JPH10121986A - Gas turbine and ignition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To guarantee stable ignition by arranging an ignition device on a combustor which a fuel arrival time is latest or a combustor which a fuel injection start time is latest, in a gas turbine provided with a plurality of gas turbine combustors. SOLUTION: A gas turbine is formed in such a constitution that, for example, 14 pieces of gas turbine combustors 1 to 14 are formed on a concentric circle around a turbine rotor, and pigtail pipes 26, 27 are arranged corresponding to each of combustors 1 to 14. One ends of pigtail pipes 26, 27 are connected to a fuel injection nozzle, and the other ends are connected to manifold pipes 15, 19. One end of fuel base pipes 16, 20 are connected to lower parts of the manifold pipes 15, 19. In such a gas turbine, the combustor 14 is positioned opposing to a connecting part of the base pipe 16 for supplying fuel 25 into the manifold 15, and is farthest in the manifold pipe, its fuel spray time thereof is latest, and that of the combustor 13 is latest subsequently thereto. Therefore, ignition plugs 23 are arranged on the combustors 13, 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine having a plurality of gas turbine combustors and a method for igniting the same, and more particularly, to a gas turbine for supplying fuel to each gas turbine combustor through a manifold pipe and its ignition. About the method.

[0002]

2. Description of the Related Art Conventionally, in a gas turbine that supplies fuel to each gas turbine combustor through a manifold pipe, an ignition device is provided in a gas turbine combustor near a portion where fuel is introduced into the manifold pipe, and a fuel supply command is issued. Almost simultaneously, an ignition command is output to the ignition plug, and the gas turbine combustor that has reached the fuel ignites.

[0003]

In the above prior art,
In a gas turbine combustor or the like having the slowest fuel arrival time, the combustion gas propagates before the fuel arrives, so that stable ignition could not be performed, and the fuel might not be ignited.

An object of the present invention is to provide a gas turbine that stably ignites and a method of igniting the same.

[0005]

In order to achieve the above object, a gas turbine according to the present invention comprises a gas turbine combustor having a slowest fuel arrival time or a fuel injection start time among a plurality of gas turbine combustors. The ignition device is installed in the gas turbine combustor with the slowest time.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described with reference to the drawings.

FIG. 1 is a front view of a gas turbine according to a first embodiment of the present invention as viewed from a compressor side. FIG. 2 is a sectional view of a manifold tube according to the first embodiment of the gas turbine of the present invention. FIG. 3 is a side sectional view of a gas turbine combustor according to the first embodiment of the gas turbine of the present invention. FIG. 4 shows a gas turbine combustor according to a first embodiment of the gas turbine combustor of the present invention. In the figure,
14 is a gas turbine combustor, 15 and 19 are annular manifold pipes through which fuel flows, 16 and 20 are fuel mother pipes through which fuel flows, and 17 and 21 are control valves that control the flow rate of fuel.
Reference numerals 8 and 22 denote shut-off valves for shutting off fuel, 23 an ignition plug (spark plug) for igniting the fuel, 24 a flame detector for detecting the presence of a combustion flame, 25 a fuel, and 26 and 27 a pigtail pipe through which the fuel flows. , 28 are a casing for fixing the gas turbine combustor, 29 is a partition for spatially shutting off the inside of the manifold tube 15, 30 is a compressor for compressing the atmosphere, 31
Is the air compressed by the compressor 30, 32 and 33 are fuel injection nozzles for injecting fuel, 34 is the fuel 25 and air 31
, A premixing chamber for preliminarily mixing and 35, a flame stabilizer, 36, 37
Is a cylindrical liner, 38 is a transition piece, 39 is a diffusion combustion flame obtained by burning fuel 25 and air 31 while mixing, 40
Represents a premixed combustion flame obtained by burning a premixed gas obtained by previously mixing the fuel 25 and the air 31, and 41 represents a diffusion combustion flame 39
Alternatively, a combustion gas obtained from the premixed combustion flame 40, a turbine 42 rotated by the combustion gas 41, and a transmission tube 43 for transmitting the combustion gas 41 obtained from the diffusion combustion flame 39 to an adjacent gas turbine combustor.

In the first embodiment of the gas turbine of the present invention, a compressor 30 for compressing the atmosphere, and air 31 and fuel 25 compressed by the compressor 30 are mixed and burned to generate a combustion gas 41. Gas turbine combustors 1 to 14, a turbine 42 rotated by combustion gas 41, and a generator for generating electricity. The compressor rotor and the turbine rotor are configured as a single shaft and connected to the generator. . Then, 14 gas turbine combustors 1 to 14 are formed concentrically around the turbine rotor. Pigtail tubes 26 and 27 are provided corresponding to each of the gas turbine combustors 1 to 14.
One end of the pigtail tube 26 is connected to a plurality of fuel injection nozzles 32 provided concentrically, and the other end of the pigtail tube 26 is connected to the manifold tube 15. Also, the fuel mother pipe 1
One end of 6 is connected to the lower part of the manifold pipe 15 (between the connection of the pigtail pipe 26 of the gas turbine combustor 6 and the connection of the pigtail pipe 26 of the gas turbine combustor 7). The other end of the fuel mother pipe 16 is connected to fuel supply means for supplying the fuel 25. A control valve 17 is provided in the fuel mother pipe 16,
The shut-off valve 18 is formed. On the other hand, one end of the pigtail pipe 27 is connected to a plurality of fuel injection nozzles 33 provided concentrically, and the other end of the pigtail pipe 27 is connected to the manifold pipe 19. Also, one end of the fuel mother pipe 20 is connected to the lower part of the manifold pipe 19 (the connection part of the pigtail pipe 27 of the gas turbine combustor 6 and the pigtail pipe 2 of the gas turbine combustor 7).
7 connection). The other end of the fuel mother pipe 20 is connected to fuel supply means for supplying the fuel 25. A control valve 21 and a shutoff valve 22 are formed in the fuel mother pipe 20.

FIG. 5 shows the fuel arrival delay time of each gas turbine combustor based on the gas turbine combustor 6. However, this is the case where the partition 29 is not provided in the manifold tube 15. According to FIG. 5, the gas turbine combustor 14
It can be seen that the fuel arrival time of the gas turbine combustor 13 is the longest, and the fuel arrival time of the gas turbine combustor 13 is the second. This is because the connecting portion of the pigtail tube 26 of the gas turbine combustor 13 and the connecting portion of the pigtail tube 26 of the gas turbine combustor 14 are opposed to the connecting portion of the fuel mother tube 16 that supplies the fuel 25 to the manifold tube 15. This is considered to be due to the longest distance on the manifold tube. Therefore, in the first embodiment of the gas turbine of the present invention, the ignition plug 23 is provided in the gas turbine combustors 13 and 14 in which the fuel arrival time is short. FIG. 6 is a side sectional view of a gas turbine combustor having an ignition plug. The spark plug 23 is formed such that the spark portion at the tip of the spark plug 23 is located near the tip of the fuel injection nozzle 32 in the combustion chamber in the liner 36. Further, a partition 29 is formed so as to fill a space between the connection portion of the pigtail tube 26 of the gas turbine combustor 13 of the manifold tube 15 and the connection portion of the pigtail tube 26 of the gas turbine combustor 14, and the inside of the pigtail tube 26 is formed. Spatially cut off.

Further, the drain in the gas turbine combustor enters the detection portion at the tip of the flame detector 24, and the flame detector 2
Considering that the reliability of the flame detector 24 decreases, the flame detector 24
The flame detector 24 is formed such that the surface of the detection unit at the tip of the frame is below the horizontal. Therefore, in the first embodiment of the gas turbine of the present invention, among the gas turbine combustors 1-4, 10-14 located above the position slightly below the center axis of the turbine rotor, the ignition plug The flame detector 24 is provided in the gas turbine combustors 3 and 4 which are far from the gas turbine combustors 13 and 14 having the above. FIG. 7 shows a side sectional view of a gas turbine combustor having a flame detector.
The flame detector 2 is positioned such that the detector at the tip of the flame detector 24 is located near the tip of the fuel injection nozzle 32 in the combustion chamber.
4 is formed.

A first embodiment of the gas turbine ignition method according to the present invention will be described below.

FIG. 8 shows a first embodiment of a gas turbine ignition method according to the present invention.

The air 31 compressed by the compressor 30 is
It flows into the combustion chamber in the liner 36 or the combustion chamber in the liner 37. Upon receiving an ignition command for the gas turbine combustor, the spark plug 23 performs a spark operation. On the other hand, in response to the ignition command of the gas turbine combustor, the control valve 17 opens from a fully closed state to a predetermined opening degree, and thereafter, a shutoff valve 18 provided upstream.
However, the opening operation is performed from the fully closed state to the fully open state, and fuel flows through the fuel mother pipe 16. Here, the time from the ignition command to the start of the opening operation of the shut-off valve 18 is approximately 2 seconds from the actual performance of the actual machine. And the manifold pipe 15, the pigtail pipe 2
6, the fuel 25 is injected into the combustion chamber in the liner 36 through the fuel injection nozzle 32. Then, when the fuel-air ratio, which is the ratio of fuel to air, becomes equal to or higher than the fuel-air ratio required for ignition, a diffusion combustion flame 39 is formed in the gas turbine combustor 13 or the gas turbine combustor 14. Then, the combustion gas 41 propagates to the adjacent gas turbine combustor through the propagation pipe 43, and a diffusion combustion flame 39 is formed in the combustion chamber in the liner 36 of the adjacent gas turbine combustor. Such flame propagation is performed sequentially, and a diffusion combustion flame 39 is formed in all of the 14 gas turbine combustors.

When the load on the turbine 42 is 10
When the load reaches a predetermined load lower than 0% load (for example, 40% of the load at the time of rated operation), the control valve 21 opens from a fully closed state to a predetermined opening degree, and thereafter, a shutoff provided upstream. The valve 22 opens from the fully closed state to the fully open state, and fuel flows through the fuel mother pipe 20. And the manifold tube 19,
The fuel 25 is jetted into the premixing chamber 34 through the pigtail tube 27 and the fuel injection nozzle 33 and mixed with the air 31 to form a premixed air. A vortex of the premixed gas is formed downstream of the flame stabilizer 35 (a combustion chamber in the liner 37), and the combustion gas obtained by the diffusion combustion flame 39 propagates in the vortex of the premixed gas. A premixed combustion flame 40 is formed.

Diffusion combustion flame 39 or premixed combustion flame 4
The combustion gas 41 obtained in Step 0 flows into the turbine 42 through the transition piece 38, and the turbine 42 rotates.

In the rated operation in which the turbine 42 is fully loaded, the control valves 17 and 21 and the shut-off valves 18 and 2 are operated.
2 is fully open.

According to the gas turbine and the method for igniting the same according to the present invention, the non-ignition can be prevented by providing the first spark plug in the gas turbine combustor having the slowest fuel arrival time. Further, by providing the second spark plug also in the gas turbine combustor whose fuel arrival time is the second slowest, ignition can be performed even when the first spark plug does not spark. Also, the pigtail pipes of the two gas turbine combustors, which are the longest on the manifold pipe, are connected to the connection of the fuel mother pipe that supplies fuel to the manifold pipe that supplies fuel to the fuel ejection nozzle for diffusion combustion. By having a partition between the connections, the gas turbine combustor with the slowest fuel arrival time can be identified. In addition, the partition,
In order to fill the manifold between the pigtail connections of the two gas turbine combustors, the fuel is supplied in the manifold between the connection of the pigtails of the two gas turbine combustors. It is possible to suppress the occurrence of an air pool, suppress the fluctuation of the fuel flow rate supplied to the two gas turbine combustors caused by the fluctuation of the air pool, and improve the reliability of ignition. FIG.
FIG. 3 shows the delay in the arrival of combustion in the gas turbine combustors 1, 13, and 14 and the fluctuation of the fuel concentration based on the gas turbine combustor 6. FIG. If there is no partition, the fuel concentration may fluctuate and the ignition may not occur.

FIG. 10 is a front view of a gas turbine according to a second embodiment of the present invention as viewed from the compressor side. In the figure, 4
Reference numeral 4 denotes a manifold tube through which fuel flows. Note that the same reference numerals as those in the first embodiment denote the same components as those in the first embodiment.

In the second embodiment of the gas turbine of the present invention, the connection between the connecting portion of the pigtail tube 26 of the gas turbine combustor 13 of the manifold tube 44 and the connecting portion of the pigtail tube 26 of the gas turbine combustor 14 is provided. , Apparently cut,
The pigtail tube 26 is spatially shut off.

FIG. 11 is a front view of a third embodiment of the gas turbine according to the present invention as viewed from the compressor side. In the figure, the same reference numerals as in the first embodiment denote the same components as in the first embodiment.

In the third embodiment of the gas turbine according to the present invention, the fuel mother pipe 16 and the manifold pipe 45 are connected to the upper part of the manifold pipe 45 (the connection between the pigtail pipe 26 of the gas turbine combustor 13 and the gas turbine). (Between the connection portion of the pigtail tube 26 of the combustor 14). On the other hand, the fuel pipe 20 and the manifold pipe 46 are connected to the manifold pipe 4.
6 (pigtail tube 2 of gas turbine combustor 13)
7 and the pigtail tube 2 of the gas turbine combustor 14
7 connection portion). Further, the gas turbine combustor 6, which is located opposite to the connection portion of the fuel mother pipe 16 that supplies the fuel 25 to the manifold pipe 45, is considered to be the longest on the manifold pipe, and is considered to have a long fuel arrival time. 7, an ignition plug 23 is provided. Furthermore, the gas turbine combustors 1, 1 which are far from the gas turbine combustors 6, 7 having the spark plugs 23 and are considered to have slow flame propagation.
3 and 14 are provided with a flame detector 24.

FIG. 12 shows a second embodiment of the gas turbine ignition method according to the present invention.

In the second embodiment of the gas turbine ignition method according to the present invention, the control valve 17 opens from a fully closed state to a predetermined opening degree in response to an ignition command for the gas turbine combustor. (After 2 seconds), the shutoff valve 18 provided upstream is opened from the fully closed state to the fully open state, and fuel flows through the fuel mother pipe 16. The fuel 25 is injected into the combustion chamber in the liner 36 through the manifold pipe 15, the pigtail pipe 26, and the fuel injection nozzle 32. Thereafter, the spark plug 23 performs a spark operation. Here, the time from the start of the opening operation of the shut-off valve 18 to the time when the fuel injection nozzle 32 injects the fuel 25 is approximately 3 to 4 seconds from the actual performance of the actual machine. Therefore, ignition plug 2
3 sets the time for starting the spark operation 5 to 6 seconds after receiving the ignition command.

FIG. 12 shows a third embodiment of the ignition method for a gas turbine according to the present invention.

In the third embodiment of the method for igniting a gas turbine according to the present invention, the ignition plug 23 performs a spark operation in response to an ignition command for the gas turbine combustor. On the other hand, in response to the ignition command of the gas turbine combustor, the control valve 17 opens from the fully closed state to a predetermined opening, and thereafter (after 2 seconds), the shutoff valve 18 provided upstream is changed from the fully closed state to the open state. Predetermined opening (opening corresponding to fuel flow rate at which gas turbine combustor does not ignite)
And the fuel flows into the fuel mother pipe 16. The fuel 25 is injected into the combustion chamber in the liner 36 through the manifold pipe 15, the pigtail pipe 26, and the fuel injection nozzle 32.
Thereafter, the shutoff valve 18 opens from a predetermined opening degree to a fully opened state. Here, the time from the start of the opening operation of the shut-off valve 18 from the fully closed state to the time when the fuel injection nozzle 32 injects the fuel 25 is approximately 3 to 4 seconds from the actual performance of the actual machine.
Therefore, the time when the shut-off valve 18 starts the opening operation from the predetermined opening degree to the fully opened state is set 5 to 6 seconds after receiving the ignition command. The relationship between the predetermined opening degree of the shutoff valve 18 and the holding time thereof is determined by the fuel mother pipe 16, the manifold pipe 15,
It is determined by the volume of the pigtail tube 26 and the fuel injection nozzle 32.

According to the second embodiment and the third embodiment of the gas turbine ignition method of the present invention, after the fuel is filled in the fuel mother pipe, the manifold pipe, the pigtail pipe, and the fuel injection nozzle. In addition, since the spark plug is sparked, unignition can be prevented, and ignition reliability can be further improved.

[0027]

According to the present invention, an ignition device is provided in a gas turbine combustor having the slowest fuel arrival time or a gas turbine combustor having the latest fuel injection start time among a plurality of gas turbine combustors. Therefore, the fuel is ignited after the fuel reaches all the gas turbine combustors, and the unstable fluctuation of the fuel flow rate when fuel is supplied to the gas turbine combustors can be suppressed, and the ignition reliability of the gas turbine combustors can be reduced. Can be improved.

[Brief description of the drawings]

FIG. 1 is a first embodiment of a gas turbine according to the present invention.

FIG. 2 is a first embodiment of a gas turbine according to the present invention.

FIG. 3 is a first embodiment of a gas turbine according to the present invention.

FIG. 4 is a gas turbine combustor according to a first embodiment of the gas turbine of the present invention.

FIG. 5 is a fuel arrival delay time of each gas turbine combustor based on the gas turbine combustor 6;

FIG. 6 is a gas turbine combustor according to a first embodiment of the gas turbine of the present invention.

FIG. 7 is a gas turbine combustor according to a first embodiment of the gas turbine of the present invention.

FIG. 8 shows a delay in the arrival of combustion and a change in fuel concentration in the gas turbine combustors 1, 13, and 14 based on the gas turbine combustor 6.

FIG. 9 shows a first embodiment of a gas turbine ignition method according to the present invention.

FIG. 10 shows a second embodiment of the gas turbine of the present invention.

FIG. 11 shows a third embodiment of the gas turbine of the present invention.

FIG. 12 shows a second embodiment of the gas turbine ignition method of the present invention.

FIG. 13 is a third embodiment of the gas turbine ignition method according to the present invention.

[Explanation of symbols]

1-14: Gas turbine combustor, 15, 19, 44, 4
5, 46: Manifold pipe, 16, 20: Fuel pipe, 1
7, 21: control valve, 18, 22: shut-off valve, 23: ignition plug, 24: flame detector, 25: fuel, 26, 27: pigtail tube, 28: casing, 29: partition, 30: compressor, 31 ... air, 32, 33 ... fuel injection nozzle, 34
... premixing chamber, 35 ... flame stabilizer, 36, 37 ... liner, 38
... transition piece, 39 ... diffusion combustion flame, 40 ... premix combustion flame,
41: combustion gas, 42: turbine, 43: propagation tube.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Okabe 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant (72) Inventor Nariki Kobayashi 7-chome, Omika-cho, Hitachi City, Ibaraki Prefecture No. 2 1 Hitachi, Ltd. Power and Electricity Development Division (72) Inventor Kazuyuki Ito 7-2, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Electric Power and Electricity Development Division

Claims (5)

[Claims] 1. A gas turbine having a plurality of gas turbine combustors, wherein an ignition device is provided in the gas turbine combustor having the slowest fuel arrival time among the plurality of gas turbine combustors. gas turbine. 2. A gas turbine having a plurality of gas turbine combustors, wherein, among the plurality of gas turbine combustors, an ignition device is provided in a gas turbine combustor whose fuel injection start time is the latest. Gas turbine. 3. A gas turbine having a plurality of gas turbine combustors, a fuel pipe for supplying fuel, and a manifold pipe connected to the fuel pipe and supplying the fuel to each gas turbine combustor. The gas turbine according to claim 1, wherein an ignition device is provided in a gas turbine combustor farthest from the connection between the fuel mother pipe and the manifold pipe on the manifold pipe. 4. A plurality of gas turbine combustors provided substantially concentrically, a fuel mother pipe for supplying fuel, and a substantially annular ring connected to the fuel mother pipe and provided in each gas turbine combustor. A gas turbine having a manifold pipe for supplying the fuel, wherein an ignition device is provided in a gas turbine combustor positioned substantially opposite to a connection between the fuel mother pipe and the manifold pipe. . 5. A method for igniting a gas turbine that ignites a plurality of gas turbine combustors, wherein, among the plurality of gas turbine combustors, a gas turbine combustor with the slowest fuel arrival time is ignited. Gas turbine ignition method.