JP2001327896A - Two fluid atomizing spray nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two fluid atomizing spray nozzle capable of attaining atomization having large capacity and small particle diameter with the small quantity of air. SOLUTION: Pressurized air introduced from an air introducing flange 1 is divided into primary air flowing in an air flow-in port 5 in the center side and a secondary air flowing in an air flow-in port 6 in the side surface side, the primary air is mixed with pressurized water introduced from a body 9 in a mixing part 12 to jet the mixture as sprayed water from a nozzle hole 14 and the secondary air is introduced into a passage 20 and collides with the sprayed water jetted from a nozzle hole 14 from the side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray nozzle for atomizing and spraying a liquid, and more particularly to a large-capacity two-fluid atomizing spray suitable for spraying atomized droplets into the intake of a compressor of a gas turbine. Regarding the nozzle.

[0002]

2. Description of the Related Art A nozzle that sprays a liquid by atomizing (atomizing) the liquid by using the pressure of a gas such as air is known as a type of nozzle for spraying a liquid such as water, chemical liquid, or liquid fuel. It is called a two-fluid atomizing spray nozzle, and various commercial products can be seen.

A specific example of this type of nozzle is disclosed in, for example, Japanese Patent Application Laid-Open No. 57-27158, in which water is injected into a high-speed air stream without using a steam-water mixer, and water is injected by the air stream. Disclosed is a nozzle that is atomized and sprayed in a conical shape.

Japanese Patent Application Laid-Open No. Sho 61-171561 discloses a spray nozzle for a paint in which a flat spray pattern is formed so that the spray direction can be changed. Discloses a nozzle in which a gas and a liquid are mixed in a nozzle and ejected from a slit (orifice) at the tip of the nozzle to obtain finer sprayed liquid.

[0005] In recent years, a combined cycle power generation system using a gas turbine has been widely adopted from the viewpoint of overall thermal efficiency. However, in a system using such a gas turbine, the intake air temperature is generally increased. There is a characteristic that the output decreases as the temperature rises and the thermal efficiency also decreases.

Therefore, in order to cope with the influence of such a rise in the intake air temperature, when the air temperature is high in summer or the like,
For example, a method in which water atomized to a particle diameter of less than 20 μm is injected into the intake air, the rise in the intake air temperature is suppressed by the heat of evaporation, and the mass flow rate of the fluid acting on the turbine has been conventionally adopted, At this time, a two-fluid atomizing spray nozzle using a high-pressure air taken out of a compressor of a gas turbine may be used.

In this case, although it depends on the capacity of the gas turbine, it is necessary to spray a considerably large amount of water into the air chamber on the upstream side of the compressor. Water is sprayed all at once from the nozzle.

For example, in recent years, a system using a gas turbine having a large output of several hundred megawatts has appeared. In this case, the amount of water sprayed per hour is 4 times.
An atomizing spray nozzle having a large capacity of 2 liters (700 milliliters per minute) is used, and several hundred nozzles are used to meet the demand.

[0009]

In the above prior art, it cannot be said that consideration is given to the air / water ratio which is the ratio of the amount of air required for spraying and the amount of water to be sprayed. Had a problem. Here, important issues required for a two-fluid atomizing spray nozzle that can be used in such a gas turbine power generation system include the following.

Problem 1. Low air / water ratio and low air volume used by the two-fluid atomizing spray nozzle. Reason: In the gas turbine system, the air used in the two-fluid atomizing spray nozzle is supplied from the compressor of the gas turbine, so the air used in the nozzle becomes a loss from the viewpoint of the gas turbine, and the thermal efficiency is reduced. For.

Problem 2. Able to spray as much water as possible. Reason: To be easily applicable to a large number of gas turbine systems with a small number.

Problem 3. The size of the sprayed water droplets can be atomized to a Sauter average particle size of less than 20 μm. Reason: If the particle size is large, it will not get on the airflow flowing into the compressor well, and the evaporation will be delayed, so that it will be sucked into the compressor as water droplets, causing erosion, and sufficient latent heat of vaporization in the compressor Because it cannot be robbed, the degree of contributing to a decrease in air temperature decreases, and the degree of contribution to improving thermal efficiency decreases.

The Sauter mean particle size is a general index when the particle size of the spray water is expressed by a laser measurement method.
It is desired that the particle size is less than m and at least 16 μm or less.

On the other hand, in the prior art, for example, the amount of atomized water is 4
With 2 liters / hour and a Sauter mean particle size of about 16 μm, the air-water ratio, ie the ratio of air usage to atomized water volume, is 420.

An object of the present invention is to provide a two-fluid atomizing spray nozzle capable of obtaining a large volume, small particle size spray with a small amount of air.

[0016]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a two-fluid atomizing spray nozzle of the type in which a liquid is atomized and sprayed using a pressurized gas. The gas diverted to the one system is mixed with the liquid to be sprayed and sprayed from the nozzle hole, and the gas diverted to the other system is
This is achieved by colliding the spray pattern ejected from the nozzle holes from both sides as a counter flow.

Another object of the present invention is to provide a two-fluid atomizing spray nozzle of the type in which a liquid is atomized and sprayed using a pressurized gas, in which the gas supplied to the nozzle is divided into one system and the other system. The gas diverted to the one system is mixed with the liquid to be atomized and sprayed and ejected from the nozzle hole, and the gas diverted to the other system is misaligned with the spray pattern ejected from the nozzle hole. This is also achieved by colliding from both sides as counterflow.

At this time, the above object can be achieved even if the member having the nozzle hole is covered with a cap having a conical cavity, and the nozzle hole is opened at the bottom of the cavity.

The flow rate of the gas diverted to the one system is denoted by A, and the flow rate of the gas diverted to the other system is denoted by B.
Then, even if the relationship of A <B is established, the above object can be achieved.

Further, the above object can be achieved by providing two air blocking plates arranged at a predetermined distance from each other in the opening of the cavity of the cap. The above object can be achieved even if the shape of the opening that is ejected as a counter flow is any one of a T shape, an L shape, a rectangle, a triangle, a pentagon, and a hexagon.

At this time, the nozzle is provided with the following water droplet refining function, whereby the above object can be achieved. (1) A miniaturization function provided by mixing air and water and jetting them out of small holes, and scattering them at a high flow rate. (2) A miniaturization function by applying air to the sprayed water droplets and applying a shear force to the water droplets. (3) Refinement function by changing the direction of sprayed water droplets and applying shear force to the water droplets.

(4) A fine function by applying a rotational force to the sprayed water droplets and applying a centrifugal force to the water droplets. (5) A miniaturization function by colliding the sprayed water droplets with each other and impacting the water droplets. (6) A miniaturization function by inducing ultrasonic waves by collision of sprayed water droplets.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a two-fluid atomizing spray nozzle according to the present invention will be described in detail with reference to the illustrated embodiments. First, FIG. 1 is an explanatory view showing a first embodiment of the present invention. Here, FIG. 1 (a) is a side sectional view, in which a two-fluid atomizing spray nozzle according to this embodiment is used. The atomizing air having a predetermined pressure is supplied into the nozzle from the air pipe mounting portion of the air introducing flange 1.

The air that has flowed into the air introduction flange 1 enters a space 4 in the nozzle formed by the packing 2 and the air branch flange 3, where the primary air that flows into an air inlet 5 at the center is provided. And secondary air flowing into the air inlet 6 on the side.

At this time, the flow rate of the secondary air flowing into the air inlet 6 is restricted by the small holes 8 of the orifice distribution plate 7, and the branch distribution with the primary air is determined. The air is about 1 /
At 3, the secondary air is determined to be about 2/3.

On the other hand, the water to be sprayed is supplied at a predetermined pressure from the inlet of the body 9 into the nozzle, passes through the opening 10 and passes through the gap 11 formed by the air branch flange 3 and the body 9. The water enters the air / water mixing section 12 (mixer), where it is mixed with the primary air that has flowed in from the air inlet 5 and jetted out of the nozzle hole 14 at the spray water jetting terminal 13.

FIG. 2 (b) schematically shows the state of water spouting at this time. As shown in FIG. 2, the mixture of water and primary air is sprayed as conical spray water from the nozzle hole. At this time, the pressure of the mixed primary air and the pressure of the water itself give the function of miniaturizing water droplets shown in (1) above,
It is atomized.

On the other hand, an air reservoir 18 is formed on the end surface of the body 9 by an outer peripheral portion of the spray water jet terminal 13, an inner peripheral portion of the cap 16, an inner surface of the end surface, and a packing 17. In the drawing, it flows out from the opening 15 at the end of the body 9 on the right side, flows into the air reservoir 18, and further flows into the passage 20.

At this time, as shown in FIG. 1 (b), the surface of the spray water jetting terminal 13 where the nozzle hole 14 is opened has an axis perpendicular to the center axis of the nozzle hole 14 as a center. Along the side, a slit 19 having a rectangular cross section is formed. The inner surface of the end face of the cap 16 abuts on the cap 16, thereby forming the passage 20.

Therefore, the passage 20 is provided on the outside with the air reservoir 18.
The hole is opened at a right angle to the center axis of the small hole 14 which is open to the spray water jetting terminal 13 at the inside, and is opposed to each other.

Then, the secondary air flowing into the air reservoir 18 becomes mutually countercurrent when ejected from the opening of the passage 20, sandwiching the spray water ejected conically from the small hole 14, Secondary air will be made to collide from both sides right beside it.

Here, in FIG. 1 (b), although the orthogonal axis looks oblique, it is assumed here that it is horizontal. FIG. 1C is a perspective view of the cap 16 as viewed from the outside.

FIGS. 2 (c) and 2 (d) schematically show the situation at this time. As shown in FIG. 2 (b), the spray water sprayed in a conical shape from the nozzle hole 14 is used. As shown in Figs. 2 (c) and 2 (d), the spraying water, which had a conical distribution due to the primary air and water, spread fan-shaped up and down in the vertical direction. A spray distribution is obtained, whereby each of the miniaturization functions shown in the above (2), (3), (5) and (6) works, and water droplets can be made finer.

Here, the flow of water and air in the two-fluid atomizing spray nozzle of FIG. 1 is schematically shown as a whole as shown in FIG. 2 (a). Therefore, according to this embodiment, , The miniaturization function by mixing and jetting the primary air and water, and the miniaturization function by colliding the secondary air from both sides of the sprayed water pattern directly , And sufficient formation of fine water droplets can be obtained.

The cross-sectional shape of the slit 19 in this embodiment is typically the rectangular shape shown in FIG. 1, but is not limited to this. First, FIG.
FIG. 4 shows an example of a slit 19 having a T-shape in an oncoming collision.
Shows the shapes of two types of slits in addition to the rectangular shape, and the present invention can be implemented by slits having any of these cross-sectional shapes. Water particle size, processing cost,
What is necessary is just to determine according to the magnitude | size of the dust contained in air, etc.

Next, a second embodiment of the two-fluid atomizing spray nozzle according to the present invention will be described with reference to FIG. Here, also in the second embodiment, as shown in FIG. 5A, the overall cross-sectional shape is the same as that of the first embodiment shown in FIG. There is no change in the components of each part including the cap 16 shown in FIG.

Therefore, even in the two-fluid atomizing spray nozzle according to the second embodiment, the flow of water and air is as shown in FIG. The atomization function caused by the application of the secondary air to the spray water works in duplicate to double the water droplets.

The situation at this time is also as shown in FIGS. 2 (c) and 2 (d). As shown in FIG. 2 (b), as shown in FIG. By spraying air from the side, as shown in the figure, the spray water, which already had a conical distribution due to the primary air and water, is turned into a spray distribution in which the spray area spreads in a fan-shape.
Each of the miniaturization functions shown in (2), (3), (5), and (6) works to obtain fine particles.

The two-fluid atomizing spray nozzle according to the second embodiment shown in FIG. 5 is different from the two-fluid atomizing spray nozzle according to the first embodiment shown in FIG. As shown in FIG. 5B, the slit 19 is provided along both sides of the orthogonal axis.

As a result, in the second embodiment, the slits 19 on both sides of the center axis of the nozzle hole 14 are formed.
Are not opened directly opposite to each other, but are opened in the form of rubbing each other and facing each other.

Then, in the first embodiment described with reference to FIG. 1, since the secondary air is in a counter-flow with the spray water sprayed in a conical shape, this is called a counter-flow method. In this case, in the embodiment shown in FIG. 5, they face each other so that they face each other, so to speak, it can be called a mutual counterflow method.

FIG. 6 schematically shows the situation due to the secondary air at this time. As shown in this figure, in this case, the secondary air is caused to collide with the spray water as a mutually countercurrent flow. As a result, a force in the rotation direction is applied to the spray water jetted with a conical spray distribution by the primary air and water.

The orthogonal axis at this time is inclined by a predetermined angle R from the vertical direction as shown in the figure, and as a result, the spray water jetted with a conical spray distribution spreads up and down. It is transformed into a fan shape, resulting in a spray distribution with a wide spray range.

Therefore, according to the second embodiment, in addition to the miniaturization functions shown in the above (2), (3), (5) and (6),
Further, the miniaturization function shown in the above (4) can be obtained, and the particle size of the water droplet can be further reduced.

Also, in this case, since the secondary air is colliding with the spray water as a countercurrent flow, the spray water is scattered so as to rotate in the circumferential direction and acceleration is reduced, so that the flight distance is shortened. The range becomes wider, and the flight distance characteristic differs from that of the nozzle described with reference to FIG.

Here, also in the second embodiment, the sectional shape of the slit 19 is not limited to a rectangle. For example, FIG.
Is an example in which the slit 19 is formed in an L-shape. Even in this case, as shown in FIG. 6, in order to obtain a spray distribution extending in the vertical direction, the orthogonal axis of the slit 19 is slightly shifted by an angle R. It is necessary to incline as described above.

FIG. 8 is an example of three types of slits other than the L-shaped slit. The selection of the cross-sectional shape of these slits is also the same as in the first embodiment described above. It is determined by the particle size, processing cost, and the size of dust contained in the air.

By the way, in the embodiment using the slit of the oppositely facing method described with reference to FIG. 5, a sufficiently fine spray of water droplets can be obtained. Among the secondary air ejected from 19, there is ineffective air that escapes to the outside of the spray water and does not effectively act on miniaturization of water droplets.

FIG. 10 shows an embodiment of the present invention in which the invalid air can be effectively used. As shown, a part of a conical cavity formed in the cap 16 is closed. In this manner, two air blocking plates 21 are provided on the tip end surface of the cap 16 so as to sandwich the nozzle hole 14 from both sides and leave a predetermined interval L. This is the same as the embodiment shown in FIG.

At this time, as shown in FIG. 11, the width of the interval L by the air blocking plate 21 is set to a size just before the spray water pattern spreading in a fan shape. As a result, the invalidated air is allowed to pass through the spray water pattern, and the secondary air is effectively used, so that further refinement is achieved.

Next, the results of measuring the performance of the two-fluid atomizing spray nozzle according to the embodiment of the present invention will be described. Here, FIG. 12 shows an example of a measurement result in the case of using the opposed collision T-shaped slit shown in FIG. 3 in the two-fluid atomization spray nozzle by the opposed flow method of FIG. 7 shows the measurement results when the opposed-swept L-shaped slit shown in FIG. 7 is used for the nozzle of the opposed-swept flow method shown in FIG. 5 and the air blocking plate 21 shown in FIGS. 10 and 11 is further installed. An example is shown.

In these figures, the horizontal axis represents the amount of sprayed water, and the vertical axis represents the air-water ratio (volume flow rate of air / volume flow rate of water) and the average particle diameter of the Sauter.
g / cm ² G.

From the measurement results of FIGS. 12 and 13, in the embodiment of the present invention, both are the same in that a spray having a fine particle diameter is obtained.
Although slightly, the facing friction L with the air blocking plate 21 installed
It can be seen that in the mold slit, the water droplet diameter is small where the amount of spray water is large.

In comparison with the characteristics of the two-fluid atomizing spray nozzle according to the prior art, according to the prior art, as described above, the spraying water amount is 700 cc / min (42 liters / hour), In the case of a diameter of 16 μm, the air-water ratio is 420, whereas in the embodiment of the present invention, both are almost the same in terms of performance,
Even if the particle size is the same as in the prior art, the air / water ratio is about 300, and therefore, the amount of air can be reduced by about 30% as compared with the prior art.

Therefore, according to the embodiment of the present invention, all of the above-mentioned problems are solved, and by applying the present invention to a gas turbine power generation system, the loss can be suppressed, which can greatly contribute to improvement in efficiency.

[0056]

According to the present invention, the miniaturization function by ejecting the primary air and water and the miniaturization function by applying the secondary air to the jetted spray water work dually. Therefore, it is possible to easily provide a two-fluid atomizing spray nozzle having a sufficiently low air-water ratio while maintaining sufficient atomization of spray water droplets and large capacity of spray water.

As a result, according to the present invention, since the amount of air used can be sufficiently suppressed, the present invention can be applied to a gas turbine power generation system and greatly contribute to the improvement of the efficiency.

Further, according to the present invention, two types of two-fluid atomizing spray nozzles having a large capacity and different flight distances can be obtained. By combining them, the spray distribution can be arbitrarily selected. And as a result, if necessary,
A uniform and wide distribution can be easily formed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a two-fluid atomizing spray nozzle according to the present invention.

FIG. 2 is a schematic diagram for explaining an operation according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating an example of a slit shape according to an embodiment of the present invention.

FIG. 4 is an explanatory view showing various examples of a slit shape in one embodiment of the present invention.

FIG. 5 is an explanatory view showing another embodiment of the two-fluid atomizing spray nozzle according to the present invention.

FIG. 6 is a schematic diagram for explaining an atomizing operation according to another embodiment of the present invention.

FIG. 7 is an explanatory view showing an example of a slit shape according to another embodiment of the present invention.

FIG. 8 is an explanatory view showing various examples of a slit shape according to another embodiment of the present invention.

FIG. 9 is a schematic diagram for explaining an atomizing operation according to another embodiment of the present invention.

FIG. 10 is a perspective view of a cap according to still another embodiment of the present invention.

FIG. 11 is a front view of a cap according to still another embodiment of the present invention.

FIG. 12 is a characteristic diagram of air-water ratio and particle diameter according to an embodiment of the present invention.

FIG. 13 is a characteristic diagram of the air-water ratio and the particle diameter according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air introduction flange 2 Packing 3 Air branch flange 4 Space 5 Air inlet (center) 6 Air inlet (side) 7 Orifice distribution plate 8 Small hole 9 Body 10 Opening 11 Gap 12 Mixing part (Mixer) 13 Spray water jet Terminal 14 Nozzle hole 15 Opening 16 Cap 17 Packing 18 Air reservoir 19 Slit 20 Passage 21 Air blocking plate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidetoshi Karasawa 7-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Power & Electric Development Laboratory, Hitachi, Ltd. (72) Eitaro Murata Inventor Eitaro Murata 3-1-1, Machi F-term in Hitachi, Ltd. Thermal and Hydro Power Division 4F033 QB02Y QB03X QB12Y QB15X QB17 QD02 QD15 QD19 QD25 QE13

Claims (6)

[Claims] 1. A two-fluid atomizing spray nozzle of a type in which a liquid is atomized and sprayed using a pressurized gas, wherein the gas supplied to the nozzle is divided into one system and the other system, and The gas diverted to the system is mixed with the liquid to be atomized and sprayed and ejected from the nozzle hole, and the gas diverted to the other system is applied to the spray pattern ejected from the nozzle hole as a counterflow. A two-fluid atomizing spray nozzle characterized by being configured to collide from both sides. 2. A two-fluid atomizing spray nozzle of a type in which a liquid is atomized and sprayed by using a pressurized gas, wherein the gas supplied to the nozzle is divided into one system and the other system, The gas diverted to the system is mixed with the liquid to be atomized and sprayed and ejected from the nozzle hole, and the gas diverted to the other system is sprayed from the nozzle hole, and the gas is scattered as a counterflow. A two-fluid atomizing spray nozzle characterized by being configured to collide from both sides. 3. The invention according to claim 1, wherein the member having the nozzle hole is covered with a cap having a conical cavity, and the nozzle hole is opened at the bottom of the cavity. A two-fluid atomizing spray nozzle, characterized in that: 4. The invention according to claim 1, wherein the flow rate of the gas diverted to the one system is A, and the flow rate of the gas diverted to the other system is B. <A two-fluid atomization spray nozzle configured to satisfy the relationship of B. 5. The invention according to claim 3, wherein two air blocking plates arranged at a predetermined interval from each other are provided in the opening of the cavity of the cap. Two-fluid atomizing spray nozzle. 6. The invention according to claim 1 or 2, wherein the shape of the opening from which the secondary air is jetted in the counterflow is T-shaped, L-shaped, rectangular, triangular, pentagonal, hexagonal. A two-fluid atomizing spray nozzle, characterized in that it is configured to be any one of the above.