JP2008209062A - Combustion burner, boiler and combustion method of dust coal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion burner, a boiler and a combustion method of dust coal, capable of preventing sedimentation of the dust coal and a backfire with a simple structure, by reducing an unburnt loss in fine powder fuel, by preventing a variation in a secondary air flow rate by a tilting change in a dust coal nozzle. <P>SOLUTION: This combustion burner 10A on a first embodiment by this invention has a dust coal nozzle pipe 13 feeding carrying primary air 12 including the dust coal 11 to an unillustrated furnace, a secondary air nozzle pipe 15 feeding heated combustion secondary air 14 to the furnace, and a fuel nozzle 19 rockably arranged in the vicinity of a tip part of the dust coal nozzle pipe 13 and having a primary air passage 16 for flowing the primary air 12. The combustion burner has an air flow rate adjusting plate 23 arranged in the secondary air nozzle pipe 15, and grounded on an outer wall of a fuel nozzle 19, and driven by the vertical movement as the fuel nozzle 19 turns an angle α upward. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a combustion burner, a boiler, and a method for burning pulverized coal suitable for application to various combustion apparatuses such as a pulverized coal fired boiler and a petroleum coke fired boiler that generate steam for power generation or industrial use.

  Conventionally, a technology that mixes gas and liquid has been used in combustion burners, etc., where fuel oil derived from different systems is mixed with gas such as air and ejected from the tip in a mixed state. To do. The jetted fuel oil is atomized in the jet and atomized, burned by ignition, and good combustion can be performed by making the spray state after jetting good (Patent Documents 1 and 2). .

An example of the configuration of a conventional combustion burner is shown in FIGS. FIG. 8 is a schematic diagram showing an example of the configuration of the tip of a conventional burner, and is a diagram when the burner angle is in a base state of 0 °. FIG. 9 is a view showing a state when a conventional burner is tilted upward. As shown in FIGS. 8 and 9, a conventional combustion burner 100 includes a pulverized coal nozzle pipe 13 that feeds primary air 12 for transportation containing pulverized coal 11 to a furnace (not shown), and a heated combustion burner 100. A secondary air nozzle pipe 15 for feeding the secondary air 14 to the furnace and a primary air passage 16 that is swingably disposed near the tip of the pulverized coal nozzle pipe 13 and through which the primary air 12 flows. The fuel nozzle 19 is provided.
The fuel nozzle 19 is provided around a pulverized coal nozzle 19a having a primary air passage 16 through which the primary air 12 circulates, and around the pulverized coal nozzle 19a. This is a double pipe structure comprising a secondary air nozzle 19b having a secondary air passage 18 through which a certain mainstream secondary air 17 flows.

  In the combustion burner 100 </ b> A, the primary air 12 having a temperature of about 80 ° C. flows through the primary air passage 16 in the center and is supplied from the secondary air nozzle pipe 15 to the one of the secondary air 14 having a temperature of about 300 to 350 ° C. The mainstream secondary air 17 that is a part circulates in the secondary air passage 18. Further, nozzle cooling air 20 that is a part of the secondary air 14 circulates around the outer periphery of the pulverized coal nozzle 19a. Further, in some cases, the tertiary air 21 is also circulated through the tertiary air nozzle 22 as additional air of about 300 to 350 ° C. on the outer peripheral portion or the upper and lower sides, and in a plurality of stages in the vertical direction on the furnace wall (not shown). Has been placed.

  In the conventional combustion burner 100, the steam temperature and exhaust gas characteristics are controlled by tilting the pulverized coal nozzle 19a up and down. For example, as shown in FIG. 8, when the angle of the pulverized coal nozzle 19a is tilted upward, the angle of the pulverized coal nozzle 19a is adjusted so that the pulverized coal nozzle 19a faces upward, and the secondary air nozzle tube 15 The nozzle cooling air 20 is fed from the upper and lower gaps of the secondary air nozzle 19b to enhance the cooling effect of the pulverized coal nozzle 19a.

JP-A-10-332110 US Pat. No. 6,260,491

  However, as shown in FIG. 9, for example, when the conventional combustion burner 100 tilts upward at an angle α of the pulverized coal nozzle 19a, a space between the secondary air nozzle 19b and the secondary air nozzle pipe 15 is used. And the flow rate of the secondary air 14 for maintaining the cooling effect of the pulverized coal nozzle 19a cannot be optimized. There is.

  For example, in the secondary air 14, the ratio of the nozzle cooling air 20 to the mainstream secondary air 17 is approximately a ratio of about 3 to 7, but the ratio is increased by increasing the angle of the pulverized coal nozzle 19 a. And the primary air 12 flows backward to the secondary air nozzle tube 15 side due to a decrease in the flow rate of the main flow secondary air 17, and the pulverized coal 11 in the primary air 12 may cause the drawing of flame. There is a problem that there is.

Further, since the nozzle cooling air 20 is introduced from the periphery of the pulverized coal nozzle 19a,
There is a problem that the nozzle cooling air 20 is supplied excessively and the unburned portion of the pulverized coal 11 is increased by not supplying the main flow secondary air 17 suitable for burning the pulverized fuel.

  In view of the above problems, the present invention prevents the fluctuation of the secondary air flow rate due to the tilting change of the pulverized coal nozzle, reduces unburned loss of the pulverized fuel, and prevents pulverized coal accumulation and backfire with a simple structure. It is an object to provide a combustion method of a combustion burner, a boiler, and pulverized coal that can be made possible.

  1st invention of this invention for solving the subject mentioned above is the pulverized coal nozzle pipe | tube which supplies the primary air for conveyance containing pulverized coal to a furnace, and the heated secondary air for combustion is said In a combustion burner having a secondary air nozzle pipe to be fed to a furnace, a fuel nozzle having a primary air passage through which the primary air is circulated and arranged in the vicinity of the tip of the pulverized coal nozzle pipe, The combustion burner is provided with a secondary air nozzle pipe, is in contact with an outer wall of the fuel nozzle, and has an air flow rate adjusting plate that is moved up and down as the fuel nozzle tilts.

  According to a second invention, in the first invention, the fuel nozzle is provided around a pulverized coal nozzle having a primary air passage through which the primary air flows, and a part of the secondary air. The combustion burner is characterized by having a double-pipe structure comprising a secondary air nozzle having a secondary air passage through which the gas flows.

  A third invention is the first or second invention, wherein the air flow rate adjusting plate is provided integrally or separately from the outer wall of the pulverized coal nozzle and is moved up and down as the pulverized coal nozzle tilts. And a combustion burner having a roller for moving the air flow rate adjusting plate up and down.

  According to a fourth aspect of the present invention, there is provided a boiler comprising the combustion burner according to any one of the first to third aspects.

  According to a fifth aspect of the present invention, there is provided a pulverized coal nozzle tube for supplying primary air for conveyance containing pulverized coal to a furnace, and a secondary air nozzle tube for supplying heated secondary air for combustion to the furnace. In the method for burning pulverized coal, the pulverized coal nozzle pipe is provided in the secondary air nozzle pipe in a combustion method of a pulverized coal having a fuel nozzle having a primary air passage through which the primary air flows. An air flow rate adjusting plate is grounded to the outer wall of the fuel nozzle, and as the fuel nozzle is tilted, the air flow rate adjusting plate is moved up and down, and the secondary air nozzle pipe and the fuel nozzle are changed by tilting of the fuel nozzle. A method for combusting pulverized coal, in which a flow area of cooling air that is a part of the secondary air flowing between the cooling air and the flow rate of the cooling air is prevented. .

  According to a sixth invention, in the fifth invention, the fuel nozzle is provided around a pulverized coal nozzle having a primary air passage through which the primary air flows, and a part of the secondary air. It is in the combustion method of pulverized coal characterized by having a double-pipe structure comprising a secondary air nozzle having a secondary air passage through which the gas flows.

  A seventh invention is the fifth or sixth invention, wherein the air flow rate adjusting plate is provided integrally or separately from the outer wall of the pulverized coal nozzle, and is moved up and down as the pulverized coal nozzle tilts. And a pulverized coal combustion method comprising a roller for moving the air flow rate adjusting plate up and down.

  According to the present invention, a pulverized coal nozzle pipe is provided in the secondary air nozzle pipe for guiding heated secondary air for combustion to the burner, and feeds primary air for conveyance containing pulverized coal to a furnace. The secondary air nozzle tube with a simple structure that operates simultaneously with the tilting of the pulverized coal nozzle. The flow area of the secondary air flowing between the pulverized coal nozzle and the pulverized coal nozzle can be made constant, so that the change in the flow rate of the secondary air can be prevented and the unburned portion of the pulverized coal Loss can be reduced, and accumulation and backfire of the pulverized coal can be prevented.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[First embodiment]
A combustion burner according to a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a configuration of a combustion burner according to a first embodiment of the present invention, and is a diagram in a base state where the burner angle is 0 °. FIG. 2 is a view showing a state when the combustion burner according to the first embodiment of the present invention is tilted upward. The combustion burner according to the first embodiment of the present invention is substantially the same as the structure of the conventional combustion burner 100 shown in FIGS. 8 and 9, so the conventional combustion shown in FIGS. The same components as those of the burner 100 are denoted by the same reference numerals, and redundant description is omitted.
As shown in FIGS. 1 and 2, a combustion burner 10 </ b> A according to a first embodiment of the present invention is a pulverized coal nozzle tube that supplies primary air 12 for conveyance containing pulverized coal 11 to a furnace (not shown). 13, a secondary air nozzle pipe 15 that feeds heated secondary air 14 for combustion to the furnace, and a pulverized coal nozzle pipe 13 that is swingably disposed near the tip of the primary air. In the combustion burner having a fuel nozzle 19 having a primary air passage 16 through which the fuel gas 12 flows, provided in the secondary air nozzle pipe 15 and in contact with the outer wall of the fuel nozzle 19, the fuel nozzle 19 faces upward at an angle α. The air flow rate adjusting plate 23 that follows the up-and-down movement as it goes down is provided.

  In the first combustion burner 10A according to the present embodiment, the fuel nozzle 19 is provided around a pulverized coal nozzle 19a having a primary air passage 16 through which the primary air 12 flows, and the pulverized coal nozzle 19a. , A secondary pipe structure comprising a secondary air nozzle 19b having a secondary air passage 18 through which main flow secondary air 17 which is a part of the secondary air 14 circulates.

  The first combustion burner 10A according to the present embodiment includes the air flow rate adjusting plate 23 provided on the secondary air nozzle pipe 15 and in contact with the outer wall of the fuel nozzle 19. The secondary air nozzle pipe 15 and the secondary air nozzle 19b are caused by the tilting change of the pulverized coal nozzle 19a by causing the air flow rate adjusting plate 23 to move up and down as the pulverized coal nozzle 19a is directed upward at the angle α. The flow area of the nozzle cooling air 20, which is a part of the secondary air 14 flowing between the two, can be made constant.

  Thereby, while being able to set it as the flow volume of the said nozzle cooling air 20 required in order to maintain the cooling effect of the said pulverized coal nozzle 19a, it is set as the flow volume suitable for the said mainstream secondary air 17 to burn pulverized fuel. Therefore, the loss of the unburned portion of the pulverized coal 11 associated with the tilt change of the pulverized coal nozzle 19a can be reduced.

  Moreover, since the fluctuation | variation of the flow velocity of the said secondary air 14 sent from the said secondary air nozzle pipe | tube 15 can be prevented, the flow volume of the said main flow secondary air 17 is changed by the tilting change of the said pulverized coal nozzle 19a. It is possible to prevent the primary air 12 from flowing back to the secondary air nozzle pipe 15 and depositing the pulverized coal 11 and backfire by the pulverized coal 11 in the primary air 12.

  Further, the first combustion burner 10A according to the present embodiment can tilt the pulverized coal nozzle 19a because the pulverized coal nozzle 19a can move the air flow rate adjusting plate 23 up and down as the angle α is upward. Adjustment of the flow rate of the secondary air 14 accompanying the change can be performed with a simple configuration.

  Further, in the first combustion burner 10A according to the present embodiment, the air flow rate adjusting plate 23 may be provided with a space through which the nozzle cooling air 20 necessary for cooling flows. By ensuring a space through which the necessary flow rate of the nozzle cooling air 20 flows in the air flow rate adjusting plate 23, it is possible to always ensure a constant flow rate of the nozzle cooling air 20 even if the pulverized coal nozzle 19a is tilted and changed. it can.

  Further, in the first combustion burner 10A according to the present embodiment, since the air flow rate adjusting plate 23 is provided on the upper side of the secondary air nozzle pipe 15, the tilting change of the pulverized coal nozzle 19a is accompanied. In addition, the flow area of the nozzle cooling air 20 flowing between the secondary air nozzle pipe 15 and the secondary air nozzle 19b can be made constant. The distribution area of the nozzle cooling air 20 flowing between the provided tertiary air nozzle 22 and the secondary air nozzle pipe 15 can also be made constant. Therefore, the first combustion burner 10 </ b> A according to the present embodiment can adjust the flow rate of the nozzle cooling air 20 at two locations with the single air flow rate adjusting plate 23.

  In the first combustion burner 10 </ b> A according to the present embodiment, the air flow rate adjustment plate that slides the air flow rate adjustment plate 23 up and down between the air flow rate adjustment plate 23 and the secondary air nozzle tube 15. A guide 24 is provided. By providing a flow rate adjusting plate guide 24 between the air flow rate adjusting plate 23 and the secondary air nozzle tube 15, the air flow rate adjustment is performed between the air flow rate adjusting plate 23 and the secondary air nozzle tube 15. Without providing a member for restraining the plate 23, the air flow rate adjusting plate 23 can be slid up and down with a simple structure.

  Further, in the first combustion burner 10A according to the present embodiment, as the fuel nozzle 19, a double pipe structure composed of the pulverized coal nozzle 19a and the secondary air nozzle 19b is used. This invention is not limited to this, You may use what consists only of the said pulverized coal nozzle 19a.

  Thus, according to the first combustion burner 10A according to the present embodiment, the primary air nozzle pipe 15 that guides the heated secondary air 14 for combustion to the burner (not shown) is provided, and the primary The pulverized coal is provided with the air flow rate adjusting plate 23 that contacts the outer wall of the pulverized coal nozzle pipe 13 that guides the air 12 to a furnace (not shown) and that moves up and down as the pulverized coal nozzle 19a tilts. The flow area of the secondary air 14 flowing between the secondary air nozzle pipe 15 and the secondary air nozzle 19b is constant with a simple structure that operates simultaneously with the tilt of the nozzle 19a due to the tilt change of the pulverized coal nozzle 19a. Therefore, a change in the flow rate of the secondary air 14 can be prevented, and loss of unburned coal 11 can be reduced, and the pulverized coal 11 can be reduced. Deposited and reverse fire can be prevented.

[Second Embodiment]
A combustion burner according to a second embodiment of the present invention will be described with reference to the drawings.
FIG. 3 is a schematic diagram showing the configuration of a combustion burner 10B according to the second embodiment of the present invention. FIG. 4 is a view showing a state when the combustion burner according to the second embodiment of the present invention is tilted upward. FIG. 5 is a partially enlarged view of the combustion burner shown in FIGS. 3 and 4. 6 is a cross-sectional view in a direction perpendicular to the axis of the combustion burner shown in FIG.
The combustion burner 10B according to the second embodiment of the present invention is substantially the same as the configuration of the first combustion burner 10A according to the first embodiment shown in FIG. Further, the same components as those of the first combustion burner 10A according to the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
As shown in FIGS. 3 to 6, the second combustion burner 10B according to the present embodiment is provided separately at the lower part of the air flow rate adjusting plate 23 of the first combustion burner 10A shown in FIG. A roller 25 that is in contact with the outer wall of the secondary air nozzle 19b, is moved up and down as the pulverized coal nozzle 19a is turned upward at an angle α, and moves the air flow rate adjusting plate 23 up and down. It is.

  As in the second combustion burner 10B according to the present embodiment, by providing a roller 25 that contacts the outer wall of the secondary air nozzle 19b at the lower part of the air flow rate adjusting plate 23, the pulverized coal nozzle 19a has an angle. Since the roller 25 can be moved up and down and the air flow rate adjusting plate 23 can be moved up and down as α is directed upward, the malfunction of the air flow rate adjusting plate 23 caused by the tilting change of the pulverized coal nozzle 19a is prevented. Can be prevented.

  Further, in the second combustion burner 10B according to the present embodiment, a space through which the nozzle cooling air 20 necessary for cooling flows may be provided in the air flow rate adjusting plate 23. Further, a space in which the nozzle cooling air 20 necessary for cooling flows between the air flow rate adjusting plate 23 and the roller 25 as shown in FIG.

  A space through which the nozzle cooling air 20 necessary for cooling flows is provided in the air flow rate adjusting plate 23, and a space through which the necessary flow rate of the nozzle cooling air 20 flows is ensured between the air flow rate adjusting plate 23 and the roller 25. Thereby, even if the pulverized coal nozzle 19a is tilted and changed, the flow rate of the secondary air 14 flowing between the secondary air nozzle pipe 15 and the secondary air nozzle 19b can be always kept constant. Thereby, as the pulverized coal nozzle 19a tilts, the roller 25 can be moved up and down and the air flow rate adjusting plate 23 can be moved up and down, so that the air flow rate accompanying the tilt change of the pulverized coal nozzle 19a. A malfunction of the adjusting plate 23 can be prevented.

  Thus, according to the second combustion burner 10B according to the present embodiment, since the roller 25 that contacts the outer wall of the secondary air nozzle 19b is provided below the air flow rate adjusting plate 23, the fine powder The flow area of the secondary air 14 flowing between the secondary air nozzle pipe 15 and the secondary air nozzle 19b with a simple structure that operates simultaneously with the tilting of the charcoal nozzle 19a due to the tilting change of the pulverized coal nozzle 19a. In addition, the air flow rate adjusting plate 23 can be prevented from malfunctioning due to the tilt change of the pulverized coal nozzle 19a. Thereby, while being able to prevent the change of the flow volume of the said secondary air 14 accompanying the tilting change of the said pulverized coal nozzle 19a, the loss of the unburned part of the pulverized coal 11 can be reduced, the said pulverized coal 11 accumulation and flashback can be prevented.

  Further, in the second combustion burner 10B according to the present embodiment, the roller 25 is provided separately in the lower part of the air flow rate adjusting plate 23, but the present invention is not limited to this, The air flow rate adjusting plate 23 may be provided integrally.

  Moreover, in the 2nd combustion burner 10B which concerns on this Embodiment, it is not limited to the said roller 25, For example, what is necessary is just the member converted into rotational motions, such as a crank.

[Third embodiment]
A boiler according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 7 is a schematic view showing a configuration of a boiler according to the third embodiment of the present invention. The combustion burner 1009 used in the boiler according to the third embodiment of the present invention is duplicated because one of the first combustion burner 10A shown in FIG. 1 and the second combustion burner 10B shown in FIG. 3 is used. Description is omitted.
As shown in FIG. 7, a boiler 1000 according to a third embodiment of the present invention includes a furnace 1001 installed in a vertical direction, a combustion device 1003 installed below a furnace wall 1002 of the furnace 1001, A flue 1004 connected to the outlet of the furnace 1001, a superheater 1005 provided from the upper part of the furnace 1001 to the flue 1004, a reheater 1006 and a economizer 1007, and an upper part of the furnace 1001 And a steam drum (not shown).

A large number of water pipes (not shown) extend in the vertical direction inside the furnace wall 1002. Each water pipe is connected at its upper and lower ends to a steam drum (not shown).
The combustion apparatus 1003 includes a plurality of combustion burners 1009 attached to the furnace wall 1002, pulverized coal supply means 1010 for supplying pulverized coal 11 to the combustion burner 1009, and the combustion burner 1009 as the combustion air. And air supply means 1011 for supplying the secondary air 14.

  The pulverized coal supply means 1010 includes a pulverized coal machine 1012 that pulverizes coal supplied through a coal feeder and a meter (not shown) to a size suitable for combustion (for example, several μm to several hundred μm), and pulverized powder. A pulverized coal 11 generated by the charcoal machine 1012 is provided with a coal supply pipe 1013 that carries air flow to the combustion burner by primary air 12 that is pressurized carrier air supplied from an air source (not shown). The primary air 12 is set so that the outlet temperature of the pulverized coal machine 1012 is, for example, about 80 ° C. from the safety aspect of the pulverized coal machine 1012. The pulverized coal 11 generated by the pulverized coal machine 1012 is conveyed by the primary air 12 and sent to the combustion burner 1009 through the coal supply pipe 1013.

  The air supply means 1011 includes a forced air blower (not shown) that pressurizes and supplies air, a wind box 1014 provided on the outer wall of the furnace 1001, and a secondary air supply that connects the forced air fan and the wind box 1014. Tube 1015. The secondary air 14 pressurized and supplied by a not-shown forced air fan passes through the flue 1004 by the rotary regenerative heat exchanger 1017. For example, heat is exchanged with the combustion exhaust gas 1016 at about 360 ° C., and the temperature is raised to, for example, 300 to 350 ° C., supplied to the wind box 1014 through the secondary air supply pipe 1015, and sent to the combustion burner 1009.

  When the primary air 12 and the secondary air 14 are supplied from the combustion burner 1009 into the furnace 1001 and ignited, a flame is generated in the furnace.

  When a flame is generated in the lower part of the furnace 1001 in this way, the combustion gas flows from the bottom up in the furnace 1001 and is discharged to the flue 1004. At this time, water supplied from a water supply pump (not shown) is preheated by the economizer 1007 and then supplied to a steam drum (not shown). Water supplied from a steam drum (not shown) to each water pipe (not shown) of the furnace wall 1002 is heated while flowing from the bottom to the top to become saturated steam, and is sent to a steam drum (not shown). Further, saturated steam of a steam drum (not shown) is introduced into the superheater 1005 and is heated by the combustion gas. The superheated steam generated by the superheater 1005 is supplied to a predetermined plant (for example, a turbine or the like).

In addition, the steam taken out in the middle of the expansion process in the turbine is introduced into the reheater 1006, and is reheated and returned to the turbine.
The combustion exhaust gas 1016 that has passed through the economizer 1007 supplies heat to the secondary air 14 that has passed through the secondary air supply pipe 1015 in the rotary regenerative heat exchanger 1017 to desulfurize, denitrate, dust, etc. After being treated, it is discharged from the chimney into the atmosphere.

  As described above, according to the boiler according to the second embodiment of the present invention, any one of the first combustion burner 10A shown in FIG. 1 and the second combustion burner 10B shown in FIG. Therefore, even when the pulverized coal nozzle 19a is tilted, a change in the flow rate of the secondary air 14 can be prevented, loss of the unburned pulverized coal 11 can be reduced, Backfire can be prevented. Thereby, combustion efficiency can be improved.

  As described above, the combustion method of the combustion burner, boiler, and pulverized coal according to the present invention is in contact with the outer wall of the pulverized coal nozzle pipe that guides primary air containing pulverized coal to the burner, and moves up and down as the pulverized coal nozzle tilts. By providing the secondary air nozzle pipe with an air flow rate adjusting plate that follows the movement, the air flowing between the secondary air nozzle pipe and the pulverized coal nozzle with a simple structure that operates simultaneously with the tilting of the pulverized coal nozzle. Since the flow area of the secondary air can be made constant, the change in the flow rate of the secondary air can be prevented, and the loss of the unburned portion of the pulverized coal can be reduced. Suitable for prevention of flashback.

It is the schematic which shows the structure of the combustion burner which concerns on 1st embodiment by this invention, and is a figure at the time of the base state where the angle of a burner is 0 degree. It is a figure which shows a state when the combustion burner which concerns on 1st embodiment by this invention is made to tilt upward. It is the schematic which shows the structure of the combustion burner which concerns on 2nd embodiment by this invention. It is a figure which shows a state when the combustion burner which concerns on 2nd embodiment by this invention is made to tilt upward. It is the elements on larger scale of the combustion burner shown in FIG. 3, FIG. It is sectional drawing of the direction orthogonal to the axis | shaft of the combustion burner shown in FIG. It is the schematic which shows the structure of the boiler which concerns on 2nd embodiment of this invention. It is the schematic which shows an example of a structure of the front-end | tip of the conventional burner, and is a figure at the time of the base state where the angle of a burner is 0 degree. It is a figure which shows a state when the conventional burner is made to tilt upward.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10A 1st combustion burner 10B 2nd combustion burner 11 Pulverized coal 12 Primary air 13 Pulverized coal nozzle pipe 14 Secondary air 15 Secondary air nozzle pipe 16 Primary air passage 17 Main flow secondary air 18 Secondary air passage 19 Fuel nozzle 19a pulverized coal nozzle 19b secondary air nozzle 20 nozzle cooling air 21 tertiary air 22 tertiary air nozzle 23 air flow rate adjusting plate 24 flow rate adjusting plate guide 25 roller α angle 1000 boiler 1001 furnace 1002 furnace wall 1003 combustion device 1004 flue 1005 superheater 1006 reheater 1007 economizer 1009 combustion burner 1010 pulverized coal supply means 1011 air supply means 1012 pulverized coal machine 1013 coal supply pipe 1014 wind box 1015 secondary air supply pipe 1016 combustion exhaust gas 1017 rotation regenerative heat exchanger

Claims (7)

A pulverized coal nozzle pipe for supplying primary air for conveyance containing pulverized coal to a furnace;
A secondary air nozzle tube for supplying heated secondary air for combustion to the furnace;
In a combustion burner having a fuel nozzle having a primary air passage through which the primary air flows, and is disposed so as to be swingable in the vicinity of a tip portion of the pulverized coal nozzle pipe.
A combustion burner comprising an air flow rate adjusting plate provided in the secondary air nozzle pipe, which is in contact with an outer wall of the fuel nozzle, and is moved up and down as the fuel nozzle tilts. In claim 1,
The fuel nozzle is a pulverized coal nozzle having a primary air passage through which the primary air flows, and a secondary air having a secondary air passage provided around the pulverized coal nozzle and through which a part of the secondary air flows. A combustion burner characterized by having a double tube structure comprising a nozzle. In claim 1 or 2,
Provided integrally with or separately from the air flow rate adjustment plate, has a roller that contacts the outer wall of the pulverized coal nozzle, follows the vertical movement as the pulverized coal nozzle tilts, and moves the air flow rate adjustment plate up and down. Combustion burner characterized by comprising.   A boiler comprising the combustion burner according to any one of claims 1 to 3.   A pulverized coal nozzle pipe for feeding primary air for conveyance containing pulverized coal to a furnace, a secondary air nozzle pipe for feeding heated secondary air for combustion to the furnace, and the pulverized coal nozzle pipe In the combustion method of pulverized coal having a fuel nozzle having a primary air passage through which the primary air flows, the air flow rate adjusting plate provided in the secondary air nozzle pipe is The outer wall of the fuel nozzle is grounded, and as the fuel nozzle is tilted, the air flow rate adjusting plate is moved up and down, and flows between the secondary air nozzle pipe and the fuel nozzle due to the tilt change of the fuel nozzle. A method for combusting pulverized coal, characterized in that a flow area of cooling air that is a part of secondary air is made constant, and fluctuations in the flow velocity of the cooling air are prevented. In claim 5,
The fuel nozzle is a pulverized coal nozzle having a primary air passage through which the primary air flows, and a secondary air having a secondary air passage provided around the pulverized coal nozzle and through which a part of the secondary air flows. A pulverized coal combustion method characterized by having a double-pipe structure comprising a nozzle. In claim 5 or 6,
Provided integrally with or separately from the air flow rate adjustment plate, has a roller that contacts the outer wall of the pulverized coal nozzle, follows the vertical movement as the pulverized coal nozzle tilts, and moves the air flow rate adjustment plate up and down. A method for burning pulverized coal characterized by the above.

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