JPH10332110A - Pulverized coal burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the distribution of the concentration of pulverized coal, which is set in a pulverized coal nozzle tube, from becoming abnormal, even in the case where a pulverized coal nozzle is vertically inclined in a pulverized coal burner having the pulverized coal nozzle provided in a swingable manner, in the vicinity of a top end of the pulverized coal nozzle tube for leading a mixture of the pulverized coal with transfer air to a burner. SOLUTION: This burner has a pulverized coal nozzle 104 disposed in a swingable manner by a nozzle driving shaft 118 in the vicinity of a top end of a pulverized coal nozzle tube 106. A pulverized coal concentration adjusting body 120 is mounted in the pulverized coal nozzle 104. The pulverized coal concentration adjusting body 120 is provided at its center with a coal-air mixture passage 121 and, further, a contracted flow passage 122 is formed between an outer peripheral face of the coal-air mixture passage 121 and an inner peripheral face of the pulverized coal nozzle 104. Concentration distribution is given to a coal-air mixture to be supplied from the pulverized coal nozzle 104, so that the concentration of the pulverized coal on the surface side of the coal-air mixture is made high while the concentration of the pulverized coal on the inner side of it is made low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulverized coal burner suitable for use in a pulverized coal-fired boiler for generating steam for power generation or for factories.

[0002]

2. Description of the Related Art A conventional pulverized coal burner used in a pulverized coal fired boiler will be described with reference to FIGS. FIG. 5 shows an example of the structure of a conventional pulverized coal-fired boiler, and FIG. 6 shows the structure of a pulverized coal burner used therein. In these figures, reference numeral 14 denotes a furnace wall of a boiler, in which a furnace 13 is formed. Furnace wall 14
Is equipped with a pulverized coal burner.

[0003] 01 is a burner-like box, 02 is a fuel air compartment, and 03 is an auxiliary air compartment. Reference numeral 04 denotes a pulverized coal nozzle, around which an auxiliary air nozzle 05 is arranged. The pulverized coal nozzle 04 is connected to a pulverized coal nozzle pipe 06.

[0004] A pulverized coal mixture transport pipe 07 to which a pulverized coal mixture is supplied is connected to the pulverized coal nozzle pipe 06.
Reference numeral 08 denotes a fuel air duct to which the combustion air 10 is supplied. An evaporating tube 15 is provided above the furnace 13.

[0005] The pulverized coal burner has a pulverized coal nozzle 04 and an auxiliary air nozzle 05. Reference numeral 19 denotes a nozzle operation rod, and a pulverized coal concentration adjuster 20 is arranged in the pulverized coal nozzle pipe 06.

In the pulverized coal-fired boiler having the above-described structure shown in FIGS. 5 and 6, coal fed to a coal pulverizer (not shown) is pulverized and mixed with carrier air (warm air) fed at the same time. To form a pulverized coal mixture 09, which is sent to a pulverized coal nozzle pipe 06 attached to a burner-like box 01 through a pulverized coal mixture transport pipe 07, and a pulverized coal nozzle 04.
From the furnace 13.

On the other hand, the combustion air 10 is supplied from a blower (not shown) through a combustion air duct 08 to a burner wind box 0.
It is sent to 1. The interior of the burner-like box 01 is partitioned into three stages, the center of which is a fuel air compartment 02, and the upper and lower stages thereof are auxiliary air compartments 03.

The combustion air 10 sent to the burner wind box 01 is divided into the main combustion air 11 sent to the fuel air compartment 02 and the auxiliary air 12 sent to the auxiliary air compartment 03 in the burner wind box 01. Is done.

A pulverized coal nozzle 04 is mounted at the outlet of the fuel air compartment 02. In the center of the pulverized coal nozzle 04, an ejection hole for pulverized coal mixture 09 is provided.
An ejection hole for the main combustion air 11 is provided around the outside of the ejection hole.

[0010] The pulverized coal mixture 09 is led to the outlet of the pulverized coal mixture 09 from a pulverized coal nozzle pipe 06 communicating with a pulverized coal mixture transport pipe 07 outside the burner-like box 01. In the pulverized coal nozzle pipe 06, a pulverized coal concentration controller 20 is mounted.

An air-fuel mixture passage 21 is provided at the center of the pulverized coal concentration controller 20. The outer shape of the pulverized coal concentration regulator 20 has a small upstream diameter, and has a maximum diameter substantially in the middle of the body, and some of the outer diameter are parallel to the other end and narrower and reach the other end.

The pulverized coal mixture 09 sent into the pulverized coal nozzle tube 06 is supplied from the mixture passage 21 to the gap between the outer surface of the pulverized coal concentration regulator 20 and the inner wall surface of the pulverized coal nozzle tube 06. Is fed into the pulverized coal nozzle 04 from the contraction passage 22 formed therein, and is blown into the furnace 13 through the ejection hole of the pulverized coal mixture 09.

When the pulverized coal mixture 09 passes through the contraction passage 22, the pulverized coal is concentrated on the inner wall side of the pulverized coal nozzle tube 06 by inertia force. The pulverized coal concentration on the surface side of the air-fuel mixture 09 becomes higher and the inner side becomes lighter. As a result, the surface side of the pulverized coal mixture 09 receives radiant heat from inside the furnace 13, so that volatile components in the pulverized coal are generated and ignition is facilitated.

The main combustion air 11 sent into the fuel air compartment 02 is blown into the furnace 13 from the outlet of the main combustion air 11 of the pulverized coal nozzle 04.

The auxiliary air compartment 03 is provided with an auxiliary air nozzle 05 at the outlet thereof, and the supplied auxiliary air 12 is supplied from the auxiliary air nozzle 05 to the furnace 1.
It is blown into 3.

The pulverized coal mixture 09 blown into the furnace 13
Is ignited by an ignition source (not shown), and pulverized coal flame 1
6, the combustion gas 17 rises in the furnace 13 while continuing combustion by the main combustion air 11 and the auxiliary air 12, but the combustion is substantially completed at the inlet of the evaporating tube 15 group.

Combustion gas 1 generated by the combustion of pulverized coal
Heat is absorbed by the furnace wall 14 constituting the heat transfer surface, and the temperature of the furnace 7 decreases as the inside of the furnace 13 rises.

Pulverized coal nozzle 04 and auxiliary air nozzle 05
Is supported on the wall surfaces of the compartments 02 and 03 by a nozzle driving shaft 18 so as to be rotatable up and down. Further, both nozzles 04 and 05 are provided with nozzle operating rods 19 so that the burner-like box 01 By operating the nozzle operating rod 19, the pulverized coal nozzle 04 and the auxiliary air nozzle 05 are adjusted so that the respective ejection holes face up and down with the nozzle driving shaft 18 as a fulcrum.

As described above, in the conventional pulverized coal burner, when it becomes necessary to increase the temperature of the combustion gas 17 at the inlet of the evaporating pipe group 15, the combustion area is increased by directing the ejection holes of the nozzles 04 and 05 upward. Conversely, when it is necessary to reduce the temperature, the ejection holes of the nozzles 04 and 05 are directed downward.

[0020]

When such a pulverized coal nozzle 04 is turned up and down, the pulverized coal nozzle tube 0
Since the pulverized coal concentration on the surface side of the pulverized coal mixture 09 formed in 6 is high and the pulverized coal concentration distribution in which the inside is lightened collapses in the pulverized coal nozzle 04, the ignition stability of the pulverized coal flame 16 is impaired. Had the disadvantage that

The present invention relates to a pulverized coal burner in which a pulverized coal nozzle is swingably provided near the tip of a pulverized coal nozzle pipe for guiding a mixture of pulverized coal and carrier air to a burner. It is an object of the present invention to provide a pulverized coal burner configured so that the pulverized coal concentration distribution formed in the pulverized coal nozzle pipe is not collapsed even when the pulverized coal nozzle pipe is inclined in the vertical direction.

[0022]

According to the present invention, in order to solve the above-mentioned problems, a pulverized coal concentration regulator is mounted in the pulverized coal nozzle, which is swingably disposed near the tip of a pulverized coal nozzle pipe. I do.

As described above, in the pulverized coal burner according to the present invention, by installing the pulverized coal concentration controller in the pulverized coal nozzle, the pulverized coal mixture at the outlet of the pulverized coal nozzle even when the pulverized coal nozzle is vertically inclined. Can be formed such that the surface side of the pulverized coal mixture is always thicker and the inner side is thinner.

Further, the present invention provides a pulverized coal nozzle pipe for guiding a mixture of pulverized coal and carrier air to a burner, and a pulverized coal nozzle which is swingably disposed near the tip of the pulverized coal nozzle pipe. In order to solve the above-mentioned problems in the pulverized coal burner equipped with a pulverized coal nozzle, a pulverized coal concentration adjuster is mounted inside the pulverized coal nozzle pipe, and a pulverized coal distribution plate is provided at the tip of the pulverized coal nozzle pipe. A pulverized coal burner provided with a pulverized coal guide plate in a nozzle.

According to the pulverized coal burner of the present invention, the surface of the pulverized coal mixture becomes concentrated at the outlet and the concentration of the pulverized coal at the inner side at the outlet by the pulverized coal concentration regulator in the pulverized coal nozzle tube. The concentration distribution of the pulverized coal mixture thus formed can be kept almost unchanged at the outlet of the pulverized coal nozzle by the pulverized coal distribution plate and the pulverized coal guide plate even if the pulverized coal nozzle is vertically inclined. is there.

As described above, according to the pulverized coal burner of the present invention, even if the pulverized coal nozzle is swung, the predetermined pulverized coal concentration distribution is not collapsed, and the pulverized coal flame has stable ignitability and is always excellent in pulverized coal flame Can be formed.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pulverized coal burner according to the present invention will be specifically described below with reference to the embodiment shown in FIGS.

(First Embodiment) First, a pulverized coal burner according to a first embodiment shown in FIGS. 1, 2 and 3 will be described. FIGS. 1, 2 and 3 show only the pulverized coal nozzle pipe and the pulverized coal nozzle to be mounted in the fuel air compartment 02 of the burner-like box shown in FIGS. The other parts have substantially the same structure and operation as the conventional pulverized coal burner.

1, 2 and 3, reference numeral 101 denotes a burner wind box, 102 denotes a fuel air compartment,
3 indicates an auxiliary air compartment. Reference numeral 104 denotes a pulverized coal nozzle which is vertically rotatably mounted on a nozzle driving shaft 118. Reference numeral 106 denotes a pulverized coal nozzle pipe for guiding a pulverized coal mixture 109. 111 is a main combustion air, and 113 is a furnace. 119 is a nozzle operation rod, and 120 is a pulverized coal concentration regulator.

In the pulverized coal burner shown in FIGS. 1, 2 and 3, a pulverized coal mixture 109 sent from a coal pulverizing facility (not shown) is sent from a pulverized coal nozzle tube 106 to a pulverized coal nozzle 104. .

The pulverized coal nozzle 104 is provided with an ejection hole for pulverized coal mixture 109 at the center thereof, and an ejection hole for main combustion air 111 around the ejection hole. In the pulverized coal nozzle 104, a pulverized coal concentration regulator 120 is mounted at the center of the ejection hole of the pulverized coal mixture 109.

The pulverized coal concentration regulator 120 has an air-fuel mixture passage 121 opened at the center thereof. The outer shape of the pulverized coal concentration controller 120 has a small upstream diameter, a maximum diameter substantially in the middle, and parallel to the end as it is. Pulverized coal concentration regulator 120
Is formed between the outer surface of the nozzle and the inner wall surface of the pulverized coal nozzle pipe.

The pulverized coal mixture 109 sent to the pulverized coal nozzle 104 is supplied to a mixture passage 121 and a contraction passage 122.
Through the outlet of the pulverized coal mixture 109 into the furnace 113.

The pulverized coal mixture 109 sent through the mixture passage 121 has no change in the pulverized coal concentration at the inlet side and the outlet side. Since the pulverized coal is concentrated on the inner wall side of the pulverized coal nozzle 104 by inertia force when passing through the passage 122, the surface side of the pulverized coal mixture 109 at the outlet side of the pulverized coal concentration regulator 120 becomes the dense pulverized coal mixture 109a, The inside is a light pulverized coal mixture 109b.

The main combustion air 111 and the auxiliary air 112 operate in the same manner as the conventional air, so that the description is omitted.
Even when the pulverized coal nozzle 104 is turned up and down as shown in FIG. 3 by mounting the pulverized coal concentration controller 120 in the pulverized coal nozzle 104, the pulverized coal concentration formed at the outlet of the pulverized coal concentration controller 120 is adjusted. The distribution is constantly blown into the furnace 113 from the outlet of the pulverized coal mixture 109 without change.

As a result, the pulverized coal mixture 109 blown into the furnace 113 always has a high concentration of pulverized coal on the surface side, and thus receives radiant heat from the furnace 113 to generate volatile components in the pulverized coal. As the size becomes large, ignition becomes easy, and a stable pulverized coal flame having excellent ignition stability can be formed.

(Second Embodiment) Next, a pulverized coal burner according to a second embodiment shown in FIG. 4 will be described. In FIG. 4, reference numeral 123 denotes a pulverized coal distribution plate, which is provided at the tip of the pulverized coal nozzle tube 106.

Reference numeral 124 denotes a pulverized coal guide plate, which is mounted in the pulverized coal nozzle 104. Other configurations are shown in FIG.
3 are substantially the same as those in FIG. 3 and corresponding portions are denoted by the same reference numerals, and description thereof will be omitted.

In the pulverized coal burner according to the second embodiment, the pulverized coal mixture 109 sent from a coal pulverizing facility (not shown) reaches the pulverized coal nozzle tube 106.

A pulverized coal concentration control body 120 is provided in the pulverized coal nozzle pipe 106, and the pulverized coal nozzle pipe 106 is divided into upper, middle, and lower stages on the outlet side (the downstream side). The pulverized coal distribution plate 123 is mounted so as to extend to the outlet of the pulverized coal nozzle tube 106.

A pulverized coal nozzle 104 is provided at the outlet of the pulverized coal nozzle pipe 106, and the pulverized coal mixture 109 sent into the pulverized coal nozzle pipe 106 is blown into the furnace 113 for combustion. In the pulverized coal nozzle 104, a pulverized coal guide plate 124 is mounted so as to communicate with the pulverized coal distribution plate 123 in the pulverized coal nozzle tube 106.

The relative positions of the pulverized coal guide plate 124 and the pulverized coal distribution plate 123 are arranged so as to be always in contact even if the pulverized coal nozzle 104 operates in the vertical direction.

The pulverized coal mixture 109 sent into the pulverized coal nozzle tube 106 passes through a contraction passage 122 formed by the outer surface of the pulverized coal concentration regulator 120 and the inner wall surface of the pulverized coal nozzle tube 106. At this time, the pulverized coal is concentrated on the inner wall side of the pulverized coal nozzle tube 106 by the inertial force. It is a charcoal mixture 109b.

The pulverized coal mixture 109a is pulverized coal nozzle pipe 1 divided into upper, middle and lower three stages by a pulverized coal distribution plate 123 provided on the outlet side of pulverized coal concentration regulator 120.
The light pulverized coal mixture 109b is fed into the pulverized coal nozzle 104 from the upper and lower passages in the 06 and from the middle passage.

The mixture 109a, 109b of the mixture of fine and fine pulverized coal sent to the pulverized coal nozzle 104
While maintaining the pulverized coal concentration distribution at the outlet of the pulverized coal nozzle tube 106 by the pulverized coal guide plate 124 mounted inside,
It is blown into the furnace 113 from the pulverized coal nozzle 104 and provided for combustion.

Further, even when the pulverized coal nozzle 104 is rotated up and down around the nozzle driving shaft 118, the pulverized coal concentration distribution at the outlet of the pulverized coal nozzle 104 is controlled by the pulverized coal distribution plate 123 and the pulverized coal guide plate 124. Can be maintained as it is at the outlet portion of the pulverized coal nozzle tube 106, so that the pulverized coal flame 116 excellent in ignition stability can always be formed.

[0047]

As described above, in the pulverized coal burner according to the present invention, the pulverized coal concentration regulator is mounted in the pulverized coal nozzle, and according to this, the pulverized coal nozzle equipped with the pulverized coal concentration regulator is installed. , The pulverized coal concentration distribution of the pulverized coal mixture to be blown into the furnace can always be kept dark on the surface side and light on the inside side.

Further, according to the present invention, a pulverized coal concentration controller is mounted in the pulverized coal nozzle pipe, a pulverized coal distribution plate is provided at the tip of the pulverized coal nozzle pipe, and a pulverized coal guide plate is provided in the pulverized coal nozzle. In the configuration, the inside of the pulverized coal nozzle pipe is divided into a large number by the pulverized coal distribution plate, and the divided passage is continued by the pulverized coal guide plate in the pulverized coal nozzle, and the pulverized coal concentration distribution at the outlet of the pulverized coal nozzle pipe ( (The surface side is dark and the inside side is light) is always held up to the outlet of the pulverized coal nozzle.

As described above, according to the pulverized coal burner of the present invention, a desired pulverized coal concentration distribution can always be maintained at the outlet of the pulverized coal nozzle, so that stable ignitability and excellent combustion flame formation can be achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the structure of a pulverized coal nozzle and a pulverized coal nozzle pipe in a pulverized coal burner according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line aa of FIG. 1;

FIG. 3 is a vertical sectional view of the pulverized coal burner of FIG. 1 in a state where a pulverized coal nozzle is directed upward;

FIG. 4 is a longitudinal sectional view showing the structure of a pulverized coal nozzle and a pulverized coal nozzle pipe in a pulverized coal burner according to a second embodiment of the present invention.

FIG. 5 is an explanatory view showing the structure of a conventional pulverized coal-fired boiler.

6 is a vertical sectional view showing an example of a pulverized coal burner used in the pulverized coal-fired boiler of FIG.

[Explanation of symbols]

 01 Burner Wind Box 02 Fuel Air Compartment 03 Auxiliary Air Compartment 04 Pulverized Coal Nozzle 05 Auxiliary Air Nozzle 06 Pulverized Coal Nozzle Tube 07 Pulverized Coal Mixture Transport Pipe 08 Combustion Air Duct 09 Pulverized Coal Mixture 10 Combustion Air 11 Main Combustion Air 12 Auxiliary air 13 Furnace 14 Furnace wall 15 Evaporation tube 16 Pulverized coal flame 17 Combustion gas 18 Nozzle driving shaft 19 Nozzle operating rod 20 Pulverized coal concentration regulator 21 Mixture passage 22 Contraction passage 101 Burner wind box 102 Burning Air compartment 104 Pulverized coal nozzle 106 Pulverized coal nozzle tube 109 Pulverized coal mixture 109a Rich pulverized coal mixture 109b Light pulverized coal mixture 111 Main combustion air 112 Auxiliary air 113 Furnace 118 Nozzle driving shaft 119 Nozzle operating rod 120 Pulverized coal Concentration regulator 121 mixed Passage 122 reduced flow passage 123 pulverized coal flow dividing plate 124 pulverized coal guide plate

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Ichiji Yamada 1-1-1, Akunouramachi, Nagasaki City Inside Nagasaki Shipyard, Mitsubishi Heavy Industries, Ltd. (72) Inventor Masaharu Oguri 5-717-1, Fukahoricho, Nagasaki City Naganishi Engineer Ring Co., Ltd.

Claims (2)

[Claims] 1. A pulverized powder comprising: a pulverized coal nozzle pipe for guiding an air-fuel mixture of pulverized coal and carrier air to a burner; and a pulverized coal nozzle slidably disposed near a tip end of the pulverized coal nozzle pipe. A pulverized coal burner, wherein a pulverized coal concentration regulator is mounted in the pulverized coal nozzle. 2. A pulverized powder comprising: a pulverized coal nozzle pipe for guiding an air-fuel mixture of pulverized coal and carrier air to a burner; and a pulverized coal nozzle slidably disposed near a tip end of the pulverized coal nozzle pipe. In the coal burner, a pulverized coal concentration regulator is mounted in the pulverized coal nozzle pipe, a pulverized coal distribution plate is provided at a tip end of the pulverized coal nozzle pipe, and a pulverized coal guide plate is provided in the pulverized coal nozzle. A pulverized coal burner characterized by the following.