JPH0533603A - Steam turbine - Google Patents

Abstract

PURPOSE:To prevent a turbine easing and a rotor from being corroded by providing spaces which are partitioned by the turbine easing, fin, and rotor near the air of ground, and introducing anti-corrosion gas into the spaces. CONSTITUTION:Spaces 11-13 are partitioned by a steam turbine easing 14, a fin 15 which is fixed at the easing 14, and a rotor 16. Besides, the pressure in a space 13 which is the nearest the air side of the turbine outside part 17 is always controlled slightly higher than the atmospheric pressure and the pressure in the space 11. The pressure in the space 11 is always controlled to be lower than the pressure in a space 13 and the pressure in the space 12. Moreover, anti-corrosion gas 19 is introduced into the space 13. With this constitution, the space 11 becomes a space where steam in a turbine inside 18 and anti- corrosion gas 19 are mixed, thus it is possible to prevent corrosive atmosphere from being generated.

Description

Detailed Description of the Invention

[0001]

This invention relates to steam turbines,
More specifically, it relates to the structure of a gland seal portion of a steam turbine.

[0002]

2. Description of the Related Art FIG. 3 shows a structure of a gland of a high-pressure steam turbine which has been already proposed. In FIG. 3, the gland is a passenger compartment 1 of the steam turbine and the passenger compartment 1
The spaces 4 and 5 are defined by the fin 2 and the rotor 3 which are fixed to each other (usually fixed via a packing ring and a spring).

The pressure in the space 4 is always set to be lower than the atmospheric pressure and the pressure in the space 5 to prevent steam inside the turbine 6 from leaking to the atmosphere outside the turbine 7. There is. In addition, the arrow in FIG. 3 has shown the steam flow direction, and the gland steam 8 of a high pressure turbine is guide | induced as a gland steam of a low pressure turbine.

[0004]

However, in the above-described conventional steam turbine gland, the space 4
Inside, mixing of steam and air will always occur. Then, the mixture of high-temperature steam and air, particularly oxygen in the air, causes a corrosive environment in the space 4. In particular, when H ₂ S, NH _3, etc. are present in the steam such as geothermal steam, the corrosive environment becomes more severe, and the turbine casing 1, which is in contact with the space 4,
There is a problem that the rotor 3 is severely corroded.

The present invention has been made in order to solve the problems of the prior art, and an object thereof is to provide a steam turbine capable of preventing corrosion of a turbine casing and a rotor.

[0006]

In order to solve the above-mentioned problems, the present invention relates to a steam turbine having a space defined by a turbine casing and fins and rotors fixed to the turbine casing. , On the side close to the ground atmosphere,
Further, a space defined by the turbine casing, the fins and the rotor is provided, and a non-corrosive gas is introduced into the space.

[0007]

According to the above means, a space is further added to the side of the gland close to the atmosphere, and a non-corrosive gas is introduced into the space, whereby air generated in the conventional gland,
In particular, it is possible to prevent corrosion of the turbine casing and the rotor due to the mixed fluid of oxygen and steam in the air.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic sectional view of a gland portion showing an embodiment in which the present invention is applied to a high pressure steam turbine.
In the structure of this embodiment, the three spaces 11, 12, 1
3 are provided, and these spaces 11 to 13 are provided in the passenger compartment 14 of the steam turbine and the fins 15 fixed to the passenger compartment 14.
And the rotor 16 are defined.

The pressure in the space 13 closest to the atmosphere outside the turbine 17 is constantly controlled to be slightly higher than the atmospheric pressure and the pressure in the space 11, while the pressure in the space 11 is equal to the pressure in the space 13 and the pressure in the space 13. The pressure is controlled to be always lower than the pressure in the space 12.

Further, in the space 13, the inside 18 of the turbine is filled with an inert gas (He, Ar, etc.) or nitrogen.
The non-corrosive gas 19 that does not generate a corrosive environment even when mixed with the steam of the above is introduced.

With such a structure, the space 11 becomes a space in which the steam inside the turbine 18 and the non-corrosive gas 19 are mixed, and the generation of a corrosive environment can be prevented. Note that FIG.
The other arrows in the inside indicate the steam flow direction, and the ground steam 20 of the high-pressure turbine is guided as the ground steam of the low-pressure turbine.

Next, FIG. 2 is a schematic diagram showing an embodiment in which the present invention is applied to a low pressure steam turbine. In FIG. 2, 11 to 13 are spaces, 14 is a turbine casing, 15 is a fin, and 16 is a rotor. Then, the ground steam 20 from the space 12 of the high-pressure turbine gland shown in FIG. 1 is introduced into the space 12, and a control valve is provided in the middle of the introduction pipe 21 for introducing the ground steam 20. 22 and a control device 23 are provided.

The space 13 is connected to a He cylinder 24, and a control valve 26 and a control device 27 are provided in the middle of a pipeline 25 connecting the He cylinder 24 and the space 13. Therefore, in this embodiment, He is introduced into the space 13 as an inert gas.

Further, the space 11 is connected to a cooler 28, and the mixture of the steam and the non-corrosive gas from the space 11 is discharged to the atmosphere or drained through the cooler 28. Reference numeral 29 indicates a fan, and 30 indicates a chimney.

[0016]

As described above, according to the present invention, in the steam turbine, a space defined by the turbine casing, the fins, and the rotor is further provided on the side close to the atmosphere of the gland, and the space inside the space is not defined. By introducing the corrosive gas, it is possible to reliably prevent the corrosion of the turbine casing and the rotor caused by the air generated in the conventional gland, particularly the mixed fluid of oxygen and steam in the air. By thus preventing corrosion of the turbine casing and the rotor, it is possible to improve the reliability of the device and reduce maintenance costs.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a gland portion showing an embodiment in which the present invention is applied to a high-pressure steam turbine.

FIG. 2 is a schematic configuration diagram showing an embodiment in which the present invention is applied to a low pressure steam turbine.

FIG. 3 is a schematic sectional view showing a gland of a conventional high-pressure steam turbine.

[Explanation of symbols]

 11 space 12 space 13 space 14 turbine casing 15 fins 16 rotor 17 turbine outside 18 turbine inside 19 non-corrosive gas 20 ground steam 24 He cylinder

Claims (1)

Claim: What is claimed is: 1. A steam turbine having a space defined by a turbine casing, a fin fixed to the turbine casing, and a rotor. A steam turbine characterized in that a space defined by a passenger compartment, fins and a rotor is provided, and a non-corrosive gas is introduced into the space.