JPH06330764A - Flow path incorporating structure of gas turbine - Google Patents

Abstract

PURPOSE:To provide a low temperature compressor diffuser in a back-to-back type gas turbine. CONSTITUTION:In a gas turbine having a compressor impeller 2 and turbine rotor 4 provided close back to back, a heat insulating ring 30 is interposed between a compressor diffuser 7 and turbine nozzle 21. Diffuser fastening bolts 36 for fastening members 14, 15 defining the compressor diffuser 7 relative to the heat insulating ring 3 and nozzle fastening bolts 37 for fastening a member 20 defining the turbine nozzle 21 relative to the heat insulating ring 30 are provided respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for assembling a flow path of a diffuser of a compressor and a turbine nozzle which are close to each other in a gas turbine.

[0002]

2. Description of the Related Art As a conventional gas turbine, for example, FIG.
There is a back-to-back type as shown in (Reference material: Kawasaki Heavy Industries Technical Report No. 92, issued by Kawasaki Heavy Industries, Ltd. in April 1986).

To explain this, the compressor 1
The impeller 2 and the rotor 4 of the turbine 3 are provided back to back, and their rotating shafts 9 are cantilevered via rolling bearings 5.

The compressor impeller 2 is housed in the compressor housing 6, and the turbine rotor 4 is housed in the turbine housing 20.

The intake air sucked by the compressor impeller 2 as shown by the arrow in the figure is accelerated by the compressor impeller 2 and then is depressurized while passing through the compressor diffuser 7 and is sent to a combustor (not shown). . The gas heated to about 800 to 900 ° C. in the combustor is introduced into the turbine rotor 4 through the turbine nozzle 21 as shown by the arrow in the figure.

The compressor diffuser 7 is defined between a diffuser front plate 14 and a diffuser back plate 15.
The turbine nozzle 21 is defined by a nozzle front plate portion 23 and a nozzle back plate portion 24 which are integrally formed with the turbine housing 20. Diffuser back plate 15 and nozzle back plate 24
Are joined to each other, and both are fastened to each other via a plurality of bolts 8.

[0007]

However, in such a conventional flow path assembling structure of a gas turbine, the diffuser back plate 15 and the nozzle back plate portion 24 are joined together and fastened. Therefore, there is a problem in that the heat of the turbine nozzle 21 through which the high-temperature gas passes during operation is directly transmitted to the compressor diffuser 7, and the compressor diffuser 7 becomes high in temperature to lower the efficiency of the compressor 1.

Further, in order to secure heat resistance, the compressor diffuser 7 cannot use a lightweight aluminum material, and must use stainless steel or the like.
The weight increase was inevitable.

In view of the above problems, the present invention aims to reduce the temperature of a compressor diffuser in a back-to-back type gas turbine.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a compressor impeller and a turbine rotor are provided back to back in close proximity to each other, and a compressor diffuser for boosting intake air discharged from the outer peripheral portion of the compressor impeller is provided. In a gas turbine in which a turbine nozzle that guides high-temperature gas discharged from a combustor is provided in a portion, a heat insulating ring that is interposed between the compressor diffuser and the turbine nozzle is provided, and a member that defines the compressor diffuser with respect to the heat insulating ring And a nozzle fastening bolt for fastening a member defining the turbine nozzle to the heat insulating ring.

[0011]

The member defining the compressor diffuser and the member defining the turbine nozzle are fastened in a non-contact state via the adiabatic ring, so that heat transfer from the turbine nozzle to the compressor diffuser is performed via these members. It can be suppressed.

A diffuser fastening bolt and a nozzle fastening bolt are provided respectively, and an insulating ring is also interposed between the bolts, so that the amount of heat conducted from the turbine nozzle to the compressor diffuser via each bolt is greatly suppressed. You can On the other hand, in the case of the structure including the bolts penetrating the members that respectively define the turbine nozzle and the diffuser, even if a heat insulating material is interposed between the members, it is transmitted from the turbine nozzle to the diffuser through the bolts. The amount of heat is large and a sufficient heat insulating effect cannot be obtained.

By thus preventing the heat of the high temperature gas flowing through the turbine nozzle from being transferred to the intake air flowing through the compressor diffuser, the temperature rise of the compressed air flowing out from the compressor diffuser can be suppressed and a high compressor efficiency can be obtained. . Further, since the temperature rise of the member defining the compressor diffuser is suppressed, it is possible to reduce the temperature by forming the compressor diffuser with an aluminum-based metal.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, a back-to-back type gas turbine includes an impeller 2 of a compressor 1,
The rotors 4 of the turbine 3 are provided so as to be connected back to back. Rotor shaft 9 integrally formed with turbine rotor 4
Is supported in a cantilever manner via a rolling bearing 5. A distance collar 13 fitted with an oil seal 12 is interposed between the rotary shaft 9 and the bearing housing 11.

The intake air sucked by the compressor impeller 2 as shown by the arrow in the figure is accelerated by the rotation of the compressor impeller 2, and then the compressor diffuser 7
The pressure is increased while decelerating in the process of passing through, and is sent to a combustor (not shown) through a flow path defined between the engine housing 29 and the tubular member 28.

The compressor impeller 2 is housed in a compressor housing 6. A compressor diffuser 7 is defined between the diffuser front plate 14 and the diffuser back plate 15 provided on the outer peripheral portion of the compressor housing 6.

One end of the engine housing 29 is joined to the outer peripheral portion of the diffuser front plate 14, and both of them are provided with a plurality of bolts 2.
It is fastened via 6.

As shown in FIG. 2, a plurality of diffuser vanes 16 for guiding intake air are integrally formed on the diffuser back plate 15 in the compressor diffuser 7 at regular intervals.

The inner peripheral edge of the diffuser front plate 14 is joined to the annular step 10 of the compressor housing 6 for positioning. The diffuser front plate 14 and the compressor housing 6 are fastened via a plurality of bolts 25. A pin (not shown) is fitted between the diffuser front plate 14 and the diffuser back plate 15 to perform positioning in the rotational direction.

The bearing housing 11 includes a plurality of support columns 17
Are formed so as to project in a direction parallel to the rotating shaft 9. In the front plate 14 of the diffuser, the stepped portion 18 is the flange portion 1 of the column portion 17.
Positioning is performed by joining to 9.

The hot gas sent from the combustor is introduced into the turbine rotor 4 through the turbine nozzle 21 from the flow passage defined by the tubular members 28 and 27 as shown by the arrow in the figure.

The turbine nozzle 21 is defined by a nozzle front plate portion 23 and a nozzle back plate portion 24 which are integrally formed with the turbine housing 20. As shown in FIG. 3, the turbine nozzle 21 has a plurality of nozzle vanes 22 integrally formed with the turbine housing 20 at regular intervals.

Diffuser back plate 15 and nozzle back plate 24
An adiabatic ring 30 is interposed between them. The heat insulating ring 30 is formed of a heat insulating material having a relatively low thermal conductivity such as zirconia.

The heat insulating ring 30 has an outer ring portion 31, an inner ring portion 32 and a disk portion 33, and has an H-shaped cross section. The outer ring portion 31, the inner ring portion 32, and the disc portion 33 are each formed in an annular shape concentric with the rotating shaft 9.

Diffuser back plate 15 and nozzle back plate 24
Are joined to the outer ring portion 31 and the inner ring portion 32 of the heat insulating ring 30, respectively, so that positioning of the both in a direction parallel to the rotation axis 9 is performed.

The thicknesses of the outer ring portion 31 and the inner ring portion 32 of the heat insulating ring 30 are set to the minimum in order to secure their strength, and the contact areas of the diffuser back plate 15 and the nozzle back plate part 24 are suppressed. .

Diffuser back plate 15 and nozzle back plate portion 24
At the end, annular step portions 34 and 35 are formed to be joined to both ends of the outer ring portion 31 of the heat insulating ring 30, respectively, and the rotary shaft 9 of both is positioned in the radial direction.

The diffuser front plate 14 with respect to the heat insulating ring 30
A diffuser fastening bolt 36 for fastening the diffuser back plate 15 and the flange portion 19 of the column portion 17 is provided, and a nozzle fastening bolt 37 for fastening the turbine housing 20 to the heat insulating ring 30 is also provided.

As shown in FIG. 5, four diffuser fastening bolts 36 and four nozzle fastening bolts 37 are provided, and holes 38 and 39 are formed in the heat insulating ring 30 at predetermined intervals. It The diffuser fastening bolt 36 penetrates a hole 52 formed in the diffuser vane 16. The nozzle fastening bolt 37 penetrates the hole 53 formed in the nozzle vane 22.

As shown in FIG. 4, the diffuser fastening bolt 36 has a quadrangular head portion 41, and the head portion 41 abuts the outer ring portion 31 or the inner ring portion 32 of the heat insulating ring 30 to diffuse the diffuser. The fastening bolt 36 is prevented from rotating. The cap nut 4 is attached to the bolt 36 for fastening the diffuser.
5 is screwed.

Head 41 of the diffuser fastening bolt 36
A gap 46 is defined between the turbine housing 20 and the turbine housing 20.

The diffuser fastening bolt 36 has an annular spigot portion 42, while the heat insulating ring 30 has a hole 43 into which the spigot portion 42 is fitted. Inlay part 42
The diffuser fastening bolts 36 are positioned by fitting the holes 43 into the holes 43, and the diffuser fastening bolts 36, the diffuser front plate 14, the diffuser back plate 15, and the holes formed in the flange portion 19 of the column portion 17 are An annular gap 44 is defined therebetween.

The diffuser back plate 15 has an annular step portion 34.
Is joined to the outer ring portion 31 of the heat insulating ring 30, and a pin (not shown) is fitted between the diffuser front plate 14 and the diffuser back plate 15 for positioning. Therefore, the diffuser front plate 14 and the diffuser back plate 15 are not positioned in the radial direction of the rotary shaft 9 by the diffuser fastening bolts 36.

The nozzle fastening bolt 37 is screwed into a screw hole 47 formed in the turbine housing 20. Adiabatic ring 3
A hole 49 for seating the hexagonal head 48 of the nozzle fastening bolt 37 is formed at 0, and a gap 50 is defined between the head 48 and the diffuser back plate 15.

A disc-shaped heat insulator 40 is interposed between the compressor impeller 2 and the turbine rotor 4. The outer peripheral end of the heat insulator 40 is supported by being fitted into the diffuser back plate 15.

With the above construction, the operation will be described.

Nozzle back plate 2 of turbine housing 20
4 and the diffuser back plate 15 are supported in a non-contact state with each other via a heat insulating ring 30, and a diffuser fastening bolt 36 and a nozzle fastening bolt 37 are provided via the heat insulating ring 30, respectively. The amount of heat conducted to the compressor diffuser 7 can be greatly suppressed.

As one of heat transfer paths from the turbine nozzle 21 to the compressor diffuser 7, the nozzle back plate portion 24 of the turbine housing 20 to the outer ring portion 3 of the heat insulating ring 30.
There is a route to reach the diffuser back plate 15 via 1 and the inner ring portion 32. The outer ring portion 31 and the inner ring portion 32 of the heat insulating ring 30.
Has a minimum thickness to ensure its strength,
Since the contact area between the diffuser back plate 15 and the nozzle back plate portion 24 is minimized, it is possible to prevent the compressor diffuser 7 from being heated in this heat transfer path.

As one of heat transfer paths from the turbine nozzle 21 to the compressor diffuser 7, the nozzle back plate portion 24 of the turbine housing 20 to the outer ring portion 3 of the heat insulating ring 30.
There is a route to reach the diffuser front plate 14 through the disc 1, the disc portion 33, and the diffuser fastening bolt 36. The diffuser fastening bolt 36 defines a gap 46 between the turbine housing 20 and an annular gap between the diffuser front plate 14, the diffuser back plate 15, and the holes formed in the flange portion 19 of the column portion 17. By defining 44, the heat transfer path formed via the diffuser fastening bolts 36 is lengthened, so that the compressor diffuser 7 is prevented from being heated by this heat transfer path.

As one of the heat transfer paths from the turbine nozzle 21 to the compressor diffuser 7, the nozzle fastening plate 3 from the nozzle back plate portion 24 of the turbine housing 20.
7 and the disk portion 33 of the heat insulating ring 30 and the outer ring portion 31 to reach the diffuser front plate 14. The diffuser fastening bolts 36 define a gap 46 between the turbine housing 20, and the diffuser front plate 14, the diffuser back plate 15, and the flange portion 1 of the column portion 17.
Since the annular gap 44 is defined between the holes formed in 9 to lengthen the heat transfer path formed through the diffuser fastening bolts 36, the compressor diffuser 7 is connected by this heat transfer path. Can be suppressed from being heated.

Thus, it is possible to sufficiently prevent the heat of the high temperature gas flowing through the turbine nozzle 21 from being transferred from each heat transfer path to the intake air flowing through the compressor diffuser 7.
As a result, the temperature rise of the compressed air flowing out from the compressor diffuser 7 is suppressed, and high compressor efficiency is obtained.

Further, by suppressing the temperature rise of the diffuser front plate 14 and the diffuser back plate 15 which define the compressor diffuser 7, it is possible to secure sufficient heat resistance even if they are formed of aluminum-based metal. Next to
The weight of the gas turbine can be reduced.

On the other hand, in the case of the conventional apparatus having the bolts penetrating the respective members defining the turbine nozzle and the diffuser, even if the heat insulating material is interposed between them,
The amount of heat transferred from the turbine nozzle to the diffuser through the bolt is large, and a sufficient heat insulation effect cannot be obtained.

Since the nozzle fastening bolts 37 and the diffuser fastening bolts 36 are independently provided, the degree of freedom in designing the bolt diameter of the nozzle fastening bolts 37 is increased, and the number of bolts can be reduced.

Next, in the other embodiment shown in FIG. 6, annular step portions 55 and 56 which are joined to each other are integrally formed on the diffuser back plate 15 and the nozzle back plate portion 24, and the rotary shaft 9 of both of them.
Is positioned in the radial direction and has a sealing function. The parts corresponding to those in FIG. 1 are designated by the same reference numerals.

A disk-shaped heat insulator 40 is interposed between the compressor impeller 2 and the turbine rotor 4, and the heat insulator 40 has its outer peripheral end portion fitted to the annular step portion 56 of the nozzle back plate portion 24. It is supported.

In this case, since the contact area of the adiabatic ring 30 with the diffuser back plate 15 and the nozzle back plate portion 24 is further reduced, the compressor diffuser 7 is provided in the heat transfer path formed by the outer ring portion 31 of the adiabatic ring 30. It is possible to suppress heating.

Further, the heat insulating ring 30 is the diffuser back plate 15
Also, since the nozzle back plate portion 24 is not positioned in the radial direction, the required processing accuracy can be greatly reduced and the productivity can be improved.

[0050]

As described above, according to the present invention, the compressor impeller and the turbine rotor are provided back to back in close proximity to each other, and the compressor diffuser for boosting the intake air discharged from the outer peripheral portion of the compressor impeller is provided. In a gas turbine in which a turbine nozzle that guides high-temperature gas discharged from a combustor is provided on an outer peripheral portion, an adiabatic ring is provided between the compressor diffuser and the turbine nozzle, and a compressor diffuser is defined with respect to the adiabatic ring. Since the diffuser fastening bolts for fastening the members and the nozzle fastening bolts for fastening the member that defines the turbine nozzle to the heat insulating ring are provided, heat transfer from the turbine nozzle to the compressor diffuser is suppressed, and a high compressor When efficiency is gained To a member defining a compressor diffuser becomes possible to achieve weight reduction and formation of aluminum-based metal.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a gas turbine showing an embodiment of the present invention.

FIG. 2 is a transverse sectional view of the diffuser.

FIG. 3 is a transverse sectional view of the turbine nozzle.

FIG. 4 is an exploded perspective view of a heat insulating ring and a diffuser fastening bolt.

FIG. 5 is an exploded perspective view of a heat insulating ring, a nozzle fastening bolt, and a diffuser fastening bolt.

FIG. 6 is a vertical cross-sectional view of a gas turbine showing another embodiment.

FIG. 7 is a diagram showing a conventional example.

[Explanation of symbols]

 1 Compressor 2 Compressor Impeller 3 Turbine 4 Turbine rotor 7 Diffuser 9 Rotating shaft 14 Diffuser front plate 15 Diffuser back plate 20 Turbine housing 21 Turbine nozzle 23 Nozzle front plate part 24 Nozzle back plate part 30 Adiabatic ring 36 Diffuser fastening bolts 37 Nozzle fastening For bolt

Claims (1)

[Claims] 1. A compressor impeller and a turbine rotor are provided back to back in close proximity to each other, a compressor diffuser is provided for boosting intake air discharged from the outer peripheral portion of the compressor impeller, and a high temperature from a combustor is provided on the outer peripheral portion of the turbine rotor. In a gas turbine provided with a turbine nozzle that guides gas, an adiabatic ring provided between the compressor diffuser and the turbine nozzle is provided.
The heat insulating ring is provided with a diffuser fastening bolt for fastening a member defining a compressor diffuser, and the heat insulating ring is provided with a nozzle fastening bolt for fastening a member defining a turbine nozzle. Gas turbine flow passage assembly structure.