JPH11264509A - Coal fired combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the inflow of a fuel into a space in a coal fired combustion device where a primary side passage that communicates with a fuel pipe is formed inside and a secondary side passage that communicates with a wind box is formed outside and the primary side passage is branched into upper and lower portions and at the same time the space that communicates with the above secondary side passage is formed between them. SOLUTION: A primary side passage 5 that communicates with a combustion pipe 2 is formed inside a burner nozzle 3, a secondary side passage 6 that communicates with a wind box 1 is formed outside, the primary side passage 5 is divided into supper and lower portions, and at the same time a space 7 that communicates with the secondary side passage 6 is formed between them. A separation prevention structure 16 where a central part in a width direction has a loner shape in the direction of a burner shaft is arranged in the space 7 between the primary side passages 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coal-fired combustion apparatus applied to a power boiler and the like.

[0002]

2. Description of the Related Art An example of a conventional coal-fired combustion apparatus is shown in FIGS. This combustion device comprises a wind box 1, a fuel pipe 2,
And the burner nozzle 3. In the burner nozzle 3, an inner primary passage 5 and an outer secondary passage 6 are formed by a partition wall 4. Primary passage 5
The center is further branched up and down by a space 7, and the space 7 communicates with the secondary passage 6 described above.

The coal-fired combustion apparatus shown in FIGS. 7 and 8 has the above-described configuration. A mixture 9 of pulverized coal fuel and carrier air is supplied from a fuel pipe 2, and combustion air 10 is supplied to a wind box 1. And the fuel pipe 2 flows into the burner nozzle 3. The mixture 9 of fuel and carrier air forms a flow 11 passing through the primary passage 5 of the burner nozzle 3, and the combustion air 10 forms a flow 12 passing through the secondary passage 6 of the burner nozzle 3. Burns.

A part of the flow 12 of the combustion air passing through the secondary passage 6 of the burner nozzle 3 becomes a flow 13 of the combustion air passing through the space 7. Due to this flow 13, FIG.
As shown in FIG. This swirl flow 14
In the central part between the space 7 and the furnace 8 due to the influence of the above, a region where the pressure is lower than the surroundings is generated, and the mixture of the fuel and the carrier air passing through the primary passage 5 is partially discharged by the flow 11 passing through the primary passage. As shown in FIG.
The fuel flows back inside. When the fuel stays in the combustion apparatus in this way, the fuel burns due to radiant heat from the high-temperature furnace 8, and the burner nozzle 3 may be deformed by the heat.

[0005]

According to the present invention, as described above, a primary side passage communicating with the fuel pipe is formed on the inside, and a secondary side passage communicating with the wind box is formed on the outside. Provided is a coal-fired combustion device in which a space that is branched into two and communicates with the secondary-side passage is formed therebetween, so that fuel can be prevented from flowing into the space. That is the task.

[0006]

According to the present invention, in order to solve the above-mentioned problems, a central portion in a width direction is provided in a space formed between a primary side passage branched into upper and lower portions in a burner axial direction. Provided is a coal-fired combustion device having a configuration in which a long separation prevention structure is arranged.

In the coal-fired combustion device according to the present invention,
Since the separation preventing structure having the above-described configuration is arranged in the space between the branched primary passages, the combustion air flowing into the space from the secondary passage is separated from the separation preventing structure. Flows smoothly along the outline of.

[0008] Therefore, the combustion air flowing into this space is not separated or very weak if it does. Therefore, the inflow of the fuel and the carrier air from the primary passage into the space is suppressed, and the deformation of the burner nozzle due to the combustion of the retained fuel can be prevented.

According to another aspect of the present invention, there is provided a fuel cell system, wherein one end is located in a secondary passage, and the other end is located in a space formed between the upper and lower branched primary passages. And a coal-fired combustion apparatus having a configuration in which a guide plate for guiding air from a secondary side passage into the space is provided.

In the thus constructed coal-fired combustion apparatus of the present invention, since the combustion air smoothly flows from the secondary passage to the space between the primary passages along the guide plate, the combustion air flows from the space to the furnace. The fuel is discharged at a high flow rate, and the backflow of the fuel and the carrier air, which are going to flow into the space from the primary passage, is suppressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A coal-fired combustion apparatus according to the present invention will be specifically described below with reference to the embodiments shown in FIGS. In the following embodiments, the same components as those of the conventional apparatus shown in FIGS. 7 and 8 are denoted by the same reference numerals for the sake of simplicity.

(First Embodiment) First, a coal-fired combustion apparatus according to a first embodiment shown in FIGS. 1 to 3 will be described. The coal-fired combustion apparatus according to the first embodiment is such that the burner nozzle 3 is divided into an inner primary side passage 5 and an outer secondary side passage 6 by a partition 4, and the inner primary side passage 5 is further branched up and down. The point that the space 7 therebetween communicates with the outer secondary side passage 6 is the same as the conventional one described above.

However, in the coal-fired combustion apparatus according to the present embodiment, a separation preventing structure 16 having a shape whose central portion in the width direction is long in the burner axis direction is provided in the space 7. The structure of the peeling prevention structure 16 is as shown in FIG.
The ratio between the width L and the axial length L1 shown in FIG. 2 is L1 = L / 2 as an example.

As described above, the coal-fired combustion apparatus according to the present embodiment is the same as the apparatus shown in FIGS. 7 and 8 except that the separation preventing structure 16 is disposed in the space 7.

In the coal-fired combustion apparatus of this embodiment, the mixture 9 of fuel and carrier air is supplied from the fuel pipe 2 to the combustion air 1.
0 flows into the burner nozzle 3 from the space between the wind box and the fuel pipe 2, and the mixture 9 of fuel and carrier air flows into the burner nozzle 3.
After the primary passage 5 and the combustion air 10 flow through the secondary passage 6 and the space 7 of the burner nozzle 3 to the furnace 8, the fuel is burned.

The combustion air flowing into the combustor from between the wind box 1 and the fuel pipe 2 flows into the furnace 8 via the secondary passage 6 of the burner nozzle 3, and a part of the combustion air flows between the primary passage 5. Pass through the space 7. At this time, in the conventional configuration, as described above, since the flow path is a sudden expansion from the secondary side passage 6 to the space including the space 7, the flow is separated, and the swirl flow 1
As a result, the pressure at the center of the furnace-side opening of the space 7 is lower than the surroundings, and a part of the flow 11 through the primary passage 5 through which the mixture 9 of fuel and carrier air flows to the furnace 8 It was designed to flow back into 7.

However, in the apparatus of the present embodiment, there is a peel prevention structure 16 having a long length in the burner axis direction at the central portion in the width direction in the space 7, and as shown in FIG. Since the flow 13 of the working air flows, separation of the flow does not occur or becomes very weak. As a result, the pressure difference between the vicinity of the center in the width direction of the opening on the furnace side of the space 7 and the surrounding area is reduced, and the flow 11 of the mixture 9 of the fuel and the carrier air passing through the primary side passage is changed to the flow 15 flowing back to the space 7. And the deformation of the burner nozzle 3 due to the combustion of the stagnant fuel can be prevented.

(Second Embodiment) Next, a coal-fired combustion apparatus according to a second embodiment shown in FIGS. 4 to 6 will be described. In the coal-fired combustion device according to the second embodiment, the first
The peel prevention structure 16 employed in the embodiment is omitted, and a guide plate 17 is provided instead.

That is, the guide plate 17 has the shape shown in FIG. 6, and has one end located in the secondary passage 6, bent in the secondary passage 6, and the other end located in the space 7. Placed in Other configurations are substantially the same as those of the coal-fired combustion device according to the first embodiment.

In the coal-fired combustion apparatus according to the second embodiment having the above structure, the combustion air 10 has a guide plate 1 having one end in the secondary passage 6 and the other end in the space 7.
Since the air flows into the space 7 along the inside of the space 7, the flow velocity of the flow 13 of the combustion air flowing out from the vicinity of the center in the width direction of the space 7 to the furnace 8 is increased, as in the device of the first embodiment.
The flow 11 of the mixture 9 of the fuel and the carrier air flowing through the primary side passage 5 is suppressed from flowing back to the space 7, and the deformation of the burner nozzle 3 due to the combustion of the retained fuel can be prevented.

[0021]

As described above, the present invention relates to a coal-fired combustion apparatus comprising a wind box in which a fuel pipe through which coal is conveyed is provided, and a burner nozzle disposed at the tip of the wind box. In the burner nozzle, a primary side passage communicating with the fuel pipe is formed on the inside, and a secondary side passage communicating with the wind box is formed on the outside. In a space in which a space communicated with a secondary passage is formed, a coal-fired structure in which a separation preventing structure having a shape in which a central portion in a width direction is elongated in a burner axial direction is arranged in the space between the primary passages. A combustion device is provided.

According to this combustion device, the combustion air flowing from the secondary passage into the space between the primary passages is guided smoothly along the outer shape of the separation preventing structure. Therefore, the inflow of fuel and carrier air from the primary side passage into the space is suppressed.

Further, instead of the peeling prevention structure, one end is in the secondary passage and the other end is in the space between the primary passages, and the air from the secondary passage is supplied to the space. In the coal-fired combustion device of the present invention in which a guide plate that guides the
Since the combustion air flows smoothly from the secondary passage along the guide plate into the space between the primary passages, the velocity of the combustion air flow flowing out of the vicinity of the center of the burner nozzle into the furnace increases, and this space is increased. Backflow of fuel from the primary passage is suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a coal-fired combustion device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a perspective view of a peeling prevention structure.

FIG. 4 is a sectional view of a coal-fired combustion device according to a second embodiment of the present invention.

FIG. 5 is a sectional view taken along the line VV in FIG. 4;

6 (a) is a plan view, FIG. 6 (b) is a side view, and FIG. 6 (c) is a right side view of FIG. 6 (b).

FIG. 7 is a sectional view of a conventional coal-fired combustion device.

FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wind box 2 Fuel pipe 3 Burner nozzle 4 Partition wall 5 Primary passage 6 Secondary passage 7 Space 8 Furnace 9 Mixture of fuel and carrier air 10 Combustion air 11 Flow through primary passage 12 Flow through secondary passage 13 Combustion air flow 14 Swirling flow 15 Reverse flow 16 Separation prevention structure 17 Guide plate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tokuo Miyazaki 1-1-1, Akunouramachi, Nagasaki Mitsubishi Heavy Industries, Ltd. Inside Nagasaki Shipyard (72) Inventor Toshimitsu Ichinose 5-717-1, Fukahoricho, Nagasaki-shi Mitsubishi Heavy Industries, Ltd. Nagasaki Research Laboratory

Claims (2)

[Claims] 1. A coal-fired combustion apparatus comprising: a wind box in which a fuel pipe through which coal is conveyed is provided; and a burner nozzle disposed at the tip of the wind box. A primary-side passage communicating with the pipe, a secondary-side passage communicating with the wind box is formed outside, and the primary-side passage is branched into two upper and lower portions, and a space communicated with the secondary-side passage therebetween. A coal-fired combustion apparatus, wherein a separation prevention structure having a central portion in a width direction having a shape elongated in a burner axis direction is disposed in the space between the primary side passages. 2. A coal-fired combustion apparatus comprising: a wind box in which a fuel pipe through which coal is conveyed is provided; and a burner nozzle disposed at the tip of the wind box. A primary passage that communicates with a pipe, a secondary passage that is communicated with the wind box outside is formed, and the primary passage is branched into upper and lower two portions, and a space that communicates with the secondary passage therebetween. A guide plate having one end in the secondary passage and the other end in the space between the primary passages and guiding air from the secondary passage to the space. A coal-fired combustion device characterized by the following.