JPH08566Y2 - boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a boiler.

[Prior Art] A conventional boiler will be described below with reference to FIGS. 3 to 6.

Reference numeral 1 in the drawing denotes a boiler suspended and supported from a boiler steel frame (not shown), and is composed of a furnace 2, an auxiliary side wall 3, and a rear heat transfer section 4.

 Reference numeral 5 is a ceiling wall of the boiler 1.

6 is a front wall of the furnace 2, 7 is a side wall of the furnace 2, and 8 is a rear wall of the furnace 2.

 Reference numeral 9 is a side wall of the sub side wall 3.

Reference numeral 10 is a front wall of the rear heat transfer section 4, and 11 is a side wall of the rear heat transfer section 4.

Further, the front wall 6, the side wall 7, the rear wall 8 and the side wall 9 of the auxiliary side wall 3 of the furnace 2 and the front wall 10 and the side wall 11 of the rear heat transfer section 4 connect the plurality of heat transfer tubes with fins. It is composed of.

In the upper part of the rear wall 8 of the furnace 2 among these furnace walls, the upper ends of the fins 13 are aligned at the same height to form a horizontal portion 14.

The heat transfer tubes 12 (bulk tubes) which are not connected by the fins 13 extending from the upper part of the rear wall 8 of the furnace 2 extend just above every other tube to suspend and support the rear wall 8 of the furnace 2 from a boiler steel frame (not shown). The remaining loose heat transfer tubes 12 are arranged, for example, in front of the hanger tubes 15 so as to be arranged in a line, and a screen for passing combustion gas generated in the furnace 2 to the side wall 3 is provided. It is said to be tube 16.

Further, the lower portion of the side wall 9 of the sub-side wall 3 has fins 20 for connecting the heat transfer tubes 19 (bulk tubes) rising from the headers 17 and 18.
The lower ends of the fins 20a, 20b on the furnace 2 side and the rear heat transfer section 4 side are extended to a position lower than the central portion, and an upwardly convex arched portion 21 is formed.

Furthermore, the end of the arch-shaped part 21 formed on the lower part of the side wall 9 of the auxiliary side wall 3 on the furnace 2 side and the end of the horizontal part 14 formed on the upper part of the rear wall 8 of the furnace 2 have the same height. Has been done.

Reference numeral 22 is an exhaust gas duct connected to the rear heat transfer section 4.

Combustion gas generated by the combustion of fuel in the furnace 2 of the boiler 1 flows in the order of the furnace 2, the side wall 3, and the rear heat transfer section 4, and the furnace wall of the furnace 2, the side wall 3, and the rear heat transfer section 4 is midway. After heating the steam and water flowing through the heat transfer tubes that are respectively configured, they are discharged from the exhaust gas duct 22 as exhaust gas.

In the boiler 1 in operation, since the temperature of the furnace 2, the auxiliary side wall 3, and the rear heat transfer part 4 are different from each other, the temperature between the furnace 2 and the auxiliary side wall 3 and between the auxiliary side wall 3 and the rear heat transfer part 4 is increased. An expansion difference due to the temperature difference occurs in each of the furnaces, and the expansion difference due to the temperature difference causes the furnace 2
Between the side wall 7 and the side wall 9 of the sub side wall 3 and the sub side wall 3
Thermal stress concentrates on the boundary portions between the side wall 9 of the rear heat transfer section 4 and the side wall 11 of the rear heat transfer section 4, respectively. By eliminating the sharp shape change portion, it is possible to prevent the thermal stress from concentrating on the boundary portions.

[Problems to be Solved by the Invention] However, the conventional boiler described above has the following problems.

That is, in the operating boiler 1, since the temperatures of the upper part and the lower part of the furnace 2 are different from each other, the rear wall 8 of the furnace 2 has a large upper part and a small lower part as shown by phantom lines in FIG. Although it will be deformed, a sharp shape change portion due to the horizontal portion 14 exists at the boundary portion between the upper portion of the rear wall 8 of the furnace 2 and the side wall 7, so that the thermal stress is concentrated on the boundary portion at the time of thermal deformation. Was there.

Further, the end of the arch-shaped portion 21 formed on the lower portion of the side wall 9 of the auxiliary side wall 3 orthogonal to the rear wall 8 of the furnace 2 on the furnace 2 side is just
Since the height is the same as the end of the horizontal portion 14 formed on the upper portion of the rear wall 8 of the furnace 2, the rigidity of the rear wall 8 of the furnace 2 sharply decreases at the upper horizontal portion 14, which causes thermal deformation. When the supporting load on each hanger tube 15 changes, the furnace 2
The stress caused by the change in the supporting load was generated in the upper portion of the rear wall 8.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a boiler capable of reducing various stresses generated in the upper portion of the rear wall of the furnace during thermal deformation.

[Means for Solving the Problems] In the present invention, an upwardly convex arch-shaped portion is formed at a lower portion of a side wall of a secondary side wall, and a downwardly convex arch-shaped portion is formed at an upper portion of a rear wall of a furnace orthogonal to the side wall of the secondary side wall. And the end of the arch-shaped part formed on the upper part of the rear wall of the furnace is higher than the end of the arch-shaped part formed on the lower part of the side wall of the sub-side wall on the furnace side. The present invention relates to a boiler, which is characterized in that a vertical overlapping portion is formed therebetween.

[Operation] According to the present invention, since the convex arch-shaped portion is formed on the upper portion of the rear wall of the furnace orthogonal to the side wall of the sub-side wall, a sharp shape change portion is formed at the boundary portion between the upper portion and the side wall of the rear wall of the furnace. Disappears,
The thermal stress concentrated in the boundary portion at the time of thermal deformation is dispersed.

Further, the end of the arch-shaped portion formed on the lower side wall of the auxiliary side wall orthogonal to the rear wall of the furnace on the furnace side is located higher than the end of the arch-shaped portion formed on the upper part of the rear wall of the furnace. Since the vertical overlap is formed between both ends in this way, the rigidity of the upper part of the rear wall of the furnace does not suddenly decrease, so when the supporting load applied to each hanger tube changes due to thermal deformation, The stress that has occurred in the upper part of the rear wall of the furnace due to changes in the supporting load is reduced.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

 1 and 2 show an embodiment of the present invention.

Further, in the figure, the same parts as those in FIGS. 3 to 6 are designated by the same reference numerals, and the description thereof will be omitted.

An arcuate portion 23 which is convex downward is formed on the upper portion of the rear wall 8 of the furnace 2 which is orthogonal to the side wall 9 of the auxiliary side wall 3.

The end 25 of the arched portion 23 formed on the upper portion of the rear wall 8 of the furnace 2 is positioned higher than the end 24 of the arched portion 21 formed on the lower portion of the side wall 9 of the auxiliary side wall 3 on the furnace 2 side. A vertical overlapping portion 26 is formed between both end portions 24, 25.

 Next, the operation will be described.

Since the convex arcuate portion 23 is formed downward on the upper portion of the rear wall 8 of the furnace 2 orthogonal to the side wall 9 of the auxiliary side wall 3, the rear wall 8 of the furnace 2 is formed.
There is no abrupt shape change portion at the boundary between the upper part of the and the side wall 9, and the thermal stress concentrated at the boundary at the time of thermal deformation is dispersed.

Further, the end portion 24 on the furnace 2 side of the arch-shaped portion 21 formed on the lower portion of the side wall 9 of the auxiliary side wall 3 orthogonal to the rear wall 8 of the furnace 2 is an arch-shaped portion formed on the upper portion of the rear wall 8 of the furnace 2. Since the vertical overlapping portion 26 is formed between both ends so as to be higher than the end portion 25 of 23, the rigidity of the upper part of the rear wall 8 of the furnace 2 does not suddenly decrease, so that thermal deformation does not occur. When the supporting load applied to each hanger tube 15 changes accordingly, the stress generated in the upper part of the rear wall 8 of the furnace 2 due to the change of the supporting load is reduced.

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

[Effects of the Invention] As described above, the boiler of the present invention has an excellent effect of reducing various stresses generated in the upper portion of the rear wall of the furnace during thermal deformation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall perspective view of an embodiment of the present invention, and FIG.
II-II arrow view of the figure, FIG. 3 is the whole perspective view of the conventional example,
FIG. 4 is a view on arrow IV-IV in FIG. 3, FIG. 5 is a view on arrow VV in FIG. 3, and FIG. 6 is a partially enlarged side view of FIG. In the figure, 2 is a furnace, 3 is a secondary side wall, 8 is a rear wall of the furnace 2, 9 is a side wall of the secondary side wall 3, 21 is an arch-shaped portion formed under the side wall 9 of the secondary side wall 3, and 23 is a rear side of the furnace 2. An arch-shaped portion formed on the upper portion of the wall 8, 24 is an end portion of the arch-shaped portion 21 on the furnace 2 side, 25 is an end portion of the arch-shaped portion 23, and 26 is an overlapping portion formed between both end portions 24 and 25. Show.

Claims (1)

[Scope of utility model registration request] 1. An arch-shaped portion which is convex upward is formed in the lower portion of the side wall of the sub-sidewall, and a arch-shaped portion which is convex downward is formed in the upper portion of the rear wall of the furnace which is orthogonal to the side wall of the sub-sidewall. Make sure that the end of the arch-shaped part formed on the upper part of the rear wall of the furnace is higher than the end of the arch-shaped part formed on the lower part of the side wall on the furnace side, so that there is a vertically overlapping part between both ends. Boiler characterized by being formed.