JP3044996B2 - Air-cooled gas turbine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air-cooled gas turbine for cooling a rotor and a rotor blade using a part of compressed air for combustion gas, and more particularly, to recovering cooling air in a combustion chamber to improve turbine efficiency. The present invention relates to a configuration of a cooling air flow path of a closed air-cooled gas turbine intended to improve the cooling efficiency.

[0002]

2. Description of the Related Art In a gas turbine, blades are cooled in order to increase the temperature of a working gas to improve turbine efficiency.
Conventionally, in this type of gas turbine, most of the air used for cooling is discharged from the blades into the working gas. For this reason, the output of the turbine is reduced due to the pressure loss due to the lowering of the working gas due to the low-temperature cooling air dilution, the turbulence between the blades due to mixing, and the pumping power loss of the cooling air. Has a disadvantage that cannot be exhibited. For this reason, recently, as disclosed in Japanese Patent Application Laid-Open No. 58-43575, a gas turbine of a closed air cooling system for recovering cooling air without discharging it into working gas has been proposed. However, no specific recovery method and structure are disclosed.

[0003]

In order to realize a gas turbine of a closed air cooling system efficiently according to the purpose, not only recovery of cooling air from a stationary blade having a relatively easy configuration but also cooling of cooling air is performed. In order to reduce the pumping power, it is necessary to recover the cooling air of the rotor blade. for that purpose,
The discharge port for the cooling air to the outside of the rotor is arranged as close as possible to the center of rotation, and the temperature rise of the rotor member due to the high-temperature air after cooling the moving blades is reduced, and the generation of thermal stress and deformation of the rotor A major issue is how to reduce the unbalanced vibration and the like. These greatly depend on the configuration of the cooling air supply path and the recovery path in the rotor, and it is necessary to make the structure as simple as possible in consideration of the high speed rotating body.

An object of the present invention is to provide a gas turbine of a closed air cooling system suitable for improving efficiency by overcoming the problems described above.

[0005]

SUMMARY OF THE INVENTION An air-cooled gas of the present invention
The turbine transfers some of the air flowing to the combustor inside the rotor.
After cooling to the rotor and the rotor blades.
Air-cooled gas turbine that collects
Part of the air pressurized by the compressor is
From inside the rotor, and through the inside of the rotor,
A supply path for supplying air to the wings,
The air that flows through the rotor blades is collected in the combustion chamber through the rotor.
It is characterized by having a collection route.

Alternatively, the air-cooled gas turbine of the present invention
Is to move a part of the air flowing to the combustor through the rotor
And cooling air after cooling the rotor and the rotor blades.
An air-cooled gas turbine to be recovered, which is lifted by a compressor.
The pressurized air is supplied from the rotor end into the rotor,
Supply path for supplying air to the rotor blade via the inside of the rotor
And the air formed on the axial side of the combustor and flowing through the rotor blades
The air passes through the interior of the rotor and
And a recovery path for guiding the fuel to the combustion chamber.
Features.

Alternatively, the air-cooled gas turbine of the present invention
Is to move a part of the air flowing to the combustor through the rotor
And cooling air after cooling the rotor and the rotor blades.
An air-cooled gas turbine to be recovered, which is lifted by a compressor.
Pressure increasing means for increasing the pressure of the compressed air;
Supply the pressurized air into the rotor from the rotor end
And a supply path for supplying air to the rotor blade through the inside of the rotor.
Air flowing through the rotor blades and the inside of the rotor,
Between the rotor and the combustor located on the rotor outer peripheral side
Collected in the gap, and the collected air is guided to the combustor.
And a collecting path.

Alternatively, the cooling medium recovery type gas turbine of the present invention
The bins supply cooling media through the interior of the rotor to the rotor blades.
Supply path of the cooling medium, and after cooling the rotor and the rotor blades.
Cooling medium recovery through which the cooling medium passes through the inside of the rotor
A cooling medium recovery gas turbine comprising:
In the cooling medium supply path formed in the rotor,
The cooling medium supplied to the rotor blades flows into the
The recovery path through which the cooling medium flows after flowing through the rotor blades is formed.
It is characterized by arranging piping to be formed.

The air-cooled gas turbine according to the present invention has a combustion
A part of the air flowing to the vessel is supplied to the rotor blade through the rotor.
After cooling the rotor and the rotor blades, recover the cooling air.
Air-cooled gas turbine,
Part of the air that has flowed from the downstream side of the gas turbine
And the rotor blades are installed through the inside of the rotor.
One side of the disc and a member adjacent to the side
A supply path for supplying air to the bucket through a path formed
And air flowing through the bucket from the supply path.
Formed including the other side of the disk and members adjacent to the side
Through the rotor, collect through the rotor, and
Characterized by having a recovery path through which the exhausted air is led to the combustion chamber
And

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

The cooling air supply path and recovery in the rotor described above.
By forming a path , the center cavity of the rotor is filled with low-temperature air, and the center of the disk, which generates large stress due to strong centrifugal force, is uniformly cooled, and the generation and deformation of thermal stress Few.

On the other hand, a part of the outer peripheral side wall of the disk and the spacer are heated by the high-temperature air after the cooling of the moving blades. In addition to being cooled by the low-temperature air flowing through the supply path, the temperature rise is reduced by half. In addition, since the centrifugal stress of the outer peripheral portion is smaller than that of the central portion, the restriction on the thermal stress is relaxed, and the influence of heating is reduced. In particular, when the disk is recovered from the spacer internal flow path through the disk through flow path, the disk is not heated from the side, and only the through flow path serves as a heat source, and is blocked by the through flow path and the internal flow path of the spacer. By mounting a heat tube or applying a heat-shielding coating, heat transfer from the high-temperature air to the disk or spacer is cut off, and the rise in temperature of the entire rotor can be greatly reduced.

In the case where the stacking bolt holes are used as the disk through-flow passages, there is an advantage that the recovery path can be configured more easily and the reduction in the strength of the disk due to the formation of the through-flow passage can be reduced.

However, the pumping power of the cooling air is proportional to the square of the rotational radius position of the cooling air outlet. In the present invention, the cooling air is discharged from the rotor blades in order to discharge the cooling air from the side of the rotor. Outflow turning radius is about 2
The pumping power can be reduced to about a quarter.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a cross section of a closed air-cooled gas turbine according to an embodiment of the present invention, and shows a case where the gas turbine is applied to a two-stage turbine for easy understanding.

The rotor 10 has a shaft 11, a shaft 12, a disk 1
3, constituted by a disk 14 and a spacer 15,
They are fastened together by stacking bolts 16. On the outer periphery of each of the disks 13 and 14, moving blades 21 and 22 having cooling passages 21b and 22b formed therein are implanted through dovetails 21a and 22a.

A wide area cavity 17 including disk center holes 13a and 14a and a space between disks is formed in the center of the rotor, and a plurality of slits 13b are formed from the cavity 17 on the side of the disk at a stacking radius position. And 14b, and the cooling flow path 2 in the rotor blade through the cavities 23 and 24 formed between the shaft end and the disk.
A cooling air supply path leading to 1b and 22b is formed.

On the other hand, the outlets of the blade cooling passages 21b and 22b are open to the cavities 19 and 20 formed between the outer peripheral side wall of the disk and the spacer, and the holes 15b, the grooves 15a formed in the spacer and the disk are opened. Through the penetrated through flow path 18, a recovery path that opens to the wheel space 51 between the rotor 10 and the combustion chamber 50 is configured.

Then, after being bleed from the compressor and boost-compressed, it flows into the rotor 10 through the center hole of the shaft 12, and the cooling air flows from the cavity 17 at the center of the rotor to the slit 13b and the slit 13b as indicated by an arrow 25. 14b, the cooling passages 21b in the moving blades 21 and 22
And 22b to cool the respective wings.

Among the air heated by cooling the blades, the moving blade 2
1 flows into the cavity 19 through the groove 15a and the disk penetrating flow path 18, and from the rotor blade 22 to the cavity 20.
Is discharged into the wheel space 51 through the groove 15b, the cavity 19 and the disk through channel 18, and is recovered into the combustion chamber 50 from the communication hole 50a.

In the process of supplying and recovering the cooling air described above, since the center cavity 17 of the rotor is filled with low-temperature air, the center of the disk smaller in diameter than the stacking position is uniformly cooled, The temperature is kept as low as the cooling air. On the other hand, the wall surfaces on the cavities 19 and 20 side of the disk outer peripheral portion and the periphery of the through flow path 18 are heated by the high-temperature air after the blade cooling, but the wall surfaces and dovetails forming the opposite cavities 23 and 24 are formed. Since the outer peripheral wall is cooled by low-temperature cooling air, the temperature rise of the disk is reduced by half. Therefore, it is possible to recover the cooling air with a simple structure without requiring a special transportation pipe. In addition, so-called pumping power is required as the swirling speed increases in the process of cooling air flowing from the center of the rotor to the outer peripheral side, but this power is absorbed as rotational force in the process of flowing from the rotor blade to the center side. . Since the power is proportional to the square of the radius of rotation, the cooling air is discharged to the outside of the rotor from almost half the radius of the rotor.
Three thirds are recovered.

FIG. 2 shows another embodiment according to the present invention. In this case, a new disc through hole leading from the cavity on the outer peripheral portion of the rotor to the wheel space was not newly formed, and the stacking bolt hole was also used. That is, the high-temperature cooling air introduced into the cavities 19 and 20 after cooling the rotor blades inserts the groove 15c formed in the spacer 15 and the stacking bolt 27 already provided in the disk 13 as shown by the arrow 26. It flows out into the wheel space 51 through the bolt hole 28 to be collected, and is collected in the combustion chamber 50. However, since the predetermined cooling air cannot flow only through the gap between the bolt and the hole, as shown in FIG.
The cross section of the flow path is expanded by removing a part of the stacking bolt 27. In this case, the stacking bolts are heated by directly exposing the high temperature to the high-temperature air, which limits the heat load of the blades, that is, the working gas temperature of the turbine. However, the recovery path can be configured more simply, and the disk is not perforated. There is an advantage that the strength can be kept high by the amount.

FIG. 4 shows an embodiment in which the supply and recovery paths of the cooling air are changed to enhance the cooling of the spacer. That is, the cooling air to the first stage blade 31 implanted on the outer periphery of the disk 30 is supplied through the plurality of slits 32a formed in the spacer 32 and the cavity 33 between the disk and the spacer, and the same as in the above-described embodiment. Conversely, the cavity 33 is a component of the supply path. The cooling air flowing out of the first stage rotor blades is discharged through a cavity 35 between the disk 30 and the shaft 37 to a wheel space 51 from a hole 37 a formed in the shaft end, and is collected in the combustion chamber 50. The air flowing out of the two-stage blade 22 to the cavity 34 passes through the cavity 33 which is a supply path, passes through the recovery pipe 36 passed between the spacer 32 and the disk 30, and is cooled from the first stage blade in the cavity 35. Merges with air and is collected.

In the case of this embodiment, the recovery radius of the pumping power slightly decreases because the rotational radius position of the recovery air outlet changes to a position slightly larger than that of the previous embodiment, but the recovery path is simpler. In addition, since one surface of the spacer is cooled by low-temperature air, there is an advantage that stress generated due to a difference in thermal expansion between the spacer and the disk can be reduced.

FIG. 5 shows still another embodiment. In this embodiment, recovery chambers 44 and 45 are formed around the outer periphery of the spacer 40 at the outlet of the bucket cooling passage. In the radial direction of the spacer, there are formed a plurality of internal flow paths 40a in which a heat shield tube 46 is inscribed. It communicates with the wheel space 51 through a recovery pipe 47 supported and mounted on the shaft 43 and the shaft 43. Further, a plurality of slit flow paths 40b and 40c are formed on both sides of the spacer in the same phase as the internal flow path 40a, and the slits allow the cavity 17 at the center of the rotor and the cavities 48 and 49 on the outer peripheral side to communicate with each other. I have. On the other hand, slit channels 41a and 42a are formed on the side surfaces of the disks 41 and 42 as in the embodiment of FIG.
Holes 41b and 42b communicating with the cavities 48 and 49 and the cooling air supply port at the root of the rotor blade are formed in the outer peripheral portion.

FIG. 6 shows the cross-sectional shape of the heat shield tube 46 and the recovery tube 47. Ribs project from the outer wall of the tube in order to reduce the contact area with the spacer and the disk.

Therefore, a part of the air introduced into the cavity 17 at the center of the rotor is supplied to the rotor blade 21 through two paths, a path passing through the slit 41a and a path passing through the slit 40b and the hole 41b, and the remaining air is supplied. Is the path through the slit 42a and the path through the slit 40c and the hole 42b.
It is supplied to the bucket 22 from the path. Therefore, the disk and the center of the spacer are cooled from both sides by the low-temperature cooling air.

On the other hand, the high-temperature air after cooling the rotor blades is discharged from the recovery chambers 44 and 45 on the outer periphery of the spacer to the wheel space 51 through the spacer internal flow path 40a and the recovery pipe 47, and is recovered in the combustion chamber 50. . At this time, the recovery path is heated by the high-temperature cooling air, but is insulated by the heat shield pipe 46 and the recovery pipe 47 except for the outer periphery of the spacer, and since the periphery is cooled by the low-temperature cooling air, The temperature rise is very small. Even at the outer peripheral portion of the spacer, the rear surface of the wall forming the collection chambers 44 and 45 is cooled by low-temperature air, so that the temperature rise is reduced by half.

In this embodiment, a heat shield tube having ribs projecting from the outer wall is used as the heat shield means.
Even if a thermal barrier coating is applied to the inner wall of Oa, substantially the same heat insulating effect can be obtained.

From the viewpoint of pumping power recovery, in the present embodiment, the rotational radius of the cooling air discharge port can be reduced to about the outer diameter of the shaft 43, so that most of the pumping power can be recovered.

[0036]

According to the present invention, it is possible to meet the purpose of improving efficiency.
To provide a suitable closed air-cooled gas turbine
can do. In other words, high-temperature air after cooling the rotor blades can be collected in the combustion chamber without raising the temperature of the rotor, and most of the pumping power of the cooling air can be collected. Thus, a suitable air-cooled gas turbine with low temperature reduction due to mixing of cooling air into the air and loss due to turbulence in the flow can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a cooling passage inside a rotor according to the present invention.

FIG. 2 is a view showing another embodiment of the cooling passage inside the rotor according to the present invention.

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is a view showing another embodiment of the cooling flow path in the rotor according to the present invention.

FIG. 5 is a view showing another embodiment of the cooling passage in the rotor according to the present invention.

FIG. 6 is a sectional view of a heat shield tube and a recovery tube.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Rotor, 13, 14 ... Disk, 15 ... Spacer, 17 ... Center cavity, 18 ... Disk penetration flow path, 19, 20 ... Outer peripheral cavity, 21, 22 ... Blade, 27 ... Stacking bolt, 28 ... Stacking Bolt hole, 36 ... Recovery pipe, 40a ... Spacer internal flow path, 4
4, 45 ... collection room, 46 ... heat shield tube, 47 ... collection tube, 50
... combustion chamber, 51 ... wheel space.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masami Noda 502 Kandamachi, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. Hitachi, Ltd. Hitachi factory (72) Inventor Hatsuru Toriya 3-1-1, Sakaimachi, Hitachi, Ibaraki Pref. Hitachi, Ltd. Hitachi factory (56) References JP-A-5-86901 (JP, A) JP-A Sho 57-140502 (JP, A) JP-A-2-75731 (JP, A) JP-A-62-193143 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02C 7/18

Claims (7)

(57) [Claims] 1. A part of air flowing to the combustor is supplied to the rotor blade via the inner rotor, an air-cooled gas turbine for recovering cooling air after cooling the rotor and blades, by the compressor A part of the pressurized air is supplied to the inside of the rotor from the downstream side of the gas turbine, and a supply path for supplying air to the moving blade via the inside of the rotor, and an air flowing through the moving blade from the supply path. An air-cooled gas turbine comprising a recovery path for recovering the gas into a combustion chamber through a rotor. 2. An air-cooled gas turbine for supplying a part of air flowing to a combustor to a moving blade through the inside of a rotor and recovering cooling air after cooling the rotor and the moving blade. A supply path for supplying the pressurized air to the inside of the rotor from the end of the rotor and supplying the air to the moving blade through the inside of the rotor, and a flow path formed axially from the combustor and flowing through the moving blade. An air-cooled gas turbine, comprising: a recovery path that guides the interior of the rotor to a high-pressure wheel space of the rotor and recovers the combustion chamber. 3. An air-cooled gas turbine for supplying a part of air flowing to a combustor to a rotor blade through an inside of a rotor, and recovering cooling air after cooling the rotor and the rotor blade, wherein the compressor uses a compressor. Pressurizing means for pressurizing the pressurized air, a supply path for supplying the air pressurized by the pressurizing means from the rotor end to the inside of the rotor, and supplying air to the moving blade via the inside of the rotor; And a recovery path through which the air flowing through the rotor is collected in a gap formed between the rotor and a combustor located on the outer peripheral side of the rotor through the interior of the rotor, and the collected air is guided to the combustor. Features an air-cooled gas turbine. 4. A cooling medium supply path for supplying a cooling medium to the rotor blades through the interior of the rotor, a cooling medium recovery path for recovering the cooling medium after cooling the rotor and the rotor blades through the rotor interior, and A cooling medium recovery type gas turbine having a cooling medium supplied to the moving blades around the cooling medium supply path formed in a rotor, and flowing through the moving blades inside itself. A cooling medium recovery type gas turbine, wherein a pipe forming a recovery path through which the cooling medium flows after the cooling is disposed. 5. The air-cooled gas turbine according to claim 1, wherein the rotor is fixed to a plurality of stacked disks and a penetrating portion provided on the disks. An air-cooled gas turbine, comprising: a stacking bolt; wherein the air flowing through the wing flows through a through portion where the stacking bolt is arranged and is collected. 6. The air-cooled gas turbine according to claim 1, further comprising a pipe in a recovery path of the air flowing through the wings, in which the recovery air flows inside itself and a rib is provided on the outer periphery. Features an air-cooled gas turbine. 7. An air-cooled gas turbine for supplying a part of air flowing to a combustor to a rotor blade through an interior of a rotor, and recovering cooling air after cooling the rotor and the rotor blade, wherein the compressor uses a compressor. A part of the pressurized air is supplied to the inside of the rotor from the downstream side of the gas turbine, and is formed through the inside of the rotor, including one side surface of the disk on which the rotor blade is installed and a member adjacent to the side surface. A supply path for supplying air to the moving blade through a path that passes through the path, and a path formed including the other side of the disk and a member adjacent to the side surface of the air flowing from the supply path to the moving blade, An air-cooled gas turbine, comprising: a recovery path that is recovered through a rotor and the recovered air is guided to a combustion chamber.