KR20190036205A - Gas Turbine - Google Patents

Abstract

Disclosed is a gas turbine. The gas turbine according to an embodiment of the present invention comprises: a turbine vane (33) provided at the gas turbine; an end wall (38) connected to a hub (31) and a tip (32) of the turbine vane (33); and a spray unit (300) formed at the end wall (38) and spraying cooling air towards a leading edge (34) so as to prevent a secondary flow.

Description

Gas Turbine

The present invention relates to a turbine vane provided in a gas turbine, and more particularly, to a gas turbine for efficient cooling at a leading edge where film cooling of the turbine vane is unfavorable.

BACKGROUND ART Generally, a gas turbine is a type of internal combustion engine that converts thermal energy into mechanical energy by injecting high-temperature and high-pressure combustion gases produced by mixing fuel into compressed air at a high pressure in a compressor, and rotating the turbine.

In order to construct such a turbine, a plurality of turbine rotor disks in which a plurality of turbine blades are arranged on the outer circumferential surface are configured in a multi-stage so that the high-temperature and high-pressure combustion gases are allowed to pass through the turbine blades.

A membrane cooling method for cooling the surface of a turbine vane of a gas turbine used in this way is generally used and will be described with reference to the drawings.

Referring to FIG. 1 of the accompanying drawings, a turbine vane is moved as shown in FIG.

The hot gas moves to the turbine vane 3 and a flow of movement of the secondary vortex is generated as indicated by arrows at the leading edge 3a. The secondary vortex flow is generated along the end wall 3c in the form of a vortex flow as shown by the arrows in the drawing on the pressure face 3d and suction face 3b.

For example, in the pressure surface 3d, a movement flow outwardly from the surface of the turbine vane 3 is caused, which causes a detrimental effect on the film cooling efficiency.

It is advantageous that the cooling performance of the surface of the turbine vane 3 is kept constant. However, when the above-mentioned moving flow is generated, the cooling air injected to the surface of the turbine vane 3 is peeled off and the turbine vane 3 The surface temperature of the substrate may increase, thereby causing thermal stress to concentrate or deformation due to thermal fatigue.

Therefore, in order to improve the efficiency of the gas turbine equipped with the turbine vane 3, it is required to develop a technology for stabilizing the movement of the hot gas.

Korean Patent Publication No. 10-2015-0008749

Embodiments of the present invention provide a gas turbine that minimizes the flow of secondary vortex generated in the turbine vane to improve the film cooling performance.

A gas turbine according to a first embodiment of the present invention includes a turbine vane (33) provided in a gas turbine; An end wall (38) connected to the hub (31) and the tip (32) of the turbine vane (33); And a jetting part 300 formed in the end wall 38 and spraying cooling air toward the leading edge 34 to prevent secondary flow.

The jetting unit 300 is positioned facing the hub 31 of the turbine vane 33 and the rounded portion 37 extending from the tip 32.

The jetting unit 300 includes a first jetting unit 310 which is opened toward the leading edge 34 adjacent to the rounding unit 37 or the rounding unit 37 in the front surface of the leading edge 34; A second jetting portion 320 opened toward one side of the leading edge 34; And a third jetting part 330 opened toward the other side of the leading edge 34.

The second and third sprayers 320 and 330 are disposed symmetrically with respect to the front surface of the leading edge 34.

The second and third spray units 320 and 330 are disposed at predetermined intervals from the front of the leading edge 34 to a position orthogonal to the left and right sides.

The first ejecting portions 310 are disposed to be shifted from each other toward the front of the leading edge 34.

The second to third jetting portions 310, 320 and 330 are disposed to be shifted from each other toward the suction surface 33b and the pressure surface 33a adjacent to the front of the leading edge 34. [

The first to third jetting portions 310, 320, and 330 are inclined at different inclination angles inside the end wall 38 toward the leading edge 34.

And the inclination angle is any one of an arbitrary inclination angle selected from 5 degrees to 50 degrees.

The first spraying part 310 injects cooling air toward different positions of the leading edge 34 adjacent to the hub 31 and the tip 32. [

The second and third sprayers 320 and 330 spray cooling air toward different positions of the suction surface 33b and the pressure surface 33a adjacent to the hub 31 and the tip 32 .

The first to third jetting portions 310, 320, and 330 are formed in the shape of a nozzle whose diameter decreases toward the leading edge 34.

The jetting unit 300 includes an auxiliary jetting unit 350 provided in the end wall 38 to jet the cooling air toward the suction surface 33b and the pressure surface 33a.

The auxiliary spraying part 350 is inclined toward the suction surface 33b and the pressure surface 33a.

The auxiliary spraying unit 350 is located in a section corresponding to the 2S / 3 position with respect to the leading edge 34 when the section from the leading edge 34 to the trailing edge 35 is tripled .

Embodiments of the present invention may weaken the flow of secondary vortex generated in a turbine vane to induce a stable flow of hot gas.

Embodiments of the present invention can stably maintain cooling performance on the leading edge, suction surface and pressure surface and improve aerodynamic performance of the turbine vane.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a flow of a hot gas moving along a conventional turbine vane; FIG.
2 is a longitudinal sectional view of a gas turbine equipped with a turbine vane according to the present embodiment.
3 is a perspective view showing a turbine vane according to a first embodiment of the present invention;
4 is a view showing a leading edge and a jetting portion of a turbine vane according to a first embodiment of the present invention;
5 is a cross-sectional view of a first jet portion provided in a turbine vane according to a first embodiment of the present invention;
6 is a perspective view illustrating an auxiliary injection unit provided in the turbine vane according to the first embodiment of the present invention;

Before describing the present invention, the configuration of a gas turbine will be described with reference to the drawings.

Referring to FIG. 2, the gas turbine is provided with a casing 10 forming an outer shape, and a diffuser is disposed at a rear side (reference right side in FIG. 2) of the casing 10 to discharge combustion gas passing through the turbine.

And a combustor 11 for supplying compressed air to the front side of the diffuser and burning the air.

Referring to the flow direction of the air, the compressor section 12 is located in front of the casing 10, and the turbine section 30 is provided in the rear.

A torque tube 14 is provided between the compressor section 12 and the turbine section 30 for transmitting the rotational torque generated from the turbine section 30 to the compressor section 12.

The compressor section 12 is provided with a plurality (for example, 14) of compressor rotor discs, each of which is fastened in a manner not to be axially spaced apart by a tie rod 15.

And the centers of the respective compressor rotor discs are aligned along the axial direction with the tie rods (15) passing through them. A flange coupled to the adjacent rotor disk such that relative rotation is not possible, is formed in the vicinity of the outer periphery of the compressor rotor disk so as to protrude in the axial direction.

A plurality of blades are radially coupled to the outer peripheral surface of the compressor rotor disk. Each of the blades has a dovetail portion and is fastened to the compressor rotor disk.

The dovetail part has a tangential type and an axial type. This can be selected according to the required structure of the commercial gas turbine. In some cases, the blade may be fastened to the rotor disk by using a fastening device other than the dovetail.

The tie rod 15 is disposed to pass through the center of the plurality of compressor rotor discs. One end of the tie rod 15 is fastened in the compressor rotor disk located at the uppermost position, and the other end is fixed to the torque tube.

The shape of the tie rods may be variously configured depending on the gas turbine, and therefore, the shape of the tie rods is not necessarily limited to the shapes shown in the drawings.

One tie rod may pass through the central portion of the rotor disk, or a plurality of tie rods may be arranged in a circumferential direction, or a combination thereof may be used.

Although not shown, the compressor of the gas turbine may be provided with a vane serving as a guide pin at the next position of the diffuser to increase the flow pressure of the fluid entering the combustor inlet to the design flow angle after increasing the pressure of the fluid And is called a desworler.

The combustor 11 mixes and combusts the introduced compressed air with the fuel to produce a high-temperature high-temperature and high-pressure combustion gas, and the combustion gas temperature is increased to the heat resistance limit at which the combustor and the turbine component can withstand .

A plurality of combustors constituting the combustion system of the gas turbine may be arranged in a casing formed in a cell shape. The combustor includes a burner including a fuel injection nozzle and the like, a combustor liner forming a combustion chamber, And a transition piece as a connection part between the combustor and the turbine.

Specifically, the liner provides a combustion space in which the fuel injected by the fuel nozzle is mixed with the compressed air of the compressor and burned. Such a liner may include a flame passage providing a combustion space in which fuel mixed with air is combusted, and a flow sleeve forming an annular space surrounding the flame tube. A fuel nozzle is coupled to the front end of the liner, and a spark plug is coupled to the side wall.

On the other hand, a transition piece is connected to the rear end of the liner so that the combustion gas burned by the spark plug can be sent to the turbine side.

The transition piece is cooled by the compressed air supplied from the compressor to the outer wall portion so as to prevent breakage by the high temperature of the combustion gas.

To this end, the transition piece is provided with cooling holes for blowing air inward, and the compressed air flows to the liner side after cooling the body inside the holes through the holes.

The cooling air cooled by the transition piece flows through the annular space of the liner. Compressed air is supplied to the outer wall of the liner from the outside of the flow sleeve through the cooling holes provided in the flow slip part, .

In general, in a turbine, high-temperature and high-pressure combustion gases from a combustor expand and convert impulsive and repulsive forces into rotational energy of a turbine to mechanical energy.

The mechanical energy obtained from the turbine is supplied to the compressor as the energy required to compress the air and the remainder is used to drive the generator to produce power.

In the turbine, a plurality of stator blades and rotor blades are alternately arranged and formed in the vehicle room, and the rotor is driven by the combustion gas to rotate the output shaft to which the generator is connected.

To this end, the turbine section 30 is provided with a plurality of turbine rotor discs. Each of these turbine rotor disks is basically similar in shape to the compressor rotor disk.

The turbine rotor disk also includes a plurality of turbine vanes 33 disposed radially and having flanges for engaging adjacent turbine rotor disks. The turbine vane 33 may also be coupled to the turbine rotor disk in a dovetail fashion.

In the gas turbine having such a structure, the introduced air is compressed in the compressor section 12, burned in the combustor 11, then moved to the turbine section 30 to drive the turbine, Lt; / RTI >

A typical method for increasing the efficiency of the gas turbine is to increase the temperature of the gas flowing into the turbine section 30, but in this case, the inlet temperature of the turbine section 30 is increased.

In addition, a problem arises in the turbine vane 33 provided in the turbine section 30, and the temperature of the turbine vane 33 is locally increased to generate a thermal stress, and the thermal stress is maintained for a long time The turbine vane 33 may be destroyed due to a creep phenomenon.

A gas turbine according to a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 3 is a perspective view illustrating a turbine vane according to a first embodiment of the present invention, and FIG. 4 is a view illustrating a leading edge and a jetting section of a turbine vane according to the first embodiment of the present invention.

3 to 4, the gas turbine according to the first embodiment of the present invention requires stable cooling of the outer circumferential surface when hot gas is supplied to the outer circumferential surface of the turbine vane 33.

The gas turbine according to the first embodiment of the present invention includes a turbine vane 33 provided in the gas turbine and an end wall 38 connected to the hub 31 and the tip 32 of the turbine vane 33, And a jetting part 300 formed on the leading edge 38 and spraying cooling air toward the leading edge 34 to prevent secondary flow.

In this embodiment, the flow of the secondary vortex is induced along the suction surface 33b and the pressure surface 33a after the hot gas supplied to the turbine vane 33 collides with the leading edge 34, Injection section 300 is formed to minimize the loss of aerodynamic performance due to passage vortex in 1,2nd month 38a, 38b.

The jetting unit 300 is positioned facing the hub 31 of the turbine vane 33 and the rounded portion 37 extending from the tip 32.

The turbine vane 33 includes a leading edge 34 for observing the leading end of the hot gas into which the hot gas flows, a suction surface 33b and a pressure surface 33a extending toward the trailing end from the leading edge 34, And a trailing edge 35 formed at the end of the pressure surface 33a and the suction surface 33b.

The end wall 38 includes a first end wall 38a connected to the hub 31 and a second end wall 38b connected to the tip 32. [ Since the cooling air flows into the end wall 38, the cooling air can be supplied to the leading edge 34 through the spray part 300.

The leading edge 34 is a point where the hot gas is continuously supplied to the turbine vane 33 so that the temperature of the hot gas is continuously maintained and the moving path of the hot gas moving to the suction surface 33b and the pressure surface 33a .

For example, after the hot gas passes through the leading edge 34, a moving path that is in close contact with the suction surface 33b and the pressure surface 33a of the turbine vane 33 is maintained, When cooled by the film cooling of the film cooling unit 100, the turbine vane 33 can simultaneously improve the stable moving flow of the hot gas and the cooling efficiency.

The present embodiment is provided with a sprayer 300 for this purpose so that the problem of the secondary vortex generated when the hot gas is branched at the leading edge 34 is minimized, A first jetting part 310 opened toward the leading edge 34 adjacent to the round part 37 or a second jetting part 320 opened toward one side of the leading edge 34, And a third jetting part 330 opened toward the other side of the leading edge 34.

The first jetting part 310 is composed of a plurality of passages communicating with the inside of the first and second end walls 38a and 38b. The hot gas is moved in the directions shown by the arrows toward the first end wall 38a and the second end wall 38b, respectively, after being contacted with the leading edge 34.

The hot gas is deformed into a spiral shape immediately after the collision with the leading edge 34 so as to come into close contact with the suction surface 33b and move in a direction away from the pressure surface 33a, The vortex flow of the helical form is weakened by using the cooling air and is guided to the moving flow moving along the surface of the first and second end walls 38a and 38b or the round portion 37. [

For this purpose, the first jetting portions 310 are disposed to be shifted from each other toward the front of the leading edge 34. The first spraying part 310 may have various arrangements. For example, the first spraying part 310 is opened at different positions so that the cooling air does not overlap each other.

The hot gas is changed in a moving flow (a direction) descending toward the hub 31 and a moving flow (b direction) rising toward the tip 32 after contacting with the leading edge 34, Toward the first end wall 38a and toward the tip 32 toward the second end wall 38b, respectively.

The present embodiment weakens the flow of air flowing down by the cooling air jetted from the first to third jetting portions 310, 320 and 330 toward the hot gas moved to the first end wall 38a, To a flow in which a locus of a1 and a2 is generated.

The cooling air injected from the first, second, third, and third injectors 310, 320, and 330 weakens the flow of the airflow that is raised by the hot gas transferred to the second end wall 38b, a3 and a4 are generated.

The hot gas is changed to the moving flow adhered to the suction surface 33b and the pressure surface 33a before reaching the leading edge 34 and after the moving direction and flow are changed by the jetting section 300 The film cooling effect of the turbine vane 33 is increased and the loss of aerodynamic performance due to the passage vortex in the first and second end 38a, 38b is minimized.

The second and third sprayers 320 and 330 according to the present embodiment are arranged symmetrically with respect to the front surface of the leading edge 34. And the third jetting part 330 is disposed at a position facing the leading edge 34 and the pressure surface 33a adjacent to the leading edge 34. [ As shown in Fig.

The second and third spray units 320 and 330 are disposed at predetermined intervals from the front of the leading edge 34 to a position orthogonal to the left and right sides. Since the hot gas is branched and moved to the positions a1 and a3 at positions a and b after the collision with the leading edge 34, cooling air is injected at the positions so that the direction of movement of the hot gas is parallel to the suction surface 33b and the pressure surface 33a It is desirable to switch to the surface to minimize unnecessary secondary flow.

The first to third jetting parts 310, 320 and 330 are disposed in front of the leading edge 34 and in front of the leading edge 34 and adjacent to the suction surface 33b and the pressure surface 33a, Respectively. The first, second, third, and third sprayers 310, 320, and 330 may be advantageous to change the flow of the hot gas because the spray directions are opened toward different directions rather than overlapping each other.

In this case, since the cooling air is injected in the arrow direction after being sprayed by the first to third jetting parts 310, 320 and 330, the flow of hot gas can be changed in various directions, and the above-mentioned effect can be obtained.

The first to third jetting portions 310, 320, and 330 are inclined at different inclination angles inside the end wall 38 toward the leading edge 34. For example, the inclination angle may be any one of an arbitrary inclination angle selected from 5 degrees to 50 degrees.

The inclination angle can be changed to 5 degrees or 50 degrees depending on the injection position and can be changed according to the moving direction of the hot gas.

For example, the first spray portion 310 may be inclined at a first inclination angle, and the second and third spray portions 320 and 330 may be inclined at a second inclination angle.

The first spraying part 310 may be configured to spray cooling air toward different positions of the leading edge 34 adjacent to the hub 31 and the tip 32. [ The first injecting part 310 is composed of a plurality of unit injecting parts, and the positions of the first injecting part 310 and the first injecting part 310 are different from each other.

The second and third sprayers 320 and 330 can spray cooling air toward different positions of the suction surface 33b and the pressure surface 33a adjacent to the hub 31 and the tip 32 have.

When the hot gas is caused to move in different directions when moving along the suction surface 33b and the pressure surface 33a, in order to induce the optimal flow of the hot gas, the cooling air is sprayed to different positions as described above The moving flow of the secondary vortex can be weakened and the film cooling performance of the turbine vane 33 can be improved.

Referring to FIG. 5, the first to third jetting portions 310, 320, and 330 according to the present embodiment may have a nozzle shape having a reduced diameter toward the leading edge 34. In this case, the cooling air is increased toward the leading edge 34, which is advantageous to weaken the flow of air by the secondary vortex of the hot gas.

The first to third jetting portions 310, 320, and 330 may be configured such that the mode diameter is decreased or only the unit jet portion positioned at a specific position is reduced in diameter.

Referring to FIG. 6, the jetting unit 300 according to the present embodiment includes an auxiliary jetting part 331 provided in the end wall 38 to jet the cooling air toward the suction surface 33b and the pressure surface 33a, (350).

The auxiliary spraying part 350 is similar to the spraying part 300 except that the hot gas whose flow is primarily changed at the leading edge 34 is moved along the suction surface 33b and the pressure surface 33a It is possible to minimize the loss of aerodynamic performance due to passage vortex by injecting cooling air secondarily.

Particularly, since the flow of the hot gas in the turbine vane 33 becomes unstable on the pressure surface 33a, when the cooling air is further injected by using the auxiliary spraying portion 350, It is possible to induce a moving flow.

Since the auxiliary spraying part 350 has the same action effect as the pressure surface 33a on the suction surface 33b, the moving flow of the secondary vortex is weakened and the film cooling performance of the turbine vane 33 can be improved .

The auxiliary spraying part 350 may be inclined toward the suction surface 33b and the pressure surface 33a. The inclined angle of the auxiliary jetting section 350 is not particularly limited, but may be inclined toward the round section 37. [

The auxiliary spraying unit 350 is located in a section corresponding to the 2S / 3 position with respect to the leading edge 34 when the section from the leading edge 34 to the trailing edge 35 is tripled .

For example, when the section from the leading edge 34 to the trailing edge 35 is tripled, the curved section S may include a first bending section corresponding to the S / 3 position with respect to the leading edge 34, A second bending section S2 corresponding to the 2S / 3 position of the bending section S from the end of the first bending section S2 and a second bending section S2 corresponding to the second bending section S2 from the end of the second bending section S2, And a third bending section S3 corresponding to the remaining section to the trailing edge 35. [

The second bending section S2 corresponds to the suction surface 33b and the pressure surface 33a. The pressure surface 33a of the pressure bending section 33a extends in a streamlined round section toward the inside of the turbine vane 33 . Since the film cooling effect by the film cooling unit 100 is relatively low in the second bending section S2, the auxiliary jetting unit 350 is provided to improve the cooling effect.

Particularly, the position is a section in which a moving flow which can not be adhered to the surface of the pressure surface 33a is generated when the hot gas is moved along the surface of the pressure surface 33a, and the auxiliary dispensing part 350 is positioned at the above position Further cooling of the turbine vane 33 can lead to stable cooling of the membrane, thereby improving the cooling efficiency of the turbine vane 33.

33: turbine blade
34: Reading Edge
35: Trailing Edge
38: And the month
38a: 1st and 2nd month
38b: 2nd and 3rd month
100: film cooling unit
300:
310, 320, 330: 1st, 2nd,
S: bending section
S1, S2, S3: First to third bending sections

Claims (15)

A turbine vane (33) provided in the gas turbine;
An end wall (38) connected to the hub (31) and the tip (32) of the turbine vane (33); And
And a jetting portion (300) formed in the end wall (38) and spraying cooling air toward the leading edge (34) to prevent secondary flow. The method according to claim 1,
The jetting section 300 is positioned facing the hub 31 of the turbine vane 33 and the rounded portion 37 extending from the tip 32. 3. The method of claim 2,
The jetting unit 300 includes a first jetting unit 310 which is opened toward the leading edge 34 adjacent to the rounding unit 37 or the rounding unit 37 in the front surface of the leading edge 34;
A second jetting portion 320 opened toward one side of the leading edge 34;
And a third jetting portion (330) opening toward the other side of the leading edge (34). The method of claim 3,
And the second and third jetting portions (320, 330) are arranged symmetrically with respect to the front of the leading edge (34). The method of claim 3,
And the second and third spray units (320, 330) are disposed at predetermined intervals from the front of the leading edge (34) to a position orthogonal to the left and right sides. The method of claim 3,
Wherein the first jetting portion (310) is disposed to be offset from the front of the leading edge (34). The method of claim 3,
The second to third jetting portions 310, 320, and 330 are disposed to be offset from each other toward the suction surface 33b and the pressure surface 33a adjacent to the front of the leading edge 34. [ The method of claim 3,
Wherein the first to third jetting portions (310, 320, 330) are disposed at an inclination angle different from each other inside the end wall (38) toward the leading edge (34). 9. The method of claim 8,
Wherein the inclination angle is any one of an arbitrary inclination angle selected from 5 degrees to 50 degrees. The method of claim 3,
The first jetting portion (310) ejects cooling air toward different positions of the leading edge (34) adjacent to the hub (31) and tip (32). The method of claim 3,
The second and third jet generators 320 and 330 are connected to the hub 31 and the tip 32 and to the suction surface 33b and the pressure surface 33a, . The method of claim 3,
Wherein the first to third jetting portions (310, 320, 330) are in the form of a nozzle whose diameter is reduced toward the leading edge (34). The method of claim 3,
The jetting section 300 includes an auxiliary jetting section 350 provided in the end wall 38 to jet the cooling air toward the suction surface 33b and the pressure surface 33a. The method of claim 3,
The auxiliary jetting section 350 is positioned obliquely toward the suction surface 33b and the pressure surface 33a. 14. The method of claim 13,
The auxiliary spraying unit 350 is disposed at a position corresponding to the 2S / 3 position with respect to the leading edge 34 when the interval from the leading edge 34 to the trailing edge 35 is tripled Gas turbine.

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