JPH05196232A - Back fire-resistant fuel staging type premixed combustion apparatus - Google Patents

Abstract

PURPOSE: To obtain an engine in which emission of NOx, CO and UHC is reduced while suppressing damage due to backfire. CONSTITUTION: In order to reduce emission of nitrogen oxides, carbon monoxide and unburnt hydrocarbon, flame temperature must be kept between 1371 deg.C (2500 deg.F) and 1538 deg.C (2800 deg.F). Fuel and air are mixed using a premixing tube and mixture gas is combusted in a combustion chamber 7. Since air/fuel mixture gas passes through premixing tubes 8, 10, 12, 16, 18, 20, the premixing tubes have anti-backfire properties. When a load acting on a combustor is required to decrease significantly lower than 100% of maximum load during off-peak time, for example, low emission and low flame temperature can be sustained even if the load is reduced by regulating the flow rate of fuel and air.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention provides a compact flashback resistance.
The present invention relates to a premixing combustion device using a highly efficient premixing pipe. this
Combustors use nitrogen over most of the engine's operating range.
Oxide (NO _x) And carbon monoxide (CO) and unburned hydrocarbons
Reduce (UHC) emissions.

[0002]

BACKGROUND OF THE INVENTION In some conventional combustion systems, fuel and
Flame temperature by utilizing a design that includes air premixing
Reduce the degree to NO_xIt is known to reduce emissions.
The premixer in each such combustion device has a reverse
It is easily damaged by fire, and such flashback causes compressor stall.
Occasionally occurs during such transients. In addition, conventional design
Many of these combustion devices are
A small amount of NO over the minute _xAnd the ability to emit CO and UHC
Lack of strength. Such low emission performance is
Engine applications that require significantly reduced operation, such as gas
Used for pipeline and oil platform compressor drive applications
It is profitable.

[0003]

As is apparent from the above, in the art, the following air-fuel premixing combustion apparatus, that is, a fuel and air are efficiently mixed by simple parts and a unique structure, While having at least equal characteristics in the combustion characteristics of the premixing burner, greatly reduced and premixed as emissions of the NO _x and CO and UHC little over a substantial portion of the engine operating range the risk of damage due to flashback simultaneously A combustor is needed. It is an object of the present invention to meet this and other needs in the manner set forth in the description below.

[0004]

SUMMARY OF THE INVENTION Briefly stated, the present invention addresses these needs by the following combustors, namely, a combustion chamber that burns a mixture of fuel and air, and fuel and air prior to entering the combustion chamber. A plurality of premixing combustor tubes for premixing having first and second ends and a plurality of holes disposed at the first end and a second end disposed substantially within the combustion chamber. Premixed combustor tubes, fuel introduction means connected to the first ends of these premixed combustor tubes, air introduction means for introducing air into the premixed combustor tubes, and fuel introduction means And a control means for controlling the air introduction means.

In the preferred embodiment, the fuel and air enter the combustion chamber after being substantially completely mixed in the premix combustor tube. Further, the combustion means is controlled by the control means so that the maximum load action is 10
It can operate at loads well below 0%. Finally, the combustion device may use gaseous or liquid fuels. In another preferred embodiment, the potential for CO and UHC increases is minimized when the combustor operates at loads well below 100% of full load operation.

In a particularly preferred embodiment, the combustion device of the present invention comprises a combustion chamber, 42 premixing tubes whose ends are arranged in staggered positions within the combustion chamber, a premixing tube and a combustor. It consists of a fuel and air control system that controls the fuel and air being introduced, and therefore the combustion system is one of its maximum load functions.
It is possible to reduce the possibility of increased CO and UHC emissions even when operating at loads well below 00%.

The preferred combustion device according to the invention has the following advantages: easy assembly and repair, good stability, good economic efficiency, improved load action performance, high strength safety, flashback generation. Results in a reduced likelihood and good fuel efficiency. In fact, in many of the preferred embodiments, the factors of good economy, improved load action performance, and reduced likelihood of flashback are significantly higher than previously achieved with known conventional combustion devices. Optimized.

The above and other features of the invention will become more apparent from the following detailed description in conjunction with the accompanying drawings. The same reference numerals denote the same parts throughout the drawings.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to achieve extremely low NO _x emissions, the flame temperature must be kept below 2800 ° F., as is well known. Also, to reduce CO and UHC emissions, the flame temperature must be kept above 2500 ° F. Therefore, to simultaneously lower emissions of the NO _x and CO and UHC must keep the flame temperature between 2500 ° F and 2800 ° F.

In the design of the premixed combustion apparatus, the air flow rate and the fuel flow rate are such that the flame temperature is about 28 when the engine is at full power.
Adjusted to 00 ° F. The fuel flow rate is reduced as the required engine power is reduced. The air flow rate through the gas turbine engine also decreases as the output decreases, but decreases at a slower rate than the fuel flow rate. Therefore, the flame temperature decreases as the power decreases. If the flame temperature is 2500
If it falls below ° F, CO and UHC emissions will increase. Therefore, the fuel flow to various parts of the combustor must be completely shut off to increase the fuel flow and flame temperature in the combustor zone maintaining the fuel flow and flame (but below 2800 ° F). .. This method is called fuel staging.

It is important to aerodynamically shield the entire flame holding area from the combustor area that shields the fuel and flame. Maintaining the proper air-fuel mixture in this manner allows the flame temperature in the combustor utilization zone to be maintained between 2500 ° F and 2800 ° F. Further, by keeping the velocity of the air-fuel mixture flowing through the premixing tube at a sufficiently high value, it is possible to prevent the flame from staying at the upstream end of the premixing tube in the case of, for example, a momentary flashback. is important. In this way, if the air flow through the gas turbine is momentarily interrupted due to compressor stall and flashback into the premix tube occurs,
The retrograde flame is blown out as soon as the air flow through the gas turbine returns to normal levels, so no premixing tube damage occurs.

FIG. 1 shows a premix combustor 2. The combustor 2 includes an outer shell 4, a diffuser 5, a liner 6, and a combustion chamber 7
, The premixing tubes 8, 10, 12, 16, 18, 20, the pilot nozzle 14, the inflowing air 22, and the fuel table 50.
And fuel manifolds 24, 26, 28, 30, 32, 3
4 and 36 are included. Outer shell 4 is preferably made of any suitable steel with liner 6 disposed therein.
Liner 6 is preferably an International Nickel, based in Huntington, West Virginia.
It is made of Hastelloy (trademark) X manufactured by International Nickel Company. A thin refractory ceramic coating 120 (FIG. 5) is applied to the inner surface of the liner 6 by conventional coating techniques such as plasma spraying.
This coating is preferably of partially stabilized zirconia,
The thickness is about 0.030 inch. The coating 120 helps protect the liner 6 from the deleterious effects of heating due to combustion occurring within the combustion chamber 7. The liner 6 surrounds the combustion chamber 7, in which combustion of fuel and air 22 takes place.

A staggered array of premixed combustor tubes 8, 10, 12, 16, 18, along the wall of liner 6 in liner 6.
20 are arranged. Tubes 8, 10, 12, 16, 1
8 and 20 are located in the combustion chamber 7 and significantly reduce the possibility of an increase in CO and UHC with a reduction in engine power. FIG. 2 shows the specific structure of the combustor tubes 8, 10, 12, 16, 18, 20. The tube of FIG. 2 is designated by the reference numeral 8, but tube 1
It should be understood that 0, 12, 16, 18, 20 are effectively similar structures. Tube 8 preferably has a diameter of 1.50
It is 15 inches long by inches and has an extension 66 with a diameter of 0.25 inches. Tube 8 has a length to diameter ratio of about 10
It is to be understood that otherwise the mixing of air and fuel before entering the combustion chamber 7 cannot be made good. Tube 8 is preferably made of Hastelloy X as described above. Tube 8 also has about 36 holes 6
8 and these holes are preferably 0.375 inches in diameter and are formed in tube 8 by conventional hole forming techniques, such as metal stamping. Hole 68 allows air 22 to enter tube 8. The tube 8 also has threads 64 on the extension 66. The extensions 66 can be of varying lengths to provide a suitable staggered tube arrangement, with tubes 8, 20 having the longest extensions 66 and tubes 12, 16 having the shortest extensions 66 (FIG. 1). ).

As shown in FIG. 1, the tubes 8, 10, 12, 1
The screws 64 of 6, 18, and 20 are screwed to the fuel table 50. Fuel platform 50 is preferably made of any metallic material, such as steel. The inlet passages 52, 54, 5 in the fuel platform 50
6, 58, 60, 62 are arranged and the tubes 8, 1 respectively.
It is connected to the screw 64 of the extension 66 of 0, 12, 16, 18, 20. Conventional manifold inlets 38, 40, 4
2, 44, 46 and 48 are respectively connected to the inlet passages 52, 54, 56, 58, 60 and 62 by conventional connectors. Conventional fuel manifolds 24, 26, 28, 3
2, 34 and 36 are connected to manifold inlets 38, 40, 42, 44, 46 and 48, respectively, by conventional connectors.

FIG. 3 shows a fuel control system 80. The fuel control system 80 includes fuel manifolds 24, 26, 28, 30, 3
2, 34, 36 and the introduction pipe lines 81, 82, 84, 86,
88, 90, 92 and valves 94, 96, 98, 99, 10
0, 102, 104, conduit lines 106, 110, control valve 112, line 114, shutoff valve 116, and fuel introduction line 118. In particular, gaseous fuel from a fuel source, preferably a natural gas source (not shown), enters fuel inlet line 118 and passes through shutoff valve 116 to line 114. The fuel in line 114 goes to control valve 112. Fuel exiting control valve 112 passes through conduit 106 to valves 94, 9
6, 98, 99 and through conduit 110 to valve 10
Go to 0, 102, 104. The fuel then flows into valves 94, 9
6, 98, 99, 100, 102, 104 to respective introduction lines 81, 82, 84, 86, 88, 90, 92.
Can flow into. Finally, the introduction lines 81, 82, 84, 8
Fuel from 6, 88, 90, 92 is fuel manifold 2
4, 26, 28, 30, 32, 34, 36 and finally tubes 8, 10, 12, 16, 18, 20 and pilot nozzle 14.

FIG. 4 shows the tubes 8, 10, 12, 16, 18, 2.
How to arrange 0 as a circular tube bundle is shown. In detail,
Preferably, 10 tubes 8 (reference numerals 8a to 8j), 10 tubes 20 (reference numerals 20a to 20j) and 7 tubes 10 (reference numeral 1)
0a to 10g) and seven tubes 18 (reference numerals 18a to 18g)
And 4 tubes 12 (reference numerals 12a to 12d) and 4 tubes 16
(16a-16d) are provided with the nozzle 14 arranged in the tube bundle. As shown, the tubes 8a-8j and the tubes 20a-20j are arranged on the outer annulus of the tube bundle.
Also, tubes 10a-10g and tubes 18a-18g are located in the intermediate annulus and include tubes 12a-12d and tubes 16a-16d.
Are located in the innermost annulus. Finally, nozzle 1
4 is arranged almost in the center of the tube bundle.

The pipes 8a-8j are connected to the inlet passage 52a,
Preferably, the inlet passages 52a are semi-circular closed and the individual outlets are connected to respective extensions 66 of the tubes 8a-8j,
A fuel introduction device from a gas source (not shown) to each of the pipes 8a to 8j is configured. The pipes 20a to 20j are the pipes 8a to 8j.
Is connected to the inlet passage 62a in substantially the same manner as the connection between the inlet passage 52a. Similarly, tubes 10a-10g and tubes 18a-18g, respectively, are substantially identical to the connections between tubes 8a-8j and inlet passage 52a in the respective inlet passages 54a, 6a.
0a. Finally, the pipes 12a-12d and the pipes 16a-16d are respectively in substantially the same manner as the connection between the pipes 8a-8j and the inlet passage 52a, respectively, the inlet passages 56a, 58.
It is connected to a.

FIG. 5 clearly shows the staggered arrangement of the tubes 8, 10, 12. In particular, the tubes 8, 10, 12 are rigidly attached to the liner 6 by conventional joining techniques, such as welding, and the tubes 8 are
It penetrates deeper into the combustion chamber 7 than 0, and the pipe 10 penetrates deeper into the combustion chamber 7 than the pipe 12. Tubes 8, 1
Although only 0, 12 are shown, it should be understood that the same staggered description applies to tubes 16, 18, 20. As mentioned above, the liner 6 has a heat resistant coating 120 applied to the inner surface of the liner where it forms the combustion chamber 7.
Also, the liner 6 is formed with holes 122, preferably by metal stamping. It should be understood that the liner 6 does not have the coating 120 in the area where the holes 122 are located. This is because the coating 120 does not adhere properly around the holes 122. The holes 122 allow the air 22 to enter the combustion chamber 7 and interact with the nozzle 14.

The cooling wall 7 is provided at a position away from the outer wall of the liner 6.
Two are provided. Wall 72 is preferably made of any suitable refractory stainless steel. Holes 124 are formed in wall 72 by conventional hole forming techniques, such as metal stamping. Air 22 cools the back of liner 6 through holes 124.
Specifically, as the air 22 rushes through the gap between the wall 72 and the liner 6, the velocity of the air causes the wall 72 and the liner 6 to move.
A well-known low pressure region is generated in the space between and. Air is sucked in by this low pressure region, flows through the hole 124, flows along the outer wall of the liner 6, flows out between the wall 72 and the liner 6, and the pipes 8, 10, 12 are arranged in the liner 6. Cool liner 6 near the area. The low pressure created by the holes 124 and the velocity of the air 22 propelling the gap between the wall 72 and the liner 6 cools the liner 6 near the area where the tubes 8, 10, 12 are located within the liner 6. However, it is to be understood that the well-known use of backside convection regenerative cooling is utilized to cool combustion chamber 7 and liner 6 near the area where the combustion products exit combustion chamber 7.

During use of the combustor 2, gas from a natural gas source (not shown) is already being supplied and is flowing through the fuel manifolds 24, 26, 28, 32, 34, 36. Further, the fuel and the air are mixed with the premixing pipes 8, 10, 12, 1
6, 18 and 20 are being premixed and the mixture is preferably about 180 feet per second in tubes 8, 10, 12, 1
It flows through 6, 18, and 20. A velocity of 180 feet per second is also used as the velocity of this mixture because it is necessary to prevent the flame in the combustion chamber 7 from entering the premixing tube and causing flashback. Finally, the air 22 enters the combustor 2 near the exit area of the combustion chamber 7, preferably at about 100-200 feet per second. As the air 22 enters the diffuser 5, the air velocity is controlled by the structure of the diffuser 5 to decrease, and the air 22 is drawn into the tubes 8, 10, 12, 16 ,.
18 and 20 holes 68, wall 72 holes 124 and liner 6
And into the hole 122. Natural gas may also be introduced into the manifold 30 and injected from the nozzle 14 and burned to produce a pilot flame. This pilot flame acts as a standard diffusion flame and the tubes 8, 10, 12, 16, 1
It may help stabilize the premixed combustion from 8, 20. At this point, combustor 2 should operate at 100% of full load operation as shown in row 1 in FIG.

FIG. 6 shows the tubes 8, 10, 12, 16, 18, 2.
The fuel schedule regarding the air-fuel mixture within 0 is shown. In particular, the fuel-air ratio divided by the stoichiometric fuel-air ratio for tubes 8, 10, 12, 16, 18, 20 (this standardized fuel-air ratio is called the equivalence ratio) is the pilot pipe. Diffusion rate from 14 and fuel manifold 24, 2
Together with the percentage of fuel introduced into 6, 28, 32, 34, 36, the proportion of air flowing through tubes 8, 10, 12, 16, 18, 20 and the air distribution and the total amount of air in combustor 2. It is shown. As described above, and as shown in row 1 of FIG. 6, during full load operation, φ8, φ10, φ12, φ1
6, φ18, φ20 are all equal to 0.5, the air flow percentage is 100% and the fuel percentage is also 100%. It should be noted that the air distribution ratio remains substantially constant throughout the reduced load of the combustor 2. If, for example, the combustor 2 is desired to be used at about 70% of its maximum load operation, the driver reduces the fuel flow to 70% of its maximum value. Then, the value of the equivalence ratio in all tubes falls to about 0.35. This is shown in row 2 of FIG.
To operate in the 43% to 70% power range, the inlet guide vanes of the gas turbine are adjusted to reduce the air flow rate. at the same time,
Reduce the fuel flow to keep the equivalence ratio at 0.35. This is shown in row 3 of FIG. To further reduce the power, the valve 104 is first closed to shut off the fuel to the tubes 20a-20j. The equivalence ratio value for the remaining tubes is increased to 0.46 as shown in row 4 of FIG. Then tubes 8, 10,
Reduce fuel flow to 12, 16, 18 until equivalence ratio reaches 0.35. The output of the gas turbine is about 32%. To further reduce power, valve 102 is closed and fuel flow to the remaining tubes is reduced. This is shown in lines 5 and 6 of FIG. In this procedure, the output of the gas turbine is reduced from the maximum load to the minimum load.

The tubes 8, 10, 12 (or 20, 18, 1)
6) is shown as staggered tubes. This way
The air flowing from tubes 8 (or 20) during partial load operation in which no fuel is supplied to tubes 8 (or 20)
Since it does not interact with the air-fuel mixture from (or 16, 18), it does not blow out the flame to generate a large amount of CO and UHC. Similarly, when the fuel to tube 10 (or 18) is shut off, the air from this tube does not blow out the flame from tube 12 (or 16).

FIG. 7 shows another embodiment of the present invention. 1 and 7 represent the same parts. FIG. 7 shows a premixed liquid fuel combustor 2. In detail, liquid fuel, preferably #
2 Fuel oil is supplied to the fuel valve 150 by a conventional device (not shown).
Pumped to. Liquid fuel then flows from control valve 150 to conduits 186, 188, 190, 192, 194, 196.
Through staging valves 172, 170, 168, 18
4, 182, 180 respectively. As mentioned above, when the combustor 2 is initially operated at 100% of its maximum load effect, the valves 172, 170, 168, 184, 18
2, 180 is opened so that fuel is introduced into the conduits 166, 1
64, 162, 183, 176, 174 respectively through liquid fuel manifolds 154, 152, 151, 15
6, 158, 160 respectively. However, in this case, only the air is in the manifolds 24, 26, 28, 3
2, 34, 36 and entrance ways 52, 54, 56, 58, 6
Pass 0,62.

As best shown in FIG. 7A, air is preferably supplied through the inlet passage 62 at a pressure 50% above the typical pressure of 150-600 psi in the combustion chamber 7.
Liquid fuel flows into the inlet passage 62 and is atomized by the high velocity air before being introduced into the tube 20. Liquid fuel conditioning or staging is performed as with gaseous fuels,
It provides a reduced load operation while maintaining a small emission of UHC and CO.

In another embodiment of the invention, nozzle 14 is used to inject a mixture of oil and water to provide dual fuel capability with low NO _x emissions. (Water suppresses the flame temperature.) As shown in FIG.
And a fuel introduction pipe 76, an outlet 78, and an end cap 79. In detail, when burning # 2 fuel oil mixed with water,
This mixture flows from the fuel manifold 130 to the fuel inlet pipe 76.
Where fuel is injected from outlet 78. Since water is mixed with fuel oil, an advantageous relatively low flame temperature is generated in the combustion chamber 7. Preferably, at least 6-12 outlets are attached to the end of tube 76 near end cap 79 by conventional attachment means such as welding. Air is also introduced into the gas introduction pipe 74 through the manifold 30 (FIG. 3). The preferred pressure of the air flowing in the tube 74 is 20% higher than the pressure in the combustion chamber 7,
The pressure in the combustion chamber 7 is preferably 150-600 psi. The interaction of the air in the tube 74 with the fuel flowing out of the outlet 78 produces a spray-like liquid fuel which can burn in the combustion chamber 7. It should be appreciated that if the steam source were readily available, as in a conventional combined cycle gas turbine, then steam could be passed through tube 74 and only unmixed # 2 fuel oil would be passed through tube 76. This way
As the fuel oil exits the outlet 78, it may be atomized by the high velocity steam. This also helps to reduce the flame temperature in the combustion zone 7.

Various other features and various modifications or improvements that will be apparent to those skilled in the art from the above disclosure are of course part of the present invention.

[Brief description of drawings]

FIG. 1 is a side view of a premixed combustion device according to the present invention.

FIG. 2 is a detailed side view of a premix combustor tube.

FIG. 3 is a schematic diagram of a fuel controller and a fuel manifold.

4 is an end view of the premix combustor tube bundle and fuel system taken along line 4-4 of FIG.

FIG. 5 is a detailed side view of the premix combustion system showing the staggered arrangement of the premix combustor tubes and the air-assisted fuel nozzles.

FIG. 6 is a fuel schedule according to the present invention.

FIG. 7 illustrates another embodiment of a fuel controller and fuel manifold. FIG. A is a detailed view of a portion within a dotted line area of the liquid fuel table in the figure.

[Explanation of symbols]

2 premix combustor 5 diffuser 6 liner 7 combustion chamber 8, 10, 12, 16, 18, 20 premix pipe 14 pilot nozzle 24, 26, 28, 30, 32, 34, 36 fuel manifold 52, 54, 56, 58, 60, 62 Inlet passage 66 Premixing pipe extension 68 Hole 72 Cooling wall 74 Gas introduction pipe 76 Fuel introduction pipe 78 Outlet 80 Fuel control device 81, 82, 84, 86, 88, 90, 92 Gas fuel introduction pipe passage 94, 96, 98, 99, 100, 102, 104 Valve 106, 110 Conduit line 120 Heat resistant ceramic coating 122 Hole 124 Hole 151, 152, 154, 156, 158, 160 Liquid fuel manifold 162, 164, 166, 174, 176 , 183 Liquid fuel introduction line

Claims (15)

[Claims] 1. A combustion chamber for combusting a mixture of fuel and air, and a plurality of premixing combustor tubes for premixing the fuel and air before flowing into the combustion chamber. A premix combustor tube having an end and a plurality of holes disposed at the first end and the second end disposed substantially within the combustion chamber, and premixing thereof Fuel introduction means connected to the first end of the combustor tube, air introduction means for introducing air into the premixed combustor tube, and a small discharge amount while maintaining a low flame temperature in the combustion chamber. A combustion device comprising fuel and control means for controlling the air. 2. The combustion chamber comprises an outer wall, an inner wall, and a heat-resistant coating provided over substantially the entire surface of a part of the inner wall.
The combustion apparatus according to claim 1, further comprising: a porous body disposed substantially over the entire surface of the other portion of the inner wall and a portion of the outer wall. 3. The premixing tube comprises a bundle of tubes, the tube bundle being divided into at least three continuous ring groups of tubes, the continuous rings having different diameters and the first ring being a first ring. The combustion device of claim 1, wherein the second ring surrounds the third ring and the second ring surrounds the third ring. 4. The third ring according to claim 3, wherein the first ring is arranged further in the combustion chamber than the second ring, and the second ring is arranged further in the combustion chamber than the third ring. Combustion device. 5. The fuel introducing means includes a fuel source, a valve device, a first fuel guiding means for connecting the fuel source and the valve device, a manifold device, and the fuel guiding means. A combustion system according to claim 1, comprising fuel inflow means connected to the system and second fuel flow means connected to the manifold system to the premix combustor tube. 6. The combustion device of claim 5, wherein the second fuel introducing means includes a liquid fuel manifold device. 7. The combustion apparatus according to claim 1, wherein the air introduction unit includes an air source, a diffuser, and an air transfer unit that substantially connects the air source and the diffuser. 8. The air introducing means includes an air source, a valve device, a first air guiding means connecting the air source and the valve device, a manifold device, and the air guiding means. A combustion system according to claim 1 comprising air inflow means connected to the system and second air diversion means connecting the manifold system to the premix combustor tube. 9. The combustion device of claim 1, wherein the air introducing means includes an air source that provides a significantly higher air velocity to substantially prevent flashback damage to the combustor tube. 10. A liquid fuel introduction means is further provided, said introduction means being disposed substantially inside said third ring and having first and second ends, said first end being said fuel introduction means. Means and said air introducing means and said second
The combustion device of claim 3, wherein the end is located substantially within the combustion chamber. 11. The liquid fuel introducing means comprises a liquid fuel introducing means, an air introducing means for transferring air, and a liquid fuel injecting means connected to the liquid fuel introducing means. The atomized fuel is generated and burned in the combustion chamber by the interaction between the air in the air guiding means and the injected fuel when injected from the injection means.
0 of the combustion device. 12. Further comprising a second wall spaced from and parallel to the outer wall of the combustion chamber and a plurality of holes in a portion of the second wall adjacent the premix combustor tube. The combustion device according to claim 2. 13. A combustion chamber for burning a mixture of fuel and air, a fuel introducing means, an air introducing means, an air auxiliary fuel nozzle device, and the air-fuel mixture before it flows into the combustion chamber. A method for operating a low-emission low-flame temperature combustor having a plurality of premixed combustor tubes and a control means, wherein air is introduced into the combustor by the air introduction means for the combustion chamber and Flowing into the combustor pipe, flowing fuel into the combustor pipe by the fuel introducing means for the combustion chamber, passing fuel and air through the air auxiliary fuel nozzle device, and the air-fuel mixture In the combustion chamber, and controlling the air introducing means and the fuel introducing means so as to produce a small discharge amount and a low flame temperature. 14. The step of controlling the air introducing means and the fuel introducing means closes the fuel introducing means to a predetermined premixed combustor tube and connects the combustor and the combustor tube to each other. 14. The method according to claim 13, comprising maintaining an air flow rate substantially constant, reducing the action of the air introduction means to the combustor tube, and maintaining the fuel flow rate to a predetermined combustor tube substantially constant. Low emissions low flame temperature How to operate a combustor. 15. The combustor has a plurality of holes in a portion of the combustion chamber, the holes being disposed adjacent to the air-assisted fuel nozzle device, and having a second wall in the combustion chamber. 14. A plurality of holes are disposed at a distance from and substantially parallel to and a plurality of holes are disposed in a portion of the second wall and spaced from the holes in the combustion chamber.
A method of operating a low emission, low flame temperature combustor as described, wherein air is directed along said combustor and said combustion chamber and said second
Transporting past the wall, this air creates a vacuum between the second wall and the combustion chamber and the combustor, and
A method further comprising allowing air to flow through the holes in the second wall to cool the combustion chamber and air to flow through the combustion chamber to facilitate combustion of the fuel in the combustion chamber. ..