Turbine airfoil and gas turbine including the same

Abstract

To provide a turbine airfoil capable of realizing effective film cooling as compared with a conventional technology.SOLUTION: The airfoil of claim 1, further comprising an airfoil body including an outer wall forming an inner space, wherein the outer wall has cooling holes H communicating the inner space with an outer space of the airfoil body, and an inner surface of the outer wall defining the cooling holes H includes a first inner surface and a second inner surface defining an outer hole region H2 of the cooling holes H communicating with the outer space, A plurality of outer hole regions H2 may be formed to be spaced apart from each other, and the outer wall may include a partition section provided between two outer hole regions H2 adjacent to each other.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a turbine airfoil and a gas turbine including the airfoil, and more particularly to a turbine airfoil having a hole formed therein and a gas turbine including the airfoil. [Background technology]

[0002] A turbine is a mechanical device that uses the flow of compressible fluid such as steam or gas to generate rotational force through impulse or reaction force. Examples include steam turbines that use steam and gas turbines that use high-temperature combustion gases.

[0003] Among these, a gas turbine is broadly composed of a compressor, a combustor, and a turbine. The compressor is equipped with an air inlet for introducing air, and a number of compressor vanes and compressor blades are arranged alternately inside the compressor casing.

[0004] The combustor supplies fuel to the compressed air compressed by the compressor and ignites it with a burner to generate high-temperature and high-pressure combustion gas.

[0005] The turbine has a plurality of turbine vanes and turbine blades arranged alternately inside a turbine casing, and a rotor arranged to penetrate the center of the compressor, combustor, turbine, and exhaust chamber.

[0006] The rotor is rotatably supported at both ends by bearings. A plurality of disks are fixed to the rotor, and blades are connected to each disk. At the same time, a drive shaft of a generator or the like is connected to the end of the rotor facing the exhaust chamber.

[0007] Such gas turbines do not have a reciprocating mechanism like the pistons in four-stroke engines, so there are no parts that rub against each other like pistons and cylinders, which means that they consume very little lubricating oil, and the amplitude that is characteristic of reciprocating machines is greatly reduced, allowing for high-speed operation.

[0008] To briefly explain the operation of a gas turbine, air compressed by a compressor is mixed with fuel and burned to form high-temperature combustion gases, which are then injected into the turbine. The injected combustion gases pass through the turbine vanes and turbine blades, generating rotational force that rotates the rotor.

[0009] Meanwhile, according to the prior art, a film cooling method has been applied to cool turbine nozzles or turbine blades used in gas turbines. Film cooling refers to a method of protecting the surface of a turbine blade or the like exposed to high-temperature combustion gas by forming holes in the surface of the turbine blade or the like and injecting compressed air through the holes. Summary of the Invention [Problem to be solved by the invention]

[0010] SUMMARY OF THE INVENTION An object of the present invention is to provide a turbine airfoil that can achieve more effective film cooling than the prior art. [Means for solving the problem]

[0011] According to one aspect of the present invention to achieve the above object, there is provided a turbine airfoil including an airfoil body including an outer wall defining an internal space S, wherein cooling holes H are formed in the outer wall to communicate the internal space S with an external space of the airfoil body, and inner surfaces of the outer wall defining the cooling holes H include a first inner surface defining an inner hole region H1 of the cooling holes H that communicates with the internal space S and a second inner surface defining an outer hole region H2 of the cooling holes H that communicates with the external space, and the outer wall includes a partition section provided between two adjacent outer hole regions H2.

[0012] The inner surface further includes a third inner surface defining a connection hole region H3 connecting the inner hole region H1 and the outer hole region H2 of the cooling hole H, and the outer hole regions H2 may branch off from the connection hole region H3 at the boundary between the outer hole region H2 and the connection hole region H3.

[0013] In a cross section of the airfoil body taken along a first plane, the cross section includes the first inner surface, the second inner surface, and the third inner surface. In the cross section, the direction in which the third inner surface is bent relative to the first inner surface at a boundary between the first inner surface and the third inner surface located on one side of the cooling hole H may be different from the direction in which the third inner surface is bent relative to the first inner surface at a boundary between the first inner surface and the third inner surface located on the other side of the cooling hole H.

[0014] In a cross section of the airfoil body, which is obtained by cutting a region including the first inner surface, the second inner surface, and the third inner surface along a first plane, the outer hole regions H2 may be spaced apart from each other along an extension direction of the first plane.

[0015] In a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, a size of an angle βlat1 formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface located on one side of the cooling hole H may be equal to a size of an angle βlat2 formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface located on the other side of the cooling hole H.

[0016] In a cross section of the airfoil body obtained by cutting a region including the first inner surface, the second inner surface, and the third inner surface along a first plane, the second inner surface and the third inner surface may be located on the same plane.

[0017] In a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, angles βlat1 and βlat2 formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface may be greater than or equal to angles γlat1 and γlat2 formed by a line aligned with the second inner surface and a line aligned with the first inner surface at a boundary of the partition section.

[0018] In a cross section of the airfoil body, which includes the first inner surface, the second inner surface, and the third inner surface, cut along a first plane, a size of an angle γlat1 formed by a line aligned with the second inner surface and a line aligned with the first inner surface, which are provided at one boundary of the partition section, may be equal to a size of an angle γlat2 formed by a line aligned with the second inner surface and a line aligned with the first inner surface, which are provided at the other boundary of the partition section.

[0019] In a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, angles βlat1, βlat2 formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface may be greater than or equal to 10 degrees and less than or equal to 30 degrees.

[0020] The area of ​​each of the outer hole regions H2 may be 1.0 times or more the area of ​​the inner hole region H1.

[0021] In a cross section obtained by cutting a region of the airfoil body including the first inner surface, the second inner surface, and the third inner surface along a first direction, the connecting hole region H3 may include a section whose width increases as it approaches the external space.

[0022] In a cross section obtained by cutting a region of the airfoil body including the first inner surface, the second inner surface, and the third inner surface along a first direction, the outer hole region H2 may include a section whose width increases as it approaches the external space.

[0023] In a cross section obtained by cutting a region of the airfoil body including the first inner surface, the second inner surface, and the third inner surface along a first direction, the inner hole region H1 may include a section having a constant width.

[0024] In a cross section of the airfoil body, which is obtained by cutting a region including the first inner surface, the second inner surface, and the third inner surface along a second plane intersecting the first plane, the inner hole section H1, the outer hole section H2, or the connecting hole section H3 may include a section having a constant width.

[0025] In a cross section of the airfoil body obtained by cutting a region including the first inner surface, the second inner surface, and the third inner surface along a second plane intersecting the first plane, the first inner surface, the second inner surface, and the third inner surface may be located on the same plane.

[0026] According to another aspect of the present invention to achieve the above object, there is provided a gas turbine including: a compressor section that supplies compressed air; a combustor that receives the compressed air discharged from the compressor section and burns the compressed air to generate combustion gas; and a turbine section that receives the combustion gas generated in the combustor and includes a plurality of turbine airfoils, wherein the turbine airfoil includes an airfoil body including an outer wall that defines an interior space S, and the outer wall has cooling holes H that communicate the interior space S with an exterior space of the airfoil body, and inner surfaces of the outer wall that define the cooling holes H include a first inner surface that defines an inner hall region H1 of the cooling holes H that communicates with the interior space S, and a second inner surface that defines an outer hall region H2 of the cooling holes H that communicates with the exterior space, and a plurality of outer hall regions H2 are formed spaced apart from each other, and the outer wall includes a partition section provided between two adjacent outer hall regions H2. [Effects of the Invention]

[0027] The present invention provides a turbine airfoil that can achieve more effective film cooling than the prior art. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a cross-sectional view illustrating a schematic structure of a gas turbine according to the present invention; [Figure 2] 2 is a perspective view of a turbine blade provided in the turbine section of the gas turbine shown in FIG. 1. [Figure 3] 3 is a perspective view illustrating an example of the shape of a cooling hole formed in the turbine blade illustrated in FIG. 2. FIG. [Figure 4] 4 is a diagram illustrating the shape of the cooling hole illustrated in FIG. 3 cut along a first plane. [Figure 5] 3 is a perspective view illustrating another example of the shape of the cooling holes formed in the turbine blade illustrated in FIG. 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0029] A turbine airfoil and a gas turbine according to the present invention will now be described with reference to the drawings.

[0030] Turbine Airfoils and Gas Turbines FIG. 1 is a cross-sectional view illustrating a schematic structure of a gas turbine according to the present invention, and FIG. 2 is a perspective view of a turbine blade provided in a turbine section of the gas turbine illustrated in FIG.

[0031] A gas turbine generally includes a compressor section that supplies compressed air, a combustor that receives the compressed air discharged from the compressor section and burns the compressed air to generate combustion gas, and a turbine section that receives the combustion gas generated in the combustor and includes a plurality of turbine airfoils. Detailed structures of the compressor section, combustor, and turbine section will be described later with reference to the drawings.

[0032] 1, the gas turbine 100 may include a housing 102, and a diffuser 106 may be provided at the rear of the housing 102, through which combustion gases that have passed through the turbine are discharged. Also, a combustor 104 may be disposed in front of the diffuser 106, which receives a supply of compressed air and burns the compressed air.

[0033] In terms of the air flow direction, the compressor section 110 may be located upstream of the housing 102, and the turbine section 120 may be located downstream. In addition, a torque tube 130 may be located between the compressor section 110 and the turbine section 120 as a torque transmission member that transmits the rotational torque generated in the turbine section to the compressor section.

[0034] The compressor section 110 may be provided with a plurality of (e.g., 14) compressor rotor disks 140, each of which may be fastened together by tie bolts 150 so as not to be spaced apart in the axial direction.

[0035] Specifically, each compressor rotor disk 140 may be aligned with respect to the axial direction with the tie bolt 150 passing through approximately the center thereof. Here, adjacent compressor rotor disks 140 may be arranged such that their opposing surfaces are pressed together by the tie bolt 150 and are unable to rotate relative to each other.

[0036] A plurality of blades 144 may be radially coupled to the outer circumferential surface of the compressor rotor disk 140. Each blade 144 may be fastened to the compressor rotor disk 140 by having a root portion 146.

[0037] Vanes (not shown) fixed to the housing may be located between each rotor disk 140. Unlike the rotor disks, the vanes may be fixed so as not to rotate, and may serve to align the flow of compressed air that has passed through the blades of the compressor rotor disk and guide the air to the blades of the rotor disk located downstream.

[0038] The fastening method of the root portion 146 can be either a tangential type or an axial type. This can be selected depending on the required structure of a commercial gas turbine, and can have a commonly known dovetail or fir-tree type. Depending on the case, the blade can be fastened to the rotor disk using fastening devices other than the above types, such as fasteners such as keys or bolts.

[0039] The tie bolt 150 can be arranged to penetrate the center of multiple compressor rotor disks 140 and turbine rotor disks 180, and one end can be fastened into the compressor rotor disk located most upstream, and the other end can be fastened with a fixing nut 190.

[0040] The shape of the tie bolt 150 may have various structures depending on the gas turbine, and is not necessarily limited to the shape shown in Fig. 1. That is, as shown in the figure, it may have a shape in which one tie bolt penetrates the center of the rotor disk, or it may have a shape in which multiple tie bolts are arranged in a cylindrical shape, or a combination of these may be used.

[0041] Although not shown in the drawings, the compressor of the gas turbine may have a vane serving as a guide vane installed next to the diffuser to adjust the flow angle of the fluid entering the inlet of the combustor to the design flow angle after increasing the pressure of the fluid. The vane may be a deswirler.

[0042] The combustor 104 mixes the incoming compressed air with fuel and burns it to form high-energy, high-temperature, high-pressure combustion gases, and raises the combustion gas temperature to the heat limit that the combustor and turbine components can withstand through a constant-pressure combustion process.

[0043] A combustor, which constitutes the combustion system of a gas turbine, may be arranged in large numbers within a casing formed in a cell shape, and may be composed of a burner including a fuel injection nozzle, a combustor liner forming a combustion chamber, and a transition piece connecting the combustor and the turbine.

[0044] Specifically, the liner provides a combustion space where fuel injected from a fuel nozzle is mixed with compressed air from a compressor and burned. The liner may include a flame tube that provides the combustion space where fuel mixed with air is burned, and a flow sleeve that surrounds the flame tube to form an annular space. A fuel nozzle may be coupled to the front of the liner, and a spark plug may be coupled to the side wall.

[0045] On the other hand, a transition piece can be connected to the rear of the liner so that combustion gas burned by the spark plug can be sent to the turbine side. The outer wall of such a transition piece can be cooled by compressed air supplied from the compressor to prevent damage due to the high temperature of the combustion gas.

[0046] For this purpose, the transition piece may be provided with cooling holes so that air can be injected into the interior, and the compressed air can flow to the liner side after cooling the main body inside through the holes.

[0047] Cooling air that has cooled the transition piece flows through the annular space of the liner, and compressed air is provided to the cooling air outside the flow sleeve through cooling holes provided in the flow sleeve, allowing it to collide with the cooling air on the outer wall of the liner.

[0048] Meanwhile, high-temperature, high-pressure combustion gas discharged from the combustor can be supplied to the turbine section 120. As the supplied high-temperature, high-pressure combustion gas expands, it exerts impulse and reaction force on the turbine rotor, generating rotational torque. The rotational torque thus obtained is transmitted to the compressor section via the torque tube, and any power exceeding the power required to drive the compressor can be used to drive a generator, etc.

[0049] The turbine section 120 may basically have a similar structure to the compressor section. That is, the turbine section 120 also includes a plurality of turbine rotor disks 180 similar to the compressor rotor disks of the compressor section. Therefore, the turbine rotor disks 180 may also include a plurality of turbine airfoils 200 arranged radially. The turbine airfoils 200 may also be connected to the turbine rotor disk 180 by a method such as a dovetail. In addition, vanes (not shown) fixed to the housing may also be provided between the turbine airfoils 200 of the turbine rotor disk 180, and the vanes can guide the flow direction of the combustion gas that has passed through the blades.

[0050] 2, the turbine rotor disk 180 may have a substantially circular disk shape, and a plurality of coupling slots 180a may be formed on the outer periphery thereof. The coupling slots 180a may be formed to have a curved surface in the shape of a fir tree.

[0051] A turbine airfoil 200 may be fastened to the joining slot 180a. In FIG. 2, the turbine airfoil 200 may have a flat platform portion 200a approximately in the center. The platform portion 200a may serve to maintain a gap between the adjacent airfoils as the side surfaces of the platform portion 200a of an adjacent turbine airfoil contact each other. Root portions 200b may be formed on the bottom surface of the platform portion 200a. The root portions 200b may have a so-called axial-type shape, which is inserted into the joining slot 180a of the rotor disk 180 along the axial direction of the rotor disk 180.

[0052] The root portion 200b may have a bent portion in a generally fir-tree shape, which may be formed to correspond to the shape of the bent portion formed in the coupling slot. However, the coupling structure of the root portion does not necessarily have to have a fir-tree shape, and may be formed to have a dovetail shape.

[0053] An airfoil body 210 may be formed on an upper surface of the platform portion 200a. The airfoil body 210 may be formed to have an airfoil shape optimized according to the specifications of the gas turbine, and may have a leading edge disposed upstream and a trailing edge disposed downstream based on the flow direction of the combustion gas.

[0054] Unlike the blades in the compressor section, the airfoils in the turbine section are in direct contact with high-temperature, high-pressure combustion gases. Because the temperature of the combustion gases can reach as high as 1700°C, a cooling means is required. To this end, a cooling channel may be provided in the compressor section that adds compressed air and supplies it to the airfoils in the turbine section.

[0055] The cooling passages may extend outside the housing (external passages) or through the interior of the rotor disk (internal passages), and both external and internal passages may be used. In Figure 2, a number of cooling holes H may be formed on the surface of the airfoil body, and the cooling holes H may communicate with an internal space (not shown) formed inside the airfoil body 210 and serve to supply cooling air to the surface of the airfoil body 210.

[0056] Fig. 3 is a perspective view illustrating an example of the shape of the cooling hole formed in the turbine blade shown in Fig. 2, and Fig. 4 is a view illustrating the shape of the cooling hole shown in Fig. 3 cut along a first plane. Fig. 5 is a perspective view illustrating another example of the shape of the cooling hole formed in the turbine blade shown in Fig. 2.

[0057] 3 to 5, a turbine airfoil 200 according to the present invention may include an airfoil body 210 including an outer wall 220 that defines an interior space, and the outer wall 220 may have cooling holes H formed therein that communicate the interior space with an exterior space of the airfoil body 210.

[0058] The cooling holes H may be divided into a plurality of regions. More specifically, the cooling holes H may include an inner hole region H1 communicating with the internal space of the turbine airfoil 200 described above, an outer hole region H2 communicating with the external space, and a connecting hole region H3 connecting the inner hole region H1 and the outer hole region H2.

[0059] Meanwhile, the outer wall 220 may have an inner surface 222 that defines the cooling hole H. Here, according to the present invention, the inner surface 222 may include a first inner surface 222a that defines an inner hole region H1, a second inner surface 222b that defines an outer hole region H2, and a third inner surface 222c that defines a connecting hole region H3.

[0060] The first inner surface 222a and the third inner surface 222c may be distinguished based on a boundary where the first inner surface 222a and the third inner surface 222c are bent. More specifically, at the boundary between the first inner surface 222a and the third inner surface 222c, the third inner surface 222c may have a bent shape relative to the first inner surface 222a.

[0061] Meanwhile, according to the present invention, a plurality of outer hole regions H2 may be formed spaced apart from one another. Therefore, regions for partitioning the outer hole regions H2 spaced apart from one another may be formed in the outer wall 220. More specifically, the outer wall 220 may include a partition section 220-1 provided between two adjacent outer hole regions H2. Figures 3 and 4 illustrate two outer hole regions H2. However, Figure 5 illustrates three outer hole regions H2.

[0062] Meanwhile, when a plurality of outer hole regions H2 are provided, the second inner side 222b defining the outer hole region H2 may also be divided into a plurality of regions. That is, the second inner side 222b may be broadly divided into i) an inner side connected to the third inner side 222c, i.e., an outermost inner side among the plurality of second inner sides 222b (hereinafter, "outermost second inner side"), and ii) an inner side not connected to the third inner side 222c, i.e., an inner side located at the boundary of the partition section 220-1 (hereinafter, "partition section second inner side"). Herein, the boundary between the second inner side 222b and the third inner side 222c refers to the point where the second inner side 222b and the third inner side 222c are directly connected, and the second inner side at the boundary between the second inner side 222b and the third inner side 222c may refer to the outermost second inner side.

[0063] Meanwhile, as described above, the first inner side 222a and the third inner side 222c are distinguished based on the boundary where they are bent, whereas the second inner side 222b and the third inner side 222c may be distinguished based on the boundary where the plurality of outer hole regions H2 begin to branch off from the connection hole region H3. More specifically, the plurality of outer hole regions H2 may branch off from the connection hole region H3 at the boundary between the outer hole region H2 and the connection hole region H3, and the boundary between the second inner side 222b and the third inner side 222c may be formed at the section where the plurality of outer hole regions H2 branch off from the connection hole region H3.

[0064] Meanwhile, referring to Figures 3 and 4, in a cross section of a region of the airfoil body 210 of the turbine airfoil 200 according to the present invention, including the first inner surface 222a, the second inner surface 222b, and the third inner surface 222c, cut along a first plane, the direction in which the third inner surface 222c is bent relative to the first inner surface 222a at the boundary between the first inner surface 222a and the third inner surface 222c located on one side of the cooling hole H (e.g., the left side in Figure 4) and the direction in which the third inner surface 222c is bent relative to the first inner surface 222a at the boundary between the first inner surface 222a and the third inner surface 222c located on the other side of the cooling hole H (e.g., the right side in Figure 4) may be different from each other. Figure 4 shows that on the left side of the cooling hole H, the third inner surface 222c is bent counterclockwise relative to the first inner surface 222a, and on the right side of the cooling hole H, the third inner surface 222c is bent clockwise relative to the first inner surface 222a.

[0065] In addition, in a cross section of the airfoil body 210, which includes the first inner surface 222a, the second inner surface 222b, and the third inner surface 222c, cut along a first plane, a plurality of outer hole regions H2 may be spaced apart from each other along the extension direction of the first plane.

[0066] Next, referring to Figures 3 to 5, in a cross section of a region of the airfoil body 210 including the first inner surface 222a, the second inner surface 222b, and the third inner surface 222c, taken along a first plane, an angle formed by a line aligned with the first inner surface 222a and a line aligned with the third inner surface 222c at a boundary between the first inner surface 222a and the third inner surface 222c located on one side of the cooling hole H (e.g., the left side in Figure 4) is defined as βlatl, and an angle formed by a line aligned with the first inner surface 222a and a line aligned with the third inner surface 222c at a boundary between the first inner surface 222a and the third inner surface 222c located on the other side of the cooling hole H (e.g., the right side in Figure 4), is defined as βlat2. The size of βlatl and the size of βlat2 may be the same. Furthermore, in a cross section of the airfoil body 210 taken along a first plane through a region including the first inner surface 222a, the second inner surface 222b, and the third inner surface 222c, the second inner surface 222b (i.e., the outermost second inner surface) connected to the third inner surface 222c of the second inner surface 222b and the third inner surface 222c may be located on the same plane.

[0067] Also, as shown in FIG. 4, in a cross section of the airfoil body 210 taken along a first plane through a region including the first inner surface 222a, the second inner surface 222b, and the third inner surface 222c, if the angles formed by a line aligned with the first inner surface 222a and a line aligned with the second inner surface (222b, i.e., the second inner surface of the partition section) at the boundary of the partition section 220-1 that defines the outer hole region H2 are γlatl and γlat2, respectively, the angles βlatl and βlat2 formed by a line aligned with the first inner surface 222a and a line aligned with the third inner surface 222c at the boundary between the first inner surface 222a and the third inner surface 222c may be greater than or equal to γlatl and γlat2. Here, γlatl may be defined as the angle formed between a line aligned with the second inner surface 222b located at the boundary of one side of the partition section 220-1 (e.g., the left side in FIG. 4) and a line aligned with the first inner surface 222a, and γlat2 may be defined as the angle formed between a line aligned with the second inner surface 222b located at the boundary of the other side of the partition section 220-1 (e.g., the right side in FIG. 4) and a line aligned with the first inner surface 222a. More preferably, the sizes of βlatl and βlat2 may be larger than the sizes of γlatl and γlat2. Meanwhile, the sizes of γlatl and γlat2 may be equal to or greater than 0 degrees. Here, when the sizes of γlatl and γlat2 are 0 degrees, this may be understood as a case where the second inner surface 222b and the first inner surface 222a located at the boundary of the partition section 220-1 are formed in a straight line.

[0068] Meanwhile, in a cross section of the airfoil body 210, including the first inner surface 222a, the second inner surface 222b, and the third inner surface 222c, taken along the first plane, the size of γlatl may be equal to the size of γlat2. Furthermore, the angles βlatl and βlat2 formed by a line aligned with the first inner surface 222a and a line aligned with the third inner surface 222c at the boundary between the first inner surface 222a and the third inner surface 222c may be between 10 degrees and 30 degrees. For example, if the sizes of βlatl and βlat2 are less than 10 degrees or more than 30 degrees, the flow rate of the cooling fluid injected through each outer hole region H2 may be uneven or the workability of the cooling holes H may be reduced. Furthermore, to ensure smooth flow of the cooling fluid through the outer hole region H2, the area of ​​each of the outer hole regions H2 may be 1.0 times or more the area of ​​the inner hole region H1.

[0069] 3 to 5, the outer hole region H2 and the connecting hole region H3 may have a shape in which their widths increase toward the exterior space of the turbine airfoil. More specifically, in a cross section of the airfoil body 210, including the first inner side surface 222a, the second inner side surface 222b, and the third inner side surface 222c, taken along a first plane, the outer hole region H2 may include or consist of a section in which its width increases toward the exterior space, and the connecting hole region H3 may include or consist of a section in which its width increases toward the exterior space. Meanwhile, in a cross section of the airfoil body 210, including the first inner side surface 222a, the second inner side surface 222b, and the third inner side surface 222c, taken along a first plane, the inner hole region H1 may include or consist of a section with a constant width.

[0070] Meanwhile, the shape of the turbine airfoil according to the present invention, cut along a second plane intersecting the first plane, may have the following characteristics: For example, the second plane may be a plane that intersects the first plane perpendicularly.

[0071] More specifically, in a cross section obtained by cutting a region of the airfoil body 210 including the first inner side surface 222a, the second inner side surface 222b, and the third inner side surface 222c along a second plane intersecting with the first plane, the outer hole section H2 or the connecting hole section H3 may include a section with a constant width. More preferably, in a cross section obtained by cutting a region of the airfoil body 210 including the first inner side surface 222a, the second inner side surface 222b, and the third inner side surface 222c along a second plane intersecting with the first plane, the outer hole section H2 and the connecting hole section H3 may each consist of only a section with a constant width.

[0072] Furthermore, in a cross section of the airfoil body 210, taken along a second plane intersecting the first plane, the first inner surface 222a, the second inner surface 222b, and the third inner surface 222c, can be located on the same plane.

[0073] According to the present invention, a plurality of outer hole regions are formed to form a space for injecting cooling fluid to the exterior of a turbine airfoil, and partition sections are provided between adjacent outer hole regions, so that cooling fluid supplied from the connecting hole region to the outer hole region can adhere to the inner surface of the partition section before being injected to the exterior. Therefore, even if the outer hole region has a shape whose width increases toward the exterior space, flow separation of the cooling fluid does not occur, thereby maximizing the film cooling effect. Furthermore, according to the present invention, the cross-sectional area of ​​the region where the cooling fluid is injected is reduced compared to when a single hole is formed in the space occupied by the outer hole region and the partition section according to the present invention, so excessive decrease in momentum of the injected cooling fluid can be prevented, and the cooling air can be prevented from being rapidly diluted with combustion gas.

[0074] Although the present invention has been described above using limited examples and drawings, it goes without saying that the present invention is not limited thereto, and that various implementations are possible within the technical spirit of the present invention and the scope of the claims set forth below by a person having ordinary skill in the art to which the present invention pertains. (Other possible items) (Item 1) an airfoil body including an outer wall defining an interior space (S); The outer wall is formed with a cooling hole (H) that communicates the inner space (S) with an outer space of the airfoil body, The inner surface of the outer wall defining the cooling hole (H) is a first inner surface defining an inner hole region (H1) of the cooling hole (H) that communicates with the internal space (S); a second inner surface defining an outer hole region (H2) of the cooling hole (H) communicating with the external space, The outer hole region (H2) is formed in a plurality of regions spaced apart from each other, The outer wall is a partition section provided between two adjacent outer hole regions (H2). (Item 2) The inner surface is The cooling hole (H) further includes a third inner side defining a connecting hole region (H3) connecting the inner hole region (H1) and the outer hole region (H2), Item 2. The turbine airfoil of item 1, wherein at a boundary between the outer hole region (H2) and the connecting hole region (H3), the outer hole regions (H2) diverge from the connecting hole region (H3). (Item 3) a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 3. The turbine airfoil according to item 2, wherein a direction in which the third inner surface is bent relative to the first inner surface at a boundary between the first inner surface and the third inner surface located on one side of the cooling hole (H) is different from a direction in which the third inner surface is bent relative to the first inner surface at a boundary between the first inner surface and the third inner surface located on the other side of the cooling hole (H). (Item 4) a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 3. The turbine airfoil according to claim 2, wherein the plurality of outer hole regions (H2) are spaced apart from one another along an extension direction of the first plane. (Item 5) a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 3. The turbine airfoil according to item 2, wherein a size of an angle (βlat1) formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface located on one side of the cooling hole (H) is equal to a size of an angle (βlat2) formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface located on the other side of the cooling hole (H). (Item 6) a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, Item 3. The turbine airfoil of item 2, wherein the second inner surface and the third inner surface are coplanar. (Item 7) a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 7. The turbine airfoil according to item 6, wherein at a boundary between the first inner surface and the third inner surface, a size of an angle (βlat1, βlat2) formed by a line aligned with the first inner surface and a line aligned with the third inner surface is greater than or equal to an angle (γlat1, γlat2) formed by a line aligned with the second inner surface and a line aligned with the first inner surface, the angle being provided at a boundary of the partition section. (Item 8) a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 7. The turbine airfoil according to item 6, wherein a size of an angle (γlat1) formed by a line aligned with the second inner surface and a line aligned with the first inner surface provided at one boundary of the compartment section is equal to a size of an angle (γlat2) formed by a line aligned with the second inner surface and a line aligned with the first inner surface provided at the other boundary of the compartment section. (Item 9) a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, Item 7. The turbine airfoil according to item 6, wherein a size of an angle (βlat1, βlat2) formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface is greater than or equal to 10 degrees and less than or equal to 30 degrees. (Item 10) Item 2. The turbine airfoil of item 1, wherein an area of ​​each of the plurality of outer hole regions (H3) is equal to or greater than 1.0 times an area of ​​the inner hole region (H1). (Item 11) a cross section of the airfoil body taken along a first direction through a region including the first inner surface, the second inner surface, and the third inner surface, The connecting hole region (H3) is Item 3. The turbine airfoil of item 2, including a section that increases in width adjacent the exterior space. (Item 12) a cross section of the airfoil body taken along a first direction through a region including the first inner surface, the second inner surface, and the third inner surface, The outer hole region (H2) is Item 3. The turbine airfoil of item 2, including a section that increases in width adjacent the exterior space. (Item 13) a cross section of the airfoil body taken along a first direction through a region including the first inner surface, the second inner surface, and the third inner surface, The inner hole region (H1) is Item 3. The turbine airfoil of item 2, including a section of constant width. (Item 14) a cross section of the airfoil body, the cross section being obtained by cutting a region of the airfoil body including the first inner surface, the second inner surface, and the third inner surface along a second plane intersecting the first plane, The inner hole section (H1), the outer hole section (H2) or the connecting hole section (H3) Item 4. The turbine airfoil of item 3, including a section of constant width. (Item 15) a cross section of the airfoil body, the cross section being obtained by cutting a region of the airfoil body including the first inner surface, the second inner surface, and the third inner surface along a second plane intersecting the first plane, Item 3. The turbine airfoil of item 2, wherein the first inner surface, the second inner surface, and the third inner surface are coplanar. (Item 16) a compressor section for supplying compressed air; a combustor into which the compressed air discharged from the compressor section flows and which combusts the compressed air to generate combustion gas; a turbine section into which combustion gases generated in the combustor flow and which includes a plurality of turbine airfoils; The turbine airfoil comprises: an airfoil body including an outer wall defining an interior space (S); The outer wall is formed with a cooling hole (H) that communicates the inner space (S) with an outer space of the airfoil body, The inner surface of the outer wall defining the cooling hole (H) is a first inner surface defining an inner hole region (H1) of the cooling hole (H) that communicates with the internal space (S); a second inner surface defining an outer hole region (H2) of the cooling hole (H) communicating with the external space, The outer hole region (H2) is formed in a plurality of regions spaced apart from each other, The outer wall is A gas turbine including a compartment section provided between two adjacent outer hall regions (H2). [Explanation of symbols]

[0075] 100 Gas Turbine 200 Turbine Airfoil 210 Airfoil body 220 Exterior Wall 220-1 Section 222 Inner surface 222a 1st inner surface 222b Second inner surface 222c 3rd inner surface H Cooling hole H1 inner hole region H2 outer hole region H3 Connected Hole Region

Claims

1. an airfoil body including an outer wall defining an interior space; a cooling hole is formed in the outer wall, the cooling hole communicating the inner space with an outer space of the airfoil body; The inner surface defining the cooling hole at the outer wall is a first inner surface defining an inner hole region of the cooling hole that communicates with the internal space; a second inner surface defining an outer hole region of the cooling hole that communicates with the external space; The outer hole region is formed in a plurality of regions spaced apart from each other, The outer wall is a compartment section provided between two adjacent outer hole regions.

2. The inner surface is a third inner surface defining a connecting hole region connecting the inner hole region and the outer hole region of the cooling hole; The turbine airfoil of claim 1 , wherein a plurality of said outer hole regions diverge from said connecting hole region at a boundary between said outer hole region and said connecting hole region.

3. a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 3. The turbine airfoil of claim 2, wherein a direction in which the third inner surface is bent relative to the first inner surface at a boundary between the first inner surface and the third inner surface located on one side of the cooling hole is different from a direction in which the third inner surface is bent relative to the first inner surface at a boundary between the first inner surface and the third inner surface located on the other side of the cooling hole.

4. a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, The turbine airfoil of claim 2 , wherein a plurality of the outer hole regions are spaced apart from one another along an extension direction of the first plane.

5. a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 3. The turbine airfoil of claim 2, wherein a size of an angle formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface located on one side of the cooling hole is the same as a size of an angle formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface located on the other side of the cooling hole.

6. a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, The turbine airfoil of claim 2 , wherein the second inner surface and the third inner surface are coplanar.

7. a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 7. The turbine airfoil of claim 6, wherein a size of an angle formed by a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface is greater than or equal to an angle formed by a line aligned with the second inner surface and a line aligned with the first inner surface at a boundary of the partition section.

8. a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 7. The turbine airfoil of claim 6, wherein a size of an angle formed by a line aligned with the second inner surface and a line aligned with the first inner surface at one boundary of the partition section is equal to a size of an angle formed by a line aligned with the second inner surface and a line aligned with the first inner surface at another boundary of the partition section.

9. a cross section of the airfoil body taken along a first plane through a region including the first inner surface, the second inner surface, and the third inner surface, 7. The turbine airfoil of claim 6, wherein an angle between a line aligned with the first inner surface and a line aligned with the third inner surface at a boundary between the first inner surface and the third inner surface is greater than or equal to 10 degrees and less than or equal to 30 degrees.

10. The turbine airfoil of claim 1 , wherein an area of ​​each of said plurality of outer hole regions is greater than or equal to 1.0 times an area of ​​said inner hole region.

11. a cross section of the airfoil body taken along a first direction through a region including the first inner surface, the second inner surface, and the third inner surface, The connecting hole region is A turbine airfoil according to claim 2 including a section of increasing width adjacent the exterior space.

12. a cross section of the airfoil body taken along a first direction through a region including the first inner surface, the second inner surface, and the third inner surface, The outer hole region is A turbine airfoil according to claim 2 including a section of increasing width adjacent the exterior space.

13. a cross section of the airfoil body taken along a first direction through a region including the first inner surface, the second inner surface, and the third inner surface, The inner hole region is A turbine airfoil according to any one of claims 2 to 9, including a section of constant width.

14. a cross section of the airfoil body, the cross section being obtained by cutting a region of the airfoil body including the first inner surface, the second inner surface, and the third inner surface along a second plane intersecting the first plane, The inner hole region, the outer hole region, or the connecting hole region is The turbine airfoil of claim 3 including a constant width section.

15. a cross section of the airfoil body, the cross section being obtained by cutting a region of the airfoil body including the first inner surface, the second inner surface, and the third inner surface along a second plane intersecting the first plane, The turbine airfoil of claim 3 , wherein the first inner surface, the second inner surface, and the third inner surface are coplanar.

16. a compressor section for supplying compressed air; a combustor into which the compressed air discharged from the compressor section flows and which combusts the compressed air to generate combustion gas; a turbine section into which combustion gases generated in the combustor flow and which includes a plurality of turbine airfoils; The turbine airfoil comprises: an airfoil body including an outer wall defining an interior space; a cooling hole is formed in the outer wall, the cooling hole communicating the inner space with an outer space of the airfoil body; The inner surface defining the cooling hole at the outer wall is a first inner surface defining an inner hole region of the cooling hole that communicates with the internal space; a second inner surface defining an outer hole region of the cooling hole that communicates with the external space; The outer hole region is formed in a plurality of regions spaced apart from each other, The outer wall is A gas turbine including a compartment section provided between two adjacent outer hall regions.

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