JP2851578B2 - Gas turbine blades - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cooling passage for passing a cooling medium in a blade width direction, which is formed in a blade trunk portion of a plurality of rows of moving blades, is connected to the cooling passage, and supplies the cooling medium to the cooling passage. The present invention relates to a gas turbine blade in which a supply-side passage that discharges and a discharge-side passage that discharges a cooling medium that has passed through the cooling passage are formed at a blade root portion of a moving blade.

[0002]

2. Description of the Related Art Recently, in a moving blade used for a gas turbine having a high turbine inlet temperature, a plurality of rows of cooling air passages are provided in the moving blade in a blade width direction, and low-temperature compressed air is flown to form the moving blade. The temperature of the rotor blade itself, which is cooled from the inside and is exposed to high-temperature gas, is kept below the allowable value, which is lower than the blade metal temperature and can maintain the structural strength. like this,
In the air cooling of the moving blade, the cooling air supplied to the moving blade cools the moving blade from the inside when passing through the cooling passage, and at the same time, the leading edge, the blade tip, which tends to become high in temperature due to the structure of the moving blade, Alternatively, the gas is discharged into the high-temperature gas flowing around the outer periphery of the moving blade from a hole provided in the trailing edge portion, and these portions are film- cooled.

FIG. 4 is a longitudinal sectional view of a gas turbine blade in which a moving blade is cooled by cooling air passing through the inside. As shown in the figure, a cooling passage 05 is provided in a blade width direction connecting a blade root portion 02 and a blade tip portion 03 inside a blade trunk portion 04 of a rotor blade 01. This cooling passage 05
Are provided in a plurality of rows in the chord direction which is the front-rear direction of the rotor blade 01, and the blade root 02 is implanted on the outer peripheral surface. Introduced cooling air 06 via the supply side passage 010 provided
Through the blade width direction connecting the blade root 02 and the blade tip 03,
The bucket 01 is convectively cooled from the inside.

[0004] A part of the cooling air 06 flowing from the supply side passage 010, after the blades 01 and convection cooled, blades 0
From the opening 07 or the like which is formed in the first leading edge 011, rotor blades 01
Released at high speed the periphery of into the hot gas 013 flowing wings
The film cooling of the trunk 04 is performed. Also,
Part of the cooling air 06 convectively cooled the wing trailing edge 012
Later, a hole 08 drilled in the trailing edge 012 and a wing tip 03
Released into hot gas 013 through opening 09
Is done. In the figure, reference numeral 014 denotes a turbulator which is disposed in the cooling passage 05 so as to intersect with the flow of the cooling air 06 so as to make the flow of the cooling air 06 turbulent, thereby increasing the cooling efficiency.

As described above, in the conventional gas turbine blade ,
Adopted various cooling structures to enhance cooling, the operating efficiency of the blade 01, the blade thickness is rather thin, structural strength is small, the high temperature strength to prevent high temperature parts partial severe in ing, The structural strength is maintained, and a decrease in the operating efficiency of the rotor blade 01 is prevented.

In recent years, in order to further improve the thermal efficiency of a gas turbine, it has been required to use a higher temperature gas as a working gas than in the past. In addition, it is necessary to enhance the cooling of the rotor blades while making the material rich in material. Thus, since the compressed air is a cooling medium mentioned above can not be obtained sufficiently that cooling effect, large heat capacity, using steam which can increase the cooling efficiency as a cooling medium, has become necessary to cool I have.

[0007] However, in the gas turbine blade that cools the inside of the moving blade 01 by passing steam, the steam used for cooling is cooled by the high-temperature gas 0 like the cooling air 06 described above.
Release into 13 significantly reduces the thermal efficiency of the gas turbine
Because all the steam that was used to cool recovered from the interior of the rotor blade 01, the thermal energy of the recovered water vapor it must be recovered in a steam turbine.

Namely, as in the cooling air 06, if you choose to release the water vapor into the hot gas 013, significantly decrease in temperature of the hot gases 013 due to the release of water vapor, along with the internal efficiency of the turbine is greatly reduced, the dynamic This is because the thermal energy recovered by cooling the blades 01 does not contribute to the improvement of the thermal efficiency of the gas turbine plant, and the improvement of the thermal efficiency of the target gas turbine is hindered.

Accordingly, the point that a supply side passage for supplying steam at a flow rate required for cooling to the cooling passage 05 is provided in the blade root portion 02 is the same as in the case of air cooling described above, but the high temperature strength is severe. It is necessary to supply low-temperature steam as close as possible to the vicinity of the leading edge portion 011 and the trailing edge portion 012 of the rotor blade 01, and the supply-side passage is provided with the leading edge portion 011 and the trailing edge portion 01.
Need to be on both sides. Further, it is necessary to provide a discharge-side passage for discharging steam used for cooling from the cooling passage in the blade root portion 02.

That is, in order to supply low-temperature steam to the cooling passages provided at the leading edge portion 011 and the trailing edge portion 012 of the moving blade 01, the supply side passage is formed by the leading edge portion 011 and the trailing edge portion 012. In order to collect the steam whose temperature has risen by passing through the cooling passage, a discharge-side passage for discharging steam from the cooling passage provided near the center of the moving blade 01 is provided in the vicinity of the blade root portion 02. It is necessary to dispose it between the side passages and provide it on the blade root part 02. For this reason, two systems of supply-side passages having a large flow path area, which increase as the cooling medium is replaced with water vapor from air, and one system of a discharge-side passage arranged between the supply-side passages, each having a small volume. There arises a problem that it is difficult to form the inside of the blade root portion 02.

[0011]

SUMMARY OF THE INVENTION The present invention is provided inside a blade root portion of a moving blade, and is provided at a leading edge or a trailing edge of the moving blade in order to solve the above-mentioned problem caused by improving the thermal efficiency of a gas turbine. After branching off from the supply-side passage configured to supply the cooling medium to one of the provided cooling passages and passing through a passage defined on the side surface of the blade root portion, and not directly communicating with the supply-side passage. The cooling medium can be supplied to the other cooling passage provided at the edge or the leading edge, and a single supply-side passage is provided in the root portion of the blade so that both the leading edge and the trailing edge are provided. It is an object to provide a gas turbine blade that supplies a cooling medium to a cooling passage at the same time.

[0012]

Therefore, the gas turbine blade of the present invention has the following means. A cooling passage provided on the outer peripheral surface below the blade platform provided so as to protrude from the blade root side surface of the moving blade, wherein a passage is provided in the front-rear direction of the moving blade and provided on a leading edge side of the moving blade, or One end of the passage is opened to the supply side passage provided inside the blade root portion, which communicates with one of the cooling passages provided on the trailing edge side and supplies the cooling medium, and is branched from the supply side passage and introduced. A pocket was provided at the other end of the passage, through which an opening for supplying the cooling medium to the cooling passage provided at the trailing edge or the cooling passage provided at the leading edge, which was not directly connected to the supply-side passage, was provided.

[0013] The pocket may be formed as a part of a structure including a blade platform of a rotor blade and a blade plate that is drilled from the side of the blade root below the blade platform. The pockets may be provided only on the side surface of the blade root 1 on the ventral side or the back side of the moving blade, or may be provided on both side surfaces.

According to the gas turbine blade of the present invention, the supply passage is provided only on one of the leading edge and the trailing edge inside the blade root portion having a small volume by the above-mentioned means, and is provided near the leading edge or the trailing edge. A portion of the cooling medium introduced into the supply-side passage can be directly supplied to one of the provided cooling passages, and the remaining cooling medium branches off from the supply passage, passes through the inside of the pocket, and is directly connected to the supply-side passage. It can be supplied to the other cooling passage, which is provided adjacent to the trailing edge which is not in communication or the leading edge.

[0015] Thus, directly from the supply side passage of the blade root portion, or the edge and the trailing edge side before through the pocket, firstly because low-temperature cooling medium is supplied, edge before poor structural strength,
Further, it is possible to prevent the trailing edge from being heated to a higher temperature, use a higher temperature gas as the working gas, and increase the thermal efficiency of the gas turbine.

Further, the cooling medium supplied to the cooling passage can be recovered from the central portion having a relatively low cooling load to the outside of the moving blade after cooling the moving blade from the inside. The working gas is not cooled, and the heat energy accumulated in the cooling medium by the cooling can generate extra power, thereby improving the thermal efficiency of the gas turbine.

In the blade root portion, only one supply-side passage is provided, and the cooling medium is branched to the leading edge side and the trailing edge side by pockets provided on the outer surface of the blade root portion, so that the volume is small. In the blade root portion, the supply-side passage and the discharge-side passage through which steam having a large flow area passes can be installed without difficulty in arrangement, and these passages are restricted due to restrictions on arrangement. It can be formed into a simple structure without having a complicated structure.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas turbine blade according to the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a first embodiment of a gas turbine blade according to the present invention, FIG. 2 is a sectional view taken along the line AA shown in FIG. 1, and FIG. It is a fragmentary sectional view in -B.

As shown in FIG. 1, inside the blade trunk portion 04 of the rotor blade 1, in the blade width direction connecting the blade root 2 and the blade tip 3,
A cooling passage 5 that allows the steam 6 to pass through and cools the bucket 1 from the inside is provided. A turbulator (not shown) is provided in the cooling passage 5 so as to intersect with the flow of the steam 6 so as to make the flow of the steam 6 passing through the cooling passage 5 in a turbulent state to increase the cooling efficiency. It is provided similarly to FIG.

The cooling passages 5 are provided in a plurality of rows in the front-rear chord direction from the leading edge to the trailing edge of the moving blade 1, and the inside of a rotor (not shown) for implanting the blade root 2 on the outer peripheral surface. A part of the low-temperature steam 6 flowing into the supply-side passage 10 provided inside the leading edge 11 of the blade root portion 2 from the steam passage 15 formed in the cooling passage 5 is provided on the leading edge 11 of the cooling passage 5. Through the leading edge side cooling passage 51 in the direction of the blade tip 3, turns at the blade tip 3, flows through the cooling passage 5 provided behind the cooling passage 51 in the direction of the blade root 2, and convection cools the moving blade 1 from the inside. I do. Further, the steam 6 that has reciprocated in the cooling passage 5 between the blade root 2 and the blade tip 3 is perforated into the rotor from the discharge-side passage 16 provided in the blade root 2 and cut off from the supply-side passage 10. The steam flows out to the steam flow path 17.

Further, another portion of the low-temperature steam 6 flowing into the supply-side passage 10 flows through the connection hole 18 opened in the supply-side passage 10 to the trailing edge 12 through a pocket 19 described later. Through the connection hole 20, it flows into the trailing edge side cooling passage 52 provided on the trailing edge side 12 of the cooling passage 5. The low-temperature steam flowing into the trailing edge side cooling passage 52 flows through the trailing edge side cooling passage 52 in the direction of the blade tip 3, turns at the blade tip 3, and passes through the cooling passage 5 provided in front of the cooling passage 54 to the blade root 2. In the direction, and convectively cools the bucket 1 from the inside. Further, the steam 6 that has reciprocated through the cooling passage 5 between the blade root 2 and the blade tip 3 is discharged from the discharge-side passage 16 provided in the blade root 2.
The steam flows into a steam passage 17 that is bored inside the rotor and is isolated from the supply-side passage 10.

Next, as shown in FIG. 2 and FIG. 3, the pocket 19 forms a wing platform 21 and a wing car plate 22 which are provided so as to protrude from the side surface of the wing root portion 2 as a part of components. The space between the lower end of the wing platform 21 and the outer surface of the wing wheel plate 22 is covered with the plate 23, and a passage from the leading edge 11 to the trailing edge 12 is formed inside the wing root 2 side. Things. Front edge side 1 of pocket 19
Reference numeral 1 denotes a supply-side passage 1 which is a connection hole 18 formed in the side surface of the blade root 2.
As described above, the trailing edge side 12 is connected to the trailing edge side cooling passage 52 by the connecting hole 20 formed in the side surface of the blade root 2.

Since the gas turbine blade of the present embodiment is configured as described above, a part of the steam 6 supplied to the supply side passage 10 is introduced into the leading edge side cooling passage 51 and Is a connection hole 18 drilled on the side of the blade root.
A connection hole 20 is provided between the wing platform 21 and the outer periphery of the wing wheel plate 22, and flows in the pocket 19, which is provided in the front-rear direction of the wing, and is formed in the side surface of the wing root 2 on the trailing edge side.
The cooling water enters the trailing edge side cooling passage 52 from below, and the low temperature steam 6 effectively cools the leading edge side 11 and the trailing edge side 12 of the moving blade 1 having a high heat load, thereby preventing a high temperature. Further, the steam that has passed through the leading edge side cooling passage 51 and the trailing edge side cooling passage 52 flows toward the blade center portion 4 while reciprocating in the cooling passage 5 provided in the blade width direction, and is recovered from the recovery side passage 16. You.

As described above, the low-temperature steam 6 is directly supplied from the supply-side passage 10 to the leading-edge cooling passage 52, and the pocket 19 causes the leading-edge side 11 having a higher heat load and the trailing-edge side 12 having a higher heat load to be supplied. At the same time, and then to the central portion where the cooling load is low, so that the cooling efficiency is improved, and the front edge side 11 and the rear edge side 12 which are inferior in structural strength can be heated without impingement cooling structure. Thus, a higher temperature gas can be used for the working gas, and the thermal efficiency of the gas turbine can be increased.

Further, even without employing the film cooling, it is cooled leading edge side 1 1 of the blade 1, it is not possible to cool the high-temperature working gas by steam 6 discharged into the hot gas, also, By cooling, the steam turbine and the like can be driven by the heat energy stored in the steam 6 to generate extra power, and the thermal efficiency of the gas turbine can be improved. Furthermore, wing root 2
Only one supply-side passage 10 need be provided.
The arrangement difficulty of providing the supply-side passage 10 and the discharge-side passage 16 having a large flow passage area in the blade root portion having a small volume is eliminated, and the structure can be simplified.

[0026]

As described above, according to the gas turbine blade of the present invention, the cooling medium used for cooling can be recovered without being released into the high-temperature working gas, by the structure shown in the claims. In addition, cooling steam is first supplied to the higher heat load of the rotor blades and recovered from the lower heat load.
The cooling efficiency becomes very good, and it is possible to prevent the front edge portion and the rear edge portion having low high-temperature strength from becoming hot, and to increase the effect of contributing to the improvement of gas turbine efficiency. Further, there is an advantage that the structure of the blade root can be simplified, the manufacturing cost can be reduced, and the blade can be made highly reliable.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a gas turbine blade of the present invention,

FIG. 2 is a sectional view taken along the line AA shown in FIG.

FIG. 3 is a partial cross-sectional view taken along a line BB shown in FIG.

FIG. 4 is a longitudinal sectional view of a conventional gas turbine blade cooled by cooling air.

[Explanation of symbols]

 1,01 Blade 2,02 Blade root 3,03 Blade tip 4,04 Blade trunk 5,05 Cooling passage 51 Leading edge cooling passage 52 Trailing edge cooling passage 6 Steam 10,010 Supply side passage 11,011 Leading edge 12,012 trailing edge 13,013 hot gas 014 turbulator 15 steam flow path 16 discharge side passage 17 steam flow path 18 connection hole 19 pocket 20 connection hole 21 wing platform 22 wing car plate 23 plate

Claims (1)

(57) [Claims] The cooling blade is connected to a cooling passage formed in a plurality of rows in a blade width direction in a blade trunk portion of a moving blade operating in a high-temperature gas, and connected to the cooling passage in a blade root portion of the moving blade. A supply-side passage that supplies a cooling medium to the passage, and a discharge-side passage that discharges the cooling medium that has passed through the cooling passage are provided, and the moving blades are cooled from the inside with the cooling medium, and the cooled cooling medium is cooled. In a gas turbine blade recovered from the inside of the moving blade, a lower outer surface of a blade platform formed at a blade root portion of the moving blade is provided so as to be partitioned in a front-rear direction, and is provided in front of the moving blade from the supply-side passage. The cooling medium supplied to one of the cooling passages provided on the edge side or the trailing edge side is branched and supplied, and a pocket is provided for supplying the other cooling passage provided on the trailing edge side or the leading edge side of the bucket. Was it A gas turbine blade.