JP2003343801A - Air supply method and device for stoker type boiler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress generation of carbon monoxide and dioxins. <P>SOLUTION: In a stoker furnace 1 with a combustion chamber 2 formed over a stoker 6 and a wind box 7 positioned under the stoker 6, secondary air supply nozzles 9 disposed on both sidewalls 2d and 2e in a front region of the combustion chamber 2 are not opposed laterally, but columns of the secondary air supply nozzles 9 in sets of two columns of a plurality of secondary air supply nozzles 9 vertically arrayed at given intervals are staggered for longitudinally alternate positions. After RDF 13 fed onto the stoker 6 is combusted with primary air 5 supplied from the wind box 7, mixing/turbulence of combustion gas and secondary air 8 blown into the combustion chamber 2 staggeringly from the left and right is promoted in the combustion chamber 2 to improve a combustion state in a high temperature combustion zone. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stoker used for supplying combustion air to a combustion chamber in order to completely burn a waste fuel such as RDF on the stoker of a stoker type boiler after burning the fuel with primary air. TECHNICAL FIELD The present invention relates to an air supply method and device for a boiler.

[0002]

2. Description of the Related Art As an example of a stoker type boiler, for example, in the case of an RDF fired stoker type boiler, FIG.
As indicated by reference numeral I in (b), the front wall 2a
In the inner bottom portion of the combustion chamber 2 which has an inlet 3 for RDF (solidified fuel for refuse) 13 as a fuel and has a gas outlet 4 at a position between the ceiling wall 2c and the rear wall 2b, primary air 5 is supplied. A stoker (movable grate) 6 provided with a large number of air holes for introducing is slanted so that the rear side is lower than the front side, and the RDF 13 placed on the upper side of the stoker 6 is placed.
Can be sent in order from the front to the rear by operating the stoker 6 with a drive device (not shown), and the wind box 7 is installed at a lower position of the stoker 6, The primary air 5 is supplied above the stoker 6 through the air hole of the stoker 6, and further,
Left and right side walls 2d in the region near the front side of the combustion chamber 2
And 2e, a large number of air supply nozzles 9 for the secondary air 8 as combustion air are installed so as to face each other, and the left and right side walls 2d and 2e of the region near the rear side of the combustion chamber 2 are provided.
In addition, a large number of air supply nozzles 11 for the tertiary air 10 as combustion air are installed so as to face each other to configure the stoker furnace 1, and heat is provided on the upper side of the combustion chamber ceiling wall 2c of the stoker furnace 1. A smoke tube group 12 as an exchange section is placed, and the gas outlet 4 of the combustion chamber 2 is connected to the smoke tube group 12 for communication.

In FIG. 5 (a), 14 is a combustion gas, 1
Reference numeral 5 is an exhaust port, 16 is a partition wall installed at a position closer to the combustion chamber rear wall 2b than the tertiary air supply nozzle 11 of the stoker furnace 1 so as to project below the combustion chamber ceiling wall 2c,
After the combustion gas 14 generated in the combustion chamber 2 is once diverted to the lower portion of the combustion chamber 2 by the partition wall 16, the combustion chamber rear wall 2
It can be guided to the gas outlet 4 along the line b. Furthermore, 17 is an ash discharge port provided at the end of the bottom of the combustion chamber 2 on the rear wall 2b side, and the combustion ash of the RDF 13 is transferred to the ash discharge port 17 by the stoker 6 and accumulated and then discharged. Is done.

When operating the above-mentioned RDF-fired stoker type boiler I, the combustion chamber 2 is passed through the charging port 3 of the stoker furnace 1.
Put the RDF 13 on the inside of the stoker 6 and
Primary air 5 is supplied from the wind box 7 to the RDF 13 charged above through the air holes of the stoker 6 so that the primary combustion is performed on the stoker 6, and combustion including unburned components generated during this primary combustion is performed. The gas is further combusted (completely combusted) by the secondary air 8 supplied from the secondary air supply nozzle 9 in a region near the front side in the combustion chamber 2 to form a high temperature combustion region, thereby forming a high temperature combustion gas. 14 is generated, while the slag of the RDF 13 remaining on the stoker 6 is the tertiary air 1 supplied from the tertiary air supply nozzle 11.
It is made to burn after 0. Further, the high temperature combustion gas 14 generated in the combustion chamber 2 is introduced from the gas outlet 4 to the smoke tube group 12 for heat exchange to be used as a heat source for steam generation, and then the heat in the smoke tube group 12 is changed. Exhaust port 1 for combustion gas 14 that has been used for replacement and has decreased in temperature
It is designed to be discharged from No. 5.

The wind box 7 has a flow path (zone) 7 divided into an inlet side and an outlet side along the front-back direction of the stoker 6.
By providing a, it is possible to change the supply amount of the primary air 5 for each divided flow path 7a in accordance with the amount of the RDF 13 that is burned and changed while moving on the stoker 6 from the front side to the rear side. I am doing it.

At the time of burning the RDF 13 as described above,
In order to suppress the generation of carbon monoxide and dioxins, generally, combustion temperature (Temperature), residence time (Tim
e), 3T of mixing and stirring (Turbulence) is said to be important.

[0007]

However, in FIG.
In the case of a stoker-type boiler such as the conventional RDF-fired stoker-type boiler I shown in (a) and (b), FIG.
As shown in FIG. 2, the secondary air supply nozzles 9 provided on both the left and right side walls 2d and 2e of the combustion chamber 2 are installed so as to face each other, and the secondary air supply nozzles 9 Since the air 8 is blown so as to face each other, there is a possibility that mixing and stirring of the blown secondary air 8 and the combustion gas containing unburned matter may become insufficient, and in such a high temperature combustion region When the mixing / stirring of the secondary air 8 and the combustion gas becomes insufficient, the combustion temperature in the high temperature combustion region decreases,
There is a risk of generation of carbon monoxide and dioxins. Therefore, it has been desired to promote the mixing and agitation of the combustion gas and the secondary air 8 to be blown in the combustion chamber 2 to suppress the generation of carbon monoxide and the generation of dioxins.

Therefore, the present invention is intended to promote the mixing and stirring of the combustion air and the combustion gas in the combustion chamber and to suppress the generation of carbon monoxide and dioxins. It is an object of the present invention to provide an air supply method and apparatus for a stoker type boiler.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention allows the combustion air blown into the combustion chamber from the left and right side walls of the combustion chamber of the stoker type boiler without facing each other in the left-right direction. The air supply method of the stoker type boiler that blows in a staggered manner and the air supply nozzles on the left and right side walls of the combustion chamber of the stoker type boiler are staggered so that they do not oppose each other in the left and right direction. An air supply device for a stoker type boiler having a configuration in which it is arranged.

After the fuel introduced into the stoker-type boiler is primarily burned on the stoker, and when combustion air is blown into the combustion chamber from the air supply nozzle to further burn the fuel, the air supply nozzle causes the left and right sides of the combustion chamber. Since the side walls of the combustion chamber are staggered so that they do not face each other in a staggered manner, the combustion air blown from the air supply nozzle of one combustion chamber side wall and the combustion air blown from the air supply nozzle of the other combustion chamber side wall are blown. The combustion air that is blown into the combustion chamber is not disturbed, and therefore the combustion air that is blown from the respective air supply nozzles has a higher penetrating force inside the combustion chamber, and thus the combustion air inside the combustion chamber is increased. Mixing and stirring are promoted, and combustion efficiency is improved.

Further, on the side walls of the left and right combustion chambers, rows of vertically arranged air supply nozzles are provided in a staggered arrangement in the front-rear direction, or a plurality of rows are arranged in the vertical direction and the front-rear direction. A set of air supply nozzles or one air supply nozzle is arranged in a zigzag pattern so as to be staggered in the vertical direction and the front-back direction, or,
By arranging the rows of air supply nozzles arranged in the front-rear direction so as to be staggered in the vertical direction, the combustion air is opposed to each other from the air supply nozzles provided on the left and right side walls of the combustion chamber. It can be blown and supplied into the combustion chamber without being forced to do so.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 (a) and (b) show an embodiment of an air supply method and apparatus for a stoker type boiler according to the present invention, which is shown in FIGS. 5 (a) and (b). The figure shows a case where it is applied to the supply of secondary air as the working air, and a large number of air supply nozzles for the secondary air 8 are respectively provided on the left and right side walls 2d and 2e at the front side position of the combustion chamber 2 of the stoker furnace 1. 9 is replaced with the structure arrange | positioned so that it may mutually oppose in the left-right direction, The air supply nozzle 9 for the secondary air 8 may be provided in both the left and right side walls 2d and 2e of the combustion chamber 2.
The installation positions are shifted on the left side and the right side so as not to oppose each other in the left-right direction. That is, for example, as shown in FIGS. 1 (a) and (b), at a position closer to the front side of one side wall (left side) 2d that is on the side of the front side region forming the high temperature combustion region in the combustion chamber 2,
When two rows of one set of secondary air supply nozzles 9 in each of which a plurality of secondary air supply nozzles 9 are arranged in the vertical direction at required intervals are installed with a required gap in the front-back direction, the other (right side) )
A plurality of secondary air supply nozzles 9 are arranged at required intervals in the vertical direction at a position closer to the front side of the side wall 2e between the rows of the pair of secondary air supply nozzles 9 on the left side. The secondary air supply nozzles 9 provided in one of the side walls 2d and the other side wall 2e are provided so that each set of two rows of the secondary air supply nozzles 9 is installed.
Secondary air 8 supplied from the secondary air supply nozzle 9 provided in the
In the combustion chamber 2 without facing each other in the combustion chamber 2
Be able to blow into it.

In addition, the same components as those shown in FIGS. 5A and 5B are designated by the same reference numerals.

When operating the RDF-fired stoker-type boiler I having the air supply device for the secondary air 8 having the above-described structure, the RDF 13 is introduced into the combustion chamber 2 from the charging port 3 of the stoker furnace 1 as in the conventional case. , The RD
F13 is primarily combusted by the primary air 5 blown and supplied from the wind box 7 below through the air holes of the stoker 6 on the stoker 6, and the combustion gas containing unburned components generated at the time of this primary combustion is At a position closer to the front side of the combustion chamber 2, the secondary air 8 blown and supplied from the secondary air supply nozzle 9 completely combusts it to form a high temperature combustion region and at the same time form a high temperature combustion gas 14. At this time, the secondary air supply nozzles 9 provided on both the left and right side walls 2d and 2e of the combustion chamber 2 are provided so as to be staggered in the front-rear direction by two rows, and each of the left and right secondary walls is provided. The secondary air 8 separately blown into the combustion chamber 2 from the air supply nozzle 9 is blown into the combustion chamber 2 without being obstructed by the secondary air 8 blown from the opposite sides. Therefore, the penetrating force of the secondary air 8 blown into the combustion chamber 2 is increased as compared with the conventional case, and the secondary air 8 blown into the combustion chamber 2 is mixed with the combustion gas containing unburned components. The stirring is promoted to be sufficiently performed, the combustion state of the combustion gas in the high temperature combustion region is improved, and the generation of carbon monoxide and dioxins can be suppressed.

The high temperature combustion gas 14 generated in the combustion chamber 2 is guided to the smoke tube group 12 and used as a heat source for generating steam in the smoke tube group 12 as in the conventional case, and then discharged from the exhaust port 15. To be done. Further, the slag of the RDF 13 is post-combusted by the tertiary air 10 from the tertiary air supply nozzle 11 as in the conventional case, and then the combustion ash is transferred to the ash discharge port 17.

Thus, according to the present invention, the stoker 6
The RDF 13 above is combusted by the primary air 5, and the combustion gas is promoted to be mixed and stirred with the secondary air 8 in the combustion chamber 2, so that the combustion state of the combustion gas in the high temperature combustion region can be improved. It becomes possible to suppress the generation of carbon oxide and the generation of dioxins.

Next, FIG. 2 shows another embodiment of the present invention, in which a high temperature combustion zone is formed in the combustion chamber 2 in the same construction as shown in FIGS. A configuration in which secondary air supply nozzles 9 arranged in the up-down direction are provided as a set of two rows in a staggered arrangement in the front-rear direction on both left and right side walls 2d, 2e of the combustion chamber 2 that are lateral to the front region. Instead of the above, a plurality of secondary air supply nozzles 9 arranged in the vertical direction and the front-back direction are set as one set (in the figure, four secondary air supply nozzles, two in the vertical direction and four in the front-back direction). 9 is shown as one set), one side wall 2d is provided with the set of secondary air supply nozzles 9 arranged in a staggered manner, and the other side wall 2e is shown by a two-dot chain line in FIG. The pair of secondary air supply nozzles 9 arranged on the one side wall 2d as described above. So that the arrangement of those which is adapted to arrange the set of the secondary air supply nozzles 9.

Other configurations are the same as those shown in FIGS. 1A and 1B, and the same components are designated by the same reference numerals.

Also according to the present embodiment, the secondary air 8 is respectively supplied from the secondary air supply nozzles 9 provided on the left and right side walls 2d and 2e of the combustion chamber without facing each other.
Which can be blown into the combustion chamber 2 for the secondary air 8
Since it is possible to increase the penetration force inside, Fig. 1 (a)
The same effect as that of the embodiment shown in (b) can be obtained.

Next, FIG. 3 shows still another embodiment of the present invention. In the same configuration as shown in FIG.
Secondary air supply nozzles 9 are provided on the left and right side walls 2d and 2e.
Instead of arranging a plurality of sets as staggered so that they do not face each other in the left-right direction, one secondary air supply nozzle 9 does not face each other in the left-right direction. They are arranged in a staggered manner so that they are staggered. Other configurations are the same as those shown in FIG. 2, and the same components are designated by the same reference numerals.

Also according to this embodiment, the secondary air supply nozzles 9 provided on the left and right combustion chamber side walls 2d and 2e, respectively.
Therefore, since the secondary air 8 can be blown into the combustion chamber 2 without being opposed to each other, the same effect as that of the embodiment shown in FIGS. 1A and 1B can be obtained.

Further, FIG. 4 shows still another embodiment of the present invention. Combustion which is lateral to the front region of the combustion chamber 2 in the same configuration as shown in FIGS. 1 (a) and 1 (b). On each of the left and right side walls 2d and 2e of the chamber 2, a plurality of secondary air supply nozzles 9 are vertically arranged at required intervals, and two rows of one set of secondary air supply nozzles 9 are staggered in the front-rear direction. Instead of providing the above configuration, a plurality of secondary air supply nozzles 9 are arranged in the front-rear direction on both left and right side walls 2d and 2e of the combustion chamber 2 in a row in a row. The rows of the next air supply nozzles 9 are provided such that their positions are shifted so that they are staggered in the vertical direction. Other configurations are shown in FIG.
It is similar to that shown in (a) and (b), and the same parts are denoted by the same reference numerals.

Also in this embodiment, the penetrating force of the secondary air 8 supplied from the secondary air supply nozzles 9 arranged on the left and right side walls 2d and 2e of the combustion chamber can be increased in the combustion chamber 2. The same effects as those shown in FIGS. 1A and 1B can be obtained.

In each of the embodiments shown in FIGS. 1 (a) (b) to 4, the left and right side walls 2d of the combustion chamber 2 are used.
2 and 2e, the air supply nozzles 9 for the secondary air 8 as the combustion air are arranged with staggered positions so as not to face each other in the left-right direction. Similar to the arrangement of the secondary air supply nozzle 9, an air supply nozzle 11 for the tertiary air 10 as combustion air.
By arranging the above, the tertiary air 1 formed by arranging the tertiary air supply nozzles 11 on the left and right side walls 2d and 2e of the combustion chamber 2 in a staggered manner so as not to face each other in the left-right direction.
An air supply device for 0 may be provided. In this case, the tertiary air 10 is supplied to the inside of the combustion chamber 2 from the tertiary air supply nozzles 11 arranged on the left and right side walls 2d and 2e of the combustion chamber 2. The tertiary air can be supplied in a state in which the penetrating force is increased without being made to face each other.
By 0, mixing and stirring in the combustion chamber 2 can be promoted, and RDF
It becomes possible to improve the combustion efficiency of the post combustion of 13 slags.

The present invention is not limited to the above embodiment, and the supply nozzles 9 for the secondary air 8 as combustion air provided on the left and right combustion chamber side walls 2d and 2e do not face each other. If the secondary air 8 is blown into the combustion chamber 2 so as not to face the left and right secondary air 8 supply nozzles 9 and mixed and agitated with the combustion gas, Each combustion chamber side wall 2d and 2e
The arrangement of the supply nozzle 9 for the secondary air 8 in FIG.
(A) (b) The arrangement in each of the embodiments shown in FIGS.
If the high-temperature combustion gas 14 generated by the combustion of F13 can be used as a heat source for steam generation, it can be applied to the RDF-fired stoker boiler I of the type in which the heat exchange section is provided at a position other than the upper side of the combustion chamber ceiling wall 2c. Alternatively, it may be applied to an RDF-fired stoker boiler I that employs a heat exchange unit other than the smoke tube group 12, or applied to a stoker boiler that burns waste fuel other than the RDF 13 as fuel. It goes without saying that various changes can be made without departing from the scope of the present invention.

[0027]

As described above, according to the present invention, the following excellent effects are exhibited. (1) The air supply method for the stoker-type boiler, in which the combustion air blown into the combustion chamber from both the left and right side walls of the combustion chamber of the stoker-type boiler is blown in a staggered manner so as not to be opposed to each other in the left-right direction, but alternately. , An air supply device for a stoker type boiler having air supply nozzles on the left and right side walls of the combustion chamber of the stoker type boiler, which are staggered so as not to face each other in the left-right direction. Therefore, the penetration force of the combustion air blown into the combustion chamber from the air supply nozzle can be increased, and the mixing and stirring in the combustion chamber can be promoted, so that the combustion state can be improved and carbon monoxide It is possible to suppress the generation of dioxins and the generation of dioxins. (2) Further, on the side walls of the left and right combustion chambers, rows of air supply nozzles arranged in the vertical direction are provided so as to be staggered in the front-rear direction, or a plurality of rows are arranged in the vertical direction and the front-rear direction. A set of air supply nozzles or one air supply nozzle may be arranged in a zigzag pattern so as to be staggered in the vertical direction and the front-back direction, or rows of air supply nozzles arranged in the front-back direction may be arranged in the vertical direction. By providing the staggered arrangements in the direction, the combustion air can be blown and supplied into the combustion chamber from the air supply nozzles provided on the left and right side walls of the combustion chamber without facing each other.

[Brief description of drawings]

FIG. 1 shows an RDF as an example of a stoker type boiler of the present invention.
1 shows an embodiment of an air supply method and apparatus applied to a stoker-type boiler, (a) is a schematic sectional side view,
(B) is a view of the arrow (A) taken in the AA direction.

FIG. 2 is a schematic sectional side view showing another embodiment of the present invention.

FIG. 3 is a schematic sectional side view showing still another embodiment of the present invention.

FIG. 4 is a schematic sectional side view showing still another embodiment of the present invention.

5A and 5B schematically show an example of an RDF-fired stoker-type boiler as a conventional stoker-type boiler, in which FIG. 5A is a sectional side view, and FIG. 5B is a view taken in the direction of arrow B-B in FIG.

[Explanation of symbols]

I RDF fired stoker boiler 2 combustion chamber 2a Combustion chamber front wall 2b Combustion chamber rear wall 2c Combustion chamber ceiling wall 2d, 2e combustion chamber side wall 8 Secondary air (combustion air) 9 Secondary air supply nozzle (air supply nozzle) 10 Tertiary air (combustion air) 11 Tertiary air supply nozzle (air supply nozzle) 13 RDF (fuel) 14 Combustion gas

Claims (6)

[Claims] 1. An air for a stoker-type boiler, characterized in that combustion air blown into the combustion chamber from the left and right side walls of the combustion chamber of the stoker-type boiler is blown in a staggered manner so as not to oppose each other in the left-right direction. Supply method. 2. The stoker-type boiler has a structure in which air supply nozzles are arranged on both left and right side walls of a combustion chamber in a staggered manner so as not to face each other in the left-right direction. Air supply device for stoker type boiler. 3. A plurality of air supply nozzles provided on the left and right side walls of the combustion chamber are arranged in a row in the vertical direction, and rows of the air supply nozzles on the left and right side walls of the combustion chamber are staggered in the front-rear direction. The air supply device for a stoker type boiler according to claim 2, wherein the air supply device is provided so as to have the above arrangement. 4. A set of a plurality of air supply nozzles provided on the left and right side walls of the combustion chamber, the set of air supply nozzles being arranged in a vertical direction and a plurality of air supply nozzles in the front-back direction. The air supply device for a stoker type boiler according to claim 2, wherein the air supply devices are arranged in a staggered manner so as to be staggered in the vertical direction and the front-back direction. 5. The air supply nozzles provided on the left and right side walls of the combustion chamber are arranged in a staggered arrangement, and the air supply nozzles are arranged on the left and right side walls of the combustion chamber in a staggered arrangement in the vertical direction and the front-back direction. Item 2. An air supply device for a stoker type boiler according to Item 2. 6. The air supply nozzles provided on the left and right side walls of the combustion chamber are rows of air supply nozzles arranged in the front-rear direction, and the rows of air supply nozzles on the left and right side walls of the combustion chamber are staggered in the vertical direction. The air supply device for a stoker type boiler according to claim 2, wherein the air supply device is provided so as to have the above arrangement.