JP2015064131A - Burner tip and combustion burner and boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a burner tip, a combustion burner, and a boiler in which the mixing of a fluid fuel and an atomizing medium is promoted, thereby reducing the atomized particle size of the fluid fuel to improve combustibility.SOLUTION: A burner tip is provided with: a mixing chamber 84 provided internally; a plurality of mixed fluid injection holes 82 of which base end parts communicate with a mixing chamber 84, of which front end parts are open, and that are arranged at predetermined intervals in a circumferential direction; stepped parts 91 that are provided in the mixed fluid injection holes 82 and increase passage areas; fuel supply passages 88 that supply a fluid fuel to the mixing chamber 84; and steam supply passages 87 that supply steam to the mixing chamber 84.

Description

  The present invention relates to a burner tip that is jetted in the form of a mist by mixing a fluid fuel and a spray medium, a combustion burner that forms a flame by a mixture of the fluid fuel and the spray medium ejected from the burner tip, and this combustion It relates to a boiler using a burner.

  A general oil-fired boiler has a furnace having a hollow shape and installed in a vertical direction, and a plurality of combustion burners are disposed on the furnace wall along the circumferential direction, and in a plurality of stages in the vertical direction. Has been placed. This combustion burner forms a flame by blowing the liquid fuel into the furnace in the state of being atomized by the spray medium, and can burn in the furnace. This furnace has a flue connected to the top, and this flue is provided with a superheater, reheater, economizer, etc. for recovering the heat of exhaust gas, and it was generated by combustion in the furnace. Heat exchange is performed between the exhaust gas and water, and steam can be generated.

  The combustion burner used in this oil-fired boiler is configured such that a burner tip is provided at the tip of a supply pipe for liquid fuel and spray medium. This burner tip can be ejected from a plurality of ejection holes formed at the tip after mixing the liquid fuel and the spray medium. When using fuel that generates a large amount of NOx and soot such as heavy fuel in the burner chip, it is necessary to ensure high combustibility and reduce NOx and soot. Therefore, it is conceivable to increase the number of ejection holes in the burner tip, but if the number of ejection holes is increased, the distance between adjacent ejection holes becomes shorter, and the jets interfere with each other to form a thin film. It is difficult to take in the air, which may cause poor ignition and poor combustion.

  As a burner chip that solves such a problem, for example, there is one described in the following patent document. An internal mixing atomizer described in Patent Document 1 includes a fuel supply path, a atomization medium supply path for atomizing fuel, a fuel supplied from the fuel supply path, and a atomization medium supplied from the atomization medium path. A mixing chamber for mixing and an ejection hole for ejecting the mixed fluid in the mixing chamber to the outside are provided. Further, the burner tip described in Patent Document 2 extends a plurality of spray medium ejection holes radially from the spray medium chamber, and forms a mixture ejection hole on the extension of the tip thereof to form the mixture ejection hole of the burner tip. Opened at the tip, the fuel injection hole is extended from the liquid fuel chamber, and the tip of the fuel injection hole is opened at the side surface of the mixture injection hole.

Japanese Patent Laid-Open No. 63-049615 JP 2010-127518 A

  As a burner chip, a mixture of a spray medium and liquid fuel in a mixing chamber provided therein as in Patent Document 1, and a mixture ejected from an ejection hole, and a mixture ejection hole in the middle of Patent Document 2 are disclosed. In some cases, the fuel injection hole is connected to the portion, and the liquid fuel is mixed with the spray medium and then injected. In the burner tip, as in Patent Document 2, a plurality of the mixture injection holes are arranged with a predetermined gap in the radial direction and the circumferential direction, thereby improving the atomization of the liquid fuel, and then the jet of the mixture Interference between each other can be prevented and combustibility can be improved. However, in the case of an internal mixing type burner chip having a mixing chamber, the diffusion of liquid fuel by the spray medium in this mixing chamber tends to be insufficient. Even if the liquid fuel film is formed on the inner wall surface of the mixture injection hole and the liquid fuel is dispersed to some extent uniformly in the mixing chamber, the liquid fuel film is passed through the mixture injection hole by the liquid fuel film. It becomes difficult to inject in a diffusion state.

  The present invention solves the above-described problem, and burner tip and combustion capable of improving the combustibility by reducing the spray particle size of the fluid fuel by promoting the mixing of the fluid fuel and the spray medium. The purpose is to provide a burner and a boiler.

  In order to achieve the above object, a burner chip according to the present invention comprises a chip body, a mixing chamber provided inside the chip body, a base end portion communicating with the mixing chamber, and a tip portion being a tip of the chip body. A plurality of mixed fluid ejection holes that are arranged at predetermined intervals in the circumferential direction of the chip body, a stepped portion that is provided in the mixed fluid ejection hole and expands a passage area, and fluid fuel is supplied to the mixing chamber A fluid fuel supply passage for supplying the fluid to the mixing chamber, and a spray medium supply passage for supplying the spray medium to the mixing chamber.

  Therefore, the fluid fuel supplied from the fluid fuel supply passage and the spray medium supplied from the spray medium supply passage are mixed in the mixing chamber, and the mixed fluid is ejected to the outside through the plurality of mixed fluid ejection holes. At this time, the mixed fluid ejection hole is easily formed with a fluid fuel film on the inner surface, but since a stepped portion is provided to enlarge the passage area, a shear force is generated when the mixed fluid passes through the stepped portion. The mixed fluid is removed from the fluid fuel film formed on the inner surface, and the mixed fluid can be ejected to the outside at a high speed. As a result, by promoting the mixing of the fluid fuel and the spray medium, the spray particle size of the fluid fuel can be reduced and the combustibility can be improved.

  In the burner tip of the present invention, the mixed fluid ejection hole has a circular passage shape, and the stepped portion is provided on the entire circumference, whereby the first ejection hole having a small diameter located on the mixing chamber side, A large-diameter second ejection hole located on the tip side of the chip body is provided.

  Therefore, when the mixed fluid transitions from the first ejection hole to the second ejection hole via the stepped portion, the passage area is suddenly expanded to receive a shearing force, and the mixed fluid adheres to the front surface of the inner peripheral surface. The fluid fuel is removed, and the mixed fluid can be ejected to the outside at a high speed.

  In the burner tip of the present invention, a plurality of the spray medium supply passages are provided on the base end side of the tip body, and the spray medium can be supplied to the mixing chamber along the axial direction. A plurality of nozzles are provided outside the spray medium supply passage on the base end side of the tip body, and fluid fuel can be supplied to the mixing chamber along the radial direction.

  Therefore, the fluid fuel is supplied from the outside to the atomized fluid supplied to the mixing chamber, so that the residence time of the fluid fuel in the mixing chamber can be secured for a long time, Mixing with the fluid can be facilitated.

  In the burner tip of the present invention, the mixed fluid between the uppermost portion and the lowermost portion of the tip body in the vertical direction with respect to the mixed fluid ejection holes at the uppermost portion and the lowermost portion of the tip body in the vertical direction. The ejection hole is arranged on the axial center side.

  Accordingly, it is possible to improve the combustibility by promoting the mixing of the fluid fuel and the surrounding air in the mixed fluid.

  The burner tip according to the present invention is characterized in that the plurality of mixed fluid ejection holes are formed radially about one point on the axial center of the tip body.

  Therefore, the processability of the plurality of mixed fluid ejection holes can be improved and the manufacturing cost can be reduced.

  In the burner tip of the present invention, the tip body is configured by connecting a spray plate in which the mixed fluid ejection hole is formed and a back plate in which the fluid fuel supply passage and the spray medium supply passage are formed, The mixing chamber is partitioned by the spray plate and the back plate, and a part of the fluid fuel supply passage is partitioned.

  Therefore, the chip body is divided into a spray plate and a back plate, and the mixing chamber and a part of the fluid fuel supply passage are partitioned by the spray plate and the back plate, thereby simplifying the structure of the chip body and reducing the cost. It can be.

  Further, the combustion burner of the present invention includes a wind box, a fuel compartment disposed in a vertical center portion of the wind box, a burner gun disposed in a central portion of the fuel compartment, and a vertical direction in the wind box. A pair of upper and lower auxiliary air compartments disposed at the upper and lower portions, and the burner tip is disposed at the tip of the burner gun.

  Therefore, the burner tip disposed at the tip of the burner gun is provided with a stepped portion that enlarges the passage area in the mixed fluid ejection hole, and therefore receives a shearing force when the mixed fluid passes through the stepped portion. The film of the fluid fuel formed on the inner surface of the mixed fluid can be removed, and the mixed fluid can be ejected to the outside at a high speed. As a result, by promoting the mixing of the fluid fuel and the spray medium, the spray particle size of the fluid fuel can be reduced and the combustibility can be improved.

  In the boiler according to the present invention, the combustion burner is disposed on the furnace wall in the boiler that burns fuel and air in a hollow furnace and collects heat by exchanging heat in the furnace. It is characterized by.

  Therefore, since the combustion burner is disposed on the furnace wall, the mixing of the fluid fuel and the spray medium is promoted, so that the spray particle size of the fluid fuel can be reduced and the combustibility can be improved.

  According to the burner tip, the combustion burner and the boiler of the present invention, since the stepped portion for expanding the passage area is provided in the mixed fluid ejection hole of the burner tip, the mixing of the fluid fuel and the spray medium is promoted to promote the spraying of the fluid fuel. Combustibility can be improved by reducing the particle size.

FIG. 1 is a cross-sectional view of the burner tip according to the first embodiment. FIG. 2 is a front view of the burner tip. 3 is a cross-sectional view taken along the line III-III of FIG. 1 in the burner tip. FIG. 4 is a schematic configuration diagram illustrating the oil-fired boiler according to the first embodiment. FIG. 5 is a front view illustrating the overall configuration of the combustion burner. FIG. 6 is a sectional view of the combustion burner. FIG. 7 is a cross-sectional view of the burner tip according to the second embodiment. FIG. 8 is a front view of the burner tip according to the third embodiment. 9 is a cross-sectional view taken along the line IX-IX in FIG. 8 showing a cross section of the burner tip.

  Exemplary embodiments of a burner tip, a combustion burner, and a boiler according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, and when there are two or more embodiments, what comprises combining each embodiment is also included.

[First Embodiment]
FIG. 4 is a schematic configuration diagram illustrating the oil-fired boiler according to the first embodiment.

  The oil-fired boiler according to the first embodiment uses heavy oil (or light oil, coal slurry, etc.) as fluid fuel as fuel, and steam (or high-pressure air) as a spray medium by a combustion burner (burner chip). , High pressure gas, flammable gas, etc.) and can be sprayed, burned in a furnace, and the heat generated by this combustion can be recovered.

  In the first embodiment, as shown in FIG. 4, the oil-fired boiler 10 is a conventional boiler, and includes a furnace 11 and a combustion device 12. The furnace 11 has a rectangular hollow shape and is installed along the vertical direction. A combustion device 12 is provided at the lower part of the furnace wall constituting the furnace 11.

  The combustion device 12 has a plurality of combustion burners 21 mounted on the furnace wall. In this embodiment, the combustion burner 21 is arranged in the circumferential direction, for example, at four equal intervals as one set, and in the vertical direction, for example, three sets, that is, three stages. Has been placed. The location and number of the combustion burners 21 are not limited to this.

  Each combustion burner 21 is connected to a fuel supply source 23 via a fuel supply pipe 22, and a flow rate adjusting valve 24 capable of adjusting the fuel supply amount is provided in the fuel supply pipe 22. Each combustion burner 21 is connected to a steam supply source 26 via a steam supply pipe 25, and a flow rate adjusting valve 27 capable of adjusting the steam supply amount is provided in the steam supply pipe 25. Further, the furnace 11 is provided with a wind box 28 at a position where each combustion burner 21 is mounted. One end of an air duct 29 is connected to the wind box 28, and the air duct 29 is connected to the other end. A blower 30 is attached.

  Therefore, each combustion burner 21 is supplied with fuel from the fuel supply source 23 through the fuel supply pipe 22 and with steam from the steam supply source 26 through the steam supply pipe 25. Further, each combustion burner 21 is supplied with combustion air heated by exchanging heat with exhaust gas from the air duct 19 to the wind box 28. Therefore, the combustion burner 21 mixes fuel and steam and atomizes them, and then injects them into the furnace 11 as a mixed fluid, and injects combustion air into the furnace 11 to form a flame in the furnace 11. it can.

  In the furnace 11, a flue 31 is connected to the upper part, and superheaters (super heaters) 32, 33 for recovering the heat of exhaust gas as a convection heat transfer part (heat recovery part) are connected to the flue 31. Heaters 34, 35 and economizers 36, 37, 38 are provided, and heat exchange is performed between exhaust gas generated by combustion in the furnace 11 and water.

  The flue 31 is connected to an exhaust gas pipe 39 through which exhaust gas subjected to heat exchange is discharged downstream. Although not shown, the exhaust gas pipe 39 is provided with a denitration device, an electrostatic precipitator, an induction blower, and a desulfurization device, and has a chimney at the downstream end.

  Therefore, when each combustion burner 21 injects the mixed fluid of fuel and steam into the furnace 11 in the combustion apparatus 12, the mixed fluid and air are burned in the furnace 11, and a flame is generated. When a flame is generated, combustion gas (exhaust gas) rises in the furnace 11 and is discharged to the flue 31.

  At this time, while water supplied from a water supply pump (not shown) is preheated by the economizers 36, 37, and 38, it is supplied to a steam drum (not shown) and supplied to each water pipe (not shown) on the furnace wall. Is heated to become saturated steam and fed into a steam drum (not shown). Further, saturated steam of a steam drum (not shown) is introduced into the superheaters 32 and 33 and is heated by the combustion gas. The superheated steam generated by the superheaters 32 and 33 is supplied to a power plant (not shown) (for example, a turbine). Further, the steam taken out during the expansion process in the turbine is introduced into the reheaters 34 and 35, overheated again, and returned to the turbine. In addition, although the furnace 11 was demonstrated as a drum type | mold (steam drum), it is not limited to this structure.

  Thereafter, the exhaust gas that has passed through the economizers 36, 37, and 38 of the flue 31 is removed with harmful substances such as NOx by a catalyst in a denitration device (not shown) in the exhaust gas pipe 39, and the particulate matter is collected by an electric dust collector. Is removed, and after the sulfur content is removed by the desulfurizer, it is discharged from the chimney into the atmosphere.

  First, the combustion device 12 will be described in detail. The combustion burners 21 constituting the combustion device 12 have substantially the same configuration. FIG. 5 is a front view showing the overall configuration of the combustion burner, and FIG. 6 is a cross-sectional view of the combustion burner.

  In the combustion burner 21, as shown in FIGS. 5 and 6, the wind box 28 has a box shape and is partitioned into a fuel compartment 53, an upper auxiliary air compartment 54, and a lower auxiliary air compartment 55 by partition plates 51 and 52. ing. The fuel compartment 53 is disposed in the center of the wind box 28 in the vertical direction, the upper auxiliary air compartment 54 is disposed in the upper part of the wind box 28 in the vertical direction, and the lower auxiliary air compartment 55 is disposed in the lower part.

  The fuel compartment 53 has a fuel air nozzle 56 and upper and lower fuel auxiliary air nozzles 57, 58. The fuel air nozzle 56 has a burner gun 59 disposed at the center thereof, and a flame stabilizer 60 around the fuel nozzle 53. Is arranged. On the other hand, the upper auxiliary air compartment 54 has an auxiliary air nozzle 61, and the lower auxiliary air compartment 55 has an auxiliary air nozzle 62. The fuel air nozzle 56, the upper and lower fuel auxiliary air nozzles 57 and 58, and the auxiliary air nozzles 61 and 62 can be tilted up and down.

  Accordingly, the combustion air is supplied to the fuel compartment 53 and the auxiliary air compartments 54 and 55 in the wind box 28 at a predetermined flow rate, and the primary air is fed into the fuel compartment 53, and the auxiliary air compartments 53 and 54 are supplied. Secondary air is fed into the. Most of the primary air sent into the fuel compartment 53 is jetted into the furnace 11 as effective primary air from the fuel air nozzle 56 and the fuel auxiliary air nozzles 57 and 58 at a high speed. Most of the secondary air sent into the auxiliary air compartments 54 and 55 is ejected from the auxiliary air nozzles 61 and 62 into the furnace 11 at a high speed.

  Fuel and steam are pumped to the burner gun 59, sprayed onto the furnace 11 by a burner tip 71, which will be described later, attached to the tip of the burner gun 59, and ignited by an ignition source (not shown) to form a flame. The flame is held by the swirl flow when the effective primary air passes through the flame holder 60, and combustion is continued. In the flame, the combustion is continued from the vicinity of the ignition point to the first half of the flame by primary air, and from the latter half to the completion of the combustion by effective secondary air.

  Next, the burner chip 71 will be described. 1 is a cross-sectional view of the burner tip according to the first embodiment, FIG. 2 is a front view of the burner tip, and FIG. 3 is a cross-sectional view of the burner tip taken along line III-III in FIG.

  As shown in FIGS. 1 to 3, the burner tip 71 includes a spray plate 72 and a back plate 73 as a tip body, and is integrally connected by a fastening ring (not shown).

  The spray plate 72 has a cylindrical shape in which the base end (right side in FIG. 1) is open and the tip end (left side in FIG. 1) is closed, and has a cylindrical shape so as to open to the base end portion. A first recess 81 is formed. Further, the spray plate 72 has a plurality of mixed fluid ejection holes 82 formed at the tip. The mixed fluid ejection holes 82 have a proximal end portion communicating with the first recess 81 and a distal end portion opened to the outside. A plurality of the mixed fluid ejection holes 82 are provided at equal intervals in the circumferential direction around the axis O1 of the burner tip 71 (this embodiment). Then, 10) are provided. In this case, each mixed fluid ejection hole 82 is formed radially around one point O 2 on the axis O 1 of the burner tip 71 and has an inner diameter smaller than the inner diameter of the mixing chamber 84.

  The back plate 73 has a disk shape, and a second recess 83 having a cylindrical shape is formed at the tip. The second recess 83 formed in the back plate 73 is opposed to the first recess 81 formed in the spray plate 72, and the recesses 81 and 83 are set to have substantially the same diameter. In the present embodiment, the first recess 81 and the second recess 83 form a mixing chamber 84, and each mixed fluid ejection hole 82 communicates with the mixing chamber 84 at the base end.

  In the back plate 73, an ejection chamber 85 is formed in a ring shape along the circumferential direction on the outer peripheral side of the second recess 83 (mixing chamber 84). The ejection chamber 85 communicates with the second recess 83 (mixing chamber 84) via a plurality of (eight in the present embodiment) communication passages 86. That is, each communication path 86 is formed along the radial direction (radial direction) of the back plate 73, one end communicates with the inner peripheral surface of the ejection chamber 85, and the other end communicates with the outer peripheral surface of the second recess 83. Communicate.

  In addition, the back plate 73 is connected to the fuel supply pipe 22 (fuel supply path 22a) and the steam supply pipe 25 (steam supply path 25a) at the base end. The back plate 73 is provided with a plurality of steam supply passages (spray medium supply passages) 87 for supplying steam from the steam supply passage 25a to the mixing chamber 84. Each of the steam supply passages 87 is provided in the back plate 73 along the longitudinal direction thereof, the base end portion thereof communicates with the steam supply passage 25a, and the distal end portion thereof communicates with the second recess 83, so that the mixing chamber Steam can be supplied to 84.

  Each back plate 73 is provided with a plurality of fuel supply passages (fluid fuel supply passages) 88 for supplying fuel from the fuel supply passage 22a to the mixing chamber 84 from the outer peripheral side thereof. The fuel supply passages 88 are provided in the back plate 73 along the longitudinal direction, the base end portion communicates with the fuel supply passage 22a, and the distal end portion communicates with the ejection chamber 85. Fuel can be supplied to the mixing chamber 84 through 86.

  In this case, the fuel supply pipe 22 and the steam supply pipe 25 are double pipes, the steam supply pipe 25 is located inside, and the fuel supply pipe 22 is disposed outside the steam supply pipe 25, thereby supplying fuel. A path 22a and a steam supply path 25a are formed. And the burner chip | tip 71 is attached to the front-end | tip part of this double pipe (the fuel supply piping 22, the steam supply piping 25) so that replacement | exchange is possible.

  Therefore, the steam in the steam supply path 25 a passes through the plurality of steam supply passages 87 and supplies the steam to the mixing chamber 84 along the axial direction of the burner tip 71. On the other hand, the fuel in the fuel supply path 22 a is supplied to the ejection chamber 85 through the plurality of fuel supply passages 88, and from the ejection chamber 85 through the plurality of communication paths 86 to the mixing chamber 84. Fuel can be supplied along the radial direction.

  Further, the burner tip 71 is provided with a stepped portion 91 that enlarges the passage area in each mixed fluid ejection hole 82. That is, the mixed fluid ejection hole 82 has a circular passage shape, and has a predetermined length so that the mixing chamber 84 communicates with the outside. The mixed fluid ejection hole 82 is provided with a stepped portion 91 in the middle of the length direction (injection direction of the mixed fluid) over the entire circumference, so that the first ejection hole 92 having a small diameter located on the mixing chamber 84 side. And the large diameter 2nd ejection hole 93 located in the front end side opened outside is formed.

  The first ejection hole 92 and the second ejection hole 93 each have a circular passage shape, and the circular passages are located concentrically. The second ejection hole 93 on the distal end side has a larger diameter than the first ejection hole 92 on the mixing chamber 84 side, and the passage area of the mixed fluid ejection hole 82 is rapidly expanded in the middle. Become. The stepped portion 91 is located between the first ejection hole 92 and the second ejection hole 93, and is a surface orthogonal to the length direction (the ejection direction of the mixed fluid) in the mixed fluid ejection hole 82, In the circumferential direction of the mixed fluid ejection hole 82, a ring shape having the same radial length is formed. In this case, it is desirable that the first ejection hole 92 has an inner diameter that is conventionally used, and a second ejection hole 93 that expands from the first ejection hole 92 is provided.

  Here, the effect | action of the burner chip | tip 71 (burner gun 59) of 1st Embodiment mentioned above is demonstrated in detail. In FIG. 1, the fuel flow is represented by black arrows, the steam flow is represented by white arrows, and the mixed fluid in which fuel and steam are mixed is represented by hatched arrows.

  As shown in FIG. 1, when the steam is supplied through the steam supply pipe 25 by the burner tip 71, this steam is supplied to the mixing chamber 84 along the direction of the axis O <b> 1 through the plurality of steam supply passages 87. . When the fuel is supplied through the fuel supply pipe 22, the fuel is supplied from the outside along the radial direction to the mixing chamber 84 through the plurality of fuel supply passages 88, the ejection chamber 85, and the communication passage 86.

  Then, in the mixing chamber 84, the fuel supplied from the outside along the radial direction collides with the vapor supplied along the direction of the axis O1, collides with each other, and is mixed. That is, the fuel supplied to the mixing chamber 84 from the outside so as to be substantially orthogonal to the steam flowing toward the mixed fluid ejection hole 82 side along the axis O1 direction collides with the steam. It will be diffused and mixed. Further, since the fuel is supplied to the mixing chamber 84 in the radial direction, the fuel does not flow linearly toward the mixed fluid ejection hole 82 side, and the residence time of the fuel in the mixing chamber 84 becomes long and diffused by the steam. It becomes easy to be done.

  The mixed fluid efficiently mixed in the mixing chamber 84 flows forward through the mixing chamber 84 and is ejected (sprayed) to the outside through the mixed fluid ejection holes 82. At this time, the mixed fluid is ejected from the first ejection hole 92 to the outside through the stepped portion 91 and the second ejection hole 93. When the mixed fluid of fuel and steam passes through the mixed fluid ejection hole 82 due to the influence of the viscosity of the fuel, the fuel adheres to the inner surface of the mixed fluid and easily forms a fuel liquid film. However, in the present embodiment, a stepped portion 91 that enlarges the passage area is provided in the mixed fluid ejection hole 82. Therefore, when the mixed fluid passes through the stepped portion 91, the mixed fluid receives a shearing force, and the mixed fluid removes the fuel liquid film formed on the inner surface of the mixed fluid ejection hole 82 or adheres to the inner surface. Therefore, the spray particle size of the fluid fuel can be reduced.

  As described above, in the burner chip according to the first embodiment, the mixing chamber 84 provided in the interior and the base end portion communicate with the mixing chamber 84 and the tip end portion is opened and arranged at predetermined intervals in the circumferential direction. A plurality of mixed fluid ejection holes 82, a stepped portion 91 provided in the mixed fluid ejection holes 82 to enlarge the passage area, a fluid fuel supply passage 88 that supplies fluid fuel to the mixing chamber 84, and a steam mixing chamber 84 And a steam supply passage 87 for supplying to the steam generator.

  Therefore, the fuel supplied from the fuel supply passage 88 and the steam supplied from the vapor supply passage 87 are mixed in the mixing chamber 84, and the mixed fluid is ejected to the outside through the plurality of mixed fluid ejection holes 82. At this time, the mixed fluid ejection hole 82 is easy to form a fuel liquid film on the inner surface, but since the stepped portion 91 that enlarges the passage area is provided, the mixed fluid passes through the stepped portion 91. The fuel fluid film formed on the inner surface by the shearing force is removed, and the fluid mixture can be ejected to the outside at a high speed. As a result, by promoting the mixing of fuel and steam, the spray particle size of the fuel can be reduced and the combustibility can be improved.

  In the burner tip of the first embodiment, the mixed fluid ejection hole 82 has a circular passage shape, and the stepped portion 91 is provided on the entire circumference, so that the small diameter first ejection hole 92 located on the mixing chamber 84 side and A large-diameter second ejection hole 93 located on the distal end side is provided. Therefore, when the mixed fluid transitions from the first ejection hole 92 to the second ejection hole 93 via the stepped portion 91, the passage area is suddenly expanded to receive a shearing force, and the mixed fluid is brought to the front surface of the inner peripheral surface. The adhering fuel liquid film is removed, and the mixed fluid can be ejected to the outside at a high speed.

  In the burner chip of the first embodiment, a plurality of steam supply passages 87 are provided in the back plate 73, steam can be supplied to the mixing chamber 84 along the axial direction, and the fuel supply passage 88 is supplied to the back plate 73 with the steam supply passage 87. A plurality of fuel tanks are provided on the outer side so that fuel can be supplied to the mixing chamber 84 along the radial direction. Therefore, fuel is supplied from the outside to the steam supplied to the mixing chamber 84, and the residence time of the fuel in the mixing chamber 84 can be secured for a long time. Can promote mixing.

  In the burner tip of the first embodiment, the spray plate 72 in which the mixed fluid ejection hole 82 is formed and the back plate 73 in which the fuel supply passage 88 and the steam supply passage 87 are formed are connected, and the spray plate 72 and the back plate are connected. 73 divides the mixing chamber 84, and divides the ejection chamber 85 and the communication passage 86 that constitute the fuel supply passage. Therefore, the structure of the burner chip 71 can be simplified and the cost can be reduced.

  In addition, the combustion burner of the first embodiment has the wind box 28, the fuel compartment 53, the burner gun 59, and a pair of upper and lower auxiliary air compartments 54, 55, and the burner tip 71 is disposed at the tip of the burner gun 59. doing. The boiler according to the first embodiment is a boiler that burns fuel and air in a hollow furnace 11 and recovers heat by exchanging heat in the furnace 11, and a combustion burner 21 on the furnace wall. Is arranged.

  Therefore, the burner tip 71 arranged at the tip of the burner gun 59 is provided with the stepped portion 91 that enlarges the passage area in the mixed fluid ejection hole 82, so that the mixed fluid passes through the stepped portion 91. The fuel fluid film formed on the inner surface of the mixed fluid is removed by receiving the shearing force, and the mixed fluid can be ejected to the outside at a high speed. As a result, by promoting the mixing of the fuel and the vapor, the spray particle size of the fluid fuel can be reduced and the combustibility can be improved.

[Embodiment 2]
FIG. 7 is a cross-sectional view of the burner tip according to the second embodiment. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  In the second embodiment, as shown in FIG. 7, the burner chip 101 includes a spray plate 72 and a back plate 73. The spray plate 72 has a first concave portion 81 formed at the proximal end portion and a plurality of mixed fluid ejection holes 82 formed at the distal end portion. The back plate 73 has a second recess 83 formed at the tip, and the first recess 81 and the second recess 83 constitute a mixing chamber 84.

  In the back plate 73, an ejection chamber 85 is formed on the outer peripheral side of the second recess 83, and the ejection chamber 85 communicates with the second recess 83 via a plurality of communication paths 86. Further, the back plate 73 is connected to the fuel supply pipe 22 and the steam supply pipe 25 at the base end portion, and is provided with a plurality of fuel supply passages 88 for supplying fuel from the fuel supply path 22a to the mixing chamber 84, and for supplying steam. A plurality of steam supply passages 87 that are supplied from the outer peripheral side to the mixing chamber 84 from the steam supply path 25a are provided.

  Further, the burner tip 101 is provided with a stepped portion 91 that enlarges the passage area in each mixed fluid ejection hole 82. That is, the mixed fluid ejection hole 82 has a circular passage shape, and has a predetermined length so that the mixing chamber 84 communicates with the outside. The mixed fluid ejection hole 82 is provided with a stepped portion 91 in the middle of the length direction (injection direction of the mixed fluid) over the entire circumference, so that the first ejection hole 92 having a small diameter located on the mixing chamber 84 side. And a large-diameter second ejection hole 93 located on the distal end side that opens to the outside.

  Therefore, when fuel is supplied through the fuel supply pipe 22, this fuel is supplied along the direction of the axis O <b> 1 to the mixing chamber 84 through the plurality of fuel supply passages 88. When the steam is supplied through the steam supply pipe 25, the steam is supplied from the outside along the radial direction to the mixing chamber 84 through the plurality of steam supply passages 87, the ejection chamber 85, and the communication passage 86.

  Then, in the mixing chamber 84, the vapor supplied from the outside along the radial direction collides with the fuel supplied along the direction of the axial center O1, collides with each other, and is mixed. That is, the vapor supplied to the mixing chamber 84 from the outside so as to be substantially orthogonal to the fuel flowing to the mixed fluid ejection hole 82 side along the axis O1 direction collides with the fuel. It will be diffused and mixed.

  The mixed fluid efficiently mixed in the mixing chamber 84 flows forward through the mixing chamber 84 and is ejected (sprayed) to the outside through the mixed fluid ejection holes 82. At this time, the mixed fluid is ejected from the first ejection hole 92 to the outside through the stepped portion 91 and the second ejection hole 93. When the mixed fluid of fuel and steam passes through the mixed fluid ejection hole 82 due to the influence of the viscosity of the fuel, the fuel adheres to the inner surface of the mixed fluid and easily forms a fuel liquid film. However, in the present embodiment, a stepped portion 91 that enlarges the passage area is provided in the mixed fluid ejection hole 82. Therefore, when the mixed fluid passes through the stepped portion 91, the mixed fluid receives a shearing force, and the mixed fluid removes the fuel liquid film formed on the inner surface of the mixed fluid ejection hole 82 or adheres to the inner surface. Therefore, the spray particle size of the fluid fuel can be reduced.

  As described above, in the burner tip according to the second embodiment, the mixing chamber 84 provided in the interior and the base end portion communicate with the mixing chamber 84 and the tip end portion is opened and arranged at predetermined intervals in the circumferential direction. A plurality of mixed fluid ejection holes 82, a stepped portion 91 provided in the mixed fluid ejection holes 82 to expand the passage area, a fluid fuel supply passage 88 that supplies fluid fuel to the mixing chamber 84, and a fluid fuel supply passage 88 And a steam supply passage 87 for supplying steam to the mixing chamber 84.

  Therefore, the steam supplied from the steam supply passage 87 in the radial direction of the mixing chamber 84 collides with the fuel supplied from the fuel supply passage 88 in the axial direction of the mixing chamber 84 and is mixed, and a plurality of mixed fluids are mixed. Are ejected to the outside through the mixed fluid ejection holes 82. At this time, the mixed fluid ejection hole 82 is easy to form a fuel liquid film on the inner surface, but since the stepped portion 91 that enlarges the passage area is provided, the mixed fluid passes through the stepped portion 91. The fuel fluid film formed on the inner surface by the shearing force is removed, and the fluid mixture can be ejected to the outside at a high speed. As a result, by promoting the mixing of fuel and steam, the spray particle size of the fuel can be reduced and the combustibility can be improved.

[Embodiment 3]
FIG. 8 is a front view of the burner tip according to the third embodiment, and FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  In the third embodiment, as shown in FIGS. 5 and 6, the combustion burner 21 is configured by providing a wind compartment 28 with a fuel compartment 53, an upper auxiliary air compartment 54, and a lower auxiliary air compartment 55. The fuel compartment 53 has a fuel air nozzle 56. The fuel air nozzle 56 has a burner gun 59 disposed at the center thereof, and a flame holder 60 disposed around it. The burner gun 59 is provided with a burner chip 111 (described later) at the tip.

  As shown in FIGS. 8 and 9, the burner chip 111 includes a spray plate 72 and a back plate 73. The spray plate 72 is formed with a first recess 81 at the base end and a plurality of mixed fluid ejection holes 112, 113, 114 at the tip. The back plate 73 has a second recess 83 formed at the tip, and the first recess 81 and the second recess 83 constitute a mixing chamber 84.

  In the back plate 73, an ejection chamber 85 is formed on the outer peripheral side of the second recess 83, and the ejection chamber 85 communicates with the second recess 83 via a plurality of communication paths 86. Further, the back plate 73 is connected to the fuel supply pipe 22 and the steam supply pipe 25 at the base end portion, and is provided with a plurality of steam supply passages 87 for supplying steam from the steam supply path 25a to the mixing chamber 84, and for supplying fuel. A plurality of fuel supply passages 88 that are supplied from the outer peripheral side to the mixing chamber 84 from the fuel supply path 22a are provided.

  In the present embodiment, the mixed fluid ejection holes 113 and 114 between the uppermost part and the lowermost part in the vertical direction are on the axis O1 side with respect to the mixed fluid ejection holes 112 at the uppermost part and the lowermost part in the vertical direction. Is arranged. In other words, the plurality of mixed fluid ejection holes 112, 113, 114 are formed radially around one point O 2 on the axis O 1. The mixed fluid ejection holes 112 at the uppermost and lowermost portions in the vertical direction are formed such that the axis O11 has an inclination angle θ1 with respect to the axis O1. Further, the mixed fluid ejection holes 113 and 114 between the uppermost part and the lowermost part in the vertical direction are formed such that the axes O12 and O13 are inclined at angles θ2 and θ3 with respect to the axis O1. Here, the relationship between the inclination angles θ1, θ2, and θ3 is θ1> θ2> θ3. From the inclination angle θ1 of the mixed fluid ejection hole 112 at the uppermost portion in the vertical direction and the lowermost portion, the uppermost portion in the vertical direction. Is set smaller toward the inclination angles θ2 and θ3 of the mixed fluid ejection holes 113 and 114 between the lowermost portion and the lowermost portion.

  Therefore, the two mixed fluid ejection holes 112 open along the arc C1 centered on the axis O1, and the four mixed fluid ejection holes 113 open along the arc C2 centered on the axis O1, The four mixed fluid ejection holes 114 open along an arc C3 centered on the axis O1. Here, the relationship between the arcs C1, C2, and C3 is C1> C2> C3. In addition, the mixed fluid ejection hole is not provided in the horizontal position on the left and right with respect to the axis O1, that is, the position of the axis O14.

  Further, the burner tip 111 is provided with stepped portions 121, 124, and 127 that enlarge the passage area in the mixed fluid ejection holes 112, 113, and 114. That is, the mixed fluid ejection holes 112, 113, and 114 have a circular passage shape, and are opened with a predetermined length so that the mixing chamber 84 communicates with the outside. The mixed fluid ejection holes 112, 113, 114 are positioned on the mixing chamber 84 side by providing stepped portions 121, 124, 127 over the entire circumference in the middle of the length direction (injection direction of the mixed fluid). Small-diameter first ejection holes 122, 125, and 128 and large-diameter second ejection holes 123, 126, and 129 that are located on the front end side that open to the outside are formed.

  Therefore, as shown in FIGS. 5 and 6, the fuel compartment 53 ejects primary air from the fuel air nozzle 56 and the fuel auxiliary air nozzles 57 and 58 into the furnace 11 at a high speed, and each auxiliary air compartment. 54 and 55 eject secondary air from the auxiliary air nozzles 61 and 62 into the furnace 11 at a high speed. On the other hand, the burner gun 59 sprays a mixed fluid of fuel and steam from the burner tip 111 onto the furnace 11 to form a flame.

  At this time, as shown in FIGS. 8 and 9, in the burner tip 111, the mixed fluid ejection holes 112 at the uppermost part and the lowermost part eject the mixed fluid toward the outermost side, and the mixed fluid ejection near the axial center O1. The hole 114 ejects the mixed fluid toward the innermost side. That is, as shown in FIGS. 5 and 6, in the combustion burner 21, a fuel compartment 53 is disposed at an intermediate portion in the vertical direction, and auxiliary air compartments 54 and 55 are disposed above and below the combustion compartment 53. Therefore, as shown in FIGS. 8 and 9, the burner tip 111 is disposed at the center of the fuel compartment 53, so that the auxiliary air compartments 54, 55 from which auxiliary air is ejected from the mixed fluid ejection hole 112. By mixing the fluid mixture to the side, that is, the upper side and the lower side, mixing of fuel and air is promoted. On the other hand, since the auxiliary air compartment is not disposed on the side of the fuel compartment 53, the combustion burner 21 ejects the mixed fluid from the mixed fluid ejection holes 112, 113, 114 to the axis O1 side, Air mixing is promoted.

  In the burner tip 111, as shown in FIGS. 8 and 9, steam is supplied to the mixing chamber 84 along the direction of the axis O1 through the plurality of steam supply passages 87, and the fuel is supplied to the plurality of fuel supply passages. 88, is supplied from the outside along the radial direction to the mixing chamber 84 through the ejection chamber 85 and the communication passage 86. Then, in the mixing chamber 84, the fuel supplied from the outside along the radial direction collides with the vapor supplied along the direction of the axis O1, collides with each other, and is mixed.

  The mixed fluid efficiently mixed in the mixing chamber 84 flows forward through the mixing chamber 84 and is ejected (sprayed) to the outside through the mixed fluid ejection holes 112, 113, and 114. At this time, the mixed fluid is ejected from the first ejection holes 122, 125, 128 to the outside through the second ejection holes 123, 126, 129 via the stepped portions 121, 124, 127. Therefore, when the mixed fluid passes through the stepped portions 121, 124, and 127, the mixed fluid receives a shearing force, and the mixed fluid removes the fuel liquid film formed on the inner surfaces of the mixed fluid ejection holes 112, 113, and 114. Or it will be ejected outside at high speed without adhering to the inner surface, and the spray particle size of the fluid fuel can be reduced.

  As described above, in the burner tip and the combustion burner according to the third embodiment, a plurality of mixed fluid ejection holes whose base end portion communicates with the mixing chamber 84 and whose distal end portion opens and are arranged at predetermined intervals in the circumferential direction. 112, 113, 114 and stepped portions 121, 124, 127 provided in the mixed fluid ejection holes 112, 113, 114 to expand the passage area are provided, and the mixed fluid ejection at the top and bottom in the vertical direction is provided. Mixed fluid ejection holes 113 and 114 located between the hole 112 and the hole 112 are arranged on the axis O1 side.

  Therefore, when the mixed fluid passes through the mixed fluid ejection holes 112, 113, 114, the fuel liquid film formed on the inner surface is removed by the shearing force by the stepped portions 121, 124, 127, and is ejected to the outside at a high speed. The As a result, by promoting the mixing of fuel and steam, the spray particle size of the fuel can be reduced and the combustibility can be improved. In addition, it is possible to improve the combustibility by promoting the mixing of the liquid fuel in the mixed fluid ejected from the mixed fluid ejection holes 112, 113 and 114 and the surrounding air (primary air and secondary air).

  In the burner tip of the second embodiment, the plurality of mixed fluid ejection holes 112, 113, 114 are formed radially around a point O2 on the axis O1. Therefore, the workability of the plurality of mixed fluid ejection holes 112, 113, 114 can be improved and the manufacturing cost can be reduced.

  In the above-described embodiment, one stepped portion is provided in the mixed fluid ejection hole, but two or more stepped portions may be provided. Moreover, although the stepped part is provided in the middle part of the mixed fluid ejection hole, it may be provided on the mixing chamber side or the tip side.

  In the above-described embodiment, ten mixed fluid ejection holes are provided at the tip of the spray plate. However, the number and position are not limited to each embodiment. For example, a plurality of mixed fluid ejections are provided. You may provide a hole along a radial direction while providing a hole along the circumferential direction.

DESCRIPTION OF SYMBOLS 10 Oil fired boiler 11 Furnace 12 Combustion device 21 Combustion burner 22 Fuel supply piping 25 Steam supply piping 28 Air box 53 Fuel compartment 54 Upper auxiliary air compartment 55 Lower auxiliary air compartment 59 Burner gun 71, 101, 111 Burner tip 72 Spray plate (chip) Body)
73 Back plate (chip body)
82, 112, 113, 114 Mixed fluid ejection holes 84 Mixing chamber 85 Ejection chamber 86 Communication path 87 Steam supply path (spray medium supply path)
88 Fuel supply passage (fluid fuel supply passage)
91, 121, 124, 127 Stepped portion 92, 122, 125, 128 First ejection hole 93, 123, 126, 129 Second ejection hole

Claims (8)

A chip body;
A mixing chamber provided inside the chip body;
A plurality of mixed fluid ejection holes whose base end portion communicates with the mixing chamber and whose distal end portion opens at the distal end of the chip body and is arranged at predetermined intervals in the circumferential direction of the chip body;
A stepped portion that is provided in the mixed fluid ejection hole and expands a passage area;
A fluid fuel supply passage for supplying fluid fuel to the mixing chamber;
A spray medium supply passage for supplying the spray medium to the mixing chamber;
A burner tip characterized by comprising:   The mixed fluid ejection hole has a circular passage shape, and the stepped portion is provided on the entire circumference, so that the first ejection hole with a small diameter located on the mixing chamber side and the tip side of the chip body are positioned. The burner tip according to claim 1, wherein a large-diameter second ejection hole is provided.   A plurality of the spray medium supply passages are provided on the base end side of the tip body, and the spray medium can be supplied to the mixing chamber along the axial direction. The fluid fuel supply passage is the base end of the tip body. 3. The burner tip according to claim 1, wherein a plurality of the fuel burners are provided outside the spray medium supply passage on the side and fluid fuel can be supplied to the mixing chamber along a radial direction. 4.   The mixed fluid ejection hole between the uppermost portion and the lowermost portion of the tip body in the vertical direction is on the axial center side with respect to the mixed fluid ejection holes in the uppermost portion and the lowermost portion of the tip body in the vertical direction. The burner tip according to any one of claims 1 to 3, wherein the burner tip is arranged.   5. The burner tip according to claim 1, wherein the plurality of mixed fluid ejection holes are formed radially around one point on an axis of the tip body. 6. .   The tip body is configured by connecting a spray plate in which the mixed fluid ejection hole is formed and a back plate in which the fluid fuel supply passage and the spray medium supply passage are formed, and the spray plate and the back plate The burner tip according to any one of claims 1 to 5, wherein the mixing chamber is partitioned by the flow chamber and a part of the fluid fuel supply passage is partitioned. With a wind box,
A fuel compartment disposed in a central portion in a vertical direction in the wind box;
A burner gun disposed in the center of the fuel compartment;
A pair of upper and lower auxiliary air compartments arranged at the upper and lower parts in the vertical direction in the wind box;
Have
A combustion burner, wherein the burner tip according to any one of claims 1 to 6 is disposed at a tip portion of the burner gun. In a boiler that burns fuel and air in a hollow furnace and collects heat by exchanging heat in the furnace,
A combustion burner according to claim 7 is disposed on a furnace wall.

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