JPH07324633A - Cooling air feeder for gas turbine rotor - Google Patents

Abstract

PURPOSE:To prevent the temperature of main gas from dropping by passing cooling air of a gas turbine rotor through a labyrinth seal, and making the cooling air flow out behind the first stage stationary blade of a turbine. CONSTITUTION:A nozzle 3 whose jetting port is directed in a farther direction from a labyrinth 1 and ranges over the whole periphery is mounted in the cooling air hole 6 of an intermediate shaft cover 2 (stationary part) provided with the labyrinth 1. At a farther position from the labyrinth than the nozzle jet port, a cooling air hole 7 is drilled in a rotor air separator 4 to guide jetting air to the surface part of a rotor 5 (rotating part).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a gas turbine rotor cooling air inlet.

[0002]

2. Description of the Related Art FIG. 2 is a schematic vertical sectional view showing an example of a cooling air introducing portion of a conventional gas turbine rotor, and FIG. 3 is a detailed vertical sectional view in the vicinity of an intermediate shaft cover surrounded by a chain line III in FIG. is there.

The cooling air cools a part of the discharge air of the air compressor and is introduced into the gas turbine through the cooling air pipe (11),
It is discharged to the C portion of the intermediate shaft cover (12) (stationary portion).
The cooling air discharged to the portion C passes through the gap D provided in the intermediate shaft cover (12) and the hole E formed in the rotor air separator (13) and the surfaces of the rotor (14) and the disk (15). Is further cooled, and then the blade bases and blades are cooled through the holes F formed in the disk (15) to escape to the atmosphere on the exhaust side.

Further, a part of the air is generated by the intermediate shaft cover (12).
Through the labyrinth seal (16) from the gap D to the rear of the turbine first stage vane (17) (to the right in the figure), and to the rear stage together with the main gas flow. Still another part flows out to the compressor rotor (18) side, and flows out to the discharge air side from the vane seal part.

[0005]

In the conventional cooling air introducing section, a part of the cooling air passes through the labyrinth seal (16) from the gap provided in the intermediate shaft cover D section and the turbine first stage stationary blade (17). ) Spilled out behind. Therefore, the temperature of the main gas is lowered and the gas turbine performance is lowered.

[0006]

In order to solve the above-mentioned conventional problems, the inventor of the present invention has a cylindrical rotor for connecting a turbine disk to a compressor rotor and a space outside the rotor. Enclosed, a rotor air separator rotating integrally with the rotor, and an intermediate shaft cover provided via a labyrinth outside the rotor air separator, and cooling air is supplied from the outside of the intermediate shaft cover. A cooling air hole penetrating the inside and outside of the intermediate shaft cover closer to the compressor rotor than the labyrinth, and a jet port provided inwardly of the cooling air hole over the entire circumference in a direction away from the labyrinth. Cooling air passing through the inside and outside of the rotor air separator at a position farther from the labyrinth than the nozzle facing and the jet outlet of the nozzle. DOO proposes a cooling air supply device for a gas turbine rotor, comprising a.

[0007]

The present invention has the above-mentioned structure, and the jet port is directed in the direction away from the labyrinth over the entire circumference inward of the cooling air hole penetrating the inside and outside of the intermediate shaft cover closer to the compressor rotor than the labyrinth. Since the nozzle is provided, the static pressure of the cooling air that enters the labyrinth seal portion on the back surface of the nozzle ejection port decreases due to the suction effect of the flow velocity due to the flow velocity of the cooling air ejected from the nozzle, The differential pressure decreases. Therefore, the amount of cooling air flowing out to the rear of the vane is reduced, and the main gas temperature cannot be lowered. As a result, the performance of the gas turbine is not deteriorated.

[0008]

1 is a longitudinal sectional view (corresponding to FIG. 3) near an intermediate shaft cover in an embodiment of the present invention.

In this embodiment, the intermediate shaft cover (2) (stationary part) to which the labyrinth (1) is attached is opened at a position closer to the compressor rotor (left side in the figure) than the labyrinth (1). Inward of the cooling air hole (6) all around,
A nozzle (3) is provided, the jet of which faces away from the labyrinth. The nozzle (3) may be formed integrally with the intermediate shaft cover (2) or may be separately manufactured and attached. In this embodiment, a cooling air hole (7) penetrating the inside and the outside of the rotor air separator (4) is further formed at a position farther from the labyrinth (1) than the ejection port of the nozzle (3).

The cooling air is guided to the surface of the rotor (5) to cool the rotor (5) as shown by the arrow. In the present embodiment, the static pressure of the cooling air entering the labyrinth seal portion A on the back surface of the ejection port of the nozzle (3) decreases due to the suction effect due to the flow velocity of the cooling air ejected from the nozzle (3). The pressure difference with the rear of the step vane (not shown) becomes small. As a result, the amount of cooling air flowing out to the rear portion of the vane is reduced and the decrease in the main gas temperature is suppressed, so that the performance deterioration of the gas turbine is prevented.

[0011]

According to the present invention, the pressure difference between the cooling air pressure entering the labyrinth seal portion and the pressure at the rear portion of the first stage vane is reduced by the nozzle action, and the amount of cooling air flowing out to the rear portion of the vane is reduced. As a result, the main gas temperature is prevented from lowering, and the gas turbine performance does not deteriorate.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of the vicinity of an intermediate shaft cover according to an embodiment of the present invention.

FIG. 2 is a schematic vertical cross-sectional view showing an example of a cooling air introduction part of a conventional gas turbine rotor.

FIG. 3 is a detailed vertical sectional view of the vicinity of the intermediate shaft cover, which is surrounded by a chain line III in FIG.

[Explanation of symbols]

 (1) Labyrinth (2) Intermediate shaft cover (3) Nozzle (4) Rotor air separator (5) Rotor (6), (7) Cooling air hole

Claims (1)

[Claims] 1. A cylindrical rotor for connecting a turbine disk to a compressor rotor, a rotor air separator surrounding the outside of the rotor with a gap, and rotating integrally with the rotor, and a rotor air separator. An intermediate shaft cover provided via a labyrinth to the outside, wherein cooling air is supplied from the outside of the intermediate shaft cover, wherein the intermediate shaft cover closer to the compressor rotor than the labyrinth. A cooling air hole penetrating the inside and outside, a nozzle provided inwardly of the cooling air hole around the entire circumference, the nozzle facing in a direction away from the labyrinth, and a position farther from the labyrinth than the jetting port of the nozzle. Cooling air supply for the gas turbine rotor, characterized in that it has cooling air holes penetrating inside and outside the rotor air separator. apparatus.