JPH08200623A - Burner - Google Patents

Abstract

PURPOSE: To realize high load and short flame combustion and to reduce NOX. CONSTITUTION: A spiral groove is formed in a nozzle tip 4 mounted at the end of a nozzle 30 for supplying liquid fuel, turning motion is given to fuel by the groove to spray the fuel from the tip 4 in a hollow conical liquid film state, the turning motion reverse to the turning direction of the fuel is given to the atomizing air by an air swirler 50 for atomizing, and then the air is collided with the liquid film of the fuel to so form the burner as to atomize the liquid film. An air swirler 60 for combustion is provided to give swirling motion to the combustion air, and hence the combustion of more preferable state can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner, which can be used as a burner mounted on a petroleum water heater for home use, a Stirling engine, a small combustor for a Wilmier cycle heat pump, and the like.

[0002]

BACKGROUND ART In recent years, as the performance required for the combustor using a liquid fuel such as kerosene, in addition to the low-pollution combustion to deal with environmental regulations (low NO _X, low smoke, low noise, etc.), the system The size of the combustor itself may be reduced in order to reduce the overall size and weight. And downsizing the combustor,
In addition, in order to perform highly efficient combustion, it is necessary to shorten the spray flame and increase the combustion rate per unit volume.
That is, it is necessary to carry out high load / short flame combustion.

By the way, generally, when high load / short flame combustion is performed, the combustion temperature in the furnace is increased, the generation of thermal NO _X is promoted, and the exhaust NO _X tends to increase. For this reason, it is necessary to realize flame shortening combustion, reduce the combustion volume, increase the combustion load factor, and take measures for NO _X.

[0004]

However, the conventional
For burners for oil water heaters, gun type burners, gas
A rotary rotary burner, a vaporization type burner, etc. are used.
But in any case NO _X Is 100 ppm (0% O₂Conversion
Value) around and high, low NO_X The problem of being inferior in sex
It was.

On the other hand, measures against NO _X are taken by water injection, exhaust gas recirculation, or a combination thereof to meet various regulatory values, for example, the NO _X regulatory value of 80 ppm in Tokyo (0% O ₂ conversion value). Several burners have been developed. However, there is a problem that measures against NO _X in these additional devices or post-treatments lead to enlargement of equipment and increase in equipment cost. Therefore, it has been desired to optimize the fuel spray characteristics, the combustor, and the air flow for combustion to achieve low NO _X in the combustor body.

An object of the present invention is to provide a burner capable of realizing high load, short flame combustion, and low NO _X.

[0007]

A burner according to the present invention is characterized by comprising a nozzle tip and an atomizing air swirler having the following construction. That is, the nozzle tip is attached to the tip of the nozzle for supplying liquid fuel, has a spiral groove formed by being wound around the central axis of the nozzle, and imparts a swirling motion to the fuel by this groove. The fuel is sprayed in the form of a hollow conical liquid film, and the atomizing air swirler should collide with the fuel in the form of a hollow conical liquid film on the outer peripheral side of the nozzle tip. The guide vanes are provided on the passage of the atomizing air for atomizing the fuel, and give the atomizing air a swirling motion in the direction opposite to the swirling direction of the fuel.

Further, the burner of the present invention has a guide vane which is provided on the outer peripheral side of the atomizing air swirler and on the passage for the combustion air, and which has guide vanes for giving a swirling motion to the combustion air. It is desirable to have an air swirler.

Further, in the above, the liquid film angle when the fuel is sprayed from the nozzle tip and spreads in the shape of the hollow conical liquid film is in the range of 80 to 120 degrees, and the liquid of the fuel in the hollow conical liquid film is formed. The crossing angle when the film collides with the atomizing air is preferably in the range of 60 to 110 degrees.

[0010]

According to the present invention as described above, a spiral groove is formed in the inside of the nozzle tip attached to the tip of the liquid fuel supply nozzle, and the groove gives a swirling motion to the fuel. The atomizing air swirler gives a swirling motion to the atomizing air in the direction opposite to the swirling direction of the fuel, and the atomizing air is applied to the liquid film of the fuel. The liquid film is atomized by colliding with the liquid crystal at a predetermined crossing angle.

Therefore, the liquid film and the atomizing air collide with each other while swirling in opposite directions, so that the atomizing air peels off the liquid film, and atomization is reliably performed. By setting the swirling direction of the liquid film of the fuel and the atomizing air in opposite directions, the momentum of the droplet in the swirling direction of the spray increases, and the reach distance of the spray in the downstream direction (axial direction) is increased. It is held down. Further, atomization from the liquid film to droplets and evaporation are completed early, and dispersion in the radial direction in the state of the liquid film can be reduced, and extremely short-flame combustion is realized. Also, the stronger the swirling of atomizing air, the smaller the particle size of the spray, resulting in a nonflaming flame (blue flame).
A short flame is formed. In the range where a stable flame is obtained, the flow rate of combustion air is increased to reduce the amount of nitrogen oxides and increase the combustion load factor without increasing unburned hydrocarbons. Is achieved.

Further, when a combustion air swirler is provided to give a swirling motion to the combustion air, a higher load and a shorter flame can be achieved while maintaining low NO _X.
Furthermore, the liquid film angle of the fuel that spreads in the shape of a hollow cone liquid film is set to 80
In the case of a range of up to 120 degrees and a crossing angle when the liquid film and the atomizing air collide with each other within a range of 60 to 110 degrees, it is possible to surely realize a better atomized state. become.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional view of a combustor 10 to which a burner 20 according to this embodiment is attached. Combustor 10
Is a burner 20 arranged on the left side of the drawing for atomizing and burning the fuel, a combustion chamber 11 which is a cylindrical space arranged on the right side of the burner 20, and a cylindrical wall 18 arranged on the outer peripheral side of the burner 20. A combustion air supply passage 12 that is a passage for supplying combustion air formed surrounded by
Secondary air chamber 1 that is placed on the outer periphery of
3 is provided.

The secondary air chamber 13 has a secondary air supply port 14 for supplying secondary air into the secondary air chamber 13 on the upper left side in the figure.
Is provided. Further, a cylindrical peripheral wall 15 surrounding the combustion chamber 11 is provided with a communication port 16 that communicates the combustion chamber 11 and the secondary air chamber 13 and guides the secondary air into the combustion chamber 11. Further, a combustion exhaust gas passage 17 for discharging combustion exhaust gas (a name including all of secondary air, burned fuel, and combustion air) is provided at the right end portion of the combustion chamber 11 in the figure.

The combustor 10 is adapted to supply the combustion air from the combustion air supply passage 12 and to inject the fuel from the burner 20 to burn the fuel. At the same time, in order to prevent heat loss from the peripheral wall 15 of the combustion chamber 11 due to intense heat dissipation, secondary air is circulated through the secondary air chamber 13 to recover heat, thereby increasing the overall thermal efficiency,
Further, the secondary air from which heat has been recovered is passed through the communication port 16 to the combustion chamber 1
1 is made to flow toward the center of the combustion chamber 11
The combustion gas generated inside is stirred and mixed. The size of the combustion chamber 11 is, for example, in this embodiment, a diameter H (dimension in the vertical direction in the figure) of about 200 mm and a depth L along the central axis (dimension in the horizontal direction in the figure) of about 200 mm. However, it is not limited to these numerical values.

The burner 20 includes a nozzle (spiral flow injection valve) 30 for spraying fuel into the combustion chamber 11 and the nozzle 3
And a combustion air swirler 60 provided on the combustion air supply passage 12 on the outer peripheral side of 0.

FIG. 2 shows an enlarged state of the nozzle 30. 2A shows a cross section taken along the central axis of the nozzle 30, and FIG. 2B shows the cross section taken along the line XX of FIG. The side is shown. The nozzle 30 includes an inner body 31 including the central axis of the nozzle 30, an outer body 32 arranged on the outer peripheral side of the inner body 31, and a nozzle provided on the right end of the inner body 31 in FIG. 2A. The chip 40 and the cap portion 33 fixed to the right side of the outer body 32 in FIG. 2A are provided.

At the center of the inner body 31, there is formed a fuel supply passage 34 through which the liquid fuel pressurized by a fuel pump (not shown) is circulated, and the end portion of the fuel supply passage 34 is
It is connected to the nozzle tip 40. Between the inner body 31 and the outer body 32, an atomization air supply passage 35 that is a passage of atomization air for atomizing the fuel is formed, and on the atomization air supply passage 35. An atomizing air swirler 50 that gives a swirling motion to the atomizing air is provided. The atomizing air supply passage 35 is refracted toward the center direction of the nozzle 30 at a position immediately after passing through the atomizing air swirler 50, and the downstream portion from this position is the inner body 3
It is formed by being sandwiched between 1 and the cap portion 33.

FIG. 3 shows an enlarged state of the nozzle tip 40. FIG. 3A shows a cross section taken along the central axis of the nozzle tip 40, and FIG.
The side view of (A) viewed from the right side is shown. Inside the nozzle tip 40, a cylindrical space 41 connected to the fuel supply passage 34 is provided, and within this space 41, the space 4 is formed.
A cylindrical central member 42 is provided with a gap from the inner wall surface of No. 1. The left end of the central member 42 in FIG. 3A has a conical shape and is inserted into the fuel supply passage 34 formed in the inner main body 31. Further, the right end portion of the center member 42 is fixed to the inner wall surface of the space 41 by welding or the like.

A spiral groove 43 is formed on the peripheral surface of the central member 42.
The center member 42 has a bolt-like shape. The groove 43 gives a swirling motion to the pressurized fuel sent from the fuel supply passage 34, and a hollow conical liquid film is injected from the nozzle tip 40. The details of the liquid film formation will be described later (see FIG. 5).

A portion on the right side in FIG. 3A of the space 41 is formed with a trumpet portion 45 that narrows in a conical shape toward the center and expands in a trumpet shape with the throat portion 44 as a boundary. The spread angle E of the trumpet portion 45 is, for example, 100 degrees, the diameter K of the throat portion 44 is, for example, 0.5 mm, and the diameter M of the trumpet portion 45 at the most distal end portion 46 of the nozzle tip 40.
Is, for example, 1 mm, but is not particularly limited to these numerical values. Further, the size of the nozzle tip 40 is, for example, in the present embodiment, the outer diameter P of which is about 5 mm, but is not limited to this numerical value.

Although the groove 43 is formed in a spiral shape like a male screw, the number of grooves (corresponding to the number of threads of the screw) is one in this embodiment, but it is two as in the case of a multiple thread. More than one groove may be formed. The width F of the groove 43 is preferably 1 to 5 mm. The depth G of the groove 43 is preferably 1 to 5 mm. If the depth G is less than 1 mm, the flow rate coefficient at the nozzle tip 40 becomes small and a predetermined flow rate cannot be obtained, while if it exceeds 5 mm, the swirling speed of the fuel becomes small and the flow rate will be described later. This is because the formation of the liquid film at the tip of the nozzle 30 and the atomization of the droplets become insufficient. Further, the peripheral surface of the portion of the center member 42 where the groove 43 is not formed (the portion corresponding to the position of the crest of the male screw)
The clearance dimension Y between the inner wall surface of the space 41 and the inner wall surface of the space 41 is, for example, 5
Although it is about mm, it is not limited to this value.

The cross-sectional shape of the groove 43 is not particularly limited,
A rectangular shape or a trapezoidal shape is preferable in terms of processing. Angle Q of groove 43 (angle with respect to the direction perpendicular to the central axis of the nozzle 30)
Is, for example, 15 degrees, and is preferably in the range of 10 to 20 degrees. In this range, the liquid film angle ζ of the spray at the tip of the nozzle 30 (see FIG. 5 described later) is 80 to 120 degrees, The atomization of the droplets by the atomizing air can be made in a good state. If this angle Q is less than 10 degrees, the liquid film angle ζ becomes too large and the spray reaches a large distance in the radial direction, so that the fuel droplets evaporate and the combustion chamber 11 is completed before the combustion is completed. It collides with the peripheral wall 15 and causes unburned hydrocarbons (THC) to increase. On the other hand, the angle Q is 2
When the angle is larger than 0 degree, the liquid film angle ζ becomes small and the spray reaches a long distance in the axial direction, so that the spray flame becomes long and it becomes difficult to shorten the flame.

Returning to FIG. 2, the throttle portion 36 through which the fuel injected from the nozzle tip 40 passes is formed at the center of the cap portion 33, that is, at the extended position of the line from the fuel supply passage 34 to the nozzle tip 40. ing. The mixing distance δ, which is the distance between the narrowed portion 36 and the most distal end portion 46 of the nozzle tip 40, is preferably in the range of 1 to 5 mm. Is 80
When it goes out of the range of 120 degrees, the atomized state is significantly deteriorated, which causes soot generation.

In other words, by changing the mixing distance δ, the position where the liquid film sprayed from the tip portion 46 of the nozzle tip 40 collides with the atomizing air is subtly changed,
It greatly affects the atomization state inside the nozzle 30. Even when the angle Q of the groove 43 in the nozzle tip 40 and the swirling angle θ of the atomizing air swirler 50 (see FIG. 4, which will be described later) are the same, the liquid film is changed by changing the mixing distance δ. There is a change in the angle ζ. In particular,
When it deviates from the above-mentioned preferable range of 1 to 5 mm, the phenomenon that the liquid film angle ζ greatly changes and the atomization state deteriorates is observed. This is the mixing distance δ
Is less than 1 mm, the collision and mixing of the liquid film formed by the nozzle tip 40 with the atomizing air is insufficient, while if the mixing distance δ is greater than 5 mm, the atomized droplets are separated from each other. It is considered that the main cause is that the collision occurs again inside the nozzle 30 and the droplet diameter becomes coarse and the atomized state deteriorates.

The outlet diameter A of the nozzle 30, which is the diameter of the narrowed portion 36, is preferably in the range of 2 to 5 mm. When the outlet diameter A is smaller than 2 mm, the liquid film of the spray swirled by the nozzle tip 40 collides with the cap portion 33 and causes liquid dripping, which deteriorates the atomized state. On the other hand, when the outlet diameter A is larger than 5 mm, the liquid film angle ζ is 120
The spray width becomes too large and the spray collides with the peripheral wall 15 of the combustion chamber 11 in a liquid state.

FIG. 4 shows an enlarged state of the atomizing air swirler 50. The atomizing air swirler 50 is
The ring-shaped member is provided with a plurality of guide blades 51 on its outer periphery for giving a swirling motion to the atomizing air. Then, the atomizing air given the swirling motion by the atomizing air swirler 50 is the nozzle tip 4
A shear force is applied to the liquid film of fuel injected from 0 to atomize the liquid film. Further, the swirling direction of the atomizing air by the atomizing air swirler 50 is opposite to the swirling direction of the liquid film of fuel by the groove 43 in the nozzle tip 40.

Guide vanes 51 of air swirler 50 for atomization
The angle θ (formation angle of the guide blade 51 with respect to the central axis of the nozzle 30) is preferably in the range of −30 to −60 degrees. Note that the minus sign attached to the angle θ means that the atomizing air is swirled in the direction opposite to the swirling direction of the liquid film. The preferable range of the angle θ of the guide blade 51 of −30 to −60 degrees is based on the following reason. That is, in order to obtain a good atomization state of the spray, the angle formed by the advancing direction of the fuel liquid film and the advancing direction of the atomizing air, that is, the intersection angle at the time of collision between the liquid fuel and the atomizing air. ω (see FIG. 5 described later) is 60 to
A range of 110 degrees is suitable. On the other hand, the liquid film angle ζ is 80
This is because the range of ˜120 degrees is desirable, so that if the angle θ of the guide vanes 51 is set in the range of −30 to −60 degrees, the intersection angle ω can be adjusted within the appropriate range of 60 to 110 degrees. The angle θ of the guide vanes 51 is −30 to −60.
When it is out of the range of the degree, the shearing force applied to the liquid film of the spray becomes small, and a sufficient atomized state cannot be obtained.

Further, the shape, size, length, number, etc. of the guide vanes 51 are arbitrary as long as they can give a predetermined swirling motion to the atomizing air. For example, in the present embodiment, ten guide blades 51 having a substantially rectangular cross section and having an axial length T of about 8 mm and a height S of about 2 mm are provided, but the number is not limited to these values. Not something.

The combustion air swirler 60 shown in FIG.
Is a ring-shaped member having the same shape as the atomization air swirler 50, and a plurality of guide blades 61 (not shown) for giving a swirling motion to the combustion air are provided on the outer periphery thereof. Further, the swirling direction of the combustion air by the combustion air swirler 60 is the same as the swirling direction of the liquid film of the fuel by the groove 43 in the nozzle tip 40, that is, the swirling direction of the atomizing air by the atomizing air swirler 50. Is the opposite direction.

The angle β of the guide vanes 61 of the combustion air swirler 60 (not shown, but the atomization air swirler 50).
Is the angle corresponding to the angle θ of the guide blade 51, and the formation angle of the guide blade 61 with respect to the central axis of the nozzle 30 is 4
The range of 0 to 70 degrees is desirable. The angle β of the guide vanes 61 is 4 in order to achieve low NO _x and stable combustion.
The range of 0 to 70 degrees is sufficient, but 55 to 60 is required for higher load and short flame combustion while maintaining low NO _X.
It is more desirable to set the range of degrees. Also, the guide blade 6
The shape, size, length, number, etc. of 1 are arbitrary as long as a predetermined swirling motion can be given to the combustion air.

In this embodiment, the liquid fuel is burned as follows. FIG. 5 is a schematic diagram in the vicinity of the tip of the nozzle 30 showing the situation from the fuel supply to the formation of the air-fuel mixture of fuel and combustion air. The liquid fuel pressurized by the fuel pump is guided into the nozzle tip 40 through the fuel supply passage 34, and is given a swirling motion by the spiral groove 43 formed in the nozzle tip 40 to form a hollow conical liquid film. As a nozzle tip 40
It is injected from the most advanced part 46 of. Liquid film angle ζ at this time
The angle of the apex of the cone is preferably 80 to 120 degrees.

Further, atomizing air is supplied through the atomizing air supply passage 35, and the atomizing air is given a swirling motion in the direction opposite to the fuel by the atomizing air swirler 50 to cause the liquid of the fuel to flow. Collisions crossing the membrane. That is, the liquid film and the atomizing air collide while swirling in opposite directions. The crossing angle ω (the angle between the traveling direction of the liquid film and the traveling direction of the atomizing air) at the time of this collision is 60 to
110 degrees is desirable.

Further, the liquid film which has received the collision of the atomizing air is atomized and then mixed with the combustion air swirled by the combustion air swirler 60, whereby the air-fuel mixture for combustion is mixed. Is formed.

Here, regarding the fuel flow rate MF and the combustion air flow rate MC, for example, MF = 0.5 to 1.5 g /
s, if the condition that MC = 10~35g / s, the low NO _X combustion is achieved in a very short flame. And the fuel flow rate M
When F is less than 0.5 g / s, the atomized state deteriorates, and stable combustion cannot be obtained. However, even when the fuel flow rate MF is larger than 1.5 g / s, the equivalence ratio (the amount of air actually used for combustion / the theoretically required amount of air) is φ = 0.5 to 1.0. By adjusting the fuel flow rate MF and the combustion air flow rate MC to fall within the range, it is possible to perform high load / short flame combustion with low NO _X. Also,
As the fuel, for example, kerosene, A heavy oil, etc. can be preferably used under the above conditions, and by changing the conditions, any fuel can be used as long as it is a liquid fuel such as a relatively viscous fuel. The present invention can also be applied.

According to this embodiment, the following effects can be obtained. That is, since the spiral groove 43 is provided inside the nozzle tip 40, the fuel can be swirled and the fuel can be sprayed in the shape of a hollow conical liquid film. Further, since the atomizing air swirler 50 is provided, the atomizing air can be given a swirling motion.
Since the spiral groove 43 and the guide vanes 51 of the atomizing air swirler 50 are formed so as to swirl the fuel and the atomizing air in opposite directions, the liquid film of the fuel and the fine particles are formed. The atomizing air can be made to collide with each other while swirling in opposite directions, and at this time, the atomizing air is in a state of stripping off the liquid film, so that atomization can be reliably performed.

By setting the swirling directions of the liquid film of the fuel and the atomizing air in opposite directions, the momentum of the liquid droplets in the swirling direction of the spray increases, and the spray moves in the downstream direction (axial direction). You can suppress the reach. Further, atomization from the liquid film into droplets and evaporation are completed at an early stage, and dispersion in the radial direction in the state of the liquid film can be reduced, so that extremely short flame combustion can be realized. Furthermore, the realization of short-flame combustion makes it possible to reduce the size of the combustor 10.

Further, if the swirling of the atomizing air is strengthened, the particle size of the spray can be made small, and a short flame in a dull flame state (blue flame) can be formed. Then, in a range where a stable flame is obtained, it is possible to reduce the nitrogen oxides and increase the combustion load factor by increasing the flow rate of the combustion air without increasing the unburned hydrocarbons. Further, by realizing high-load combustion, it is possible to improve the efficiency of the combustor 10, and by realizing low NO _X , it is possible to easily cope with environmental regulations.

Further, since the combustion air swirler 60 is provided, it is possible to give a swirling motion to the combustion air, and it is possible to further increase the load and shorten the flame while maintaining low NO _X. it can.

Further, if the liquid film angle ζ is set in the range of 80 to 120 degrees and the crossing angle ω at the time of collision of the liquid film and the atomizing air is set in the range of 60 to 110 degrees, it is more preferable. The atomized state can be surely realized. The setting of such a range is performed by setting the angle Q of the groove 43 in the nozzle tip 40,
The mixing distance δ of the nozzle 30, the outlet diameter A of the nozzle 30, or the angle θ of the guide blade 51 of the atomizing air swirler 50.
It can be easily performed by adjusting.

Further, if the angle β of the guide vanes 61 of the combustion air swirler 60 is adjusted within the range of 40 to 70 degrees, then it will be lowered.
NO _X and stable combustion can be realized more reliably, and further 55-
By adjusting the range to 60 degrees, it is possible to achieve higher load and shorter flame combustion while maintaining low NO _X.

An experiment for carrying out the present invention was conducted to examine the exhaust characteristic. In FIG. 6, the fuel flow rate MF = 0.85 g /
Combustion load factor converted from the NO _x emission concentration and methane equivalent THC (unburned hydrocarbon) emission concentration at the combustor outlet and the exhaust temperature when the combustion air flow rate MC is changed with s being constant. The change in IC is shown. According to this result, when the combustion air flow rate MC is increased, the THC emission concentration rapidly increases in the range of MC = 30 g / s or more. On the other hand, the NO _X emission concentration once increases, reaches a maximum value, and then decreases. The range of the combustion air flow rate MC surrounded by the diagonal lines in the figure is a range in which a stable blue flame is obtained, and within this range, the THC emission amount is increased by increasing the combustion air flow rate MC. It can be seen that the NO _x emission amount can be reduced and the combustion load factor IC can be improved with almost no increase. The combustion load factor IC of the conventional burner is 3.0.
MW / m ³ or less. From the above, according to the present invention,
It was remarkably shown that excellent exhaust characteristics were obtained.

The present invention is not limited to the above-mentioned embodiments, and modifications and the like within the range in which the object of the present invention can be achieved are included in the present invention. That is, the burner 20 of the present invention is not limited to being mounted on the combustor 10 having a structure as shown in FIG. 1, and many other devices such as a petroleum water heater for home use, a Stirling engine, and a vilmier. It can be widely applied to small combustors for cycle heat pumps.

Further, in the above-mentioned embodiment, the burner 20 has a structure provided with the combustion air swirler 60, but the burner of the present invention does not necessarily have to have such a combustion air swirler 60. In short, in short, it is sufficient that the combustion air can be supplied to the liquid film of the atomized fuel.

Further, in the above embodiment, the nozzle tip 4
In the inside of 0, a spiral groove 43 was formed in the central member 42, and the fuel was given a swirling motion by the groove 43 formed in the male screw shape (corresponding to the valley of the male screw). The groove in the nozzle tip of the invention is not limited to such a configuration, and for example, an internal thread-shaped groove (corresponding to a valley of an internal thread) may be formed on the inner wall surface of the space 41, or an external thread. Both the groove 43 and the female screw groove may be formed. However, in order to give the swirling motion to the fuel effectively,
The male screw-shaped groove 43 as in the above embodiment is preferable.

[0046]

As described above, according to the present invention, the spiral groove formed inside the nozzle tip imparts a swirling motion to the fuel to spray the fuel from the nozzle tip in the form of a hollow conical liquid film. At the same time, the atomizing air swirler imparts a swirling motion to the atomizing air in a direction opposite to the swirling direction of the fuel, and the atomizing air collides with the liquid film of the fuel at a predetermined intersecting angle. In addition to achieving load and flame reduction combustion, there is an effect that low NO _X can be achieved.

Further, when a combustion air swirler is provided to give a swirling motion to the combustion air, it is possible to achieve a higher load and a shorter flame while maintaining low NO _X. effective. Further, the liquid film angle of the fuel that spreads in the shape of a hollow cone liquid film is set in the range of 80 to 120 degrees, and the crossing angle when the liquid film and the atomizing air collide is 60 to 60 degrees.
When the range is 110 degrees, there is an effect that a more excellent atomization state can be surely realized.

[Brief description of drawings]

FIG. 1 is a sectional view of a combustor showing an embodiment of the present invention.

FIG. 2 is an enlarged view of the nozzle of the embodiment.

FIG. 3 is an enlarged view of the nozzle tip of the above embodiment.

FIG. 4 is an enlarged view of the air swirler for atomization of the above embodiment.

FIG. 5 is a schematic diagram in the vicinity of the tip of the nozzle showing the situation from the fuel supply to the formation of the air-fuel mixture of fuel and combustion air in the embodiment.

FIG. 6 is an explanatory diagram showing an exhaust characteristic when the present invention is implemented.

[Explanation of symbols]

 10 Combustor 12 Combustion air supply path 20 Burner 30 Nozzle 35 Atomization air supply path 40 Nozzle tip 43 Groove 50 Atomization air swirler 60 Combustion air swirler ζ Liquid film angle ω Crossing angle

Claims (3)

[Claims] 1. A spiral groove, which is attached to a tip of a nozzle for supplying liquid fuel and is formed by being wound around a central axis of the nozzle, has a swirling motion of the fuel by the groove. A nozzle tip for giving the fuel to spray the fuel in the shape of a hollow conical liquid film, and the fuel by colliding with the fuel in the shape of the hollow conical liquid film on the outer peripheral side of the nozzle tip. An atomizing air swirler having guide vanes provided on a passage for atomizing air for atomizing the atomizing air, and providing the atomizing air with a swirling motion in a direction opposite to the swirling direction of the fuel. Characteristic burner. 2. The burner according to claim 1, further comprising guide vanes provided on the outer peripheral side of the atomizing air swirler and on the passage for the combustion air, for giving a swirling motion to the combustion air. A burner characterized by being provided with an air swirler for combustion. 3. The burner according to claim 1 or 2, wherein a liquid film angle when the fuel is sprayed from the nozzle tip and spreads in a hollow conical liquid film shape is 80 to 12.
The crossing angle when the liquid film of the fuel, which is in the form of a hollow conical liquid film, and the air for atomization is in a range of 0 degree, is:
A burner characterized by being in the range of 60 to 110 degrees.