JP7457851B2 - Gas turbine combustor - Google Patents

Description

The present invention relates to a combustor for a gas turbine.

Technology is known for improving ignition or combustion stability by using a fuel different from the main fuel when starting up a gas turbine. In the following Patent Document 1, low-volatility heavy oil A or light oil is used as the main fuel, and gas fuel is used for ignition to improve ignition at low temperatures. In the following Patent Document 2, when a hydrogen-containing gas fuel with a wide flammable range is used as the main fuel, liquid fuel or liquefied natural gas is used as the startup fuel during ignition and startup to prevent the emission of unburned hydrogen.

Japanese Patent Application Publication No. 9-105335 Japanese Patent Application Publication No. 2010-133339

In recent years, consideration has been given to using ammonia, which is a hydrogen carrier, as a fuel. When ammonia is used as fuel for a gas turbine, ammonia has poor ignitability, and combustion stability during startup may decrease.

The present invention aims to improve the stability during start-up of a gas turbine using ammonia as fuel.

A gas turbine combustor according to the present invention includes a combustion chamber, a main fuel nozzle that supplies ammonia as fuel to the combustion chamber, an air nozzle that supplies compressed air to the combustion chamber, and an ignition ignition valve disposed in the combustion chamber. The spark plug includes a plug, a reformer for reforming ammonia into reformed fuel containing hydrogen, and a reformed fuel nozzle for supplying the reformed fuel to the vicinity of the spark plug.

Ignition performance is improved by reforming ammonia to obtain hydrogen and sending the reformed fuel containing hydrogen to the vicinity of the spark plug.

The reformer may include a heater that heats ammonia and a catalyst that decomposes ammonia into hydrogen and nitrogen.

The reformed fuel nozzle can be an injection valve that can be opened and closed.

The combustor of the gas turbine may include a main fuel nozzle or a sub-fuel pipe that branches off from a main fuel pipe that delivers ammonia to the main fuel nozzle and sends ammonia to a reformer.

The auxiliary fuel pipe may be provided with a shutoff valve that stops the supply of ammonia to the reformer.

The combustion chamber may include a main combustion chamber and a sub-combustion chamber that are separated from each other and communicated through a communication hole, and the main combustion chamber is supplied with ammonia by a main fuel nozzle, and the sub-combustion chamber is supplied with ammonia. A spark plug is disposed and reformed fuel is supplied by a reformed fuel nozzle.

The heater may be configured to perform heating when reformed fuel is not being supplied by the reformed fuel nozzle, and the reformed fuel nozzle may be configured to supply reformed fuel after heating by the heater is stopped. It is possible to do so.

The reformed fuel nozzle may provide reformed fuel until the gas turbine reaches self-sustaining speed.

Another gas turbine combustor according to the present invention includes a combustion chamber, a spark plug disposed in the combustion chamber, a reformer for reforming ammonia into reformed fuel containing hydrogen, and a reformer for reforming ammonia into reformed fuel containing hydrogen. It includes a reformed fuel nozzle that supplies near the spark plug, and a control unit that controls the timing of supply of the reformed fuel and the timing of ignition by the spark plug. Furthermore, the control unit can stop the supply of reformed fuel based on the rotational speed of the gas turbine.

By supplying reformed fuel containing hydrogen near the spark plug, ignition performance is improved and gas turbine operation becomes stable during startup. Furthermore, since the main fuel, ammonia, is reformed to obtain the ignition fuel, there is no need to separately prepare ignition fuel.

FIG. 1 is a schematic diagram showing an overall configuration of a gas turbine. FIG. 2 is a schematic diagram showing an example of the configuration of a combustor, and is a diagram showing an example including an injection valve that injects reformed fuel into a combustion chamber. It is a schematic diagram which shows another example of a structure of a combustor, and is a figure which shows an example which supplies reformed fuel to a combustion chamber through piping. It is a schematic diagram which shows yet another example of a structure of a combustor, and is a figure which shows the example which provided the auxiliary combustion chamber inside the combustion chamber liner. It is a schematic diagram which shows yet another example of a structure of a combustor, and is a figure which shows the example which provided the auxiliary combustion chamber outside the combustion chamber liner.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a schematic configuration of a gas turbine 10. As shown in FIG. The gas turbine 10 includes a compressor 12 that compresses air, a combustor 14 that mixes and burns the air compressed by the compressor 12 and fuel to generate combustion gas, and a turbine 16 that is driven by the combustion gas. The rotors of the compressor 12 and the turbine 16 are connected by an output shaft 18 and rotate as one. A starter motor 20 is connected to the output shaft 18 and rotates the rotor of the compressor 12 and the turbine 16 when the gas turbine 10 is started. Ammonia, which is fuel, is supplied to the combustor 14 from a fuel tank 22 via a main fuel pipe 23. The main fuel pipe 23 is equipped with a fuel pump, and ammonia is fed under pressure by a pump or a gas compressor. The gas turbine 10 is equipped with a control device 24, and the control device 24 controls the supply of fuel and controls the operation of the starter motor 20 during startup based on the required output, the rotational speed of the output shaft 18 detected by the rotational speed sensor 25, and the like. Control etc.

FIG. 2 is a diagram schematically showing an example of the configuration of the combustor 14. The combustor 14 includes a combustion chamber liner 28 that defines a combustion chamber 26 and a flow sleeve 30 that surrounds the combustion chamber liner 28. Air compressed by the compressor 12 (hereinafter referred to as compressed air) flows between the combustion chamber liner 28 and the flow sleeve 30, and is fed into the combustion chamber 26 from the air nozzle 32. A swirler 34 may be disposed at the outlet of the air nozzle 32 to swirl the supplied compressed air to form a swirling flow within the combustion chamber 26 .

Combustor 14 has a main fuel nozzle 36 that supplies ammonia into combustion chamber 26 . The aforementioned air nozzle 32 is arranged to surround the main fuel nozzle 36. Ammonia supplied from the main fuel nozzle 36 and compressed air supplied from the air nozzle 32 mix in the combustion chamber 26 to form an air-fuel mixture. The combustor 14 includes a reformer 38 that decomposes ammonia, which is a fuel, to generate fuel containing hydrogen (hereinafter referred to as reformed fuel). A portion of the ammonia sent to or sent to the main fuel nozzle 36 is supplied to the reformer 38 via an auxiliary fuel pipe 40 . The auxiliary fuel pipe 40 may branch from the main fuel pipe 23 or may branch from the main fuel nozzle 36.

The reformer 38 includes a carrier supporting a catalyst for decomposing ammonia into hydrogen and nitrogen, and a catalyst housing that houses the carrier. Ruthenium or nickel can be used as the catalyst. The reformer 38 has a heater 42 that heats the supplied ammonia, and the heating accelerates the decomposition reaction of ammonia. The heater 42 may be a heater that generates heat using electric power, and may be attached to the catalyst housing. Alternatively, electric power may be supplied to the catalyst carrier so that the carrier itself generates heat. The heater 42 generates heat when necessary by power supply controlled by the control device 24. The reformed fuel generated by the reformer 38 is sent to an injection valve 44 fixed to the combustion chamber liner 28 and injected from the injection valve 44 into the combustion chamber 26. A spark plug 46 is also fixed to the combustion chamber liner 28, and the injection valve 44 injects reformed fuel near the spark plug 46. The injection valve 44 opens and closes based on commands from the control device 24 to inject the required amount of reformed fuel at the required timing. Since reformed fuel contains hydrogen, it has good ignitability and can be easily ignited. This becomes a spark and ignites the air-fuel mixture in the combustion chamber 26. The timing of injection of reformed fuel by the injection valve 44 and the timing of ignition by the spark plug 46 are controlled by the control device 24.

The auxiliary fuel pipe 40 may be provided with a valve capable of shutting off the auxiliary fuel pipe 40, for example, a check valve. By providing such a valve, hydrogen generated in the reformer 38 can be prevented from flowing backward.

Heating by the heater 42 may be performed before the reformed fuel is injected by the injector 44, and the reformed fuel may be injected by the injector 44 after heating is stopped. Ammonia can be reformed by residual heat for a certain period of time even after heating is stopped. After the temperature of the heater 42 is lowered by being cooled by the supplied ammonia, hydrogen is no longer generated, and hydrogen generation after the supply of the reformed fuel is suppressed. At this time, the heating by the heater 42 and the injection valve 44 are controlled by the control device 24.

The supply of reformed fuel may be continued until the gas turbine 10 reaches a speed that allows self-sustaining operation, that is, until the starter motor 20 no longer needs to be driven. At a speed below which self-sustaining operation is possible, combustion is unstable, and at this time, combustion can be stabilized by supplying reformed fuel with good ignitability. Based on the detected value of the rotational speed sensor 25, it can be determined whether the gas turbine 10 has reached a speed that allows self-sustaining operation.

FIG. 3 is a schematic diagram showing another example of the configuration of the combustor. Components that are the same as those of the combustor 14 described above are designated by the same reference numerals, and the description thereof will be omitted. The combustor 48 differs from the above-described combustor 14 in components related to reformed fuel. The reformer 38 and the heater 42 provided in the reformer 38 are the same as those described above. The combustor 48 is not provided with the injection valve 44, but is provided with a reformed fuel pipe 50 extending from the reformer 38 and opening into the combustion chamber 26. A shield valve 52 is provided in the auxiliary fuel pipe 40 . The shield valve 52 opens and closes based on commands from the control device 24. When the shield valve 52 is open, ammonia is sent from the main fuel pipe 23 to the reformer 38 via the auxiliary fuel pipe 40, is converted into reformed fuel in the reformer 38, and is combusted from the reformed fuel pipe 50. It is sent to the vicinity of the spark plug 46 within the chamber 26.

FIG. 4 is a schematic diagram showing still another configuration example of the combustor. Components that are the same as those of the combustor 14 described above are designated by the same reference numerals, and the description thereof will be omitted. The combustor 54 shown in FIG. 4 has a combustion chamber 56 that is different in structure from the combustion chamber 26 of the combustor 14 described above. The combustion chamber 56 includes a main combustion chamber 58 that occupies most of the space inside the combustion chamber liner 28 , and a sub-combustion chamber 60 that is separated from the main combustion chamber 58 and is part of the space inside the combustion chamber liner 28 . include. The main combustion chamber 58 and the sub-combustion chamber 60 communicate with each other through one or more communication holes 62 . Compressed air is sent from the air nozzle 32 to the main combustion chamber 58, and ammonia is sent from the main fuel nozzle 36 to form an air-fuel mixture. Reformed fuel is sent to the sub-combustion chamber 60 from the injection valve 44 . The reformed fuel sent to the sub-combustion chamber 60 is ignited by the spark plug 46, and the reformed fuel is combusted. This combustion gas is ejected into the main combustion chamber 58 through the communication hole 62, and the high-temperature combustion gas raises the temperature of the air-fuel mixture in the main combustion chamber 58, igniting ammonia. By injecting the reformed fuel into the sub-combustion chamber 60, diffusion of the reformed fuel is suppressed and ignition can be performed with a small amount.

FIG. 5 is a schematic diagram showing still another configuration example of the combustor. Components that are the same as those of the combustor 14 described above are designated by the same reference numerals, and the description thereof will be omitted. The combustor 64 shown in FIG. 5 has a combustion chamber 66 that is different in structure from the combustion chamber 26 of the combustor 14 described above. The combustion chamber 66 includes a main combustion chamber 68, which is a space inside the combustion chamber liner 28, and a sub-combustion chamber 70, which is provided adjacent to the outside of the combustion chamber liner 28. The main combustion chamber 68 and the auxiliary combustion chamber 70 are separated by the combustion chamber liner 28 and communicated through one or more communication holes 72 provided in the combustion chamber liner 28 . Compressed air is sent from the air nozzle 32 to the main combustion chamber 68, and ammonia is sent from the main fuel nozzle 36 to form an air-fuel mixture. Reformed fuel is sent to the sub-combustion chamber 70 from the injection valve 44 . The reformed fuel sent to the sub-combustion chamber 70 is ignited by the spark plug 46, and the reformed fuel is combusted. This combustion gas is ejected into the main combustion chamber 68 through the communication hole 72, and the high-temperature combustion gas raises the temperature of the air-fuel mixture in the main combustion chamber 68, igniting ammonia. By injecting the reformed fuel into the sub-combustion chamber 70, the diffusion of the reformed fuel is suppressed and ignition can be performed with a small amount.

The above-mentioned injection valve 44 and ignition plug 46 may be provided in multiple numbers. The reformer 38 may be provided for each injection valve 44, or one for each of the multiple injection valves 44. The above-mentioned reformed fuel pipe 50 and ignition plug 46 may be provided in multiple numbers. The reformer 38 may be provided for each reformed fuel pipe 50, or one for each of the multiple reformed fuel pipes 50. A plurality of auxiliary combustion chambers 60, 70 may be provided. Furthermore, the gas turbine 10 may be provided with a plurality of combustors 14, 48, 54, 64. Ammonia may be supplied by a pump, or high-pressure ammonia may be stored and supplied to the main fuel nozzle 36 and the reformer 38 from there.

10 gas turbine, 12 compressor, 14, 48, 54, 64, combustor, 16 turbine, 22 fuel tank, 23 main fuel piping, 26, 56, 66 combustion chamber, 28 combustion chamber liner, 30 flow sleeve, 32 air nozzle , 36 main fuel nozzle, 38 reformer, 40 auxiliary fuel piping, 42 heater, 44 injection valve, 46 spark plug, 50 reformed fuel piping, 52 shielding valve, 58, 68 main combustion chamber, 60, 70 auxiliary combustion Chamber, 62, 72 communication hole.

Claims (4)

A gas turbine combustor,
a combustion chamber;
a main fuel nozzle that supplies ammonia to the combustion chamber;
a spark plug disposed in the combustion chamber;
a reformer that reforms a part of the ammonia sent to or sent to the main fuel nozzle by heating to produce a reformed fuel containing hydrogen;
a reformed fuel nozzle that supplies the reformed fuel to the vicinity of the spark plug;
a control unit that controls timing of heating in the reformer, timing of supplying the reformed fuel, and timing of ignition by the spark plug;
A gas turbine combustor comprising: The combustor for a gas turbine according to claim 1, wherein the control section stops supplying the reformed fuel based on the rotational speed of the gas turbine. 2. The combustor of claim 1, further comprising:
an air nozzle that supplies compressed air around the ammonia supplied from the main fuel nozzle to the combustion chamber;
Equipped with
The spark plug is arranged on a side opposite to the side where the main fuel nozzle and the air nozzle are located with respect to the reformed fuel nozzle.
Gas turbine combustor. 2. The gas turbine combustor according to claim 1, wherein the reformer includes a heater that generates heat using electric power and heats ammonia, and the heating is controlled by controlling the electric power supplied to the heater. A gas turbine combustor with controlled timing.