JPS5910741A - Ignition device for gas turbine - Google Patents

Abstract

PURPOSE:To prevent insulation resistance from being reduced by dewing in an ignition system provided with an ignition plug extending through a fuel chamber of a gas turbine, by providing a partition wall surrounding the ignition plug in the fuel chamber. CONSTITUTION:An ignition plug electrode 17 extending through a fuel chamber 20 is provided to be surrounded by an insulation rod 16. Outside a tubular inner wall 20a through which the insulation rod 16 extends is provided a partition wall 24 surrounding an ignition plug 7. By causing the tubular inner wall 20a not to contact fuel 12 is prevented air in the inside space 21 from dewing inside the tubular inner wall 20a.

Description

[Detailed description of the invention] The present invention relates to an ignition device for a gas turbine.

This is a schematic cross-sectional view of a first gas turbine combustor.
It flows into the inner cylinder 5 of the baking mold. The incoming air is sprayed with fuel 12 by the fuel nozzle 6, and is ignited by the spark plug 7 to start combustion. 6a is the injection hole of the nozzle 6. The combustion gas is 8 cylinders in the combustor inner cylinder. 5 to the transition piece 9ff:&\, flows into the turbine section 10 and does work, and is released into the atmosphere as exhaust gas 11. 13 is the output lead,] 4 is the ignition transformer, 15t: t is the power source. .

FIG. 2 is an enlarged sectional view of the vicinity of the fuel nozzle 6.

The ignition plug 7 is used during operation, and is supplied with high voltage from the ignition transformer via the output lead 13 to the spark plug 7 inside the combustor.
A high-voltage spark discharge is generated between the discharge generating part 18 of the electrode 17 protruding into the electrode 5 and the power receiving part 19 provided opposite to the discharge generating part 18 to perform an ignition action.

Above electrode 17! d It is wrapped in an insulating rod 16 and passes through the fuel chamber 6 of the fuel nozzle 6. FIG. 3 shows an enlarged detailed view of the portion where the spark plug electrode 17 described above is surrounded by the insulating iron 16 and penetrates into the fuel chamber 20.

At the location where the insulating rod 16 penetrates the fuel chamber 20, the fuel chamber 20 is formed with a tubular inner wall 20a for the insulating rod 16 to penetrate, and the electrode 17 and the insulating rod 16il-j surrounding the electrode 17, - A space 21 that is loosely fitted and inserted into the tubular wall 20a and communicated with the atmosphere is formed between the tubular inner wall 20a and the inner wall surface of the tubular inner wall 20a. Due to heat conduction, the temperature becomes considerably higher than the atmospheric temperature, and the fuel chamber 20 surrounding it
Due to the constant flow of fuel therein, the fuel flow 2 moves through the tubular inner wall 20a to cool the air in the space 21. Therefore, the relatively high temperature air in the space 21 comes into contact with the relatively low temperature tubular inner wall 20a and condenses on the inner surface of the tubular inner wall 20a to form water droplets 22.

When the dew condenses as described above, the insulating rod 16 swirls and the insulation resistance decreases, and when the gas turbine is stopped and then restarted, the high tortoise pressure creeping dielectric breakdown of the insulating rod 16 is avoided. There is a risk that the spark plug will not be able to start due to discharge not occurring at the tip of the spark plug.
= Shrink.

The present invention has been made in view of the above-mentioned circumstances, and eliminates the risk of the insulation resistance of the insulating iron being reduced due to dew condensation, thereby increasing the ignition reliability when starting a gas turbine, and improving the durability of the spark plug. The object of the present invention is to provide a gas turbine ignition device that can be used in a gas turbine.

In order to achieve the above object, the ignition device of the present invention has the following features:
The ignition device in which the entire spark plug penetrates the fuel chamber of a gas turbine is characterized in that a partition wall surrounding the spark plug is provided in the fuel chamber.

Next, an embodiment of the gas turbine ignition system of the present invention will be explained with reference to FIGS. 4 and 5. FIG. 4 1 is a sectional view of an example of the ignition device according to the present invention, and corresponds to FIG. 2 of the conventional ignition device.

Combustor outer cylinder 4, same outer cylinder 5, fuel nozzle 6, spark plug 7, fuel 12, insulating rod 16, electrode 17, discharge The generating section 18, the power receiving section 19, and the fuel chamber 20 are the same components as in the conventional device.

Also, the tubular inner wall 20a1 of the fuel chamber, which has the same drawing reference number as the enlarged sectional view (FIG. 3) of the conventional device, and the space 21 inside the tubular inner wall 1 have the same configuration as in the conventional device. . In this figure, the electrically related member f is omitted.

The arrangement of the present invention is particularly different from conventional devices in that a partition wall 24 is provided in the fuel chamber 20, facing and spaced apart from the outside of the tubular inner wall 20a, and largely surrounding the spark plug 7.

The fuel 12 flows through the partition wall 24 and is sprayed from the injection hole 6a. In this way, by preventing the tubular wall 20a that supports the insulating rod 16 of the spark plug 7 from coming into contact with the fuel 12, the core tubular wall 20a is less likely to be cooled by the fuel 12. Air in the space 21 is prevented from condensing on the inner surface of the tubular wall 20.

In this embodiment, an air compressor (main unit) is installed in a space formed inside the partition wall 24, specifically, in a cylindrical space 23 formed between the partition wall 24 and the tubular wall 20a. Not shown in the figure. A drain (126 is provided) which guides a part of the air 2 (not shown in the figure) to the space 23 of 10 dl'1 and communicates the space with the atmosphere. .

FIG. 5 shows the fuel chamber 20 (;, j Ui
Fig. 3 is an enlarged detailed view of the conventional ignition system, corresponding to Fig. 3; Discharge viewing point 2 compressed by air compressor
As the temperature rises due to adiabatic compression, the discharge airflow 2u flowing through the space 23 heats the chimney in the fuel chamber 20 through the partition wall 24 and heats the smoke in the space 21 through the tubular wall 20a. The air is kept warm and is cooled by the discharge airflow itself. Therefore, the 2P airflow Q flowing through the space forms water droplets 22 on the inner wall surface of the space 23.

The 9 air in the space 21 is a partition wall 2 provided by applying the present invention.
4 prevents heat exchange with the fuel 12, so it ends.
The risk of the insulating rod 16 getting wet 7 and deteriorating its insulating performance is significantly reduced. Furthermore, as in this embodiment, the airflow 2 having a higher temperature than the fuel in the fuel chamber is guided into the space 23 formed inside the partition wall 24, and the airflow 2 is heated between the spark plug 7 and the fuel 12. By interposing a fluid layer at a higher temperature than the above temperature, condensation in the space 21 can be more completely prevented. When the temperature of the air flow 2 is made higher than the temperature in the space 21, there is no possibility of formation of fins in the space 21.

If a drain hole 26 is provided as in this embodiment, water droplets 22 generated by condensation of the airflow 2 flowing through the space 23 are discharged from the drain hole. The function of the flow rate control orifice is to control the flow rate of the air flow 2 that flows through the space 23 and is discharged into the atmosphere by appropriately setting the shape and dimensions (minimum hole diameter) of this drain hole. This also prevents the high pressure and temperature nitrogen generated by the air compressor from being consumed more than necessary.

As explained above, the present invention provides an ignition device in which an ignition plug is provided by penetrating the fuel chamber of a gas turbine.
By providing a partition wall surrounding the spark plug in the fuel chamber described above, the insulating rod of the spark plug is prevented from having its insulation resistance reduced due to condensation, thereby increasing ignition reliability when starting the gas turbine. As a result, an excellent practical effect can be obtained in that the durability of the spark plug can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the vicinity of the combustor of the gas turbine, FIG. 2 is an enlarged sectional view of the vicinity of the ignition plug, and FIG. 3 is an enlarged sectional view of the vicinity of the fuel chamber. FIG. 4 is a sectional view of an embodiment of the gas turbine ignition device of the present invention, and FIG. 5 is an enlarged sectional view of the vicinity of the fuel chamber.

Claims (1)

[Scope of Claims] 1. An ignition device for a gas turbine in which an ignition plug is provided in direct communication with the fuel chamber of a gas turbine, characterized in that a partition wall surrounding the spark plug is provided in the fuel chamber. . 2. -3-, the partition wall described above allows a fluid having a higher temperature than the fuel in the fuel chamber to flow through a space formed inside the partition wall,
The ignition device for a gas starter or bottle according to claim 1, characterized in that the ignition device has a structure in which a layer of fluid having a higher temperature than the fuel is interposed between the spark plug and the fuel. 3. The gas turbine ignition device according to claim 2, wherein the partition wall has a drain hole provided in a space formed inside the partition wall.