JPH0680801U - Mounting structure of stator blade segment - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a mounting structure for a stationary blade segment that allows the stationary blade segment to be easily removed from the turbine case. [Structure] In a mounting structure in which a stationary blade segment 4 having a predetermined number of stationary blades 2 and a connecting band 3 that connects the ends of these stationary blades 2 is mounted to a casing 1, engages with a mounting groove 5 of the casing 1. By forming the concave portion 15 on the engaging surface 12 of the flange portion 8 to be formed, the engaging area of the engaging surface 12 is reduced by the amount of the concave portion 15 to reduce the seizure area. Easily remove from casing.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mounting structure for mounting a stationary blade segment that constitutes a turbine of a gas turbine to an inner peripheral surface of a casing, and more particularly to a structure that can be easily removed when the stationary blade segment is overhauled.

[0002]

[Prior art]

 In general, the turbine section of a gas turbine has a structure in which a large number of rotor blades are provided to rotate at a high speed and a stator provided in front of the rotor blades are axially superposed. This stator consists of a large number of stator blade segments with a fixed number of stator blades fixed by inner and outer connecting bands.Each stator blade segment is attached to the inner peripheral surface of the turbine casing by the outer connecting bands. It has a fixed configuration.

FIG. 4 to FIG. 6 show a conventional example of a mounting structure of a vane and a turbine casing. This mounting structure has a predetermined number of stationary blades 2 ... In the circumferential direction inside a cylindrical turbine casing 1 composed of two semi-cylinders, and a connecting band 3 connecting these stationary blades 2. A large number of vane segments 4 are arranged, and the connecting bands 3 of the vane segments 4 are engaged with mounting grooves 5 formed on the inner peripheral surface of the casing 1 extending in the circumferential direction. There is. The mounting groove 5 is composed of a concave groove 6 extending in the circumferential direction of the casing 1, and engaging grooves 7, 7 formed by notching both inner side surfaces of the concave groove 6 facing each other in the axial direction of the casing 1. There is. On the other hand, the outer peripheral portion of the connecting band 3 is formed with annular flange portions 8 and 8 projecting in the axial direction. The flange portions 8 and 8 are engaged with the engaging grooves 7 and 7. A vane segment 4 is attached to casing 1 by. In FIG. 4, reference numeral 9 represents a rotor blade attached to the rotor.

[0004]

By the way, when removing the stationary blade segment 4 from the casing 1 when performing overhaul after operating the gas turbine at a high temperature for a long time, a circumferential force is applied to the stationary blade segment 4. The flanges 8 and 8 are slid in the engagement grooves 7 and 7 and are moved to two parts of the casing 1 to be removed. However, when operating at high temperature for a long time, the flange portions 8 and 8 and the engagement grooves 7 are removed. , 7 do not stick to each other due to seizure, so that the flanges 8 and 8 are moved in the circumferential direction in the engagement grooves 7 and 7, that is, the casing 1 to the stator blade segment 4 are moved. There was a problem that it became difficult to remove.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a mounting structure for a stationary blade segment that allows the stationary blade segment to be easily removed from the turbine case.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the mounting structure of a stator blade segment of the present invention includes a stator blade segment having a predetermined number of stator blades and a connecting band that connects the tips of the plurality of stator blades in a casing. In the mounting structure for mounting, a recess is formed on at least one engagement surface where the connecting band of the vane segment and the mounting groove of the casing are engaged with each other.

[0007]

[Action]

 In the mounting structure of the stator blade segment of the present invention, the engagement area of the engagement surface is reduced by the amount of the recess formed in the engagement surface, the seizure area is reduced, and the air flows through the recess. Since the heat generated in the engagement surface can be released, seizure can be prevented or minimized, and thus the vane segment can be easily removed from the casing.

[0008]

【Example】

 An embodiment of a stator blade segment mounting structure according to the present invention will be described below with reference to FIGS. 1 to 3. In these figures, the same components as those shown in FIGS. 4 to 6 are designated by the same reference numerals to simplify the description.

The turbine casing 1 has a cylindrical shape in which two semi-cylinders are separably assembled, and a plurality of the mounting grooves 5 are formed on the inner peripheral surface thereof at predetermined intervals in the axial direction (see FIG. 1). In the figure, one mounting groove 5 is shown as a representative thereof. As described above, each mounting groove 5 is composed of the concave groove 6 extending in the circumferential direction and the engaging grooves 7, 7 formed on both inner side surfaces of the concave groove 6.

On the other hand, the stationary vane segment 4 is provided inside the casing 1 so as to face each mounting groove 5. The stationary vane segment 4 has a configuration in which a predetermined number (usually 3 to 4) of radially extending stationary vanes 2 ... Are connected by the connecting band 3 and the base end is connected by the fixed band 10. ing. As shown in FIG. 1, the connecting band 3 is formed by projecting in the axial direction from a band body 11 having a U-shaped cross-section that opens to the outside, and the tip ends of the opposing wall portions 11a and 11a of the band body 11. It is composed of flange portions 8 and 8. The wall portions 11a, 11a are set such that the distance between them is narrower than the width of the recessed groove 6 of the mounting groove 5, and the flange portions 8, 8 have the thickness thereof which is the engagement groove 7 of the mounting groove 5. , 7 is set to be almost equal to the width.

In the connecting band 3, the band body 11 is moved in the concave groove 6 of the mounting groove 5 in the circumferential direction, and the flange portions 8, 8 are slid in the engaging grooves 7, 7 in the circumferential direction. Then, the structure is detachable by moving the casing 1 to two parts.

In addition, on the upper and lower surfaces of the flange portion 8 of the connecting band 3, that is, on the engaging surfaces 12 and 12 that abut and engage with the upper and lower inner wall surfaces of the engaging grooves 7 and 7, a large number of concave portions 15 ... Are formed at predetermined intervals along the circumferential direction. These recesses 15 are formed by cutting out a part of the engaging surfaces 12, 12, and the notch depth is appropriately set so that the surface adjacent to each recess 15 is within the engaging grooves 7, 7. The contact surface 16 is in contact with the wall surface.

As described above, by forming the recesses 15 ... In the engagement surfaces 12, 12 of the flange portion 8, the recesses 15 ... Do not come into contact with the inner wall surfaces of the engagement grooves 7, 7, and the contact surfaces are contacted. Only 16 ... will come into contact. Therefore, the contact area between the engagement surfaces 12 and 12 becomes small, so that after the gas turbine is operated at high temperature for a long time, seizure does not occur between the engagement surfaces 12 and 12 of the flange portion 8 and the inner wall surface of the engagement groove 7. Even if it occurs, since the seizure area is small, the flange portion 8 can be easily removed from the engagement groove 7, that is, the stationary blade segment 4 can be easily removed from the casing 1.

Further, since the recesses 15 are formed, the air flows through the recesses 15, which causes the inner wall surface of the engagement groove 7 and the engagement surface 12 (contact surface 16) of the flange portion 8. Since it is possible to release the heat generated at the contacting portions with and, seizure can be prevented or suppressed to a minimum, so that the vane segment 4 can be easily removed from the casing 1 also in this respect.

In the above embodiment, the recesses 15 formed in the upper and lower engaging surfaces 12, 12 of the flange portion 8 are arranged to face each other in the vertical direction, but the present invention is not limited to this, and the appropriate arrangement is possible. You may form it. Further, in the above embodiment, the concave portion 15 is formed on the engaging surface 12 of the flange portion 8. However, the present invention is not limited to this, and the concave portion 15 is formed on the inner wall surface of the engaging groove 7 with which the engaging surface 12 abuts. Alternatively, it may be formed on both the engagement surface 12 and the inner wall surface.

[0016]

[Effect of device]

 As described above, according to the stationary blade segment mounting structure of the present invention, the stationary blade segment having a predetermined number of stationary blades and the connecting band connecting the tip portions of these stationary blades is mounted to the casing. In the above, since the concave portion is formed in at least one of the engaging surfaces where the connecting band of the vane segment and the mounting groove of the casing are engaged, the engaging area of the engaging surface is reduced by the amount of the concave portion. Therefore, even if seizure occurs on the engagement surface after the gas turbine is operated at a high temperature for a long time, the seizure area is small, so that the stator blade segment can be easily removed from the casing.

Further, since the recesses are formed, the air flows through these recesses, whereby the heat generated in the engagement surface can be released, so that seizure can be prevented or suppressed to a minimum. In this respect also, the vane segment can be easily removed from the casing.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of a stator blade segment mounting structure of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a perspective view showing a main part of a connecting band in the stator blade attachment structure of the present invention.

FIG. 4 is a sectional view of a main part showing an example of a conventional stator blade segment mounting structure.

5 is a sectional view taken along line BB in FIG.

FIG. 6 is a perspective view showing a main part of a connecting band in a conventional stator blade segment mounting structure.

[Explanation of symbols]

 1 Casing 2 Stator Blade 3 Connection Band 4 Stator Blade Segment 5 Mounting Groove 7 Engaging Groove 8 Flange Part 12 Engaging Surface 15 Recess

Claims (1)

[Scope of utility model registration request] 1. A stationary vane, which is arranged in a circumferential direction at a predetermined number at a predetermined interval along a circumferential direction, inside a cylindrical casing that is dividable in the circumferential direction, and a connecting band for connecting the tip portions of these vanes. A plurality of stationary vane segments having a connecting band of these stationary vane segments are engaged with a mounting groove formed to extend in the circumferential direction on the inner peripheral surface of the casing. A mounting structure for a stationary blade segment, characterized in that a recess is formed on at least one engagement surface where the coupling band of the stationary blade segment and the mounting groove of the casing are engaged with each other.