JPH03100336A - Variable control mechanism of gas turbine - Google Patents

Abstract

PURPOSE:To contrive the improvement of control accuracy by providing a fixed ring positioned concentrically with a casing and supported in a condition of restricting the vertical and horizontal directions, movable ring supporting mechanism supported to this fixed ring and a movable part driving mechanism supported to a movable ring, in the periphery of the casing. CONSTITUTION:By a temperature during normal operation, when the center of a casing 1 is moved in a vertical direction by thermal elongation, flange upper surfaces 6c, 6d of the casing 1 are brought into contact with lower surfaces of keys 11a, 11b of a fixed ring 2 and restricted in the vertical direction. While, when the casing 1 performs thermal elongation in a horizontal direction, a top part key 12 is fitted into a groove 10 of the casing 1 with no relative displacement generated between the casing 1 and the ring 2. The fixed ring 2 and a movable ring 3 are held to a low temperature by cooling water, further in the ring 3, heat from the casing 1 is isolated by a heat insulating plate 15. Consequently, when the ring 3 is turned in the peripheral direction by the driving part 22 of a movable part driving mechanism 5 to move a plurality of movable parts 26, these parts are moved simultaneously in the same distance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable control mechanism for a gas turbine, and in particular to a variable control mechanism for a gas turbine suitable for controlling the drive of movable parts with high precision in response to thermal displacement of a casing. Concerning variable control mechanism.

[Conventional technology]

Conventional variable control mechanisms for gas turbines generally have a cylindrical shape, and a movable ring is provided on the outer periphery of the casing.By rotating the movable ring in the circumferential direction, the inside of the casing can be controlled via a link mechanism or a gear mechanism. The component is configured to operate.

When the movable ring is slidably supported on the outer periphery of the casing in this way, a method is required to absorb the amount of thermal expansion of the casing and the movable ring during operation.

Therefore, conventionally, a plurality of rollers are provided on the outer circumference of the casing, and only the inner circumference side of the movable ring is supported by the plurality of rollers.

Note that related mechanisms of this type include, for example, Japanese Unexamined Patent Publication No. 48-45912.

[Problem to be solved by the invention]

In the above conventional technology, the casing and movable ring are set in consideration of the amount of thermal expansion during operation.

However, since the roller support mechanism cannot absorb the difference in thermal elongation due to the difference in temperature rise between the casing and the movable ring from startup to the rated operating state, the positional relationship between the casing and the movable ring changes. .

In particular, in the conventional technology mentioned above, only the inner circumferential side of the movable ring is supported by rollers installed on the outside of the casing, so the movable ring, which is designed and assembled based on the difference in the maximum thermal elongation in the rated state, does not support the casing during transient periods. There was a problem in that the positional relationship between the casing and the movable ring changed significantly, causing variations in the amount of movement of parts inside the casing, resulting in a decrease in control accuracy.

An object of the present invention is to reduce the deviation of the relative center positions of the casing and the movable ring even if the casing undergoes thermal displacement during the transition period of load operation of a gas turbine, and to enable highly accurate drive control of the movable parts. An object of the present invention is to provide a variable control mechanism for a gas turbine.

[Means to solve the problem]

In order to achieve the above object, in the variable control mechanism for a gas turbine of the present invention, a fixed ring is provided around the casing and is supported concentrically with the casing while being restrained in the vertical and horizontal directions. a movable ring support mechanism that rotatably supports a movable ring supported by the fixed ring and located concentrically with the casing; and a movable ring support mechanism that is supported by the movable ring and drives movable parts by rotation of the movable ring. A movable parts sliding mechanism is provided.

Further, in order to restrain each other in the vertical and horizontal directions with a simple configuration, a plurality of flanges protruding horizontally are provided on the outer peripheral surface of the casing at positions facing each other in the horizontal direction. The lower surface of a plurality of keys protruding horizontally is provided on the upper surface of the flange at a position horizontally opposite to the inner peripheral surface of the fixing ring, and the lower surface of a plurality of keys is movable in the horizontal direction, and a key groove is provided on the top of the outer peripheral surface of the casing,
A key at the top of the inner circumferential surface of the fixed casing is fitted into the keyway so as to be slidable in the vertical direction.

Further, the fixing ring is provided with a cooling mechanism to prevent thermal deformation.

The movable ring is also provided with a cooling mechanism to prevent thermal deformation.

[Effect]

In the present invention, the fixing ring arranged around the casing is located concentrically with the casing, is supported in a vertically and horizontally restrained state, and is maintained at a low temperature with cooling water, so that the casing can be When the fixing ring moves vertically and horizontally, the fixing ring follows the casing and moves vertically and horizontally, thereby preventing relative displacement between the two.

Further, the movable ring rotatably supported by the movable ring support mechanism supported by the fixed ring is maintained at a low temperature with cooling water to reduce thermal displacement. Therefore, the movable ring can prevent a temperature difference from occurring with the fixed ring, and can also prevent mutual positional deviation due to thermal expansion of the casing.

Furthermore, since the movable parts are driven through the movable part sliding mechanism by the rotation of the movable ring, variations in the amount of movement of the plurality of movable parts are reduced, and control accuracy can be improved.

〔Example〕

Hereinafter, a description will be given of FIGS. 1 to 5 showing a variable control mechanism for a gas turbine, which is an embodiment of the present invention.

In Fig. 1, 1 is a casing, 2 is a fixing ring, and 3 is a casing.
is a movable ring, and 4 is a movable ring support mechanism.

5 is a movable parts drive mechanism.

The casing 1 has a cylindrical shape, and two horizontally protruding flanges 6 are provided at horizontally opposing positions on the outer periphery of the casing 1.
a, 6b are fixed to the two flanges 6a.

It is supported by the base 8 in a positioned state by the support 7 via the support 6b. The above two flanges 6a, 6
b is processed into a smooth horizontal surface so that the center of the casing 1 is located on the horizontal line connecting the upper surfaces 6c and 6d, and key presses 9a and 9b are fixed on the upper surfaces 6c and 6d, respectively, to project upward. ing.

Further, the casing 1 has a key groove 10 formed at the top of its outer circumferential surface, with the center line in the vertical direction passing through the center of rotation of the casing 1 as the center in the width direction (circumferential direction).

The fixing ring 2 is located concentrically with the casing 1, protrudes horizontally inward at opposing horizontal positions on its inner peripheral surface, and has its center located on a horizontal line connecting its lower surfaces lie and lid. keys 11a.

11b, and a top key 12 whose center in the width direction (circumferential direction) is a vertical center line passing through the center of the fixing ring 2. The two keys 11a and llb have a lower surface 11c, and the lid has the two flanges 6a.

6b is supported movably only in the horizontal direction on the upper surfaces 6c and 6d, and has holes (
(not shown). Further, the top key 12 is fitted into the key groove 10 so as to be slidable only in the vertical direction. Therefore, the fixing ring 2 is supported by the casing 1 concentrically and restrained in the vertical and horizontal directions.

Further, as shown in FIGS. 2 and 3, the fixing ring 2 has a cooling water passage 13 formed inside its outer surface, and a water cooling jacket 1 for keeping the fixing ring 2 at a low temperature.
4 is fixed, and a heat shield plate 15 is fixed to the lower surface of the casing 1, protruding inwardly to block heat from the casing 1.

As shown in FIGS. 2 and 3, the movable ring 3 is arranged concentrically and parallel to the casing 1 at intervals, and has a cooling water passage formed inside on its outer surface. Water cooling jacket 17 for keeping ring 3 at low temperature
is fixed, and a convex portion 18 is fixed at the center of the inner periphery.

The plurality of movable ring support devices 4 are installed in the circumferential direction of the inner surface of the fixed ring 2, and as shown in FIG. two rollers 20a into which 18 is inserted;
20b, and the movable ring 3 is positioned in the axial direction of the shaft 19 by the two rollers 20a and 20b via the convex portion 18, and supports the inner circumference thereof evenly.

The movable parts drive mechanism 5 is supported by the base 8,
A drive unit 22 that rotates the movable ring 3 in the circumferential direction via a connecting rod 21, a shaft 23 fixed to a side surface of the movable ring 3 as shown in FIG.
It consists of a connecting frame 24 whose one end is supported, and a link 25 whose one end is connected to the shaft of the movable part 26 and the other end is connected to the other end of the connecting frame 24.

Therefore, in the movable parts drive mechanism 5, when the connecting rod 21 is moved by the drive section 22 in the direction of the arrow shown in FIG. 1 and the movable ring 3 is rotated in the circumferential direction, the shaft 2 , the other end of the link 25 swings in the direction of the arrow shown in FIG. 2 via the connection frame 24, and the movable part 26 at one end rotates in the direction of the arrow. Therefore,
When a plurality of movable parts 26 are installed, the plurality of movable parts 26 can be moved by the same amount at the same time.

Since the gas turbine variable control mechanism according to the present invention is configured as described above, the temperature during normal operation tends to be higher in the casing 1 and lower in the fixed ring 2 and the movable ring 3, and the amount of thermal expansion is also higher in the casing 1. is large, and the fixed ring and movable ring 3 are small. Therefore, casing 1
The center moves vertically due to thermal elongation.

However, the two flanges 6a of the casing 1.

6b upper surface 6c, 6d are two keys 118 of fixing ring 2
11b and is restrained in the vertical direction, the fixing ring 2 moves vertically by the same amount at the same time as the casing 1, and there is no relative change between the casing 1 and the fixing ring 2.

Furthermore, when the casing 1 is thermally expanded in the horizontal direction, the top key 12 of the fixing ring 2 is inserted into the groove 10 of the casing 1, so even if the casing 1 is thermally expanded in the horizontal direction, the casing 1 and the fixing ring have the same relative center position and do not change.

Moreover, since the fixed ring 2 is kept at a low temperature by cooling water, the center deviation of the fixed ring 2 reliably follows the deviation of the center due to thermal expansion of the casing 1, and the center of both is the same as that of the casing 1. Almost identical except for changes due to non-uniform thermal elongation.

Furthermore, the movable ring 3 is also kept at a low temperature by cooling water.
In addition, since the heat shield plate 15 blocks the heat from the casing 1, there is almost no thermal expansion.

Therefore, when the movable ring 3 is rotated in the circumferential direction by the drive unit 22 of the movable parts drive mechanism 5 to move the plurality of movable parts 26, the plurality of movable parts 26 cannot be moved by the same amount at the same time. can.

Next, according to the experimental results of the present invention, as shown in Figure 4, the amount of elongation of the casing from startup to 100% load operation is large, while the amount of thermal elongation of the fixed ring and movable ring is almost negligible. do not have.

Therefore, the casing during 100% load operation,
The difference in thermal elongation between the fixed ring and the movable ring is the maximum δ.

However, the fixed ring holds the casing so that its relative central position does not change, and the movable ring support mechanism supports the movable ring evenly from the inner circumference and holds the movable ring concentrically with respect to the casing. Good control accuracy can be obtained for moving parts.

Next, FIG. 5 is a diagram comparing the conventional method and the present invention with respect to the amount of deviation of the center between the casing and the movable ring, which determines the level of control accuracy. As already explained, the present invention has a movable ring whose inner circumference is evenly held by a movable ring support mechanism, and a fixed ring that is centerline supported by a casing and kept at a low temperature by cooling water, and is kept at a low temperature by cooling water. Therefore, compared to the conventional case, there is almost no eccentricity during the transition period from startup to 100% load.

〔Effect of the invention〕

According to the present invention, it is possible to minimize the misalignment between the centers of the casing and the movable ring from startup to 100% load, and simultaneously drive a plurality of movable parts by the same amount with high precision.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a variable control mechanism for a gas turbine which is an embodiment of the present invention, Fig. 2 is a perspective view showing a movable parts drive mechanism, Fig. 3 is a diagram showing a movable ring support mechanism, and Fig. 4 is a diagram showing a movable ring support mechanism. 5 is a diagram showing the amount of thermal elongation of the casing, fixed ring, and movable ring during load operation, and FIG. 5 is a diagram comparing the eccentricity of the center of the casing and the movable ring during load operation in the present invention and the conventional method. DESCRIPTION OF SYMBOLS 1... Casing, 2... Fixed ring, 3... Movable ring, 4... Movable ring support mechanism, 5... Movable part drive mechanism, 26... Movable part.

Claims (1)

[Claims] 1. It has a movable ring supported by a support mechanism located on the outer periphery of the casing, and rotation of the movable ring causes a plurality of movable parts of the gas turbine to be simultaneously operated by the same amount via a drive mechanism. In the variable control mechanism of the gas turbine,
Rotating a fixed ring located around the casing and concentrically with the casing and supported in a vertically and horizontally restrained state, and a movable ring supported by the fixed ring and located concentrically with the casing. A variable control mechanism for gas turbines equipped with a movable ring support mechanism that supports freely. 2. A plurality of flanges protruding horizontally outward are provided on the outer circumferential surface of the casing at horizontally opposing positions, and a plurality of flanges protruding horizontally inward at positions horizontally opposing the inner circumferential surface of the fixing ring on the upper surface of the plurality of flanges. A key groove is provided on the top of the outer peripheral surface of the casing, and the key on the top of the inner peripheral surface of the fixed casing is slidably vertically within the key groove. The variable control mechanism for a gas turbine according to claim 1, wherein the variable control mechanism is inserted into the gas turbine. 3. The variable control mechanism for a gas turbine according to claim 2, wherein the fixed ring is provided with a cooling mechanism. 4. The variable control mechanism for a gas turbine according to claim 2, wherein the movable ring is provided with a cooling mechanism.