JPH0281902A - Gas turbine rotor - Google Patents

Abstract

PURPOSE:To enable reductions of the stress concentration and core shearing in a faucet part by introducing a heated air from the high pressure side into a plurality of through ports provided from the upper stream end to the lower stream end on the working face of each disc. CONSTITUTION:A plurality of through ports 9 are provided passing through a front stub shaft 1, each step disc 4, a spacer 5 and a rear stub shaft 2. A high temperature air exhausted from a compressor is introduced into the rear stub shaft 2 through the through ports 9. Hence, the metal temperature in the rear step disc 4 is made nearly equal to that in the rear stub shaft 2, and the thermal elongation difference between the rear step disc 4 and the faucet part in the rear stub part 2 is reduced. Thus, the stress concentration in the faucet part, and also the unbalanced vibration because of the radial core shearing in the faucet part can be reduced. This results in an improvement in the life and reliability of a gas turbine rotor.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a disk stacked gas turbine rotor,
The present invention relates to a gas turbine rotor that reduces stress concentration in the pilot part by reducing the difference in thermal expansion that occurs in the rotor, and also reduces unbalanced vibrations caused by misalignment of the pilot part in the radial direction.

(Prior art) A gas turbine is roughly divided into a compressor, a combustor, and a turbine.The high temperature and high pressure air generated by the compressor is mixed with fuel in the combustor, and the fuel is combusted.
The combustion gas becomes high temperature and high pressure, flows into the turbine and generates power, and is then released into the atmosphere as exhaust gas. Further, a portion of the high temperature and high pressure air generated by the compressor is introduced into the turbine as cooling air for the turbine rotor.

FIG. 4 shows a partial structural sectional view of a conventional turbine;
The figure is a v-v arrow diagram of 4 in FIG.

In these figures, the rotor is a disc stacked rotor, with a front stub shaft 1, a rear stub shaft 2,
It is composed of each stage disk 4 to which the first to third stage moving blades 3 are attached, a spacer 5 inserted between these disks, and a plurality of tie bolts 6 that laminate these structures. .

7 indicates Lo Takabah.

The combustion gas indicated by the white arrow A flows from each stage nozzle 8 to the moving T.
After being blown onto A3 and applying rotational force to them, they are discharged as exhaust gas B.

Solid line arrows a and b in FIG. 4 indicate the flow of cooling air. That is, arrow a is the flow of compressor discharge air, and 30
The temperature is 0°C to 400°C. Furthermore, the bearing indicated by the arrow is sealed air, and the temperature is around 100°C.

The compressor discharge air a is guided to the vicinity of the embedded part of the turbine disk 4 and the rotor blade 3, and the combustion gas A reaches as high as 1100°C.
This prevents high heat from entering the rotor side. the result,
The front stub shaft 1, the disk 4, and the spacer 5 are kept at a temperature of about 400 to 500°C during normal operation.

(Problem to be Solved by the Invention) However, since the rear stub shaft 2 is open to the atmosphere, it is cooled by atmospheric air or, as shown in the figure, cooled to approximately 100°C by bleed air from an intermediate stage of the compressor.
Since this type of bearing is cooled by the seal air, there is a temperature difference of around 300° C. between the final stage disc 4 and the spigot part of the rear stub shaft 2.

As a result, the disc side expands greatly and the shaft side elongates less, resulting in a difference in thermal expansion.If you try to obtain a proper interference during rated operation, an excessive interference is required when the machine is cold, so the spigot section Excessive stress is concentrated. Furthermore, there is a risk that unbalanced vibrations may occur due to misalignment of the spigot part in the radial direction.

Furthermore, since the temperature of the rear stub shaft 2 rises more slowly than other disks 4, etc., low-temperature brittle strength becomes a problem in the case of a cold start.

The present invention has been made to solve the conventional technical problems described above, and improves the lifespan and reliability of the gas turbine rotor by reducing stress concentration in the pilot part and misalignment of the pilot part that occur in the gas turbine rotor. The purpose is to improve.

[Structure of the Invention] (Means for Solving the Problems) The gas turbine rotor of the present invention is a gas turbine rotor in which a plurality of disks in which a large number of blades are embedded are stacked, and are integrated with a front stub shaft and a rear stub shaft. The disc stacked rotor is characterized in that a plurality of through holes are provided in the contact surface of each of the discs from the upstream end of the disc to the trailing end of the disc, and heated air is introduced into the through holes from the high pressure side. It is something.

(Function) In the gas turbine rotor of the present invention configured as described above, high-temperature compressor discharge air is guided to the rear-stage gas turbine shaft through the through hole passing through the front and rear of the rotor. The difference in thermal expansion between shafts can be reduced.

(Example) Next, the present invention will be explained in detail with reference to FIGS. 1 to 3. In these figures, the same parts as in FIGS. 4 and 5 are given the same reference numerals, and explanations of the overlapping parts will be omitted.

FIG. 1 is a partial structural sectional view of a turbine showing an embodiment of the present invention, and FIG. 2 is a view taken along arrows 1--2 in FIG. The gas turbine rotor includes a front stub shaft 1, a rear stub shaft 2, each stage disk 4 in which the first to third stage rotor blades 3 are implanted, a spacer 5 inserted between these disks, and a spacer 5 inserted between these disks. It consists of a plurality of tie bolts 6 that are laminated and integrally colored, and the power of each stage rotor blade is transmitted to the front and rear stub shafts 1.2 by the force of tightening the tie bolts 6.

A feature of the present invention is that a plurality of through holes 9 are provided through the front stub shaft 1, each stage disk 4, the spacer 5, and the rear stub shaft 2.

These through holes 9 are provided on the same circumference of the disk contact surface as the tie bolts 6, in a portion where the tie bolts 6 are not present.

In the turbine rotor of the present invention having such a configuration, high temperature and high pressure compressor discharge air flows into the upstream side of the turbine as indicated by arrow a in order to cool the turbine section. When it comes to the tie bolt circumference, the compressor discharge air enters the through hole 9,
After passing there, it flows into the space between the rotor cover 7 and the rear stub shaft 2. Most of the compressor discharge air that flowed into this space is distributed between the rotor cover 7 and the rear stub shaft 2.
and is discharged into the atmosphere through the exhaust hole 7' of the rotor cover 7.

As described above, the rear stub shaft 2 can be heated by introducing the compressor discharge air having a temperature of 300 to 400'' C into the space between the rotor cover 7 and the rear stub shaft 2.

Therefore, the metal temperatures of the rear disk 4 and the rear stub shaft 2 become approximately equal, and the difference in thermal expansion between the spigot portions of the rear disk 4 and the rear stub shaft 2 is reduced.

This reduces stress concentration in the spigot part and also reduces unbalanced vibrations caused by misalignment of the spigot part in the radial direction. Furthermore, by heating the metal temperature of the rear stub shaft 2 with compressed discharge air, the engine can be warmed up quickly even during cold engine operation, which is also effective in preventing brittle damage.

FIG. 3 shows an embodiment in which a threaded portion 10 is provided at the downstream end of the through hole 9 of FIG. 1, and an orifice 11 for flow rate adjustment is attached thereto.

According to this configuration, if it is difficult to adjust the flow rate using the through hole 9, the flow rate of the compressor discharge air can be adjusted by replacing the orifice 11, and the temperature of the rear stub shaft 2 can be finely adjusted. becomes possible.

[Effects of the Invention] As described above, in the gas turbine rotor of the present invention, a plurality of through holes are provided on the circumference of the rotor, and high temperature air is introduced into these through holes and guided to the downstream side of the turbine. As a result, the difference in thermal elongation that occurs between the final stage disc and the rear stub shaft during operation is reduced, reducing stress concentration in the spigot part and misalignment of the spigot part. The lifespan and reliability of the turbine rotor can be improved.

Further, when an orifice is provided at the end of the through hole, more accurate temperature control can be performed, and the above effects can be brought out even more.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of the main part of a turbine showing an embodiment of the present invention, Fig. 2 is a view taken along the ■-■ arrow in Fig. 1, and Fig. 3 shows another embodiment of the present invention. Figure 4 is an enlarged view of the main parts near the shaft, Figure 4 is a partial sectional view of the main parts of a conventional turbine, Figure 5 is a partial cross-sectional view of the main parts of a conventional turbine.
The figure is a view taken along arrow v-■ in FIG. 4. 11... Orifice agent Patent attorney Norihiko Ken Yudo Daishimaru Ken 1... Front stub shaft 2... Rear stub shaft 3... Moving blade 4. ...Disc 5...Spacer 6...Tie bolt 7...Rotor cover 8...Nozzle 9...Through hole 10.・Screw part Fig. 2 Fig. 3

Claims (1)

[Claims] In a stacked disk rotor for a gas turbine, in which a plurality of disks each having a large number of blades embedded therein are stacked and integrated together with a front stub shaft and a rear stub shaft, the contact surface of each of the disks is covered with a disk from an upstream end of the disk to a trailing end of the disk. 1. A gas turbine rotor characterized in that a plurality of through holes are provided in the rotor, and heated air is introduced into the through holes from a high pressure side.