JP2000074372A - Burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure stability upon low load combustion. SOLUTION: Combustion air is supplied into a case 3, and fuel gas such as urban gas is supplied to a nozzle 20 through a flow rate control valve. Concentric swirlers 36, 37 are disposed downstream a nozzle hole of the nozzle 20. Upon high load combustion the fuel gas is injected from a first nozzle hole 34 of a large diameter portion and from a second nozzle hole 40 of a cone 22, and reaches not only the central swirler 36 but also the surrounding swirler 37 to permit the high load combustion to be performed in a combustion chamber disposed downstream the swirler. The fuel gas injected from the first and second nozzle holes 34, 40 upon the low load combustion where the fuel gas is a low flow rate flows near the axis of the nozzle structure and is guided to the central swirler 36, whereby concentration of the fuel gas in the central swirler 36 is prevented from being lowered to keep a stable combustion state unchanged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner for burning fuel gas which is suitably used as a combustor of a gas turbine and which is preferably used in connection with a heating furnace or the like.

[0002]

2. Description of the Related Art A typical prior art in which the combustion load can be changed and adjusted is to install a plurality of burners and selectively operate each of these burners to change the amount of combustion.

In this prior art, since each burner is selectively operated, the temperature of the exhaust gas fluctuates, and thus the load of the gas turbine fluctuates.

One proposed burner which solves this problem is provided with a plurality of air introduction holes separated from each other by a partition at a central portion and a peripheral portion outside the central portion to supply the air to the central portion and the peripheral portion. The flow rate of the fuel gas is controlled such that the air ratio at the center is smaller than the air ratio at the periphery. The new problem of this burner is that when the flow rate of the fuel gas is controlled at a low load, the flame in the peripheral portion disappears or the combustion becomes unstable, and it is difficult to control the flow rate.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a burner capable of smoothly changing a combustion load and achieving stable combustion at a low load.

[0006]

According to the present invention, there is provided a case for forming a combustion air flow path to which combustion air is supplied, and a fuel gas is disposed in the combustion air flow path. A nozzle body having a nozzle hole to be ejected, and a plurality of swirlers disposed downstream of the nozzle hole in a flow direction of the combustion air in the combustion air flow path, wherein each swirler is located near the nozzle hole. And swirlers, which are separated from each other by a partition member extending along the flow direction of the combustion air, in a region farther from the nozzle hole than a region near the region. Burner.

According to the present invention, a combustion air flow path is formed in the case of the burner, and the combustion air is supplied thereto at a predetermined constant flow rate, for example. A nozzle body having a nozzle hole for ejecting fuel gas is arranged within the combustion air flow rate, and a plurality of swirlers are arranged downstream of the nozzle hole of the nozzle body in the flow direction of the combustion air. You. The swirlers serve to swirl and mix the combustion air and fuel gas, for example, about the axis of each swirler. These swirlers are respectively arranged in a region near the nozzle hole and a region far from the nozzle hole. Each swirler is partitioned by the partition member, so that the gas including the combustion air and the fuel gas does not mix between the swirlers.

At the time of high load combustion, a large flow rate of fuel gas is supplied to the nozzle body. Therefore, swirlers disposed in the near area and the far area contain combustion air and fuel gas, respectively. Supplied. Thus, stable combustion is performed in the combustion chamber on the downstream side of the swirler.

By adjusting the flow rate of the fuel gas to a small value, the combustion load can be smoothly reduced, and a large load fluctuation does not occur. This is important for keeping the rotation speed of the turbine constant, especially when the present invention is implemented as a combustor of a gas turbine.

When the flow rate of the fuel gas supplied to the nozzle body is reduced, the fuel gas from the nozzle hole mainly flows to the swirler arranged in the above-mentioned neighboring area, and is arranged in the far away area. It does not reach the swara. In the swirler in the nearby area, the concentration of the fuel gas is high, the air ratio is kept low, and therefore a stable combustion state can be maintained. In this way, the range of adjustment of the amount of combustion can be widened,
The flammability limit can be extended, and the turndown ratio can be increased.

Further, according to the present invention, the nozzle body is connected to a large-diameter portion in which a plurality of first nozzle holes are formed at intervals in a peripheral wall, and a downstream end of the large-diameter portion for combustion air. And a conical portion that is formed in a tapered shape toward the downstream of the working air and has a plurality of second nozzle holes formed at intervals on a peripheral wall.

According to the present invention, the nozzle body includes, for example, a straight cylindrical large-diameter portion and a hollow straight-cone-shaped pyramid portion connected to the large-diameter portion. A plurality of first and second nozzle holes are respectively formed in the portion.
In the state where the flow rate of the fuel gas supplied to the nozzle body is set to be large in order to increase the combustion load, the first and second
The fuel gas ejected from both of the nozzle holes is swirled and mixed with the combustion air by the swirlers arranged in the near region and the far region as described above, and the combustion is performed.

At the time of low load combustion, the flow rate of the fuel gas supplied to the nozzle body is reduced, so that the flow rate of fuel gas ejected from the first nozzle hole is lower than at the time of high load combustion. The fuel gas from one nozzle hole has a reduced gas ejection speed, and flows near the axis of the nozzle body, that is, near the peripheral wall surface of the large diameter portion. Fuel gas is also ejected from the second nozzle hole formed in the tapered cone, and flows toward the axis of the nozzle body. Therefore, it is possible to keep the concentration of the fuel gas high in the swirler in the vicinity area, reduce the air ratio, and maintain a stable combustion state. In this way, a region where the decrease in the concentration of the combustion air from the swirler in the vicinity region is suppressed downstream of the swirler of the case is maintained, and stable low-load combustion can be maintained.

Further, according to the present invention, the large diameter portion is formed to be thick,
Thus, the first nozzle hole is formed in a choke shape.

According to the present invention, the large-diameter portion is formed to be relatively thick, so that the first nozzle hole is a choke, that is, the flow path of the first nozzle hole is smaller than the flow path cross-sectional area of the first nozzle hole. And the first nozzle hole can be elongated. As a result, the fuel gas ejected from the outlet end of the first nozzle hole is ejected radially outward of the nozzle body along the axis of the first nozzle hole, and the fuel gas goes away during high load combustion. The swirler in the region is reliably reached, and in the combustion chamber downstream of the swirler, stable combustion can be achieved with the concentration of fuel gas as uniform as possible.

Further, the present invention is characterized in that the axis of the first nozzle hole has an angle θ1 of 80 to 150 degrees with respect to the axis of the nozzle body.

Further, the present invention is characterized in that the axis of the second nozzle hole has an angle θ2 of 10 to 80 degrees with respect to the axis of the nozzle body.

According to the present invention, the angles θ1 and θ2 of the axes of the first and second nozzle holes are set as described above, thereby maintaining stable combustion in each of the high load and low load combustion states. be able to. If the angle θ1 of the axis of the first nozzle hole is selected to be less than 80 degrees and more than 150 degrees,
At the time of high load combustion, the fuel gas cannot reach the swirler in the area away from the first nozzle hole, and the distribution of combustion air and the fuel gas is made as uniform as possible in the combustion chamber downstream of the swirler. Can not be achieved.

If the angle θ2 of the axis of the second nozzle hole is selected to be less than 10 degrees, the area where the fuel gas is ejected from the second nozzle hole is in a narrow range in the above-mentioned area, The uniform mixing of the combustion air and the fuel gas may be difficult due to the swirler in the vicinity area. When the angle θ2 of the axis of the second nozzle hole exceeds 80 degrees, it becomes difficult to inject the fuel gas to the swirler only in the above-described area during low load combustion, and it is not possible to maintain a stable combustion state .

Further, in the present invention, the nozzle body is characterized in that a plurality of nozzle holes are formed at intervals in a circumferential direction on a peripheral wall of a cylindrical body whose downstream end of the combustion air is closed. I do.

According to the present invention, in the nozzle body, for example, as shown in FIG.
Only one nozzle hole 34 is formed, and the cone 22 may be omitted, thereby simplifying the configuration. When the flow rate of the fuel gas supplied to the nozzle body is adjusted to be large or small according to the load, the flow rate of the fuel gas from the nozzle hole 34 changes. It becomes smaller and flows closer to the axis of the nozzle body,
By maintaining the fuel gas concentration of the swirler arranged in the vicinity area, the combustion state can be stably maintained.

Further, the present invention is characterized in that a portion of the cylinder downstream of the nozzle hole on the downstream side of the combustion air is tapered toward the downstream of the combustion air.

According to the present invention, as shown in FIG. 7 to be described later, the portion downstream of the nozzle hole 34 of the cylindrical body 21 is formed into a tapered shape to form the conical portion 22. A flow of fuel gas flows near the axis of the nozzle body and, therefore, from the nozzle hole 34 to the tapered portion 22, thereby preventing a decrease in fuel gas concentration with the swirler in the nearby area and keeping the air ratio small. In addition, it is possible to easily maintain a stable combustion state at a low load.

The present invention is also characterized in that the axis of the nozzle hole has an angle θ1 of 80 to 150 degrees with respect to the axis of the nozzle body.

According to the present invention, the angle .theta.1 of the axis of the nozzle hole is selected in the range of 80 to 150 degrees in the same manner as described above. The combustion air can also reach the swirler arranged in the region, and a combustion state as uniform as possible between the combustion air and the fuel gas can be achieved in the combustion chamber downstream of the swirler.

Further, the present invention is characterized in that the swirler is formed concentrically with an axis extending from the axis of the nozzle body.

In accordance with the present invention, the swirler is formed concentrically, and the central swirler may be, for example, annular, such as a circular axis, as described below in connection with FIGS. May be provided, and the peripheral swirler arranged radially outward of the central swirler is formed in an annular shape. Each of such concentric swirlers is partitioned by, for example, an annular partition member, and the gas of each swirler does not mix. At the time of high load combustion, the fuel gas reaches not only the central swirler but also the peripheral swirler. At the time of low load combustion, the fuel gas concentration of the central swirler is maintained, and a stable combustion state can be maintained.

According to the present invention, the swirler has a first swirler having an axis on the extension of the axis of the nozzle body and an imaginary circle having a center on the extension of the axis of the nozzle body. It has a plurality of second swirlers arranged adjacent to each other in the circumferential direction of the virtual circle.

According to the present invention, as will be described later with reference to FIGS. 8 and 9, a plurality of second swirlers are disposed radially outward of the central one swirler and circumferentially adjacent thereto. Is done. At the time of high load combustion, the fuel gas reaches not only the first swirler but also the second swirler, and combustion is performed. At the time of low load combustion, stable combustion without lowering the fuel gas concentration in the first swirler. The state can be maintained, and at this time, the concentration of the fuel gas has decreased in the second swirler.

Further, the present invention is characterized in that the combustion air is supplied at a predetermined constant flow rate and a flow control valve for controlling the flow rate of the fuel gas supplied to the nozzle body is provided.

According to the present invention, the flow rate of the combustion air is maintained at a predetermined constant value, and the flow rate of the fuel gas is controlled by the flow control valve, whereby the combustion load is controlled over a wide range by a relatively simple operation. be able to.

[0032]

FIG. 1 is a sectional view showing a partial configuration of a burner 1 according to an embodiment of the present invention, and FIG. 2 is a sectional view showing an entire configuration of the burner 1. As shown in FIG. . Referring to these drawings, the present burner 1 is used, for example, as a combustor of a gas turbine, and the gas turbine is implemented in connection with a cogeneration system. The cogeneration system is used for performing district power generation and district heating / cooling. To be put to practical use. The combustion gas from the outlet cylinder 60 of the burner 1 is supplied to the turbine 62 and
Is driven. The air compressor 9 is rotationally driven by the turbine 62.

The combustion air from the air compressor 9 is supplied to the combustion air flow passage 8 in the case 3 by pressure. The case 3 includes a diffuser 2 and a downstream side of the combustion air flowing direction 11 in the diffuser 2 (rightward in FIGS. 1 and 2).
And a straight cylindrical combustion case 6 formed at the end of the combustion case. A cylindrical holding case 4 is attached to the diffuser 2 by a flange 5. A combustion case 6 is arranged in the holding case 4.

A nozzle body 20 is disposed in the combustion air passage 8 of the case 3. A fuel gas supply device 27 supplies a fuel gas such as city gas to the nozzle body 20. The fuel gas supply device 27 includes a gas supply source 25.
A flow control valve 29 for controlling the flow rate of the fuel gas from the gas supply source 25; and a fuel gas supply pipe 28 for supplying the fuel gas from the flow control valve 29 to the nozzle body 20 through the diffuser 2. Including.

The nozzle body 20 basically has a large-diameter cylindrical portion 21, a hollow straight-cone cone 22 connected to the downstream end of the large-diameter combustion air, and a cone 22. And a mounting portion 23 connected to the downstream end of the combustion air.
And a common axis. Cone 22
Is tapered toward the downstream side of the combustion air. The mounting portion 23 is coaxially fixed to the swirler device 26. The outer peripheral portion of the swirler device 26 is fixed to the inner peripheral surface of the cylindrical body 30. The tubular body 30 surrounds the nozzle body 20 and extends upstream of the nozzle body 20 in the combustion air flow direction 11 (to the left in FIGS. 1 and 2). The cylinder 30 is connected to the outward flange 42. The base end of the combustion cylinder 14 is fixed to the outward flange 42. Axis 2 of nozzle body 20
4, the axis of the cylinder 30, the combustion cylinder 14, and the combustion case 6 are present. An annular space 51 is formed between the combustion case 6 and the combustion cylinder 14. A plurality of (for example, six) rows of air holes 52 are formed in the combustion cylinder 14 at intervals in the flow direction 11 of combustion air, and dilution holes 53 are provided downstream of the air holes 52 for combustion air. Is formed. The air holes 52 in each row are formed at intervals in the circumferential direction. A combustion chamber 31 is formed in the combustion cylinder 14. An ignition plug 58 is provided near the swirler device 26 of the combustion cylinder 14. A leading cylinder 60 is provided at the tip of the combustion cylinder 14. The lead-out cylinder 60 is formed in a tapered shape,
It is supported by a support plate 64.

FIG. 3 is an enlarged sectional view of the nozzle body 20. A coaxial fuel gas flow path 32 is formed in the nozzle body 20. In the large diameter portion 21, a plurality of first nozzle holes 34 are formed in the peripheral wall 33 at intervals in the circumferential direction. The peripheral wall 33 of the large diameter portion 21 is formed thick. Therefore, the first nozzle hole 34 is longer than the flow path cross-sectional area and is formed in a choke shape. Therefore, the fuel gas supplied to the flow path 32 is jetted along the axis 35 of the first nozzle hole 34. The axis 35 of the first nozzle hole 34 has an angle θ1 with respect to the axis 24 of the nozzle body 20. Angle θ1
Is selected at 80 to 150 degrees. Although the axes 24, 35 may lie in one plane, the axis 35 may intersect the plane containing the axis 24.

The large diameter portion 21 of the nozzle body 20 is provided with a plate-like collision member 67 extending radially outward as shown in FIG. When the combustion air collides with the collision member 67, the fuel gas from the first and second nozzle holes 34 and 40 is not undesirably hindered by the combustion air, and has an appropriate flow rate according to the combustion load. Can be squirted. In another embodiment of the present invention, the impact plate 67
May be omitted. A radially outer peripheral portion 68 of the collision plate 67 protrudes toward the upstream side in the combustion air flow direction 11. Thereby, the first and second nozzle holes 3
It is possible to reliably prevent the ejection of the fuel gas from 4, 40 from being disturbed by the flow of the combustion air.

The swirler device 26 has a central annular swirler 36 surrounding the mounting portion 23 of the nozzle body 20 and a peripheral swirler 37 formed annularly around the outer periphery of the swirler 36. An annular partition member 38 is interposed between the 37. Thus, the swirlers 36 and 37 are connected to the nozzle body 2
It is formed concentrically with an axis on the extension of the zero axis 24.

When the angle θ1 of the axis 35 of the first nozzle hole 34 is less than 80 degrees, the first nozzle hole 34 is
The fuel gas ejected from the fuel tank surely reaches the vicinity of the surrounding swirler 37 and the partition member 38 and cannot be supplied. If the angle θ1 exceeds 150 degrees, the fuel gas from the first nozzle hole 34 cannot reliably reach the vicinity of the surrounding swirler 37 and the partition member 38 during high load combustion. The length of the first nozzle hole 34 is
For example, it may be 5 to 10 mm or 7 mm. As the peripheral wall 33 is made thicker and the first nozzle hole 34 is elongated, the fuel gas ejected from the first nozzle hole 34 is rectified and ejected at the time of high load combustion, and the peripheral gas is ejected as described above. Is supplied to the vicinity of the swirler 37.

A plurality of second nozzle holes 40 are formed in the peripheral wall 39 of the cone 22 at intervals in the circumferential direction. The axis 41 of the second nozzle hole 40 has an angle θ2 with respect to the axis 24 of the nozzle body 20, and the angle θ2 is selected from 10 to 80 degrees. If the angle θ2 is less than 10 degrees, the second nozzle hole 4
It is not sufficient for the fuel gas ejected from 0 to swirl and mix uniformly with the combustion air to the central swirler 36, so that a stable combustion state during low load combustion cannot be maintained. When the angle θ2 exceeds 80 degrees, the fuel gas from the second nozzle hole 40 is not guided to the central swirler 36 at the time of high load combustion and low load combustion, and the concentration of the fuel gas at the central swirler 36 decreases, Combustion becomes unstable. The axis 41 of the second nozzle hole 40 is
May lie in one plane containing the axis 24 of
This axis 41 may intersect the plane. Cone 2
The second peripheral wall 39 may be thick like the above-mentioned peripheral wall 33 of the large-diameter portion 24, but may be thin. The fuel gas passage 32 is closed at an end 43 on the downstream side.

FIG. 4 is a front view of the swirler device 26, and FIG. 5 is a partially developed view of the swirler device 26 in FIG. The central swirler 36
A plurality of swirling vanes 45 arranged circumferentially at intervals between the partition member 38 and the cylindrical portion 44 and extending in the radial direction are fixed. The mounting portion 23 of the nozzle body 20 is fitted and fixed to the cylindrical portion 44. The peripheral swirler 37 has a configuration in which a turning blade 47 extending in the radial direction is fixed between the partition member 38 and the cylindrical portion 46 at intervals in the circumferential direction. The swirling blade 47 is configured similarly to the above-described swirling blade 45. The swirl vane 45 has, for example, about 45 degrees with respect to the axis 24, and is formed to be curved as shown in FIG.

FIG. 6 is a circumferential development of the central swirler 36 in another embodiment of the present invention. In this embodiment, the swirling blade 45a is formed in a flat plate shape, and the same applies to the surrounding swirler 37. The length L1 of the swirler 26 along the axis 24 may be, for example, 10 mm. During operation of the gas turbine, the turbine 62
Is rotated at a substantially constant rotational speed, and thus the flow rate of the combustion air supplied from the air compressor 9 to the combustion air flow path 8 is kept constant.

When performing high-load combustion with the burner 1 in order to increase the output of the gas turbine, the flow control valve 2
9 is increased, and the flow rate of the fuel gas is increased. As a result, the fuel gas ejected from the first nozzle hole 34 of the nozzle body 20 reaches the peripheral swirler 37 as shown by reference numeral 52 in FIG. Reach nearby. Further, the second nozzle hole 4
The fuel gas ejected from zero is guided to the central swirler 36 as indicated by reference numeral 54. Thus Swara 3
The combustion air and fuel are swirled and mixed by 6, 37, and stable combustion is performed in the combustion chamber 31 in the combustion cylinder 14 downstream of the swirler device 26.

At the time of low load combustion, the flow rate of the fuel gas supplied by the flow control valve 29 is reduced to a small value. As a result, the fuel gas ejected from the first nozzle hole 34 of the nozzle body 20 flows toward the axis 24 of the nozzle body 20 as indicated by reference numeral 56 in FIG. As a result, only the vicinity of the central swirler 36 is reached and the peripheral swirler 37 is not reached. The fuel gas ejected from the second nozzle hole 40 is denoted by reference numeral 57.
The fuel gas is supplied closer to the axis 24 than the fuel gas from the first nozzle hole 34. In this way, the concentration of the fuel gas in the central swirler 36 is maintained as in the case of high load combustion, and the air ratio can be kept low. Therefore, during low load combustion, a stable combustion state can be maintained, and the combustion limit can be extended.

FIG. 7 is a partial sectional view of one embodiment of the present invention. FIG. 7 corresponds to the configuration of FIG. 1 described above. Other configurations of the embodiment shown in FIG. 7 are the same as those of the above-described embodiment, and the corresponding portions are denoted by the same reference characters or denoted by the suffix a. It should be noted that in this embodiment, the large diameter portion 21 of the nozzle body 20a is
A plurality of first nozzle holes 34 are formed at intervals in the circumferential direction, and the cone portion 22 has the second nozzle holes 34 in the above-described embodiment.
No nozzle hole 40 is formed. The large-diameter portion 21 of the nozzle body 20a is a straight cylindrical body in which the downstream end 83 of the combustion air is closed. The cone portion 22, which is a portion of the large diameter portion 21 on the downstream side (right side in FIG. 7) of the combustion air from the nozzle hole 34, continues, and the cone portion 22 is located downstream of the combustion air as described above. It becomes tapered as it becomes.

At the time of high load combustion, the fuel gas ejected from the nozzle hole 34 is supplied so as to reach the vicinity of the partition member 38 as indicated by reference numeral 65. Therefore, the fuel gas indicated by the reference numeral 65 is supplied to the surrounding swirler 37.
And swirl guided over both and the central swirler 36,
Mixed.

At the time of low load combustion, the fuel gas from the nozzle hole 34 is supplied to the central swirler 3 as indicated by reference numeral 66.
6. This prevents the concentration of the fuel gas in the swirler 36 from lowering during low-load combustion, and can maintain a stable combustion state. Since the cone portion 22 is provided downstream of the large diameter portion 21, the fuel gas ejected from the nozzle hole 34 can be smoothly guided to the central swirler 36.

FIG. 8 is a front view of a swirler device 26b according to another embodiment of the present invention, and FIG. 9 is a longitudinal sectional view of the swirler device 26b shown in FIG. In this embodiment,
Similar to the previous embodiment, corresponding parts are denoted by the same reference numerals. It should be noted that in this embodiment, a first swirler 45b having an axis is provided on an extension of the axis 24 of the nozzle body 20 in the swirler device 26b, and a plurality (six in this embodiment) of the first swirler 45b is provided around the first swirler 45b. 2 swirls 47
b is arranged. The second swirler 47b has an axis 7 on an imaginary circle 69 centered on the extension of the axis 24 of the nozzle body 20.
Has zero. The second swirler 47b is arranged adjacent to the virtual circle 69 in the circumferential direction. First and second swirlers 45
b, 47b are individually partitioned by right and cylindrical partition members 71, 72, and accordingly, each swirler 45b,
The gases of 47b do not mix with each other. Further, the space between the swirlers 45b and 47b is
Closed with. The swirler device 26b is fixed to a cylinder 74 surrounding the outer periphery of the second swirler 47b.
4 is fixed to the inner peripheral surface of the cylindrical body 30 in FIG. Other configurations in the embodiment shown in FIGS. 8 and 9 are the same as those in the above-described embodiment.

FIG. 10 is a front view of a swirler device 26c according to still another embodiment of the present invention, and FIG. 11 is a cross-sectional view of the swirler device 26c shown in FIG. 10 as viewed from XI-XI. In this embodiment, the swirler 75 is arranged in a region near the nozzle hole 34c of the nozzle body 20c, and the swirlers 76 to 78 are arranged in a region farther from the nozzle hole 34c than the neighboring region. You. Each of these swirlers 75 to 78 is provided with a partition member 7 similarly to the above-described embodiment.
9 and 80, and are closed by a shielding plate 81. During high load combustion, all swirls 75
To 78 are supplied with fuel gas from the nozzle holes 34c. At the time of low load combustion, fuel gas is supplied from the nozzle hole 34c only to the swirler 75 in the nearby area.

According to the experiment of the present inventor, in the embodiment of FIGS. 1 to 6, the flow rate of the combustion air is 700 m ³ /
It was confirmed that the turndown ratio could be improved to 20: 1 when H was set to 350 ° C. and city gas was used as the fuel gas.

FIG. 12 is a perspective view of a part of a gas turbine using the burner 1 according to one embodiment of the present invention. The combustion gas from the outlet cylinder 60 is supplied to the turbine 6 of the gas turbine.
2 is injected. A plurality (for example, six) of burners 1 are arranged at intervals in the circumferential direction of the virtual circle 63. The turbine 62 is a so-called axial flow turbine.

FIG. 13 is a partial sectional view of another embodiment of the present invention. Combustion gas from the single burner 1 is supplied to the centrifugal turbine 83 through the outlet tube 84.
Other configurations are the same as those of the above-described embodiment.

The present invention can be implemented not only in connection with a gas turbine, but also in a wide range in connection with a heating furnace, a boiler, and the like.

[0054]

According to the first aspect of the present invention, the swirler is disposed in a region near the nozzle hole and in a region away from the nozzle hole, and each swirler is partitioned by the partition member. Therefore, the gas including the combustion air and the fuel gas does not mix between the swirlers. At the time of high load combustion, the flow rate of the fuel gas is large. In this state, the fuel gas is supplied not only to the swirler arranged in the area near the nozzle hole but also to the swirler arranged in the far away area, and thus the swirler is provided. In the downstream combustion chamber, stable combustion is performed in a uniform premixed state of the combustion air and the fuel gas. Thus, low NOx combustion can be ensured. By controlling the flow rate of the fuel gas, it is possible to smoothly change the combustion gas.

At the time of low load combustion, the flow rate of the fuel gas is small, and the fuel gas from the nozzle hole mainly concentrates on the swirler arranged in a region near the nozzle hole. As a result, the concentration of the fuel gas in the swirler in the vicinity thereof can be maintained, and thus stable combustion during low load combustion can be ensured. Therefore, the adjustment range of the combustion amount can be widened, the flammability limit can be expanded, and the turndown ratio can be increased. Further, the flow rate of the fuel gas may be changed and adjusted according to the load combustion amount, and the control operation is simple.

According to the present invention, a plurality of first and second nozzle holes are respectively formed in the large diameter portion and the cone portion. In a state where the flow rate of the fuel gas supplied to the nozzle body is set to be large in order to increase the combustion load, the first
The fuel gas ejected from the nozzle hole is guided to swirlers respectively disposed in the near area and the far area, and the fuel gas ejected from the second nozzle hole is guided to the nearby area. In this way, the swirler swirls and mixes with the combustion air to perform combustion.

At the time of low load combustion in which the flow rate of the fuel gas supplied to the nozzle body is adjusted to a small value, the flow rate of the fuel gas ejected from the first nozzle hole is greatly reduced. It flows along the vicinity of the peripheral wall surface of the large diameter portion of the body, and flows toward the axis of the nozzle body together with the fuel gas ejected from the second nozzle hole provided in the cone. Thus, the concentration of the fuel gas in the swirler in the vicinity area can be kept high, the air ratio can be reduced, and a stable combustion state can be maintained.

According to the third aspect of the present invention, since the large diameter portion of the nozzle body is formed to be thick and the first nozzle hole is formed in a choke shape, the flow path cross-sectional area of the first nozzle hole is reduced. In comparison, the first nozzle hole can be formed elongated by making the flow path of the first nozzle hole longer. As a result, the fuel gas ejected from the outlet end of the first nozzle hole is ejected radially outward of the nozzle body along the axis of the first nozzle hole, and the fuel gas goes away during high load combustion. The swirler in the region is reliably reached, and in the combustion chamber downstream of the swirler, stable combustion can be achieved with the concentration of fuel gas as uniform as possible.

According to the present invention as set forth in claims 4 and 5,
Since the angles θ1 and θ2 of the axes of the first and second nozzle holes are appropriately set, stable combustion can be maintained in each of the high load and low load combustion states.

According to the sixth aspect of the present invention, as shown in FIG. 7, the nozzle body is circumferentially spaced from the peripheral wall of the cylindrical body 21 whose downstream end of the combustion air is closed. When the flow rate of the fuel gas supplied to the nozzle body is adjusted to be large or small according to the load,
The flow rate of the fuel gas from the nozzle hole changes, and during low load combustion, the flow rate of the fuel gas from the nozzle hole decreases, maintaining the fuel gas concentration of the swirler arranged in the vicinity area, and changing the combustion state. It can be kept stable.

According to the seventh aspect of the present invention, the portion 22 downstream of the nozzle hole 34 of the cylindrical body 21 is tapered as shown in FIG. Is discharged from the nozzle hole 34 to the tapered portion 22.
Therefore, it is possible to easily prevent a decrease in the concentration of the fuel gas due to the swirler in the vicinity area, keep the air ratio small, and maintain a stable combustion state at a low load.

According to the present invention, since the angle θ1 of the axis of the nozzle hole 34 is selected within a proper range, not only the near region but also the far region during high load combustion. The combustion air can reach the swirler disposed in the swirler, and a combustion state as uniform as possible between the combustion air and the fuel gas can be achieved in the combustion chamber downstream of the swirler.

According to the ninth aspect of the present invention, since the swirler is formed concentrically, the fuel gas reaches not only the central swirler but also the peripheral swirler at the time of high load combustion, and at the time of low load combustion. Thus, the fuel gas concentration of the central swirler is maintained, and a stable combustion state can be maintained.

According to the present invention, during high load combustion, fuel gas reaches not only the first swirler but also the second swirler, and combustion is performed.
Without reducing the concentration of fuel gas in the swirler,
A stable combustion state can be maintained.

According to the eleventh aspect of the present invention, the flow rate of the combustion air is maintained at a predetermined constant value, and the flow rate of the fuel gas is controlled by the flow rate control valve. Can be controlled over a wide range.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a partial configuration of a burner 1 according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an entire configuration of the burner 1 shown in FIG.

FIG. 3 is an enlarged sectional view of a nozzle body 20.

4 is a front view of the swirler device 26. FIG.

FIG. 5 is a section line VV of the swirler device 26 in FIG. 4;
FIG. 5 is a partial circumferential development view as viewed from the side.

FIG. 6 is a circumferential development of a central swirler 36 in another embodiment of the present invention.

FIG. 7 is a partial cross-sectional view of one embodiment of the present invention.

FIG. 8 is a front view of a swirler device 26b according to another embodiment of the present invention.

9 is a longitudinal sectional view of the swirler device 26b shown in FIG.

FIG. 10 is a front view of a swirler device 26c according to still another embodiment of the present invention.

FIG. 11 is a cross-sectional view of the swirler device 26c shown in FIG.
It is sectional drawing seen from XI.

FIG. 12 is a perspective view of a part of a gas turbine using the burner 1 according to one embodiment of the present invention.

FIG. 13 is a partial cross-sectional view of another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 burner 2 diffuser 3 case 4 holding case 5 flange 6 combustion case 8 combustion air flow path 9 air compressor 14 combustion cylinder 20 nozzle body 21 large diameter part 22 cone part 23 mounting part 24, 35, 41 axis 25 gas supply Source 26 Swirler 27 Fuel gas supply 28 Fuel gas feed pipe 29 Flow control valve 30 Cylindrical body 31 Combustion chamber 32 Fuel gas flow passage 33, 39 Peripheral wall 34 First nozzle hole 36, 37 Swirler 38 Partition member 40 Second nozzle Hole 42 Outward flange 44 Cylindrical part 45, 45a, 47 Revolving blade 51 Space 52 Air hole 53 Dilution hole 58 Spark plug 60, 84 Outgoing cylinder 62 Turbine 64 Support plate 67 Collision member 68 Peripheral edge 71, 72, 79, 80 Partition Member 83 Centrifugal turbine

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuo Shimohira 7-44-1 Jindaiji Higashicho, Chofu City, Tokyo Inside the National Institute of Aeronautics and Space Technology (72) Inventor Tsutomu Wakabayashi 4-chome Hiranocho, Chuo-ku, Osaka-shi, Osaka No. 1-2 in Osaka Gas Co., Ltd. (72) Koji Moriya Inventor Koji Morino 4-1-2 in Hirano-cho, Chuo-ku, Osaka-shi, Osaka (72) Inventor Yuji Nakamura Hirano-cho, Chuo-ku, Osaka-shi, Osaka 4-chome 1-2 F-term in Osaka Gas Co., Ltd. (reference) 3K017 AA02 AA03 AC03 AC06 AD03

Claims (11)

[Claims] 1. A case that forms a combustion air flow path to which combustion air is supplied, and a nozzle body that is disposed in the combustion air flow path, has a nozzle hole to which fuel gas is supplied, and ejects the fuel gas. In the combustion air flow path, a plurality of swirlers disposed downstream of the nozzle hole in the flow direction of the combustion air, each swirler is a region near the nozzle hole and a region near the nozzle hole And a swirler separated by a partition member extending along the direction in which the combustion air flows, and a swirler arranged separately in a region away from the nozzle hole. 2. The nozzle body is connected to a large-diameter portion in which a plurality of first nozzle holes are formed at intervals in a peripheral wall, and a downstream end of the large-diameter portion for combustion air. The burner according to claim 1, further comprising: a conical portion that is formed in a tapered shape toward the downstream side and has a plurality of second nozzle holes formed at intervals on a peripheral wall. 3. The burner according to claim 2, wherein the large diameter portion is formed to be thick, whereby the first nozzle hole is formed in a choke shape. 4. The burner according to claim 2, wherein the axis of the first nozzle hole has an angle θ1 of 80 to 150 degrees with respect to the axis of the nozzle body. 5. The burner according to claim 2, wherein the axis of the second nozzle hole has an angle θ2 of 10 to 80 degrees with respect to the axis of the nozzle body. 6. A nozzle body, wherein a plurality of nozzle holes are formed at intervals in a circumferential direction on a peripheral wall of a cylindrical body whose downstream end of combustion air is closed. The burner according to 1. 7. The burner according to claim 6, wherein a portion of the cylinder downstream of the nozzle hole downstream of the combustion air is tapered toward the downstream of the combustion air. 8. The burner according to claim 6, wherein the axis of the nozzle hole has an angle θ1 of 80 to 150 degrees with respect to the axis of the nozzle body. 9. The burner according to claim 1, wherein the swirler is formed concentrically with an axis extending from an axis of the nozzle body. 10. The swirler has a first swirler having an axis on an extension of the axis of the nozzle body, and a swirler having an axis on an imaginary circle having a center on the extension of the axis of the nozzle body. The burner according to claim 1, further comprising a plurality of second swirlers arranged adjacent to each other in a circumferential direction. 11. The method according to claim 1, wherein the combustion air is supplied at a predetermined fixed flow rate, and a flow control valve for controlling a flow rate of fuel gas supplied to the nozzle body is provided. Burner according to one.