JP4386195B2 - Low NOx combustor for two-fluid cycle and operation method thereof - Google Patents

Description

  The present invention relates to a low-NOx combustor for a two-fluid cycle that can be applied to a thermoelectric variable cogeneration system and an operation method thereof.

  In recent years, cogeneration systems that improve power generation efficiency by combining gas turbines and steam turbines have attracted attention. FIG. 5 is a configuration diagram of a two-fluid cycle disclosed in Patent Document 1, in which water vapor 52 generated by exhaust heat E of the gas turbine equipment 51 is mixed with compressed air 54 by a mixer 53, and this mixed gas is discharged. By heating with heat E and injecting it into the combustor 55 of the gas turbine, the power generation output can be increased according to the power demand while supplying the surplus steam 52a as a utility. In this figure, 56 is an exhaust heat recovery boiler, A is air, F is fuel, and W is water supply.

On the other hand, in order to protect the environment, it is necessary to reduce NOx (nitrogen oxide) in the combustion exhaust gas of the gas turbine.
The main cause of NOx is so-called thermal NOx, in which nitrogen in the air is oxidized by a high-temperature flame at the time of combustion. To reduce this thermal NOx, hot spots in the flame are reduced to generate a high-temperature flame. It is effective to eliminate For this reason, in the above-described two-fluid cycle, a means for lowering the flame temperature by using water vapor is used, and a diffusion combustor capable of stable combustion even when water vapor is injected is used as the combustor.

  Further, for example, Patent Documents 2 and 3 disclose low NOx combustors in which steam injection is combined with a lean premixed combustor capable of reducing NOx without steam injection.

  The “premixed combustor and the cogeneration system having the combustor” of Patent Document 2 expand the operable range of the lean premixed combustor to the high combustion efficiency side, and low NOx by lean premixed combustion alone at low load In order to maintain NOx below the target value while maintaining the combustion efficiency at a high level at high loads, the premixed gas ejected from the premixed gas ejection hole 61 is steam as shown in FIG. The first steam supply means 62 that enables combustion in a state where the gas is added and the second steam supply means 64 that supplies steam to the vicinity of the combustion field outlet of the premixed gas in the combustion chamber cylinder 63 are provided. It is a thing.

  Patent Document 3 “Low NOx Combustor for Two-Fluid Cycle and Operation Method” can increase the output of a gas turbine by injecting a large amount of steam into the combustor when the power demand is large, and the power demand When the demand for steam is small and the demand for steam is large, the steam injection is completely eliminated while suppressing the generation of NOx, thereby aiming to increase utility steam and reduce fuel consumption, as shown in FIG. And a diffusion combustion type pilot burner 72 disposed in the center, and a plurality of premixed combustion type main burners 74 disposed therearound, and further air flowing into the fuel injection valve of the main burner, A steam injection pipe 76 that supplies water vapor so as to be mixed is provided.

Japanese Patent Publication No. 8-26780, JP 2000-329346 A, JP 2002-130664 A,

As described above, combining a Dry low-NOx combustor with a lean premixed combustor with a thermoelectric variable cogeneration system widens the range from Dry conditions that use generated steam as 100% heat to steam prioritization of power. Low NOx operation in a range becomes possible.
Further, in a Dry low NOx combustor combined with such variable thermoelectricity, in order to cope with an increase in NOx due to an increase in fuel accompanying an increase in the output of steam injection, by injecting part or all of the steam to be injected into the combustion region, NOx Increase, and low NOx operation over the entire load range was realized.

However, since the lean premix combustor is inferior in terms of combustion stability as compared with the diffusion combustor, there is a problem that the combustion efficiency is lowered when the steam injection amount is increased, and the amount of steam that can be injected is limited.
As a solution to this problem, it is conceivable to use a variable mechanism to reduce the air distribution to the combustion region and increase the fuel / air ratio in the combustion region. Adoption was difficult.

  The present invention has been developed to solve such problems. That is, an object of the present invention is to provide steam generated preferentially from a Dry condition in which steam generated in the exhaust heat recovery facility is supplied to the outside as a utility and steam is not injected into the combustor in a thermoelectric variable cogeneration system. A wide range of operation is possible up to the Wet condition that significantly increases power generation output by steam injection into the combustor, while preventing NOx and unburned components from increasing, maintaining low NOx operation and high combustion efficiency over the full load range An object of the present invention is to provide a low-NOx combustor for a two-fluid cycle and a method of operating the same.

According to the present invention, a lean premix combustor for lean premix combustion, a combustor liner that surrounds a flame generated in the lean premix combustor and guides combustion gas to the outside, a lean premix combustor, and a combustion A combustor casing that surrounds the combustor liner and supplies combustion air to the lean premix combustor through a gap with the combustor liner, and steam is supplied to the gap between the combustor liner and the combustor casing and mixed with the combustion air steam. A first steam supply line for forming the contained air, a second steam supply line for supplying steam to the downstream side of the flame of the combustor liner and mixing with the combustion gas to form a steam-containing combustion gas, and according to electric power demand A distribution control device that distributes and controls the amount of water vapor in the first water vapor supply line and the second water vapor supply line;
A gas sensor for detecting NOx concentration and unburned component concentration contained in the steam-containing combustion gas;
The distribution control device controls the amount of water vapor in the first water vapor supply line so that the detected NOx concentration does not exceed a predetermined threshold, and the second so that the detected unburned component concentration does not exceed the predetermined threshold. A low-NOx combustor for a two-fluid cycle is provided that controls the amount of water vapor in a water vapor supply line .

Further, according to the present invention, a lean premix combustor for lean premix combustion of fuel, a combustor liner that surrounds a flame generated in the lean premix combustor and guides combustion gas to the outside, and a lean premix combustor A combustor casing that surrounds the combustor liner and supplies combustion air to the lean premixed combustor through the gap between the combustor liner, and steam is supplied to the gap between the combustor liner and combustor casing to mix with the combustion air. A first steam supply line for forming steam-containing air, a second steam supply line for forming steam-containing combustion gas by supplying steam to the downstream side of the flame of the combustor liner and mixing with the combustion gas; And a distribution control device for distributing and controlling the amount of water vapor in the first water vapor supply line and the second water vapor supply line,
A gas sensor for detecting NOx concentration and unburned component concentration contained in the steam-containing combustion gas;
The distribution control device maintains the ratio of the amount of water vapor in the first water vapor supply line and the second water vapor supply line constant, and the first NOx concentration and the unburned component concentration do not exceed a predetermined threshold value. There is provided a low NOx combustor for a two-fluid cycle, characterized in that the total amount of water vapor in the water vapor supply line and the second water vapor supply line is controlled .

Further, according to the present invention, a lean premix combustor for lean premix combustion of fuel, a combustor liner that surrounds a flame generated in the lean premix combustor and guides combustion gas to the outside, and a lean premix combustor A combustor casing that surrounds the combustor liner and supplies combustion air to the lean premixed combustor through the gap between the combustor liner, and steam is supplied to the gap between the combustor liner and combustor casing to mix with the combustion air. A first steam supply line for forming steam-containing air, a second steam supply line for supplying steam to the downstream side of the flame of the combustor liner and mixing with the combustion gas to form the steam-containing combustion gas, and the steam-containing air A gas sensor for detecting the concentration of NOx contained in the combustion gas and the concentration of unburned components;
According to the electric power demand, the amount of water vapor in the first water vapor supply line and the second water vapor supply line is distributed and controlled ,
The amount of water vapor in the first water vapor supply line is controlled so that the detected NOx concentration does not exceed the predetermined threshold, and the amount of water vapor in the second water vapor supply line is controlled so that the detected unburned component concentration does not exceed the predetermined threshold. A method of operating a low-NOx combustor for a two-fluid cycle is provided.

According to the present invention, a lean premix combustor for lean premix combustion, a combustor liner that surrounds a flame generated in the lean premix combustor and guides combustion gas to the outside, a lean premix combustor, and a combustion A combustor casing that surrounds the combustor liner and supplies combustion air to the lean premix combustor through a gap with the combustor liner, and steam is supplied to the gap between the combustor liner and the combustor casing and mixed with the combustion air steam. A first steam supply line for forming the contained air; a second steam supply line for supplying steam to the downstream side of the flame of the combustor liner and mixing with the combustion gas to form a steam-containing combustion gas; and the steam-containing combustion gas A gas sensor for detecting the NOx concentration and unburned component concentration contained in
According to the electric power demand, the amount of water vapor in the first water vapor supply line and the second water vapor supply line is distributed and controlled,
The first steam supply line and the second steam supply line are maintained at a constant ratio between the first steam supply line and the second steam supply line, and the detected NOx concentration and unburned component concentration do not exceed a predetermined threshold. A method for operating a low-NOx combustor for a two-fluid cycle is provided, which controls the total amount of water vapor in the water vapor supply line .

  According to the apparatus and method of the present invention described above, since the lean premixed combustor for lean premixed combustion of fuel is provided, in the thermoelectric variable cogeneration system, water vapor generated in the exhaust heat recovery facility is externally used as a utility. In the Dry condition in which steam is not injected into the combustor, generation of NOx and unburned components can be suppressed, and low NOx operation and high combustion efficiency can be obtained.

  Further, since the amount of water vapor in the first water vapor supply line and the second water vapor supply line is distributed and controlled according to the electric power demand, the wet condition preferentially injects the generated steam into the combustor to greatly increase the power generation output. In the above, the steam is supplied from the first steam supply line to the gap between the combustor liner and the combustor casing and mixed with the combustion air to form the steam-containing air. The amount of combustion can be increased and the power generation output can be increased while suppressing the generation of NOx.

Furthermore, in this Wet condition, since the steam is supplied from the second steam supply line to the downstream side of the flame of the combustor liner and mixed with the combustion gas to form the steam-containing combustion gas, the working fluid that flows downstream from the combustion region (Combustion gas + liner inflow air + steam) increases, the back pressure in the liner rises due to an increase in working fluid, restricts the amount of air flowing in from the upstream of the liner, and under conditions where the amount of steam injection is large, combustion air Can be limited.
The restricted air becomes scroll cooling air that is relatively easy to flow in, and is introduced into the mainstream gas from a region not directly related to combustion.

Therefore, it is possible to operate in a wide range, prevent an increase in NOx and unburned components, and maintain a low NOx operation and a high combustion efficiency in the full load range. That is, according to the present invention, air to the combustion region can be maintained. Steam that has the same effect as a variable mechanism that can maintain the stable combustion condition by changing the amount according to the operating conditions, but with a relatively simple mechanism. Even with the injection amount, stable combustion can be secured.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is an overall configuration diagram of a low-NOx combustor for a two-fluid cycle according to the present invention. As shown in this figure, the low-NOx combustor for a two-fluid cycle of the present invention includes a lean premix combustor 12, a combustor liner 14, a combustor casing 16, a first steam supply line 22, and a second steam supply line 24. A gas sensor 26 and a distribution control device 30.

The lean premixed combustor 12 is a combustor that premixes and homogenizes a large amount of air 5 (water vapor-containing air described later) introduced from the fuel 1 and performs lean premixed combustion. In this example, a plurality of lean premix combustors 12 are arranged at the upper end of the combustor liner 14.
Further, in this example, a diffusion combustor 11 is disposed in the center of a plurality of lean premix combustors 12 so that the fuel 1 is diffusely burned using air 5 (water vapor-containing air described later) introduced from the periphery thereof. It has become.
Moreover, it is preferable to provide an ignition plug (igniter) (not shown) so as to ignite the fuel in the diffusion combustor 11.
In the present invention, the diffusion combustor 11 is not essential, and may be omitted as long as stable combustion is possible, or after reaching stable combustion after ignition, the amount of combustion by the diffusion combustor 11 is reduced, Alternatively, combustion may be stopped. The fuel 1 is preferably a gas fuel, but the present invention is not limited to this and may be a liquid fuel.
Further, in this example, fuel control valves 11a and 12a for adjusting the flow rate of the fuel 1 are provided.

The combustor liner 14 surrounds the flames 7a and 7b generated in the diffusion combustor 11 and the lean premixed combustor 12, and has a function of guiding the combustion gas 6 (steam-containing combustion gas described later) to the outside (for example, a gas turbine). .
On the downstream side of the flame of the combustor liner 14, a plurality of through holes that directly pass through the second water vapor supply line 24 are preferably provided. Further, the further downstream side of the combustor liner 14 is a scroll portion 14a, which is formed in a spiral shape to guide the steam-containing combustion gas 6 to the gas turbine.
The scroll portion 14a is provided with a large number of fine through holes for directly introducing the outside air 2 into the inside and cooling the scroll portion. The through holes for cooling are preferably provided in portions other than the scroll portion of the combustor liner as necessary.

The combustor casing 16 surrounds the diffusion combustor 11 and the lean premixed combustor 12 and the combustor liner 14, and the diffusion combustor 11 and the lean premixed combustor through the gap between the combustor casing 16 and the combustor liner 14. 12 has a function of supplying the combustion air 2 to the fuel cell 12.
This combustion air 2 is supplied from an air compressor (not shown).
Further, the combustor casing 16 is provided with a through hole that directly passes the second steam supply line 24 downstream from the flame, and further, an intermediate position between the second steam supply line 24 of the combustor casing 16 and the lean premixed combustor 12. Is preferably provided with a plurality of through-holes directly passing through the first water vapor supply line 22.

The first water vapor supply line 22 supplies the water vapor 3 to the gap between the combustor liner 14 and the combustor casing 16 through the through hole provided in the combustor casing 16 and mixes it with the combustion air 2 so that the water vapor containing air 5 is mixed. Form.
The first steam supply line 22 has a first steam control valve 23 in the middle thereof, and can freely adjust the flow rate of steam supplied from the steam supply source.

The second water vapor supply line 24 supplies the water vapor 4 to the downstream side of the flames 7a, 7b of the combustor liner 14 through the through holes provided in the combustor casing 16 and the combustor liner 14, and mixes it with the combustion gas. The contained combustion gas 6 is formed.
The second steam supply line 24 has a second steam control valve 25 in the middle thereof, and can freely adjust the flow rate of steam supplied from the steam supply source.

  The steam supply source of the steam supply lines 22 and 24 is preferably an exhaust heat recovery boiler that generates steam by exhaust heat of the gas turbine. The steam supply source is not limited to this, and other surplus steam may be used.

  The gas sensor 26 is attached to the downstream side of the scroll portion 14a, and detects the NOx concentration and the unburned component concentration contained in the steam-containing combustion gas. The gas sensor 26 is preferably a gas detector capable of detecting NOx concentration and unburned component concentration (CO or hydrocarbon) in real time. Further, the gas sensor 26 may be in the gas turbine downstream of the scroll portion 14a or in the exhaust heat recovery boiler downstream thereof.

  The distribution control device 30 is, for example, a computer, and controls the fuel control valves 11a and 12a and the steam control valves 23 and 25 described above. The distribution control device 30 controls the fuel control valves 11 a and 12 a according to the power demand command 8 and also controls the steam control valves 23 and 25 to control the first steam supply line 22 and the second steam supply line 24. Distribution control of the amount of water vapor.

  Combustion air 2 supplied from an air compressor (not shown) having the above-described configuration flows through the gap between the combustor casing 16 and the combustor liner 14 and reaches the diffusion combustor 11 and the lean premixed combustor 12. It flows into the liner 14 through the combustor 11 and the lean premixed combustor 12 to form flames 7a and 7b, and the generated combustion gas is guided to a gas turbine (not shown) through the scroll portion 14a to drive it. To do.

FIG. 2 is an exhaust gas characteristic diagram according to the operation method of the first embodiment of the present invention, and FIG. 3 is an exhaust gas characteristic diagram according to the conventional operation method.
In these figures, the horizontal axis represents the fuel flow rate, and the vertical axis represents the engine output, the amount of steam, the NOx concentration, and the unburned component concentration.

  Under the Dry condition (dry region) in which water vapor is not injected into the combustor, the engine output, that is, the power generation output increases substantially in proportion to the increase in the fuel flow rate in FIGS. Further, when the fuel flow rate increases, the combustion becomes more stable, so the concentration of unburned components decreases and the combustion efficiency improves. Further, in the present invention, since the lean premix combustor 12 for lean premix combustion of the fuel is provided, the generation of NOx and unburned components can be suppressed in the dry region, and low NOx operation and high combustion efficiency can be obtained. it can.

In FIG. 2, in the method of the present invention, the distribution controller 30 sets the water vapor amount A of the first water vapor supply line 22 so that the unburned component concentration detected by the gas sensor 26 does not exceed a predetermined threshold (for example, 150 ppm). Control.
As shown in FIG. 3, when the amount of water vapor in the first water vapor supply line 22 is increased and the amount of water vapor becomes excessive, combustion in the lean premixed combustor 12 becomes unstable and the concentration of unburned components increases rapidly. Show the trend.

In order to suppress this unburned component concentration, in the method of the present invention, the unburned component concentration is monitored by the gas sensor 26, and in this example, the first water vapor supply is approximately proportional to the increase in the fuel flow rate and the engine output. Only the water vapor amount A in the line 22 is increased, the unburned component concentration gradually increases from the dry region, and the water vapor amount in the first water vapor supply line 22 is kept constant before reaching a predetermined threshold value.
By this method, the combustion in the lean premix combustor 12 can be stably maintained, and the increase tendency of the unburned component concentration can be suppressed.

When the electric power demand further increases, the NOx concentration detected by the gas sensor 26 and the unburned component concentration are set to respective predetermined threshold values (for example, 20 ppm) while keeping the water vapor amount A of the first water vapor supply line 22 constant. And the water vapor amount B of the second water vapor supply line 24 is controlled so as not to exceed 150 ppm.
When steam is supplied from the second steam supply line 24 to the downstream side of the flames 7a and 7b of the combustor liner and mixed with the combustion gas to form the steam-containing combustion gas 6, the operation flows into the downstream of the combustion region. Fluid (combustion gas + liner inflow air + steam) increases, the back pressure in the liner rises due to an increase in working fluid, restricts the amount of air flowing in from the upstream of the liner, and is used for combustion under conditions where there is a large amount of steam injection Limiting the air can also suppress the generation of unburned components.
Further, the restricted air becomes scroll cooling air that is relatively easy to flow in, and is introduced into the mainstream gas from a region not directly related to combustion.

Accordingly, as shown in FIG. 2, the total amount of water vapor is increased and the engine output, that is, the power generation output is increased while maintaining both the NOx concentration and the unburned component concentration below the predetermined threshold values (for example, 20 ppm and 150 ppm). Can do.
If the unburned component concentration exceeds a predetermined threshold due to the increase in the water vapor amount B in the second water vapor supply line 24, the water vapor amount A in the first water vapor supply line 22 may be decreased.
Conversely, when NOx has increased due to the restriction of combustion air, the amount of water vapor in the first water vapor line 22 may be increased within the threshold for unburned components.

  FIG. 4 is an exhaust gas characteristic diagram according to the operation method of the second embodiment of the present invention. In this example, the distribution control device 30 maintains the ratio of the amount of water vapor (for example, 3: 2) in the first water vapor supply line 22 and the second water vapor supply line 24 to be constant, and the detected NOx concentration and unburned components. The total water vapor amount (A + B) of the first water vapor supply line 22 and the second water vapor supply line 24 is controlled so that the concentration does not exceed the respective predetermined threshold values (for example, 20 ppm and 150 ppm).

  According to the apparatus and method of the present invention described above, since the lean premix combustor 12 for lean premix combustion of the fuel 1 is provided, the steam generated in the exhaust heat recovery facility is utility in the thermoelectric variable cogeneration system. As described above, in a Dry condition in which steam is not supplied to the combustor by being supplied to the outside, generation of NOx and unburned components can be suppressed, and low NOx operation and high combustion efficiency can be obtained.

  In addition, since the water vapor amounts A and B of the first water vapor supply line 22 and the second water vapor supply line 24 are distributed and controlled according to the electric power demand, the generated steam is preferentially injected into the combustor to greatly generate power output. In the wet condition for increasing the steam, the steam is supplied to the gap between the combustor liner and the combustor casing from the first steam supply line 22 and is mixed with the combustion air to form the steam-containing air 5. It can be uniformly mixed and introduced into the combustor, and the power generation output can be increased by increasing the combustion amount while suppressing the generation of NOx.

Further, under this Wet condition, water vapor is supplied from the second water vapor supply line 24 to the downstream side of the flame of the combustor liner and mixed with the combustion gas to form the water vapor-containing combustion gas 6, so that it flows downstream from the combustion region. The working fluid (combustion gas + liner inflow air + steam) increases, the back pressure in the liner rises due to the increase in working fluid, restricts the amount of air flowing in from the upstream of the liner, and burns under conditions where there is a large amount of steam injection The production of unburned components can be suppressed by limiting the working air.
The restricted air becomes scroll cooling air that is relatively easy to flow in, and is introduced into the mainstream gas from a region not directly related to combustion.

Therefore, it is possible to operate in a wide range, prevent an increase in NOx and unburned components, and maintain a low NOx operation and a high combustion efficiency in the full load range. That is, according to the present invention, air to the combustion region can be maintained. Steam that has the same effect as a variable mechanism that can maintain the stable combustion condition by changing the amount according to the operating conditions, but with a relatively simple mechanism. Even with the injection amount, stable combustion can be secured.

  The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the scope of the invention.

1 is an overall configuration diagram of a low-NOx combustor for a two-fluid cycle according to the present invention. It is an exhaust gas characteristic figure by the operation method of a 1st embodiment of the present invention. It is an exhaust gas characteristic figure by the conventional operation method. It is an exhaust gas characteristic figure by the operation method of a 2nd embodiment of the present invention. It is a block diagram which shows an example of the conventional 2 fluid cycle. It is a block diagram of the combustor of patent document 2. FIG. It is a block diagram of the combustor of patent document 3.

Explanation of symbols

1 fuel, 2 combustion air, 3 water vapor, 4 water vapor,
5 steam-containing air, 6 steam-containing combustion gas,
7a, 7b flame, 8 power demand command,
11 diffusion combustor, 12 lean premix combustor,
11a, 12a Fuel control valve, 14 Combustor liner,
14a scroll part, 16 combustor casing,
22 first steam supply line, 23 first steam control valve,
24 second steam supply line, 25 second steam control valve,
26 gas sensor, 30 distribution control device

Claims (4)

A lean premixed combustor for lean premixed combustion of fuel, a combustor liner that surrounds a flame generated by the lean premixed combustor and guides combustion gas to the outside, and a combustor that surrounds the lean premixed combustor and the combustor liner A combustor casing for supplying combustion air to the lean premixed combustor through the gap with the liner, and steam is supplied to the gap between the combustor liner and the combustor casing and mixed with the combustion air to form steam-containing air. 1 steam supply line, a second steam supply line for supplying steam to the downstream side of the flame of the combustor liner and mixing with the combustion gas to form a steam-containing combustion gas, and a first steam supply line according to the power demand A distribution controller for distributing and controlling the amount of water vapor in the second water vapor supply line;
A gas sensor for detecting NOx concentration and unburned component concentration contained in the steam-containing combustion gas;
The distribution control device controls the amount of water vapor in the first water vapor supply line so that the detected NOx concentration does not exceed a predetermined threshold, and the second so that the detected unburned component concentration does not exceed the predetermined threshold. A low NOx combustor for a two-fluid cycle, characterized by controlling the amount of water vapor in a water vapor supply line . A lean premixed combustor for lean premixed combustion of fuel, a combustor liner that surrounds a flame generated by the lean premixed combustor and guides combustion gas to the outside, and a combustor that surrounds the lean premixed combustor and the combustor liner A combustor casing for supplying combustion air to the lean premixed combustor through the gap with the liner, and steam is supplied to the gap between the combustor liner and the combustor casing and mixed with the combustion air to form steam-containing air. 1 steam supply line, a second steam supply line for supplying steam to the downstream side of the flame of the combustor liner and mixing with the combustion gas to form a steam-containing combustion gas, and a first steam supply line according to the power demand A distribution controller for distributing and controlling the amount of water vapor in the second water vapor supply line;
A gas sensor for detecting NOx concentration and unburned component concentration contained in the steam-containing combustion gas;
The distribution control device maintains the ratio of the amount of water vapor in the first water vapor supply line and the second water vapor supply line constant, and the first NOx concentration and the unburned component concentration do not exceed a predetermined threshold value. A low NOx combustor for a two-fluid cycle, wherein the total amount of water vapor in the water vapor supply line and the second water vapor supply line is controlled . A lean premixed combustor for lean premixed combustion of fuel, a combustor liner that surrounds a flame generated by the lean premixed combustor and guides combustion gas to the outside, and a combustor that surrounds the lean premixed combustor and the combustor liner A combustor casing for supplying combustion air to the lean premixed combustor through the gap with the liner, and steam is supplied to the gap between the combustor liner and the combustor casing and mixed with the combustion air to form steam-containing air. 1 steam supply line, a second steam supply line for supplying steam to the downstream side of the flame of the combustor liner and mixing with the combustion gas to form a steam-containing combustion gas, and a NOx concentration contained in the steam-containing combustion gas, A gas sensor that detects the unburned component concentration,
According to the electric power demand, the amount of water vapor in the first water vapor supply line and the second water vapor supply line is distributed and controlled ,
The amount of water vapor in the first water vapor supply line is controlled so that the detected NOx concentration does not exceed the predetermined threshold, and the amount of water vapor in the second water vapor supply line is controlled so that the detected unburned component concentration does not exceed the predetermined threshold. A method for operating a low-NOx combustor for a two-fluid cycle. A lean premixed combustor for lean premixed combustion of fuel, a combustor liner that surrounds a flame generated by the lean premixed combustor and guides combustion gas to the outside, and a combustor that surrounds the lean premixed combustor and the combustor liner A combustor casing for supplying combustion air to the lean premixed combustor through the gap with the liner, and steam is supplied to the gap between the combustor liner and the combustor casing and mixed with the combustion air to form steam-containing air. 1 steam supply line, a second steam supply line for supplying steam to the downstream side of the flame of the combustor liner and mixing with the combustion gas to form a steam-containing combustion gas, and a NOx concentration contained in the steam-containing combustion gas, A gas sensor that detects the unburned component concentration,
According to the electric power demand, the amount of water vapor in the first water vapor supply line and the second water vapor supply line is distributed and controlled ,
The first steam supply line and the second steam supply line are maintained at a constant ratio between the first steam supply line and the second steam supply line, and the detected NOx concentration and unburned component concentration do not exceed a predetermined threshold. A method for operating a low-NOx combustor for a two-fluid cycle, wherein the total amount of water vapor in the water vapor supply line is controlled .