JPH0351657Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a combustor for a gas turbine, and more particularly, to a bypass valve opening/closing device provided in the combustor.

BACKGROUND OF THE INVENTION A gas turbine is generally shown in a system diagram as shown in FIG. In other words, one shaft 1 has a compressor 2,
A turbine 3 and a load 4 are coupled together, and a number of combustors 5 (only one is shown in FIG. 3) are provided concentrically surrounding the shaft 1.
Air is taken into the compressor 2 from the air intake port 6, compressed, mixed with the fuel to be burned in the combustor 5 to produce combustion gas, and this combustion gas is introduced into the turbine 3 to power the turbine 3. Rotate. Note that 7 is a combustion gas exhaust port.

The conventional combustor 5 used in the above-mentioned turbine will be explained with reference to FIG. 4. 10 is a casing, 11 is a compressor diffuser, 12 is a combustor inner cylinder, 13 is a transition piece, 14 is a gas turbine side, 15 is a bypass elbow branched from the transition piece, 16 is a bypass air hole formed at the tip of the bypass elbow, 1
A bypass valve 7 is a butterfly valve provided in a bypass air hole, and a link mechanism 18 adjusts the opening and closing of the bypass valve.

In the above configuration, the combustion air (see arrow) that flows from the compressor diffuser 11 to the fuel supplied to the combustor inner cylinder 12 and flows into the combustor inner cylinder 12
After being combusted into high-temperature combustion gas, the gas is led to the gas turbine side 14 via the transition piece 13. Then, the gas turbine combustor is
In order to operate stably in the NOx combustion state, it is necessary to adjust the amount of air discharged from the compressor and allow it to flow into the combustor 5. Therefore, a part of the combustion air is caused to flow into the transition piece 13 from the bypass air hole 16 with a variable inflow amount provided with a bypass valve 17, via the bypass elbow 15, and at this time, the link mechanism 18
The bypass air hole is adjusted by operating the bypass valve 17. Each combustor 5 can be operated at one location.
A link mechanism 18 is attached to the casing 10 so that the amount of air can be adjusted by uniformly opening and closing a bypass valve 17 provided in a bypass elbow 15 of the casing.

However, the temperature of casing 10 is 250℃~300℃
The link mechanism 18 provided in the high-temperature casing 15 of the gas turbine was exposed to such high temperatures that the drive section became stuck due to thermal deformation, making it difficult to adjust the amount of air necessary for low NOx.

Problems to be Solved by the Invention The present invention solves the drawbacks of the above-mentioned conventional techniques. That is, by opening and closing the bypass valves provided in the transition piece of each combustor uniformly with one operation,
This is an attempt to solve the problem that the link mechanism that adjusts the amount of air is thermally deformed, causing the drive section to become stuck.

Means for Solving the Problems In order to solve the above problems, when a link mechanism for opening and closing the bypass valve is provided in the high temperature (250° to 300°C) casing of a gas turbine, it is necessary to To prevent this, technical measures are taken in which a separate air source for cooling the linkage, for example an air blower supplying air from factory air, is provided adjacent to the linkage.

Effect By adopting the above technical means, the drive part of the bypass valve opening/closing link mechanism is cooled, and by keeping the metal temperature of the drive part constant, stagnation due to thermal deformation is prevented, resulting in low NOx combustion. This allows the necessary amount of air to be adjusted.

Embodiment Hereinafter, a gas turbine combustor of the present invention will be described with reference to an embodiment shown in FIGS. 1 and 2 (A-A arrow view in FIG. 1). In addition, in Figure 1, the fourth
The same parts as those in the figures are given the same reference numerals, and explanations of those parts will be omitted.

The link mechanism 18 includes a valve shaft 19 extending from the bypass valve 17 and a rod 20 connected to the valve shaft 19. The drive unit that moves this link mechanism 18 is connected to pedestals 21 provided at six locations on the circumference of the gas turbine casing 10, and an inner side attached to the pedestal 21 on the circumference of the casing 10 with a center pin 22 on the outside of the pedestal 21. A double ring system consisting of a ring 23 and an outer ring 24 fitted around the outer periphery of the inner ring 23 is adopted.

Further, an air blowing device consisting of a circular ring shell 25 is provided on both sides of the inner ring 23 at an intermediate portion between the casing 10 and the inner ring 23.

The gas turbine combustor of the present invention is configured as described above, and the discharge air that exits the compressor diffuser flows into the combustor inner cylinder 12, but a part of it flows through the bypass elbow provided in the transition piece 13. The air flows into the transition piece 13 from the bypass air holes 16 of 15 through the bypass elbow 15, merges with the combustion gas flow inside the transition piece 13, and is guided to the turbine 14.

By rotating the outer ring 24, which is the driving part of the link mechanism 18, on the circumference of the inner ring 23, the power is transmitted to the bypass valve 17, which is a butterfly valve, via the rod 20 and the valve shaft 19, and the bypass Air holes 16 are adjusted.

In addition, for example, factory air 02 is blown from the circular ring shell 25 to the driving part of the link mechanism to keep the metal temperature of the inner ring 23 and the outer ring 24, which are double ring parts, constant.

Effects of the Invention As described above, the present invention achieves the following special effects by virtue of the above-described configuration.

(1) By providing an air blowing device adjacent to the drive part of the link mechanism, it is possible to prevent the double ring part, which is the drive part of the variable bypass valve mechanism installed in the high-temperature casing of the gas turbine, from becoming stuck due to thermal deformation. The structure allows for easy adjustment of the amount of air required for low NOx combustion.

(2) The entire gas turbine is installed indoors due to noise, etc. At that time, due to natural convection in the indoor air, there is a temperature difference of about 30°C between the ceiling and floor sides, which causes the double ring may be distorted asymmetrically between the top and bottom, but the air blowing device can effectively work against the above-mentioned thermal deformation.

The present invention is applicable not only to gas turbines but also to jet engines, and can be modified and implemented as appropriate without departing from the spirit of the invention.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional schematic diagram showing an embodiment of the gas turbine combustor of the present invention, FIG. 2 is a view taken along arrow A-A in FIG. 1, and FIG. 3 is a general gas turbine combustor. FIG. 4 is a schematic diagram of a conventional gas turbine combustor. 1...Shaft, 2...Compressor, 3...Turbine, 4
...Load, 5...Combustor, 6...Air installation port, 7
... Combustion gas discharge port, 10 ... Casing, 11
...Compressor differential user, 12...Combustor inner cylinder,
13... Transition piece, 14... Turbine side, 15... Bypass elbow, 16... Bypass air hole, 17...
... Butterfly valve (bypass valve), 18 ... Link mechanism, 19 ... Valve shaft, 20 ... Rod, 21 ... Pedestal, 22 ... Center pin, 23 ... Inner ring, 24 ... Outer ring, 25 ... ...Circle shell, 01
...Discharged air, 02...Factory air.

Claims (1)

[Scope of utility model registration request] A large number of combustors each consisting of an inner cylinder and a transition piece are arranged around the turbine shaft inside the casing, and fuel and compressed air are mixed and combusted in the inner cylinder, and the combustion gas is supplied to the gas turbine through the transition piece. In the combustor, an air hole with a bypass valve for adjusting and inflowing bypass air is formed in a bypass elbow branched from the transition piece, and a link mechanism for opening and closing the bypass valve that simultaneously operates the bypass valve is provided in the casing. A bypass valve opening/closing device for a combustor, the bypass valve opening/closing device for a combustor comprising: an air blowing device adjacent to the link mechanism for cooling the link mechanism;