JP2003047892A - Wall surface collision type liquid atomizing nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To atomize and jet a spouted liquid from a nozzle with the application of misty atomization of a liquid, which is performed by spouting the pressurized liquid from fine bole at a high speed and bringing the columnar jet stream to collide with a solid collision wall surface. SOLUTION: The wall surface collision type liquid atomizing nozzle 10 has a cylindrical injector 12 in which a passage for a liquid (fuel) 11 is formed and a cylindrical body 16 assembled coaxially in the outside thereof and provided with the collision wall surface 15 forming a part of a continuous conical surface in the circumferential direction at an end part. The liquid jet stream 14 jetted in the diameter direction from a plurality of jetting holes 13 formed in the injector 12 collides with the collision wall surface 15 of the cylindrical body 15 to form a liquid film extending obliquely outward to be atomized. The wall surface collision type liquid atomizing nozzle 10 highly atomizes the fuel even at a low jetting pressure and can be applied to a gas turbine combustor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel nozzle for atomizing and injecting liquid fuels used in gas turbines, boilers and the like, liquids such as agricultural chemicals and disinfectants.

[0002]

2. Description of the Related Art Conventionally, as a fuel injection nozzle applied to a combustor of a gas turbine, as shown in FIG. 6, a fuel injection hole formed at the tip of a fuel injection nozzle 50 by a structure such as a spiral groove 53. Nozzles of the type that impart swirl to the flow of fuel in the space 52 immediately upstream of 51, that is, swirl nozzles, have been widely used. In the case of a fuel injection nozzle having a simple structure that does not give a swirl to the fuel flow, such as a fuel nozzle of a simple diesel engine, it is necessary to apply an injection pressure exceeding 100 MPa to the injected fuel. However, in the swirl nozzle, the fuel is ejected as a thin liquid film that is easily split due to its swirling action, so that with a small capacity, the fuel can be atomized well even at a relatively low injection pressure of about 0.5 MPa. .

Swirl nozzles with good atomization are used not only as fuel injection nozzles for various engines, but also as pesticide sprayer nozzles and small boiler fuel nozzles.
Recently, the swirl nozzle is also used as a fuel injection nozzle for a gasoline engine of a cylinder injection type for automobiles, but the fuel injection pressure in this case exceeds 5 MPa. The fuel spray injected from the swirl nozzle generally has a good mixture of fuel and air because the fuel particles are small and develop into a conical shape due to their swirling action. Therefore, the penetration distance of the spray is shorter than that of the spray of the fuel nozzle of the diesel engine.

By the way, in a recent high pressure ratio gas turbine, an air flow atomization (air blast) fuel nozzle 60 for atomizing fuel by an air flow flowing into a combustor as shown in FIG. 7 is used. Tend to The fuel is supplied onto the inner wall surface of an annular thin cylinder called a filmer (liquid film forming device) 61, and the fuel liquid film formed on the cylindrical wall surface is separated from the tip 62 of the filmer 61 by the shearing action of the air flow in contact therewith. Atomized. In many cases,
The airflow F is made to flow along both inner and outer surfaces of the filmer, and the airflows Fi and Fo are swirled by swirl vanes 63 and 64. Airflow speed is usually 100m
/ S.

As a background of the use of the air stream atomization method in a gas turbine with a high pressure ratio, it is becoming difficult to suppress smoke and NOx by mixing fuel and air in a swirl nozzle as the combustion pressure rises. Since the maximum / minimum fuel flow rate ratio has widened and it has become necessary to lower the injection pressure on the small flow rate side, it has become difficult to achieve fine atomization, and it is necessary to increase the turbine cooling air amount. A larger pressure loss than before was allowed in the liner, and the speed of the air flow flowing into the liner was increased. Therefore, even with the air flow atomization method, atomization at the same level as or higher than that of the swirl nozzle was possible.

With respect to NOx, further emission reduction is required not only from the viewpoint of preventing air pollution but also from the viewpoint of preventing global warming and protecting the ozone layer. In gas turbines that use liquid fuel, NOx
Although it has been clarified in the basic test that it is effective in suppressing fuel consumption, when the air temperature rises, the time delay between the injection of fuel into the air and the ignition is shortened rapidly, so the fuel evaporates completely. There is an essential problem that it ignites before starting. This problem becomes more remarkable as the pressure becomes higher. Therefore, the pre-evaporation and pre-mixing of the fuel has not yet been put to practical use. If the fuel particles are small enough, the evaporation time will be shorter and the evaporation can be completed before ignition, so a fuel nozzle that can generate much finer spray than conventional fuel nozzles can be used to solve this problem. It is essential.

It can be said that the atomizing performance of the air stream atomizing fuel nozzle is determined substantially by the air stream velocity if the formation of the liquid film is appropriate. That is, the effect of improving the atomization by improving the design of details cannot be expected so much.
As a result of spray measurement of airflow atomizing fuel nozzles of various designs up to now, the representative diameter (for example, the average body surface area diameter) of the spray particles may change in inverse proportion to the power of 1 to 1.2 to the airflow velocity. I know it. The airflow velocity is proportional to the square root of the pressure difference (differential pressure) of the combustor liner to which the airflow atomizing fuel nozzle is attached, so if the representative particle size is halved, the pressure difference will be approximately four times. There is a need. Most of this differential pressure is loss of differential pressure energy (pressure loss), and an increase in differential pressure is directly linked to an increase in fuel consumption. Therefore, increasing differential pressure only for the purpose of improving atomization performance is out of the question. Is.

[0008]

It is known that liquid can be atomized into a mist by ejecting a pressurized liquid at high speed from a fine hole and colliding the columnar jet with a solid wall surface. The liquid column that collides with the wall surface spreads in a film shape on the wall surface, and it jumps out from the edge of the wall surface into the free space and splits. Therefore, there is a problem to be solved in that atomization by wall collision is used to atomize and eject the ejected liquid from the ejection nozzle.

An object of the present invention is to provide a nozzle capable of atomizing and ejecting a liquid by utilizing atomization due to wall collision, and particularly when used in a gas turbine, the pressure of the combustor is also provided. Without increasing loss
It is an object of the present invention to provide a wall impingement type liquid atomization nozzle that enables atomization of liquid fuel into fine particles, which is impossible with conventional fuel nozzles for gas turbines.

[0010]

In order to solve the above problems, the wall collision type liquid atomizing nozzle of the present invention is
A cylindrical injector having an injection hole for ejecting a pressurized liquid, and a collision wall surface disposed outside the injector substantially coaxially with the injector and colliding with a liquid jet injected from the injection hole. And a cylindrical body. According to this wall collision type liquid atomization nozzle, the liquid jet flow of the pressurized liquid ejected from the ejection hole of the ejector is applied to the cylindrical body disposed outside the ejector and substantially coaxial with the ejector. It collides with a collision wall surface to form a coaxial liquid film around the injector and scatters from the liquid film to atomize the injector into mist.

In the above wall collision type liquid atomizing nozzle, the injection hole of the injector is formed so as to penetrate in the radial direction, and the collision wall surface of the cylindrical body is formed at the tip end portion of the cylindrical body. A continuous jet surface in the circumferential direction, or by making a notch in the circumferential direction at the tip of the cylindrical body or by forming an independent columnar projection at the tip of the cylindrical body, the liquid jet flow from each of the ejection holes. Can be individual discontinuities. When the wall impingement type liquid atomization nozzle is configured as such a radial jet type, the radial liquid jets jetted from the plurality of jet holes formed in the wall surface of the cylindrical injector are In the case where a circumferential continuous surface is formed at the tip of the cylindrical body that is disposed substantially coaxially with the injector,
It collides with the continuous surface and makes a notch in the circumferential direction at the tip of the cylindrical body or is formed into a columnar protrusion independently processed at the tip of the cylindrical body to form a discontinuous surface. In that case, the discontinuities are individually impacted.

Further, in the above wall collision type liquid atomizing nozzle, the line of intersection of the collision wall formed on the cylinder with a plane orthogonal to the axis of the cylinder is a quadratic curve or a part thereof. It can be the wall represented. In the case of a continuous surface as one of such collision wall surfaces, it can be a conical inner wall surface that spreads outward in the nozzle tip direction, and at this time, the line of intersection with the plane orthogonal to the axis of the cylindrical body. Becomes a circle. Further, when the collision wall surface is formed on the columnar protrusion, it can be a wall surface formed of a part of a cylindrical surface or a parabolic surface. At this time, the line of intersection with the plane orthogonal to the axis of the cylinder is a circle. And become a part of a quadratic curve such as a parabola. If the line of intersection of the collision wall surface with the plane orthogonal to the axis of the cylinder is a quadratic curve, and the line of intersection with the plane containing the axis of the cylinder is linear, the collision wall surface becomes a so-called quadric surface, which is a three-dimensional curved surface. It is much easier to manufacture compared to. In the case of continuous collision wall surfaces, if the wall surface is a curved surface such as a cone whose intersection with a plane orthogonal to the axis of the cylindrical body is a circle, the collision wall surface is a rotationally axisymmetric curved surface, so the cylindrical body is rotated. Machining can be easily performed only by moving the cutting tool along the generatrix of the rotating body, and a highly accurate product can be manufactured at low cost. Further, when the liquid jet flow jetted in the radial direction is made to collide with the collision wall surface thus formed, it is possible to form an axisymmetric spray after the collision.

In a wall collision type liquid atomization nozzle having a collision inner wall surface as a conical inner wall surface, an outer peripheral surface of the cylindrical body is connected to the inner conical wall surface by an edge, and the edge side is formed along the outer peripheral surface of the cylindrical body. It is preferable to flow an air flow toward. When the liquid film flows out of the collision surface into the space, the liquid sometimes goes around to the other surface connected to the collision surface, for example, the outer peripheral surface of the cylindrical body, but goes to the edge side along the outer peripheral surface of the cylindrical body. The wraparound of the liquid is avoided by flowing the airflow and generating the airflow flowing to the tip of the collision surface. By giving a swirl to the flow in the circumferential direction of the cylindrical body, it is possible to further avoid the wraparound of the liquid and further atomize the colliding liquid jet. Further, by forming a coating layer made of a hydrophobic material on the surface of at least the portion in the vicinity of the edge which is a part of the outer peripheral surface of the cylindrical body, the wraparound of the liquid film is further avoided.

Further, in the above wall impingement type liquid atomizing nozzle, the injection hole of the injector is formed so as to penetrate through in the axial direction, and the collision wall surface is formed with a through hole formed at the tip of the cylindrical body. The wall surface of the hole can also be used. That is, the liquid jet injected from the injection hole formed in the tip end wall of the cylindrical injector collides with the hole wall surface of the through hole formed by obliquely penetrating the closed end wall surface of the cylindrical body. A liquid film is formed by. In the above structure, since there is no object supporting the collision wall surface in front of the spray, it can be used as a fuel nozzle of a combustor. With this wall collision type liquid atomization nozzle,
It is possible to arrange a large number of liquid jets, and then, like the swirl nozzle, it is possible to generate a conical spray that is a shape suitable for combustion.

In the wall collision type liquid atomizing nozzle in which the collision wall surface is the hole wall surface of the through hole formed in the tip end portion of the cylindrical body, the tip end portion of the cylinder body is close to the through hole or by an edge. It is preferable to form an airflow passage that opens in a connected state. When the liquid film flows out of the collision surface into the space, sometimes the other surface where the liquid connects to the collision surface,
For example, although it may wrap around the tip end surface of the cylindrical body, the wraparound of the liquid is avoided by the air flow blown out from the air flow passage by providing the air flow passage that opens in the state of being close to or connected to the through hole by the edge. By giving a swirl around the axis of the cylindrical body to this flow, it is possible to further prevent the liquid from wrapping around and further atomize the colliding liquid jet.
Further, when a coating layer made of a hydrophobic material is formed on the tip end surface of the cylindrical body or the surface of the airflow passage near the hole wall surface of the through hole, the wraparound of the liquid film is further avoided.

Further, in the above wall impingement type liquid atomizing nozzle, an angle between a normal direction of the impinging wall surface and a jetting direction of the liquid jet on the impinging wall surface on which the liquid jet collides is 110 degrees to 160 degrees. Can be placed in a range of degrees. By setting the intersecting angle between the collision wall surface and the liquid jet in this angle range, the liquid film can be effectively spread in the jet direction to form a thin film, and the atomization of the liquid can be promoted.

Further, in the above wall impingement type liquid atomizing nozzle, a communication hole through which an air stream flows toward the inside of the cylinder can be formed in the cylinder wall of the cylinder. By forming the communication hole in the cylindrical wall of the cylindrical body, it is possible to prevent the spray from entering the space inside the nozzle by the airflow flowing into the cylinder from the communication hole. When the atomized liquid from the fuel nozzle is the fuel, the inflow air (air) from the communication hole removes the radiant heat from the flame generated when the fuel is burned in the combustor, and the high temperature combustion gas is the fuel. It is also effective in preventing staying in the vicinity of the nozzle.

In the wall impingement type liquid atomization nozzle which allows the inflowing air to enter from the communication hole, the central axis of the communication hole can be placed in a twisted position relationship with the axis of the injector. By arranging the central axis of the communication hole at a position twisted with the axis of the injector, swirl is given to the air flow (air) flowing in through the communication hole, and a flow along the inner wall of the cylinder is formed. It can be pushed out more effectively.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a wall collision type liquid nozzle according to the present invention will be described below with reference to the drawings. FIG. 1 is a view showing a wall impingement type liquid atomization nozzle which is an embodiment of the present invention, and FIG.
(B) is an end view showing a fuel injection state. A wall collision type liquid atomization nozzle (hereinafter abbreviated as “atomization nozzle”) 10 shown in FIG. 1 is applied to a gas turbine combustor using liquid as a fuel, and has a tip closed and a fuel 11 inside. Cylindrical injector 12 having a passage formed therein
And a cylindrical body 16 coaxially assembled on the outside of the injector 12 and having an end portion with a collision wall surface 15 continuous in the circumferential direction. A plurality of (six in this embodiment) injection holes 13 extending in the radial direction are formed in the peripheral wall of the tip of the injector 12. The injection holes 13 are preferably formed at equal intervals in the circumferential direction of the tip of the injector 12. The collision wall surface 15 formed at the end of the cylindrical body 16 is a surface of a rotating body that is continuous in the circumferential direction coaxial with the axis of the cylinder, or a part thereof.
The line of intersection with the plane orthogonal to the axis of is a circle. The collision wall surface 15 is preferably a part of a circumferentially continuous conical surface formed coaxially with the axis of the cylindrical body 16. By forming the continuous collision wall surface 15 into a conical surface having a straight generatrix or a curved surface that is rotationally symmetric with respect to a parabola of the generatrix, the rotating cylindrical body is processed by applying a cutting tool to the collision wall surface 15. Machining becomes easy, and a highly accurate cylindrical product can be manufactured at low cost.

The liquid jet flow 14 of the fuel injected radially from the injection hole 13 collides with the collision wall surface 15 of the cylindrical body 16.
The fuel that has collided with the collision wall surface 15 forms a liquid film that spreads obliquely outward because the collision wall surface 15 is a conical surface, and then atomizes. Since the collision wall surface 15 is a part of the conical surface which is coaxial, the spray generated after the collision collides with the atomization nozzle 10.
Is formed to be axisymmetric with respect to. Fuel spray is on collision wall 1
5, the spray having a desired divergence angle can be easily generated by changing the cone angle of the collision wall surface 15. As shown in FIG. 1A, the direction at the collision point A of the collision wall surface 15 (direction n of the normal to the surface).
Defined by 1.) and the direction i of the liquid jet flow is set in the range of 110 to 160 degrees. By setting the angle θ within this angle range, the extension of the liquid film is effective after the collision of the liquid jet flow 14, the liquid film is thinned, and thereafter atomization is further promoted.

On the upstream side of the cylindrical wall of the cylindrical body 16, there is provided a communication hole 19 for allowing air to flow into an annular space formed between the injector 12 and the cylindrical body 16. . The air flow Fa1 flowing in through the communication hole 19 prevents the fuel spray atomized by the collision on the collision wall surface 15 from entering the annular space, and when the atomizing nozzle 10 is used in the combustor, the flame is burned. The temperature rise of the wall surface due to the radiant heat from the wall is prevented, and the high temperature combustion gas is prevented from staying in the vicinity of the atomizing nozzle 10. By arranging the central axis of the communication hole 19 in the relationship of the axis of the injector 12 and the position of the twist, the air flow Fa1 flowing through the communication hole 19 can be swirled. By giving swirl to the air flow, an air swirling flow is formed along the inner wall of the cylinder body 16, so that the spray can be more effectively pushed forward from the collision wall surface 15 formed at the tip of the cylinder body 16. You can

In this embodiment, a concentric cylinder 17 is provided outside the cylindrical body 16, and the outer peripheral surface 16a of the cylindrical body 16 and the collision wall surface 15 which is the inner wall surface of the cone are edges 15.
It is connected by a. In the annular passage formed between the outer cylindrical surface 16 a of the cylindrical body 16 and the cylinder 17, the cylindrical body 16
An air flow Fa2 such as air flows along the outer peripheral surface 16a toward the edge side 15a. When the liquid film flows out of the collision wall surface 15 into the space, the liquid sometimes goes around the outer peripheral surface 16a of the cylindrical body 16 connected to the collision wall surface 15. By flowing the air flow Fa2 toward the edge 15a at the tip of the liquid, the wraparound of the liquid is avoided. It is possible to further atomize the impinging liquid jet by giving a swirl to the air flow Fa2 in the circumferential direction of the cylindrical body 16 by an appropriate guide means or the like. By forming the coating layer 16b made of a hydrophobic material on the surface of at least the edge 15a which is a part of the outer peripheral surface 16a of the cylindrical body 16, it is possible to further prevent the liquid film from wrapping around.

2A and 2B are views showing a wall impingement type liquid atomizing nozzle which is another embodiment of the present invention. FIG. 2A is a longitudinal section thereof, and FIG. 2B is an end view showing a liquid jetting state. is there. The wall collision type liquid atomization nozzle shown in FIG. 2 (hereinafter,
The "atomization nozzle" 20 has a similar structure except that the structure of the cylindrical body 16 is different. Therefore, in principle, the same reference numerals are given to the constituent elements and parts having the same function. The detailed description of is omitted. Atomizing nozzle 2
In the end portion 21 of the cylindrical body 16, 0 is a plurality of triangular cross-sections that project in the axial direction at positions spaced at equal intervals in the circumferential direction (6 like the injection holes 13), corresponding to the respective injection holes 13. ) Columnar protrusions 22 are provided. Since each columnar protrusion 22 is arranged concentrically and independently of the injector 12,
A gap 23 is formed between the adjacent columnar protrusions 22, 22. The side surface of the columnar protrusion 22 forms a collision wall surface 25 that is inclined or curved with respect to the liquid jet flow 24 ejected from each ejection hole 13. Collision wall surface 25 and cylindrical body 16
The line of intersection with the plane orthogonal to the axis of can be part of a circle (or a quadratic curve close to it).

Liquid jet 24 jetted from each jet hole 13
Collides with the collision wall surface 25 formed on the columnar protrusion 22, and a liquid film spreading outward through the gap 23 is generated.
The liquid film becomes a spray having a spread in the axial direction as shown in FIG. 2A by the collision on the collision wall surface 25. The spray grows in the same plane as the collision wall surface 25. Therefore, by changing the inclination angle or the positional relationship between the collision wall surface 25 and the axis of the atomizing nozzle 20, it is possible to form a spray having a shape with a considerable degree of freedom. A nozzle can be realized. Further, regarding the hole shape of the injection hole 13 formed in the injector 12, as shown in FIGS. 2C and 2D, the elongated hole 26 is formed in the circumferential direction.
It can be formed in the round hole 27 or the round hole 27.

FIG. 3 is a view showing a wall collision type liquid atomizing nozzle which is still another embodiment of the present invention, (a).
Is a longitudinal section thereof, and (b) is an end view showing a fuel injection state. The wall collision type liquid atomizing nozzle shown in FIG.
A plurality of "atomization nozzles" 30 are provided (6 in the example shown in the figure) to eject the fuel 11 toward the tip wall 31 in the axial direction.
(3) Cylindrical injector 32 having injection holes 33 formed therein
And a cylindrical body 36 coaxially fitted to the outside of the injector 32. The end wall surface 37 of the cylindrical body 36 is radially formed with a plurality of (six like the injection holes 33) through-holes 38 having a circular cross-section, corresponding to the injection holes 33. The axis of the through hole 38 is the liquid jet 34 ejected from each ejection hole 33.
Inclined with respect to the direction of the
The hole wall surface of No. 8 is a collision wall surface 35 that collides with the liquid jet 34.

Liquid jet 34 jetted from each jet hole 33
Collides with the surface portion of the collision wall surface 35 located on the radially inner side of the cylindrical body 36, and becomes a thin liquid film, which is scattered obliquely radially outside the cylindrical body 36. In the structure of this embodiment, since there is no object supporting the collision wall surface 35 in front of the spray, it can be used as the atomizing nozzle of the combustor. In this embodiment, the liquid jet 34 is jetted parallel to the axis of the injector 32, but it is clear that it may be jetted at an angle.

A communication hole 39 for allowing air to flow into a hollow portion 39a formed between the injector 32 and the cylindrical body 36 on the downstream side of the injector 32 in the cylindrical wall portion of the cylindrical body 36.
Has been drilled. The air flow Fa1 flowing in through the communication hole 39 prevents the fuel spray atomized by colliding with the collision wall surface 35 from entering the hollow portion 39a, and when the atomizing nozzle 30 is used in the combustor, Similar to each of the embodiments, the effect of preventing the temperature rise of the wall surface and the retention of the high temperature combustion gas in the vicinity of the atomizing nozzle 30 is exerted. By arranging the central axis of the communication hole 39 in a relationship of a twist position with the axis of the injector 32, the air flow Fa1 flowing through the communication hole 39 can be swirled. By swirling the air flow, an air swirling flow is formed in the hollow portion 39a of the cylindrical body 36, so that the spray can be more effectively pushed forward from the collision wall surface 35 formed at the tip of the cylindrical body 36. You can

In this embodiment, the tip portion 36 of the cylindrical body 36 is
In each of the through holes 38, a slit 40 is provided in each of the through holes 38 near the center axis of the cylindrical body 36 as an airflow passage that is continuous with the hollow portion 39a. The slit 40 preferably has a structure having an arcuate cross section along the outer shape of the through hole 38. In the end wall surface 37 of the cylindrical body 36, the slit 40 has an edge 40 in the through hole 38 as shown in FIG.
Even if the opening is formed so as to be connected in a-shape, FIG.
As shown in, the opening may be left with a slight arc-shaped wall surface 40b. The slit 40 allows the air flow (air) in the hollow portion 39a to be jetted outward from the opening that opens to the end wall surface 37 of the cylindrical body 36. That is, when the liquid film flows out from the collision wall surface 35 into the space, the liquid sometimes sometimes wraps around the end wall surface 37 of the cylindrical body 36. F
By ejecting a2, the liquid is prevented from wrapping around the end wall surface 37, and rather atomization of the liquid is promoted. When the air flow Fa2 is swirled around the axis of the cylindrical body 36 by forming the slit 40 with an inclination in the circumferential direction,
The colliding liquid jet can be further atomized. Also,
By forming the coating layer 40c made of a hydrophobic material on the end wall surface 37 of the cylindrical body 36 and the inner surface of the slit 40, it is possible to further prevent the liquid film from wrapping around.

In each of the embodiments shown in FIGS. 1 to 3, the number of liquid jets 14, 24, 34 is 6, but the injection holes 13, 33 and the collision wall surfaces 15, 25 are arranged so that the number of liquid jets becomes larger. , 3
5 can be configured so that a cone-shaped spray having a shape suitable for combustion can be generated in the same manner as the swirl nozzle.

FIG. 4 is a graph comparing the atomization performances of the wall collision type liquid atomization nozzle according to the present invention and a general air flow atomization nozzle (air brass nozzle) as shown in FIG.
Is shown in. As shown in FIG. 5, the measurement of the atomization performance was carried out by assembling the wall collision type atomization nozzle (the atomization nozzle 10 shown in FIG. 1) and the airflow atomization nozzle coaxially with the air swirler 41, and then the gas turbine combustor. Dome 4 of liner 42
It was done by attaching to 3. The horizontal axis of the performance comparison graph shown in FIG. 4 is the liner differential pressure, and the vertical axis is the representative particle diameter (SMD: average body surface area diameter) of the spray particles. Regarding atomization performance, it is clear that the atomization nozzles 10, 20 and 30 are far superior to the airflow atomization nozzle in that the representative particle size is smaller for a wide range of liner pressure difference. It can be seen that in the atomizing nozzle according to the present invention, the SMD is almost constant regardless of the differential pressure of air. In particular, the atomizing nozzle according to the present invention has a flow rate of SMD of 10 microns, which is several times as large as the flow rate of liquid, and has a pressure of 0.
Since it is possible to generate extremely fine particles that could not be achieved without using a special atomizing nozzle that uses compressed air of 5 MPa or more, for example, in addition to fuel nozzles for combustors such as pesticide sprayers and water droplet generators. Also expected to be used.
That is, according to an experiment by the inventor, when liquid is used as the fuel, the size of the injection hole is reduced to about the size of the injection hole of the diesel fuel injection nozzle, and the fuel injection flow is made to collide with an appropriate collision wall surface. It has been clarified that a jet pressure as small as several tenths of the jet nozzle can generate fine particles that cannot be generated by the air stream atomizing nozzle within the limit of the allowable pressure loss.

[0031]

According to the wall impingement type liquid atomizing nozzle of the present invention, a cylindrical injector having an injection hole for ejecting a pressurized liquid, and an outside of the injector are disposed substantially coaxially with the injector. And a cylindrical body having a collision wall surface against which the liquid jet injected from the injection hole collides,
The liquid jet of the pressurized liquid ejected from the injection hole provided in the injector collides with the collision wall surface provided in the cylindrical body that is arranged substantially coaxial with the injector outside the injector to form a liquid film. , After that, it is atomized by scattering. Therefore, when the wall impingement type liquid atomization nozzle according to the present invention is used in a gas turbine as a liquid, it is impossible with the conventional fuel nozzle for a gas turbine without increasing the pressure loss of the combustor. It is possible to provide an atomizing nozzle that can atomize fine particles.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of a wall collision type liquid atomizing nozzle according to the present invention.

FIG. 2 is a view showing another embodiment of the wall collision type liquid atomizing nozzle according to the present invention.

FIG. 3 is a view showing another embodiment of the wall collision type liquid atomizing nozzle according to the present invention.

FIG. 4 is a graph showing a comparison result of atomization performance between the wall collision type liquid atomization nozzle shown in FIG. 1 and a conventional airflow atomization nozzle.

5 is a view showing a state in which the wall collision type liquid atomizing nozzle shown in FIG. 1 is attached to a gas turbine combustor liner for obtaining the comparison result shown in FIG.

FIG. 6 is a principle diagram of a conventional swirl nozzle.

FIG. 7 is an example of a conventional airflow atomizing nozzle.

[Explanation of symbols]

10, 20, 30 Wall collision type liquid atomization nozzle 11 Fuel 12,32 injector 13,33 injection hole 14, 24, 34 Liquid jet 15,25,35 Collision wall 15a, 40a edge 16,36 cylindrical body 16a Outer peripheral surface of cylindrical body 16b, 40c coating layer 17 Columnar protrusion 19,39 communication holes 20 Tip 21 End wall 38 through hole 40 slits 41 Air swirler 42 gas turbine combustor liner 43 Dome Fa1, Fa2 air flow

Continued front page    F term (reference) 3K056 AA08 AB01 AC01 AD01 AE01                       AE07 BA06                 4F033 AA06 AA13 BA03 CA04 DA05                       EA01 JA02 JA03 KA02 KA03                       NA01 QB02Y QB03X QB12Y                       QB14X QB17 QD02 QD07                       QD09 QD10 QD23 QE05 QE14                       QF07Y QF08X

Claims (10)

[Claims] 1. A cylindrical ejector having an ejection hole for ejecting a pressurized liquid, and a liquid jet ejected from the ejection hole, which is arranged on the outer side of the injector substantially coaxially with the injector and collides with the liquid jet. Wall-collision liquid atomizing nozzle consisting of a cylindrical body with a colliding wall surface. 2. The injection hole of the injector is formed so as to penetrate in a radial direction, and the collision wall surface of the cylindrical body is a circumferential continuous surface formed at a tip end portion of the cylindrical body, or By forming a notch in the distal end portion of the cylindrical body in the circumferential direction or by forming an independent columnar projection at the distal end portion of the cylindrical body, the liquid jets from each of the injection holes individually collide with each other on a discontinuous surface. A wall impingement liquid atomization nozzle according to claim 1, which comprises: 3. The collision wall surface formed on the cylindrical body has a line of intersection with a plane orthogonal to the axis of the cylindrical body represented by a quadratic curve or a part thereof.
The wall impingement type liquid atomization nozzle described in. 4. The wall collision type liquid atomizing nozzle according to claim 3, wherein the collision wall surface is a conical inner wall surface that spreads outward in the nozzle tip direction. 5. The outer peripheral surface of the cylindrical body is connected to the inner wall surface of the cone by an edge, and an air current flowing toward the edge side along the outer peripheral surface of the cylindrical body is flowed. The wall collision type liquid atomizing nozzle according to claim 4. 6. The injection hole of the injector is formed so as to penetrate therethrough in the axial direction, and the collision wall surface is a hole wall surface of a through hole formed at the tip of the cylindrical body. The wall impingement type liquid atomization nozzle according to claim 1. 7. The wall collision type according to claim 6, wherein an airflow passage that opens in a state of being close to or connected to the through hole by an edge is formed at the tip end portion of the cylindrical body. Liquid atomization nozzle. 8. The collision wall surface with which the liquid jet collides has an angle between the normal direction of the collision wall surface and the jet direction of the liquid jet in the range of 110 to 160 degrees. 7. The wall collision type liquid atomizing nozzle according to any one of items 1 to 7. 9. The wall surface according to claim 1, wherein the cylindrical wall of the cylindrical body is formed with a communication hole through which an airflow flows toward the inside of the cylindrical body. Collision type liquid atomization nozzle. 10. The wall impingement type liquid atomization nozzle according to claim 9, wherein the central axis of the opening is in a twisted position relationship with the axis of the injector.