles may be formed on one surface of the mounting plate in an upwardly rounded shape.

In accordance with yet another aspect of the present disclosure, a gas turbine including: a compressor configured to draw air thereinto and compress the air; a combustor configured to combust fuel using compressed air supplied from the compressor and generate combustion gas; and a turbine. The turbine may include: a rotor configured to be rotated by the combustion gas supplied from the combustor, and comprising a plurality of disks, and a plurality of blades respectively coupled to outer surfaces of the plurality of disks; a stator comprising a casing for housing the rotor therein, a plurality of vanes installed on an inner circumferential surface of the casing and disposed between the plurality of blades, and a vane sealing assembly installed on an end of each of the vanes; and a sealing structure mounted to the vane sealing assembly and configured to prevent combustion gas passing through the blades from being drawn into an internal space between the corresponding disk and the vane sealing assembly.

In an embodiment, the vane sealing assembly may include: a shroud coupled to an end of the turbine vane; and a sealing housing coupled to the shroud and configured to seal space between the corresponding disks. The sealing structure may include: a mounting plate mounted to the sealing housing, and a plurality of baffles provided on the mounting plate at positions spaced apart from each other with respect to a direction from an upper end of the mounting plate to a lower end thereof, the plurality of baffles protruding toward the disk. The plurality of baffles provided on the mounting plate may have lengths different from each other. The length of the baffle that is provided on the upper end of the mounting plate may be shortest. The lengths of the baffles may be gradually increased from the upper end of the mounting plate to the lower end thereof.

In an embodiment, an inducing depression for inducing a flow of combustion gas which is drawn into the internal space may be formed in each of the plurality of baffles. The inducing depression may be formed in a rounded shape in an end of the baffle.

In an embodiment, a plurality of inducing holes for inducing a flow of combustion gas which is drawn into the internal space may be respectively formed in the plurality of baffles. Each of the inducing holes may be formed in the corresponding baffle in an inclined direction.

In an embodiment, the plurality of baffles may protrude from one surface of the mounting plate in an upwardly inclined direction.

In an embodiment, the plurality of baffles may be formed on one surface of the mounting plate in an upwardly rounded shape.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Hereinafter, a sealing structure for turbines, and a turbine and a gas turbine having the sealing structure in accordance with the present disclosure will be described with reference to the accompanying drawings.

Referring toFIG. 1, a gas turbine10in accordance with an embodiment of the present disclosure includes a tie rod11, a compressor12, a combustor13, and a turbine100. The tie rod11is a rod installed through a central portion of the gas turbine10. The tie rod11functions to couple the compressor12with the turbine100.

The compressor12functions to draw air thereinto and compress the air. Based on the direction of air flow, the compressor12is installed in an upstream portion of the gas turbine10. The combustor13functions to combust fuel supplied from an external fuel tank (not shown) using compressed air supplied from the compressor12, and supply combustion gas generated by combustion of the fuel to the turbine100.

The turbine100allows the combustion gas supplied from the combustor13to pass through an interior of the turbine to generate a driving force for generating electric power. The turbine100includes a rotor110, a stator120, and a sealing structure130(SeeFIG. 2).

The rotor110is rotated by combustion gas supplied from the combustor13. The rotor110includes a plurality of disks112, and a plurality of blades114. The plurality of disks112are installed on an outer circumferential surface of the tie rod11. The plurality of blades114are respectively coupled to radial outer surfaces of the plurality of disks112. Combustion gas drawn into the turbine100pushes the blades114while passing through the blades114, whereby the blades114and the disks112rotate with the tie rod11functioning as a center axis.

The stator120functions to provide a path enabling combustion gas that has passed through each pre-stage blade114to be supplied to a corresponding rear-stage blade114. The stator120includes a casing121, a plurality of vanes122, and a vane sealing assembly123(SeeFIG. 2).

The casing121houses the rotor110therein. The plurality of vanes122are installed on an inner circumferential surface of the casing121toward the tie rod11. Preferably, the plurality of vanes122may be disposed between the plurality of blades114.

Referring toFIG. 2, the vane sealing assembly123is installed on an end of each of the plurality of vanes122. The vane sealing assembly123includes a shroud124and a sealing housing125. The shroud124is coupled to the end of the vane122. The sealing housing125is coupled to the shroud124and disposed in space defined between the adjacent pre-stage disk112and the adjacent rear-stage disk112so as to seal the space.

The sealing structure130is mounted on one surface of the sealing housing125. The sealing structure130functions to prevent combustion gas that has passed through the blades114from being drawn into internal space between the corresponding disk112and the sealing housing125of the vane sealing assembly123.

The sealing structure130includes a mounting plate132and a plurality of baffles134(SeeFIG. 3). The mounting plate132has a planar shape and is mounted on the one surface of the sealing housing125. It is preferable that the mounting plate132be mounted on one surface of the sealing housing125by a coupling unit (not shown) or welding.

Preferably, in the case where the mounting plate132is mounted to the sealing housing125using the coupling unit (not show), a through hole132athrough which the coupling unit (not shown) passes may be formed in the mounting plate132. It is preferable that a plurality of through holes132abe formed in the mounting plate132so that the mounting plate132can be reliably mounted to the sealing housing125.

A plurality of baffles134protruding toward the disk112are provided on one surface of the mounting plate132. It is preferable that the plurality of baffles134be arranged on one surface of the mounting plate132at positions spaced apart from each other from an upper end of the one surface of the mounting plate132to a lower end thereof. The plurality of baffles134have lengths different from each other. Preferably, the baffle134that is provided on the upper end of the mounting plate132may be the shortest, and the lengths of the baffles134may be gradually increased from the upper end of the mounting plate132to the lower end thereof. Preferably, the length of the baffle134provided on the lower end of the mounting plate132may be the longest.

Referring toFIGS. 3 to 6, preferably, the mounting plate132and the plurality of baffles134are integrally formed. It is preferable that inducing depressions134aor inducing holes134bbe respectively formed in the plurality of baffles134so that turbulent currents can be generated in the flow of combustion gas that has passed through the blades114and is to be drawn into the internal space between the corresponding disk112and the sealing housing125.

Referring toFIGS. 3 and 4, the inducing depressions134afor generating the turbulent currents in the flow of combustion gas drawn into the internal space are respectively formed at the ends of the respective baffles134. The inducing depressions134aformed at the end of each baffle134have a rounded shape. Due to the rounded inducing depression134a, the flow of combustion gas drawn onto an upper portion of the baffle134is induced to a side surface of the baffle134and then collides with one surface of the disk112, thus generating the turbulent currents.

Referring toFIGS. 5 and 6, the inducing holes134bfor generating the turbulent currents in the flow of combustion gas drawn into the internal space are formed in the respective baffles134. Preferably, the inducing hole134bformed in each baffle134may have an inclined shape. Due to the inducing holes134b, the flow of combustion gas drawn onto the upper portion of the baffle134is induced to the side surface of the baffle134and then collides with one surface of the disk112, thus generating the turbulent currents.

The present disclosure is not limited to the structure in which only either the inducing depression134aor the inducing hole134bis formed in each baffle134. In order to increase the effect of generating turbulent currents in the flow of combustion gas to be drawn into the internal space, both the inducing depression134aand the inducing hole134bmay be formed in each baffle134.

Referring toFIGS. 7 and 8, a plurality of baffles134′ may be formed to protrude from one surface of the mounting plate132in an upwardly inclined direction. Due to the plurality of baffles134′ protruding in the upwardly inclined direction, the flow of combustion gas drawn onto an upper portion of each baffle134′ is induced to a side surface of the baffle134′ and then collides with one surface of the corresponding disk112, thus generating turbulent currents. The generated turbulent currents block space between the sealing structure130and the corresponding turbine disk112, thereby preventing combustion gas from flowing into the internal space between the turbine disk112and the sealing housing125.

Referring toFIGS. 9 and 10, the plurality of baffles134″ may be formed on one surface of the mounting plate132in an upwardly rounded shape. Due to the plurality of baffles134″ formed to protrude in the upwardly rounded shape, the flow of combustion gas drawn onto an upper portion of each baffle134″ is induced to a side surface of the baffle134″ and then collides with one surface of the corresponding disk112, thus generating turbulent currents.

The present disclosure is not limited to the structure in which the baffles134′ or134″ protrude from the one surface of the mounting plate132in an inclined or rounded shape. For example, either or both the inducing depression134aand the inducing hole134bmay be formed in each baffle134′ or134″ so that the flow of combustion gas drawn onto the upper portion of the baffle134′ or134″ can be more effectively induced to the side surface of the baffle134′ or134″ and then collide with the one surface of the corresponding disk112to generate the turbulent currents.

The disks112are rotational bodies which rotate along with the blades114when the blades114rotate. The vane122, the shroud124, and the sealing housing125are fixed on the casing121, i.e., which is a stationary body against the rotation of the blades114.

When the disks112rotate at high speeds, some combustion gas may be drawn into space between the disks112and the sealing housing125and flow into the internal space. Here, the sealing structure130mounted on one surface of the sealing housing125generates turbulent currents in the flow of combustion gas that is drawn into space between the corresponding disk112and the sealing housing125and flows into the internal space. The generated turbulent currents block the space between the sealing structure130and the turbine disk112, thus preventing the combustion gas from flowing into the internal space between the turbine disk112and the sealing housing125.

Various embodiments of the present disclosure may provide a sealing structure for turbines, and a turbine and a gas turbine having the sealing structure. In the embodiments of the present disclosure, thanks to the sealing structure mounted to the sealing housing, turbulent currents are generated in the flow of combustion gas that passes through the turbine blade and is to be drawn into the internal space between the turbine disk and the sealing housing. The generated turbulent currents block space between the sealing structure and the turbine disk, thus preventing the combustion gas from flowing into the internal space between the turbine disk and the sealing housing.