JPH01193034A - Discharge diffuser of gas turbine - Google Patents

Abstract

PURPOSE:To prevent oscillations in the horizontal direction in a device where the horizontal flange of a discharge diffuser is fitted to a fitting member formed between horizontal flanges of a discharge casing by providing an oscillation preventing resilient member at the inner end of the horizontal flange. CONSTITUTION:A discharge diffuser 1 and a discharge casing supporting the diffuser 1 are respectively partitioned into two, and connected with flanges. Namely, they protrude inwards in the horizontal direction from the upper and lower ends 1u, 1s; 5u, 5s of the diffuser 1 and the casing 5, and connect the horizontal flanges 7u, 7s; 8u, 8s extending in the axial direction with a bolt/nut 9 in a face-to-face relation. In this case, the members in the vicinity of the inner ends of the horizontal flanges 7u, 7s are fitted into a fit member 10 between the flanges 8u, 8s, while an oscillation preventing resilient body 14 is arranged in the member 10 in order to restrain generation of oscillations applied to the diffuser 1.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application De) The present invention is an exhaust diffuser installed in the exhaust system of gas turbine equipment, in which vibration in the horizontal direction is prevented. Regarding the diffuser.

(Prior art) In gas turbine equipment, fuel is combusted in a combustor by the discharge air of an air compressor, and the combustion gas generated at that time is passed between the stator blades and rotor blades of each stage. Most of the thermal energy is converted into rotational energy of the turbine rotor, and the exhaust gas discharged from the final stage is discharged to the outside through an exhaust diffuser. This exhaust diffuser functions as a passage for exhaust gas, and
It is used as a means to change the flow direction of exhaust gas.

FIG. 3 shows a schematic configuration of the vicinity of an exhaust diffuser in gas turbine equipment, and the exhaust diffuser inner tube 1 and the exhaust diffuser outer tube 2 are each composed of a front portion 1a, 2a and a rear portion 1b, 2b. The front part 1a and the rear part 1b of the exhaust diffuser inner cylinder 1 and the front part 2a and the rear part 2b of the exhaust diffuser outer cylinder 2 are each provided with a flange connection 3.4 at the vertical portion, and are fixed with bolts.

Further, the exhaust casing 5 supporting the exhaust diffuser inner cylinder 1 is also horizontally arranged from the front part 5a and the rear part 5a, and is integrated by bolting flanges 6a and 6b.

The exhaust diffuser inner cylinder 1 and the exhaust diffuser outer cylinder 2, which are integrated with the front parts 1a and 2a and the rear parts 1b and 2b as described above, are each divided into two parts at the horizontal part and are joined by flanges. .

FIG. 4 shows the joint between the exhaust diffuser inner cylinder 1 and the exhaust casing 5, and shows the upper part 1u of the exhaust diffuser inner cylinder.
Horizontal flanges 7u and 7s, which protrude horizontally inward from the upper and lower end surfaces of the lower part 1s of the exhaust diffuser inner cylinder and extend along the axial direction, are joined face-to-face and integrated. Also,
Horizontal flanges 8u and 8s', which protrude horizontally inward from the upper and lower end surfaces of the upper part 5u and lower part 5s of the exhaust casing 5 and extend in the axial direction, are also joined face-to-face and connected by bolts and nuts 9.

A fitting part 10 is formed between the outer surfaces of the horizontal flanges 8u and 8s in a direction parallel to the axial direction of the gas turbine, and the vicinity of the inner ends of the horizontal flanges 7u and 7s are fitted and supported in the fitting part 9. has been done.

In FIG. 3, 11 indicates a turbine rotor, 12 indicates a rotor blade in the final stage of the turbine, and arrow 13 indicates the direction of flow of exhaust gas.

(Problem to be Solved by the Invention) In the conventional gas turbine exhaust diffuser described above, the horizontal flange of the exhaust diffuser inner cylinder is simply inserted into the joint formed between the horizontal flanges of the exhaust casing. Because of its structure, it can handle vertical forces, but it is weak against horizontal forces, and when a large horizontal force is applied, the outer surfaces of the horizontal flanges 7u and 7s and the upper and lower surfaces of the fitting part 10 There was a risk that slipping would occur between the two, causing the exhaust diffuser to vibrate in the horizontal direction, causing cracks in the exhaust diffuser and loosening of bolts and nuts on the flange portion 4, resulting in a serious accident.

The present invention has been made to solve the above problems,
An object of the present invention is to provide an exhaust diffuser for a gas turbine that can effectively suppress horizontal vibration of the exhaust diffuser.

[Structure of the Invention] (Means for Solving the Problems) The exhaust diffuser of the present invention is an exhaust diffuser for a gas turbine, in which a horizontal flange of the exhaust diffuser is fitted into a fitting portion formed between horizontal flanges of an exhaust casing. In the present invention, a vibration-preventing elastic body is provided between the bottom surface of the fitting portion and the inner end of the horizontal flange of the exhaust diffuser.

(Function) In the gas turbine exhaust diffuser of the present invention configured as described above, the vibration between the bottom surface of the fitting part of the exhaust casing and the inner end of the horizontal flange of the exhaust diffuser is The vibration-preventing elastic body placed in the gap acts to weaken the force applied to the exhaust diffuser, so its horizontal vibration is suppressed.

(Example) Next, the present invention will be explained in detail with reference to FIG.

In FIG. 1, the same parts as in FIGS. 3 and 4' are given the same reference numerals, and explanations of the overlapping parts will be omitted.

FIG. 1 shows an inner cylinder support portion of a gas turbine exhaust diffuser according to the present invention, and FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG.

As is clear from these figures, the gas turbine exhaust diffuser of the present invention has a vibration-preventing elastic body 1 in the fitting part 10.
4, and the other configurations are the same as the conventional one.

As the vibration-preventing elastic body 14, a plate spring is used that is wave-shaped along the length direction of the fitting portion 10, that is, in a direction parallel to the axial direction of the gas turbine.

In the device of the present invention having such a configuration, the leaf spring applies a reaction force to the horizontal excitation force due to its rigidity, so that movement of the exhaust diffuser is suppressed.

[Effects of the Invention] As described above, according to the gas turbine exhaust diffuser according to the present invention, since the vibration-preventing elastic body can suppress the movement of the exhaust diffuser in the water direction, cracks in the exhaust diffuser due to vibration can be suppressed. By tightening bolts and flanges, loosening of bolts can be suppressed, serious accidents caused by these can be prevented, and plant safety can be improved.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a portion of how the exhaust diffuser inner cylinder is attached to the exhaust casing, and FIG. 2 is a vertical cross-sectional view taken along line I-n in FIG. 1. Figure 3 is a schematic diagram of the exhaust diffuser part in a gas turbine;
FIG. 4 is a cross-sectional view showing a portion of how an exhaust diffuser inner cylinder is attached to an exhaust casing according to the prior art. 1... Exhaust diffuser inner cylinder 2... Exhaust diffuser outer cylinder 3.4... Vertical flange 5... Exhaust casing 7u, 7s, 8u, 8s. ...Horizontal flange 10
...Fitting part 14...°...Vibration prevention elastic body Agent Patent attorney Noriyuki Chika Ken Yudo Daishimaru Ken Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) In an exhaust diffuser for a gas turbine in which a horizontal flange of the exhaust diffuser is fitted into a fitting part formed between horizontal flanges of an exhaust casing, the bottom surface of the fitting part and the inner end of the horizontal flange of the exhaust diffuser An exhaust diffuser for a gas turbine, characterized in that a vibration-preventing elastic body is provided between the diffuser and the exhaust diffuser.