JPH1047006A - Heat recovery gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid complicating a structure unnecessary, and carry out cooling by both means of steam and air with a simple structure by cooling the rotor blade of a forward step by means of steam, and by cooling the rotor blade of a backward step by means of air, in the rotor of a gas turbine. SOLUTION: Cooling steam is supplied from a rotor 1 direction bypassing a hole having the space of a spindle bolt 2, and flows into a rotor blade forward chamber 3. A rotor 4, a rotor blade 5, a rotor 6, and a rotor blade 7 are steam- cooled in order, and recovered from the cooling steam hole 8 of the rotor 1. Extracted air is led into a turbine chamber 9, and cooling air is led to a seal fin part 15 bypassing holes of the outer shroud 12 of a stator blade 11 before a rotary blade 10, the inside of the stator blade 11, an inner shroud 13, and an inner shroud lower part 14. Finally, it flows into the rotor blade 10, and discharged to a gas main flow. Air cooling is taken in skillfully without interfering with steam cooling structure part, and air cooling is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine rotor having a steam cooling blade and an air cooling blade.

[0002]

2. Description of the Related Art In order to improve the thermal efficiency of a gas turbine, it has been considered to cool gas turbine blades with steam.
In this type, a new rotor having a passage for supplying steam to the turbine rotor blade and collecting the cooled steam is required.

In this case, the cooling steam is extracted from a steam turbine of a combined cycle, but leakage is limited as much as possible on the steam side cycle.

FIG. 2 is a cross-sectional view of a turbine portion of a gas turbine having a steam cooling blade which has been conventionally considered.

As shown in FIG. 2, the cooling steam flows from the rotor 31 on the last stage side toward the spindle bolt 3 of the rotor.
The air is supplied through the second gap hole 33 and flows into the first-stage bucket front chamber 34. After cooling them through the rotor 35 and the rotor blade 36, the second-stage rotor 37
The steam is cooled by passing the steam through the second-stage rotor blades 38 in order, and is recovered from the cooling steam holes 39 of the final-stage rotor 31.

[0006]

The supply and recovery of the cooling steam from the steam-cooling rotor blades are performed according to the above-described route. However, in consideration of the effects such as the efficiency and the output, the rear stage (the illustrated example) is used. Indicates the third stage blade), it is possible to cool with a little air.

However, in the type shown in FIG. 2, since the supply / recovery passage of the cooling steam is complicated, there is no way to provide a cooling air passage on the rotor side even if only some of the moving blades are air-cooled. It was difficult to secure cooling air.

[0008] The present invention has been made in view of such a point, and an object of the present invention is to provide a type having both steam cooling and air cooling.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In a gas turbine rotor having steam-cooled moving blades, a front-stage moving blade and steam-cooling are provided, and a rear-stage moving blade is provided. The air-cooled heat-recovery type provides the turbine, and the front-stage rotor blade, which has a large effect on efficiency, output, etc., is steam-cooled, and the rear-stage rotor blade, which has a small effect, is air-cooled. .

Further, the present invention provides a heat recovery type gas turbine in which the air-cooled rear-stage moving blade supplies cooling air through a stationary vane in front of the air-cooled rear-stage moving blade. The cooling air is supplied to the rear stage rotor blades by guiding the cooling air through the outer shroud, the stator blade case, and the inner shroud of the stator vane disposed in front of the blade for cooling the air. It was done.

Further, according to the present invention, the vane for passing the cooling air forms a flow path from the vane to the rotor blade via the rotor,
The cooling air communication portion from the stator blade to the rotor provides a heat recovery type gas turbine located radially inward of the rotor from the cooled portion of the rotor blade and the cooling air outlet hole, and the cooling air flows from the stator blade to the rotor. The cooling air communication position from the stationary blade to the rotor is determined by the radius of the rotor from the cooled portion of the rear blade and the outlet position of the cooling air from the cooled portion. The cooling air is reliably circulated by utilizing the pressure difference between the two positions by setting the inner position in the direction.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG.

1 is a rotor at the last stage, 2 is a spindle bolt, 3 is a first stage rotor blade front chamber, 4 is a first stage rotor, 5
Is a first stage rotor, 6 is a second stage rotor, 7 is a second stage rotor, 8
Is a cooling steam hole, 9 is a cabin, 10 is a third stage rotor blade, a so-called air-cooled rotor blade, 11 is a stationary blade arranged in front of the final stage rotor blade 10, and 12 is an outside of the stationary blade 11. Shroud, 13
Is also the inner shroud, 14 is the lower part of the inner shroud,
Reference numeral 15 denotes seal fins, and reference numeral 16 denotes a plurality of holes provided on the outer periphery of the third-stage rotor 17 in the circumferential direction.

In this embodiment having such a configuration, the cooling steam is supplied from the direction of the rotor 1 on the final stage side through the gap hole of the spindle bolt 2 of the rotor, and the first cooling steam is supplied to the first stage.
It flows into the step rotor blade front chamber 3.

After cooling them through the rotors 4 and the moving blades 5, they are steam-cooled in the same order as the second-stage rotor 6 and the second-stage moving blades 7, and from the cooling steam holes 8 of the last-stage rotor 1. Collected.

On the other hand, the cooling air is extracted from a gas turbine compressor (not shown). The seal fin portion 15 passes through holes in the stator vane 11, the inner shroud 13, and the lower portion 14 of the inner shroud.
Leads to.

The cooling air discharged to the seal fin portion 15 is supplied from a plurality of holes 16 on the outer periphery of the rotor 17 to the rotor 1.
7 and the rotor blades 10, but the seal fin portion 1
The cooling air discharged to the nozzle 5 is sucked from the rotor hole by the magnitude of the absolute value of the bleed pressure and the pump action effect due to the difference ΔH between the height positions of the rotor inlet hole and the rotor outlet hole, and enters the moving blade 10. It reliably flows in and is finally released into the main gas stream.

In this embodiment, the air cooling is skillfully incorporated without interfering with the steam cooling structure in this way, thereby enabling the air cooling.

Although the present invention has been described with reference to the illustrated embodiments, the present invention is not limited to these embodiments.
It goes without saying that various changes may be made to the specific structure within the scope of the present invention.

[0020]

As described above, according to the heat recovery type gas turbine rotor according to the present invention, the structure of the steam-cooled gas turbine employed for improving the efficiency, output and the like is prevented from being unnecessarily complicated, and is simplified. With this simple structure, both cooling by steam and air can be made possible.

According to the second aspect of the present invention, the intake of the cooling air is specified to be performed through the inside of the stationary blade in front of the moving blade for performing the air cooling, so that the overall structure is simplified and made compact. Is assured and can be made extremely feasible.

According to the third aspect of the present invention, the cooling air reaching the stationary blade, the rotor, and the target moving blade has a pressure between the transition position from the stationary blade to the rotor and the transition position to the moving blade. Due to the difference, the movement of the cooling air becomes reliable and accurate, and the intended cooling function can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a steam-air cooling turbine according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a steam cooling turbine that has been conventionally considered.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Final stage rotor 2 Spindle bolt 3 First stage moving blade front chamber 4 Rotor 5 First stage moving blade 6 Second stage rotor 7 Second stage moving blade 8 Cooling steam hole 9 Chamber 10 Air cooled moving blade 11 Stationary blade 12 outer shroud 13 inner shroud 14 outer shroud lower part 15 seal fin 16 hole 17 third stage rotor

Claims (3)

[Claims] 1. A heat recovery type gas turbine in which a rotor of a front stage is steam-cooled and a rotor of a rear stage is air-cooled. 2. The heat recovery type gas turbine according to claim 1, wherein the air-cooled rear stage moving blade supplies cooling air through a stationary vane in front thereof. 3. The stationary blade for passing the cooling air forms a flow path from the stationary blade to the rotor via the rotor, and a cooling air communication part from the stationary blade to the rotor is a cooled part of the rotor. The heat recovery type gas turbine according to claim 2, wherein the heat recovery type gas turbine is positioned radially inward of the rotor from the cooling air outlet hole.