JP4383364B2 - Mixed burner - Google Patents

Description

  The present invention relates to a mixed combustion burner, in particular, a gas combustion fuel such as natural gas, a liquid fuel such as heavy oil, or a mixed combustion burner for a boiler in which a gas fuel and a liquid fuel are burned simultaneously, A steam spray type oil burner is placed in the center, a flame-holding swirler is placed around the tip, a part of the gas fuel is supplied into the flame-holding swirler, and the remaining gas fuel is supplied around the swirler. The present invention relates to a co-burning burner which is supplied from a main gas nozzle arranged outside to form a more stable and compact flame at the time of co-firing gas fuel and gas / liquid fuel.

Conventionally, gas flames are stabilized in a mixed-burning burner employed in an industrial or marine boiler in which gas fuel such as natural gas, liquid fuel such as heavy oil, or gas fuel and liquid fuel are burned simultaneously. Therefore, as shown in FIG. 4, there has been proposed a mixed combustion burner in which a flame holding flame is formed in the negative pressure region in the central part of the vortex caused by entrainment from the outside of the swirler, and the flame is held by the flame.
By the way, this mixed-burning burner has a flame holding swirler in the center of the burner, an oil atomizer is installed in the center, and a plurality of gas nozzles are installed in the outer periphery of the flame holding swirler. The gas is introduced from the gas supply port and guided to the gas chamber, and then ejected from each gas nozzle. The air is introduced into the wind box and then guided to the furnace through the inside of the register. At this time, a part of the air passes through the flame-holding swirler, a vortex having a negative pressure region is formed at the center, and a part of the gas ejected from the gas nozzle is led to the negative pressure region, and in the vicinity of the swirler. A stable flame with a flame holding effect is formed.

  By the way, in a mixed-burning burner, if a flame holding flame with a stable and optimum strength is not formed, it is particularly necessary for equipment operating at a high combustion chamber load or equipment having a rapid load fluctuation such as a boiler. The stability of flame formation and the compactness of the flame are lost, and vibration combustion, incomplete combustion, etc. are likely to occur.

  For this reason, in the mixed combustion burner as shown in FIG. 4, flame holding is performed by entrainment of gas from the outside of the swirler, so it is difficult to arbitrarily change the amount of flame holding gas. It was difficult to freely form a flame-holding flame having an arbitrary strength in the negative pressure region without breaking the negative pressure region.

  In view of the above-described problems of the conventional mixed-burning burner, the present invention provides a mixed-burning burner that can realize stable formation of a flame and can sufficiently cope with downsizing of a boiler. Objective.

  In order to achieve the above object, a burner for mixed combustion according to the present invention comprises an oil burner having an oil atomizer attached to the tip and disposed in the center of the register of the burner, and an oil burner on the outer periphery around the tip of the oil burner. In the mixed burner comprising a swirler disposed concentrically with respect to the oil burner and a plurality of gas burners disposed concentrically with respect to the oil burner, the gas burner is connected to the main gas burner and the pilot. The gas burner is separated from the main gas burner, and the pilot gas burner is disposed so as to penetrate the swirler. The gas jet direction from the pilot gas burner indicates the direction of the air blown by the swirler. With respect to the tangential direction of the virtual arrangement circle of the pilot gas burner arranged in the same direction as the turning direction and annularly spaced, Characterized in that the center side of the Sohai 設円 was set to be 0 ° to 60 ° angle range.

In this case, the gas ejection direction from the main gas burner is directed toward the burner tip in the same direction as the outer circumferential direction of the virtual arrangement circle of the main gas burner arranged annularly and the swirling direction of the air by the swirler. Can be set to spout.

Further, the direction of gas ejection from the main gas burner is set to the outer peripheral direction of the virtual arrangement circle of the main gas burner arranged annularly at intervals, the same direction as the swirling direction of the air by the swirler, and the intermediate direction between these directions. Can be set to spout toward

Furthermore , the gas supply amount from the pilot gas burner can be set to 10% to 55% of the total supply gas amount.

  According to the burner for mixed combustion of the present invention, an oil burner is attached to the tip of the oil atomizer and disposed at the center of the register of the burner, and an outer peripheral portion around the tip of the oil burner is concentric with the oil burner. And a plurality of gas burners arranged in a ring-shaped manner along the circumferential direction of the swirler, that is, concentrically with the oil burner and spaced annularly. In the burner, the gas burner is separated into the main gas burner and the pilot gas burner, the main gas burner is arranged on the outer periphery of the swirler, and the pilot gas burner is arranged so as to penetrate the swirler, so that the maintenance center set at the burner axis is set. Supply an appropriate amount of gas from the pilot gas burner at the position penetrating the swirler from the upstream side of the swirler to the negative pressure region formed by the flame swirler A more stable flame can be formed, and by providing an oil atomizer set on the central axis, oil-only firing, gas-only firing and oil-gas mixed firing are possible, and stable and compact flame formation is possible. Can be.

  In addition, by setting the gas supply amount from the pilot gas burner to 10% to 55% of the total supply gas amount, a flame accompanied by recirculation is formed by a swirler at the center of the burner, and the flame vortex causes main flow. The fuel ejected from the nozzle can be stably and continuously burned.

  In particular, in the mixed combustion burner of the present invention, the gas ejection direction from the pilot gas burner is set to −60 ° to 0 ° with respect to the tangential direction of the swirl circle substantially perpendicular to the axial direction, , In the same direction as the swirling direction of air by the swirler and in the center side of the imaginary arrangement circle with respect to the tangential direction of the imaginary arrangement circle of the pilot gas burner arranged annularly, By setting the angle range to °, the air vortex flow formed by the flame-holding swirler can be introduced without breaking, and a stable flame-holding flame can be formed. .

  In addition, the gas ejection direction from the main gas burner is set so as to eject in the outer circumferential direction and the turning direction, that is, the gas ejection direction from the main gas burner is virtually arranged in an annularly spaced manner. By setting to blow toward the tip side of the burner in the same direction as the outer circumference direction of the installation circle and the swirling direction of the air by the swirler, without destroying the flow of the air vortex formed by the flame holding swirler Mixing of air and gaseous fuel can be promoted.

  In addition, the gas ejection direction from the main gas burner is set so as to be ejected in the outer circumferential direction, the substantially swiveling direction, and the intermediate direction between them, that is, the gas ejection direction from the main gas burner is annularly spaced. It is formed with a flame-holding swirler by setting it to blow toward the tip side of the burner in the outer circumferential direction of the virtual arrangement circle of the main gas burner, the same direction as the air swirling direction by the swirler, and the intermediate direction between them The mixing of air and gaseous fuel can be further promoted without breaking the air vortex flow.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the co-burning burner of the present invention will be described below based on examples shown in the drawings.

1 to 3 show an embodiment of a mixed burner according to the present invention.
The oil and gas co-firing burner capable of forming a stable and compact flame is not particularly limited. For example, the co-firing burner B having the configuration shown in FIG. 1 can be used.

This mixed combustion burner B is a single oil burner 1 mainly using liquid fuel such as heavy oil, which is disposed in the central part of the mixed combustion burner B (which also serves as the central part of the register), like the conventional type burner. A flame holding swirler 3 concentrically disposed on the outer periphery of the oil burner 1 at the periphery of the oil burner 1, and a plurality of lines arranged in a dotted line along the circumferential direction of the swirler 3. The main gas burner 2 and the pilot gas burner 4 of the spoke type fuel gas burner.
In this case, the gas nozzles 2A and 4A are respectively attached to the front ends of the main gas burners 2 and the pilot gas burner 4, and are arranged in a ring-shaped manner, that is, concentrically with the oil burner and spaced in an annular manner. As shown in FIG. 2, the plurality of main gas burners 2 and pilot gas burners 4 are concentrically different in diameter with the main gas burner 2 having a large diameter and the pilot gas burner 4 having a small diameter, with the oil burner 1 as the center. Shall be placed.

  An oil atomizer 1A is attached to the distal end portion of the oil burner 1 in the same manner as a conventional oil burner, and oil supply for supplying heavy oil as fuel oil and steam as a spraying medium to the base end side of the oil burner 1 An outlet 1BO and a steam supply port 1BS are provided, and a flame-holding swirler 3 is provided at the outer periphery of the oil burner 1 so as to surround the outer periphery of the oil atomizer 1A. The hopper 5 is attached to the peripheral side.

  A gas chamber 6 is disposed on the base end side of the main gas burner 2 and the pilot gas burner 4 so as to connect all the main gas burners 2 and the pilot gas burner 4, and is supplied from a gas supply port 2B connected to the gas chamber 6. A fuel gas such as natural gas is supplied to all the gas burners 2 and 4 through the gas chamber 6 and ejected from the pilot gas nozzle 4A and the main gas nozzle 2A.

In addition, the oil burner 1 disposed in the center and the plurality of main gas burners 2 and pilot gas burners 4 disposed on the outer periphery of the oil burner 1 are accommodated in one register 7, and the register 7 is disposed in the wind box 8, The air blower sent from the blower (not shown) into the wind box 8 is introduced into the register through the air supply port 8B of the register 8, and the burner tile is arranged so as to surround the outer periphery of the register 7 through the tip of the register 7. 9 is configured to flow into.
In addition, 8A in the figure is an air distribution plate for preventing the flow drift, and the inside of the register having a cylindrical shape and a tip-end shape is formed by adjusting the flow of air introduced from the air supply port 8B into the register. To circulate. Reference numeral 10 denotes a burner front plate.

Further, as shown in FIG. 1B and FIG. 2, the number of main gas burners 2 arranged in an annular broken line so as to surround the swirler 3 arranged on the outer periphery of the tip end of the oil burner 1 in the outer periphery of the oil burner 1. The number varies depending on the burner capacity and is not particularly limited. For example, the number is about 3 to 10 (in this embodiment, 5).
As shown in FIG. 2, the main gas nozzles 2A attached to the tips of the main gas burners 2 are arranged in the outer circumferential direction (substantially in the radial direction, that is, annularly spaced) for each main gas nozzle 2A. About 1 to 5 (in this embodiment, 1) gas ejection holes 11a and air swirl direction (substantially round) so that the main gas burner 2 is jetted toward the front end side in the virtual arrangement circle of the main gas burner 2 About 1 to 5 (one in this embodiment) gas ejection holes 11b are provided so as to inject toward the tip in the direction, that is, the same direction as the air swirl direction by the swirler 3. .
The configuration of the main gas nozzle 2A is not limited to this. For example, as shown in FIG. 3, each main gas nozzle 2A is disposed in the outer circumferential direction (substantially in the radial direction, that is, annularly spaced). About 1 to 5 (in this embodiment, 1) gas ejection holes 11a and air swirl direction (substantially round) so that the main gas burner 2 is jetted toward the front end side in the virtual arrangement circle of the main gas burner 2 About 1 to 5 (one in this embodiment) gas ejection holes 11b and the tip in the middle so as to inject toward the tip side in the direction, that is, the same direction as the air swirl direction by the swirler 3 About 1 to 5 (one in this embodiment) gas ejection holes 11c may be provided so as to inject toward the side.
As a result, the gas ejection direction from the main gas nozzle 2A becomes the outer circumferential direction and the swirl direction. When the gas flows evenly through the register and passes through the swirler 3, the air is moved to the right or left by the swirl vanes of the swirler 3 Since the swirl in the direction is applied and the swirler 3 also acts on the air at the outer peripheral portion of the swirler 3 and swirls, the mixing of the gaseous fuel ejected from the main gas nozzle 2A in the outer peripheral direction and the swirling direction is promoted. .

The pilot gas burner 4 is changed according to the burner capacity in the same manner as the main gas burner 2 and is not particularly limited. For example, the pilot gas burner 4 is a plurality of about 3 to 10 (5 in this embodiment). The pilot gas nozzle 4A attached to the tip of each pilot gas burner 4 has a gas ejection direction with respect to a tangential direction of a swirl circle (a swirl direction by the flame-holding swirler 3) substantially perpendicular to the burner axial direction. -60 ° to 0 ° (−36 ° in the present embodiment), that is, the virtual direction of the pilot gas burner 4 disposed in the same direction as the swirling direction of the air by the swirler 3 and spaced annularly. The gas ejection holes 11d are provided so as to have an angle range of 0 ° to 60 ° on the center side of the virtual arrangement circle with respect to the tangential direction of the arrangement circle.
As a result, gas can be introduced without breaking the air vortex flow formed by the flame-holding swirler 3, and a stable flame-holding flame can be formed.
Further, the gas supply amount from the pilot gas burner is set to 10% to 55% of the total supply gas amount. This gas supply amount can be freely adjusted within a range of 10% to 55%.

Next, the operation of this mixed burner will be described with reference to the drawings.
When heavy oil as fuel oil having a predetermined hydraulic pressure and spraying steam as a spraying medium are supplied to the oil supply port 1BO and the steam supply port 1BS of the oil burner 1, the oil burner 1 It mixes in the oil atomizer 1A attached to the front-end | tip through the inside, becomes a spray form, and is discharged in the spray form into the combustion chamber in the burner tile 9.

  On the other hand, when the combustion air is fed into the wind box 8 from the blower or the like through the air supply port 8B so as to prevent the flow drift in the air distribution flow plate 8A, the combustion air is disposed in the wind box 8. Then, the gas flows into the burner tile 9 arranged so as to surround the outer periphery of the tip of the register 7 through the tip of the register 7. At this time, a part of the air flowing in the register 7 is formed with a vortex having a negative pressure region at the center through the flame-holding swirler 3, and the remaining part is formed in the clearance around the outer periphery of the flame-holding swirler. Supplied into a flow furnace.

Gas body fuel such as natural gas is supplied into the gas chamber 6 from the gas supply port 2B, supplied to the plurality of in-gas burners 2 and the pilot gas burner 4 connected to the gas chamber 6, and attached to the tip. The main gas nozzle 2A and the pilot gas nozzle 4A are ejected.
The amount of gas ejected from the pilot gas nozzle 4A can be arbitrarily determined, and is not particularly limited, and varies depending on the size of the flame-holding swirler. It is optimal to be about ~ 55%.
Thus, 10% to 55% of the gaseous fuel is supplied to the negative pressure region formed by the swirler in the burner center, and the remaining gas fuel is supplied from the main gas nozzle and burned, thereby burning the burner center. The swirler can form a flame with recirculation, and the fuel ejected from the main gas nozzle can be stably and continuously burned by the vortex of the flame.

  If the gas fuel (pilot gas amount) supplied to the center of this burner is less than 10% of the total supply gas amount, the flame holding flame will not be stable and the required flame holding power will be secured. In addition, the entire flame becomes unstable and it becomes difficult to obtain a stable flame. On the contrary, the gas body fuel (amount of pilot gas) supplied to the swirl formed by the swirler at the center of the burner is fully supplied. When the amount of gas is more than 55%, the negative pressure region in the central part becomes weak, the entire flame becomes unstable, the air in the central part becomes short and a long flame is formed, and the compactness of the flame is lost.

  In this case, the jet direction of the pilot gas jetted from the pilot gas nozzle 4A is set in a range of −60 ° to 0 ° with respect to the tangential direction of the swirling of the flame-holding swirler. Therefore, since the vortex flow formed by the flame holding swirler is not broken, a stable flame holding flame is formed.

  Further, by providing an oil atomizer at the tip of the oil burner which is the center of the burner, it can be used as an oil-only burner or an oil / gas mixed burner capable of simultaneously burning oil and gas. In this case, the oil flame is sufficiently held in the negative pressure region formed by the flame holding swirler, and a stable flame is formed. Accordingly, it is possible to operate the oil and gas fuel with a high burn-up ratio from the exclusive combustion operation of each fuel to the mixed combustion of both fuels with the same burner, and to form a compact and stable flame.

  As mentioned above, although the mixed burner of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, The structure is suitably changed in the range which does not deviate from the meaning. It is something that can be done.

  The burner for mixed combustion of the present invention forms a flame accompanied by recirculation by a swirler at the center of the burner, and stably burns the fuel ejected from the main gas nozzle by the vortex of the flame, thereby stabilizing the flame. Therefore, it can be suitably used for industrial or marine boiler applications.

An example of the burner for mixed combustion of this invention is shown, (A) is sectional drawing, (B) is a front view. It is the same enlarged front view. The modification example of the burner for mixed combustion of this invention is shown, (a) is an enlarged front view of the burner for mixed combustion, (b) is a front view of the main gas nozzle, (c) is a sectional view of the main gas nozzle, (d) is a pilot The front view of the gas nozzle for operation, (e) is a sectional view of the gas nozzle for pilot. It is sectional drawing of the conventional burner.

B Burner for mixed combustion 1 Oil burner 1A Oil atomizer 1BO Oil supply port 1BS Steam supply port 2 Main gas burner 2A Main gas nozzle 2B Gas supply port 3 Swirler 4 Pilot gas burner 4A Pilot gas nozzle 5 Damper 6 Gas chamber 7 Register 8 Air box 8A Supply port 9 Burner tile 10 Burner front plate 11a Gas ejection hole 11b Gas ejection hole 11c Gas ejection hole 11d Gas ejection hole

Claims (4)

  An oil burner attached to the tip of an oil atomizer and disposed in the center of the register of the burner, a swirler disposed concentrically with respect to the oil burner on the outer periphery around the tip of the oil burner, and the oil burner The gas burner is divided into a main gas burner and a pilot gas burner, and the main gas burner is arranged on the outer periphery of the swirler. , A mixed-burning burner in which pilot gas burners are respectively arranged so as to penetrate the swirler, and the gas ejection direction from the pilot gas burner is the same direction as the air swirling direction by the swirler, and is annularly spaced With respect to the tangential direction of the imaginary arrangement circle of the arranged pilot gas burner, the angle range is 0 ° to 60 ° on the center side of the imaginary arrangement circle. Multi-fuel burner, characterized in that the sea urchin set. The gas ejection direction from the main gas burners, so as to eject toward the front end side of the burner in the turning direction in the same direction of the air by the outer circumferential direction and swirler virtual distribution設円main gas burner which is disposed at intervals in the annular The mixed-burning burner according to claim 1, wherein The gas ejection direction from the main gas burners, the outer peripheral direction of the virtual distribution設円main gas burner which is disposed at intervals in the annular distal end side of the burner in the turning direction in the same direction and these intermediate direction of the air by swirler The mixed-burning burner according to claim 1 , wherein the burner is set so as to be jetted out.   4. The mixed combustion burner according to claim 1, wherein the gas supply amount from the pilot gas burner is set to 10% to 55% of the total supply gas amount.

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