Air foil and gas turbine comprising the same

Abstract

To disclose an air foil with improved cooling efficiency, and a gas turbine comprising the air foil.SOLUTION: An airfoil comprises: an intake surface and a pressure surface in which a cooling hole is formed; at least one main cavity formed in an internal space formed by the intake surface and the pressure surface, and into which cooling fluid flows; an internal cooling flow path formed inside a wall body forming the intake surface and the pressure surface; a plurality of impingement jet holes that is formed on the inside surfaces of the intake surface and the pressure surface, and forces the cooling fluid into the internal cooling flow path for impingement cooling; and a sub-cavity formed so as to surround an internal cooling flow path outlet formed at an end part of the internal cooling flow path, and configured such that the internal cooling flow path outlet and an inlet of the cooling hole are in communication with each other.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an airfoil and a gas turbine including the same.

Background Art

[0002] A turbine is a mechanical device that obtains rotational force by impulse force or reaction force using the flow of a compressible fluid such as steam or gas, and includes a steam turbine using steam and a gas turbine using high-temperature combustion gas.

[0003] Among these, a gas turbine is mainly composed of a compressor, a combustor, and a turbine. The compressor is provided with an air inlet for introducing air, and a plurality of compressor vanes and compressor blades are alternately arranged in a compressor casing.

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

[0005] The turbine has a plurality of turbine vanes and turbine blades alternately arranged in a turbine casing. Further, a rotor is arranged so as to penetrate the central portions of the compressor, the combustor, the turbine, and the exhaust chamber.

[0006] Both ends of the rotor are rotatably supported by bearings. A plurality of disks are fixed to the rotor, and respective blades are connected thereto. At the same time, a drive shaft such as a generator is connected to the end on the exhaust chamber side.

[0007] Such a gas turbine does not have a reciprocating mechanism like a piston of a four-stroke engine, so there is no mutual friction part like a piston-cylinder, the consumption of lubricating oil is extremely small, the amplitude which is a characteristic of a reciprocating machine is significantly reduced, and it has the merit of enabling high-speed movement.

[0008] Briefly explaining the operation of a gas turbine, high-temperature combustion gas is produced by mixing and burning the air compressed by a compressor with fuel, and the combustion gas thus produced is injected toward the turbine side. The injected combustion gas generates a rotational force while passing through the turbine vanes and turbine blades, thereby rotating the rotor.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] An object of the present invention is to provide an airfoil with improved cooling efficiency and a gas turbine including the same.

Means for Solving the Problems

[0011] An airfoil according to an embodiment of the present invention includes a suction surface and a pressure surface on which cooling holes are formed, at least one main cavity formed in an internal space formed by the suction surface and the pressure surface and into which a cooling fluid flows, an internal cooling flow path formed inside a wall body forming the suction surface and the pressure surface, a plurality of impingement jet holes formed on inner surfaces of the suction surface and the pressure surface to allow the cooling fluid to flow into the internal cooling flow path for impingement cooling, and a sub-cavity formed to surround an internal cooling flow path outlet formed at an end of the internal cooling flow path and communicating the internal cooling flow path outlet with an inlet of the cooling hole.

[0012] In the airfoil according to an embodiment of the present invention, a plurality of impingement jet holes may be formed along the span direction on inner surfaces of the suction surface and the pressure surface.

[0013] In the airfoil according to an embodiment of the present invention, the impingement jet holes may be formed on the trailing edge side, and the internal cooling flow path outlet may be formed on the leading edge side.

[0014] In the airfoil according to an embodiment of the present invention, a plurality of sub-cavities may be formed along the span direction on the inner surfaces of the suction surface and the pressure surface.

[0015] In the airfoil according to an embodiment of the present invention, it may include a first cooling fin that protrudes from one surface to the other surface direction inside the wall forming the internal cooling flow path and is formed separated from the other surface.

[0016] In the airfoil according to an embodiment of the present invention, the first cooling fin may be formed between any one impingement jet hole and its adjacent impingement jet hole.

[0017] In the airfoil according to an embodiment of the present invention, it may include a cooling protrusion that protrudes from the other surface to one surface direction inside the wall forming the internal cooling flow path and is formed below the impingement jet hole.

[0018] In the airfoil according to an embodiment of the present invention, it may include a second cooling fin formed by connecting one surface and the other surface inside the wall forming the internal cooling flow path.

[0019] In the airfoil according to an embodiment of the present invention, the second cooling fin may be formed between any one impingement jet hole and its adjacent impingement jet hole.

[0020] In the airfoil according to an embodiment of the present invention, it may further include an impingement cavity configured to cause the cooling fluid discharged through the internal cooling flow path outlet to impinge on the wall surface of the suction surface or the pressure surface before being discharged to the outside through the cooling holes.

[0021] A gas turbine according to an embodiment of the present invention includes a compressor that compresses incoming air, a combustor that mixes and burns the compressed air from the compressor and fuel, a turbine that generates power with the combustion gas from the combustor and includes turbine vanes that guide the combustion gas on a combustion gas path through which the combustion gas passes, and turbine blades that rotate by the combustion gas on the combustion gas path. Here, at least one of the turbine vanes or the turbine blades includes an airfoil. Here, the airfoil includes a suction surface and a pressure surface on which cooling holes are formed, at least one main cavity formed in an internal space formed by the suction surface and the pressure surface and into which a cooling fluid flows, an internal cooling flow path formed inside a wall body forming the suction surface and the pressure surface, a plurality of impingement jet holes formed on inner surfaces of the suction surface and the pressure surface and configured to allow the cooling fluid to flow into the internal cooling flow path for impingement cooling, and a sub-cavity formed so as to surround an internal cooling flow path outlet formed at an end of the internal cooling flow path and configured to communicate the internal cooling flow path outlet and an inlet of the cooling hole.

[0022] In the gas turbine according to an embodiment of the present invention, a plurality of impingement jet holes may be formed along the span direction on inner surfaces of the suction surface and the pressure surface.

[0023] In the gas turbine according to an embodiment of the present invention, the impingement jet holes may be formed on the trailing edge side, and the internal cooling flow path outlet may be formed on the leading edge side.

[0024] In the gas turbine according to an embodiment of the present invention, a plurality of sub-cavities may be formed along the span direction on inner surfaces of the suction surface and the pressure surface.

[0025] In the gas turbine according to an embodiment of the present invention, it may include first cooling fins that protrude from one surface to the other surface direction inside a wall body forming the internal cooling flow path and are formed separated from the other surface.

[0026] In the gas turbine according to an embodiment of the present invention, the first cooling fin may be formed between any one collision jet hole and an adjacent collision jet hole.

[0027] In the gas turbine according to an embodiment of the present invention, it may include a cooling protrusion that protrudes in one surface direction from the other surface inside the wall body forming the internal cooling flow path and is formed below the collision jet hole.

[0028] In the gas turbine according to an embodiment of the present invention, it may include a second cooling fin formed by connecting one surface and the other surface inside the wall body forming the internal cooling flow path.

[0029] In the gas turbine according to an embodiment of the present invention, the second cooling fin may be formed between any one collision jet hole and an adjacent collision jet hole.

[0030] In the gas turbine according to an embodiment of the present invention, it may further include a collision cavity that causes the cooling fluid discharged through the internal cooling flow path outlet to collide with the surface of the wall body forming the suction surface or the pressure surface before being discharged to the outside through the cooling hole.

[0031] In addition, specific matters of embodiments according to various aspects of the present invention are included in the following detailed description.

Advantages of the Invention

[0032] According to an embodiment of the present invention, the cooling efficiency can be improved by i) cooling by the collision of the cooling fluid with the internal cooling flow path, ii) increasing the cooling time by the internal flow of the internal cooling flow path, iii) increasing the air curtain effect by the discharge through the cooling hole close to the leading edge (LE) side, etc.

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0034] The present invention can have various examples with various conversions added, but specific examples will be illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that all conversions, equivalents, or alternatives included in the spirit and technical scope of the present invention are included.

[0035] The terms used in the present invention are merely used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present invention, terms such as "including" or "having" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and it should be understood that the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof is not precluded in advance.

[0036] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. At this time, in the accompanying drawings, it should be noted that the same components are represented by the same reference numerals as much as possible. Also, detailed descriptions of known functions and configurations that may obscure the gist of the present invention are omitted. For the same reason, in the accompanying drawings, some components are exaggerated, omitted, or shown schematically.

[0037] FIG. 1 is a perspective view showing a gas turbine according to an embodiment of the present invention with a partial cutaway, and FIG. 2 is a cross-sectional view showing a schematic structure of the gas turbine according to an embodiment of the present invention.

[0038] As shown in FIG. 1, the gas turbine 1000 according to the first embodiment of the present invention includes a compressor 1100, a combustor 1200, and a turbine 1300. The compressor 1100 includes a plurality of compressor blades 1110 provided radially. The compressor 1100 rotates the compressor blades 1110, and air moves while being compressed by the rotation of the compressor blades 1110. The size and mounting angle of the compressor blades 1110 may vary depending on the mounting position. In the first embodiment, the compressor 1100 is directly or indirectly connected to the turbine 1300 and can receive a part of the power generated by the turbine 1300 and use it for the rotation of the compressor blades 1110.

[0039] The air compressed by the compressor 1100 moves to the combustor 1200. The combustor 1200 includes a plurality of combustion chambers 1210 arranged annularly and a fuel nozzle module 1220.

[0040] As shown in FIG. 2, the gas turbine 1000 according to the first embodiment of the present invention includes a housing 1010, and a diffuser 1400 through which the combustion gas that has passed through the turbine is discharged is provided on the rear side of the housing 1010. And a combustor 1200 that receives and combusts the compressed air is arranged on the front side of the diffuser 1400.

[0041] Explaining with reference to the air flow direction, the compressor 1100 is located on the upstream side of the housing 1010, and the turbine 1300 is arranged on the downstream side. And between the compressor 1100 and the turbine 1300, a torque tube 1500 as a torque transmission member that transmits the rotational torque generated from the turbine 1300 to the compressor 1100 is arranged.

[0042] The compressor 1100 is provided with a plurality (for example, 14) of compressor rotor disks 1120, and each of the compressor rotor disks 1120 is fastened by tie rods 1600 so as not to be axially separated.

[0043] Specifically, each of the compressor rotor disks 1120 is aligned along the axial direction with the tie rod 1600 constituting the rotating shaft passing through the substantially center. Here, the opposing surfaces of the adjacent compressor rotor disks 1120 are pressed by the tie rod 1600 and arranged so as not to be relatively rotatable.

[0044] A plurality of compressor blades 1110 are radially coupled to the outer peripheral surface of the compressor rotor disk 1120. Each of the compressor blades 1110 is fastened to the compressor rotor disk 1120.

[0045] Between each rotor disk 1120, there is a compressor vane (not shown) fixedly disposed in the housing. The compressor vane is fixed so as not to rotate differently from the rotor disk, and aligns the flow of compressed air passing through the compressor blade 1110 of the compressor rotor disk 1120, and guides the air to the compressor blade 1110 of the rotor disk 1120 located on the downstream side.

[0046] The tie rod 1600 is disposed to penetrate the central portions of the plurality of compressor rotor disks 1120 and the turbine rotor disks 1320, and the tie rod 1600 may be composed of one or a plurality of tie rods. One end portion of the tie rod 1600 is fastened within the compressor rotor disk located on the most upstream side, and the other end portion of the tie rod 1600 is fastened by the fixing nut 1450.

[0047] Since the form of the tie rod 1600 may have various structures depending on the gas turbine, it is not necessarily limited to the form presented in FIG. 2. That is, as shown in the figure, it may have a form in which one tie rod penetrates the central portion of the rotor disk, a form in which a plurality of tie rods are arranged in a circumferential shape, or a mixture of these is also possible.

[0048] Although not shown, the compressor of the gas turbine may be provided with a vane that serves as a guide vane at the next position after the diffuser in order to increase the pressure of the fluid and adjust the flow angle of the fluid entering the inlet of the combustor to the designed flow angle, and this is called a deswirler.

[0049] In the combustor 1200, the inflowing compressed air is mixed with fuel and burned to produce high-energy high-temperature and high-pressure combustion gas, and the temperature of the combustion gas is increased to the heat-resistant limit that the combustor and turbine components can withstand in the isobaric combustion process.

[0050] The combustors that make up the combustion system of a gas turbine may be arranged in a plurality within a housing formed in a cell form, and include a burner that includes a fuel injection nozzle and the like, a combustor liner that forms a combustion chamber, and a transition piece that serves as a connection between the combustor and the turbine.

[0051] Specifically, the liner provides a combustion space where the fuel injected by the fuel nozzle is mixed with the compressed air of the compressor and burned. Such a liner can include a flame tube that provides a combustion space where the fuel mixed with air is burned, and a flow sleeve that forms an annular space while surrounding the flame tube. Further, a fuel nozzle is coupled to the front end of the liner, and an ignition plug is coupled to the side wall.

[0052] On the other hand, a transition piece is coupled to the rear end of the liner so that the combustion gas burned by the ignition plug can be sent to the turbine side. Such a transition piece has its outer wall cooled by the compressed air supplied from the compressor so as to prevent damage due to the high temperature of the combustion gas.

[0053] For this purpose, the transition piece is provided with holes for cooling so that air can be injected therein, and the compressed air cools the body inside through the holes and then flows to the liner side.

[0054] The cooling air that cools the aforementioned transition piece flows in the annular space of the liner, and compressed air can be provided as cooling air from the outside of the flow sleeve through cooling holes provided in the flow sleeve and collide with the outer wall of the liner.

[0055] On one hand, the high-temperature and high-pressure combustion gas discharged from the combustor is supplied to the turbine 1300. The supplied high-temperature and high-pressure combustion gas collides with the rotating blades of the turbine while expanding, providing a reaction force to generate rotational torque. The rotational torque thus obtained is transmitted to the compressor via the torque tube 1500, and the power exceeding the power required to drive the compressor is used to drive a generator or the like.

[0056] The turbine 1300 is basically similar in structure to the compressor. That is, the turbine 1300 is also provided with a plurality of turbine rotor disks 1320 similar to the compressor rotor disk of the compressor. Therefore, the turbine rotor disk 1320 also includes a plurality of turbine blades 1310 arranged radially. The turbine blade 1310 can be coupled to the turbine rotor disk 1320 by a method such as a dovetail. At the same time, between the turbine blades 131, there are provided turbine vanes 1330 fixed to the turbine casing 1350 to guide the flow direction of the combustion gas passing through the turbine blades 1310.

[0057] The airfoil according to an embodiment of the present invention may be an airfoil applied to at least any one of the compressor blade 1110, the compressor vane, the turbine blade 1310, and the turbine vane 1330. In the following description, the airfoil applied to the turbine blade 1310 of the gas turbine will be described as an example. Also, the technical idea described in this specification is not limited to gas turbines, and is applicable to devices provided with airfoils such as steam turbines.

[0058] FIG. 3 is a perspective view of a turbine blade including an airfoil according to an embodiment of the present invention, and FIG. 4 is a plan view seen from above by cutting the A-A' portion of FIG. 3.

[0059] The turbine blade 1310 according to an embodiment of the present invention includes a root portion 1312 and an airfoil 2000.

[0060] Referring to FIG. 3, the turbine blade 1310 is attached to the turbine rotor disk 1320 to cause the turbine to rotate by high-pressure combustion gas. A root portion 1312 coupled to the turbine rotor disk 1320 is formed on the lower side, and an airfoil 2000 that rotates by the pressure of air is integrally coupled to the upper side of the root portion 1312, so that the turbine rotates by the pressure difference between the front and rear surfaces of the airfoil 2000.

[0061] On the outer surface of the root portion 1312, a shank and a platform protruding outward are formed to ensure firm fixation. An inlet 1312a for the cooling fluid to flow into the airfoil 2000 is formed in the root portion 1312. The cooling fluid is a part of the compressed air compressed by the compressor 1100, and is supplied from the compressor 1100 to the root portion 1312 of the turbine blade 1310. While flowing into the airfoil 2000 through the inlet 1312a, the turbine blade 1310 is cooled. Alternatively, the cooling fluid is supplied to the root portion 1312 through an internal flow path (not shown) connecting the compressor 1100 to the turbine 1300, and while flowing into the airfoil 2000 through the inlet 1312a, the turbine blade 1310 is cooled.

[0062] The airfoil 2000 is disposed above the root portion 1312. On the other hand, when the airfoil 2000 is formed on the turbine vane 1330, the airfoil 2000 is formed between the outer shroud and the inner shroud, and the cooling fluid flows in through a cooling fluid flow path formed on the outer shroud side or a cooling fluid flow path formed on the inner shroud side.

[0063] The airfoil 2000 is formed such that a suction side 2001 protruding with a curved surface bulging outward is formed on the front surface where the combustion gas flows in, and a pressure side 2002 forming a curved surface recessed and sunken toward the suction side 2001 is formed on the rear surface, so that a smooth air flow is performed while maximizing the pressure difference between the front and rear of the airfoil 2000.

[0064] The airfoil 2000 includes a leading edge (LE) and a trailing edge (TE) which are the contacting ends of the pressure surface 2002 and the suction surface 2001. The leading edge LE means the end of the front portion that faces the fluid flowing through the airfoil 2000, and the trailing edge TE means the end of the rear portion of the airfoil 2000. Also, the direction from the root portion towards the tip of the airfoil is referred to as the span direction.

[0065] The airfoil 2000 includes a plurality of cooling holes 2003 formed through the suction surface 2001 or the pressure surface 2002. While the cooling fluid is injected through the cooling holes 2003, it can act like an air curtain on the outer surface of the airfoil and cool the outer surface of the airfoil 2000 in a so-called film cooling method.

[0066] Referring to FIG. 4, the airfoil 2000 according to an embodiment of the present invention includes a main cavity 2100, a cooling channel portion 2200, and a sub-cavity 2300.

[0067] At least one or more main cavities 2100 may be formed in the internal space formed by the suction surface 2001 and the pressure surface 2002 of the airfoil 2000. The main cavity 2100 may be formed along the span direction. When a plurality of main cavities 2100 are formed, the main cavities 2100 may be formed by being divided into a plurality along the longitudinal direction extending from the leading edge LE to the trailing edge TE direction. Although the drawing exemplifies that two main cavities are formed, it is not limited thereto.

[0068] The cooling fluid flowing through the main cavity 2100 flows into and through the cooling channel portion 2200 while cooling the suction surface 2001 and the pressure surface 2002. The cooling channel portion 2200 is formed inside the wall body forming the suction surface 2001 and the pressure surface 2002. The cooling channel portion 2200 can be realized in various forms, which will be described later with reference to FIGS. 5 to 10.

[0069] The sub-cavity 2300 is formed to protrude by a predetermined size from the inner surfaces of the suction surface 2001 and the pressure surface 2002. Similar to the main cavity 2100, a plurality of sub-cavities 2300 are formed along the span direction on the inner surfaces of the suction surface 2001 and the pressure surface 2002. The sub-cavity 2300 is formed so as to surround the cooling channel outlet (2230, see FIG. 5) and the inlet (2003a, see FIG. 5) of the cooling hole, so that the cooling channel outlet 2230 and the inlet 2003a of the cooling hole are fluidly isolated from the main cavity 2100.

[0070] FIG. 5 is a plan view showing an enlarged view of a portion B in FIG. 4, showing a part of the airfoil according to the first embodiment of the present invention, and FIG. 6 is a diagram for explaining the cooling effect due to the flow of the cooling fluid in the airfoil according to the first embodiment of the present invention.

[0071] Referring to FIG. 5, the cooling channel portion 2200 includes the impinging jet holes 2210, the internal cooling channels 2220, and the cooling channel outlet 2230.

[0072] A plurality of impinging jet holes 2210 may be formed along the span direction on the inner surfaces of the suction surface 2001 and the pressure surface 2002. The cooling fluid flowing in through the inlet 1312a of the root portion 1312 can flow into the impinging jet holes 2210 while flowing in the span direction along the main cavity 2100.

[0073] The internal cooling flow path 2220 is formed inside the wall body that forms the suction surface 2001 and the pressure surface 2002. The internal cooling flow path 2220 may be formed to extend in the longitudinal direction of the wall body (the direction connecting the leading edge and the trailing edge) inside the wall body.

[0074] A cooling flow path outlet 2230 is formed at the end of the internal cooling flow path 2220. The cooling flow path outlet 2230 may be formed on the same surface as the impinging jet holes 2210. That is, the cooling flow path outlet 2230 may be formed on the inner surface of the suction surface 2001 and the pressure surface 2002.

[0075] Referring to FIG. 6, the cooling fluid flowing into the impinging jet holes 2210 collides with one surface of the internal cooling flow path 2220 (impinging jet) to primarily cool the suction surface 2001 or the pressure surface 2002, and then, while flowing along the internal cooling flow path 2220, performs secondary cooling and is then discharged through the cooling flow path outlet 2230.

[0076] At this time, the impinging jet holes 2210 are formed on the trailing edge TE side, and the cooling flow path outlet 2230 is formed on the leading edge LE side, so that the flow direction of the cooling fluid flowing through the internal cooling flow path 2220 is opposite to the flow direction of the high-temperature combustion gas HG. When configured in this way, since the cooling fluid is discharged to the outside of the airfoil 2000 through the cooling holes 2003 close to the leading edge LE side, the air curtain effect can be further enhanced.

[0077] According to the airfoil according to the first embodiment of the present invention as described above, the cooling efficiency can be improved by i) cooling by the collision of the cooling fluid with the internal cooling flow path 2220, ii) increasing the cooling time by the internal flow of the internal cooling flow path 2220, iii) increasing the air curtain effect by the discharge through the cooling holes 2003 close to the leading edge LE side, and the like.

[0078] FIG. 7 is a plan view showing an enlarged view of part B of FIG. 4, and shows a part of an airfoil according to the second embodiment of the present invention.

[0079] Referring to FIG. 7, the cooling channel portion 2200 of the present embodiment includes a collision jet hole 2210, an internal cooling channel 2220, a cooling channel outlet 2230, and a first cooling fin 2240. Since the collision jet hole 2210, the internal cooling channel 2220, and the cooling channel outlet 2230 are substantially the same as those in the above-described first embodiment, repeated description is omitted.

[0080] The first cooling fin 2240 is formed to protrude in a predetermined size from one surface to the other surface inside the wall forming the internal cooling channel 2220 and is formed separated from the other surface. FIG. 7 illustrates an example in which the first cooling fin 2240 protrudes from the upper surface (inner surface) to the lower surface (outer surface) inside the wall forming the internal cooling channel 2220. Further, the first cooling fin 2240 is formed between any one collision jet hole 2210 and its adjacent collision jet hole 2210.

[0081] A part of the cooling fluid flowing through the internal cooling channel 2220 collides with the first cooling fin 2240 to form a vortex, and the rest of the cooling fluid goes straight toward the cooling channel outlet 2230. That is, the first cooling fin 2240 can improve the cooling efficiency by imparting vortex and straightness to the cooling fluid.

[0082] According to the airfoil according to the second embodiment of the present invention as described above, the cooling efficiency can be improved by i) cooling by collision of the cooling fluid with the internal cooling channel 2220, ii) improvement of the cooling efficiency by the first cooling fin 2240, iii) increase of the air curtain effect by discharge through the cooling hole 2003 close to the leading edge LE side, and the like.

[0083] FIG. 8 is a plan view showing an enlarged view of a portion B in FIG. 4, and shows a part of an airfoil according to a third embodiment of the present invention.

[0084] Referring to FIG. 8, the cooling channel portion 2200 of the present embodiment includes a collision jet hole 2210, an internal cooling channel 2220, a cooling channel outlet 2230, and a cooling protrusion 2250. Since the collision jet hole 2210, the internal cooling channel 2220, and the cooling channel outlet 2230 are substantially the same as those in the first embodiment described above, repeated description will be omitted.

[0085] The cooling protrusion 2250 is formed below the collision jet hole 2210. The cooling protrusion 2250 protrudes in a predetermined size from the other surface (lower surface) to one surface (upper surface) direction inside the wall forming the internal cooling channel 2220.

[0086] The cooling fluid flowing vertically through the collision jet hole 2210 collides with the cooling protrusion 2250 (collision jet), spreads in the radial direction, and primary cools the suction surface 2001 or the pressure surface 2002, and then performs secondary cooling while flowing along the internal cooling channel 2220, and is then discharged through the cooling channel outlet 2230.

[0087] At this time, the distance between the collision jet hole 2210 and the internal cooling channel 2220 is shortened by the size of the cooling protrusion 2250, so that the collision distance is shortened and the collision cooling efficiency can be improved. In addition, the area in contact with the cooling fluid is widened by the size of the cooling protrusion 2250, and the collision cooling efficiency can be improved.

[0088] According to the airfoil according to the third embodiment of the present invention as described above, i) the cooling efficiency is improved by shortening the collision distance by the cooling protrusion 2250, ii) the cooling efficiency is improved by expanding the collision area by the cooling protrusion 2250, iii) the cooling efficiency can be improved by increasing the air curtain effect by discharging through the cooling hole 2003 close to the leading edge LE side.

[0089] FIG. 9 is a plan view showing an enlarged view of a portion B of FIG. 4, and is a view showing a part of the airfoil according to the fourth embodiment of the present invention.

[0090] Referring to FIG. 9, the cooling channel portion 2200 of the present embodiment includes a collision jet hole 2210, an internal cooling channel 2220, a cooling channel outlet 2230, and a second cooling fin 2260. Since the collision jet hole 2210, the internal cooling channel 2220, and the cooling channel outlet 2230 are substantially the same as those of the first embodiment described above, repeated description will be omitted.

[0091] The second cooling fin 2260 can generate a turbulent flow in the flow of the cooling fluid flowing inside the internal cooling channel 2220. And the second cooling fin 2260 can improve the rigidity of the structure of the airfoil wall surface (pressure surface, suction surface) whose rigidity has been weakened by the internal cooling channel 2220. And the second cooling fin 2260 can increase the heat transfer area and improve the cooling efficiency by the cooling fluid.

[0092] Specifically, the second cooling fin 2260 may be a fin structure formed across any one surface of the internal cooling channel 2220 and its opposite surface. The fin structure can be formed in various shapes such as a polygonal shape, a circular shape, an X shape, etc. The second cooling fin 2260 may be formed between any one collision jet hole 2210 and its adjacent collision jet hole 2210.

[0093] According to the airfoil according to the fourth embodiment of the present invention as described above, the cooling efficiency can be improved by i) cooling by the collision of the cooling fluid with the internal cooling channel 2220, ii) improvement of the cooling efficiency by the turbulent flow caused by the second cooling fin 2260, iii) increase of the air curtain effect by the discharge through the cooling hole 2003 close to the leading edge LE side, etc.

[0094] FIG. 10 is a plan view showing an enlarged view of a portion B of FIG. 4, and is a view showing a part of an airfoil according to a fifth embodiment of the present invention.

[0095] Referring to FIG. 10, the cooling channel portion 2200 of the fifth embodiment includes a collision jet hole 2210, an internal cooling channel 2220, a cooling channel outlet 2230, and a collision cavity 2270. Since the collision jet hole 2210, the internal cooling channel 2220, and the cooling channel outlet 2230 are substantially the same as those in the first embodiment described above, repeated description is omitted. The fifth embodiment can be applied in combination with at least any one of the first to fourth embodiments described above.

[0096] The collision cavity 2270 includes a collision guiding member 2271 having a predetermined shape formed in the internal space of the sub-cavity 2300, and a collision guiding inlet 2272 formed by opening a part of the collision guiding member 2271.

[0097] The collision guiding member 2271 may be a polyhedral shape formed to surround the inlet 2003a of the cooling hole, or a plate member formed in a hemispherical shape. The collision guiding inlet 2272 may be formed by opening the upper part of the inlet 2003a of the cooling hole in the plate member.

[0098] The collision cavity 2270 causes the cooling fluid discharged through the cooling channel outlet 2230 to collide again with the wall surface forming the suction surface 2001 or the pressure surface 2002 before being discharged to the outside through the cooling hole 2003, so that secondary collision cooling is performed.

[0099] At this time, in order to smoothly discharge the cooling fluid after the secondary collision, an inclined surface 2273 having an upper wide and lower narrow shape may be formed around the inlet 2003a of the cooling hole.

[0100] According to the airfoil according to the fifth embodiment of the present invention as described above, in addition to the effects of the first to fourth embodiments described above, the cooling efficiency can be further improved by performing secondary collision cooling with the collision cavity 2270 before the cooling fluid is discharged through the cooling hole 2003.

[0101] The internal structure of the airfoil (first to fifth embodiments) described above, which could not have been manufactured in the past due to its complex shape, can be manufactured as an integrated continuous structure airfoil by applying the recently developed metal 3D printing technology, rather than manufacturing and assembling the components separately.

[0102] As described above, the embodiments of the present invention have been explained. However, those with ordinary knowledge in the relevant technical field can make various modifications and changes to the present invention by adding, changing, deleting, or adding components, etc., without departing from the idea of the present invention described in the claims, and this is also included within the scope of the rights of the present invention.

Explanation of Reference Numerals

[0103] 1000: Gas turbine 1100: Compressor 1200: Combustor 1300: Turbine 2000: Airfoil 2001: Suction surface, 2002: Pressure surface 2003: Cooling hole 2100: Main cavity 2200: Cooling flow path section 2210: Impinging jet hole, 2220: Internal cooling flow path 2230: Cooling flow path outlet, 2240: First cooling fin 2250: Cooling protrusion, 2260: Second cooling fin 2270: Impinging cavity

Claims

1. An intake surface and a pressure surface formed with cooling holes, at least one main cavity formed in an internal space formed by the intake surface and the pressure surface, into which a cooling fluid flows, an internal cooling flow path formed inside a wall body forming the intake surface and the pressure surface, a plurality of collision jet holes formed on the inner surfaces of the intake surface and the pressure surface, for causing the cooling fluid to flow into the internal cooling flow path for collision cooling, a sub-cavity formed so as to surround an internal cooling flow path outlet formed at an end of the internal cooling flow path, for communicating the internal cooling flow path outlet and an inlet of the cooling hole, an airfoil including the above.

2. The plurality of collision jet holes are formed along the span direction on the inner surfaces of the intake surface and the pressure surface, the collision jet holes are formed on the trailing edge side, and the internal cooling flow path outlet is formed on the leading edge side, The airfoil according to claim 1, wherein the plurality of sub-cavities are formed along the span direction on the inner surfaces of the intake surface and the pressure surface.

3. The airfoil according to claim 1, including a first cooling fin protruding from one surface to the other surface inside a wall body forming the internal cooling flow path and formed separated from the other surface.

4. The airfoil according to claim 3, wherein the first cooling fin is formed between any one collision jet hole and an adjacent collision jet hole.

5. The airfoil according to claim 1, including a cooling protrusion protruding from the other surface to one surface inside a wall body forming the internal cooling flow path and formed below the collision jet hole.

6. The airfoil according to claim 1, including a second cooling fin formed by connecting one surface and the other surface inside a wall body forming the internal cooling flow path.

7. The airfoil according to claim 6, wherein the second cooling fin is formed between any one collision jet hole and an adjacent collision jet hole.

8. The airfoil according to claim 1, further including a collision cavity configured such that the cooling fluid discharged through the internal cooling flow path outlet collides with a surface of a wall body forming the intake surface or the pressure surface before being discharged to the outside through the cooling hole.

9. a compressor for compressing the incoming air, a combustor for mixing and burning the air compressed by the compressor and fuel, A turbine including a turbine vane that generates power using combustion gas from the combustor and guides the combustion gas on a combustion gas path through which the combustion gas passes, and a turbine blade that rotates by the combustion gas on the combustion gas path. At least one of the turbine vane or the turbine blade includes an airfoil, and the airfoil has a suction surface and a pressure surface on which cooling holes are formed, at least one main cavity formed in an internal space formed by the suction surface and the pressure surface and into which a cooling fluid flows, an internal cooling flow path formed inside a wall forming the suction surface and the pressure surface, a plurality of impingement jet holes formed on the inner surfaces of the suction surface and the pressure surface to allow the cooling fluid to flow into the internal cooling flow path for impingement cooling, a sub-cavity formed to surround an internal cooling flow path outlet formed at an end of the internal cooling flow path and communicating the internal cooling flow path outlet with an inlet of the cooling hole. A gas turbine including these components.

10. The impingement jet holes are formed in plurality along the span direction on the inner surfaces of the suction surface and the pressure surface. The impingement jet holes are formed on the trailing edge side, and the internal cooling flow path outlet is formed on the leading edge side. The gas turbine according to claim 9, wherein the sub-cavities are formed in plurality along the span direction on the inner surfaces of the suction surface and the pressure surface.

11. Including first cooling fins protruding from one surface to the other surface direction inside a wall forming the internal cooling flow path and formed spaced apart from the other surface. The gas turbine according to claim 9, wherein the first cooling fins are formed between any one impingement jet hole and an adjacent impingement jet hole.

12. The gas turbine according to claim 9, including cooling protrusions protruding from the other surface to one surface direction inside a wall forming the internal cooling flow path and formed below the impingement jet holes.

13. The gas turbine according to claim 9, including second cooling fins formed by connecting one surface and the other surface inside a wall forming the internal cooling flow path.

14. The gas turbine according to claim 13, wherein the second cooling fins are formed between any one impingement jet hole and an adjacent impingement jet hole.

15. The gas turbine according to claim 9, further comprising a collision cavity configured such that the cooling fluid discharged through the outlet of the internal cooling flow path collides with the surface of the wall forming the suction surface or the pressure surface before being discharged to the outside through the cooling hole.

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