JPH08189601A - Furnace wall for fluidized bed boiler - Google Patents

Abstract

PURPOSE: To provide a furnace wall of a fluidized bed boiler which achieves a preventing of an evaporation pipe from wearing at a corner part at an upper part of a wear resisting refractory on which a fluid material or the like drops concentratedly. CONSTITUTION: At a lower part of a fluidized bed boiler, a furnace wall is made up of an evaporation pipe 1 lined with a wear resisting refractory 3. The evaporation pipe 1 at a corner above the part where the wear resisting refractory 3 is applied is bent inward and the furnace is built with corners thereof removed in a transverse configuration to eliminate a step between the pipe and the refractory 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a furnace wall of a fluidized bed boiler configured so that the fluidized material of the fluidized bed boiler does not concentrate on the corner portion of the furnace wall.

[0002]

2. Description of the Related Art A furnace wall structure of a fluidized bed boiler is shown in FIGS. In the conventional fluidized bed boiler, the evaporation pipes are arranged at right angles at the corners as in the case of heavy oil, crude oil, gas, and coal-fired boilers. In a fluidized bed boiler, silica sand is used as a fluid material and limestone is used as a denitration material to burn while jetting it with a fuel (such as coal), but the fluid material also scatters together with the combustion gas.

When these fluid materials reach the upper part of the combustor (combustion chamber), the buoyancy is reduced and they fall to the lower part of the combustor. In this case, the falling fluid material concentrates at the corners of the furnace wall, causing severe wear. That is, in the fluidized bed boiler, the lower part of the combustion chamber (combustor) is lined with wear-resistant refractory material, but the fluidized material concentrated at this end corner portion evaporates at a few corners as shown in FIG. The pipe was severely worn and a blast accident occurred in a short time.

[0004]

In the conventional fluidized bed boiler, the floating fluidized material blown at the corners of each wall (front wall and left and right walls, rear wall and left and right wall corners) concentrates and falls in the corners. Wear is concentrated on a few evaporation tubes. Therefore, that part is covered with a metal protector or the like, and the protector is renewed at every regular inspection.

At the place where the protector is mounted, it is necessary to carry out inspection and replacement by footing from the bottom of the furnace in the middle part of the combustor. Scaffold installation, protector inspection and replacement, periodic inspection for scaffold removal The number of days and the cost of each regular inspection increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a furnace wall of a fluidized bed boiler having a structure capable of preventing the evaporation pipe from being worn at the upper corner portion of the wear-resistant refractory material on which the fluid material and the like fall down. I am trying.

[0007]

In order to solve the above-mentioned problems in a fluidized bed boiler in which a furnace wall is constituted by an evaporation pipe whose lower portion is lined with wear-resistant refractory material, the wear-resistant fireproof material is applied. Provided is a furnace wall of a fluidized bed boiler having a configuration in which the evaporation pipe at the corner above the above-mentioned portion is bent inward and the cross-sectional shape of the furnace is made into a square-cornered shape to eliminate the step with the wear-resistant refractory material.

[0008]

In order to prevent the corners of the fluidized bed boiler from being severely worn by the fluid, the furnace wall according to the present invention has two to three corners of the evaporation pipe above the portion where the refractory material is applied, as described above. The step (unevenness) was eliminated at the end point of the wear resistant refractory material that was bent inward and installed in the middle part of the combustor.

Therefore, even if the fluid material concentrates on the corners and flows, the fluid material falls vertically along the evaporation tube. As a result, the abrasion of the evaporation pipe, which has occurred at the corner portion of the end point of the wear resistant refractory material lining, is prevented.

[0010]

EXAMPLE A furnace wall of a fluidized bed boiler according to the present invention will be specifically described below based on an example shown in FIGS. As shown in FIGS. 1 to 4, the combustor 2 of the fluidized bed boiler of the present embodiment is formed by connecting the evaporation pipes 1 continuously with fins or the like and surrounding them in a rectangle. A superheater 5, a reheater 6 and a economizer 7 are provided in the upper part of this,
It exchanges heat with the generated hot gas.

Further, on the inner circumference of the lower portion of the combustor 2, wear-resistant fireproof material 3 is provided via anchors 4 attached to fins or the like.
The corners of the evaporation tube 1 are formed at right angles as shown in FIG. The corner portion on the upper side of the wear resistant refractory material 3 has a corner drop shape as shown in the cross section of FIG. 3, and the evaporation pipe 8 at the corner is bent inward and the evaporation pipe 9 at the corner also Bent inward as well.

In the present embodiment, the three evaporation tubes at the corners are bent inward, but the number other than three may be used. Also,
The wear-resistant refractory material 3 in the lower part reaches half of the evaporation pipes 8 and 9 and the fin position, and the fluid material falling from the upper part falls vertically downward.

In the fluidized bed boiler, the fluid material is sandy, and if the fluid material concentrates and flows in one place, if there is unevenness, the fluid material lifted up along the convexity will now follow the recess. Flow and concave parts are subject to intensive wear.

At the corners of the furnace wall, the fluid material concentrates from the left and right walls, and more than twice as much fluid material falls as compared to the other portions. Therefore, the wear of the portion where the fluid material falls is 2
It was more than doubled and a blast accident occurred in a relatively short time.

In the furnace wall of this embodiment, as shown in FIG. 4, at the corners, the evaporation pipe is bent inward from the portion where the wear resistant refractory material is applied, and the refractory material (wear resistant refractory material lining) is formed.
By making the surface of 3 and the tube surface of the evaporation tube 1 vertical, there is no stepped portion on the inner surface of the corner furnace wall so that the fluid material does not drop into the evaporation tube, and the evaporation tube is not worn There is.

As described above, in the furnace wall of the fluidized bed boiler according to the present embodiment, since there is no step portion where the falling fluid material hits the upper corner portion of the wear-resistant refractory material where the fluid material concentrates and falls, The falling fluid material prevents the evaporation tube from being worn.

[0017]

As described above, in the furnace wall of the fluidized bed boiler according to the present invention, unevenness is formed in the corner portion above the portion where the refractory material, which is the place where the fluid material concentrates and falls, is applied. The evaporation tube is bent inward to eliminate it, and both the tube surface and the surface of the refractory material are made vertical to prevent the evaporation tube from being worn due to the entrainment of the fluid material. Therefore, unlike the conventional case, it is possible to provide a furnace wall of a fluidized bed boiler that does not require installation or replacement of a metal protector and is easy to maintain.

The fluidized bed boiler can burn a large amount of water such as coal, industrial waste, and garbage burning boiler by jetting a relatively large amount of soot and dust together with the fluid material, and a combustion temperature of 1000 ° C. or lower at a relatively low temperature. Since it can be burned at room temperature, the amount of NO _x and SO _x generated is small, and it has been installed in many industrial private power generation plants recently, and is considered to become the mainstream of future private power generation plants.

However, there is a drawback that wear occurs due to the fluid material, and emphasis is placed on measures against such wear, but the present invention can greatly contribute to one of these measures.

[Brief description of drawings]

FIG. 1 is an assembly view of a fluidized bed boiler according to an embodiment of the present invention.

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

FIG. 3 is a sectional view taken along line bb of FIG.

4A and 4B are enlarged detail views of an A portion of FIG. 3, in which FIG. 4A is a sectional view, FIG. 4B is a front view, and FIG.

FIG. 5 is an overall assembly view showing a conventional fluidized bed boiler.

6 is a cross-sectional view taken along the line cc of FIG.

FIG. 7 is an enlarged view of part B of FIGS. 5 and 6 (a).
Is a side view and (b) is a cross-sectional view.

[Explanation of symbols]

 1 Evaporation pipe 2 Combustor 3 Abrasion resistant refractory material 4 Anchor 5 Superheater 6 Reheater 7 Economizer 8 Evaporation pipe at corner 9 Evaporation pipe at corner 9

Claims (1)

[Claims] 1. A fluidized bed boiler in which a furnace wall is composed of an evaporation pipe whose lower portion is lined with wear-resistant refractory material, and in which the evaporation pipe at a corner above the portion where the wear-resistant fire resistant material is applied is located inside. A furnace wall of a fluidized bed boiler, wherein the furnace cross-section is bent into a square shape, and the cross-sectional shape of the furnace is made into a corner drop shape to eliminate the step with the wear resistant refractory material.