JP6326593B2 - Burner device, boiler using the same, and combustion method of burner device - Google Patents

Description

  The present invention relates to a burner device that burns powdered carbonaceous fuel, a boiler using the burner device, and a combustion method for the burner device.

  As boilers that generate steam for power generation and factory use, there are boilers that use powdered fuel obtained by pulverizing and pulverizing carbonaceous fuel such as coal and biomass. Such a boiler is provided with a pulverized coal burner that burns pulverized fuel to generate a flame in the furnace furnace.

  For example, the pulverized coal burner disclosed in Patent Document 1 burns pulverized coal by supplying secondary air to the outer peripheral side of the mixture while igniting a mixture of primary air and pulverized fuel to generate a flame. The structure which suppresses the quantity of NOx (nitrogen oxide) produced when it is made to be disclosed is disclosed.

  When slag adheres to the furnace wall around the pulverized coal burner as described above, so-called clinker (coal ash generated by combustion) may accumulate. When the clinker is deposited, it affects the air-fuel mixture and the flow of secondary air around the pulverized coal burner, and the stability of the flame generated by the pulverized coal burner decreases.

  Therefore, in the configuration disclosed in Patent Document 1, the outermost peripheral air flow path for flowing air along the furnace wall is provided in the outer peripheral portion of the burner. In this configuration, the slag is prevented from adhering to the furnace wall by flowing air from the outermost peripheral air flow path along the furnace wall.

JP 2001-12703 A

However, with the configuration disclosed in Patent Document 1, slag adhesion to the furnace wall around the burner can be prevented, but slag adhesion to the region between the outer periphery of the burner and the furnace wall cannot be prevented.
The present invention has been made in view of the above circumstances, and can prevent slag from adhering to the region between the outer periphery of the burner and the furnace wall, and can suppress the generation of clinker, and uses it. An object of the present invention is to provide a combustion method for a boiler and burner apparatus.

The present invention employs the following means in order to solve the above problems.
The burner device according to the present invention includes a nozzle group configured by injecting a mixture containing pulverized fuel and generating a flame toward the furnace in a vertical direction, and a vertical direction of the nozzle group. And provided at at least one of the upper end and the lower end, closing the space between the furnace wall of the furnace and the nozzle group, toward the hood panel inclined upward or downward in the vertical direction toward the inner side of the furnace wall. Or a gas injection nozzle that injects a gas along the hood panel, and the gas injection nozzle positions a part of the gas in at least one of an upper side and a lower side in the vertical direction of the gas injection nozzle. An injection unit that injects the gas toward the burner nozzle .

According to such a burner apparatus, gas can be injected from a gas injection nozzle along the hood panel provided between the outer peripheral part of the burner apparatus, and the furnace wall of the boiler in which a burner apparatus is provided. This makes it difficult for slag to adhere to the hood panel.
Moreover, it becomes possible to cool a burner nozzle with the auxiliary air injected from an injection part.

In the burner device according to the present invention, the gas injection nozzles in the burner device are arranged in at least one of the upper end and the lower end in the vertical direction of the nozzle group, and supply auxiliary air to the outer peripheral portion of the flame generated by the burner nozzle. You may make it serve as the auxiliary air supply part to perform.
By comprising in this way, auxiliary air can be supplied to the outer peripheral part of a flame from a gas injection nozzle. Therefore, the number of parts can be reduced, and the burner device can be downsized, assembled easily, and reduced in cost.

In the burner device according to the present invention, the burner nozzle in the burner device may include a cooling fin in a region where a part of the gas is injected from the injection unit.
By comprising in this way, since a cooling fin can be cooled with the auxiliary air injected from an injection part, a burner nozzle can be cooled more efficiently.

The boiler according to the present invention closes a space between the burner device, a furnace in which combustion is performed by a flame generated by the burner nozzle, a furnace wall of the furnace and the nozzle group, and an inner side of the furnace wall. A hood panel inclined upward or downward in the vertical direction is provided.
By comprising in this way, since the adhesion of the slag to the hood panel provided between the outer peripheral part of a burner apparatus and a furnace wall can be prevented, the reliability of a boiler can be improved.

A burner apparatus combustion method according to the present invention is the above-described burner apparatus combustion method, in which the air-fuel mixture is ejected from each of the burner nozzles, and the air-fuel mixture is ignited to generate a flame, and the gas Gas is sprayed from the spray nozzle toward the hood panel or along the hood panel.
By comprising in this way, adhesion of slag to a hood panel can be prevented and an air-fuel mixture can be burned efficiently.

  According to the burner apparatus according to the present invention, and the boiler using the burner apparatus and the combustion method of the burner apparatus, the slag adhesion to the region between the outer peripheral portion of the burner apparatus and the furnace wall is prevented, and the generation of clinker is suppressed. be able to.

It is a figure which shows schematic structure of the boiler provided with the burner apparatus which concerns on one Embodiment of this invention. It is a perspective view which shows the internal structure of the furnace of the said boiler. It is a sectional side view of the burner device provided at the corner of the furnace. It is a front view of the said burner apparatus. It is an expanded sectional view of the upper end part of the above-mentioned burner device. It is a sectional side view which shows the structure of the air nozzle provided in the upper-lower-end part of the said burner apparatus. It is a front view of the air nozzle.

Hereinafter, a burner device according to an embodiment of the present invention, a boiler using the burner device, and a combustion method of the burner device will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a boiler provided with the burner device of this embodiment.
As shown in FIG. 1, the boiler 10 of this embodiment includes a furnace 11, a burner device 13, a superheater 15, a reheater 16, and a economizer 17.
A flue 14 is connected to the outlet of the furnace 11. The superheater 15 is provided in the upper part of the furnace 11. The reheater 16 and the economizer 17 are provided in the flue 14. The reheater 16 and the economizer 17 are sequentially provided from the outlet side of the furnace 11 along the flow direction of the flue 14. Further, a steam drum (not shown) is provided on the upper portion of the furnace 11.

FIG. 2 is a perspective view showing the internal configuration of the furnace 11.
As shown in FIG. 2, the furnace 11 has, for example, a rectangular cross section in a horizontal plane and extends in the vertical direction. A large number of water pipes 19 are provided inside the furnace 11 so as to extend in the vertical direction. The water pipe 19 includes fins (not shown) on the outer periphery. Water is supplied to each water pipe 19 from a steam drum (not shown). A furnace wall 12 is formed inside the furnace 11 by the water pipe 19 and the fins.

  The burner device 13 is installed through the furnace wall 12 of the furnace 11. The burner device 13 in this embodiment is provided at each of the four corners of the furnace 11 having a rectangular cross-sectional shape. In addition, although the example which each provides the burner apparatus 13 in the four corners of the furnace 11 is demonstrated below, even if the burner apparatus 13 is each provided in any one surface except the ceiling surface and furnace bottom face of the furnace 11, or two opposing surfaces, respectively. Good.

FIG. 3 is a side sectional view of the burner device 13 provided at the corner of the furnace 11. FIG. 4 is a front view of the burner device 13. FIG. 5 is an enlarged cross-sectional view of the upper end portion of the burner device 13.
As shown in FIGS. 3 and 4, each burner device 13 includes a nozzle group 20 </ b> G composed of a plurality of burner nozzles 20 and an air nozzle 60 in an air box 41.

The wind box 41 includes a rectangular back plate 41a that is long in the vertical direction, and a peripheral side plate 41b that extends orthogonally from four sides of the back plate 41a. The wind box 41 is provided in through holes (not shown) formed at the four corners of the furnace 11 with the opening on the side opposite to the back plate 41 a facing the inside of the furnace 11.
In the following description, “upper” and “lower” indicate a positional relationship with respect to the vertical direction in the vertical direction.

  At the top and bottom of the wind box 41, hood panels 45 are provided for closing the space between the upper and lower ends of the peripheral side plate 41b of the wind box 41 and the furnace wall 12 of the furnace 11, respectively. The food panel 45 includes an inclined surface portion 45a and a vertical surface portion 45b continuous with the inclined surface portion 45a. The inclined surface portion 45 a is formed to be inclined so as to be gradually separated from the upper and lower centers of the wind box 41 toward the inner side of the furnace wall 12 from the upper and lower ends of the peripheral side plate 41 b of the wind box 41. The vertical surface portion 45 b is provided so as to be continuous with the furnace wall 12.

The plurality of burner nozzles 20 constituting the nozzle group 20G are installed in the wind box 41 at intervals in the vertical direction. As shown in FIG. 5, each burner nozzle 20 includes an air-fuel mixture supply pipe 21, an air-fuel mixture injection nozzle 22, and a secondary air supply nozzle 24.
The air-fuel mixture supply pipe 21 is supplied with the air-fuel mixture 105 in which the pulverized coal 100 and the primary air 101 are mixed from the pulverized coal supply means 30 (see FIG. 1).
The air-fuel mixture injection nozzle 22 is connected to the air-fuel mixture supply pipe 21. The air-fuel mixture injection nozzle 22 ejects the air-fuel mixture 105 fed from the air-fuel mixture supply pipe 21 and generates a flame when the pulverized coal 100 of the air-fuel mixture 105 is ignited by a torch (not shown).

The secondary air supply nozzle 24 is cylindrical, and is provided on the outer peripheral side of the mixture injection nozzle 22 with a gap from the mixture injection nozzle 22. A secondary air supply passage 23 is formed between the secondary air supply nozzle 24 and the air-fuel mixture injection nozzle 22.
In the secondary air supply nozzle 24, curved surfaces 24s bulging in an arc shape are formed on the upper and lower surfaces of the rear part on the air-fuel mixture supply pipe 21 side, respectively. On the inner peripheral surface of the secondary air supply nozzle 24, cooling fins 29 are formed at positions corresponding to the curved surface 24s.

A partition plate 44 extending from the outer peripheral side of the curved surface 24 s of the secondary air supply nozzle 24 toward the back plate 41 a of the wind box 41 is provided above and below each burner nozzle 20. The partition plate 44 is fixed to the wind box 41 at both ends in the width direction. The rear end portion 44a of the partition plate 44 is provided with a space between the back plate 41a.
A gap between the partition plate 44 and the air-fuel mixture supply pipe 21 of the burner nozzle 20 is a secondary air introduction path 25 that feeds the air in the wind box 41 into the secondary air supply path 23 as the secondary air 102.

Auxiliary air is supplied to the air nozzle 60 between the lower partition plate 44 of the upper burner nozzle 20 and the upper partition plate 44 of the lower burner nozzle 20 in the burner nozzles 20 adjacent to each other on the upper and lower sides of the burner device 13. An auxiliary air introduction path 26 to be described later is formed.
Each of the secondary air introduction path 25 and the auxiliary air introduction path 26 is provided with a damper member 27 for adjusting the air flow rate.

  The air nozzles 60 are respectively disposed between the burner nozzles 20 adjacent to each other in the upper and lower sides of the burner device 13, above the burner nozzle 20 positioned at the uppermost portion of the burner device 13, and below the burner nozzle 20 positioned at the lowermost portion. ing.

  As shown in FIGS. 3 and 5, the air nozzle 60 provided between the burner nozzles 20 adjacent to each other on the upper and lower sides of the burner device 13 is formed so that the flow path cross-sectional area gradually decreases in the direction of the tip 60 a. ing. The air nozzle 60 ejects the auxiliary air 108 sent from the auxiliary air introduction path 26 toward the front.

FIG. 6 is a side sectional view showing a configuration of an air nozzle (gas injection nozzle, auxiliary air supply unit) 60 </ b> S provided at the upper and lower ends of the burner device 13. FIG. 7 is a front view of the air nozzle 60S.
In the burner device 13, the air nozzles 60 </ b> S arranged above the burner nozzle 20 positioned at the top and below the burner nozzle 20 positioned at the bottom have the configurations shown in FIGS. 5 to 7.

  That is, as shown in FIGS. 5 to 7, the air nozzle 60 </ b> S is formed so that the flow path cross-sectional area gradually decreases in the direction of the tip end portion 60 b (see FIG. 5). The air nozzle 60 </ b> S is formed such that the front end portion 60 b is inclined outwardly from the vertical center of the burner device 13 toward the inside of the furnace 11. That is, the air nozzle 60S injects the auxiliary air (gas) 108 fed from the auxiliary air introduction path 26 in a direction inclined toward the upper side and the lower side, which are outside the nozzle group 20G, from the tip end portion 60b. The air nozzle 60S blows the jetted auxiliary air 108 onto the inclined surface portion 45a of the hood panel 45. The auxiliary air 108 injected from the air nozzle 60S may be blown toward the inclined surface portion 45a of the hood panel 45 or may be blown along the inclined surface portion 45a. The auxiliary air 108 injected from the air nozzle 60S preferably contacts the entire surface of the inclined surface portion 45a of the hood panel 45, and most preferably flows along the surface of the inclined surface portion 45a.

A slit (injection unit) 61 is formed on the rear side of the air nozzle 60 </ b> S on the side facing the burner nozzle 20. A part of the auxiliary air 108 sent from the auxiliary air introduction path 26 to the air nozzle 60 </ b> S is blown to the curved surface 24 s of the outer peripheral surface of the secondary air supply nozzle 24 through the slit 61.
An air guide 62 protruding from the surface of the air nozzle 60 </ b> S is provided in front of the slit 61 in the inner direction of the furnace 11. The auxiliary air 108 ejected from the slit 61 is smoothly guided to the curved surface 24 s of the secondary air supply nozzle 24 by the air guide 62.

As shown in FIG. 1, pulverized coal supply means 30 and air supply means 40 are connected to the burner device 13.
The pulverized coal supply means 30 supplies an air-fuel mixture 105 in which pulverized coal (pulverized fuel) 100 and primary air 101 are mixed to the burner nozzle 20. The pulverized coal supply means 30 includes a pulverizer 50 and a coal supply pipe 31.
The pulverizer 50 pulverizes coal supplied from a coal feeder (not shown) to a particle size suitable for combustion, thereby generating pulverized coal 100. The coal supply pipe 31 air-transports the pulverized coal 100 generated by the pulverizer 50 to the air-fuel mixture supply pipe 21 of the burner nozzle 20 using the primary air 101 as the transport air. The primary air 101 is pressurized and supplied to the coal supply pipe 31 from an air supply source (not shown).

The air supply means 40 includes a secondary air supply pipe 42 that supplies the secondary air 102 to the wind box 41.
The secondary air 102 is pressurized and sent to the secondary air supply pipe 42 from a secondary air supply source (not shown).

  A heat exchanger 43 is provided between the secondary air supply pipe 42 and the flue 14. The heat exchanger 43 performs heat exchange between the combustion exhaust gas 104 discharged from the furnace 11 to the flue 14 and the secondary air 102 flowing through the secondary air supply pipe 42. Thereby, the exhaust gas temperature of the combustion exhaust gas 104 can be lowered and the temperature of the secondary air 102 can be raised.

Next, a combustion method in the burner nozzle 20 will be described.
In the burner nozzle 20, the air-fuel mixture 105 obtained by mixing the pulverized coal 100 and the primary air 101 is supplied to the air-fuel mixture supply pipe 21 from the coal supply pipe 31 of the pulverized coal supply means 30. The air-fuel mixture 105 is ejected from the air-fuel mixture injection nozzle 22 into the furnace 11, and a pulverized coal 100 of the air-fuel mixture 105 is ignited by a torch (not shown) to generate a flame.

  The secondary air 102 is sent from the secondary air supply pipe 42 to the secondary air supply flow path 23 through the wind box 41. The secondary air 102 passes through the secondary air supply passage 23 and is ejected into the furnace 11. The secondary air is ejected to the outer peripheral side of the air-fuel mixture 105 (flame) ejected from the air-fuel mixture injection nozzle 22. Thereby, the air-fuel mixture 105 ejected from the air-fuel mixture injection nozzle 22 and the secondary air 102 supplied from the secondary air flow path on the outer peripheral side of the air-fuel mixture injection nozzle 22 are merged and agitated. Therefore, the flame holding ability of the flame is increased.

Further, auxiliary air 108 is jetted from the air nozzles 60 respectively provided above and below the air-fuel mixture jet nozzle 22. As a result, stirring of the air-fuel mixture 105 and the secondary air 102 is promoted, and flame holding properties are improved.
Further, the auxiliary air 108 is jetted from the upper and lower air nozzles 60S of the nozzle group 20G to the inclined surface portion 45a of the upper and lower hood panels 45. Thereby, the slag adhered to the hood panel 45 is discharged toward the inside of the furnace 11 along the inclined surface portion 45a of the hood panel 45.

  In the boiler 10, when a flame is generated by each burner nozzle 20, the combustion gas 103 of the pulverized coal 100 flows from the lower side to the upper side in the furnace 11. Water is supplied to the water pipe 19 provided inside the furnace wall 12 of the furnace 11 from a steam drum (not shown). The supplied water is heated by the combustion gas 103 in the furnace 11 to become saturated steam while flowing through the water pipe 19 from the lower direction to the upper direction.

  This saturated steam is introduced into the superheater 15 via a steam drum (not shown). In the superheater 15, the saturated steam is heated by the combustion gas 103 in the furnace 11 and becomes superheated steam. The superheated steam generated by the superheater 15 is supplied to a desired turbine or the like for power generation or the like.

The combustion gas 103 that has passed through the superheater 15 is discharged from the flue 14 as combustion exhaust gas 104.
The reheater 16 provided in the flue 14 reheats the steam taken out during the expansion process in the turbine by the flue gas 104 and returns it to the turbine.
In the economizer 17, water supplied to a steam drum (not shown) is preheated by exchanging heat with the combustion exhaust gas 104. The combustion exhaust gas 104 that has passed through the economizer 17 is supplied with heat energy to the secondary air 102 that passes through the secondary air supply pipe 42 in the heat exchanger 43 and subjected to treatment such as desulfurization, denitration, and dust removal. It is discharged into the atmosphere from the chimney.

  Therefore, according to the combustion method of the burner device 13, the boiler 10, and the burner device 13 of the above-described embodiment, the auxiliary air 108 is injected from the air nozzle 60S to the inclined surface portion 45a of the hood panel 45. Accordingly, it is possible to prevent slag from adhering to the hood panel 45 located in the region between the outer peripheral portion of the burner device 13 and the furnace wall 12 of the boiler 10 in which the burner device 13 is provided. As a result, the generation of clinker can be suppressed. As a result, the labor of maintenance of the furnace 11 can be reduced and the life of the furnace 11 can be extended.

  Further, the air nozzle 60S supplies the auxiliary air 108 in order to enhance the flame holding property of the flame generated by the burner nozzle 20 and the function of injecting the auxiliary air 108 to prevent the slag from adhering to the hood panel 45. With functionality. Therefore, the number of parts can be reduced as compared with a configuration in which nozzles are separately provided to realize each function. As a result, the burner device 13 can be reduced in size, facilitated assembly, and reduced in cost.

  Furthermore, since the air nozzle 60S injects a part of the auxiliary air 108 toward the burner nozzle 20, the burner nozzle 20 can be cooled.

  In addition, since the burner nozzle 20 includes the cooling fin 29 in a region where a part of the auxiliary air 108 is injected from the air nozzle 60, the cooling fin 29 can be cooled. As a result, the burner nozzle 20 can be cooled more efficiently.

(Other variations)
The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention. That is, the specific shapes, configurations, and the like given in the embodiments are merely examples, and can be changed as appropriate.
For example, in the above-described embodiment, the case where a part of the auxiliary air 108 ejected from the slit 61 is ejected toward the curved surface 24s of the burner nozzle 20 by the air guide 62 from the air nozzle 60S has been described. However, it is not limited to this configuration. For example, a slit may be formed in the air nozzle 60 provided between the burner nozzles 20 adjacent in the vertical direction, and a part of the auxiliary air 108 may be ejected from the slit toward the burner nozzle 20. Moreover, the target site | part which injects a part of auxiliary air 108 is not restricted to the curved surface 24s. Moreover, although the case where the air nozzle 60S also serves as the auxiliary air supply unit has been described, the air nozzle 60S and the auxiliary air supply unit may be provided separately.

  Furthermore, the injection direction of the auxiliary air 108 injected from the air nozzle 60S is not limited to a parallel direction as long as it is along the inclined surface portion 45a of the hood panel 45. The injection direction of the auxiliary air 108 may be inclined upward or downward. For example, the injection direction and the surface of the hood panel 45 may intersect.

  Moreover, in embodiment mentioned above, the gas injection nozzle 60S demonstrated the case where the gas 108 was injected along the hood panel 45 provided in both the upper end and lower end of the nozzle group 20G. However, the present invention is not limited to this configuration. For example, the gas 108 may be injected along the hood panel 45 provided on at least one of the upper end and the lower end of the nozzle group 20G.

Furthermore, the case where the air nozzle 60S mentioned above injects a part of auxiliary air 108 toward the burner nozzle 20 located above the air nozzle 60S and the burner nozzle 20 located below was demonstrated. However, the present invention is not limited to this configuration, and a part of the auxiliary air 108 may be injected toward the burner nozzle 20 positioned at least one of the upper side and the lower side, for example.
Further, for example, the configuration of each part of the burner nozzle 20 and the boiler 10 may be any other configuration.
Furthermore, in the above-described embodiment, pulverized coal is used as the fuel, but the present invention is not limited to this. For example, pulverized carbonaceous fuel can be used as the fuel.

10 boiler 11 furnace 12 furnace wall 13 burner device 14 flue 15 superheater 16 reheater 17 economizer 19 water pipe 20 burner nozzle 20G nozzle group 21 mixture supply pipe 22 mixture injection nozzle 23 secondary air supply flow path 24 Secondary air supply nozzle 24s Curved surface 25 Secondary air introduction path 26 Auxiliary air introduction path 27 Damper member 29 Cooling fin 30 Pulverized coal supply means 31 Coal supply pipe 40 Air supply means 41 Wind box 41a Back plate 41b Surrounding side plate 42 Secondary air Supply pipe 43 Heat exchanger 44 Partition plate 44a Rear end 45 Hood panel 45a Inclined surface 45b Vertical surface 50 Crusher 60 Air nozzle 60S Air nozzle (gas injection nozzle, auxiliary air supply unit)
60a tip 60b tip 61 slit (jetting part)
100 pulverized coal (powder fuel)
101 Primary air 102 Secondary air 103 Combustion gas 104 Combustion exhaust gas 105 Mixture 108 Auxiliary air (gas)

Claims (5)

A group of nozzles configured by arranging a plurality of burner nozzles vertically in the vertical direction by injecting an air-fuel mixture containing pulverized fuel and generating flames in the furnace;
Provided in at least one of the upper end and the lower end in the vertical direction of the nozzle group, block between the furnace wall of the furnace and the nozzle group, and inclined upward or downward in the vertical direction toward the inner side of the furnace wall A gas injection nozzle for injecting gas toward the hood panel or along the hood panel;
Equipped with a,
The said gas injection nozzle is a burner apparatus provided with the injection part which injects a part of said gas toward the said burner nozzle located in at least one of the upper direction and the downward direction in the perpendicular direction of the said gas injection nozzle .   The burner device according to claim 1, wherein the burner nozzle includes a cooling fin in a region where a part of the gas is injected from the injection unit.   The gas injection nozzle is disposed at least one of an upper end and a lower end in a vertical direction of the nozzle group, and also serves as an auxiliary air supply unit that supplies auxiliary air to an outer peripheral portion of the flame generated by the burner nozzle. The burner device according to 2. The burner device according to any one of claims 1 to 3,
The furnace in which the combustion is performed by the flame generated by the burner nozzle, and the furnace wall of the furnace and the nozzle group are closed, and inclined upward or downward in the vertical direction toward the inner side of the furnace wall. A boiler with a hood panel. It is a combustion method of the burner device according to any one of claims 1 to 3,
The air-fuel mixture is ejected from each of the burner nozzles, and a flame is generated when the air-fuel mixture is ignited, and gas is injected from the gas injection nozzle toward the hood panel or along the hood panel. Burning method of burner device.

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