JPH01118008A - Fluidized bed combustion device - Google Patents

Abstract

PURPOSE:To enable stable operation of a fluidized bed boiler even during partial load operation and to enable easy change of a stopping fluidized bed to an operating fluidized bed even during a change in a load, by a method wherein, during partial load operation, operation fluidized bed are formed on both sides of the stopping fluidized bed to perform the operation. CONSTITUTION:In a fluidized bed boiler 1, operating fluidized beds 13 are formed on both sides of a stopping fluidized bed 14, and the number of cells of the operating fluidized bed 13 are increased to perform operation. When the number of the cells of the operation fluidized bed 13 are increased, air for fluidization and air for combustion are fed to small air chambers 10b, 12a, and 12h to form operation fluidized beds 13 and 13 on the left end and the right end of each of upper and lower stage fluidized beds 4 and 5. As notes above, by forming the operation fluidized beds 13 and 13 on both sides of the stop fluidized bed 14, an amount of a flying fluidizing medium deposited on the stop fluidized bed is decreased, an amount of the fluidizing medium of the operating fluidized bed is increased, and blowby phenomenon can be prevented from occurring to the operation fluidized bed. This constitution enables easy change of the stopping fluidized bed to the operating fluidized bed even during partial load operation, and permits the stable operation of the fluidized bed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fluidized bed combustion apparatus using coal or pulverized coal in a ftmc fluidized bed, and more particularly to a fluidized bed boiler operated at partial load.

[Conventional technology]

In recent years, the demand for coal has been increasing due to the fuel conversion from petroleum fuel to coal fuel, but coal fuel has a higher content of 8% and 8% compared to petroleum fuel, so the amount of SOx and NOx generated is large, making pollution regulations difficult. Fluidized bed combustion is attracting attention as it allows cleaner combustion of coal fuel.

For example, in a fluidized bed boiler, coal and limestone of 1 to 10 mm are used as fluidized media in granular form, and 80 to 9
Since combustion can be performed at a relatively low temperature of 00C, the combustion temperature is lower than that of a fluidized bed boiler and a conventional pulverized coal-fired boiler, and desulfurization can be performed at the same time as combustion. It has the characteristics of reducing the amount of NOx generated.

The outline of the fluidized bed combustion apparatus will be described below using FIGS. 7 to 15, taking an IN, 1E1, single-layer boiler as an example.

The fluidized bed boiler 1 is equipped with air dispersions 2 and 3, and above the air dispersions 2 and 3, an upper fluidized bed 4 and a lower fluidized bed 5 are formed by solid particles such as coal 1 limestone and combustion ash. Heat exchanger tubes such as an evaporator 6 and a secondary superheater 7 and a secondary reheater 8 are arranged in the fluidized bed 4 and in the lower fluidized bed 5, respectively.

On the other hand, an upper wind box 10 and a lower wind box 12 are formed below the air distribution plates 2 and 3, and the upper wind box 10 is separated by a partition plate 9 into a small air chamber 10.
a-10f, the lower wind box 12 has partition plate 1
1 into small air chambers 12a to 12h.

In addition, 13 in the figure is an operating fluidized bed, 14 is a stopped fluidized bed, and 1
5 is a primary reheater, 16 is a primary superheater, 17 is an energy saver, 1
8 is a deposited layer of scattered muddy medium deposited on the stopped fluidized bed 14.

In such a structure, FIGS. 7, 10 and 13
As shown in the figure, a fluidized bed boiler 1 that uses limestone as a fluid medium and contains desulfurizing agent particles is equipped with an upper fluidized bed IW 4 and a lower fluidized bed 5. Then, upper and lower fluidized beds 4,
5 is supplied with coal from a crushed coal bunker (not shown), and the supplied coal is burned at 800 to 820C in the upper fluidized bed 4 or the lower fluidized bed 5, and the combustion energy is transferred to the a# layer 4. 5, heat exchange is carried out with the evaporator 6 of the upper fluidized bed 4, the secondary superheater 7 and the secondary reheater 8 of the lower fluidized bed 5 to efficiently absorb combustion energy and produce steam of the required quality. It causes it to occur.

In such a structure, fAIIC will be explained about the case where the conventional fluidized bed boiler is operated at partial load 11rt and the auxiliary layer 13 is increased.

8 and 9 show plan views of the small air chamber shown in FIG. 7, FIGS. 11 and 12 show plan views of the small air chamber shown in FIG. 10, and FIGS. The figure shows a plan view of the small air chambers in FIG. 13, and the hatched portions of the small air chambers 10a-1Of and small air chambers 12a to 12h indicate the small air chambers of the operating fluidized bed 13.

In FIG. 7, when the operating fluidized beds 13 of the upper fluidized bed 4 and the lower fluidized bed 5 are - cells, the operating fluid ith layer 13 is equipped with a starting hot blast furnace (not shown), The chambers 12C and 12d are started by hot air from a hot air stove as shown by diagonal lines in FIGS. 8 and 9, and after heating the fluidized medium in the operating fluidized bed 13, the coal is ignited.

Next, the operating fluidized bed 13 shown in FIG.
When increasing the number of operating fluidized beds 13 shown in the figure to double cells, the small air chamber 10 b adjacent to the small air chamber io a, and the small air chamber 12 b adjacent to the small air chambers 12 c, 12 d Kljli
.

12 e as shown by diagonal lines in FIGS. 11 and 12, fluidizing air is supplied to
By transferring heat to the operating fluidized bed 13 and operating the stopped flow 1m 14 to the operating fluidized bed 13 for Tkm, the operating fluidized bed 13
-increases from cell to cell.

In addition, the operating fluidized bed 13 shown in FIG.
When increasing the operating fluidized bed 13 shown in Fig. 3 to three cells, the small air chamber 10 b
c and the small air chambers 12b, 12e K-contacting small air chambers 12a.

The number of operating fluidized beds 13 was increased from two cells to three cells by supplying fluidizing air to the 12th cell and the 14th cell, as shown in the cellar of FIG. 15.

In this manner, in the conventional fluidized bed boiler l, fluidizing air is supplied one after another to the small air chambers adjacent to the operating fluidized bed 13, and the operating fluidized bed 13 is widened and the stopped fluidized bed is narrowed to reduce the fluidized bed. He was operating Boiler 1.

However, the small air chambers 10a to 10f of the upper wind box 10 shown in FIGS. 7, 10, and 13
.

When air for fluidization and combustion is supplied to all of the small air chambers 12a to 12h of the lower wind box 12, and the upper fluidized bed 4 and the lower fluidized bed 5 are all operated as the operating fluidized bed 13. There is no problem with this, but from Figure 7 to Figure 1
As shown in Figures 0 and 10 to 13, only some of the small air chambers IQa-10c of the upper wind box 10 and the small air chambers 12a to 12h of the lower wind box 12 are used for fluidization and combustion. The operating fluidized bed 13 is supplied with
When the stopped fluidized bed 14 and the stopped fluidized bed 14 coexist, that is, at partial load (
For example, 75%, 50%, 40% load) are problematic.

[Problem that the invention seeks to solve]

That is, when the conventional fluidized bed boiler 1 shown in FIGS. 7 to 15 is operated at partial load, the operating fluidized bed 13 and the stopped fluidized bed 1 are separated as shown in FIGS. 7, 10, and 13.
4, that is, in FIG. 7, the small air chamber 10
b, 12b, 12e, 10C in Figure 10
112a, 12f, small air chamber 1 in Fig. 13
0d, 12a.

12 g, the fluidized medium of the operating fluidized bed 13 is scattered onto the stopped fluidized bed 14, and finally a deposited layer 18 of the scattered fluidized media is formed on the stopped fluidized bed 14, and the gravity of this deposited layer 18 causes a small Air chambers 10b, 10c, 10d, 12a, 1
2b, 12e.

It becomes impossible to change the stopped flow #14 on 12f and 12g to the operating fluidized bed 13.

On the other hand, in the operating fluidized bed 13, since the amount of fluidized medium is drastically reduced, a phenomenon occurs in the blowing of air for fluidization and combustion in the operating fluidized bed 13, and eventually the operation of the operating fluidized bed 13 becomes impossible, and as a result, the fluidized bed 13 becomes unable to operate. There was a drawback that the operation of the entire bed boiler 1 was also impossible.

The present invention aims to eliminate such conventional drawbacks,
The purpose of this is to enable stable operation of a fluidized bed boiler even under partial load, and to easily change a stopped fluidized bed to an operating fluidized bed even when the load changes. The aim is to obtain a combustion equipment.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention operates by forming operating fluidized beds on both sides of a stopped fluidized bed during partial load.

[Effect]

Since the operating fluidized bed is formed on both sides of the stopped fluidized bed, the amount of scattered fluidized media deposited on the stopped fluidized bed is reduced, the amount of fluidized medium in the operating fluidized bed is increased, and the blowout in the operating flow m layer is reduced. The phenomenon can be prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 4 are cross-sectional views of a fluidized bed boiler according to an embodiment of the present invention, and are diagrams for explaining the increase in the number of operating fluidized beds, and FIGS.
5 and 6 are plan views of the wind box for explaining the air supply state in the wind box of FIGS. 1 and 4. FIG.

In FIGS. 1 to 6, numerals 1 to 18 indicate the same parts as the conventional ones.

The fluidized bed boiler 1 shown in FIGS. 1 and 4 is started up in the same manner as the conventional fluidized bed boiler 1 described in FIG. 7.

The difference between the conventional fluidized bed boiler and the #, dynamic J-boiler of the present invention is that the conventional fluidized bed boiler operates as shown in Figs. 7 to 10 and 10 to 13. When increasing the number of cells in the fluidized bed 13, the fluidized bed 13 was adjacent to the operating fluidized bed 13 and the next stopped fluidized bed 14 was heated, and the number of cells in the operating fluidized bed 13 was sequentially increased. In the bed boiler 1, operating fluidized beds 13 are formed on both sides of a stopped fluidized bed 14, and the number of cells in the operating fluidized bed 13 is increased for operation.

In other words, as shown in FIG. 7, the small air chambers 10a, 12c
.

When increasing the number of cells in the operating flow no. 13 from the operating state in which air for fluidization and combustion is supplied to 12d to the state shown in FIG. 1, first, the cells of the operating flow no. For fluidization into small air 110f, 12a, 12h,
Combustion air is supplied to form operating fluidized beds 13, 13 at the left and right ends of the upper fluidized bed 4 and lower fluidized bed wi5 in FIGS. 1, 2, and 3.

In this way, the operating fluidized bed 13.13 is placed on both sides of the stopped fluidized bed 140.
By forming the #IJJJ layer 14, as shown in FIG.
However, since the scattered fluidized medium collapses from both sides of the stopped fluidized bed 14 to the operating fluidized bed 13.131tlj,
The amount of scattered media in the deposited layer 18 is smaller than in the conventional case.

Moreover, the operating fluidized bed 13 changes from the state shown in FIG. 1 to the state shown in FIG.
When increasing the number of cells from two cells to three cells, fluidization and combustion air is supplied to the small air chambers 10d and 12f as shown by diagonal lines in FIGS. 5 and 6, and the stopped fluidized bed 14.14
A working fluidized bed 13.13 is formed on both sides.

In this way, the operating fluidized bed 13°1 is placed on both sides of the stopped fluidized bed 140.
3, the scattered ηLJ@ medium deposited on the stopped flow J@14 collapses into the continuous flow J 13.13, so the deposited layer 18 becomes smaller and the stopped fluidized bed 1
4 can be easily converted into a working fluidized bed 13.

In this way, the operation fluidized bed 130 and the thinning operation are stopped.
The scattered fluidized media collide with each other at the top, causing the piled f-18 to collapse toward the operating fluidized bed 13 and 13, so that a large mountain is not formed on the stopped fluidized bed 14, and the stopped fluidized bed 1
4 can control the temperature of the stopped fluidized bed 140 by heating from the operating fluidized beds 13 and 13 on both sides, so switching to the operating fluidized bed 13 becomes easy.

In the embodiments of the present invention, only the case where the number of cells in the operating fluidized bed 13 in the fluidized bed boiler 1 is increased has been described above, but when the number of cells in the stopped fluidized bed 14 is increased, it is the opposite of the previous explanation. If operated in this way, the load can be easily reduced.

〔Effect of the invention〕

According to the present invention, even during partial load, a stopped fluidized bed can be easily changed to an operating fluidized bed, and an operating fluidized bed can be easily changed to a stopped fluidized bed, and moreover, the fluidized bed can be operated stably.

[Brief explanation of the drawing]

1 to 6 relate to embodiments of the present invention, and the first
Figures 1 and 4 are cross-sectional views of the fluidized no-boiler, Figures 2, 3, 5, and 6 are plan views of the wind boxes in Figures 1 and 4, and Figures 7 to 15 are A conventional AM layer boiler is shown in FIG. 7, which is a plan view of an India box. 2.3...Air distribution plate, 4,5...Fluidized bed, 9゜11...Partition plate, 10.12...
...wind box, 10a, 10b, 1(
lc, 10d, IUe, 10f, 12a, 1
2b, 12c, 12d. 12e, 12f, 12g, 12h...-small air chamber, 13--operating fluidized bed, 14...-stopped fluidized bed. Figure 2 3 Figure 3 Figure 4 Figure 5 Figure 6 +2 (312n Figure 1θ Figure 11 Figure 12 +za +zn Figure 13 Figure 14 Figure 15 +2 (112rl

Claims (1)

[Claims] An air distribution plate is placed at the bottom of the fluidized bed to divide it into a fluidized bed and a wind box, and a partition plate is placed inside the wind box to divide it into small air chambers.At partial load, the fluidized bed is divided into an operating fluidized bed and a stopped fluidized bed. 2. A fluidized bed combustion apparatus which is operated separately in two parts, characterized in that during the partial load, operating fluidized beds are formed on both sides of the stopped fluidized bed.