JP2001082705A - Pulverized fuel combustion burner, boiler, and pulverized fuel combustion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulverized coal fuel combustion burner to perform combustion of crushed coal through direct feed and to provide a boiler provided with the burner. SOLUTION: This burner comprises a pulverized coal conveyance line 9; an ultra thick A/C mixture compartment 14 to jet pulverized coal mixture fed through the line; an ultra thin A/C mixture compartment 15; and an auxiliary air compartment 16, and the devices respectively individually jet a plurality of kinds of fed pulverized coal mixtures different in concentration. In a so formed pulverized fuel combustion burner, pulverized coal mixture fed to the vicinity of a connection part between an ultra thick A/C mixture nozzle pipe 114b of the ultra thick A/C mixture compartment 14 to jet high concentration pulverized coal mixture and the pulverized coal conveyance line 9 is blown in a tangential direction with the cross section of the ultra thick A/C mixture nozzle pipe 114b, and a speed regulation damper to regulate a blow speed is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulverized fuel combustion burner, a boiler, and a pulverized fuel combustion method used for generating steam in power generation or factories.

[0002]

2. Description of the Related Art Conventionally, when burning a solid fuel such as coal having a low volatile content or a high fuel ratio (fixed carbon content / volatile content), it is necessary to consider that the volatile content is small and it is very difficult to burn. For the purpose of facilitating combustion, the solid fuel is once pulverized and stored, and is conveyed by air to combust with the weight ratio of the amount of pulverized coal to the amount of air being suppressed to a low level. This example will be described with reference to FIGS. 13 and 14. In FIG. 13, reference numeral 1 denotes a pulverized coal transporting blower, which is connected to the coal pulverizer 2 via a pulverized coal transporting air line 8. ing. The coal pulverizer 2 is connected to a pulverized coal collector 3 via a pulverized coal transport line 9.

[0003] A pulverized coal storage tank 4 is disposed below the pulverized coal collector 3, and a discharge side of the pulverized coal storage tank 4 is a constant-rate feeder 4a.
And is connected to a primary air / pulverized coal (hereinafter, referred to as A / C) mixture line 10 through a line. The A / C mixture line 10 feeds coal exhaust to a coal exhaust blower 7 by a primary air blower 6 provided on the upstream side. Coal blower 7
Is branched into a plurality of portions, and a well-known dense and light pulverized coal separator 5 is connected to each branch portion. Each of the above-mentioned rich and light pulverized coal separators 5 has a rich A / C mixture line 11 and a light A / C
An air-fuel mixture line 12 is connected, and as shown in FIG.
The / C mixture line 11 is connected to the rich A / C mixture compartment 14, and the light A / C mixture line 12 is connected to the light A / C mixture compartment 15.

Here, the rich A / C mixture compartment 14 and the light A / C mixture compartment 15 are arranged adjacent to each other, and the light A / C mixture compartment 15 is further provided with the pulverized coal collector 3. An auxiliary air compartment 16 connected to the exhaust line 17 is arranged adjacent to the exhaust line 17, and a plurality of sets of the rich A / C air-fuel mixture compartment 14, the light A / C air-fuel mixture compartment 15, and the auxiliary air compartment 16 are arranged. It is provided toward the furnace inside 23 (not shown). The rich A / C mixture compartment 14, the light A / C mixture compartment 15, and the auxiliary air compartment 16 are provided in the burner-like box 1
3 are provided.

[0005] The rich A / C mixture compartment 14
Is a concentrated A / C with a concentrated A / C mixture nozzle 14a at the tip.
The air for the rich A / C mixture 2
2A, and a light A / C mixture compartment 15 is provided around a light A / C jet nozzle pipe 15b having a light A / C mixture nozzle 15a at the tip. The auxiliary air compartment 16 has a flow path for the air 22b, and the auxiliary air compartment 16 has a flow path for the auxiliary air 22c around the exhaust jet nozzle tube 16b having the auxiliary air nozzle 16a at the tip.

[0006] Here, the air 22a for the rich A / C mixture is used.
As shown in FIG. 13, the air for lean A / C mixture 22 b and the auxiliary air 22 c are supplied from the secondary air line 18 to the secondary air 22.
Sent as Then, each concentrated A / C mixture nozzle 1
The rich flame 19a and the light flame 20a are jetted into the furnace 23 from the 4a and the light A / C mixture nozzle 15a.
The exhaust gas 21 of the pulverized coal collector 3 ejected from the auxiliary air nozzle 16a is provided for combustion in the furnace 23 together with the auxiliary air 22c.

[0007] Therefore, the coal 8 brought in from the coal storage
b is supplied to the coal pulverizer 2 together with the pulverized coal transport air 8a sent from the pulverized coal transport air line 8 by the pulverized coal transport blower 1. The coal 8b pulverized by the coal pulverizer 2 is mixed with pulverized coal transport air 8a, and sent to the pulverized coal collector 3 from the pulverized coal transport line 9 as a pulverized coal mixture 9a. Here, the “pulverized coal transport air 8a / pulverized coal transport air 8a /
The “coal 8 b” ratio varies depending on the performance of the coal crusher 2, but is generally about 2 or more by weight.

[0008] The pulverized coal mixture 9a sent to the pulverized coal collector 3 is separated into pulverized coal and exhaust gas 21, and the collected pulverized coal is temporarily stored in the pulverized coal storage tank 4. In addition, exhaust 2
In 1, pulverized coal remains. The pulverized coal stored in the pulverized coal storage tank 4 is cut out by the pulverized coal quantitative feeder 4a and supplied to the primary air line 6a. Primary air 6b sent by the primary air blower 6 flows through the primary air line 6a, and mixes with the pulverized coal supplied from the pulverized coal storage tank 4 to form an A / C mixture 10a. Charcoal blower 7
Sent to

The A / C mixture 10a is supplied from the A / C mixture line 10 by the coal exhaust blower 7 to the light and fine pulverized coal separator 5.
Into the dense and fine pulverized coal separator 5
/ A / C mixture 19 and a light A / C mixture 20
A / C mixture line 11 and a light A / C mixture line 12 are fed to a rich A / C mixture compartment 14 and a light A / C mixture compartment 15.

On the other hand, the combustion air is the A / C mixture 1
In addition to the primary air 6b supplied as Oa, the secondary air 22 occupying most of the combustion air is passed through the secondary air line 18 to each compartment 14, 1 in the burner wind box 13.
To 5 and 16 respectively, air 22a and 22b for A / C mixture
And as auxiliary air 22c.

The density A / C mixtures 19 and 20 sent from the density A / C mixture lines 11 and 12 to the density A / C compartments 14 and 15 respectively are density A / C jet nozzle tubes 14b and 15b. Through the nozzles at the center of the A / C mixture nozzles 14a and 15a into the furnace 23, and ignited and burned by an ignition source (not shown) to form the two-sided flames 19a and 20a. The rich flame 19a formed by the ignition and combustion of the rich A / C mixture 19 shows a stable ignition state close to the tip of the rich A / C mixture nozzle 14a. On the other hand, the light flame 20a formed by the ignited combustion of the lean A / C mixture 20 ignites far away from the tip of the lean A / C mixture nozzle 15a, and the stability of the ignited portion is determined by the rich flame 19a and the inside of the furnace. 23, in particular, is maintained by the former radiant heat.

[0012] Also, 2 is sent separately to the burner wind box 13
The secondary air 22 is supplied to each of the compartments 14, 15, 16
Each of the nozzles 14a, 15a, 16a attached to the furnace is jetted into the furnace 23 and formed into the dark and light flames 19a, 20
a. On the other hand, the exhaust gas 21 separated by the pulverized coal collector 3 is supplied from the exhaust line 17 to the burner wind box 13.
Then, the pulverized coal which is ejected from the auxiliary air nozzle 16a into the furnace 23 through the exhaust nozzle pipe 16b of the auxiliary air compartment 16 and remains in the exhaust gas 21 is burned. The pulverization of the coal 8b is independent of the amount of the A / C mixture 10a used (burner load or boiler load).
Depending on the amount of pulverized coal stored in the pulverized coal storage tank 4, the ventilation of the exhaust 21 of the pulverized coal collector 3 is sometimes stopped. As this kind of technology, for example, Japanese Unexamined Patent Publication No.
There is one disclosed in 2006616.

[0013]

In order to maintain stable combustion in pulverized coal combustion, it is an essential condition to ensure ignition stability of the pulverized coal flame. Generally, in the pulverized coal combustion, the ignitability of the pulverized coal flame decreases as the fuel ratio (fixed carbon content / volatile content) of the pulverized coal decreases and the A / C of the pulverized coal mixture when injected into the furnace decreases (there is a limit). ) Is known to be good. However, the A / C of the pulverized coal mixture 9a formed and sent out by the coal pulverizer 2 is substantially 2 or more.
A / C on the / C mixture 19 side is only about 1.5, and a direct system in which solid fuel having a low volatile content and a high fuel ratio is supplied directly from the coal crusher 2 to the boiler is employed. Was difficult.

Therefore, when low-volatile / high-fuel-ratio coal having a volatile content of about 10% or less or a fuel ratio exceeding 5 is used as a boiler fuel, for example, the pulverized coal 8b is collected as pulverized coal. A line for separating and collecting the pulverized coal into a pulverized coal storage tank 4 by a vessel 3, and adjusting the amount of pulverized coal and the amount of primary air 6b so that the stored pulverized coal becomes an A / C mixture 10a having excellent ignitability. There is no other choice but to use a semi-bin system having a line for feeding the wind box 13 to the wind box 13, and there is a problem that the equipment becomes large and the equipment cost increases. Accordingly, the present invention provides a pulverized fuel combustion burner that can burn solid fuel with a low volatile content and a high fuel ratio even if the pulverized fuel storage tank is abolished, a boiler that can perform efficient operation, and a concentration adjustment accuracy. An object of the present invention is to provide a pulverized fuel combustion method that can be enhanced.

[0015]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention described in claim 1 comprises mixing a finely pulverized solid fuel (for example, coal in the embodiment) with air or other gas, A pulverized fuel supply pipe (for example, the pulverized coal transport line 9 in the embodiment) that supplies the pulverized fuel mixture, and a plurality of burner nozzles (for example, pulverized fuel mixture supplied from each pulverized fuel supply pipe) The embodiment includes a super-rich A / C mixture compartment 14, a lean A / C mixture compartment 15, and an auxiliary air compartment 16), and the burner nozzles respectively supply a plurality of types of pulverized fuel mixtures having different concentrations to be supplied. In a pulverized fuel combustion burner that is configured to be able to eject individually,
A burner nozzle (e.g., the ultra-rich A / C mixture compartment 14 in the embodiment) that ejects a high-concentration pulverized fuel mixture and a pulverized fuel supply pipe are provided near the connection between the pulverized fuel supply pipe and the burner nozzle. Tubes (for example,
Ultra-rich A / C mixture nozzle tube 114b in the embodiment)
Is provided with a speed adjusting damper (for example, the speed adjusting damper 124 in the embodiment) capable of blowing in a tangential direction with respect to the transverse section and adjusting the blowing speed.

With this configuration, it is possible to adjust the concentration of the pulverized fuel mixture by adjusting the blowing speed by the speed adjusting damper. To increase the concentration of the pulverized fuel mixture, for example, adjust the direction of the inflow port by using a speed adjustment damper to increase the flow velocity, and to decrease the concentration of the pulverized fuel mixture, for example, to open the inflow port by using a speed adjustment damper. Do this by lowering the flow rate by adjusting to.

The invention described in claim 2 is characterized in that the solid fuel has a fuel ratio (fixed carbon content / volatile content) of 2 or more or a volatile content of 10% or less. With this configuration, it is possible to use a fine powder fuel mixture obtained by finely pulverizing the solid fuel as it is.

According to a third aspect of the present invention, the nozzle pipe of the burner nozzle for jetting the high-concentration pulverized fuel mixture is opened in the nozzle pipe, and a part of the pulverized fuel mixture is sucked to mix the pulverized fuel mixture in the nozzle pipe. An air-fuel mixture discharge nozzle pipe (for example, an air-fuel mixture exhaust nozzle pipe 114c in the embodiment) that adjusts the gas concentration and supplies the sucked fine fuel mixture to another burner nozzle (for example, the auxiliary air compartment 16 in the embodiment). The mixture discharge nozzle pipe is provided with a position adjusting operation device (for example, the mixture discharge pipe operation device 1 in the embodiment) for adjusting the insertion position of the mixture gas discharge nozzle tube.
26) is mounted.

With such a configuration, the position of the air-fuel mixture discharge nozzle pipe is adjusted by the position adjusting operation device,
For example, when the air-fuel mixture discharge nozzle pipe is inserted in the direction of injection of the nozzle pipe, the concentration of the exhaust air-fuel mixture increases, and when it is pulled out in the opposite direction, the concentration of the exhaust air-fuel mixture decreases. The concentration of the fine fuel mixture can be adjusted.

According to a fourth aspect of the present invention, there is provided a supply path (for example, between the above-described mixture discharge nozzle pipe and another nozzle pipe for burning the pulverized fuel-fuel mixture discharged by the mixture discharge nozzle pipe). The ultra-lean A / C mixture line 117 in the embodiment is provided with a flow control device (for example, the flow control damper 114d in the embodiment). With this configuration, it is possible to adjust the concentration of the high-concentration pulverized fuel mixture ejected from the nozzle tube by using the position adjusting operation device together.

According to a fifth aspect of the present invention, the nozzle pipe of the burner nozzle for ejecting the high-concentration fine-powder fuel mixture is provided with a high-concentration fine-powder mixture at the outer periphery of the fine-powder fuel mixture ejected from the nozzle pipe. It is characterized in that a density separator (for example, a density separator 127 in the embodiment) that forms a fuel mixture is provided. With this configuration, it is possible to increase the concentration of the pulverized fuel mixture on the outer peripheral side of the flame.

According to a sixth aspect of the present invention, in the nozzle pipe of the burner nozzle for jetting the high-concentration pulverized fuel-air mixture, the high-concentration air-fuel mixture and the low-concentration air-fuel mixture are divided into two parts. It is characterized in that a light and shade divided body (for example, a light and shade divided body 128 in the embodiment) capable of separately ejecting the air-fuel mixture is provided. With this configuration, it is possible to increase the concentration of the pulverized fuel / fuel mixture at one side of the flame.

According to a seventh aspect of the present invention, the primary air / fuel weight ratio of the high concentration pulverized fuel mixture is 0.75 to 1.2.
5 is set. With this configuration, the volatile component is low (for example, 10% in the embodiment).
% Or less), it is possible to shorten the ignition distance.

According to the invention described in claim 8, the burner nozzle according to any one of claims 1 to 7, wherein the burner nozzle is provided in a plurality of stages vertically on each wall surface or each corner portion of the furnace. Wherein a pulverized fuel-fuel mixture supplied to each burner nozzle is blown in a tangential direction to a virtual circle set at a substantially central portion of a furnace section to perform swirling combustion. With such a configuration, efficient heating can be achieved by stable combustion of the pulverized fuel combustion burner.

According to a ninth aspect of the present invention, a finely pulverized solid fuel is mixed with air or other gas, and this finely divided fuel mixture is separated into finely divided fuel mixtures having different concentrations, each of which is ejected by a burner nozzle. At the time, the low-concentration portion of the high-concentration pulverized fuel mixture supplied to the burner nozzle for the high-concentration pulverized fuel mixture is supplied to the burner nozzle for the low-concentration pulverized fuel mixture to supply the high-concentration pulverized fuel mixture. The combustion is performed in a state where the concentration of the fine fuel mixture in the burner nozzle for the fuel mixture is adjusted. With this configuration, it is possible to directly control the concentration of the pulverized fuel mixture immediately before combustion.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings, in which the same reference numerals are given to the same parts as those of the above-mentioned conventional structure. FIGS. 1 to 5 show a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a pulverized coal transporting blower. The pulverized coal transporting blower 1 is connected to a coal pulverizer 2 via a pulverized coal transporting air line 8. A pulverized coal transfer line 9 is connected to the coal pulverizer 2, and the pulverized coal transfer line 9 is branched, and a well-known thick and light pulverized coal separator 5 is connected to each branch.

Therefore, unlike the prior art, no pulverized coal storage tank is provided. Each of the above fine and light pulverized coal separators 5 includes:
Rich A / C mixture line 11 and light A / C mixture line 12
The rich A / C mixture line 11 is connected to the rich A / C mixture compartment 14 and the light A / C mixture line 12 is connected to the light A / C mixture compartment 15 as shown in FIG. It is connected.

Here, the rich A / C mixture compartment 14 and the light A / C mixture compartment 15 are arranged adjacent to each other, and the light A / C mixture compartment 15 is further adjacent to an auxiliary air compartment 16. These rich A / C mixture compartments 1
A plurality of sets 4, a light A / C mixture compartment 15, and an auxiliary air compartment 16 are arranged in the vertical direction and provided toward the furnace interior 23. The rich A / C mixture compartment 14, the light A / C mixture compartment 15, and the auxiliary air compartment 16 are provided in a burner-like box 13.

The rich A / C mixture compartment 14
Is provided with a flow path of a rich A / C mixture air 22a around a super rich A / C jet nozzle tube 114b having a very rich A / C mixture nozzle 114a at the tip. On the inflow side of the C ejection nozzle pipe 114b, an air-fuel mixture exhaust nozzle pipe 114 is provided.
The c-rich A / C ejection nozzle tube 114b is inserted so as to be able to advance and retreat along the longitudinal direction. The concentrated A / C mixture line 11 is connected to the peripheral wall of the portion of the super-rich A / C jet nozzle tube 114b inserted into the mixture exhaust nozzle tube 114c, and a speed adjusting damper 124 described later is provided at this connection portion. Have been.

The mixture gas discharge nozzle pipe 114c is provided with a mixture discharge pipe operating device 126 for changing the amount of insertion into the ultra-concentrated A / C ejection nozzle pipe 114b and adjusting the set position. As shown in FIG. 3, the air-fuel mixture discharge pipe operating device 126 includes a clamp member 126a for holding an end of the air-fuel mixture exhaust nozzle pipe 114c.
Is configured to be movable along a guide rail 126b provided in the longitudinal direction. Position adjustment is performed by manually or withdrawing the arm 126c provided on the clamp member 126a by a driving device. The mixture exhaust nozzle pipe 114c has changed from a round cross-sectional shape to a square cross-sectional shape on the tip side, but at the end of the round cross-sectional shape, in order to eliminate the unbalanced flow or concentration distribution of the passing fluid. Is provided.

As shown in FIG. 5, the speed adjusting damper 124 has a substantially fan-shaped damper body 124a which rotates about the longitudinal direction of the super-concentrated A / C jet nozzle tube 114b. (Shown in FIG. 3)
By rotating in the direction of the arrow, the flow area can be adjusted by adjusting the flow area of the rich A / C mixture line 11, and the concentration can be increased in the tangential direction of the cross section of the super-rich A / C jet nozzle tube 114b. The A / C mixture 119 can be supplied while swirling. In rotating the damper body 124a, a driving device (not shown) can be used manually. The light A / C mixture compartment 1
5 is a light A / C mixture nozzle 1 at the tip as in the prior art.
A around the light A / C ejection nozzle pipe 15b provided with the light A
/ C air flow path 22b.

The auxiliary air compartment 16 is provided with a flow path for auxiliary air 22c around an ultra-light A / C jet nozzle tube 116b having an auxiliary air nozzle 16a at the tip. The ultra-light A / C jet nozzle pipe 116b is connected to the air-fuel mixture exhaust nozzle pipe 114c of the rich A / C air-fuel mixture compartment 14 via an ultra-light A / C air-fuel mixture line 117. The ultra-lean A / C mixture line 117 is provided with a flow control damper 114d, and the flow rate of the ultra-lean A / C mixture 119b flowing from the mixture exhaust nozzle pipe 114c toward the ultra-lean A / C jet nozzle pipe 116b. Can be adjusted. Here, the air for rich A / C mixture 22a, the air for lean A / C mixture 22b, and the auxiliary air 2a
2c is supplied as secondary air 22 from the secondary air line 18 as shown in FIG.

The ultra-lean A / C mixture 119 b is supplied to the ultra-lean A / C jet nozzle pipe 11 of the auxiliary air compartment 16.
The air may be supplied so as to be drawn in by the auxiliary air 22c ejected from the nozzle 6b, or may be supplied using a blowing device (not shown). In addition, the air-fuel mixture discharge pipe operating device 1
26, the speed adjustment damper 124, and the flow control damper 114
d may be operated independently, or two or all of them may be controlled in cooperation. Thus, the mixture discharge pipe operating device 126 and the speed adjusting damper 12
4. The optimum combustion state can be realized by operating the flow control damper 114d.

That is, as shown in FIG. 12, when the fuel ratio = fixed carbon / volatile content is changed, the ignition distance (mm) and A
From the relationship with / C, the value of A / C is 0.7
Since the ignition distance (distance from ejection to combustion) becomes short within the range of 5 to 1.25, and a flame excellent in ignition stability can be formed, the A / C is 0.75 to 1.25.
The mixture discharge pipe operating device 126, the speed adjusting damper 124, and the flow rate control damper 114d are operated so as to fall within the range. The pulverized fuel combustion burner thus configured is vertically installed on each wall or each corner of the furnace 23 of the boiler (not shown), and the supplied pulverized fuel mixture is substantially at the center of the furnace section. Swirl combustion is performed by blowing the imaginary circle in the tangential direction.

According to the above-described embodiment, the concentrated A / C mixture 119 formed by the concentrated pulverized coal separator 5 is supplied from the concentrated A / C mixture line 11 through the speed adjusting damper 124 to the concentrated A / C mixture.
The super-rich A / C jet nozzle tube 114 b of the / C mixture compartment 14 is fed into the air-fuel mixture compartment 14. The injection of the rich A / C mixture 119 into the super-rich A / C ejection nozzle pipe 114b is performed by the speed adjusting damper 124 in a tangential direction to a transverse section (circle) of the super-rich A / C ejection nozzle pipe 114b. And the resulting centrifugal force causes a rich A / C mixture 1
Numeral 19 is sent while turning in an annular passage formed by the super-concentrated A / C jet nozzle pipe 114b and the mixture gas exhaust nozzle pipe 114c mounted therein.

Due to this turning force, the super-rich A
A high-concentration pulverized coal mixture along the inner wall of the / C ejection nozzle pipe 114b and a low-concentration pulverized coal mixture along the outer wall of the mixture exhaust nozzle pipe 114c are formed. Here, A / C
The density separation of the air-fuel mixture 119 is as follows:
The opening is adjusted by adjusting the opening of the speed adjusting damper 124 provided at the inlet of the 14b, and the difference in density can be increased by decreasing the opening of the damper 124 and increasing the blowing speed of the rich A / C mixture 119. . When the blowing speed is increased, the pulverized coal mixture concentration increases, and when the blowing speed is reduced, the pulverized coal mixture concentration decreases.

Thus, the air-fuel mixture exhaust nozzle tube 114
A super-rich A / C jet nozzle tube 114b near the inlet c
Inside, there is an ultra-rich A / C mixture 119a along the inner wall surface of the jet nozzle tube 114b, and an ultra-lean A / C mixture 1
19b are each formed. Super-rich A / C jet nozzle tube 11
Ultra-light A / C mixture 119 formed at the center of the cross section 4b
b is discharged from the air-fuel mixture exhaust nozzle pipe 114c to the outside of the ultra-concentrated A / C jet nozzle pipe 114b.
The super-rich A / C mixture 119a formed on the peripheral wall portion b is sent to the super-rich A / C mixture nozzle 114a through the super-rich A / C jet nozzle tube 114b while turning. Then, the super-rich A / C mixture 11 sent while rotating
9a is rectified by the swirl preventing body 125, is blown into the furnace 23 from the super rich A / C mixture nozzle 114a, and ignites to form a stable rich flame 19a.

The A / C of the super-rich A / C mixture 119a is performed by adjusting the pulverized coal concentration and the flow rate of the ultra-lean A / C mixture 119b. In other words, the concentration of the ultra-lean A / C mixture 119b is controlled by operating the mixture exhaust pipe operating device 126 to bring the mixture air exhaust nozzle pipe 114c in and out. In particular,
When the air-fuel mixture exhaust nozzle pipe 114c is pushed into the inside of the super-concentrated A / C jet nozzle pipe 114b, the concentration becomes high (the concentration of the super-concentrated A / C mixture 119a becomes low), and when it is pulled out, the concentration becomes low (super-concentration). The concentration of the rich A / C mixture 119a becomes higher).

Accordingly, since the concentration of the pulverized fuel mixture immediately before combustion can be directly manipulated, the adjustment accuracy can be improved. Also, ultra-light A / C
By controlling the flow rate of the air-fuel mixture 119b by adjusting the flow control damper 114d, the super-rich A / C air-fuel mixture 1b is controlled.
The density of 19a can be adjusted. Ultra-lean A / C mixture 119b discharged from mixture exhaust nozzle pipe 114c
Flows through the ultra-lean A / C mixture line 117 after the flow rate is adjusted by the flow rate control damper 114d.
The auxiliary air nozzle 16 is sent to the ejection nozzle pipe 116b,
a into the furnace 23 and burn.

Therefore, according to the above embodiment, the pulverized coal collector 3 and the pulverized coal storage tank 4 can be eliminated as in the prior art, and the pulverized coal mixture 9a crushed by the coal crusher 2 can be used as it is. Therefore, the size of the apparatus can be reduced. Needless to say, the speed adjusting damper 124, the mixture discharge pipe operating device 12
6. The A / C is 0.75 by the flow control damper 114d.
Since combustion can be performed in the range of １．２1.25, combustion with high ignition stability and high efficiency can be realized. Further, according to the boiler provided with the above-described pulverized fuel combustion burner, efficient heating can be performed by stable combustion of the pulverized fuel combustion burner, and thus efficient and stable operation can be realized.

Next, a second embodiment of the present invention will be described with reference to FIGS. Note that the same parts as those of the above-described embodiment are denoted by the same reference numerals and described. In the first embodiment described above, the super-rich A / C mixture 119a formed in the super-rich A / C ejection nozzle pipe 114b is rectified, the concentration distribution of the pulverized coal is made uniform, and the super-rich A / C mixture is made. Although the second embodiment blows the super-rich A / C mixture 119a from the nozzle 114a into the furnace 23, the outer peripheral surface of the flow of the super-rich A / C mixture 119a ejected from the nozzle 114a is particularly high-concentration, and the rich flame is increased. 1
9a is intended to improve the ignition stability.

Specifically, as shown in FIG. 7 and FIG.
A density separator 127 is provided in the vicinity of the outlet portion in the super-concentrated A / C jet nozzle tube 114b in the embodiment, and the density-separated body 127 is fixed to the inner wall of the super-concentrated A / C jet nozzle tube 114b by a support plate 127a. A partition wall 127b is provided inside the density separation body 127. Another light / dark separator 127 is also attached to the tip of the super-rich A / C mixture nozzle 114a.

Accordingly, the super-rich A / C jet nozzle tube 11
The rich A / C mixture 119 sent into the inside 4b is centrifuged and the ultra-rich A / C mixture 119a and the ultra-lean A / C mixture 11 are separated.
9b, the ultra-lean A / C mixture 119b is fed into the auxiliary air compartment 16 from the mixture discharger 114c. On the other hand, the super-concentrated A / C mixture 119a, while having a swirling force, reaches the light-and-dark separator 127 provided near the outlet in the super-concentrated A / C ejection nozzle tube 114b, and the outer periphery of the ejection nozzle tube 114b. High concentration mixture 11 formed in the part
Reference numeral 9c denotes the outside of the light / dark separator 127, and the low-concentration air-fuel mixture 119d formed at the center thereof is discharged through the inside of the light / dark separator 127.

The light / dark separator 127 is fixed to the inner wall of the ultra-high concentration A / C jet nozzle tube 114b by a support plate 127a.
In 9c, the turning force is extinguished by the support plate 127a, and the turning force of the low-concentration air-fuel mixture 119d passing through the inside of the density separator 127 is extinguished by the partition plate 127b provided in the separator 127. As a result, the super-rich A / C mixture 119a ejected from the super-rich A / C mixture nozzle 114a
In this case, the outer surface has a high concentration, and the formed deep flame 19a has a higher ignition stability.

Therefore, in the second embodiment, in addition to the basic effects of the first embodiment, the super-rich A / C mixture 11a ejected from the super-rich A / C mixture nozzle 114a has a highly concentrated outer surface. Thus, there is an effect that the formed rich flame 19a has more ignition stability.

Next, a third embodiment of the present invention will be described with reference to FIGS. The same parts as those in the first embodiment will be described with the same reference numerals. This embodiment is
Super-concentration A formed in super-concentration A / C ejection nozzle tube 114b
/ C air-fuel mixture 119a to the super-rich A / C jet nozzle tube 11
4b, a high-concentration portion and a low-concentration portion are separated from each other in the vicinity of the outlet portion and are ejected from the super-rich A / C mixture nozzle 114a.
9a is intended to improve the ignition stability.

More specifically, a density divider 128 is provided downstream of the turning prevention member 125 in the first embodiment. As shown in FIG. 10, the light and shade divider 128 has a pair of right-angled triangular pieces 128a and 128b at the bottom side (the side where the rotation preventing body 125 is not provided) and the upper side (the side where the rotation preventing body 125 is provided). ), And an even number of these sets are arranged in the horizontal direction in FIG. The piece 128a has a larger end face height than the piece 128b.
Both a and 128b are mounted with their end faces facing each other in the longitudinal direction of the super-concentrated A / C ejection nozzle tube 114b. That is, as can be understood from FIG. 9 by changing the end surface height in this way, tapered guide paths are formed alternately from the bottom side toward the top side and from the top side toward the bottom side. It is done.

Therefore, the super-rich A / C jet nozzle tube 11
When the super-rich A / C mixture 119a formed in 4b collides with the swirl preventing body 125, the swirling is extinguished and at the same time, the jet nozzle pipe 114b near the entrance of the shading splitter 128.
A low-concentration mixture 119c is formed on the bottom side and a low-concentration mixture 119d is formed on the top side. The light and shade divided body 128 is vertically divided into an even number and can be alternately fed upward at the bottom side and downward at the upper side.
9c is ejected from the upper mixture jetting portion of the super-rich A / C mixture nozzle 114a, and the upper low concentration mixture 119d is ejected from the lower mixture jetting portion of the super-rich A / C mixture nozzle 114a.

As a result, it is expected that the rich flame 19a formed by the high-concentration air-fuel mixture 119c blown from the upper air-fuel mixture ejection section will have excellent ignition stability. The anti-swirl body 125 is provided at the bottom of the super-rich A / C jet nozzle pipe 114b, and the high-concentration air-fuel mixture 119c from the lower air-fuel mixture jet part of the super-rich A / C air-fuel mixture nozzle 114a and the upper air-fuel mixture jet part from the upper air-fuel jet section. It is also possible to eject the low concentration mixture 119d. The structure of the light-and-light divided body 128 is not limited to the above-described structure, and any structure may be adopted as long as the high-concentration mixture 119c and the low-concentration mixture 119d can be vertically separated.

Therefore, according to the third embodiment, the first
In addition to the basic effects of the embodiment, a highly concentrated air-fuel mixture
9c can be ejected from the upper air-fuel mixture jetting portion of the super-rich A / C air-fuel mixture nozzle 114a, so that the rich flame 19a formed by the high-concentration air-fuel mixture 119c blown from the upper air-fuel mixture jetting portion has stable ignition. Can be enhanced.

[0051]

As described above, according to the first aspect of the present invention, the concentration of the fine fuel mixture can be adjusted by adjusting the blowing speed by the speed adjusting damper. When the concentration of the fine fuel mixture is increased, for example, the flow rate is increased by adjusting the direction of the inlet by using a speed adjusting damper, and when the concentration of the fine fuel mixture is reduced, the inlet is opened by, for example, the speed adjusting damper. This can be done by adjusting the direction and reducing the flow rate. Therefore, even when the solid fuel is pulverized and supplied directly to the burner nozzle, there is an effect that the concentration of the pulverized fuel mixture is optimally adjusted and the primary air / fuel ratio can be burned in an optimal state.

According to the second aspect of the present invention, it is possible to use a pulverized fuel mixture obtained by pulverizing a solid fuel, for example, coal, as it is. This eliminates the need for a device, thereby greatly reducing equipment costs, and has the effect of reducing the size of the device.

According to the third aspect of the present invention, by adjusting the position of the air-fuel mixture discharge nozzle pipe by the position adjusting operation device, for example, when the air-fuel mixture discharge nozzle pipe is inserted in the injection direction of the nozzle pipe. The concentration of the exhaust air-fuel mixture increases, and when the air-fuel mixture is pulled out in the opposite direction, the concentration of the exhaust air-fuel mixture decreases. This makes it possible to adjust the concentration of the high-concentration pulverized fuel mixture ejected from the nozzle pipe, so that the primary air / fuel There is an effect that combustion can be performed in an optimum ratio.

According to the fourth aspect of the present invention, it is possible to adjust the concentration of the high-concentration pulverized fuel mixture ejected from the nozzle pipe by using the same together with the position adjusting operation device. There is an effect that the fuel can be burned in an optimum fuel / fuel ratio. According to the fifth aspect of the present invention, it is possible to increase the concentration of the pulverized fuel-fuel mixture on the outer surface side of the flame, so that the ignition stability can be improved.

According to the sixth aspect of the present invention, it is possible to increase the concentration of the pulverized fuel / fuel mixture at one side of the flame, so that the ignition stability at this portion can be improved. . According to the seventh aspect of the present invention, the ignition distance can be shortened even in the case of a pulverized fuel mixture having a low volatile component, so that the ignition stability can be improved.

According to the eighth aspect of the present invention, since efficient heating can be achieved by stable combustion of the pulverized fuel combustion burner, there is an effect that an efficient and stable operation can be realized. According to the ninth aspect of the present invention, the concentration of the pulverized fuel-fuel mixture immediately before combustion can be directly operated, so that there is an effect that the adjustment accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is an overall system diagram of a first embodiment of the present invention.

FIG. 2 is an assembled sectional view of a burner-like box according to the first embodiment of the present invention.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is a view as viewed in the direction of arrow aa in FIG. 3;

FIG. 5 is a cross-sectional view near a speed adjustment damper.

FIG. 6 is a sectional view corresponding to FIG. 3 of a second embodiment of the present invention.

FIG. 7 is a sectional view taken along line bb of FIG. 6;

8 is a view as viewed in the direction of the arrows c-c in FIG.

FIG. 9 is a sectional view corresponding to FIG. 3 of a third embodiment of the present invention.

FIG. 10 is a sectional view taken along line dd of FIG. 9;

FIG. 11 is a view as seen in the direction of the arrow ee in FIG. 9;

FIG. 12 is a graph showing a relationship between an ignition distance and A / C.

FIG. 13 is an overall system diagram of the related art.

FIG. 14 is a sectional view of a conventional burner-like box.

[Explanation of symbols]

9 Pulverized coal transport line (pulverized fuel supply pipe) 14 Ultra-rich A / C mixture compartment (burner nozzle) 114b Ultra-rich A / C mixture nozzle pipe (nozzle pipe) 114c Mixture exhaust nozzle pipe (mixture discharge nozzle pipe) 114d Flow control damper (flow control device) 15 Ultra lean A / C mixture compartment (burner nozzle) 16 Auxiliary air compartment (burner nozzle) 117 Ultra lean A / C mixture line (supply route) 124 Speed adjusting damper 126 Mixture discharge pipe Operating device (operating device for position adjustment) 127 Light / dark separation body 128 Light / dark separation body

Continued on the front page (72) Inventor Akiyasu Okamoto 5-717-1, Fukahori-cho, Nagasaki-shi, Nagasaki Pref. In the Nagasaki Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Masaharu Oguri 5-717-1, Fukahori-cho, Nagasaki-shi, Nagasaki F term (reference) in Nagaishi Engineering Co., Ltd. 3K065 QA03 QB10 QC03 3K091 AA20 BB02 BB25 CC13 DD01 DD08

Claims (9)

[Claims] 1. A pulverized solid fuel is mixed with air or another gas, and a pulverized fuel supply pipe for supplying the pulverized fuel mixture is provided. A pulverized fuel mixture supplied from each of the pulverized fuel supply pipes is provided. And a plurality of burner nozzles for injecting a high-concentration pulverized fuel mixture in a pulverized-fuel combustion burner configured to be able to individually inject a plurality of types of pulverized fuel mixture having different concentrations to be supplied. Speed adjustment that blows the supplied pulverized fuel mixture tangentially to the cross section of the nozzle pipe of the burner nozzle near the connection between the burner nozzle that blows air and the pulverized fuel supply pipe, and adjusts the blowing speed A pulverized fuel combustion burner comprising a damper. 2. The pulverized fuel combustion burner according to claim 1, wherein the solid fuel has a fuel ratio (fixed carbon content / volatile content) of 2 or more or a volatile content of 10% or less. 3. The nozzle pipe of the burner nozzle for ejecting the high-concentration pulverized fuel air-fuel mixture is opened in the nozzle pipe to suck a part of the pulverized fuel-air mixture, thereby adjusting the concentration of the air-fuel mixture in the nozzle pipe and suctioning the same. A mixture discharge nozzle pipe for supplying the burned fine-fuel mixture to another burner nozzle is provided, and the mixture discharge nozzle pipe is provided with a position adjusting operation device for adjusting an insertion position into the nozzle pipe. The pulverized fuel combustion burner according to claim 1 or 2, characterized in that: 4. A flow control device is provided in a supply path between the mixture discharge nozzle pipe and another nozzle pipe for burning the fine fuel mixture discharged by the mixture discharge nozzle pipe. The burner according to claim 3, characterized in that: 5. A nozzle pipe of a burner nozzle for ejecting the high-concentration pulverized fuel / fuel mixture, wherein a high-concentration pulverized-fuel mixture is formed around the outer periphery of the fine-powder-fuel mixture ejected from the nozzle pipe. The pulverized fuel combustion burner according to any one of claims 1 to 3, wherein a separator is provided. 6. A high-concentration air-fuel mixture and a low-concentration air-fuel mixture are separately ejected from a nozzle pipe of a burner nozzle for jetting the high-concentration pulverized fuel air-fuel mixture by dividing the air-fuel mixture jetting portion of the nozzle pipe into two parts. The burner according to any one of claims 1 to 3, wherein a possible light and shade divided body is provided. 7. The fine powder according to claim 1, wherein the primary air / fuel weight ratio of the high-concentration fine fuel mixture is set to 0.75 to 1.25. Fuel burner. 8. The method according to claim 1, wherein the burner nozzles are installed in a plurality of stages in the vertical direction on each wall surface or each corner portion of the furnace.
And a pulverized fuel combustion burner according to any one of claims 7 to 7, wherein the pulverized fuel mixture supplied to each burner nozzle is blown in a tangential direction to a virtual circle set at a substantially central portion of a furnace cross section to perform swirling combustion. Boiler characterized by performing. 9. Finely pulverized solid fuel is mixed with air or other gas, and this finely divided fuel is separated into finely divided fuels having different concentrations. The low-concentration portion of the high-concentration pulverized fuel mixture supplied to the burner nozzle for the air-fuel mixture is sucked and supplied to the burner nozzle for the low-concentration pulverized fuel mixture. A pulverized fuel combustion method characterized in that the pulverized fuel is burned with the concentration of the pulverized fuel mixture adjusted.