WO2014024813A1

WO2014024813A1 - Spray nozzle, and burner and combustion device equipped with same

Info

Publication number: WO2014024813A1
Application number: PCT/JP2013/071102
Authority: WO
Inventors: 洋文岡▲崎▼; 倉増　公治; 英雄沖本; 折井　明仁; 健一越智
Original assignee: バブコック日立株式会社
Priority date: 2012-08-06
Filing date: 2013-08-05
Publication date: 2014-02-13
Also published as: KR20150036393A; KR101591634B1; JP6029375B2; EP2881662A4; EP2881662B1; JP2014031990A; EP2881662A1

Abstract

The present invention provides a spray nozzle with which atomization of a spray fluid can be promoted and the amount of a spray medium used, as well as the pressurization of the spray medium, can be reduced. This spray nozzle is characterized by being equipped with: at least two spray fluid flow paths in which a spray fluid flows; at least two spray medium flow paths that converge with a respective spray fluid flow path at a first convergence part; at least two mixed fluid flow paths in which the fluid mixture of the spray fluid and the spray medium that have converged at the respective first convergence parts flows, and which are formed opposing one another and have a second convergence part in which the fluid mixture becomes opposing flows that collide and converge; and an outlet hole from which the fluid mixtures that have converged at the second convergence part is sprayed. In addition, bend parts that change the direction of flow of the mixed fluid are formed in the mixed fluid flow paths, in the interval between the first convergence parts and the second convergence part.

Description

Spray nozzle, burner equipped with the same, and combustion apparatus

The present invention relates to a spray nozzle, a burner including the spray nozzle, and a combustion apparatus, and more particularly to a spray nozzle suitable for atomizing a spray fluid (liquid) using a spray medium (gas) and a burner including the spray nozzle. And a combustion apparatus.

Generally, in a high-output and high-load combustion apparatus such as a power generation boiler, a floating combustion method that horizontally burns fuel is often employed. When liquid fuel is used as the fuel, the fuel is atomized by a spray nozzle and burned in a furnace in a combustion apparatus.

The spray nozzle as described above is used for combustion of auxiliary fuel for starting and flame stabilization in a combustion apparatus using solid fuel as a main fuel, such as pulverized coal, in addition to a combustion apparatus using liquid fuel as a main fuel. Often installed.

In the combustion of liquid fuel, if the spray particle size is large, the combustion reaction is delayed, and the combustion efficiency is lowered and soot, carbon monoxide, and nitrogen oxides are likely to be generated. Also, liquid fuel is poorly mixed with combustion air, and if the combustion air around the spray particles is insufficient, soot and carbon monoxide are likely to be generated.

For this reason, in the combustion of liquid fuel, it is necessary to pay attention to atomization and mixing with combustion air.
Further, in a high-output, high-load combustion apparatus, so-called large capacity is required in which the amount of liquid fuel sprayed per spray nozzle is increased.

As a type of the spray nozzle, there is a two-fluid spray method in which air or steam is supplied as a spray medium for atomization in addition to the spray fluid and is atomized by mixing with the spray fluid.

This two-fluid spraying method has good atomization even with a large volume of spray compared to spraying with only the spray fluid, and is generally used in high-load combustion devices such as boilers for power generation. It is a problem to reduce the amount of spraying and the amount of pressurization of the spray fluid and spray medium during spraying.

For example, when steam is used as the spraying medium, the steam introduced into the combustion apparatus becomes moisture in the combustion exhaust gas. When the amount of exhaust gas increases due to this moisture, the thermal efficiency in the combustion device decreases.

For this reason, it is desirable to reduce the amount of steam used within a range that does not hinder atomization of liquid fuel. Further, although the spray fluid and the spray medium are pressurized during spraying, energy consumption can be reduced by reducing the pressurization amount.

In order to solve the above problems, in the two-fluid spray method, a method for mixing a spray medium has been studied.

Among these, the mixed fluid after mixing the spray fluid and the spray medium is supplied in opposition to the vicinity of the outlet hole provided at the tip of the spray nozzle and atomized by colliding the flow of the opposed mixed fluid. An example of promoting is described in Patent Document 1.

In the above-mentioned Patent Document 1, the spray medium is mixed with the spray fluid in the flow path upstream of the spray nozzle outlet hole, and the mixed fluid is collided in the vicinity of the outlet hole. By using a mixed fluid of the spray medium and the spray fluid, the collision force of the spray fluid becomes stronger and finer than in the case of a single fluid.

Also, as a method for achieving both a large capacity for increasing the spray amount of liquid fuel per spray nozzle and atomization of the liquid fuel, a method of increasing the number of outlet holes provided at the tip of the spray nozzle is common. By increasing the outlet holes of the spray nozzle, the capacity can be increased without increasing the size of the individual outlet holes.

Patent Document 2 can be cited as an example of the spray nozzle having a plurality of outlet holes of the spray nozzle. Patent Document 2 describes an example of a so-called intermediate mixing type spray nozzle that mixes a spray fluid and a spray medium in the middle of a flow path.

Also, Patent Document 3 describes an example of a so-called internal mixing type spray nozzle in which a spray fluid and a spray medium are mixed in a space upstream of a spray nozzle outlet hole.

JP 9-239299 A JP 62-112905 A JP-A-62-186112

The above-described two-fluid spray nozzle described in Patent Document 1 is provided with a spray fluid (liquid) channel inside the spray nozzle and a spray medium (gas) channel at the outer peripheral position thereof. The flow direction of the spray fluid and the spray medium is changed by the partition wall surrounding the outlet hole provided at the tip of the spray nozzle, and both the flow paths intersect to mix the spray fluid and the spray medium. The flow path of the mixed fluid is configured to be opposed in the vicinity of the outlet hole of the spray nozzle.

At this time, atomization of the spray fluid proceeds due to the following three effects.

(1) Atomization by colliding with the partition wall at the junction where the flow path of the spray fluid intersects the flow path of the spray medium and the two meet.

(2) Atomization by mixing spray fluid and spray medium.

(3) Atomization due to collision of the mixed fluid flowing in the vicinity of the outlet hole of the spray nozzle.

However, the above (1) and (2) are contradictory items because the other weakens when trying to strengthen one. That is, when the momentum of the spray fluid is increased and the effect of (1) is increased, the momentum of the spray medium is relatively weaker than that of the spray fluid, and the effect of (2) is weakened due to delay in mixing. On the contrary, if the flow rate and flow velocity of the spray medium are increased and the effect (2) is increased, the spray fluid is less likely to collide with the partition walls, and the effect (1) is weakened.

Furthermore, after mixing the spray fluid and the spraying medium, there is a problem that the distance from the spray nozzle outlet hole to the spray nozzle is short, and it is difficult to uniformly mix them. When both are not mixed uniformly, atomization deteriorates in a portion where the ratio of the spray medium is small. In this case, in order to promote atomization, it is necessary to increase the amount of spray medium used or increase the pressure.

Next, as a problem of increasing the capacity to increase the spray amount of the liquid fuel per spray nozzle due to the porosity, deterioration of atomization performance when a part of the spray nozzle outlet hole is blocked and blockage of the flow path are mentioned. .

Hereinafter, this will be described with reference to

Patent Documents

2 and 3 described above.

In other words, in the case of the intermediate mixing type described in Patent Document 2, when one of the spray nozzle outlet holes is blocked or partially blocked by impurities or deposits in the spray fluid or spray medium, the blocked outlet hole is blocked. The flow of the spray fluid or spray medium connected to the flow stops or slows down.

When the flow of the flow path of the spray fluid or the spray medium is stopped or slowed, the liquid fuel flowing as the spray fluid is heated by the radiant heat from the inside of the combustion apparatus, and the solid content in the liquid fuel may be deposited. When the solid content in the liquid fuel is deposited, the flow path is closed, and the closed section expands to the upstream side of the flow path, making maintenance difficult.

On the other hand, in the case of the internal mixing type described in Patent Document 3, even if one of the spray nozzle outlet holes is closed, the spray fluid and the spray medium are ejected from the other outlet holes, so the upstream flow path The possibility of obstruction is small.

However, since Patent Document 3 has a wide space (mixing chamber) in which the spray fluid and the spray medium are mixed, if a part of the spray nozzle outlet hole is blocked, the flow state in the mixing chamber changes, and the spray fluid and the spray medium It is difficult to maintain a constant ratio.

For this reason, there is a problem that the ratio of the atomizing medium in the mixed fluid differs depending on the atomizing nozzle outlet hole, and the atomization characteristics also change.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a spray nozzle capable of promoting atomization of a spray fluid and reducing both the amount of spray medium used and the pressure applied. An object of the present invention is to provide a burner including the same and a combustion apparatus.

In order to achieve the above object, the spray nozzle of the present invention has at least two spray fluid passages through which the spray fluid flows, and a spray medium flows, and joins at each of the spray fluid passages and the first junction. The mixed fluid of the spraying fluid and the spraying medium merged in at least two spraying medium flow paths and the respective first merging portions flows, and is formed to face each other, so that the mixed fluid becomes a facing flow. At least two mixed fluid flow paths having a second merge section that collides and merges, and an outlet hole that ejects the mixed fluid merged at the second merge section, A bent portion that changes a flow direction of the mixed fluid is formed between the first merging portion and the second merging portion.

In order to achieve the above object, the burner of the present invention is a burner that uses liquid fuel as fuel, uses the spray nozzle having the above-described configuration, and uses the liquid fuel as the spray fluid as a tip of the spray nozzle. Supplying steam or compressed air to the tip of the spray nozzle as the spray medium,
Alternatively, a burner having a fuel nozzle for ejecting solid fuel and its carrier gas, a spray nozzle for spraying liquid fuel, and a combustion gas nozzle for ejecting combustion gas for burning the solid fuel or liquid fuel, As the spray nozzle, the spray nozzle configured as described above is used, the liquid fuel is supplied as the spray fluid to the tip of the spray nozzle, and the vapor or compressed air is supplied as the spray medium to the tip of the spray nozzle. It is characterized by.

In order to achieve the above object, the combustion apparatus of the present invention is a combustion apparatus for burning a solid fuel and a liquid fuel, a combustion furnace for burning the fuel, and a solid fuel for supplying the solid fuel to the combustion furnace A supply system; a liquid fuel supply system for supplying liquid fuel to the combustion furnace; a combustion gas supply system for supplying combustion gas to the combustion furnace; and the fuel supply system and the combustion gas supply system. A plurality of burners for burning the solid fuel or liquid fuel provided on the furnace wall of the combustion furnace; a heat exchanger for recovering heat from the combustion exhaust gas generated in the combustion furnace; and A flue for supplying to the outside of the combustion furnace, and one of the burners uses the burner having the above-described configuration.

According to the present invention, there is an effect that it is possible to achieve both the promotion of atomization of the spray fluid and the reduction of the amount of spray medium used and the reduction of the applied pressure.

It is sectional drawing which shows schematic structure of the burner using the spray nozzle of this invention. It is a figure which shows schematic structure of the combustion apparatus provided with the spray nozzle of this invention. Example 1 of the spray nozzle of the present invention is shown, and is a cross-sectional view of the tip of the spray nozzle. It is a longitudinal cross-sectional view of FIG. It is a characteristic figure which shows an example of the atomization performance in Example 1 of the spray nozzle of this invention, and shows the relationship between the bending part change angle of a mixed fluid flow path, the average particle diameter of spray, and a pressure loss ratio. Example 2 of the spray nozzle of this invention is shown, and it is sectional drawing of the spray nozzle front-end | tip part. It is sectional drawing of FIG. Example 3 of the spray nozzle of the present invention is shown and is a plan view of the tip of the spray nozzle. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG.

Hereinafter, based on the illustrated embodiment, the spray nozzle of the present invention, the burner including the spray nozzle, and the combustion apparatus will be described. In each embodiment, the same reference numerals are used for the same parts.

FIG. 1 shows an example of a burner equipped with the spray nozzle of the present invention, and FIG. 2 shows an example of a combustion apparatus equipped with the burner.

As shown in FIG. 1, the burner 20 of this embodiment has a central axis 21 through which a spray nozzle 1 and a spray fluid (liquid fuel) and a spray medium (such as steam or compressed air) flow. An obstacle 22 for stabilizing the flame is provided near the tip of 21. The fuel is injected from the spray nozzle 1 to form a fan-shaped spray 23. The obstacle 22 is generally a swirling flow generator or a baffle plate having a slit.

On the other hand, the combustion air is supplied from the wind box 24 in three flow paths. That is, the three flow paths are the primary flow path 25, the secondary flow path 26, and the tertiary flow path 27 from the side closer to the spray nozzle 1 at the center of the burner 20, and the primary flow path 25, the secondary flow path From the flow path 26 and the tertiary flow path 27, the primary air 28, the secondary air 29, and the tertiary air 30, respectively, are jetted into the furnace 31 as combustion air.

Further, the combustion air is changed in the direction of jetting of the combustion air by the swirling

flow generators

32 and 33 and the guide plate 34, so that generation of soot and NOx is suppressed. The flow rate of the combustion air is controlled by dampers (not shown) provided in the flow paths.

Furthermore, the burner 20 is connected to a furnace wall 35, and a heat transfer tube 36 is provided on the furnace wall 35 for heat recovery. As shown in FIG. 2, a plurality of burners 20 are installed on the furnace wall 35 (two locations in FIG. 2). Each burner 20 has a combustion air supply system 41, a liquid fuel supply system 42, and a spraying fuel. A medium supply system 43 is connected.

In the present embodiment, the combustion air supply system 41 is branched into a pipe 45 connected to the burner 20 and a pipe 46 connected to the air supply port 44 on the downstream side thereof. A flow control valve (not shown) is connected. The liquid fuel supply system 42 and the spray medium supply system 43 are connected to a supply device (not shown) for adjusting pressure and flow rate on the upstream side, and the spray nozzle 1 is installed at the downstream end thereof. ing.

In this embodiment, the spray nozzle 1 is characterized in that a bent portion whose flow direction changes is provided in the mixed fluid flow path between the outlet from the mixing portion for mixing the spray fluid and the spray medium. Yes.

Hereinafter, the spray nozzle 1 of the present embodiment will be described with reference to FIGS. 3 and 4.

As shown in FIG. 3, the spray fluid 2 and the spray medium 3 in this embodiment pass through the independent spray fluid channels 4 and 5 and the spray medium channels 6 and 7 constituting the spray nozzle 1 and spray. Mixing is performed in the middle of the fluid flow paths 4 and 5. The mixed fluid 8 of the spray fluid 2 and the spray medium 3 passes through the mixed

fluid flow paths

9 and 10 that flow opposite to each other, collides in the vicinity of the outlet hole 11 of the spray nozzle 1, and is ejected from the outlet hole 11. .

The mixed fluid 8 ejected from the outlet hole 11 forms a fan-shaped spray in a direction perpendicular to the flow direction of the mixed fluid channels 9 and 10 (the direction in which the mixed fluid channel extends) due to a collision near the outlet hole 11. Is done. A groove portion 12 is formed in the outlet hole 11 of the spray nozzle 1 in the same direction as the fan-shaped spray formation direction, and an intersection portion of the groove portion 12 and the mixed

fluid flow paths

9 and 10 becomes the outlet hole 11.

The atomizing fluid 2 is atomized by mixing with the atomizing medium 3 and becomes a thin liquid film by the collision of the mixed fluid 8 at the outlet hole 11, and the liquid film is split by the shearing force with the surrounding gas after being ejected from the outlet hole 11. And atomize.

Such a spraying method that atomizes by the impact force of the fluid is generally referred to as fan spraying.

In the fan spray type spray, since the mixed fluid 8 flowing through the flow mixed

fluid flow paths

9 and 10 facing each other collides in the vicinity of the outlet hole 11, the fluid spreads in a right angle direction, so the momentum of the spray decreases. In particular, the spray tends to spread on the outer periphery of the spray, and a thin liquid film is formed, so that the number of fine particles (diameter less than 100 μm) increases. Due to the low momentum, the fine particles tend to stay near the spray nozzle. Particles that have been atomized to a diameter of less than 100 μm, preferably 50 μm or less (hereinafter referred to as “fine particles”) have a large surface area in the volume, and are likely to burn by being heated by heat radiation from the furnace.

For this reason, by retaining these fine particles in the vicinity of the spray nozzle 1, the ignition of the spray is accelerated, contributing to the stabilization of the flame and the promotion of the combustion reaction.

Note that the degree of atomization can be adjusted by the pressure of the mixed fluid and the amount of the spray medium (ratio of the spray medium to the spray fluid).

On the other hand, since the central portion of the fan spray type spray has a larger flow rate than the outer peripheral portion and the spray is difficult to spread, a thick liquid film is formed compared to the outer peripheral portion. For this reason, there are many large particles (diameter 100 to 300 μm). Large particles have a higher momentum than fine particles and are easy to mix with combustion air flowing in a distant position, but the combustion reaction is delayed as compared with fine particles.

For this reason, it is necessary to promote atomization not only by collision of the mixed fluid but also by mixing with a spraying medium.

However, since the spray fluid 2 and the spray medium 3 have different densities and viscosities, it may be difficult to mix them. In particular, when the mixed

fluid flow paths

9 and 10 are short and linear, it can be considered that both flow to the outlet hole 11 without mixing.

In this case, although the portion of the mixed fluid 8 where the ratio of the spraying medium 3 is high is atomized, the portion where the ratio of the spraying medium 3 is low is not atomized and large particles are likely to be generated.

Therefore, the spray nozzle 1 of the present embodiment is a mixture that is formed to face each other from the portion (first merge portion) where the flow channels of the spray fluid 2 and the spray medium 3 merge in the above-described flow channel configuration. Bending

portions

13 and 14 are provided in the mixed

fluid flow passages

9 and 10 between the outlet holes 11 in the portion (second confluence portion) where the mixed fluid 8 flowing through the

fluid flow passages

9 and 10 joins.

The flow direction of the mixed fluid 8 is changed by providing the mixed

fluid flow paths

9 and 10 with the

bent portions

13 and 14. Therefore, the flow of the mixed

fluid flow paths

9 and 10 is disturbed, and mixing of the spray fluid 2 and the spray medium 3 constituting the mixed fluid 8 proceeds.

By mixing the two uniformly, the ratio of the atomizing medium 3 in the mixed fluid 8 becomes uniform, and the atomization progresses uniformly. Therefore, the amount of the atomizing medium 3 necessary for promoting atomization can be suppressed. Even if the pressure applied to the spray fluid 2 or the spray medium 3 is reduced, atomization can be maintained.

It should be noted that the change angle of the flow direction at the

bent portions

13 and 14 is desirably about 30 to 120 degrees in order to cause disturbance. That is, when the change angle is 30 degrees or less, the change in the flow direction is small, so there is little turbulence and mixing is hardly promoted. When the change angle is 120 degrees or more, the pressure loss due to the change in flow increases.

FIG. 5 shows an example of atomization performance of the spray nozzle 1 according to the present embodiment. In the figure, the left vertical axis represents the average particle diameter of the spray, the right vertical axis represents the pressure loss ratio, and the horizontal axis represents the change angle of the flow direction at the

bent portions

13 and 14. Pressure loss was based on a change angle of 90 degrees.

The average particle size of the spray is determined by optical measurement of the sprayed particle size in the long side direction and the short side direction passing through the central axis of the fan type spray at a position 300 mm downstream of the spray for the fan type spray ejected from the outlet hole 11. It is measured and the average value is shown by the body area average particle diameter.

As shown in FIG. 5, when the change angle of the flow direction at the

bent portions

13 and 14 is as narrow as 20 degrees, the average particle diameter of the spray is about 10 μm larger than the change angle is 30 degrees. This is because when the

bent portions

13 and 14 are at a small angle, the change in the flow direction is small, so that there is little turbulence and it is difficult to promote mixing. On the other hand, at an angle of 120 degrees or more, the pressure loss due to the flow change becomes large.

For this reason, it can be seen that the change angle for causing the disturbance of the flow direction at the

bent portions

13 and 14 is desirably 30 degrees or more and 120 degrees.

Further, the mixing part of the spray fluid flow paths 4 and 5 of the spray fluid 2 and the spray medium 3 and the spray medium flow paths 6 and 7 promotes the mixing of the both, so that the crossing angle is 30 to 90 degrees. It is desirable to merge. That is, when the angle is less than 30 degrees, the change in the flow direction is small, and both flow in parallel, so that mixing is difficult to be promoted. Because.

In the spray nozzle 1 of the present embodiment, the surface area per unit weight of the liquid fuel increases due to atomization, so that the combustion reaction proceeds, the unburned matter, soot and carbon monoxide at the outlet of the combustion device are reduced, and the combustion efficiency is improved. Can be high. Moreover, by accelerating the combustion reaction, consumption of oxygen progresses and generation of nitrogen oxides can be suppressed. In addition, the amount of unburned dust, soot, and carbon monoxide can be reduced, so that excess air introduced into the combustion apparatus can be reduced. Moreover, when excess air reduces, the amount of combustion exhaust gas will also fall, the sensible heat discharge | released out of a combustion apparatus with combustion exhaust gas will be reduced, and thermal efficiency can be improved.

抑制 By controlling the amount of spray medium used and reducing the pressure, the energy consumption required for each supply and pressurization can be reduced. In addition, when steam is used as the spraying medium, the thermal efficiency of the combustion apparatus due to the steam introduced into the combustion apparatus is reduced, but if the spray nozzle 1 of this embodiment is used, even if the amount of steam used is reduced, Since atomization can be maintained at the same level as in the past, it is possible to prevent a decrease in thermal efficiency.

Further, in the present embodiment, the case where liquid fuel is used as the combustion device is shown, but it is also applicable to the case where solid fuel such as pulverized coal is used as the main fuel and liquid fuel is used as the auxiliary fuel. In this case, when the liquid fuel is sprayed from the spray nozzle 1 into the furnace 31, the above-described effect can be obtained.

Further, in this embodiment, as shown in FIG. 2, the combustion air is branched into

pipes

45 and 46 and injected into the furnace 31 from the burner 20 and the air supply port 44, respectively. Thus, the temperature of the flame formed with the burner 20 can be reduced by supplying combustion air separately.

Further, when combustion is performed in the vicinity of the burner 20 in an air-deficient state, a part of nitrogen contained in the fuel is generated as a reducing agent, and a reaction occurs in which NOx generated by the combustion is reduced to nitrogen.

Therefore, the NOx concentration at the outlet of the furnace 31 is reduced as compared with the case where all the combustion air is supplied from the burner 20. Further, by supplying the remaining combustion air from the air supply port 44 and completely burning the fuel, the amount of unburned fuel can be reduced.

Also, the combustion gas 47 mixed with the combustion air from the air supply port 44 passes through the flue 49 via the heat exchanger 48 at the top of the furnace 31 and is discharged from the chimney 50 to the atmosphere.

In the example of the combustion apparatus shown in FIG. 2, the example in which the combustion air is branched into the

pipes

45 and 46 is shown, but the spray nozzle of the present embodiment is also used when the combustion air is not branched and is supplied only from the burner 20. 1 can be applied. Moreover, although the case where the burner 20 is provided on one wall surface of the furnace 31 is shown in FIGS. 1 and 2, the present invention can be applied to the case where the burner 20 is provided on a plurality of wall surfaces or the corner portion of the wall surface.

Like the spray nozzle of the present embodiment, the flow direction of the mixed fluid changes by providing a bent portion between the flow path of the mixed fluid in which the spray fluid and the spray medium are mixed. The flow of the mixed fluid flowing through the flow path is disturbed, and mixing of the spray fluid and the spray medium proceeds. In addition, when both are uniformly mixed, the ratio of the spray medium in the mixed fluid becomes uniform, and the atomization progresses uniformly.

For this reason, it is possible to suppress the amount of the spray medium used for promoting atomization and to maintain the atomization even if the pressure applied to the spray fluid or the spray medium is reduced.

6 and 7 show a second embodiment of the spray nozzle of the present invention. The present embodiment shown in the figure has a plurality of outlet holes in the spray nozzle 1 and a plurality of second merging portions where the mixed fluids flowing through the mixed fluid flow passages formed opposite to each other join each other. Between the first and second merging portions where the flow paths of the spraying medium and the merging medium merge, there are communication channels that connect the plurality of second merging portions.

That is, the difference between the present embodiment and the first embodiment is that the spray nozzle 1 has a plurality of

outlet holes

11A and 11B and the flow path structure on the upstream side of the outlet holes 11A and 11B. Here, the description will focus on the portion related to the channel structure.

Note that FIG. 6 shows a case where there are two upper and lower outlet holes, which are distinguished by subscripts A and B, respectively, but the configuration is the same when more outlet holes are provided.

6 and 7, the spray fluid 2 and the spray medium 3 are separated from the spray

fluid flow paths

4A, 4B, 5A, and 5B and the spray medium flow path 6A, respectively. It passes through 6B, 7A and 7B and is mixed at the first junction through the

bent portions

13A, 13B, 14A and 14B. The mixed fluid 8 of the spray fluid 2 and the spray medium 3 passes through the mixed

fluid flow paths

9A, 9B, 10A, and 10B that flow in opposition to each other, in the vicinity of the outlet holes 11A and 11B that are the second merging portions. Colliding and ejecting from the

respective outlet holes

11A and 11B.

The mixed fluid 8 ejected from the outlet holes 11A and 11B forms a fan-shaped spray in a direction perpendicular to the flow direction of the

mixed fluid channels

9A, 9B, 10A, and 10B (the direction in which the mixed fluid channel extends) by collision. To do.

Grooves

12A and 12B are formed in the outlet holes 11A and 11B of the spray nozzle 1 in the same direction as the fan spray formation direction, and the

grooves

12A and 12B intersect the mixed

fluid flow paths

9A, 9B, 10A and 10B. The parts become

outlet holes

11A and 11B.

In the present embodiment, the mixed

fluid flow paths

10A and 10B in the central part are connected to the outlet holes 11A and 11B by a connecting pipe (connecting flow path) 60 that connects the two to each other. Further, the mixed

fluid flow paths

9A and 9B on the outer peripheral side are connected to the outlet holes 11A and 11B by branch pipes (communication flow paths) 61 (see FIG. 7) that connect the two to each other.

The atomizing fluid 2 is atomized by mixing with the atomizing medium 3 and, of course, a thin liquid film is formed by the collision of the mixed fluid 8 at the outlet holes 11A and 11B, and after being ejected from the outlet holes 11A and 11B, The liquid film is split and atomized by the shearing force. The liquid film is atomized by the collision force of the fluid, and the mixed

fluid flow paths

9 and 10 have the

bent portions

13 and 14 as in the first embodiment, so that the spray fluid 2 and the spray medium 3 can be mixed. Promoted and atomized.

By increasing the number of outlet holes of the spray nozzle 1, so-called perforation, the amount of spray from the spray nozzle 1 can be increased without increasing the amount of spray from one outlet hole. The problem of increasing the volume of the spray nozzle 1 is that the atomization performance is deteriorated when the outlet hole is partially blocked and the flow path is blocked.

In the spray nozzle 1 of the present embodiment, when a part of the outlet holes 11A and 11B is blocked by impurities or deposits in the spray fluid 2 or the spray medium 3, or when part of the outlet holes 11A and 11B is blocked, mixing that leads to the corresponding outlet hole In the flow path of the fluid 8, the fluid flows through the flow paths of the mixed fluid 8, the spray fluid 2, and the spray medium 3 through the branch pipe 61 toward the other outlet holes that are opened. Thus, the temperature is maintained.

For example, when the outlet hole 11A is blocked for some reason, the flow stops at a portion near the outlet hole 11A in the mixed fluid flow path 9A connected to the outlet hole 11A or the mixed fluid flow path 10A after branching.

However, the mixed fluid 8 flows to the outlet hole 11B through the branch pipe 61 in the upstream side of the mixed fluid channel 9A and the spray fluid channel 4A and the spray medium channel 6A. Further, in the mixed fluid flow path 10A, the spray fluid flow path 5A and the spray medium flow path 7A upstream thereof, the fluid flows through the connecting pipe 60 to the outlet hole 11B.

For this reason, since the mixed fluid 8 flows into the outlet hole 11B from a large number of flow paths, the resistance in the flow path is reduced and the flow rate is increased. Can be suppressed.

When the liquid fuel flowing as the atomizing fluid 2 is heated, the solid content is precipitated, and this solid content may cause the blockage of the flow path. However, in the spray nozzle 1 of this embodiment, the branch pipe is used. Since the flow can be maintained toward the outlet hole that is opened through 61, the blockage hardly progresses.

That is, even if a part of the outlet hole is blocked, the blocked portion remains from the outlet hole to the branch pipe 61 and can be easily removed. For example, when the above-described outlet hole 11A is blocked, the blocked portion remains in a portion near the outlet hole 11A in the mixed

fluid flow paths

9A and 10A.

Furthermore, in the spray nozzle 1 of the present embodiment, the spray fluid 2 and the spray medium 3 are individually mixed in the mixing section in the middle of the flow path, and the ratio of the spray medium 3 to the mixed fluid 8 can be maintained. For this reason, the atomization characteristic of the mixed fluid 8 ejected from each outlet hole can be maintained constant.

Thus, in this embodiment, even when some of the outlet holes are blocked, the atomization characteristics of the mixed fluid 8 ejected from the normal outlet holes can be maintained constant. Moreover, since the blockage | closure of a flow path remains in a part, the fall of the ejection amount of the spray fluid 2 from the spray nozzle 1 can be suppressed.

For this reason, since the atomization of the mixed fluid 8 can be maintained, the amount of the spray medium 3 used can be suppressed. Moreover, also when raising the pressurizing force of the spray fluid 2 or the spraying medium 3 in order to supplement the ejection amount, the increase in the pressurizing force can be suppressed.

As described above, the atomization of the mixed fluid 8 increases the surface area per unit weight of the liquid fuel, so that the combustion reaction proceeds, reducing unburned matter, soot and carbon monoxide at the combustion device outlet, and improving the combustion efficiency. Can be high. Moreover, by accelerating the combustion reaction, consumption of oxygen progresses and generation of nitrogen oxides can be suppressed.

Furthermore, by reducing the amount of unburned matter, dust, and carbon monoxide, it is possible to reduce excess air that is input to the combustion device. When excess air is reduced, the amount of combustion exhaust gas is also reduced, and the sensible heat released to the outside of the combustion apparatus together with the combustion exhaust gas is reduced, so that the thermal efficiency can be increased.

Also, by suppressing the amount of spray medium 2 used and reducing the pressure, the energy consumption used for each supply and pressurization can be reduced. Further, when steam is used as the spray medium 2, the thermal efficiency of the combustion apparatus due to the steam introduced into the combustion apparatus is lowered. However, if the spray nozzle 1 of this embodiment is used, the amount of steam used can be reduced. In addition, since the atomization of the mixed fluid 8 can be maintained at the same level as in the past, it is possible to prevent a decrease in thermal efficiency.

8 to 10 show a third embodiment of the spray nozzle of the present invention. In the present embodiment shown in the figure, the spray nozzle 1 has a plurality of outlet holes, and the mixed fluid flow path branches into a plurality downstream of the first joining portion where the flow paths of the spray fluid and the spray medium merge. The branched mixed fluid channel forms a channel connected to each of the different outlet holes.

That is, the difference between the present embodiment and the second embodiment is the flow path structure on the upstream side of the outlet holes 11A and 11B. Here, the description will focus on the portion related to the channel structure. 8 to 10 show the case where the upper and

lower outlet holes

11A and 11B are provided, the configuration is the same when a larger number of outlet holes are provided.

In the tip of the spray nozzle 1 of the present embodiment shown in FIG. 9, the spray fluid 2 and the spray medium 3 pass through the independent

spray fluid channels

4A and 4B and the

spray medium channels

6A and 6B, and the first Mixed at the junction. The mixed fluid 8 of the spray fluid 2 and the spray medium 3 passes through the mixed

fluid flow paths

9A and 9B.
The mixed

fluid flow paths

9A and 9B are branched in the middle, and further branched into annular mixed

fluid flow paths

9C, 9D, 9E, and 9F shown by dotted lines in FIG. 8, and mixed fluids toward the outlet holes 11A and 11B, respectively. 8 flows.

The outlet holes 11A and 11B of the spray nozzle 1 in this embodiment are provided concentrically with respect to the central axis of the spray nozzle 1, and the first through the branched mixed

fluid flow paths

9C, 9D, 9E, and 9F. The flow path to the 2 junctions is formed circumferentially with respect to the central axis of the spray nozzle 1.

Then, the mixed fluid 8 collides in the vicinity of the outlet holes 11A and 11B, which are the second merging portions, and is ejected from the outlet holes 11A and 11B. The mixed fluid 8 ejected from the outlet holes 11A and 11B forms a fan-shaped spray in a direction perpendicular to the flow direction (circumferential direction in FIG. 8) of the mixed

fluid flow paths

9C, 9D, 9E, and 9F by collision. .

For this reason, in this embodiment, spray is formed in the radial direction with respect to the central axis of the spray nozzle 1.

Grooves

12A and 12B are formed in the outlet holes 11A and 11B of the spray nozzle 1 in the same direction (radial direction) as the fan-shaped spray formation direction, and the intersections between the

grooves

12A and 12B and the mixed fluid flow path are outlets. It becomes

hole

11A, 11B.

The atomizing fluid 2 is atomized by mixing with the atomizing medium 3 and becomes a thin liquid film due to the collision of the mixed fluid 8 at the outlet holes 11A and 11B, and is ejected from the outlet holes 11A and 11B by the shearing force with the surrounding gas. The liquid film breaks up and atomizes.

In this way, the liquid film is atomized by the collision force of the fluid, and as shown in the first and second embodiments, the mixed fluid flow path has the

bent portions

13 and 14, so that the spray fluid 2 and the spray medium 3 are used. Is promoted and atomization proceeds.

Further, in the spray nozzle 1 of the present embodiment, as shown in the second embodiment, when a part of the outlet hole is blocked by the impurities or deposits in the spray fluid 2 or the spray medium 3, or partially blocked, In the flow path of the mixed fluid 8 connected to the corresponding outlet hole, the fluid flows through the branch pipe 61 and the flow path of the mixed fluid 8, the spray fluid 2, and the spray medium 3 toward the other opened outlet holes. Each channel is maintained at a temperature by a fluid.

When the liquid fuel flowing as the spray fluid 2 is heated, precipitation of solids occurs, and this precipitation of solids may cause clogging of the flow path. In the spray nozzle 1 of this embodiment, the branch pipe 61 is provided. After that, since the flow can be maintained toward the outlet hole that is open, the blockage hardly progresses.

That is, even if a part of the outlet hole is blocked, the blocked portion remains from the outlet hole to the branch pipe 61 and can be easily removed. For example, when the above-described outlet hole 11A is blocked, the blocked portion remains in the mixed

fluid flow paths

9C and 9E close to the outlet hole 11A in the mixed fluid flow path 9A.

Furthermore, in the spray nozzle 1 of the present embodiment, the spray fluid 2 and the spray medium 3 are individually mixed in the mixing part in the middle of the flow path, and the ratio of the spray medium 3 to the mixed fluid 8 can be maintained. The atomization characteristics of the mixed fluid 8 ejected from the individual outlet holes can be maintained constant.

As described above, in this embodiment as well as in Embodiment 2, even when some of the outlet holes are blocked, the atomization characteristics of the mixed fluid ejected from the normal outlet holes can be maintained constant. Moreover, since the blockage | closure of a flow path remains in a part, the fall of the ejection amount of the spray fluid 2 from the spray nozzle 1 can be suppressed.

Therefore, since the atomization of the mixed fluid 8 can be maintained, the amount of the spray medium 3 used can be suppressed. Moreover, also when raising the pressurizing force of the spray fluid 2 or the spraying medium 3 in order to supplement the ejection amount, the increase in the pressurizing force can be suppressed.

Further, in the above-described Examples 2 and 3, the case where there are two outlet holes is shown as an example, but the effect is also as described above when a large number of outlet holes are provided. Furthermore, when the spray nozzle 1 is incorporated in the combustion apparatus, the effects of promoting atomization, reducing the spray medium, and reducing the applied pressure can be obtained, as in the first embodiment.

Further, as the combustion apparatus of the above-described embodiment, the one that burns solid fuel and liquid fuel has been described, but it is needless to say that it can be applied to a combustion apparatus that burns fossil fuel instead of solid fuel and liquid fuel. .

In addition, this invention is not limited to the above-mentioned Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 1 ... Spray nozzle, 2 ... Spray fluid, 3 ...

Spray medium

4, 4A, 4B, 5, 5A, 5B ... Spray fluid flow path, 6, 6A, 6B, 7, 7A, 7B ... Spray medium flow path , 8 ... Mixed fluid, 9, 9A, 9B, 9C, 9D, 9E, 9F, 10, 10A, 10B ... Mixed fluid flow path, 11, 11A, 11B ... Outlet hole, 12, 12A, 12B ... Groove, 13, 13A, 13B, 14, 14A, 14B ... bent portion, 20 ... burner, 21 ... central axis, 22 ... obstacle, 23 ... spray, 24 ... wind box, 25 ... primary flow path, 26 ... secondary flow path, 27 ... tertiary flow path, 28 ... primary air, 29 ... secondary air, 30 ... tertiary air, 31 ... furnace, 32, 33 ... swirl flow generator, 34 ... guide plate, 35 ... furnace wall, 36 ... Heat transfer tube, 41 ... Combustion air supply system, 42 ... Liquid fuel supply system, 43 ... Spraying medium supply System, 44 ...

air supply port

45, 46 ... pipe, 47 ... combustion gas, 48 ... heat exchanger, 49 ... flue, 50 ... chimney, 60 ... connecting tube, 61 ... branch pipe.

Claims

At least two spray fluid flow paths through which the spray fluid flows, at least two spray medium flow paths through which the spray medium flows, and merge at the respective spray fluid flow paths and the first merging portion, and the respective first. The mixed fluid of the sprayed fluid and the spraying medium joined at the joining portion of the fluid flows, and is formed so as to face each other. A fluid flow path, and an outlet hole for ejecting the mixed fluid joined at the second joining portion,
The spray nozzle, wherein the mixed fluid flow path is formed with a bent portion that changes a flow direction of the mixed fluid between the first joining portion and the second joining portion.
A spray nozzle for mixing and atomizing a spray fluid with a spray medium, and having a spray fluid flow path and a spray medium flow path at an inlet of the spray nozzle, the spray fluid flow path and the spray medium flow path being The spray nozzle has a first merge section where the flow paths merge with each other, and the spray nozzle has a plurality of mixed fluid flow paths in which the spray fluid and the spray medium merge, and the mixed fluid flow A part of the path has a second merging portion where the mixed fluid flows opposite to each other, and a flow opposed to each other at the outlet portion of the spray nozzle collides and merges, and immediately after the second merging portion With an exit hole,
The spray nozzle, wherein the mixed fluid flow path is formed with a bent portion that changes a flow direction of the mixed fluid between the first joining portion and the second joining portion.
The spray nozzle according to claim 1 or 2,
The bent portion formed in the mixed fluid flow path between the first merging portion and the second merging portion has a change angle of 30 to 120 degrees in the flow direction of the mixed fluid. Spray nozzle to do.
The spray nozzle according to any one of claims 1 to 3,
The spray nozzle has a plurality of outlet holes, a plurality of the second merging portions, and the plurality of second merging portions are connected between the first merging portion and the second merging portion. A spray nozzle characterized by having a connecting flow path.
The spray nozzle according to claim 4.
The communication channel includes two communication fluid channels positioned at the center of the spray nozzle, a communication tube that connects the two to each other in the middle of the outlet hole, and two channels positioned on the outer peripheral side of the spray nozzle. A spray nozzle, wherein the mixed fluid flow path comprises a branch pipe that connects the two to each other in the middle of the outlet hole.
The spray nozzle according to any one of claims 1 to 3,
The spray nozzle has a plurality of outlet holes, the mixed fluid flow path is branched into a plurality of downstreams of the first portion, and the branched mixed fluid flow paths are connected to the different outlet holes, respectively. A spray nozzle characterized by forming a flow path.
The spray nozzle according to claim 6.
The outlet hole of the spray nozzle is provided concentrically with respect to the central axis of the spray nozzle, and the flow path from the branched mixed fluid flow path to the second junction is the center of the spray nozzle. A spray nozzle characterized in that it is formed circumferentially with respect to an axis.
The spray nozzle according to any one of claims 1 to 7,
A spray nozzle characterized in that a groove is formed in the outlet hole of the spray nozzle in the same direction as the spray formation direction from the spray nozzle.
The spray nozzle according to claim 8,
The spray nozzle, wherein an intersection of the groove and the mixed fluid flow path is the outlet hole.
A burner that uses liquid fuel as fuel,
The spray nozzle according to any one of claims 1 to 9, wherein the liquid fuel is supplied to the tip of the spray nozzle as the spray fluid, and steam or compressed air is used as the spray medium for the spray nozzle. A burner that is supplied to the tip.
A burner having a fuel nozzle for ejecting a solid fuel and a carrier gas thereof, a spray nozzle for spraying a liquid fuel, and a combustion gas nozzle for ejecting a combustion gas for burning the solid fuel and the liquid fuel;
The spray nozzle according to any one of claims 1 to 9 is used as the spray nozzle, the liquid fuel is supplied to the tip of the spray nozzle as the spray fluid, and steam or compressed air is supplied to the spray medium. The burner is supplied to the tip of the spray nozzle as follows.
A combustion device for burning solid fuel and liquid fuel,
A combustion furnace that burns fuel; a solid fuel supply system that supplies solid fuel to the combustion furnace; a liquid fuel supply system that supplies liquid fuel to the combustion furnace; and a combustion gas that supplies combustion gas to the combustion furnace A gas supply system, a plurality of burners connected to the fuel supply system and the combustion gas supply system to burn the solid fuel or liquid fuel provided on the furnace wall of the combustion furnace, and combustion generated in the combustion furnace A heat exchanger for recovering heat from the exhaust gas, and a flue for supplying the heat recovered combustion exhaust gas to the outside of the combustion furnace,
A combustion apparatus using the burner according to claim 10 or 11 as one of the burners.
A combustion device for burning fossil fuel,
A combustion furnace for burning fossil fuel, a fuel supply system for supplying fossil fuel to the combustion furnace, a combustion gas supply system for supplying combustion gas to the combustion furnace, the fuel supply system, and the combustion gas supply A burner that is connected to the system and burns fossil fuel provided on the furnace wall of the combustion furnace, a heat exchanger that recovers heat from the combustion exhaust gas generated in the combustion furnace, and the combustion exhaust gas that is recovered from the heat A flue that supplies to the outside of the
A combustion apparatus using the burner according to claim 10, wherein a liquid fuel is used as the fossil fuel.