JPS6143106Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air bypass structure in a gas turbine.

Generally, a gas turbine includes a casing in which a compressor, a combustor, and a turbine are installed in series in the flow direction. The exhaust gases of the turbine are exhausted to the atmosphere through an exhaust conduit.

An example of the combustor section of the conventional gas turbine described above is shown in FIG. In FIG. 1, air exiting compressor 101 enters combustor 102. The high-temperature gas combusted here flows into the turbine 104 through the transition piece 103. Here, 105 is an air bypass pipe 106, which is a bypass valve.

In the air bypass structure as described above, when bypass air is not flowing, there is no temperature difference between the bypass pipe roots 107 and 108.
No thermal stress is generated, but when bypass air is flowing, the base of the bypass pipe 107 is cooled by the bypass air, while the transition piece 108 is in a heated state due to the combustion gas flowing through it, so there is a gap between the two. It had the disadvantage of creating a temperature difference and generating thermal stress. Furthermore, depending on the gas flow condition within the transition piece, there is a drawback that a temperature difference may occur between the bases 107 and 109 of the bypass pipes.

The present invention eliminates the above drawbacks,
A heat shield pipe is installed inside the air bypass pipe to prevent the base of the bypass pipe from being overcooled even when bypass air is flowing, and to prevent temperature differences from occurring in the circumferential direction of the base of the bypass pipe. This is a characteristic feature.

The present invention can be widely applied to gas turbines and jet engines.

An embodiment of the present invention will be described with reference to FIG. This is similar to a conventional gas turbine in that the compressor, combustor, and turbine are installed in series in the turbine casing in the flow direction.

In the gas turbine as described above, the compressor 2
Air exiting 01 flows into combustor 202. The high-temperature gas burned in the combustor then flows into the turbine 204 through the transition piece 203.

At this time, when bypassing the air, the bypass air flows into the transition piece 203 through the bypass valve 205 and the bypass pipe 206, but at this time, a temperature difference and hence thermal stress are generated at the base of the bypass pipe.
The present invention installs a heat shield pipe 207 within the bypass pipe 206 to prevent this temperature difference. A heat shielding pipe of arbitrary length and material is selected depending on the temperature and flow rate of high-temperature combustion gas passing from the combustor 202 to the transition piece 203.

Since the present invention is constructed as described above, it achieves the following effects.

(1) Regardless of when bypass air is not flowing or when it is flowing, no temperature difference or thermal stress is generated between the base of the bypass pipe and the transition piece.

(2) No temperature difference or thermal stress occurs in the circumferential direction of the base of the bypass pipe.

(3) Although the structure is subject to thermal fatigue, this drawback can be avoided by using a heat shield tube.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a conventional gas turbine combustor section, and FIG. 2 is a schematic diagram showing a gas turbine combustor section according to the present invention. 101,202...Compressor, 102,202...
... Combustor, 103,203 ... Transition piece, 104,2
04...Turbine, 105,205...Air bypass pipe, 106,206...Bypass valve, 10
7,108,109...Bypass pipe base, 2
07...Heat shielding tube.

Claims (1)

[Scope of utility model registration request] An air bypass structure for a gas turbine, characterized in that an air bypass pipe is provided while guiding high temperature combustion gas from the combustor to the turbine, and a heat shielding pipe is provided inside the air bypass pipe.