JPH08312904A - Boiler - Google Patents

Abstract

PURPOSE: To contrive the simplification of structure, reduction of weight and the cut-down of cost, in a boiler prevented from a stress concentration at the vicinity of the lower end of a sub side wall in a connecting part between a furnace side wall and the side wall of the sub side wall. CONSTITUTION: A fluid take-out pipe 32 is connected to an intermediate header 13, permitting the supply of fluid, supplied through a lower furnace wall pipe 30, into upper furnace wall pipes 14 after collecting the fluid, while the fluid take-out pipe 32 is established upwardly from the lower part of the sub side wall bottom wall 9 of the sub side wall 2 whereby the side wall pipes 33 of the side of furnace side wall 6 in the side wall 8 of the sub side wall are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler.

[0002]

2. Description of the Related Art A general outline drawing of a heavy oil fired boiler is shown in FIG.
In FIG. 1, 1 is a furnace, 2 is a sub-side wall connected to the upper rear of the furnace 1, and 3 is a rear heat transfer section connected to the rear of the sub-side wall 2.

The furnace 1 is provided with a furnace front wall 4 and a furnace rear wall 5 as well as a furnace side wall 6 connecting both walls 4 and 5, and a burner 7 is arranged below the furnace front wall 4 and the furnace rear wall 5. ing.

The auxiliary side wall 2 is provided with left and right auxiliary side wall side walls 8 and an auxiliary side wall bottom wall 9 connecting the left and right auxiliary side wall side walls 8, and each auxiliary side wall side wall 8 is provided with respect to the corresponding furnace side wall 6. The auxiliary side wall bottom wall 9 is arranged side by side so as to be located in the same vertical plane, and is formed in an upward slope from the upper end of the furnace rear wall 5 toward the rear heat transfer section 3.

Reference numeral 10 is a damper arranged below the rear heat transfer section 3, 11 is an exhaust gas duct connected below the damper 10, and 12 is a combustion gas.

The fuel injected from the burner 7 is mixed with air and burned to generate a combustion gas 12, which is then burned.
Goes up in the furnace 1 and is introduced into the secondary side wall 2, is introduced from the secondary side wall 2 into the rear heat transfer section 3, descends from the rear heat transfer section 3, and is discharged from the damper 10 to the exhaust gas duct 11 as exhaust gas. To be done.

When the combustion gas 12 passes through the furnace 1, the side wall 2 and the rear heat transfer section 3, the furnace front wall 4, the furnace rear wall 5, the furnace side wall 6, the side wall side wall 8, and the side wall bottom wall 9 are formed. , Rear heat transfer part 3
Etc. and the fluid flowing through the heat transfer tubes housed in the upper part of the furnace 1, the sub side wall 2, and the rear heat transfer part 3 are heated.

In the above-mentioned boiler, a part of the water supplied to the front wall 4 of the furnace 1, the rear wall 5 of the furnace, and the side wall 6 of the furnace is withdrawn partway and introduced into the side wall 6 of the side wall 8 of the auxiliary side wall. However, if the entire amount is heated in a predetermined path to flow to the side wall 8 on the side wall side, the temperature of the fluid flowing on the side wall 8 on the side wall is higher than that of the fluid flowing on the front walls 4, 5, 6 of the furnace 1. Becomes

Therefore, when the temperature difference between the fluid flowing through the furnace side wall 6 and the fluid flowing through the sub side wall 8 is large, the furnace side wall 6 and the sub side wall 8 have a difference in elongation due to the temperature difference. In the vicinity X of the lower end of the connecting portion between the furnace side wall 6 and the side wall side wall 8 where the shape changes greatly, a large thermal stress may occur due to the difference in extension.

Therefore, conventionally, the above-mentioned vicinity X of the lower end of the connecting portion is used.
Measures are taken as shown in FIGS. 8, 9, and 10 so that a large thermal stress is not generated.

That is, as shown in FIGS.
The furnace side wall 6 is provided with a large number of furnace wall pipes 14 arranged vertically in parallel and fins 15 connecting adjacent furnace wall pipes 14 above the intermediate header 13 horizontally arranged in the boiler front-rear direction. Is formed in a panel shape as a whole, the lower end of the furnace wall tube 14 extends horizontally outward in the boiler width direction, and is connected to the intermediate header 13.

The furnace rear wall 5 is provided with a large number of furnace wall pipes 16 arranged vertically in parallel and fins 17 connecting adjacent furnace wall pipes 16 to each other, and is formed in a panel shape as a whole. Part of the furnace wall tube 16 extends upward from the upper end of the rear wall 5 of the furnace to the ceiling part so as to form the inlet part of the secondary side wall 2, and a part of the furnace wall tube 16 forms the secondary side wall bottom wall 9. Thus, at the upper end of the rear wall 5 of the furnace, it is bent upward toward the rear of the boiler and extends downwardly of the side wall 2 to form the bottom wall pipe 18 and the remaining furnace wall pipe 1
6 is a position slightly lower than the side wall bottom wall 9 and is bent horizontally toward the rear of the boiler to form a fluid take-out pipe 19. The tip of the pipe 6 is horizontally arranged below the side wall bottom wall 9 so as to extend in the boiler width direction. It is connected to the header 20.

A plurality of connecting pipes 21 are connected to the intermediate header 20, and the distal ends of the connecting pipes 21 are arranged below the intermediate header 20 on both sides in the boiler width direction. It is connected to 22.

A plurality of feed pipes 23 are connected to the intermediate header 22 at required intervals in the longitudinal direction of the intermediate header 22. The feed pipes 23 extend outward in the boiler width direction and upward. The side wall pipes 24 are bent toward each other and extend straight to the ceiling portion, and the side wall pipes 24 are formed in the sub side wall 2 portion on the upstream side in the combustion gas flow direction of the sub side wall 2. The adjacent side wall pipes 24 are connected by the fins 25. Is a part of the sub-sidewall 8 having a panel shape.

An intermediate header 26, which is substantially parallel to the intermediate header 22 and slightly above the intermediate header 22, is provided downstream of the side wall bottom wall 9 in the combustion gas flow direction.
The plurality of feed pipes 27 are connected to the intermediate header 26 at required intervals in the longitudinal direction of the intermediate header 26, and are arranged so as to be positioned on both sides in the boiler width direction. The side wall pipe 28 extends toward the ceiling portion, extends straight toward the ceiling, and forms a side wall pipe 28 on the side wall 2 downstream of the side wall 2 in the combustion gas flow direction. The fins 29 are connected to each other to form a part of the sub-sidewall side wall 8 in the form of a panel. The sidewall tubes 24 and 28 are also connected by fins.

Further, in FIG. 8, reference numeral 30 designates a furnace wall tube spirally wound around the outer periphery of the furnace 1 so as to form the lower part of the furnace 1, and the upper end side of the furnace wall tube 30 is an intermediate header 13. The adjacent furnace wall tubes 30 are connected to each other by fins 31.

In the boiler shown in FIGS. 8, 9 and 10, the fluid (water) that has risen in the furnace wall tube 30 of the furnace side wall 6 while being heated is introduced into the intermediate header 13, and the intermediate header 13 is introduced.
It is branched from and introduced into the furnace wall tube 14 and rises in the furnace wall tube 14 while being heated.

Similarly, the fluid rises in the furnace wall tube 16 of the rear wall 5 of the furnace, but part of it rises in the furnace wall tube 16 as it is, and part of it continues to the furnace wall tube 16 and the auxiliary side wall bottom wall 9 Fluid take-out pipe 1 that is introduced into the bottom wall pipe 18 of the
9 is introduced into the intermediate header 20.

Thus, the fluid introduced into the intermediate header 20 is introduced into the lower intermediate header 22 from the communication pipe 21, and the side wall pipe 24 of the auxiliary side wall 8 is passed from the intermediate header 22 through the feed pipe 23. It is introduced inside and rises while being heated.

The fluid heated to a high temperature while rising in the furnace wall tubes 14, 16 and the like in each of the furnace front walls 4, 5, 6 of the furnace 1 and the side wall pipe 24 in the sub side wall 8 of the sub side wall 2.
The fluid heated to a high temperature while rising in the inside and the fluid heated to a high temperature while flowing in the bottom wall pipe 18 in the sub-side wall bottom wall 9 of the sub-side wall 2 pass through a path (not shown). Is introduced into the intermediate header 26, branched from the intermediate header 26, introduced into the side wall pipe 28 in the sub side wall 8 and rises in the side wall pipe 28 while being heated.

In such a boiler, since the temperature of the fluid flowing in the furnace wall tube 14 and the temperature of the fluid flowing in the side wall tube 24 are substantially the same at the connecting portion of the furnace side wall 6 and the side wall side wall 8, the furnace side wall The difference in extension does not occur so much at the connecting portion between the side wall 6 and the side wall 8 of the auxiliary side wall, so that stress concentration due to thermal stress also occurs in the vicinity X (see FIG. 11) near the lower end of the connecting portion where the stress concentration easily occurs. Does not occur.

Further, in the above-mentioned boiler, due to the temperature difference of the fluid,
A large temperature difference occurs in the front-rear direction of the boiler at the boundary portion Y of the side wall pipes 24 and 28 in the sub side wall 8. Therefore,
A difference in extension occurs between the side wall 8 on the front side and the rear side of the boiler at the boundary portion Y, and thermal stress occurs, but before and after the boundary portion Y, the vicinity X of the lower end of the connecting portion between the furnace side wall 6 and the side wall sidewall 8 Since there is no large change in shape as described above, stress concentration does not occur, and therefore, there is no possibility that cracks or the like will occur in the side wall sidewall 8 at the boundary portion Y.

As described above, in the boiler shown in FIGS. 8, 9 and 10, the vicinity X of the lower end of the connecting portion between the furnace side wall 6 and the auxiliary side wall 8 is X.
Since no crack is generated in the boiler (see FIG. 11), the reliability of the boiler is improved.

[0024]

However, as shown in FIG.
In the boiler shown in FIGS. 9 and 10, the furnace side wall 6 and the auxiliary side wall 8
In order to prevent the expansion due to the temperature difference between the two at the connection part of the two, in order to feed the fluid from the part of the furnace wall pipe 16 in the furnace rear wall 5 to the side wall pipe 24, the intermediate headers 20, 22 and the connection are connected. Since the pipe 21 is required, the structure is complicated and the weight is increased.
This is a cause of cost increase.

In view of the above situation, the present invention uses a fluid having a relatively low temperature in the side wall of the furnace to prevent stress concentration near the lower end of the side wall of the side wall of the furnace and the side wall of the side wall. The purpose of the present invention is to eliminate the need for an intermediate header or a connecting pipe in order to be able to feed the material to the side, and to simplify the structure, reduce the weight, and reduce the cost.

[0026]

DISCLOSURE OF THE INVENTION The present invention provides a furnace in which generated combustion gas rises, and a side wall which is connected to the upper rear of the furnace to allow the combustion gas from the furnace to flow therethrough. , A rear heat transfer section for allowing combustion gas from the sub-side wall to descend, the side wall of the furnace being connected to an intermediate header, and being able to introduce fluid from below into the intermediate header. A plurality of furnace wall pipes, and a plurality of furnace wall pipes connected to the intermediate header and adapted to deliver the fluid upward, and the side wall of the sub-side wall allows the fluid to be delivered upward from below. In the boiler having a plurality of side wall pipes, the plurality of fluid take-out pipes are connected to the intermediate header, and the fluid take-out pipes are erected from below the sub-sidewall bottom wall so that the side wall of the sub-sidewall side wall on the furnace side wall side. It is a tube.

[0027]

Since the fluid introduced into the intermediate header is sent to the side wall pipe on the side wall of the furnace in the side wall of the auxiliary side wall through the fluid take-out pipe, a large difference in extension occurs at the connecting portion between the side wall of the furnace and the side wall of the auxiliary side wall. Therefore, stress concentration does not occur in both connection parts.

Further, since the fluid is fed from the intermediate header to the side wall pipe on the side wall of the furnace on the side wall of the auxiliary side wall through the fluid take-out pipe, another header or connecting pipe is unnecessary, and therefore the structure is simplified. In addition, the weight can be reduced and the cost can be reduced.

[0029]

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

In this embodiment, the furnace wall tube 16 of the rear wall 5 of the furnace extends from the lower part to the upper part to the ceiling part, and is bent to form the bottom wall tube 18 of the auxiliary side wall bottom wall 2. There are no groups that are suitable for the intermediate header 20 as shown in FIGS.

Further, the intermediate header 13 has a structure shown in FIGS.
As shown in FIG. 7, the front end of the furnace wall tube 30 and the lower end of the furnace wall tube 14 are connected (these configurations are the same as those of the conventional ones shown in FIGS. 8, 9 and 10), and a plurality of features which are the features of this embodiment are provided. Fluid take-out pipe 32 is connected.

The fluid take-out pipe 32 slightly projects horizontally to the left and right of the intermediate header 13 and is bent 90 degrees to extend upward.
When it extends slightly upward, it bends 90 degrees and extends horizontally behind the boiler, and it bends 90 degrees on the side of the auxiliary side wall 8 at the connecting portion between the furnace side wall 6 and the auxiliary side wall 8 and extends upward. Thus, the vertically extending fluid take-out pipes 32 are sequentially arranged below the auxiliary side wall bottom wall 9 from the side close to the furnace side wall 6 toward the rear of the boiler, and extend upward to the ceiling portion, whereby the auxiliary side wall 8 A side wall pipe 33 is formed in a portion close to the furnace side wall 6 in. The adjacent side wall pipes 33 are connected to each other by fins 34, and the side wall pipe 33 is the rearmost side wall pipe 33 of the side wall pipes 33 in the front-back direction of the boiler and the front-most side wall pipe 28 of the side wall pipes 28 in the front-back direction of the boiler. Are also connected by fins.

1 to 7, the same parts as those shown in FIGS. 8 to 11 are designated by the same reference numerals.

In the present embodiment, the fluid (water) which has been heated and has risen in the furnace wall tube 30 of the furnace side wall 6 is introduced into the intermediate header 13 and branched from the intermediate header 13 to branch into the furnace wall tube. It is introduced into the inside of the furnace wall tube 14, and rises in the furnace wall tube 14 while being heated. At this time, a part of the fluid in the intermediate header 13 is introduced from the intermediate header 13 to the fluid take-out pipe 32, flows through the fluid take-out pipe 32 into the side wall pipe 33 of the sub-side wall 8 and is heated while the side wall. Ascend in the pipe 33.

A part of the fluid that rises in the furnace wall tube 16 of the rear wall 5 of the furnace is introduced into the bottom wall tube 18 of the auxiliary side wall bottom wall 9, and the rest rises in the furnace wall tube 16 to the ceiling. To do.

The fluid heated to a high temperature while rising in the furnace wall tubes 14, 16 and the like in each of the furnace front walls 4, 5, 6 of the furnace 1 and the side wall pipe 33 in the sub side wall 8 of the sub side wall 2.
The fluid heated to a high temperature while rising in the inside and the fluid heated to a high temperature while flowing in the bottom wall pipe 18 in the sub-side wall bottom wall 9 of the sub-side wall 2 pass through a path (not shown). Is introduced into the intermediate header 26, branched from the intermediate header 26, introduced into the side wall pipe 28 in the sub side wall 8 and rises in the side wall pipe 28 while being heated.

Also in the boiler of this embodiment, as shown in FIGS.
As in the case of the boiler shown in FIG. 0, the temperature of the fluid flowing in the furnace wall pipe 14 and the side wall pipe 3 at the connecting portion between the furnace side wall 6 and the auxiliary side wall 8
Since the temperature of the fluid flowing in 3 is substantially the same, the difference in extension does not occur so much at the connection portion between the furnace side wall 6 and the auxiliary side wall 8 and, therefore, the lower end of the connection portion having the shape change portion where stress concentration is likely to occur. In the vicinity X, stress concentration due to thermal stress does not occur.

Further, in the boiler of the present embodiment, the side wall pipes 28 and 33 in the sub side wall 8 are accompanied by the temperature difference of the fluid.
A large temperature difference occurs in the front-back direction of the boiler at the boundary portion Y of.
Therefore, at the front and rear sides of the boiler at the boundary portion Y, the auxiliary side wall 8 is formed.
However, a thermal stress is generated, but before and after the boundary portion Y, the vicinity X of the lower end of the connecting portion between the furnace side wall 6 and the auxiliary side wall 8 is X.
Since there is no large shape change portion as described above, stress concentration does not occur, and therefore, there is no possibility that cracks or the like will occur in the sub-sidewall 8 at the boundary portion Y.

Further, in the boiler of this embodiment, the side wall pipe 3 in the sub side wall 8 is directly fed from the intermediate header 13 on the furnace 1 side.
3 is installed, the intermediate headers 20 and 2 that need to be installed in the case of the boilers in FIGS. 8 to 10.
2 and the connecting pipe 21 are not necessary, so that the structure can be simplified, the weight can be reduced, and the cost can be reduced.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0041]

According to the boiler of the present invention, it is possible to achieve various excellent effects such as simplification of the structure and reduction of the weight of the entire boiler, resulting in cost reduction.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of a boiler of the present invention.

FIG. 2 is a view taken along the line II-II in FIG.

FIG. 3 is a vertical cross-sectional view showing details of a connecting portion on a furnace side wall and a side wall side wall of the boiler of FIG.

FIG. 4 is a plan view showing a portion IV of FIG. 2 in an enlarged manner and accurately.

FIG. 5 is a view in the direction of arrows VV in FIG. 4;

6 is a VI-VI direction arrow view of FIG.

FIG. 7 is a view taken in the direction of arrow VII-VII in FIG.

FIG. 8 is a side view of an example of a conventional boiler.

9 is a view taken in the direction of arrow IX-IX in FIG.

FIG. 10 is a view taken in the direction of arrow XX in FIG.

FIG. 11 is a side view for explaining general matters of a boiler of the same type as the boiler shown in FIGS. 1 and 8.

[Explanation of symbols]

 1 Furnace 2 Secondary Sidewall 3 Rear Heat Transfer Section 6 Furnace Sidewall (Sidewall) 8 Secondary Sidewall Sidewall (Sidewall) 9 Secondary Sidewall Bottom Wall 13 Intermediate Header 14 Furnace Wall Tube 28 Sidewall Tube 30 Furnace Wall Tube 32 Fluid Extraction Tube 33 Sidewall Tube

Claims (1)

[Claims] 1. A furnace in which generated combustion gas is allowed to rise, a sub-side wall connected to an upper rear portion of the furnace so that combustion gas from the furnace flows, and a combustion gas from the sub-side wall. Is provided with a rear heat transfer section, the side wall of the furnace has an intermediate header, and a plurality of furnace wall tubes connected to the intermediate header and adapted to introduce a fluid into the intermediate header from below, A plurality of furnace wall tubes connected to the intermediate header and adapted to deliver fluid upward, and a side wall of the secondary side wall comprises a plurality of sidewall tubes adapted to deliver fluid from lower to upper. In the boiler, a plurality of fluid take-out pipes are connected to the intermediate header, and the fluid take-out pipes are erected from below the sub-sidewall bottom wall to form a side wall pipe on the furnace side wall side of the sub-sidewall side wall. Boiler.