WO2015108354A1

WO2015108354A1 - Blade tip sealing apparatus for gas turbine

Info

Publication number: WO2015108354A1
Application number: PCT/KR2015/000443
Authority: WO
Inventors: 김경국; 정성철
Original assignee: 두산중공업 주식회사
Priority date: 2014-01-16
Filing date: 2015-01-15
Publication date: 2015-07-23
Also published as: KR101509384B1

Abstract

Disclosed is a blade tip sealing apparatus for a gas turbine, the blade tip sealing apparatus which can minimize leakage loss of a combustion gas and enhance the efficiency of an engine by means of the formation of blow seals for generating countercurrent movement that is opposite to the main movement of the combustion gas in a gap portion between a casing and blades of a turbine. The blade tip sealing apparatus is provided with: a casing (22) for guiding the movement of a combustion gas; a plurality of blades (26) connected to a rotating shaft (20) inside the casing (22); a shroud (28) provided so as to cover the front end portions of the blades (26); a plurality of blow seals (30) formed on the outer peripheral side along the entire periphery of the shroud (28); and a rotating device for variably adjusting the inclination angles of the blow seals (30) on the basis of the rotational speed of the blades (26).

Description

Blade tip sealing device of gas turbine

TECHNICAL FIELD The present invention relates to a blade tip sealing device of a gas turbine, and more particularly, to the loss of combustion gas leakage through the generation of a countercurrent flow in a gap between the casing and the blade of the turbine in a direction opposite to the main flow direction of the combustion gas. Blade tip sealing device for gas turbines to reduce the risk of blade breakage due to rubbing as well as reduce the risk of blade breakage due to securing adequate clearance between turbine casing and blades It is about.

In general, a gas turbine device is a kind of turbomachine that burns fuel by using high pressure compressed air and generates rotational power by using high temperature / high pressure combustion gas discharged during combustion.

The gas turbine of such a configuration has a compressor that sucks external air and compresses it to high pressure, a combustor that mixes and burns the air compressed at high pressure through the compressor, and a high / high pressure combustion gas discharged after combustion through the combustor. It can be divided into a turbine that generates the rotational force required for the generation of energy from the flow.

In addition, since the leakage of the combustion gas discharged directly to the outside without passing through the blade in the turbine has a significant part on the overall efficiency of the engine, countermeasures are very important. In one example, Figure 1 shows the leakage loss of the flow generated in a conventional gas turbine.

Referring to FIG. 1, the turbine 71 includes a blade 75 that rotates at a high speed with respect to the rotating shaft 73 through a flow of combustion gas, and the leakage of the flow is at the free end of the blade 75. And at the gap site between the casing 77. That is, the flow of the combustion gas discharged after combustion is largely the main flow (C) discharged through the blade 75, the leakage flow (D) toward the gap portion between the blade 75 and the casing 77. Can be distinguished.

In this case, since the leakage flow D of the combustion gas acts as a large factor in determining the efficiency of the engine, the shroud 79 located at the free end of the blade 75 has an outer surface of the casing 77. The labyrinth seal 81 protruding toward the inner circumferential surface is integrally formed. In addition, a honeycomb seal 83 is provided on the inner circumferential surface of the casing 77 to set a proper gap between the labyrinth seal 81.

As such, the installation state of the labyrinth seal 81 on the blade 75 may be more clearly understood with reference to FIG. 2. That is, the labyrinth seal 81 protrudes from the outer surface of the shroud 79 in a vertical direction to secure an appropriate gap between the honeycomb seals 83.

By the way, in the conventional turbine 71, the gap secured by the space between the labyrinth seal 81 and the honeycomb seal 83 is a shroud 79 and a fixed member including a blade 75 that rotates at high speed In addition to the pure function of preventing damage to parts by preventing direct contact between the honeycomb seals 83 of the casing 77 corresponding to the corresponding casings 77, excessive combustion gas leakage may be caused when a clearance greater than or equal to a gap is set to increase the overall efficiency of the engine. Because of the adverse effects that adversely affects at the same time, ensuring adequate clearance is a very important factor in the design of gas turbines. For example, if the gap is set too narrow, it may contribute to the engine efficiency by reducing the leakage loss in the initial operation of the gas turbine, but rubbing due to thermal deformation between the rotor and the stator as the engine operating time increases This increases the risk of the occurrence of P, which in extreme cases results in damage to the parts due to contact.

For example, in the squealer type blade 75 without the labyrinth seal 81, the leakage flow D is accompanied through a gap portion formed between the casing 77 and the engine efficiency. On the other hand, the blade 75 with the labyrinth seal 81 can reduce the leakage flow (D) generated in the gap portion with the casing 77, but with respect to the structural stability. In addition to the problems, there are limitations in considering the life of the parts.

That is, when one or more labyrinth seals 81 are formed at the free end of the blade 75 in the conventional turbine 71, the aerodynamic performance could be improved by lowering the leakage degree of the combustion gas. Due to the additional setting of the labyrinth seal 81 corresponding to the heavy part at the free end of the member rotating at high speed due to the characteristics of), the problem of durability and consequently durability is to offset the expected effect of improved aerodynamic performance. Since it acts as a sufficient factor, there is a need for a countermeasure in a different direction to the leakage of combustion gas. In particular, the countercurrent flow accompanying the setting of the labyrinth seal 81 exhibits a flow characteristic corresponding to a kind of vortex that is insufficient to completely block the leakage flow D, and thus, the method of this method is further required.

Accordingly, the present invention has been made in view of the above-mentioned matters, and the combustion gas is formed through the formation of a blow seal for generating a counterflow flow opposite to the main flow direction of the combustion gas at the gap between the casing and the blade of the turbine. It is an object of the present invention to provide a blade tip sealing device of a gas turbine that can improve the energy efficiency of an engine by minimizing leakage loss.

In addition, the present invention lowers the risk of breakage of the blades due to rubbing by securing a proper gap between the casing and the blade of the turbine by forming the blow seal, thereby delaying the blade replacement cycle as well as extending the life of the blade accordingly It is an object of the present invention to provide a blade tip sealing device of a gas turbine capable of pursuing economic feasibility.

The present invention for achieving the above object is a casing configured to guide the flow of combustion gas, a plurality of blades coupled to the rotating shaft in the casing, a shroud is installed to surround the front end of the blade, and the shroud Disclosed is a blade tip sealing apparatus of a gas turbine having a plurality of blow seals formed along a circumference to produce a counter flow in a direction opposite to a main flow of combustion gas.

In the present invention, the blow seal is formed of at least one of the shape of the rectangular cross section or the various cross-sectional shape, the wedge shape of the horizontal cross section, the wedge shape of the horizontal and vertical cross section, and the airfoil cross section shape on the outer surface of the shroud. .

In the present invention, the blow seal is formed to have the same pitch at the inlet and the outlet based on the direction of the counterflow flow, or different pitches at the inlet and the outlet based on the direction of the counterflow flow. It is formed to have.

In the present invention, the blow seal is arranged by varying the inclination angle with respect to the shroud.

The present invention further includes a flow guide vane protruding outwardly from the outer surface of the blow seal to the outside, wherein the flow guide vane is formed in an inclined upward direction from the base of the blow seal toward the free end.

In addition, the flow guide vane is formed as a linear outlet extension or streamlined outlet extension that extends the separation distance from the inlet to the outlet relative to the formation direction of the reflux flow.

In addition, when the flow guide feather is a streamlined outlet expansion type, it is formed in a concave upward shape or a convex upward shape from the base of the blow seal toward the free end.

In addition, the flow guide feather is a first flow guide portion formed in the form inclined upward toward the free end from the base of the blow seal, and inclined downward toward the base of the outlet side of the blow seal from the first flow guide portion It consists of a second flow guide formed in the form, the first flow guide and the second flow guide is formed at a distance apart.

The present invention is a casing configured to guide the flow of the combustion gas, a plurality of blades coupled to the rotating shaft in the casing, a shroud is installed to surround the front end of the blade, the shroud is formed in a plurality along the perimeter around the combustion gas A blade tip sealing device for a gas turbine having a blow seal that generates a counter flow in a direction opposite to the main flow of and a turning facility for variably adjusting the inclination angle of the blow seal according to the rotational speed of the blade.

In the present invention, the turning device is a hinge shaft rotatably supporting the blow seal, a pressure chamber for rotatably receiving the hinge shaft therein, a rotor coupled to the hinge shaft and divides the inside of the pressure chamber And an operating facility for providing an operating pressure inside the pressure chamber partitioned by the rotor.

In the present invention, the operation equipment is a plurality of pressure pipes formed to be in communication with the space divided by the rotor in the pressure chamber, the direction control valve for controlling the supply of the operating pressure through the pressure pipe, It includes a hydraulic pump for supplying a working pressure into the pressure chamber, a pressure control valve for regulating the operating pressure supplied to the directional control valve.

The present invention further includes a rotation speed detection unit for detecting a rotation speed of the blade, and a control unit for controlling the operation of the direction control valve and the pressure control valve according to the rotation speed detected from the rotation speed detection unit. It further comprises a relief valve for cutting off the operating pressure supplied, the relief valve is installed between the direction control valve and the pressure control valve.

The present invention can minimize the leakage loss of the combustion gas through the generation of a return flow in the gap between the casing and blade tip of the gas turbine in the direction opposite to the main flow direction of the combustion gas, thereby improving the overall energy efficiency of the engine. Will provide a beneficial effect.

In particular, the present invention optimizes the flow at the surface of the blow seal with the application of various changes in the shape of the blow seal, such as the application of various cross-sectional shapes, which are optimized in generating a counter flow opposite the main flow direction at the gap between the casing and the blade. Leakage flow can be minimized by providing fluidity in a specific direction due to the addition of protrusions for guiding in the direction of, and above all, the angle of inclination that takes into account the rotational speed of the turbine in setting the blow seal for generating the counterflow flow Proper modifications and therefore optimum control can be implemented simultaneously, minimizing losses due to combustion gas leakage.

In addition, the present invention extends the endurance life of the parts by ensuring a minimum clearance that can completely eliminate the risk of rubbing caused by thermal deformation over the operating time of the engine in the gap between the casing and the blade. And the economical effect of delaying the blade replacement cycle as much as possible.

1 is a partial cross-sectional view for explaining the leakage loss of flow between a blade and a casing of a conventional gas turbine.

FIG. 2 is a perspective view schematically illustrating an installation state of a labyrinth seal provided in the turbine blade illustrated in FIG. 1 to reduce leakage loss generated between the casing and the casing.

3 is a diagram schematically showing the overall configuration of a gas turbine engine to which an embodiment of the present invention is applied.

Figure 4 is a partial cross-sectional view showing the main components in the blade tip sealing device of the gas turbine according to an embodiment of the present invention.

FIG. 5 is a perspective view schematically illustrating an installation state of a blow seal for reducing leakage loss generated between the casing in the turbine blade shown in FIG. 4.

6 through 9 are plan views partially illustrating various modified forms of the cross-sectional shape of a blow seal according to various embodiments of the present disclosure.

10 to 13 are side views partially showing various modifications to the side shape of the blow seal as various embodiments of the present invention.

FIG. 14 is a perspective view partially showing the main components of a turning device for variably adjusting the inclination angle of the blow seal with respect to the tip of the blade as another embodiment of the present invention.

FIG. 15 is a view showing an overall configuration including a hydraulic circuit in the turning facility shown in FIG. 14.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 3, the gas turbine engine includes an intake unit 10 that sucks outside air, a compressor 12 that compresses the outside air sucked through the intake unit 10 to a high pressure, and the compressor 12. Combustor 14, which mixes air compressed at high pressure with fuel and then burns it to produce hot / high pressure combustion gas, and generates energy from the high temperature / high pressure combustion gas flow combusted through the combustor 14. Turbine 16 for generating the required rotational force, exhaust unit 18 for discharging the combustion gas passed through the turbine 16 to the outside, and the compressor 12 and the turbine 16 in conjunction with the generator (not shown) It is configured to include a rotating shaft 20 for driving.

The intake unit 10 serves to guide the compressor 12 to the outside air introduced as a portion for receiving intake air from the outside. In this case, the inlet of the intake portion 10 is formed in the shape of a bellmouth (bellmouth) is configured to allow a greater amount of outside air to flow.

The compressor 12 serves to pressurize the suction air introduced through the intake unit 10 and supply the compressed air to the combustor 14. To this end, the compressor 12 includes a guide vane for guiding the flow direction of intake air, a rotor blade disposed at the rear of the guide vane and rotating together with the rotation shaft 20, and a stator vane disposed at the rear of the rotor blade. In this case, the compressor 12 alternately installs the rotor blades and the stator vanes on the rotation shaft 20, and arranges the rotor blades and the stator vanes in a plurality of rows along the axial direction of the rotation shaft 20, respectively. It consists of a multi-stage facility that gradually pressurizes the air being sucked in several stages to convert it into a high pressure state.

The combustor 14 is disposed radially over the entire circumference of the flow path of the air compressed to high pressure via the compressor 12 to generate a high temperature / high pressure combustion gas according to the combustion of a mixture of air and fuel. Do this. In one example, the combustor 14 is composed of a can type, an annular type and a can-annular type.

The turbine 16 is a facility that rotates by the flow of the high temperature / high pressure combustion gas provided through the combustor 14 to generate power required for driving the generator, and similarly to the compressor 12. The rotor blades and the stator vanes are arranged in multiple rows, respectively, along the axial direction of the rotation shaft 20. That is, the turbine 16 alternately installs the rotor blades and the stator vanes on the rotation shaft 20, respectively, and rotates the rotor blades and the stator vanes in a plurality of rows in the axial direction of the rotation shaft 20, respectively. It arrange | positions, and converts the energy which a combustion gas has into mechanical energy of a rotation direction.

The exhaust unit 18 serves to discharge the combustion gas that provides the rotational force to the turbine 16 to the outside. In this case, the exhaust unit 18 is configured to be in communication with a purification facility for post-treatment of exhaust gas in consideration of environmental problems such as air pollution. The rotating shaft 20 is a shaft member including the compressor 12 and the turbine 16 to rotate together by interlocking the generator, it may be composed of a single shaft member or a plurality of shaft members.

For reference, an arrow denoted by reference numeral A in FIG. 3 denotes a flow direction of intake air introduced into the gas turbine through the intake unit 10, and an arrow denoted by reference numeral B denotes the compressor 12. Means the flow direction of the compressed air is compressed to high pressure through, the arrow denoted by the reference C is burned through the combustor 14 and then rotates the turbine 16 and then outward through the exhaust (18) It means the flow direction of discharged combustion gas.

4 is a partial cross-sectional view showing the main components of the blade tip sealing device of the gas turbine according to an embodiment of the present invention, Figure 5 is to reduce the leakage loss generated between the casing in the turbine blade shown in FIG. It is a perspective view schematically showing the installation state of the blow seal for.

Referring to FIGS. 4 and 5, respectively, the turbine 16 has a honeycomb seal 24 for hermeticity with the free end of the blade front end corresponding to the tip of the blade 26 in the casing 22. Install). That is, the honeycomb seal 24 is provided in a form surrounding the tip portion of the blade 26 from the outside over the entire circumference of the inner circumferential surface of the casing 22. At this time, a proper gap is secured between the honeycomb seal 24 and the tip portion of the blade 26 to prevent damage to the member due to contact.

The blade 26 generates a countercurrent flow E directed in a direction opposite to the main flow C of the combustion gas provided from the combustor 14, whereby the inner circumferential surface of the casing 22 or the honeycomb seal ( A separate tip sealing device is provided to reduce the efficiency loss of the engine due to the leakage flow (D) of the combustion gas resulting from the formation of the gap between 24 and 24. At this time, the degree of the return flow (E) generated by the tip sealing device is preferably adjusted to be within a range that does not impair the overall efficiency of the engine.

A part of the main flow C of the combustion gas flows in part between the shroud 28 and the honeycomb seal 24 along the rotational direction R. In the related art, the inflow is more than a predetermined amount by the labyrinth seal 81. Blocked. In the present invention, the labyrinth seal is eliminated and the flow of some of the incoming combustion gas is diverted to the countercurrent flow E by the tip sealing device, thereby preventing the leakage flow D of the combustion gas.

That is, the tip sealing device is for generating a countercurrent flow (E) in a direction opposite to the main flow (C) of the combustion gas from the combustor 14 toward the turbine 16, the countercurrent flow of the combustion gas ( E) may be generated at the gap between the casing 22 and the blade 26, that is, between the honeycomb seal 24 installed on the inner circumferential surface of the casing 22 and the tip portion of the blade 26. To be.

To this end, the tip sealing device is composed of a blow seal 30 formed on the outer peripheral surface of the outer surface of the annular shroud 28 that is installed over the entire circumference of the blade 26. In this case, the blow seal 30 is provided in a plurality of quantities at intervals of equal intervals or uneven intervals over the outer circumference of the outer surface of the shroud 28. In addition, the blow seal 30 has a predetermined angle of inclination with respect to the virtual reference line L (see FIG. 5) along the circumferential direction of the shroud 28 of the virtual reference line facing the circumferential direction of the turbine blade 26. It is arranged to be. In particular, the inclination angle of the blow seal 30 may be generated in the countercurrent flow E in a direction opposite to the main flow C of the combustion gas based on the rotation direction R of the blade 26. Is set. That is, the countercurrent flow E of the combustion gas by the blow seal 30 corresponds to the incidental flow of the combustion gas generated from the rotation of the blade 26 by the main flow C of the combustion gas. It is created in the reverse direction along the gap between the blow seals 30 at the gap portion between the honeycomb seals 24.

In summary, the tip sealing device receives a return flow flow E of the combustion gas from the combustor 14 in a direction opposite to the main flow C of the combustion gas from the combustor 14 to the turbine 16. It consists of a blow seal 30 which can be generated between the blades 26, that is, between the honeycomb seal 24 installed on the inner circumferential surface of the casing 22 and the tip portion of the shroud 28. That is, after a part of the main flow C of the combustion gas discharged between the blades 26 is guided between the shroud 28 and the honeycomb seal 24, the countercurrent flow E is formed in the direction of the arrow of FIG. 5. In order to achieve this, it is preferable that the inclination angle formed by the virtual reference line L and the blow seal 30 is an acute angle (to be described later).

6 to 9 are various embodiments of the present invention, which are plan views partially illustrating various modified forms of the cross-sectional shape of the blow seal (the overlapping of the arrangement or the inclination angle of the blow seal in describing the embodiment may be repeated). Description will be omitted).

Referring to FIG. 6, when the blow seal 30 is viewed from above the outer circumferential surface of the shroud 28, the planar shape is a polygonal shape including a triangle and a quadrangle, or an elliptical shape or one side of the elliptical pointed deformation shape or the like. The cross-sectional shape is based on a horizontal direction parallel to the tangential direction on the outer surface of the outer surface is composed of a plurality of members that are set to a rectangular plate form or a variety of cross-sectional shape. Referring to FIG. 6, a plurality of blow seals 30 may be provided, the planar shape may have a quadrangular shape, and a block shape having a predetermined thickness and width. In this case, the plurality of blow seals 30 formed of the rectangular cross section or the members having various cross-sectional shapes are disposed at equal intervals or uneven intervals on the outer circumferential surface of the outer surface of the shroud 28 (hereinafter referred to as the reference line of FIG. Since the right side of the blow seal 30 is the inflow direction of the countercurrent flow E based on (L), it is defined as an inlet, and the left side of the blow seal 30 is the countercurrent flow E based on the reference line L. Since it is the outflow direction of, it is defined as the outlet part).

That is, the blow seal 30 having the rectangular cross section or the various cross-sectional shapes is formed at the inlet portion (the right side of the drawing reference), that is, the portion corresponding to the inlet portion of the blow seal 30 based on the direction of the countercurrent flow E. The intervals (pitch, P) and the intervals (pitch, P) of the portions corresponding to the outlet portions (the left side of the reference drawing) of the blow seal 30 may be arranged at equal intervals. On the other hand, the blow seal 30 having a rectangular cross section or various cross-sectional shapes has different inlet spacing (pitch, P) and outlet spacing (pitch, P) in order to minimize the leakage flow D for the combustion gas. It may be set to be arranged at uneven intervals.

In addition, the blow seal 30 having a rectangular cross section or various cross-sectional shapes is arranged to have a predetermined inclination angle with respect to the virtual reference line L along the circumferential direction of the shroud 28 in order to minimize the leakage flow D of the combustion gas. It is desirable to be.

That is, the inclination angle A may be set to an optimal state with respect to the shroud 28 reference line L. Preferably, the inclination angle A may be an acute angle of 45 degrees or less. have. The plurality of blow seals 30 may be arranged to have the same inclination angle with respect to the reference line L, or may be arranged to have different inclination angles between neighboring blow seals 30. For example, in the shroud 28 The inclination angles A of the blow seals 30 with respect to each other are set to be the same or different from each other. The adjustment of the inclination angles and the arrangement of the blow seals 30 are the results of experiments or numerical analysis on the countercurrent flow E. According to the optimum shape can be found in advance.

Referring to FIG. 7, the blow seal 30 has a cross section based on a horizontal direction in which the plane shape is parallel to the tangential direction on the outer surface of the shroud 28 when viewed from above the outer circumferential surface of the shroud 28. The shape of the may be composed of a plurality of members that are set in the form of a triangular wedge (wedge) is gradually reduced from one side to the other side. The blow seal 30 is provided in plurality, and is in the form of a block having a predetermined thickness. At this time, the plurality of blow seals 30 formed by the member of the wedge cross section is disposed on the outer peripheral surface of the shroud 28 at equal intervals or uneven intervals.

That is, the interval (pitch, P) of the portion corresponding to the inlet portion of the blow seal 30 and the interval (pitch, P) of the portion corresponding to the outlet portion of the blow seal 30 are respectively set at equal intervals. Can be. Alternatively, the blow seal 30 may be arranged at different intervals by setting the inlet gap (pitch, P) and the outlet gap (pitch, P) differently in order to minimize the leakage flow D for the combustion gas. have.

Further, the blow seal 30 is preferably arranged to have a predetermined inclination angle with respect to the virtual reference line L along the circumferential direction of the shroud 28 in order to minimize the leakage flow D of the combustion gas. The wedge-shaped blow seal 30 of the horizontal section corresponds to the spacing (pitch, P) and the outlet portion (left of the drawing reference) corresponding to the inlet (right of the drawing) based on the direction of the return flow E. The intervals (pitch, P) of the portions to be set are set at equal intervals, respectively. On the contrary, the wedge-shaped blow seal 30 sets the gap (pitch, P) of the inlet part and the gap (pitch, P) of the outlet part at different intervals to minimize leakage flow D of the combustion gas. It may be arranged. In addition, the wedge-shaped blow seal 30 of the horizontal section may be arranged to set the inclination angle (A) to the optimal state with respect to the shroud 28 in order to minimize the leakage flow (D) of the combustion gas. For example, the inclination angles A of the blow seals 30 with respect to the shroud 28 are set to be the same or different from each other. In particular, in the wedge-shaped blow seal 30, the wedge-shaped cross-sectional direction has a leading edge at the inlet of the counterflow flow E, the other end of which is relatively wider than one end of the wedge shape. Arranging the trailing edge opposite to the leading edge at the outlet of the reflux flow E while placing it at the inlet of (E), or conversely placing the trailing edge at the inlet of the reflux flow E It is also possible to arrange the leading edge at the outlet of the countercurrent flow E.

Referring to FIG. 8, a plurality of blow seals 30 are provided, and when the top surface of the shroud 28 is viewed from above, the shape of the plane is tangential to the outside of the shroud 28. It may have a triangular wedge shape in which the shape of the cross section is gradually reduced with respect to the horizontal direction parallel to the direction, and has a tetrahedral shape in which the bottom surface is a wedge shape when viewed in the direction of the virtual reference line L. . It consists of a plurality of members set in the form of a triangular wedge in which the cross-sectional area is gradually reduced on the basis of the same vertical direction as the forming direction of the blade 26. At this time, the plurality of blow seals 30 formed by the member of the wedge cross section is disposed on the outer circumferential surface of the shroud 28 at equal intervals or uneven intervals on the outer surface.

The spacing and arrangement of the blow seals 30 are the same as in the embodiment of FIG. 7, and thus detailed descriptions thereof will be omitted.

That is, the wedge-shaped blow seal 30 of the horizontal and vertical cross-sections correspond to the interval between the inlet portion (the right side of the drawing) and the outlet portion (the left side of the drawing) based on the direction of the return flow E. The intervals (pitch, P) of the portions to be set are set at equal intervals, respectively. On the contrary, the wedge-shaped blow seal 30 sets the gap (pitch, P) of the inlet part and the gap (pitch, P) of the outlet part at different intervals to minimize leakage flow D of the combustion gas. It may be arranged. In addition, the wedge-shaped blow seal 30 of the horizontal and vertical cross-section may be arranged by setting the inclination angle (A) to the optimal state with respect to the shroud (28) in order to minimize the leakage flow (D) of the combustion gas. have. For example, the inclination angles A of the blow seals 30 with respect to the shroud 28 are set to be the same or different from each other. In particular, in the wedge-shaped blow seal 30, the cross-sectional direction of the wedge shape is provided with a trailing edge at the outlet of the countercurrent flow E while arranging a leading edge at the inlet of the countercurrent flow E. It is also possible to arrange the trailing edge or, conversely, to arrange the trailing edge at the inlet of the countercurrent flow E and at the outlet of the countercurrent flow E.

Referring to FIG. 9, a plurality of blow seals 30 are provided, and when the outer circumferential surface of the shroud 28 is viewed from above, the shape of the plane is tangential to the outer surface of the shroud 28. It consists of a plurality of members set in the form of airfoils whose shape of the cross section is gradually reduced with respect to the horizontal direction parallel to the direction. It can have At this time, the plurality of blow seals 30 formed by the member of the airfoil cross section is disposed on the outer circumferential surface at the outer surface of the shroud 28 at equal intervals or uneven intervals.

Further, the blow seal 30 is preferably arranged to have a predetermined inclination angle with respect to the virtual reference line L along the circumferential direction of the shroud 28 in order to minimize the leakage flow D of the combustion gas. The blow seal 30 of the cross-sectional shape of the airfoil corresponds to the interval (pitch, P) and the outlet portion (left side of the drawing) corresponding to the inlet portion (right side of the drawing) based on the direction of the return flow E. It arrange | positions by setting the space | interval (pitch, P) of the site | part to make at equal interval. On the contrary, the airfoil type blow seal 30 sets the gap (pitch, P) of the inlet part and the gap (pitch, P) of the outlet part differently to minimize the leakage flow D for the combustion gas. It may be arranged as. In addition, the airfoil type blow seal 30 may be disposed by setting the inclination angle A to an optimal state with respect to the shroud 28 in order to minimize the leakage flow D of the combustion gas. For example, the inclination angles A of the blow seals 30 with respect to the shroud 28 are set to be the same or different from each other.

In particular, in the airfoil type blow seal 30, the cross-sectional direction, which is wider than the other end of the airfoil type, has a leading edge at the inlet of the counterflow flow E. Placing a trailing edge opposite the leading edge at the outlet of the reflux flow E while placing it at the inlet of E), or conversely placing a trailing edge at the inlet of the reflux flow E It is also possible to arrange the leading edge at the outlet of the reflux flow E.

In summary, the blade tip sealing apparatus of the gas turbine according to the present invention, as shown in each of FIGS. 6 to 9, through the generation of the return flow (E) by the combustion gas according to the formation of the blow seal (30) Engine efficiency is minimized by branching from the main flow C of combustion gas and minimizing the degree of leakage flow D towards the gap between the honeycomb seal 24 of the casing 22 and the tip of the blade 26. Can contribute to improvement.

Referring to FIG. 10, the blow seal 30 defines a flow direction with respect to the countercurrent flow E of the combustion gas with a gap portion with the inner circumferential surface of the honeycomb seal 24 located on the inner circumferential surface of the casing 22. A guiding flow guide vane 32 protruding from the outer surface toward the outside for guiding therefrom, the arrangement direction of which is from the base toward the shroud 28 at the blow seal 30; 22 is set in the form of inclined upward toward the free end toward the honeycomb seal 24. In particular, the flow guide vane 32 is formed in at least one of the two sides of the blow seal 30.

In this case, the flow guide vanes 32 are disposed in plural to be spaced apart from the surface of the blow seal 30 at a predetermined interval. In particular, the flow guide feather 32 is an outlet portion (right side of the drawing) from an inlet portion (right side of the drawing) based on the direction of formation of the return flow E by the combustion gas according to the formation of the blow seal 30. It is arranged in the form of extending the separation distance between each other toward. In this case, the overall shape of the flow guide feather 32 is in the form of a straight line.

Accordingly, the distribution of the counterflow flow E set by the linear outlet extension flow guide blade 32 can be uniformly dispersed and diffused from the inlet to the outlet of the blow seal 30, so that the combustion gas Branching from the main flow C of the can further contribute to minimizing the degree of leakage flow D towards the gap between the honeycomb seal 24 of the casing 22 and the tip of the blade 26. .

Referring to FIG. 11, the flow guide vane 32 has the same arrangement as the flow guide vane 32 shown in FIG. 10. However, each of the flow guide vanes 32 is formed to have a curved curvature in a concave upward shape from the base of the blow seal 30 toward the honeycomb seal 24 of the casing 22. Even in the case of the streamlined outlet extended flow guide blade 32 set in such a shape, an effect similar to the guide blade shown in FIG. 10 can be realized, and above all, the honeycomb seal 24 of the casing 22 and It is possible to provide an effect that can further promote the return flow (E) toward the gap portion between the tip of the blade 26.

Referring to FIG. 12, the flow guide feather 32 has the same arrangement as the flow guide feather 32 shown in FIGS. 10 and 11, respectively. In particular, each of the flow guide vanes 32 is upwardly convex toward the honeycomb seal 24 of the casing 22 from the base of the blow seal 30 as compared to the flow guide vanes 32 shown in FIG. 11. It is formed to have a curved curvature. Even in the case of the streamlined outlet type extended flow guide feather 32 set in such a shape, an effect similar to that of the guide feather shown in FIGS. 10 and 11 can be realized, and above all, the honeycomb seal of the casing 22. It will provide the effect of promoting the countercurrent flow E toward the gap portion between the 24 and the tip of the blade 26 as well as the countercurrent flow E towards the outlet of the blow seal 30 together. It becomes possible.

Referring to FIG. 13, the flow guide vanes 32 are different from the flow guide vanes 32 shown in FIGS. 10 to 12, respectively, at the base of the blow seal 30 at the inlet of the blow seal 30. The first flow guide portion 32a set in an inclined manner upward toward the honeycomb seal 24 of the casing 22 and the outlet portion side of the blow seal 30 from the first flow guide portion 32a. It consists of the 2nd flow guide part 32b set in the form inclined downward toward the base part. That is, FIG. 13 corresponds to a blow seal 30 with a streamlined composite flow guide vane 32.

At this time, the first flow guide portion 32a and the second flow guide portion 32b are formed to have a predetermined distance. Accordingly, the initial flow of the counterflow flow E according to the formation of the first flow guide portion 32a is a gap portion between the honeycomb seal 24 of the casing 22 and the tip of the blade 26. And the end flow of the counterflow flow E according to the second flow guide portion 32b to block the leakage flow D entering the gap portion. Can be set to contribute to blocking the initial entry of the leakage flow D towards the gap site.

FIG. 14 is a perspective view partially showing the main components of a turning device for variably adjusting the inclination angle of the blow seal with respect to the tip end portion of the blade, and FIG. 15 is a turning view shown in FIG. A diagram showing the overall configuration including the hydraulic circuit in the installation.

Referring to FIGS. 14 and 15, the blow seal 30 is returned by varying the inclination angle of the blow seal 30 with respect to the shroud 28 in response to the rotational speed of the blade 26. A turning device for freely controlling the degree of generation of the flow E is provided.

The pivoting facility is a hinge shaft (34) formed on the blow seal (30) to rotatably support the blow seal (30) to freely adjust the inclination angle of the blow seal (30) with respect to the shroud (28), A pressure chamber 36 accommodating the hinge shaft 34 therein and rotatably supporting the rotor shaft; and a rotor coupled to the hinge shaft 34 to divide the internal space of the pressure chamber 36 into an airtight state ( 38) and provide a separate working pressure to the airtightly divided space between the rotor 38 in the interior of the pressure chamber 36 to provide a separate working pressure of the rotor 38 within the pressure chamber 36. It is configured to include an operating facility for promoting the rotation of the hinge shaft 34 by implementing the rotation.

In this case, the hinge shaft 34 is formed at one lower end portion of the blow seal 30, and the pressure chamber 36 is disposed inside the shroud 28 so that the leakage flow D and the return flow E It is set to minimize the leakage space for). In addition, the pressure chamber 36 forms a stopper 36a protruding therein to limit the angle of rotation by the rotor 38, and the stopper 36a is formed at the shroud 28. It is set to correspond to a position defining an angle of inclination of the blow seal 30 with respect to. As a result, the rotation angle of the rotor 38 in the pressure chamber 36 can be limited to a range defined by the stopper 36a, so that the hinge shaft 34 with respect to the pressure chamber 36 The rotation angle is also dependently limited so that the inclination angle of the blow seal 30 with respect to the shroud 28 can be limited to a desired range.

In addition, the operation equipment is formed in the pressure chamber 36 in a communication space to the space divided by the rotor 38, a plurality of pressure pipe line 40 for the individual supply and discharge of the operating pressure, the In order to provide the supply of the working pressure using any one of the pressure pipes 40, the direction control valve 42, in which the port is switched, and the degree of the operating pressure supplied to the direction control valve 42 are appropriately adjusted. Pressure control valve 44 for the purpose, the relief valve 46 to cut off the supply of the operating pressure in the middle in case the operating pressure supplied through the pressure line 40 is excessive, and the pressure chamber 36 It is configured to include a hydraulic pump 48 for generating an operating pressure made through the pressure line 40 for the rotation of the rotor 38 within.

In this case, the pressure line 40 is formed to communicate with the inside of the pressure chamber 36 via the shroud 28 via the rotating shaft 20 and the blade 26. In addition, in the operation equipment, the rest of the configuration except the pressure line 40 is installed in a position that can exclude the interference with the operating element, such as the blade 26 including the rotating shaft 20, of course. In particular, the relief valve 46 is installed in the pressure line 40 located between the directional control valve 42 and the pressure control valve 44 so that the supply pressure provided from the pressure control valve 44 is excessive. In this case, the protection of the operating equipment is performed.

On the other hand, the turning device is a control unit 50 for variably adjusting the inclination angle of the blow seal 30 with respect to the blade 26 in accordance with the rotational speed of the blade 26, and the control unit 50 It further comprises a rotational speed detection unit 52 for detecting and providing a drive speed of the turbine 16 or the blade 26. Reference numeral 54 in the figure corresponds to an oil pan for providing hydraulic oil to the hydraulic pump 48.

In this case, the control unit 50 outputs an appropriate operation signal for the solenoid of the directional control valve 42 according to the driving speed of the turbine 16 input through the rotational speed detection unit 52. Since the operating pressure is limited to any one of the two inner spaces that are hermetically partitioned about the rotor 38 within the 36, the rotation of the hinge shaft 34 can be realized.

In addition, the control unit 50 is the operating pressure of the operating pressure provided to the pressure chamber 36 via the direction control valve 42 in accordance with the drive speed of the turbine 16 input through the rotation speed detection unit 52. The degree can be adjusted appropriately, which is realized by a series of pressure controls for the pressure control valve 44. For example, the controller 50 may adjust the operation signal provided to the solenoid of the pressure control valve 44 according to the selection of the duty value or control the linear output value in a proportional control manner.

Hereinafter will be described in detail the operation of the blade tip sealing device of the gas turbine according to an embodiment of the present invention.

The high temperature / high pressure combustion gas flow combusted through the combustor 14 rotates the blade 26 of the turbine 16 to contribute to the generation of energy, and the casing 22 and the A leakage flow D through the gap between the shrouds 28 located at the free end of the blade 26.

In this case, the leakage flow D of the combustion gas is reduced by the countercurrent flow E formed by the blow seal 30. That is, as shown in FIGS. 6 to 9, the blow seal 30 having various cross-sectional shapes is set in a direction opposite to the main flow C of the combustion gas according to the rotation of the blade 26. The flow E is formed, and the generation of the countercurrent flow E enables to minimize the leakage flow D generated at the gap portion between the casing 22 and the shroud 28.

For example, since the plane of the rectangular cross section shown in FIG. 6 has a rectangular shape, the blow seal 30 is disposed in plural on the outer surface of the shroud 28 at equal intervals or unequal intervals over the entire circumference. In the space between the blow seals 30, the countercurrent flow E of the combustion gas set in a direction opposite to the main flow C of the combustion gas enters the gap portion between the casing 22 and the shroud 28. Thus, it is possible to contribute to minimizing the degree of leakage flow D directly discharged to the exhaust 18 without passing through the blade 26 of the turbine 16.

In addition, in the case of the wedge-shaped blow seal 30 in which the plane of the horizontal cross section shown in FIG. 7 is wedge-shaped, the same as that of the blow seal 30 of the square cross section of FIG. In generating the counterflow flow E which is formed in the direction of the flow, the space between the blow seals 30 is arranged through the arrangement of the trailing edge at the outlet of the flow together with the arrangement of the wide leading edge at the inlet of the flow. By increasing the initial velocity of the incoming combustion gas it can be further contributed to minimizing the leakage flow (D). In addition, in the wedge-shaped blow seal 30 of the horizontal section, when the leading edge, which is the wide end, and the trailing edge opposite to the leading edge, are arranged oppositely, the final velocity of the combustion gas toward the outlet of the flow is increased. As a result, the initial entry of the leakage flow D toward the gap portion between the casing 22 and the shroud 28 may be blocked at the source, thereby contributing to improving the efficiency of the engine.

In addition, the wedge-shaped blow seal 30 of the horizontal and vertical cross-section, wherein the planar shape shown in FIG. Like the blow blow 30, it can contribute to minimizing the leakage flow D towards the gap between the casing 22 and the shroud 28, in particular the vertical cross-sectional area of each blow seal 30 Through the change of the velocity and pressure of the return flow (E) according to the height position of the gap portion can be changed to provide a more improved effect to minimize the leakage flow (D).

In addition, the airfoil-type blow seal 30 illustrated in FIG. 9 generates the degree of generation of the countercurrent flow E formed through the effective arrangement of the curved portions based on the rotation direction R of the blade 26. By maximizing to reduce the leakage flow (D) through the gap between the casing 22 and the shroud 28 as much as possible can greatly contribute to improving the efficiency of the engine.

On the other hand, the blow seal 30 having a variety of side shapes as shown in Figure 10 to 13 through the formation of the flow guide blade 32 protruding toward the outside for the countercurrent flow (E) Directionality can also be adjusted, thereby contributing to reducing leakage flow D through the gap between the casing 22 and the shroud 28.

For example, as shown in FIG. 10, a straight outlet extended flow guide vane 32 extending the separation distance toward the outlet of the counterflow flow E is flowed back toward the outlet from the inlet of the blow seal 30. Since the distribution of the flow E can be uniformly dispersed and diffused, the leakage flow D through the gap portion between the casing 22 and the shroud 28 is branched from the main flow C of the combustion gas. Can be reduced.

In addition, as shown in FIGS. 11 and 12, the streamlined outlet extended flow guide vanes 32 which extend the separation distance toward the outlet of the countercurrent flow E are provided from the inlet of the blow seal 30. In addition to uniformly dispersing and diffusing the distribution of the counterflow flow E towards the outlet, the counterflow flow toward the outlet of the blow seal 30 together with the gap region between the casing 22 and the shroud 28 ( It will provide the effect of promoting E) together.

In addition, the streamlined composite flow guide vane 32 shown in FIG. 13 forms an initial flow direction of the countercurrent flow E through the formation of the first flow guide 32a to the casing 22 and the shroud ( 28) can be set toward the gap portion, thereby contributing to blocking the leakage flow (D) entering the gap portion, and through the formation of the second flow guide portion (32b) the late flow of the countercurrent flow (E) Can be set toward the outlet of the blow seal 30, thereby contributing to the original blocking of the initial entry of the leakage flow (D) toward the gap portion, thereby through the casing 22 and the shroud 28 It is possible to minimize the leakage flow (D) made through the gap portion of.

On the other hand, according to the present invention, the inclination angle of the blow seal 30 can be variably adjusted in conjunction with the rotational speed of the blade 26 using the turning facilities shown in Figs. And to further reduce the leakage flow D through the gap between the shroud 28 and the shroud 28.

That is, the controller 50 is in the pressure chamber 36 through port switching by the direction control valve 42 based on the rotation speed of the blade 26 detected through the rotation speed detection unit 52. Since it is possible to adjust the supply of the operating pressure provided to the divided space partitioned by the rotor 38 in the rotation angle of the hinge shaft 34, through which the blow seal for the shroud 28 ( The tilt angle of 30) can be adjusted arbitrarily.

In this case, the controller 50 may variably adjust the degree of the operating pressure supplied into the pressure chamber 36 through various pressure control of the pressure control valve 44, so that the inclination angle of the blow seal 30 In changing the direction of the countercurrent flow (E) generated according to the Figure it is possible to control more flexibly in accordance with the rotational speed of the blade (26).

As described above with reference to the accompanying drawings for the preferred embodiment of the present invention, the present invention is not limited by the above-described specific embodiments, those of ordinary skill in the art to which the present invention belongs Various modifications and variations are possible within the scope of the spirit and scope of the present invention as set forth below.

In particular, in the preferred embodiment of the present invention, the blow seal has been described on the basis of being formed on the outer surface of the shroud, but is formed directly with respect to the free end of the blade to be set between the honeycomb seal of the casing It may also be configured to create a reflux flow towards the gap site.

Claims

A casing configured to guide the flow of the combustion gas;

A plurality of blades coupled to a rotation axis in the casing;

A shroud installed to surround the tip of the blade; And

And a blow seal formed on the outer circumferential surface of the shroud along a circumference thereof to generate a return flow in a direction opposite to the main flow of the combustion gas.
The method according to claim 1,

The blow seal is a blade tip sealing device of the gas turbine, characterized in that when viewed from the outer circumferential surface from the outer surface of the shroud is a polygonal shape including a triangle and a quadrilateral in the shape of a rectangular cross section or a variety of cross-sectional shape .
The method according to claim 1,

The blow seal is a blade tip sealing device of the gas turbine, characterized in that the planar shape is formed in a wedge (wedge) when viewed from above the outer peripheral surface of the horizontal cross-section from the outer surface of the shroud.
The method according to claim 1,

The blow seal may be formed in a wedge shape having a wedge shape and a tetrahedral shape having a wedge shape when the outer seal surface of the horizontal and vertical sections is viewed from above on the outer surface of the shroud. Blade tip sealing device of gas turbine.
The method according to claim 1,

The blow seal is a blade tip sealing device of a gas turbine, characterized in that the plane of the plane shape when viewed from above the outer peripheral surface of the shroud in the cross-sectional shape of the airfoil.
The method according to any one of claims 2 to 5,

The blow seal is blade tip sealing device of the gas turbine, characterized in that formed in the same direction at the inlet portion and the outlet portion of the outlet flow flowing in the reflux flow based on the direction of the countercurrent flow.
The method according to any one of claims 2 to 5,

The blow seal may have different pitches at the inlet and the outlet, based on the direction of the counterflow, at the inlet of the counterflow and the outlet of the counterflow, based on the direction of the counterflow. Blade tip sealing device of a gas turbine, characterized in that formed.
The method according to any one of claims 2 to 5,

The blow seal is blade tip sealing device of the gas turbine, characterized in that arranged by varying the inclination angle with respect to the shroud.
The method according to claim 1,

The blade tip sealing device of the gas turbine, characterized in that it further comprises a flow guide blade protruding outwardly from the outer surface of the blow seal.
The method according to claim 9,

The flow guide blade is formed in the blade tip sealing device of the gas turbine, characterized in that the inclined upwardly toward the free end from the base of the blow seal.
The method according to claim 10,

The flow guide vane is a straight line that extends the separation distance from the inlet to the outlet based on the direction of the inlet portion and the outlet portion in which the counterflow flow is introduced based on the direction of the counterflow flow. Blade tip sealing device of the gas turbine, characterized in that the outlet portion of the expansion.
The method according to claim 10,

The flow guide vanes are streamlined to extend the separation distance from the inlet portion to the outlet portion based on the direction in which the inflow portion of the inflow flow flows in and the outlet portion in which the flow flow flows out, based on the direction of the upflow flow. Blade tip sealing device of the gas turbine, characterized in that the outlet portion of the expansion.
The method according to claim 12,

The flow guide feather is a blade tip sealing device of the gas turbine, characterized in that formed in the concave shape or upward convex shape toward the free end from the base of the blow seal.
The method according to claim 10,

The flow guide feather has a first flow guide portion formed in an inclined upward direction from the base of the blow seal toward the free end, and in a shape inclined downward from the first flow guide portion toward the base of the outlet side of the blow seal. Blade tip sealing device of the gas turbine, characterized in that consisting of the second flow guide is formed.
The method according to claim 14,

The first flow guide portion and the second flow guide portion blade tip sealing apparatus of the gas turbine, characterized in that formed at a distance apart.
A casing configured to guide the flow of the combustion gas;

A plurality of blades coupled to a rotation axis in the casing;

A shroud installed to surround the tip of the blade;

A blow seal formed on the outer circumferential surface of the shroud along a circumference thereof to generate a countercurrent flow in a direction opposite to the main flow of the combustion gas; And

And a turning device for variably adjusting the inclination angle of the blow seal according to the rotational speed of the blade.
The method according to claim 16,

The pivoting device may include a hinge shaft rotatably supporting the blow seal;

A pressure chamber rotatably accommodating the hinge shaft therein;

A rotor coupled to the hinge shaft and dividing an interior of the pressure chamber; And

A blade tip sealing device for a gas turbine, characterized in that it comprises an operating device for providing an operating pressure inside the pressure chamber partitioned by the rotor.
The method according to claim 17,

The operating equipment includes a plurality of pressure pipes formed to be in communication with the space divided by the rotor in the pressure chamber;

A directional control valve for regulating supply of operating pressure through the pressure line; And

And a hydraulic pump for supplying a working pressure into the pressure chamber.
The method according to claim 18,

The blade tip sealing device of the gas turbine further comprises a pressure control valve for adjusting the operating pressure supplied to the directional control valve.
The method according to claim 19,

A rotational speed detector for detecting a rotational speed of the blade; And

And a control unit for controlling the operation of the direction control valve and the pressure control valve according to the rotation speed detected by the rotation speed detection unit.
The method according to claim 19,

The blade tip sealing device of the gas turbine, characterized in that it further comprises a relief valve for blocking the operating pressure supplied to the pressure chamber.
The method according to claim 21,

The relief valve is a blade tip sealing device of the gas turbine, characterized in that installed between the direction control valve and the pressure control valve.