KR20200132817A - Gas turbine including an external cooling system and cooling method thereof - Google Patents

Abstract

The present invention relates to a gas turbine and a cooling method thereof, wherein a cooling air supply circuit is not formed inside a central shaft of the gas turbine. The cooling air supply circuit is formed to bypass air by extracting the air from a compressor of the gas turbine, and at the same time, vanes and blades of the turbine are cooled by one cooling air circuit, so that the use amount of cooling air can be reduced and the amount of air can be freely controlled.

Description

Gas turbine including external cooling system and its cooling method {GAS TURBINE INCLUDING AN EXTERNAL COOLING SYSTEM AND COOLING METHOD THEREOF}

The present invention relates to a gas turbine including an external cooling system and a cooling method thereof, and more particularly, a cooling air supply flow path bypassing the outside of the gas turbine without a cooling air supply flow path is formed inside the central axis of the gas turbine. It is formed, and as the vanes and blades of the turbine are cooled by one cooling air flow path, the present invention relates to a gas turbine capable of reducing the amount of cooling air and freely adjusting the amount of air, and a cooling method thereof.

In general, a turbine is a machine that converts the energy of a fluid such as water, gas, steam, etc. into mechanical work. Usually, several blades or blades are planted on the circumference of a rotating body and steam or gas is blown thereto at high speed with impulsive or reaction force. A turbo-type machine that rotates is called a turbine.

Types of such turbines include a hydro turbine that uses the energy of high water, a steam turbine that uses the energy of steam, an air turbine that uses the energy of high pressure compressed air, and a gas that uses the energy of high temperature and high pressure gas. And turbines.

Among them, the gas turbine includes a compressor, a combustor, a turbine, and a rotor, and operates on the principle of combusting fuel through compressed air to generate powerful energy and to operate the turbine using this.

In this process, a plurality of combustors are provided in one power generation device, and a plurality of fuel supply nozzles are provided in the plurality of combustors. High-temperature flames are generated by injecting a mixture of fuel and air from one fuel supply nozzle, respectively, and the heat and temperature of the flames are transmitted to the turbine blades and other components of the power generation device.

At this time, even if each component is composed of a material with excellent heat resistance, the life expectancy of the mechanical device is reduced if it is exposed to excessive high temperature for a long period of time. To prevent this, some of the air compressed by the compressor is supplied to the turbine blade and the power generation device. By supplying to the component, it prevents the temperature from rising rapidly.

In the above case, the prior art took a method of supplying compressed air from a compressor including a plurality of rotating bodies to the turbine blades through a tube passing through the rotor (center shaft) of the gas turbine.

However, in the case of this method, there is a problem that the flow loss through the flow path inside the gas turbine rotor is large, and the consumption of cooling air is large in the gas turbine having a high turbine inlet temperature and compression ratio.

In addition, since the diameter of the central hole of the rotor is increased, and a space in which a separate tube is inserted is required to separate the space inside the rotor from the cooling air, there is a problem that the structural design of the central axis of the generator and other devices becomes complicated.

This soon led to a decrease in the aerodynamic efficiency of the compressor and turbine.

U.S. Patent Publication No. 4,113,406 (1978.09.12)

In the present invention, the cooling air supply flow path is not formed inside the central axis of the gas turbine, and a cooling air supply flow path bypassing the outside of the gas turbine is formed, and the vanes and blades of the turbine are one cooling air flow path. It is an object of the present invention to provide a gas turbine capable of reducing the amount of cooling air and freely adjusting the amount of air, and a cooling method thereof, as it is cooled by.

In the present invention, in order to achieve the above object, the cooling air supply flow path is not formed inside the central axis of the gas turbine, and the cooling air supply flow path is formed to bypass air by extracting air from the compressor of the gas turbine. At the same time, the turbine's vanes and blades are cooled by a single cooling air flow path.

Accordingly, it is possible to reduce the amount of cooling air used, and it is possible to freely control the amount of air.

The present invention for solving the above problems is a casing, a compressor disposed in the casing, and a compressor for sucking air and compressing it at high pressure, and a combustor for mixing and combusting the air compressed by the compressor with fuel, A turbine for generating electric power by rotating a plurality of turbine blades using high-temperature and high-pressure combustion gases discharged from the combustor, and for extracting air to the outside of the casing at different positions of the compressor and supplying it to the turbine. It provides a gas turbine including a plurality of external cooling flow paths and an outlet cooling flow path for extracting air from the outlet of the compressor and supplying it to the turbine.

In addition, the turbine includes the plurality of turbine blades, and a plurality of turbine vanes fixed to the casing and alternately disposed with the turbine blades, and at least one of the turbine blade and turbine vane pair located at the same end. The cooling flow path may further include at least one connection cooling flow path that is connected and formed to communicate with each other.

At this time, the outlet cooling flow path supplies air to a first-stage turbine vane of the plurality of turbine vanes and a first-stage turbine blade of the plurality of turbine blades, and the plurality of external cooling flow paths include the first-stage turbine vane. Air can be supplied to at least one turbine blade of at least one of the plurality of turbine vanes, except for the turbine blades of the plurality of turbine blades excluding the first-stage turbine blade, and the turbine blades of the stage where the connection cooling channel is not formed. have.

The outlet cooling passage includes an outlet outer cooling passage for supplying air to the first-stage turbine vane and an outlet inner cooling passage for supplying air to the first-stage turbine blade, and the plurality of external cooling passages, 4 A first external cooling channel for supplying air to the turbine vane and the fourth-stage turbine blade, a second external cooling channel for supplying air to the third-stage turbine vane, and a third for supplying air to the second-stage turbine vane It includes an external cooling flow path, and the connection cooling flow path may be formed on the turbine blade and turbine vane pairs of the second and third stages, respectively.

Alternatively, the outlet cooling flow path supplies air to a first-stage turbine vane among the plurality of turbine vanes and a first-stage and second-stage turbine blade of the plurality of turbine blades, and the plurality of external cooling flow paths, the first stage At least one turbine of at least one of the plurality of turbine vanes excluding the turbine vane, and at least one of the turbine blades of the plurality of turbine blades excluding the first-stage and second-stage turbine blades in which the connection cooling passage is not formed Air can be supplied to the blades.

The outlet cooling passage supplies air to an outlet outer cooling passage for supplying air to the first-stage turbine vane, a first outlet inner cooling passage for supplying air to the first-stage turbine blade, and the second-stage turbine blade It includes a second outlet inner cooling flow path for, and the plurality of external cooling flow paths, a first external cooling flow path for supplying air to the fourth-stage turbine vane and the fourth-stage turbine blade, and supplying air to the third-stage turbine vane And a second external cooling passage for supplying air to the second-stage turbine vane and a third external cooling passage for supplying air to the second-stage turbine vane, and the connection cooling passage may be formed in a pair of the turbine blade and the turbine vane of the third stage.

In this case, the first to third external cooling flow paths may be extracted from different positions of the compressor, but may be sequentially extracted from a distant position to a position close to the turbine.

In addition, a cooling unit for cooling air flowing in at least one of the plurality of external cooling flow paths and the cooling flow path inside the outlet may be further included.

The cooling unit may cool the air flowing in each flow path to different temperatures.

The cooling unit may include a second cooler disposed on the second external cooling channel, a third cooler disposed on the third external cooling channel, and a fourth cooler disposed on the cooling channel inside the outlet. .

In addition, the cooling unit may further include a first cooler disposed on the first external cooling channel.

At least one cooling air control valve may be provided on an inlet or a flow path of the first to third external cooling channels.

In addition, at least one cooling air control valve may be provided on the inlet or flow path of the outlet outer cooling passage and the outlet inner cooling passage.

The connection cooling passage may be connected through the lower end of the turbine blade and the turbine vane located at the same end so that air enters the lower side of the turbine blade.

The cooling passage inside the outlet may be formed through a lower end of the turbine blade so that air enters the lower interior of the turbine blade.

In addition, a pre-swirler is provided in at least one of a position where air enters the lower side of the turbine blade among the cooling passages inside the outlet, and a position where air enters the lower side of the turbine blade among the connection cooling passages. Each may be provided.

In addition, a sealing unit may be provided at at least one of a position where air enters the lower side of the turbine blade of the outlet inner cooling passage and a position of the connection cooling passage where air enters the lower side of the turbine blade. .

In addition, in the present invention, in a gas turbine cooling method including a casing, a compressor, a combustor and a turbine disposed in the casing, air is extracted to the outside of the casing at different positions of the compressor and supplied to the turbine. It provides a cooling method for a gas turbine comprising: supplying external cooling air and supplying cooling air to the turbine by extracting air from the outlet of the compressor.

In this case, the air supplied by the external cooling air supply step may cool the turbine blade and the turbine vane pair of the turbine positioned at the same stage at least one.

In addition, in the supplying of the external cooling air, at least one cooling air provided on an inlet or a flow path of a plurality of external cooling channels for supplying air to the turbine by extracting air from different locations of the compressor to the outside of the casing It may include a flow rate control step of adjusting the flow rate of the cooling air through the control valve.

According to a gas turbine including an external cooling system of the present invention and a cooling method thereof, a cooling air supply flow path is formed to extract air from the compressor of the gas turbine and bypass it to the outside, and at the same time, the vanes and blades of the turbine ) Is cooled by one cooling air flow path, it is possible to reduce the amount of cooling air used, and freely adjust the amount of cooling air for each cooling blade/vane of the turbine.

In addition, air in a plurality of external cooling passages and an outlet inner cooling passage may be cooled and supplied at different temperatures by using a plurality of coolers.

In addition, it is possible to increase the cooling effect by applying a pre-swirler and sealing structure for each turbine blade end of the turbine.

Ultimately, the design point and partial load performance of the gas turbine can be improved.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a cross-sectional view showing a schematic structure of a gas turbine according to an embodiment of the present invention.
2 is a partial cross-sectional view showing an external cooling system according to the first embodiment of the gas turbine of FIG. 1;
3 is a partial cross-sectional view showing an external cooling system according to a second embodiment of the gas turbine of FIG. 1.
4 is an enlarged cross-sectional view showing a part of the internal structure of the gas turbine of FIG. 1;
Figure 5 is a perspective view showing an enlarged free swirler in Figure 4;

Hereinafter, preferred embodiments of a gas turbine including an external cooling system of the present invention and a cooling method thereof will be described with reference to FIGS. 1 to 5.

In addition, terms to be described later are terms defined in consideration of functions in the present invention and may vary according to the intention or custom of users and operators, and the following examples do not limit the scope of the present invention, It is merely illustrative of the components presented in the claims.

In order to clearly describe the present invention, parts irrelevant to the description have been omitted, and the same reference numerals are assigned to the same or similar components throughout the specification. Throughout the specification, when a certain part "includes" a certain component, it means that other components may be further provided without excluding other components unless otherwise stated.

1 is a cross-sectional view showing a schematic structure of a gas turbine according to an embodiment of the present invention, FIG. 2 is a partial cross-sectional view showing an external cooling system according to a first embodiment of the gas turbine of FIG. 1, and FIG. A partial cross-sectional view showing an external cooling system according to a second embodiment of the gas turbine of 1, FIG. 4 is an enlarged cross-sectional view of a part of the internal structure of the gas turbine of FIG. 1, and FIG. 5 is a pre-swirler in FIG. It is an enlarged perspective view.

Hereinafter, a gas turbine according to an embodiment of the present invention will be described with reference to FIG. 1.

The gas turbine 1 according to an embodiment of the present invention comprises a casing 100, a compressor 200 disposed in the casing 100, and compressing air to a high pressure by suctioning air, and the compressor 200. A plurality of combustors 300 for mixing and combusting the compressed air by means of) and the high-temperature and high-pressure combustion gases discharged from the combustor 300 are used to rotate a plurality of turbine blades to generate electric power. It may be made including a turbine 400.

The casing 100 includes a compressor casing 102 accommodating the compressor 200, a combustor casing 103 accommodating the combustor 300, and a turbine casing 104 accommodating the turbine 400 can do. However, the present invention is not limited thereto, and the compressor casing, the combustor casing, and the turbine casing may be integrally formed.

Here, the compressor casing 102, the combustor casing 103, and the turbine casing 104 may be sequentially arranged from an upstream side to a downstream side in a fluid flow direction.

A rotor (center shaft) 50 is rotatably provided inside the casing 100, and a generator (not shown) is interlocked with the rotor 50 for power generation, and the turbine is located at the downstream side of the casing 100. A diffuser for discharging the combustion gas passing through 400 may be provided.

The rotor 50 is accommodated in a compressor rotor disk 52 accommodated in the compressor casing 102, a turbine rotor disk 54 accommodated in the turbine casing 104, and the combustor casing 103, and the compressor A torque tube 53 connecting the rotor disk 52 and the turbine rotor disk 54, the compressor rotor disk 52, the torque tube 53, and a tie rod fastening the turbine rotor disk 54 ( 55) and a fixing nut 56 may be included.

The compressor rotor disk 52 may be formed in a plurality (for example, 14 sheets), and the plurality of compressor rotor disks 52 may be arranged along the axial direction of the rotor 50. That is, the compressor rotor disk 52 may be formed in multiple stages.

In addition, each of the compressor rotor disks 52 may be formed in a substantially disk shape, and a compressor blade coupling slot coupled to a compressor blade 220 to be described later may be formed at an outer peripheral portion.

The turbine rotor disk 54 may be formed similar to the compressor rotor disk 52. That is, the turbine rotor disk 54 may be formed in plural, and the plurality of turbine rotor disks 54 may be arranged along the axial direction of the rotor 50. That is, the turbine rotor disk 54 may be formed in multiple stages.

In addition, each of the turbine rotor disks 54 may be formed in a substantially disk shape, and a turbine blade coupling slot coupled with a turbine blade 420 to be described later may be formed at an outer peripheral portion.

The torque tube 53 is a torque transmission member that transmits the rotational force of the turbine rotor disk 54 to the compressor rotor disk 52, and one end is the highest in the flow direction of air among the plurality of compressor rotor disks 52. It is coupled to a compressor rotor disk positioned at a downstream end, and the other end may be coupled to a turbine rotor disk positioned at an uppermost end in the flow direction of the combustion gas among the plurality of turbine rotor disks 54. Here, a protrusion is formed in each of one end and the other end of the torque tube 53, and a groove engaging with the protrusion is formed in each of the compressor rotor disk 52 and the turbine rotor disk 54, and the torque tube Relative rotation of 53 to the compressor rotor disk 52 and the turbine rotor disk 54 can be prevented.

In addition, the torque tube 53 may be formed in a hollow cylinder shape so that the air supplied from the compressor 200 passes through the torque tube 53 and flows to the turbine 400.

At this time, the torque tube 53 is strongly formed in deformation and distortion due to the characteristics of a gas turbine that is continuously operated for a long period of time, and can be easily assembled and disassembled for easy maintenance.

The tie rod 55 is formed to pass through the plurality of compressor rotor disks 52, the torque tube 53, and the plurality of turbine rotor disks 54, and one end of the plurality of compressor rotor disks 52 Based on the turbine rotor disk, which is fastened in the compressor rotor disk located at the uppermost end in the flow direction of the heavy air, and the other end is located at the lowest end in the flow direction of the combustion gas among the plurality of turbine rotor disks 54. It protrudes to the opposite side of the compressor 200 and may be fastened with the fixing nut 56.

Here, the fixing nut 56 pressurizes the turbine rotor disk 54 located at the lowermost end toward the compressor 200, and the compressor rotor disk 52 located at the uppermost end and the lowermost end As the distance between the positioned turbine rotor disks 54 decreases, a plurality of the compressor rotor disks 52, the torque tubes 53, and the plurality of turbine rotor disks 54 increase in the axial direction of the rotor 50 Can be compressed into Accordingly, the axial movement and relative rotation of the plurality of compressor rotor disks 52, the torque tube 53, and the plurality of turbine rotor disks 54 can be prevented.

Meanwhile, in the present embodiment, one tie rod is formed to pass through the centers of the plurality of compressor rotor disks, the torque tube, and the plurality of turbine rotor disks, but is not limited thereto. That is, separate tie rods may be provided on the compressor side and the turbine side, respectively, and a plurality of tie rods may be radially disposed along the circumferential direction, and a mixture thereof may be used.

The rotor 50 according to this configuration may have both ends rotatably supported by bearings, and one end may be connected to a drive shaft of the generator.

The compressor 200 includes a compressor blade 220 that is rotated together with the rotor 50 and a compressor vane 240 fixedly installed in the casing 100 to align the flow of air introduced into the compressor blade 220. ) Can be included.

The compressor blade 220 is formed in plural, the plurality of compressor blades 220 are formed in a plurality of stages along the axial direction of the rotor 50, and the plurality of compressor blades 220 are formed in each stage. It may be formed radially along the rotation direction of the rotor 50.

That is, the root portion 222 of the compressor blade 220 is coupled to the compressor blade coupling slot of the compressor rotor disk 52, and the root portion 222 is the compressor blade 220 is the compressor blade coupling slot It may be formed in a fir-tree shape to prevent the rotor 50 from being separated from the rotor in the radial direction of rotation.

In this case, the compressor blade coupling slot may be formed in a fir shape so as to correspond to the root portion 222 of the compressor blade.

In the present embodiment, the compressor blade root portion 222 and the compressor blade coupling slot are formed in a fir shape, but are not limited thereto and may be formed in a dovetail shape. Alternatively, the compressor blade may be fastened to the compressor rotor disk by using a fastening device other than the above, for example, a fastener such as a key or a bolt.

Here, the compressor rotor disk 52 and the compressor blade 220 are typically combined in a tangential type or an axial type. In this embodiment, the compressor blade root portion 222 ) Is formed in a so-called axial type shape that is inserted in the compressor blade coupling slot along the axial direction of the rotor 50 as described above. Accordingly, a plurality of the compressor blade coupling slots according to the present embodiment may be formed, and the plurality of compressor blade coupling slots may be radially arranged along the circumferential direction of the compressor rotor disk 52.

The compressor vanes 240 may be formed in plural, and the plurality of compressor vanes 240 may be formed in a plurality of stages along the axial direction of the rotor 50. Here, the compressor vanes 240 and the compressor blades 220 may be alternately arranged along the air flow direction.

In addition, the plurality of compressor vanes 240 may be radially formed in each stage along the rotation direction of the rotor 50.

The combustor 300 mixes and combusts the air introduced from the compressor 200 with fuel to produce a high-energy high-temperature and high-pressure combustion gas, and burns to a heat resistance limit that the combustor and the turbine can withstand through an isostatic combustion process. It may be formed to increase the gas temperature.

Specifically, the combustor 300 may be formed in plural, and the plurality of combustors 300 may be arranged in the combustor casing along the rotation direction of the rotor 50.

In addition, each of the combustors 300 includes a liner through which air compressed by the compressor 200 is introduced, a burner that injects and combusts fuel into the air introduced into the liner, and a combustion gas generated by the burner to the turbine. It may include a guiding transition piece.

The liner may include a flame barrel forming a combustion chamber, and a flow sleeve surrounding the flame barrel and forming an annular space.

The burner includes a fuel injection nozzle formed on a front end side of the liner to inject fuel into the air introduced into the combustion chamber, and a spark plug formed on a wall of the liner to ignite the air and fuel mixed in the combustion chamber. I can.

The transition piece may be formed such that the outer wall portion of the transition piece is cooled by air supplied from the compressor so as not to be damaged by the high temperature of the combustion gas.

That is, a cooling hole for injecting air into the transition piece is formed, and air may cool the main body inside through the cooling hole.

Meanwhile, the air cooled the transition piece flows into the annular space of the liner, and air from the outside of the flow sleeve is provided as cooling air through a cooling hole provided in the flow sleeve to collide with the outer wall of the liner. have.

Here, although not shown separately, between the compressor 200 and the combustor 300, a desworler serving as a guide blade is provided between the compressor 200 and the combustor 300 to adjust the flow angle of the air introduced into the combustor 300 to the design flow angle. Can be formed.

Next, the turbine 400 may be formed similar to the compressor 200.

That is, the turbine 400 is a turbine blade 420 rotated together with the rotor 50 and a turbine vane fixedly installed on the casing 100 to align the flow of air introduced into the turbine blade 420 (440) may be included.

The plurality of turbine blades 420 are formed, and the plurality of turbine blades 420 are formed in a plurality of stages along the axial direction of the rotor 50. In this embodiment, as shown in FIG. 1, the turbine blade 420 is configured in four stages, and the first stage turbine blade 424 in turn goes from an upstream side to a downstream side along the axial direction of the rotor 50. , A two-stage turbine blade 425, a three-stage turbine blade 426 and a four-stage turbine blade 427 are disposed. However, it is not limited thereto, and of course, a turbine blade having less than or exceeding 4 stages may be disposed. In addition, the plurality of turbine blades 420 may be radially formed along the rotation direction of the rotor 50 for each stage.

That is, the root portion 422 of the turbine blade 420 is coupled to the turbine blade coupling slot of the turbine rotor disk 54, and the root portion 422 is the turbine blade 420 is the turbine blade coupling slot It may be formed in a fir-tree shape to prevent the rotor 50 from being separated from the rotor in the radial direction of rotation.

In this case, the turbine blade coupling slot may be formed in a fir shape so as to correspond to the root portion 422 of the turbine blade.

In the present embodiment, the turbine blade root portion 422 and the turbine blade coupling slot are formed in a fir shape, but are not limited thereto and may be formed in a dovetail shape. Alternatively, the turbine blade may be fastened to the turbine rotor disk by using a fastening device other than the above, for example, a fastener such as a key or a bolt.

Here, the turbine rotor disk 54 and the turbine blade 420 are typically combined in a tangential type or an axial type. In this embodiment, the turbine blade root portion 422 ) Is formed in a so-called axial type shape that is inserted in the turbine blade coupling slot along the axial direction of the rotor 50 as described above. Accordingly, a plurality of the turbine blade coupling slots according to the present embodiment may be formed, and the plurality of turbine blade coupling slots may be radially arranged along the circumferential direction of the turbine rotor disk 54.

The turbine vane 440 may be formed in plural, and the plurality of turbine vanes 440 may be formed in a plurality of stages along the axial direction of the rotor 50. Here, the turbine vanes 440 and the turbine blades 420 may be alternately arranged along the air flow direction.

In this embodiment, as shown in FIG. 1, since the turbine blade 420 is configured in four stages, the turbine vane 440 is also configured in four stages, and upstream along the axial direction of the rotor 50 From the side to the downstream, the first-stage turbine vane 444, the second-stage turbine vane 445, the third-stage turbine vane 446 and the fourth-stage turbine vane 447 are placed in the front end (upstream side) of the turbine blades of each stage. It is being deployed. However, the present invention is not limited thereto, and of course, a turbine vane of less than or exceeding 4 stages may be disposed.

In addition, the plurality of turbine vanes 440 may be radially formed along the rotation direction of the rotor 50 for each stage.

Here, the turbine 400, unlike the compressor 200, is in contact with the high-temperature and high-pressure combustion gas, and therefore requires a cooling means to prevent damage such as deterioration.

Accordingly, the gas turbine according to the present embodiment extracts air compressed at some locations of the compressor 200 including an external cooling system to the outside of the casing 100 and supplies it to the turbine 400, In particular, cooling air is not supplied through the rotor 50. This will be described in detail below.

In the gas turbine 1 according to this configuration, the air introduced into the casing 100 is compressed by the compressor 200, and the air compressed by the compressor is mixed with fuel by the combustor 300. The combustion gas is then combusted to become combustion gas, and the combustion gas generated in the combustor is introduced into the turbine 400, and the combustion gas introduced into the turbine 400 passes through the rotor 50 through the turbine blade 420. After being rotated, the rotor 50 is discharged to the atmosphere through the diffuser and rotated by the combustion gas to drive the compressor 200 and the generator. That is, some of the mechanical energy obtained from the turbine may be supplied as energy required to compress air in the compressor, and the rest may be used to generate power by the generator.

Here, the gas turbine is only an embodiment of the present invention, and the external cooling system according to an embodiment of the present invention, which will be described in detail below, can be applied to all general gas turbines.

Hereinafter, an external cooling system according to an embodiment of the present invention applicable to a gas turbine will be described.

The external cooling system of the present invention largely includes a plurality of external cooling passages 500 for supplying air to the turbine 400 by extracting air from different positions of the compressor 200 to the outside of the casing 100, the An outlet cooling channel 600 for extracting air from the outlet of the compressor 200 and supplying it to the turbine 400, and cooling of a pair of the turbine blade 420 and turbine vane 440 located at the same stage at least one It comprises at least one connection cooling flow path 700 that is connected to allow the flow path to communicate.

Hereinafter, it will be described based on cooling the turbine vane 440 and the turbine blade 420 of the fourth stage as described above. However, it is not limited thereto, and of course, it may be applied to cool the turbine vanes and turbine blades of less than or greater than 4 stages.

First, referring to FIG. 2 with respect to the external cooling system according to the first embodiment of the present invention, the outlet cooling passage 600 includes a first-stage turbine vane 444 among the plurality of turbine vanes 440, Air is supplied to the first-stage turbine blade 424 among the plurality of turbine blades 420. That is, the outlet cooling passage 600 is an outlet outer cooling passage 620 for supplying air to the first-stage turbine vane 444 and a first outlet for supplying air to the first-stage turbine blade 424 It includes an inner cooling passage (640).

Specifically, the outlet outer cooling passage 620 extracts compressed air from the outlet of the compressor 200 to the outside of the casing 100 and directly supplies it to the first-stage turbine vane 444, and the first The outlet inner cooling passage 640 extracts compressed air from the outlet of the compressor 200 into the inner side of the casing 100 so that air enters the lower side of the first-stage turbine blade 424, the first-stage turbine It is formed through the lower end of the blade 424.

Accordingly, compressed air at the outlet of the compressor 200 is supplied to the first-stage turbine vane 444 and the first-stage turbine blade 424, thereby cooling the turbine vanes and blades.

At this time, the air supplied through the outlet outer cooling passage 620 is supplied as it is to the first-stage turbine vane 444 without separate heat exchange, but a separate fourth cooler on the first outlet inner cooling passage 640 Since the 840 is disposed, the first-stage turbine blade 424 may be more efficiently cooled by cooling air supplied through the cooling passage 640 inside the first outlet.

In addition, at least one cooling air control valve may be provided on the inlet or flow path of the outlet outer cooling passage 620 and the first outlet inner cooling passage 640, and in this embodiment, the outlet outer cooling passage 620 One cooling air control valve 622 and 642 are installed on the cooling flow path 640 inside the and the first outlet.

Accordingly, the flow rate of the cooling air supplied to the first-stage turbine vane 444 and the first-stage turbine blade 424 can be easily adjusted.

The plurality of external cooling passages 500 may include at least one turbine vane of the plurality of turbine vanes 440 excluding the first-stage turbine vane 444, and the plurality of turbine blades excluding the first-stage turbine blade 424. Air may be supplied from the turbine blade 420 to at least one of the turbine blades at the stage where the connection cooling passage 700 is not formed.

Specifically, in this embodiment, the plurality of external cooling passages 500 are the second-stage turbine vanes 445, the third-stage turbine vanes 446, and the fourth-stage turbine vanes excluding the first-stage turbine vanes 444 ( Air is supplied to the 447), and since the connection cooling passage 700 is formed in the pair of turbine blades and turbine vanes in the second and third stages, as described later, the plurality of external cooling passages 500 Is formed to supply air to the fourth-stage turbine blade 427 in which the connection cooling passage 700 is not formed among the turbine blades excluding the first-stage turbine blade 424.

That is, the plurality of external cooling passages 500 include a first external cooling passage 510 for supplying air to the fourth-stage turbine vane 447 and the fourth-stage turbine blade 427, and the third-stage turbine vane. A second external cooling passage 520 for supplying air to the 446 and a third external cooling passage 530 for supplying air to the second-stage turbine vane 445 may be included.

In this case, the first to third external cooling passages 510, 520, and 530 may be extracted from different positions of the compressor 200, but may be sequentially extracted from a position far from the turbine 400 to a position close to each other.

That is, the compressor 200 may be divided into a front end, a middle end, and a rear end compressor in a distant order from the turbine 400, and the first to third external cooling channels 510, 520 and 530 are respectively front end and stop. And it can be additionally extracted from the downstream compressor.

In addition, in the present embodiment, a cooling passage for supplying air to the fourth-stage turbine vane 447 and the fourth-stage turbine blade 427 is formed to be branched from and supplied from one of the first external cooling passages 510, and However, it is not limited thereto, and may be formed in different flow paths.

As described above, the plurality of external cooling passages 500 and the outlet cooling passages 600 are connected to the inner cooling passages of the turbine blade or turbine vane to supply cooling air, and are formed to communicate with the film cooling holes formed on the surface thereof, The cooling air supplied by the cooling flow path is supplied to the surface of the turbine blade or turbine vane, so that the turbine blade or turbine vane can be cooled by the cooling air.

At this time, the connection cooling passage 700 is provided to cool the turbine blade 420 positioned at the same end through the cooling air supplied to the turbine vane 440, that is, the rear end of the turbine vane 440. It may be formed, and the connection cooling flow path 700 allows the cooling flow path of the turbine blade and the turbine vane located at the same stage to form a single cooling circuit to communicate with each other.

In the present embodiment, the connection cooling passage 700 is formed in each of the second and third stages, the first connection cooling passage connecting the cooling passage of the second-stage turbine vane 445 and the second-stage turbine blade 425 into one 710 and a second connection cooling passage 720 connecting the three-stage turbine vane 446 and the third-stage turbine blade 426 to one cooling passage.

The connection cooling passage 700 may be connected through the lower end of the turbine blade 420 and the turbine vane 440 located at the same end so that air enters the lower side of the turbine blade 420.

Specifically, in the connection cooling passage 700, the cooling air supplied to the turbine vane 440 is flowed to the lower end of the turbine vane 440, and the inside of the space of the U-ring disposed at the lower end of the turbine vane 440 Alternatively, the upper end of the turbine blade 420 through the lower end of the turbine blade 420, that is, the root portion 422 of the turbine blade, which is stored in the space between the turbine rotor disks 54, etc. It can be formed to flow into.

Accordingly, although cooling air is supplied only to the three-stage turbine vane 446 and the second-stage turbine vane 445 through the second external cooling passage 520 and the third external cooling passage 530, respectively, the second It is possible to cool the three-stage turbine blade 426 and the second-stage turbine blade 425 through the connection cooling passage 720 and the first connection cooling passage 710 at a time.

In addition, separate second coolers 820 and third coolers 830 are disposed on the second external cooling passage 520 and the third external cooling passage 530, respectively, so that the air supplied through the cooling passage Cooling can more efficiently cool the turbine blades and turbine vanes.

In addition, since a separate first cooler 810 is disposed on the first external cooling channel 510 as well, it is possible to cool the air supplied through the cooling channel to more efficiently cool the turbine vane and the turbine blade. .

However, the present invention is not limited thereto, and the first cooler may be omitted.

The first to fourth coolers 810, 820, 830, and 840 may cool the air flowing in each cooling channel to different temperatures. That is, it is possible to increase efficiency by cooling the cooling air to an appropriate temperature according to the temperature of the turbine blade 420 or the turbine vane 440 to supply cooling air through each cooling flow path.

In addition, at least one cooling air control valve may be provided on the inlet or flow path of the first to third external cooling channels 510, 520, and 530, and in this embodiment, the first to third external cooling channels ( One cooling air control valve (512, 522, 532) is installed on each of 510, 520, and 530.

Accordingly, it is possible to easily adjust the flow rate of cooling air supplied to the turbine blades and turbine vanes of each stage, and control the supply amount of cooling air by grasping the temperature of each device using a sensor provided inside the power generation device. It is possible.

In addition, the position where air enters the lower side of the first-stage turbine blade 424 among the first outlet inner cooling passage 640 and the second-stage turbine blade 425 and 3 among the connection cooling passages 700. However, a pre-swirler 920 may be provided at a position where air enters the lower side of the turbine blade 426, respectively.

However, the present invention is not limited thereto, and may be provided only in at least one of the positions where air enters the lower side of the first-stage turbine blade 424 to the third-stage turbine blade 426.

FIG. 4 shows an example of a free swirler 920 provided at a position where air enters the lower side of the first-stage turbine blade 424 among the cooling passages 640 inside the first outlet. The position in which the 920 is disposed or the structure of the cooling passage 640 inside the first outlet and other components may be changed according to the type of gas turbine.

As shown in FIG. 5, the free swirler 920 has a shape of a plurality of airfoils or holes, and serves to rotate air drawn in a straight line toward the turbine blade 420. Accordingly, it is possible to increase the cooling effect.

In addition, the position where air enters the lower side of the first-stage turbine blade 424 among the first outlet inner cooling passage 640 and the second-stage turbine blade 425 and 3 among the connection cooling passages 700. However, sealing portions 940 may be provided at positions where air enters the lower side of the turbine blade 426.

However, the present invention is not limited thereto, and may be provided only in at least one of the positions where air enters the lower side of the first-stage turbine blade 424 to the third-stage turbine blade 426.

FIG. 4 shows an example of a sealing part 940 provided at a position where air enters the lower side of the first-stage turbine blade 424 among the cooling flow path 640 inside the first outlet, and the sealing part ( The position at which the 940 is disposed or the structure of the cooling passage 640 inside the first outlet and other components may be changed according to the type of gas turbine.

The sealing part 940 functions to prevent cooling air from flowing through unnecessary flow paths so that cooling flow paths can be formed according to each configuration type of the present invention.

In this case, the sealing part 940 may be formed in various ways if it is for sealing such as a labyrinth seal or a brush seal.

Next, an external cooling system according to a second embodiment of the present invention will be described with reference to FIG. 3. The external cooling system according to the second embodiment of the present invention is partially different from the external cooling system according to the first embodiment, and the rest of the configurations and effects are all the same. The difference from the first embodiment is that the outlet cooling flow path 600 is a first-stage turbine vane 444 among the plurality of turbine vanes 440 and a first-stage turbine blade among the plurality of turbine blades 420 ( Air is supplied to 424 and the second-stage turbine blade 425, and the connection cooling passage 700 is not formed in the second stage, but is formed only in the third stage. Below, it will be described focusing on the above differences.

In the present embodiment, the outlet cooling passage 600 includes a first-stage turbine vane 444 of the plurality of turbine vanes 440, and a first-stage turbine blade 424 and 2 of the plurality of turbine blades 420 However, air is supplied to the turbine blade 425. That is, the outlet cooling passage 600 includes an outlet outer cooling passage 620 for supplying air to the first stage turbine vane 444 and a first stage for supplying air to the first stage turbine blade 424. It includes an outlet inner cooling passage 640 and a second outlet inner cooling passage 660 for supplying air to the second-stage turbine blade 425.

The outlet outer cooling passage 620 and the first outlet inner cooling passage 640 are the same as described in the first embodiment, and as in the present embodiment, the second outlet inner cooling passage 660 is the first outlet The first outlet inner cooling passage 640 and the second outlet inner cooling passage 660 may be branched from and extended from the inner cooling passage 640, but are not limited thereto. It may be formed separately to have different extraction lines. .

At this time, the cooling passage 640 inside the first outlet extracts compressed air from the outlet of the compressor 200 to the inside of the casing 100 so that the air enters the lower side of the first-stage turbine blade 424. Likewise being formed through the lower end of the first-stage turbine blade 424, the second outlet inner cooling passage 660 may also be formed through the lower end of the second-stage turbine blade 425.

Accordingly, compressed air at the outlet of the compressor 200 is supplied to the first-stage turbine vane 444, the first-stage turbine blade 424 and the second-stage turbine blade 425, thereby cooling the turbine vanes and blades. have.

In this embodiment, one cooling air control valve 622, 642, 662 is installed on the outlet outer cooling passage 620, the first outlet inner cooling passage 640, and the second outlet inner cooling passage 660, respectively. Has become.

Accordingly, the flow rate of the cooling air supplied to the first-stage turbine vane 444, the first-stage turbine blade 424, and the second-stage turbine blade 425 can be easily adjusted.

In this embodiment, the plurality of external cooling passages 500 are the same as in the first embodiment, the first external cooling for supplying air to the four-stage turbine vane 447 and the four-stage turbine blade 427 A passage 510, a second external cooling passage 520 for supplying air to the three-stage turbine vane 446, and a third external cooling passage for supplying air to the second-stage turbine vane 445 ( 530) may be included.

In addition, in this embodiment, the connection cooling passage 700 is not formed in the second stage, but is formed only in the third stage. That is, only the second connection cooling passage 720 connecting the three-stage turbine vane 446 and the third-stage turbine blade 426 to one cooling passage is formed, and the second-stage turbine blade 425 is the second outlet Since cooling air is supplied by the inner cooling passage 660, even if the connection cooling passage 700 is formed only in the third stage, cooling air may be supplied to both the turbine blades and the turbine vanes formed in the fourth stage.

In addition, a position where air enters the lower side of the first-stage turbine blade 424 and the second-stage turbine blade 425 among the first outlet inner cooling passage 640 and the second outlet inner cooling passage 660, Pre-swirlers may be provided at positions where air enters the lower side of the third-stage turbine blade 426 of the second connection cooling passage 720.

In addition, a position where air enters the lower side of the first-stage turbine blade 424 and the second-stage turbine blade 425 among the first outlet inner cooling passage 640 and the second outlet inner cooling passage 660, Sealing units may be provided at positions where air enters the lower side of the third-stage turbine blade 426 of the second connection cooling passage 720.

In addition, the present invention, in the gas turbine cooling method including the casing 100, the compressor 200, the combustor 300, and the turbine 400 disposed in the casing, different from the compressor 200 External cooling air supply step of extracting air to the outside of the casing 100 at a location and supplying it to the turbine 400, and outlet cooling of extracting air from the outlet of the compressor 200 and supplying it to the turbine 400 It provides a gas turbine cooling method including the air supply step.

In this case, the air supplied by the external cooling air supply step may cool the turbine blade 420 and the turbine vane 440 pair of the turbine positioned at the same stage at least one.

That is, when described based on the external cooling system according to the first embodiment, the external cooling air supply step may be performed in the second to third stages through the first to third external cooling channels 510, 520, and 530. This is a step of supplying cooling air to the four-stage turbine vanes 445, 446, and 447 and the four-stage turbine blade 427.

In addition, the outlet cooling air supply step is cooled to the first-stage turbine vane 444 and the first-stage turbine blade 424 through the outlet outer cooling passage 620 and the first outlet inner cooling passage 640 This is the step of supplying air.

At this time, the air supplied by the external cooling air supply step is in the second and third stages through the first connecting cooling passage 710 and the second connecting cooling passage 720 respectively formed in the second and third stages. Cool the turbine blade and turbine vane pair together.

That is, the cooling air supplied to the second-stage turbine vane 445 through the third external cooling passage 530 flows to the second-stage turbine blade 425 through the first connection cooling passage 710 and the The second-stage turbine vane 445 and the second-stage turbine blade 425 may be cooled, and the cooling air supplied to the third-stage turbine vane 446 through the second external cooling channel 520 is connected to the second The three-stage turbine blade 426 may be flowed through the cooling passage 720 to cool the three-stage turbine vane 446 and the third-stage turbine blade 426.

In addition, in the supplying of the external cooling air, the inlet or flow path of a plurality of external cooling channels for supplying air to the turbine 400 by extracting air from different positions of the compressor 200 to the outside of the casing 100 It may include a flow rate control step of adjusting the flow rate of the cooling air through at least one cooling air control valve provided on the top.

That is, in the flow rate adjustment step, the flow rate is adjusted through one cooling air control valve 512, 522, 532 respectively installed on the first to third external cooling channels 510, 520, and 530.

Accordingly, it is possible to easily adjust the flow rate of cooling air supplied to the turbine blades and turbine vanes of each stage, and control the supply amount of cooling air by grasping the temperature of each device using a sensor provided inside the power generation device. It is possible.

In addition, the first-stage turbine vane 444 and the first-stage turbine through one cooling air control valve 622, 642 respectively installed on the outlet outer cooling passage 620 and the first outlet inner cooling passage 640 The flow rate of the cooling air supplied to the blade 424 can also be easily adjusted.

According to the gas turbine including the external cooling system of the present invention and a cooling method thereof, a cooling air supply flow path that extracts air from the compressor 200 of the gas turbine and diverts to the outside is formed, and at the same time, the vane As the vane and the blade are cooled by one cooling air flow path, the amount of cooling air used can be reduced, and the cooling air amount per cooling blade/vane of the turbine can be freely adjusted.

In addition, air in a plurality of external cooling passages and an outlet inner cooling passage may be cooled and supplied at different temperatures by using a plurality of coolers.

In addition, it is possible to increase the cooling effect by applying a pre-swirler and sealing structure for each turbine blade end of the turbine.

Ultimately, the design point and partial load performance of the gas turbine can be improved.

The present invention is not limited to the specific embodiments and description described above, and any person with ordinary knowledge in the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims can implement various modifications And, such modifications are within the scope of protection of the present invention.

1: gas turbine 50: rotor
52: compressor rotor disk 53: torque tube
54: turbine rotor disk 55: tie rod
56: fixing nut 100: casing
102: compressor casing 103: combustor casing
104: turbine casing 200: compressor
220: compressor blade 222: compressor blade root portion
240: compressor vane 300: combustor
400: turbine 420: turbine blade
422: turbine blade root portion
424, 425, 426, 427: first to fourth turbine blades
440: turbine vane
444, 445, 446, 447: 1st to 4th stage turbine vanes
500: a plurality of external cooling passages 510: first external cooling passages
520: second external cooling passage 530: third external cooling passage
600: outlet cooling passage 620: outlet outer cooling passage
640: cooling flow path inside the first outlet 660: cooling flow path inside the second outlet
512, 522, 532, 622, 642, 662: cooling air control valve
700: connection cooling flow path 710: first connection cooling flow path
720: second connection cooling channel 810: first cooler
820: second cooler 830: third cooler
840: fourth cooler 920: free swirler
940: sealing part

Claims (18)

Casing;
A compressor disposed in the casing and configured to suck air and compress it at high pressure;
A combustor for mixing and combusting the air compressed by the compressor with fuel; And
Including; a turbine for generating electric power by rotating a plurality of turbine blades using the high temperature and high pressure combustion gas discharged from the combustor,
The turbine includes the plurality of turbine blades, and a plurality of turbine vanes fixed to the casing and alternately disposed with the turbine blades,
A plurality of external cooling passages for supplying air to the turbine by extracting air from different positions of the compressor to the outside of the casing;
An outlet cooling passage for extracting air from the outlet of the compressor and supplying it to the turbine; And
The gas turbine further comprising: at least one connection cooling passage connected to each other so that the cooling passages of the turbine blade and the turbine vane pair are connected to each other.
The method of claim 1,
The outlet cooling passage supplies air to a first-stage turbine vane of the plurality of turbine vanes and a first-stage turbine blade of the plurality of turbine blades,
The plurality of external cooling flow paths include at least one turbine vane of the plurality of turbine vanes excluding the first-stage turbine vane, and a stage in which the connection cooling flow path is not formed in the plurality of turbine blades excluding the first-stage turbine blade. Gas turbine, characterized in that supplying air to at least one turbine blade of the turbine blades.
The method of claim 2,
The outlet cooling flow path,
An outlet outer cooling passage for supplying air to the first-stage turbine vane; And
Containing, a gas turbine, an outlet inner cooling passage for supplying air to the first-stage turbine blade.
The method of claim 2,
The plurality of external cooling flow paths,
A first external cooling passage for supplying air to the four-stage turbine vane and the four-stage turbine blade;
A second external cooling passage for supplying air to the three-stage turbine vane; And
Including; a third external cooling passage for supplying air to the two-stage turbine vane,
The connected cooling flow path, gas turbine, characterized in that formed in each of the turbine blade and turbine vane pair of the second and third stages.
The method of claim 1,
The outlet cooling passage supplies air to a first-stage turbine vane among the plurality of turbine vanes, and to a first-stage and second-stage turbine blade of the plurality of turbine blades,
The plurality of external cooling flow paths include at least one turbine vane of the plurality of turbine vanes excluding the first-stage turbine vane, and the connection cooling flow paths in the plurality of turbine blades excluding the first-stage and second-stage turbine blades. Gas turbine, characterized in that supplying air to at least one of the turbine blades of the not staged.
The method of claim 5,
The outlet cooling flow path,
An outlet outer cooling passage for supplying air to the first-stage turbine vane;
A cooling passage inside the first outlet for supplying air to the first-stage turbine blade; And
Containing, a cooling flow path inside the second outlet for supplying air to the two-stage turbine blade.
The method of claim 5,
The plurality of external cooling flow paths,
A first external cooling passage for supplying air to the four-stage turbine vane and the four-stage turbine blade;
A second external cooling passage for supplying air to the three-stage turbine vane;
Including; a third external cooling passage for supplying air to the two-stage turbine vane,
The connected cooling flow path is a gas turbine, characterized in that formed in the pair of the turbine blade and turbine vane in three stages.
The method according to claim 4 or 7,
The first to third external cooling flow paths are extracted from different positions of the compressor, and are sequentially extracted from a position far from the turbine to a position close to the turbine.
The method according to claim 3 or 6,
A cooling unit for cooling air flowing in at least one of the plurality of external cooling channels and the outlet inner cooling channel;
Gas turbine further comprising a.
The method of claim 9,
The cooling unit, the gas turbine, characterized in that cooling the air flowing in each flow path to different temperatures.
The method according to claim 4 or 7,
A gas turbine, characterized in that at least one cooling air control valve is provided on an inlet or a flow path of the first to third external cooling channels.
The method according to claim 3 or 6,
A gas turbine, characterized in that at least one cooling air control valve is provided on the inlet or flow path of the outlet outer cooling passage and the outlet inner cooling passage.
The method according to claim 3 or 6,
The connection cooling flow path,
The gas turbine, characterized in that connected through the lower end of the turbine blade and the turbine vane located at the same stage so that air enters the lower side of the turbine blade.
The method of claim 13,
The cooling flow path inside the outlet,
Gas turbine, characterized in that formed through the lower end of the turbine blade to allow air to enter the lower side of the turbine blade.
The method of claim 14,
A pre-swirler is provided in at least one of a position where air enters the lower side of the turbine blade of the outlet inner cooling passage and a position of the connection cooling passage where air enters the lower side of the turbine blade. Gas turbine, characterized in that provided.
The method of claim 14,
A sealing part is provided in at least one of a position where air enters the lower side of the turbine blade of the outlet inner cooling passage and a position of the connection cooling passage where air enters the lower side of the turbine blade. Gas turbine.
In the gas turbine cooling method comprising a casing and a compressor, a combustor and a turbine disposed in the casing,
An external cooling air supply step of extracting air from different positions of the compressor to the outside of the casing and supplying it to the turbine; And
Including; an outlet cooling air supply step of extracting air from the outlet of the compressor and supplying it to the turbine,
The air supplied by the external cooling air supply step cools the turbine blade and the turbine vane pair of the turbine positioned at at least one same stage together.
The method of claim 17,
The external cooling air supply step,
The flow rate of cooling air is controlled through at least one cooling air control valve provided on the inlet or at least one of the plurality of external cooling channels for supplying air to the turbine by extracting air from different positions of the compressor to the outside of the casing. A flow rate adjustment step;
Gas turbine cooling method comprising a.

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