JPH04279733A - Ignition method of gas turbine - Google Patents

Abstract

PURPOSE:To pass the sparking part of an ignition plug to an optimum ignition position without fail regardless of the variation of the ignition angle of a sprayed fuel, and to carry out the ignition of the sprayed fuel securely constantly, by reciprocating the ignition plug in a preset stroke for a specific period when the sprayed fuel is ignited. CONSTITUTION:To the manual setting member 10 of a controller 8, the temperature of fuel, the character of fuel, and some other specific ignition plug stroke instructions, and a set signal corresponding to the stroke center are input. And a current amplified in a current generator 11 is fed to an electropneumatic converter 16. And a compressed air reduced to a specific pressure by a regulator 17 is led in to an air cylinder 19 installed on the outer tube 1 of a combustor through the electropneumatic converter 16, a three-port electromagnetic change- over valve 18, and an orifice 25. And the three-port electromagnetic changeover valve 18 is operated for a specific period by a timer 24, and opened and closed depending on the ignition plug stroke instruction from the current generator 11 in the period. Consequently, the ignition plug connected to arms 22a and 22b is reciprocated corresponding to the up and down movement of a piston 20.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition method for a spark plug used in a liquid fuel-fired gas turbine, and more particularly to an ignition method for improving ignition reliability.

0002

[Prior Art] A combustor that injects liquid fuel into compressed air sent from a gas turbine compressor and burns it, and sends the fuel gas to the turbine, is equipped with an ignition valve to ignite the fuel when the gas turbine is operating. An igniter is provided for inserting the plug into the combustor. In addition, the types of ignition devices include the spark ignition method, which uses a high-voltage current to spark a spark in the gap between the spark plugs and ignites the atomized fuel, and a thick coiled nichrome wire or silicon carbide rod that is charged, red-hot, and becomes the atomized fuel. There are two types of ignition methods: the glow plug method, in which ignition is caused by contact, and the torch ignition method, in which a torch is inserted into the inner cylinder of the combustor to ignite it. Of these, the spark ignition method is the most widely used because of its simple structure.

Next, an example of a conventional ignition device for a fuel unit of a liquid fuel-fired gas turbine will be explained with reference to FIG.

In the figure, 1 is an outer cylinder, 2 is an inner cylinder disposed within the outer cylinder 1 and has a plurality of air holes 3, 4 is a fuel injection nozzle, 5 is a spark plug 6, a linear differential transformer 7, etc. It is an ignition device consisting of. 8 is a controller and a voltage/current converter 9
, a manual setting section 10, and a current generating section 11 which is an electrical signal output section. 12 is a rectifier arranged to connect the differential transformer 7 and the voltage-current converter 9 of the controller 8; 13 is a thermocouple temperature detector provided at an appropriate position to detect the liquid fuel temperature; It is connected to the voltage-current converter 9 of the controller 8 via the amplifier 14. Further, the current generating section 11 of the controller 8 is connected to an electro-pneumatic converter 16 to which a compressed air pipe 15 is connected. A regulator 17 is provided on the upstream side of the compressed air pipe 15, and the downstream side is connected to an air cylinder 19 via a 3-port electromagnetic switching valve 18, forming a closed loop circuit as shown.

Next, the operation of the gas turbine including the ignition device 5 will be explained. To start the gas turbine and ignite the fuel, the temperature of the liquid fuel is first detected by the thermocouple temperature detector 13, and the detected voltage signal is amplified by the amplifier 14 and sent to the controller 8. Voltage current converter 9
is input to. The converted current is corrected to a current value corresponding to the fuel used in the manual setting section 10, which is set in advance according to the relationship between the temperature of the liquid fuel used and the injection angle θ, and the amplified current is output from the current generation section 11. It is sent to the electro-pneumatic converter 16.

Compressed air for the air cylinder, which is set at a predetermined pressure by a regulator 17, is introduced into the electro-pneumatic converter 16, and this compressed air is adjusted to a pressure corresponding to the input current value. The pressure is reduced at , and the air enters the air cylinder 19 via the 3-port electromagnetic switching valve 18 . The piston 20, the ignition plug 6, and the rod 21 of the linear differential transformer 7 are connected by arms 22a, 22b, and 22c so as to reciprocate as one body, so that the spark portion 23 of the ignition plug 6 moves in accordance with the movement of the piston 20. is inserted into the inner cylinder 2, and the amount of movement thereof is detected by the differential transformer 7 as the amount of voltage displacement.

Note that since the current generated by the thermocouple temperature detector 13 is direct current and the current generated by the differential transformer 7 is alternating current, the current generated by the differential transformer 7 is converted into alternating current by the rectifier 12 is converted into direct current and fed back to the controller 8. The current value of the manual setting unit 10 is corrected according to the fed-back current value, and the spark unit 23 is controlled to be accurately positioned on the fuel injection angle θ plane.

According to the above-described ignition method, the heat transfer thermometer 13
By detecting the liquid fuel temperature and controlling it by the controller 8, the spark portion 24 of the ignition plug is moved to the optimum ignition position on the fuel injection angle θ plane, thereby reducing ignition failure troubles.

[0009]

In the conventional device described above, the temperature of the liquid fuel is detected by the heat transfer thermometer 13, and the spark plug 2 of the ignition plug is placed at a preset position according to the detected temperature.
It is ignited after moving 4. However, the fuel spray angle changes not only depending on the temperature of the liquid fuel but also on the density and temperature of the gas turbine intake air, the properties of the fuel, and the like. There is a problem in that an extremely complex control device is required to optimally control the spark plug position as a function of these other multiple parameters.

The present invention has been made to solve the problems of the prior art described above, and provides an ignition method for a gas turbine that can reliably ignite regardless of the temperature and properties of the fuel or the density and temperature of the intake air. The purpose is to provide.

[0011]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a gas pump that is inserted into a combustor by an air cylinder and has an ignition plug for igniting atomized fuel injected from a fuel injection nozzle. In the turbine ignition method, the ignition plug is reciprocated with a preset stroke for a certain period of time when igniting the atomized fuel.

0012

[Operation] The injection angle of the atomized fuel injected from the fuel injection nozzle varies depending on the temperature and properties of the fuel or the density and temperature of the intake air, but since the ignition plug reciprocates with a preset stroke for a certain period of time, the ignition plug The spark part always passes through the optimum ignition position.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to the drawings. FIG. 1 is a diagram illustrating an embodiment of the gas turbine ignition method of the present invention, and the components other than those shown in FIG. 1 are constructed in the same manner as the conventional example shown in FIG. 3. Further, in FIG. 1, 24 is a timer connected to the current generator 11 and the 3-port electromagnetic switching valve 18, and 25 is an orifice inserted in the piping connecting the 3-port electromagnetic switching valve 18 and the air cylinder 19. be.

In the above configuration, the manual setting unit 10 of the controller 8 has an ignition plug stroke command that roughly takes into consideration the temperature and properties of the fuel as well as the density and temperature of the intake air, as in the conventional example, and a command that is set at the center of the stroke. A corresponding setting signal is input, and the current amplified by the current generator 11 is sent to the electropneumatic converter 16. The compressed air reduced to a predetermined pressure by the regulator 17 passes through the electro-pneumatic converter 16, the 3-port electromagnetic switching valve 18, and the orifice 25 into the outer cylinder 1 of the combustor.
The air flows into the air cylinder 19 attached to the air cylinder 19. The 3-port electromagnetic switching valve 18 is operated for a certain period of time by a timer 24, during which it opens and closes in response to the spark plug stroke command from the current generator 11, and opens and closes the arms 22a and 22b in response to the upward and downward movement of the piston 20. reciprocates the spark plug connected to the The orifice 25 restricts the amount of air flowing into or out of the cylinder 19 and functions as a piston deceleration mechanism.

FIG. 2 is a block diagram showing another embodiment of the gas turbine ignition method of the present invention. This embodiment also has the same structure as the conventional example shown in FIG. 3 except for the parts shown in FIG.

In FIG. 2, the same elements as those in FIG. 3 are given the same reference numerals, and redundant explanations will be omitted. In Figure 2, 19
A is a pedestal extending laterally from the top of the air cylinder 19. An electric motor 26 is attached to this pedestal 19a, and a timer is connected between the electric motor 26 and the current generating section 11. 24 are connected. A cam 28 is fixed to the tip of the rotating shaft 27 of the electric motor 26. A lever 29 is fixed to the upper end of the piston rod of the piston 20 with a nut 30 or the like, and a roller 32 is attached to the tip of the lever 29 in contact with the cam 28.

In the above configuration, the electric motor 26 is operated for a certain period of time by the timer 24 and rotates in response to a spark plug stroke command from the current generating unit 11. When the electric motor 26 rotates, a cam 28 fixed to the tip of the rotating shaft 27 rotates, and the rotation of the cam 28 causes the lever 29 to reciprocate via the roller 31. This reciprocating movement causes the ignition plug to reciprocate via the arms 23a and 23b.

The reciprocating movement of the spark plug according to the configuration shown in FIGS. 1 and 2 ensures reliable ignition of the atomized fuel injected from the fuel injection nozzle. The cycle of the reciprocating movement of the ignition plug is about 5 seconds, and after the ignition is completed, the ignition plug moves to the outside of the inner cylinder as in the conventional example.

[0019]

As described above, according to the present invention, since the ignition plug is reciprocated with a preset stroke for a certain period of time when igniting the sprayed fuel, the sprayed fuel injected from the fuel injection nozzle can be reliably ignited. be exposed.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of main parts showing an embodiment of the gas turbine ignition method of the present invention.

FIG. 2 is a configuration diagram of main parts showing another embodiment of the gas turbine ignition method of the present invention.

FIG. 3 is a configuration diagram showing an example of a conventional gas turbine ignition device.

[Explanation of symbols]

8 Controller 9 Voltage current conversion section 10 Manual setting section 11 Current generation section 16 Electro-pneumatic converter 18 3 port solenoid switching valve 19 Air cylinder 20 Piston 24 Timer 25 Orifice 26 Electric motor 27 Rotation axis 28 Cam 29 Lever 31 Roller

Claims (1)

[Claims] Claim 1: Inserted into a combustor by an air cylinder,
A method for igniting a gas turbine having an ignition plug for igniting atomized fuel injected from a fuel injection nozzle, characterized in that when igniting the atomized fuel, the ignition plug is reciprocated at a preset stroke for a certain period of time. How to ignite a turbine.