JP2013160470A - Spray nozzle and combustion device with spray nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spray nozzle for collecting file particles near the spray nozzle to accelerate ignition, raising momentum of spraying to accelerate a mixture of spraying particles with air for combustion, and reducing an amount of emission of dust.SOLUTION: In a spray nozzle in which a pressure is applied to a liquid fuel as a spraying fluid for spraying and a pressure is applied to another fluid as a medium for spraying so as to mix it with the spraying fluid for ejection, a tip end of the spray nozzle is equipped with a plurality of ejection holes for ejecting the spraying fluid, an spraying fluid passage for flowing down the spraying fluid via a plurality of ejection holes on one side so as to eject only the spraying fluid and communicating with the spraying holes on the one side is internally arranged at the tip end of the spray nozzle. In addition, the tip end of the spray nozzle is equipped with another spraying fluid passage for flowing down the spraying fluid so as to eject a mixed fluid of the spraying fluid and the medium via a plurality of ejection holes on the other side, a medium passage for spraying for flowing down a spraying medium, and a converged flow path of the spraying fluid passage and medium passage for spraying, and the converged flow path is communicated with the ejection holes on the other side.

Description

  The present invention relates to a spray nozzle for atomizing liquid fuel and a combustion apparatus including the spray nozzle.

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

  Such spray nozzles are used for combustion of auxiliary fuel for start-up and flame stabilization, in addition to combustion devices that use liquid fuel as the main fuel, as well as combustion devices that use solid fuel as the main fuel, such as pulverized coal. It is often done.

  In the combustion of liquid fuel, if the spray particle size is large, the combustion reaction is delayed, and the combustion efficiency is reduced, soot and carbon monoxide are likely to be generated. Further, even when the spray particle size is small, mixing with the combustion air is poor, 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, attention is paid to mixing of spray particles and combustion air together with atomization.

  In general, the following two methods are used as the form of the spray nozzle. One of them is a pressure spray system in which liquid fuel (atomizing fluid) is usually pressurized to 0.5 to 5 MPa and the pressure is used for atomization. An example of this type of spray nozzle is disclosed in Japanese Patent Laid-Open No. 2004-92952 (Patent Document 1). The other is a two-fluid spray system in which air or steam is supplied as a spray medium for atomization and mixed with the spray fluid to atomize. An example of this type of spray nozzle is disclosed in Japanese Patent Application Laid-Open No. 2010-127518 (Patent Document 2) and Japanese Patent Application Laid-Open No. 8-61609 (Patent Document 3), respectively. Patent Documents 2 and 3 describe examples of nozzles that have a plurality of ejection holes in one spray nozzle and form sprays that are independent from the individual ejection holes.

JP 2004-92952 A JP 2010-127518 A JP-A-8-61609

When a liquid fuel is sprayed and burned, an electric spark type igniter is recently used as an initial ignition source. Although this igniter requires a circuit for generating an electric spark to the outside, it can be configured with a simple mechanism by simply inserting an igniter rod for generating a spark into the combustion chamber. At this time, if the igniter rod is provided on the spray nozzle side, it can be handled in combination with the spray nozzle, and the operability is improved. Further, the shorter the distance from the spray nozzle, the shorter the length of the igniter rod exposed in the combustion chamber, which is desirable in terms of durability.

  In order to ignite liquid fuel using an igniter, it is desirable to retain a large amount of fine particles in the vicinity of the igniter or the spray nozzle. By retaining the fine particles, the fine particles can be evaporated and burned with an electric spark with less energy than the large particles. Once the particulates start to burn, the combustion heat ignites the nearby particles, spreading the flame and forming a liquid fuel flame.

  The above-mentioned prior art documents 2 and 3 both relate to a two-fluid spray nozzle that joins liquid fuel and a spray medium in the middle of an ejection hole and sprays the mixed fluid. In this spray nozzle, the flow velocity ejected from the ejection hole is fast, and the momentum of spray is large. For this reason, the arrival position of the spray is long. Moreover, since the momentum is large, the surrounding air is engulfed and burned, and the amount of dust generation is small.

  However, since the formation of fine particles is small and the fine particles have a large momentum of spraying, they move to a position away from the vicinity of the spray nozzle.

  Further, in the two-fluid spray nozzle, it is necessary to increase the amount of the spray medium in order to increase the fine particles. When the amount of the spray medium is increased, the spray amount of the spray fluid decreases due to the pressure, and the combustion amount decreases. Further, when the amount of the spray medium is increased, the energy efficiency is lowered.

  On the other hand, in the pressure spray type spray nozzle of Prior Art Document 1, a liquid film is formed by a swirling flow and is atomized by a shearing force with the surrounding gas. For this reason, the momentum of the spray is smaller than that of the two-fluid spray nozzle.

  However, if the spread angle of the spray is large and a plurality of spray holes are provided, the combustion performance may be deteriorated, for example, the individual sprays interfere with each other and dust is easily generated.

  For this reason, in the above-described conventional technology, it is difficult to achieve both the acceleration of ignition by collecting fine particles in the vicinity of the spray nozzle and the promotion of the mixing of the spray particles and the combustion air by increasing the momentum of the spray. There was a problem.

  The object of the present invention is to collect the fine particles in the vicinity of the spray nozzle to promote ignition and to increase the momentum of the spray to promote the mixing of the spray particles and the combustion air to reduce the generation amount of dust. The object is to provide a good spray nozzle and a combustion device having this spray nozzle.

  The spray nozzle of the present invention is a spray nozzle in which liquid fuel is sprayed by applying a pressure as a spray fluid, and another fluid is sprayed by being mixed with the spray fluid by applying pressure as a spray medium, and the tip of the spray nozzle A plurality of spray holes for spraying the spray fluid, and a spray fluid flow path for allowing the spray fluid to flow down and communicating with the one spray hole so that only the spray fluid is ejected from one of the plurality of spray holes A spray fluid flow path for allowing the spray fluid to flow down so that a mixed fluid of the spray fluid and the spray medium is ejected from the other ejection holes provided in the plurality of the spray nozzles. A spraying medium flow path for causing the spraying medium to flow down, and a merged flow path in which the spray fluid flow path and the spraying medium flow path are joined to each other inside the tip portion of the spray nozzle, and the merged flow path This Characterized in that communicated in a square injection ports.

  The spray nozzle of the present invention is a spray nozzle that applies pressure as a spray fluid to spray liquid fuel and mixes and sprays another fluid as a spray medium by applying pressure. A plurality of spray holes for spraying the spray fluid at the tip, a plurality of spray fluid flow paths for allowing the spray fluid to flow down so that only the spray fluid is ejected from one of the plurality of spray holes, and a plurality of these A joint flow path through which the spray fluid flowing through the spray fluid flow path faces is provided inside the tip of the spray nozzle, and the joint flow path is communicated with the one ejection hole in the joint flow path. Another spray fluid flow path for causing the spray fluid to flow down so that the spray fluid that intersects is ejected from the one ejection hole and the mixed fluid of the spray fluid and the spray medium is ejected from the other ejection hole provided in plural When A spraying medium flow path for causing the spraying medium to flow down, and a merged flow path in which the spray fluid flow path and the spraying medium flow path are joined to each other inside the tip portion of the spray nozzle, and the merged flow path Is communicated with the other ejection hole so that the mixed fluid of the spray fluid and the spray medium is ejected from the other ejection hole.

  The spray nozzle of the present invention is a spray nozzle that applies pressure as a spray fluid to spray liquid fuel and mixes and sprays another fluid as a spray medium by applying pressure. A plurality of spray fluids that flow down the spray fluid so that the spray fluid and the spray medium are mixed and ejected from one of the plurality of spray holes provided at the tip portion. A flow path, a plurality of spray medium flow paths for causing the spray medium to flow down, and a combined flow path through which the spray fluid flowing through the plurality of spray fluid flow paths face each other are provided inside the tip of the spray nozzle. A plurality of spraying medium flow paths are connected to the combined flow path, the combined flow path is communicated with the one ejection hole, and another spray fluid is separated from the other plurality of ejection holes. Mixing spray media Another spray fluid flow path for causing the spray fluid to flow down, another spray medium flow path for causing the spray medium to flow down, the spray fluid flow path and the spray medium flow path, Are provided inside the tip of the spray nozzle, and the combined flow channel is communicated with the other ejection hole so that the mixed fluid of the spray fluid and the spray medium is discharged from the other ejection hole. It is configured to be ejected.

  Further, the spray nozzle of the present invention is a spray nozzle that sprays liquid fuel as a spray fluid and applies pressure, and sprays another fluid as a spray medium and applies pressure and mixes with the spray fluid, and the tip of the spray nozzle A first spray fluid flow for causing the spray fluid to flow down so that a mixed fluid of the spray fluid and the spray medium is ejected from one of the plurality of spray holes, A spray passage, a spray medium flow path for allowing the spray medium to flow down, and a merge flow path in which the spray fluid flow path and the spray medium flow path are joined to each other inside the tip of the spray nozzle, and The combined flow path is communicated with the one ejection hole, and the mixed fluid of the spray fluid and the spray medium is ejected from the one ejection hole, and another spray fluid and another spray are ejected from the other plurality of ejection holes. Mixed media , A second spray fluid flow path that causes the other spray fluid to flow down, a second spray medium flow path that causes the other spray medium to flow down, the spray fluid flow path and the spray. Second merging channels that merge with the medium flow channel are provided inside the tip of the spray nozzle, respectively, and the second merging channel is communicated with the other ejection holes, The mixed fluid of the spray medium is ejected from the other ejection hole, and the area of the first spray fluid channel is formed smaller than the area of the second spray fluid channel. .

  Further, the spray nozzle of the present invention is a spray nozzle that sprays liquid fuel as a spray fluid and applies pressure, and sprays another fluid as a spray medium and applies pressure and mixes with the spray fluid, and the tip of the spray nozzle A first spray fluid flow for causing the spray fluid to flow down so that a mixed fluid of the spray fluid and the spray medium is ejected from one of the plurality of spray holes, A spray passage, a spray medium flow path for allowing the spray medium to flow down, and a merge flow path in which the spray fluid flow path and the spray medium flow path are joined to each other inside the tip of the spray nozzle, and The combined flow path is communicated with the one ejection hole, and the mixed fluid of the spray fluid and the spray medium is ejected from the one ejection hole, and another spray fluid and another spray are ejected from the other plurality of ejection holes. Mixed media A second spray fluid flow path for causing the other spray fluid to flow down, a second spray medium flow path for causing the spray medium to flow down, and the spray fluid flow path and the spray medium. A second merging channel that merges with the channel is provided inside the tip of the spray nozzle, and the second merging channel is communicated with the other ejection hole so that the spray fluid and the spray medium The mixed fluid is ejected from the other ejection hole, and further flows down the spraying medium flow path with respect to the flow rate of the spray fluid flowing down the first spray fluid flow path ejected as the mixed fluid from the one ejection hole. The flow rate of another spraying medium relative to the flow rate of another spraying fluid flowing down the second spraying fluid flow channel ejected as a mixed fluid from the other ejection hole is larger than the ratio of the flow rate of the spraying media The ratio of the flow rate of the different spraying media flowing down Characterized by being configured such increases.

  A combustion apparatus having a spray nozzle according to the present invention includes a combustion furnace for burning fuel, a fuel supply system for supplying fuel and a carrier gas for transporting the fuel to the combustion furnace, and supplying a combustion gas to the combustion furnace. A combustion gas supply system, a burner to which the fuel supply system and the combustion gas supply system are connected to burn the fuel provided on the furnace wall of the combustion furnace, and the burner provided to the combustion furnace A combustion apparatus comprising: a heat exchanger for exchanging heat from combustion exhaust gas generated by combustion; and a flue for causing combustion exhaust gas after heat exchange with the heat exchanger of the combustion furnace to flow down to the outside of the combustion furnace In this case, any one of the above-described spray nozzles using liquid fuel as at least a part of the fuel is used as the spray nozzle used in the combustion apparatus.

  According to the present invention, fine particles are collected in the vicinity of the spray nozzle to promote ignition, and the momentum of the spray is increased to promote the mixing of the spray particles and the combustion air to reduce the generation amount of dust. It is possible to realize a good spray nozzle and a combustion apparatus having this spray nozzle.

The schematic block diagram which showed an example of the combustion apparatus provided with the spray nozzle which is the Example of this invention. The fragmentary sectional view which shows the structure of the front-end | tip part of the spray nozzle which concerns on 1st Example of this invention. The schematic block diagram which showed the burner using the spray nozzle which concerns on 1st Example of this invention. The partial view which looked at the spray nozzle vicinity of the burner which concerns on 1st Example of this invention from the furnace of the combustion apparatus. The fragmentary sectional view which shows the structure of the front-end | tip part of the spray nozzle which concerns on 2nd Example of this invention. The fragmentary sectional view which shows the structure of the front-end | tip part of the spray nozzle which concerns on the modification of 2nd Example of this invention. The fragmentary sectional view which shows the structure of the front-end | tip part of the spray nozzle which concerns on 3rd Example of this invention.

  A spray nozzle and a combustion apparatus equipped with this spray nozzle according to an embodiment of the present invention will be described with reference to the drawings.

  An example of the combustion apparatus provided with the spray nozzle which is the Example of this invention is shown in FIG. In the boiler of the combustion apparatus having the spray nozzle according to the embodiment of the present invention shown in FIG. 1, a plurality of burners 2 for supplying fuel and combustion air are installed on the wall surface of the furnace 1 constituting the boiler. Has been. The burner 2 is provided with a combustion air supply system 3 for supplying combustion air, a liquid fuel supply system 4 for supplying liquid combustion, and a spraying medium supply system 5 for supplying a spraying medium.

  In the boiler of the present embodiment, the combustion air supply system 3 includes a pipe 6 connected to the burner 2 installed on the wall surface of the furnace 1, and air installed at a position downstream of the burner 2 on the wall surface of the furnace 1. It branches into the piping 7 connected to the supply port 8, and is connected to the said burner 2 and the said air supply port 8, respectively.

  The pipes 6 and 7 are provided with flow rate control valves (not shown) for adjusting the flow rate of combustion air supplied to the burner 2 and the flow rate of air supplied to the air supply port 8, respectively.

  The liquid fuel supply system 4 and the spray medium supply system 5 are each provided with a feeder (not shown) for adjusting the pressure and flow rate of the liquid fuel and the spray medium on the upstream side. A spray nozzle 9 is installed at the downstream end.

  In the boiler of the present embodiment, the combustion air supplied through the combustion air supply system 3 is branched into pipes 6 and 7 and ejected into the furnace 1 from the burner 2 and the air supply port 8, respectively. By separately supplying the combustion air in this way, the temperature of the flame formed by burning the liquid fuel by the burner 2 is reduced.

  Further, by burning the fuel in the vicinity of the burner 2 in the furnace 1 with a shortage of air, a part of nitrogen contained in the fuel is generated as a reducing agent, and a reaction for reducing NOx generated by the combustion to nitrogen is performed. Can be generated.

  For this reason, the NOx concentration at the furnace 1 outlet is reduced as compared with the case where all the combustion air is supplied from the burner 2. The remaining combustion air is supplied from the air supply port 8 into the furnace 1 to completely burn the fuel, thereby reducing the unburned amount.

  Combustion gas 10 generated by burning fuel in the furnace 1 by the burner 2 is mixed with combustion air supplied from the air supply port 7 to become a combustion gas flow 11, and heat disposed in the upper part of the furnace 1. After exchanging heat with the exchanger 12, it flows down through the flue 13 and is discharged from the chimney 14 to the atmosphere.

  Next, the structure of the spray nozzle according to the first embodiment of the present invention will be described in detail with reference to FIG.

  FIG. 2 shows a partial sectional view of the tip 20 of the spray nozzle 9 of this embodiment. In FIG. 2, the tip 20 of the spray nozzle 9 is configured such that the upstream side is connected to a supply system (not shown) of the liquid fuel (spray fluid) 21 and a supply system (not shown) of the spray medium 22. Has been.

  The tip 20 of the nozzle of the spray nozzle 9 of the present embodiment shown in FIG. 2 shows the tip 20 of the nozzle of the spray nozzle 9 having a plurality of jet outlets having the jet holes 23 and the jet holes 24. However, it is possible to provide a number of ejection holes in addition to these two. By providing a large number of ejection holes at the tip 20 of the nozzle of the spray nozzle 9, the amount of liquid fuel ejected from the spray nozzle 9 can be increased.

  Of the plurality of ejection holes provided in the tip 20 of the spray nozzle 9, the ejection hole 23, which is one of the ejection holes, ejects only the spray fluid 21 from the ejection hole 23.

  The spray fluid 21 guided from the upstream side of the ejection hole 23 swirls the spray fluid 21 and the spray fluid flow path 25 that causes the spray fluid 21 formed inside the nozzle tip 20 of the spray nozzle 9 to flow down. The swirling flow generator 26 is sequentially flowed down and supplied to the ejection holes 23, and the spray fluid 21 is swirled by the swirling flow generator 26 due to its own pressure and ejected from the ejection holes 23.

  The spray of the spray fluid 21 by the pressure spray method is atomized by the shearing force between the spray fluid 21 and the surrounding gas. Because of the momentum of the spray fluid 21 only, the momentum of the spray is smaller than that of the two-fluid spray. For this reason, the fine particles tend to stay in the vicinity of the spray nozzle 9.

  When an igniter is installed near the tip 20 of the spray nozzle and ignited, the fine particles of the spray fluid 21 are retained in the vicinity of the spray nozzle 9 by spraying from the ejection holes 23, so that the energy of the smaller than the large particles The electric spark can evaporate and burn the fine particles of the spray fluid 21.

  Once the fine particles of the spray fluid 21 start to burn, the combustion heat ignites the nearby particles, the flame spreads, and a liquid fuel flame can be formed. For this reason, it becomes easy to reliably ignite with a small capacity igniter.

  In the spray nozzle 9 of the present embodiment, among the plurality of spray holes provided at the tip 20 of the spray nozzle 9, the spray hole 24, which is the other spray hole, flows the spray fluid 21 and the spray medium 22. The mixture is mixed in the passage and ejected from the ejection hole 24.

  The spraying medium 22 guided from the upstream side of the ejection hole 24 flows down the spraying medium flow path 27 for spraying the spraying medium 22 formed inside the tip 20 of the spraying nozzle 9 and the spraying fluid 21. The spray fluid flow path 28 to be mixed is mixed at the merge flow path 29 to be mixed, and the mixed fluid of the spray medium 22 and the spray fluid 21 flowing down the merge flow path 29 is supplied to the ejection holes 24. And ejected from the ejection hole 24.

  In such a two-fluid spray, the spray fluid 21 is atomized by mixing the spray fluid 21 and the spray medium 22. Since the spray fluid 21 and the spray medium 22 each have a momentum, the spray momentum is larger than that of the pressure spray type spray. For this reason, the spray particles reach a position away from the fuel nozzle 9. Moreover, since the momentum is large, the surrounding air is engulfed and burned, so that the amount of dust can be reduced.

  The spraying medium is generally jetted by applying pressure to steam or air, but other gases such as combustion exhaust gas can also be used.

  In the spray nozzle 9 of the present embodiment, the spray of only the spray fluid 21 sprayed from one ejection hole 23 as described above, and the mixed fluid of the spray fluid 21 sprayed from the other ejection hole 24 and the spray medium 22 are mixed. By forming the two types of sprays, i.e., spraying, it is possible to achieve both the promotion of ignition and the reduction of the amount of dust generation.

  As described above, according to the present embodiment, fine particles are collected in the vicinity of the spray nozzle to promote ignition, and the momentum of the dust is generated by increasing the momentum of the spray to promote the mixing of the spray particles and the combustion air. It is possible to realize a reduced spray nozzle with good combustion performance and a combustion apparatus having this spray nozzle.

  By using the spray nozzle 9 of the present embodiment shown in FIG. 2 described above, two types of spray can be formed by one spray nozzle 9. That is, the spray is formed from one of the plurality of spray holes 23 and 24 by the pressure spray method, and the spray is formed from the other spray hole 24 by the two-fluid spray method.

  FIG. 3 is an enlarged view of a portion of the burner 2 installed in the boiler of the combustion apparatus of FIG. 1, and shows an example of the burner 2 in which the spray nozzle 9 of this embodiment shown in FIG. . FIG. 4 is a partial view of the vicinity of the spray nozzle 9 of the burner 2 shown in FIG.

  In the burner 2 of the combustion apparatus shown in FIG. 3, the spray nozzle 9 of the above-described embodiment is installed on the central axis of the burner, and a flow path 34 for flowing down the spray fluid and the spray medium is disposed. An obstacle 46 for stabilizing the flame is provided near the tip of the nozzle 9.

  As the obstacle 46, a swirl flow generator or a baffle plate having a slit is generally used. Two types of sprays 50 and 51 are sprayed from the spray nozzle 9 into the furnace 1.

  Combustion air is supplied from a wind box 37 in three flow paths. The primary flow path 31, the secondary flow path 32, and the tertiary flow path 33 are located closer to the center spray nozzle 9. The primary flow path 31, the secondary flow path 32, and the tertiary flow path 33 are ejected into the furnace 1 as primary air 43, secondary air 44, and tertiary air 45, respectively.

  The outer periphery of the tertiary flow path 33 is connected to the furnace wall 40. A heat transfer tube 41 is provided on the furnace wall 40. Further, the swirl flow generators 38 and 39 and the guide plate 42 are used to change the direction in which the combustion air is ejected to suppress the generation of dust and NOx. The primary flow path 31 to the tertiary flow path 33 are each configured to control the flow rate by a damper (not shown).

An igniter 36 is installed near the spray nozzle 9. As shown in FIG. 4, by approaching the igniter 36, the spray hole 23, which is installed at the tip of the spray nozzle 9 and generates a spray by the pressure spray method, is near the tip of the igniter 36. Fine particles stay. For this reason, since the igniter 36 can evaporate and burn the fine particles with an electric spark of low energy, it becomes easy to reliably ignite with a small-capacity igniter.
When the pressure spray type ejection hole 23 and the two-fluid spray type ejection hole 24 are provided at the tip of the spray nozzle 9, the pressure spray type ejection holes 23 for ejecting the fine particles are one or two, and the remaining many are two. It is desirable to use the fluid spray type ejection hole 24. FIG. 4 shows a case where one spray hole 23 and three spray holes 24 are provided at the tip of the spray nozzle 9. At this time, the pressure spray type ejection hole 23 is responsible for ignition and stabilization of the flame by generating fine particles. Further, the two-fluid spray type injection hole 24 sprays a large volume of liquid fuel as compared with the injection hole 23, and this spray has a high momentum and is easily mixed with the combustion air. Therefore, by increasing the number of ejection holes 24 as compared with the ejection holes 23, the amount of liquid fuel that can be sprayed by the spray nozzle 9 can be increased and the amount of combustion can be increased.

  1 and FIG. 3 show a case where a number of two-fluid spray type injection holes 24 are provided downward on the upstream side of the furnace 1 and the amount of momentum of the downward spray is large. The ejection hole 24 has a large ejection amount of liquid fuel. By increasing the number of spray holes downward, the proportion of spray particles sprayed downward increases. For this reason, since spray particles stay in the furnace 1 and the time for the combustion reaction increases, the amount of unburned fuel is reduced, and the amount of dust discharged at the furnace 1 outlet can be suppressed.

  In the present embodiment, the case where liquid fuel is used as the combustion device is shown, but the present invention can also be applied 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 9 into the furnace 1, the above effect can be obtained.

  According to the above-described embodiment, fine particles are collected in the vicinity of the spray nozzle to promote ignition, and the momentum of the spray is increased to promote the mixing of the spray particles and the combustion air, thereby reducing the amount of dust generated. It becomes possible to realize a spray nozzle having good combustion performance and a combustion apparatus having this spray nozzle.

  FIG. 5 shows an example of the tip 20 of the spray nozzle 9 according to the second embodiment of the present invention. The difference between the tip 20 of the spray nozzle 9 of the present embodiment shown in FIG. 5 and the tip 20 of the spray nozzle 9 of the first embodiment shown in FIG. For this reason, description of the structure common to both is abbreviate | omitted, and only the part which concerns on this ejection hole 23 is demonstrated below.

  In the tip part 20 of the spray nozzle 9 of the present embodiment, only the spray fluid 21 is ejected from the ejection hole 23. The spray fluid 21 guided from the upstream side of the ejection hole 23 flows down the two spray fluid passages 25 formed inside the nozzle tip 20 of the spray nozzle 9. 25, and a flow path 61 provided orthogonal to the coupling flow path 60 is communicated with the ejection hole 23, so that the upstream side of the ejection hole 23 is provided. The spray fluid 21 guided from the side is ejected from the ejection hole 23 through the spray fluid channel 25, the coupling channel 60, and the channel 61. For this reason, the ejection hole 23 is located at the intersection of the coupling channel 60 and the channel 61.

  In the tip portion 20 of the spray nozzle 9 of the present embodiment, the two spray fluids 21 flowing down from the two spray fluid flow paths 25 are opposed to the intersection with the flow path 61 in the combined flow path 60. Flowing. For this reason, two spray fluids 21 facing each other at the intersection with the channel 61 collide, and the spray of the spray fluid 21 ejected from the ejection hole 23 by the collision force is perpendicular to the upstream coupled channel 60. A fan-shaped spray is formed in the direction.

  The liquid film formed at the intersecting portion (ejection hole) 23 is split from the shearing force with the surrounding gas and atomized after ejecting from the intersecting portion. Such a pressure spray method is generally called fan spray spray.

  In the fan spray type spray, the spray fluid 21 collides at the intersecting portion (spout hole) 23 and expands in the perpendicular direction, so that the momentum in the axial direction of the spout hole 23 decreases. For this reason, the spray particles of the spray fluid 21 tend to stay in the vicinity of the spray nozzle 9. By increasing the concentration of the spray particles in the vicinity of the spray nozzle 9, the flame propagation speed between the spray particles is increased, and the formation of the flame is facilitated.

  Further, in the fan spray type spray, compared with the spray method using a swirl flow that is general in pressure spraying, the spray from the individual ejection holes is less likely to interfere due to the fan-type spray. For this reason, there is an advantage that combustion failure such as generation of soot and dust due to large particles generated by the interference of the spray and combustion delay are suppressed.

  In the spray nozzle 9 of the above-described embodiment shown in FIG. 5, the liquid fuel (spray fluid) 21 intersects the spray fluid passage 25 upstream of the spray hole 23 in the spray hole 23 from which only the spray fluid 21 is ejected. It flows opposite to the part. For this reason, the spray fluid 21 which opposes in the intersection part collides, and a fan-shaped spray is formed in the orthogonal | vertical direction with the spray fluid flow path 25 of the upstream of the ejection hole 23 in the intersection part by the collision force. The liquid film formed at the intersecting portion is ejected from the intersecting portion, and then splits by the shearing force with the surrounding gas, thereby atomizing the spray fluid 21. Such a pressure spray method is generally called fan spray spray.

  In the fan spray type spray, the spray fluid 21 collides at the intersecting portion and expands in the right-angle direction, so that the momentum in the axial direction of the ejection hole 23 decreases. For this reason, the spray particles of the spray fluid 21 tend to stay in the vicinity of the spray nozzle 9. By increasing the concentration of the spray particles in the vicinity of the spray nozzle 9, the flame propagation speed between the spray particles is increased, and the formation of the flame is facilitated.

  Further, in the fan spray type spray, compared with the spray method using a swirl flow that is general in pressure spraying, the spray from the individual ejection holes is less likely to interfere due to the fan-type spray. For this reason, there exists an advantage which suppresses generation | occurrence | production of the soot and dust by the large particle which arises by interference of spraying, and suppresses the combustion failure, such as combustion delay.

  According to this embodiment, the combustion performance of collecting fine particles in the vicinity of the spray nozzle to promote ignition and increasing the momentum of the spray to promote mixing of the spray particles and combustion air to reduce the generation amount of dust. This makes it possible to realize a spray nozzle having good quality and a combustion apparatus having this spray nozzle.

  FIG. 6 shows a modification of the spray nozzle 9 according to the second embodiment of the present invention. The difference between the tip 20 of the spray nozzle 9 of the modification of the second embodiment shown in FIG. 6 and the tip 20 of the spray nozzle 9 of the second embodiment shown in FIG. It is a road structure. For this reason, description of the structure common to both is abbreviate | omitted, and only the part which concerns on this ejection hole 23 is demonstrated below.

  In the tip part 20 of the spray nozzle 9 of this modification, the spray fluid 21 and the spray medium 22 are mixed and ejected from the ejection hole 23. The spray fluid 21 guided from the upstream side of the ejection hole 23 flows down the two spray fluid flow paths 25 formed inside the nozzle tip 20 of the spray nozzle 9.

  Further, the spraying medium 22 guided from the upstream side of the ejection hole 23 flows down the two spraying medium flow paths 62 formed inside the nozzle tip 20 of the spray nozzle 9.

  A combined flow path 60 that couples the two spray fluid flow paths 25 and the two spray medium flow paths 62 is provided, and a flow path 61 provided orthogonal to the combined flow path 60 is further provided. By communicating with the ejection hole 23, the spray fluid 21 and the spray medium 22 guided from the upstream side of the ejection hole 23 merge in the coupling channel 60, and pass through the channel 61 from the ejection hole 23. Erupts.

  In the tip part 20 of the spray nozzle 9 of this modification, the two spray fluids 21 respectively flowing down from the two spray fluid flow paths 25 are opposed to the intersection with the flow path 61 in the combined flow path 60. Flowing. Further, two spraying media 22 respectively flowing down from the two spraying medium flow paths 62 join in the middle. For this reason, the first atomization of the spray fluid 21 proceeds by the merging of the spray medium 22, and the collision force at the intersecting portion increases. For this reason, atomization of the spray fluid 21 is promoted compared to the fan spray type spray that does not use the spray medium 22.

  Furthermore, atomization proceeds as described above. Therefore, by retaining the fine particles, the fine particles can be evaporated and burned with an electric spark with less energy than the large particles. Further, increasing the retention of fine particles makes it easier for the flame to spread. For this reason, it becomes easy to reliably ignite with a small capacity igniter.

  Also in this modification, the combustion performance of collecting particulates in the vicinity of the spray nozzle to promote ignition and increasing the momentum of the spray to promote mixing of the spray particles and combustion air to reduce the generation amount of dust. It is possible to realize a good spray nozzle and a combustion apparatus having this spray nozzle.

  Next, an example of the tip 20 of the spray nozzle 9 according to the third embodiment of the present invention is shown in FIG. The difference between the tip 20 of the spray nozzle 9 of the present embodiment shown in FIG. 7 and the tip 20 of the spray nozzle 9 of the first embodiment shown in FIG. For this reason, description of the structure common to both is abbreviate | omitted, and only the part which concerns on this ejection hole 23 is demonstrated below.

  In the tip part 20 of the spray nozzle 9 of the present embodiment, the spray hole 23 and the spray hole 24 are mixed from the spray fluid 21 and the spray medium 22 and ejected from the spray hole 23 and the spray hole 24, respectively.

  The atomizing fluid 21 guided from the upstream side of the ejection hole 23 flows down the atomizing medium flow path 64 that causes the atomizing medium 22 formed inside the nozzle tip 20 of the atomizing nozzle 9 to flow down, and the atomizing fluid 21. The spray fluid flow path 63 to be mixed is mixed at the merge flow path 63 to be mixed, and the mixed fluid of the spray medium 22 and the spray fluid 21 flowing down the merge flow path 65 is supplied to the ejection holes 23. And ejected from the ejection hole 23.

  In the tip portion 20 of the spray nozzle 9 of the present embodiment, both the ejection hole 23 and the ejection hole 24 are two-fluid sprays, but the cross-sectional area of the spray fluid channel 63 of the ejection hole 23 is the spray of the ejection hole 24. It is formed so as to be smaller than the cross-sectional area of the fluid flow path 28.

  For this reason, the ratio of the cross-sectional area of the spray medium flow path 64 to the spray fluid flow path 63 connected to the ejection hole 23 is the disconnection of the spray medium flow path 27 relative to the spray fluid flow path 28 connected to the spray hole 24. It becomes smaller than the ratio of the area.

  That is, the ratio of the cross-sectional area of the spray medium flow path 64 that flows down the spray medium 22 to the spray fluid flow path 63 that flows down the spray fluid 21 is larger in the spray holes 23 than in the spray holes 24. The flow rate ratio of the spray medium 22 to the fluid of the spray fluid 21 to be ejected is greater in the ejection holes 23.

  Alternatively, as another means, the flow rate of the spray fluid 21 flowing down through the spray fluid passage 63 ejected as a mixed fluid from the ejection holes 23 among the plurality of ejection holes 23, 24 provided in the tip portion 20 of the spray nozzle 9. The spray medium flow path with respect to the flow rate of the spray fluid 21 flowing down the spray fluid flow path 28 ejected as the mixed fluid from the ejection holes 24, rather than the ratio of the flow rate of the spray medium 22 flowing down the spray medium flow path 64 The control valve (not shown) installed so as to adjust the flow rate or pressure of the spraying medium 22 is adjusted so that the ratio of the flow rate of the spraying medium 22 flowing down 27 becomes larger. On the other hand, the supply pressure for supplying the spraying medium 22 ejected from the ejection hole 24 may be configured to be increased from the supply pressure for supplying the spraying medium 22 ejected from the ejection hole 23.

  Thus, atomization of the spray fluid 21 proceeds by using a large amount of the spray medium 22. Therefore, by retaining the fine particles, the fine particles can be evaporated and burned with an electric spark with less energy than the large particles. Further, increasing the retention of fine particles makes it easier for the flame to spread. For this reason, it becomes easy to reliably ignite with a small capacity igniter.

  In the spray nozzle 9 of this embodiment shown in FIG. 7, spray fluids (liquid fuel) 21 ejected from a plurality of intersections are ejected at different angles, and the spray particles of the spray fluid 21 have a wide range (angle). To spread. For this reason, the spray particles hardly collide with each other, and the generation of large particles can be suppressed.

  Furthermore, in the spray nozzle 9 based on the present embodiment, the ejection holes 23 and 24 are both two-fluid sprays, but in the spray holes 23 having a large ratio of the spray medium 22, the fine particles of the spray fluid 21 increase. Since the fine particles of the spray fluid 21 have a small inertial force, the fine particles of the spray fluid 21 are decelerated due to the speed difference with the surrounding gas and easily stay near the spray nozzle 9. When the concentration of the spray particles of the spray fluid 21 in the vicinity of the spray nozzle 9 is increased, the flame propagation speed between the spray particles is increased and the formation of the flame is facilitated.

Further, the spray particles 21 reach a position away from the fuel nozzle 9 by forming a spray of the spray fluid 21 having a large momentum from the spray holes 24 having a small ratio of the spray medium 22. Moreover, since the momentum is large, the surrounding air is engulfed and burned, and the amount of dust generation is small.
By changing the ratio of the spray medium 22, it becomes easy to keep the fine particles of the spray fluid 21 in the vicinity of the spray nozzle 9. For this reason, the usage-amount of the atomizing medium 22 used for atomization can be reduced, and the energy efficiency of a combustion apparatus can be improved.

  According to this embodiment, the combustion performance of collecting fine particles in the vicinity of the spray nozzle to promote ignition and increasing the momentum of the spray to promote mixing of the spray particles and combustion air to reduce the generation amount of dust. This makes it possible to realize a spray nozzle having good quality and a combustion apparatus having this spray nozzle.

  The present invention can be applied to a spray nozzle for atomizing liquid fuel and a combustion apparatus equipped with the spray nozzle.

  1: furnace, 2: burner, 3: combustion air supply system, 4: fuel supply system, 5: spray medium supply system, 6, 7: piping, 8: air supply port, 9: spray nozzle, 10: combustion Gas flow, 12: heat exchanger, 13: flue, 14: chimney, 20: tip of spray nozzle, 21: liquid fuel (spray fluid), 22: spraying medium, 23, 24: jet hole, 25 : Spray fluid flow path, 26: swirl flow generator, 27: spraying medium flow path, 28: spray fluid flow path, 29: confluence flow path, 31: 1 primary flow path, 32: secondary flow path, 33: Tertiary flow path, 34: flow path, 36: igniter, 37: wind box, 38, 39: swirl flow generator, 40: furnace wall, 41: heat transfer tube, 42; guide, 43: flow of primary air, 44: Secondary air flow, 45: Tertiary air flow, 46: Obstacle, 50, 51: Spray, 60: Combined flow , 61: passage, 63: atomizing fluid flow path, 64: atomizing medium flow path, 65: flow path.

Claims (6)

In a spray nozzle in which liquid fuel is sprayed as a spray fluid and sprayed, and another fluid is sprayed as a spray medium and pressure is mixed with the spray fluid and ejected.
A plurality of ejection holes for ejecting the spray fluid at the tip of the spray nozzle,
A spray fluid flow path is provided inside the tip of the spray nozzle to flow down the spray fluid and communicate with one of the spray holes so that only the spray fluid is ejected from one of the plurality of ejection holes provided.
Another spray fluid flow path for causing the spray fluid to flow down, and a spray medium flow path for causing the spray medium to flow down, so that a mixed fluid of the spray fluid and the spray medium is ejected from the other plurality of ejection holes. And a merging channel in which the atomizing fluid channel and the atomizing medium channel merge together are provided inside the tip of the spray nozzle, and the merging channel is communicated with the other ejection hole. Feature spray nozzle. In a spray nozzle in which liquid fuel is sprayed by applying pressure as a spray fluid, and another fluid is sprayed by applying pressure as a spray medium and mixing with the spray fluid,
A plurality of ejection holes for ejecting the spray fluid at the tip of the spray nozzle,
A plurality of spray fluid passages for allowing the spray fluid to flow down so that only the spray fluid is ejected from one of the plurality of ejection holes, and a coupling in which the spray fluids flowing through the plurality of spray fluid passages face each other A flow path is provided inside the tip of the spray nozzle, and the combined flow path is communicated with the one ejection hole, and the spray fluid intersecting in the combined flow path is ejected from the one ejection hole,
Another spray fluid flow path for causing the spray fluid to flow down, and a spray medium flow path for causing the spray medium to flow down, so that a mixed fluid of the spray fluid and the spray medium is ejected from the other plurality of ejection holes. In addition, each of the spray fluid flow channels and the spray medium flow channel is joined to each other inside the tip portion of the spray nozzle, and the merge flow channel is communicated with the other ejection hole to spray fluid. A spray nozzle characterized in that a mixed fluid of a spray medium and a spray medium is ejected from the other ejection hole. In a spray nozzle in which liquid fuel is sprayed by applying pressure as a spray fluid, and another fluid is sprayed by mixing with the spray fluid by applying pressure as a spray medium,
A plurality of ejection holes for ejecting the spray fluid at the tip of the spray nozzle,
A plurality of spray fluid passages for causing the spray fluid to flow down and a plurality of spray media for causing the spray medium to flow down so that the spray fluid and the spray medium are mixed and ejected from one of the plurality of ejection holes. A flow path and a combined flow path in which the spray fluid flowing through the plurality of spray fluid flow paths face each other are provided inside the tip of the spray nozzle, and the plurality of spray medium flow paths are provided in the combined flow path. And connecting the coupling channel to the one ejection hole,
Another spray fluid flow path for allowing the spray fluid to flow down and the spray medium to flow down so that a mixed fluid of another spray fluid and another spray medium is ejected from the other plurality of ejection holes. Provided in the inside of the tip of the spray nozzle is another spray medium flow path, and a merge flow path where the spray fluid flow path and the spray medium flow path merge, A spray nozzle characterized in that a mixed fluid of a spray fluid and a spray medium is ejected from the other ejection hole in communication with the ejection hole. In a spray nozzle in which liquid fuel is sprayed as a spray fluid and sprayed, and another fluid is sprayed as a spray medium and pressure is mixed with the spray fluid and ejected.
A plurality of ejection holes for ejecting the spray fluid at the tip of the spray nozzle,
A first spray fluid flow path for causing the spray fluid to flow down and a spray medium flow path for causing the spray medium to flow down so that a mixed fluid of the spray fluid and the spray medium is ejected from one of the plurality of ejection holes. And a merging channel in which the spray fluid channel and the spraying medium channel merge together is provided inside the tip portion of the spray nozzle, and the merging channel is communicated with one of the ejection holes for spraying. A mixed fluid of a fluid and a spray medium is ejected from the one ejection hole,
A second spray fluid flow path for causing the other spray fluid to flow down so that a mixed fluid of another spray fluid and another spray medium is ejected from the other ejection hole provided in the plurality; A second spray medium flow path for causing the medium to flow down, and a second merge flow path in which the spray fluid flow path and the spray medium flow path are joined to each other inside the tip of the spray nozzle. The second merging channel is communicated with the other ejection hole, and the mixed fluid of the spray fluid and the spray medium is ejected from the other ejection hole,
Further, the spray nozzle characterized in that the area of the first spray fluid channel is formed smaller than the area of the second spray fluid channel. In a spray nozzle in which liquid fuel is sprayed as a spray fluid and sprayed, and another fluid is sprayed as a spray medium and pressure is mixed with the spray fluid and ejected.
A plurality of ejection holes for ejecting the spray fluid at the tip of the spray nozzle,
A first spray fluid flow path for causing the spray fluid to flow down and a spray medium flow path for causing the spray medium to flow down so that a mixed fluid of the spray fluid and the spray medium is ejected from one of the plurality of ejection holes. And a merging channel in which the spray fluid channel and the spraying medium channel merge together is provided inside the tip portion of the spray nozzle, and the merging channel is communicated with one of the ejection holes for spraying. A mixed fluid of a fluid and a spray medium is ejected from the one ejection hole,
A second spray fluid flow path for allowing the other spray fluid to flow down so that a mixed fluid of another spray fluid and another spray medium is ejected from the other plurality of ejection holes, and the spray medium A second spraying medium flow path for causing the spraying fluid to flow down, and a second merging flow path in which the spray fluid flow path and the spraying medium flow path are merged, respectively, inside the tip of the spray nozzle, and The second confluence channel is communicated with the other ejection hole, and the mixed fluid of the spray fluid and the spray medium is ejected from the other ejection hole,
Further, the ratio of the flow rate of the spray medium flowing down the spray medium flow path to the flow rate of the spray fluid flowing down the first spray fluid flow path that is jetted as a mixed fluid from the one jet hole is the other. The ratio of the flow rate of another spraying medium flowing down the other spraying medium flow channel to the flow rate of another spraying fluid flowing down the second spraying fluid flow channel ejected as a mixed fluid from the ejection holes of A spray nozzle characterized by being configured so as to be large. A combustion furnace that burns fuel; a fuel supply system that supplies fuel to the combustion furnace and a carrier gas that transports the fuel; a combustion gas supply system that supplies combustion gas to the combustion furnace; and the fuel supply system And a combustion gas supply system connected to the burner for burning the fuel provided on the furnace wall of the combustion furnace, and heat exchange from the combustion exhaust gas generated by burning the fuel with the burner provided for the combustion furnace to the outside A combustion apparatus comprising: a heat exchanger to be discharged; and a flue for causing combustion exhaust gas after heat exchange with the heat exchanger of the combustion furnace to flow down to the outside of the combustion furnace,
A spray nozzle using the spray nozzle according to any one of claims 1 to 5, wherein a liquid fuel is used as at least a part of the fuel as the spray nozzle used in the combustion apparatus. Combustion equipment.

Images