JPH0244101A - Fluidized bed boiler - Google Patents

Abstract

PURPOSE:To enable active agitation and mixing of particles even when heat transfer pipe groups are densely situated in a fluidized bed by a method wherein density in a horizontal direction of the heat transfer pipes placed in the fluidized bed are brought into an uneven state in a horizontal direction. CONSTITUTION:Density in a horizontal direction of heat transfer pipes 7 is coarse in a part A and dense in a part B. Thus, heated air injected through an air nozzle 5 and raised in a fluidized bed 6 flows to the part A where pitch density is coarse, and this flow causes carriage of particles, with which the fluidized bed 6 is formed, to the upper part of a pipe group. Since an amount of gas flowing through the part B where density is high is decreased in this part, particles in the upper part of a pipe group are lowered in the part B under gravity. This constitution maintains enough agitation and mixing of particles, thereby the uniform agitation of particle and uniformization of a state in a bed, being the intrinsic features of the fluidized bed can be realized.

Description

[Detailed Description of the Invention] Industrial field 111] The present invention is directed to a fluidized combustion bed in which a thick pipe is arranged.
M for improving the floor 1°.

(Prior art) Figure 5 is a longitudinal sectional front view of an example of a conventional slag, moving bed boiler with heat exchanger tubes arranged in the J layer, Figure 6 is a front view of a new example, and Figure 6 is a front view of a new example. be.

In the sagittarius floor seki and ira, a lower υ-floor plate 2 of the furnace wall 1 is installed,
To this floor plate 201, particles of about several M of a mixture of coal as fuel and lime, sand, etc. as a combustion medium are poured into the floorboard 201 at any time from a fuel pipe (not shown) in a flowing medium. . Then, a wind chamber 3 is provided below the floor plate 2, and this wind chamber 3e
The hot air introduced from Wind'1li4 is 5. Air is ejected from a plurality of air nozzles 5 provided over the entire surface of the floorboard 2 into the fluidized medium on the floorboard 2. Then, this fluidized medium is stirred by the gas such as the hot air supplied from the furnace 1K and flows while burning, thereby forming a so-called fluidized combustion bed 6 (hereinafter referred to as a type ζ fluidized bed).

If the steam generated here is used for factory air supply or power generation (,
It's hot, as shown in the figure, heat transfer tubes 7 such as 'tM fluidic bed trend 6 tubes and caloheat tubes are installed. The heat exchanger tube 7 is connected to an inlet header 8 and an outlet header 9 arranged outside the furnace wall 1. For 1 case where the required heat absorption by heat transfer tube C is large,
In order to ensure the heat transfer capacity, conventionally 1. If the heat transfer tubes were arranged uniformly over the entire surface [the problem that the invention aims to solve], the above-mentioned conventional method? The A moving bed boiler had the following five problems to solve.

When the installation space of the boiler is limited, or when converting a heavy oil boiler to a lime-fired fluidized bed boiler, etc., if a large fluidized bed area is not possible, the furnace width W is narrow and the horizontal density of the heat transfer tubes 7 is This results in a narrow pitch.

If the heat transfer tubes are closely spaced at a narrow pitch, the movement of the fluidized medium will be restricted, and the agitation of particles in the fluidized bed will be suppressed. Therefore, the exchange of particles around the upper part of the heat transfer tube group and particles around the lower part becomes insufficient, causing non-uniformity in the conditions within the layer (temperature distribution, fuel distribution, etc.), leading to poor combustion and poor heat transfer. become.

An object of the present invention is to solve the above-mentioned problems and to maintain active stirring and mixing of particles even when a group of heat transfer tubes is densely provided in a fluidized bed.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a fluidized bed boiler having a group of heat exchanger tubes in the fluidized bed, characterized in that the horizontal density of the heat exchanger tubes arranged in the fluidized bed is non-uniform in the horizontal direction. This paper proposes a fluidized bed boiler.

[Function] Since the present invention is configured as described above, the gas rising in the fluidized bed flows more into the tube group with a coarse pitch density, thereby transporting the particles forming the fluidized bed to the upper part of the tube group. .

On the other hand, since the amount of gas flowing through the denser tube group decreases, the particles at the upper part of the tube group will descend in this tube group due to gravity.

Therefore, sufficient agitation and mixing of the particles is maintained, and uniform agitation of the particles and homogenization of the state within the bed, which are characteristics inherent in a fluidized bed, are achieved.

〔Example〕

FIG. 1 is a longitudinal sectional front view of an embodiment of the present invention, and FIG. 2 is a longitudinal sectional side view. In these figures, the same reference numerals are given to the same parts as those of the conventional device explained with reference to FIGS. 5 and 6, and detailed explanation thereof will be omitted.

In this embodiment, the horizontal density of the heat exchanger tubes 7 arranged in the fluidized bed 6 is non-uniform in the horizontal direction. That is, the horizontal density of the heat exchanger tubes 7 is coarse in part A of FIG. 1, and dense in part B.

Therefore, much of the hot air ejected from the air nozzle 5 and rising in the flow N6 flows into the section A where the pitch density is coarse, thereby transporting the particles forming the fluidized bed 6 to the upper part of the tube group. Since the amount of gas flowing in the dense part B is reduced, the particles at the upper part of the tube group will descend in this part B due to gravity. In this way, sufficient agitation and mixing of the particles is maintained, and uniform agitation of the particles and homogenization of the state within the bed, which are characteristics inherent in a fluidized bed, are achieved. In FIG. 1, arrows indicate the movement of fluidized particles.

FIG. 3 is a longitudinal sectional front view of another embodiment of the present invention, and FIG. 4 is a longitudinal sectional side view thereof. In these figures, the first
Components similar to those in the first embodiment described with reference to the figures and FIG.

In this embodiment, the heat exchanger tubes 7 are divided into three groups C, and gaps are provided between each group. Therefore, even in this embodiment in which the horizontal density of the heat transfer tubes 7 is coarse in the gap area and dense in the tube group C, the same effects as in the first embodiment can be achieved. .

〔Effect of the invention〕

In the present invention, circulating flow occurs at various locations within the fluidized bed,
Sufficient agitation of the fluidized media particles is maintained, making it possible to maintain fuel supply systems such as coal (overfeed or underfeed).
Regardless of the feeding method), the fuel in the bed is stirred without stagnation, and the original fluidized bed fuel is achieved.

The unit is therefore compact and costs are reduced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of one embodiment of the present invention, FIG. 2 is a longitudinal sectional side view, FIG. 3 is a longitudinal sectional front view of another embodiment of the invention, and FIG. 4 is a longitudinal sectional side view. Figure 5 is a longitudinal sectional front view of an example of a conventional fluidized bed boiler with heat exchanger tubes arranged in the fluidized bed.
FIG. 6 is a longitudinal side view as well. 1-Furnace wall 2-Floor plate 3...-Wind chamber 4--Air passage 5--Air nozzle 6--Fluidized bed 7--Heat transfer tube
8...Entrance header 9--Exit header agent Patent attorney Akigai Sakama 2 people Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] A fluidized bed boiler having a group of heat transfer tubes in the fluidized bed, characterized in that the horizontal density of the heat transfer tubes arranged in the fluidized bed is non-uniform in the horizontal direction.