JPH11223303A - Sealing structure for heat transfer tube penetrating part through furnace wall of boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing structure for a heat transfer tube penetrating part through the furnace wall of a boiler, which can prevent the invasion of combustion ash into a ceiling chamber perfectly, and which is excellent in durability with a simple constitution. SOLUTION: Ferrite heat transfer tubes 22 are welded to a header 6 formed of ferrite steel, while an austenite heat transfer tube 23 is welded to the lower end of the ferrite heat transfer tubes 22. On the other hand, a heat transfer tube penetrating part 8 is opened on a furnace ceiling wall 3, formed of the ferrite steel, while a flat plate formed of the ferrite steel is welded to the circumference of the heat transfer tube penetrating part on the furnace ceiling wall 3. The austenite heat transfer tube 23 is penetrated through the heat transfer tube penetrating part, and the header is hung by a hanging bolt 10b. The upper end part of a seal box 13 formed of the ferrite steel is welded to the header 6 while the lower end of the seal box 13 is welded to the flat plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat transfer tube joined to a header placed outside a boiler furnace wall and penetrating through a heat transfer tube penetrating portion opened in the boiler furnace wall and arranged in the boiler furnace wall. The present invention relates to a seal structure of the heat transfer tube penetration portion in the boiler device.

[0002]

2. Description of the Related Art FIG. 14 shows a typical structure of a conventional large-sized boiler for power generation. In this type of large-sized boiler, a boiler furnace 4 includes a furnace side wall 2 and a furnace ceiling wall 3 manufactured by alternately welding a heat transfer tube and a fin bar, and is hung from a steel frame 1 by a suspension bolt 10a. . In a ceiling room 9 provided between the steel frame 1 and the furnace ceiling wall 3, a header 6 to which a heat transfer tube group 7 constituting a superheater or a reheater is connected, and a manifold 5 are suspended by suspension bolts 10b. The heat transfer tube group 7 is lowered, and the heat transfer tube group 7 penetrates through the heat transfer tube penetration portion 8 opened in the furnace ceiling wall 3.
Located in the superheater or reheater.

[0003] In the boiler furnace 4, the heat transfer tube group 7
Since it is heated by the combustion gas of not less than ° C., and the steam as the internal fluid also becomes high in temperature, the entire pipe extends downward due to thermal expansion. On the other hand, the suspension bolts 10a that suspend the furnace ceiling wall 3 from the steel frame 1 have a slight increase in temperature due to heat conduction from the furnace ceiling wall 3, but do not become as hot as the heat transfer tube group 7, so that the thermal expansion The amount of downward elongation due to is small. Therefore, the heat transfer tube group 7 in the heat transfer tube penetration portion 8
Of the relative elongation between the furnace and the furnace ceiling wall 3 is several tens mm
To 100 mm.

As shown in FIG. 15, the heat transfer tube penetrating portion 8 is usually constituted by omitting a part of the fin bar 11 for connecting the ceiling wall tube 12, and the periphery of the heat transfer tube penetrating portion 8, and By providing a clearance 17 between the penetrated heat transfer tube group 7 and the heat transfer tube group 7 and the furnace ceiling wall 3.
Is released to prevent the heat transfer tube group 7 from being subjected to excessive thermal stress.

In the case of a coal-fired boiler, which has become a mainstay of thermal power plants in recent years, if a clearance 17 is provided between the heat transfer tube penetrating portion and the heat transfer tube group 7, combustion ash enters the ceiling chamber 9. The problem arises. That is,
Usually, during boiler operation, the inside of the furnace 4 is controlled to have a negative pressure with respect to the ceiling chamber 9. However, in a transient operation state such as when the burner is ignited or extinguished, the inside of the furnace 4 is temporarily stopped. May become a positive pressure of 1 kg / cm ² or less, during which time the combustion ash in the furnace 4 enters the ceiling chamber 9 from the clearance 17 and accumulates. When the combustion ash enters and accumulates in the ceiling chamber 9 in this manner, inspection of piping such as the header 6 arranged in the ceiling chamber 9 is performed at the time of periodic inspection of the boiler device once every one to two years. Therefore, a large amount of burnt ash must be removed prior to the operation, which causes a disadvantage that the inspection requires a great deal of time and labor.

Conventionally, the following has been proposed as a means for preventing ash from entering the ceiling chamber 9.

[0007] As shown in FIG.
Is formed by welding one end of a seal box 101 formed in a shape capable of covering the ceiling tube 12 to the ceiling wall tube 12 and providing a sleeve 102 extending along the heat transfer tube group 7 on the other end side of the seal box 101.

As shown in FIG. 17, a refractory material 111 is provided on the furnace ceiling wall 3 so as to cover the heat transfer tube penetration portion 8, and a heat insulating material 112 is filled between the refractory material 111 and the heat transfer tube group 7. With bellows 113 (Japanese Unexamined Patent Publication No. 6-137)
506).

[0009] As shown in FIG. 18, a channel steel 121 seal-welded to the heat transfer tube group 7 around the heat transfer tube penetrating portion 8.
And a side plate 122 welded to the outer surface thereof, and a crown plate 123 welded at both ends to two side plates 122 disposed adjacent to each other.
Filled with a heat insulating material 124 in a space formed by a steel plate, a channel steel 121 and a side plate 122 (actually open flat 7-32).
309).

As shown in FIG. 19, a receiving plate 131 is arranged on the furnace ceiling wall 3, and the heat insulating material 1 is placed on the receiving plate 131.
32 and the refractory material 133, and the mounting frame 1 so as to surround the entire portion of the heat transfer tube group 7 protruding from the furnace ceiling wall 3.
34 provided with a skin casing 135 for a gas shield slidable with respect to 34 (JP-A-1-300102)
No. Gazette).

[0011]

However, of the above-mentioned known examples, the known example is required to prevent the deformation of the seal box 103 due to the expansion and contraction of the heat transfer tube group 7 and the fatigue failure. Since a certain amount of clearance 17 must be provided between the sleeve and the sleeve 102, combustion ash easily enters the ceiling room 9 from the clearance 17, and the combustion ash cannot be sufficiently prevented from entering the ceiling room 9. There are inconveniences.

[0012] In addition, among the above-mentioned known examples, the known examples 1 to 4 require a refractory material, a heat insulating material, and a heat insulating material as essential components, so that not only the structure is complicated and the cost is increased, but also Since it is necessary to replace the boiler once every one or two years at the time of regular inspection, there is a problem that it is not very effective in reducing the time and labor required for the inspection of piping.

Further, the heat transfer tube group 7 is generally made of austenitic steel having excellent heat resistance. However, since the austenitic steel is expensive, the bellows 11 in the known example is used.
3 and the flange 114 supporting it, the channel steel 121, the side plate 122, the crown plate 123 and the like in the known example are made of inexpensive ferrite steel. Therefore, in the above-described and known examples in which these dissimilar metals are joined by welding, cracks due to a difference in the coefficient of thermal expansion are easily generated from the welded portion, and there is a problem that the life of the boiler device is adversely affected.

In addition, in the known example, since the length direction of the header 6 and the length direction of the ceiling wall tube 12 forming the furnace ceiling wall are orthogonal to each other, the header 6 and the ceiling wall are arranged. Tube 1
2 to release the thermal expansion of the skin casing 135
Has to be slidably attached to the mounting frame 134, and therefore, there is a disadvantage that the mounting structure between the skin casing 135 and the mounting frame 134 is complicated. Also, the lower end of the skin casing 135 and the mounting frame 1
34 is slidably mounted, so that invasion of combustion ash into the ceiling chamber 9 cannot be completely prevented.

The present invention has been made in order to solve such deficiencies of the prior art, and an object of the present invention is to completely prevent combustion ash from entering the ceiling chamber 9 with a simple configuration. An object of the present invention is to provide a seal structure for a boiler furnace wall heat transfer tube penetration portion which can be prevented and has excellent durability.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a heat transfer tube joined to a header through a heat transfer tube penetrating portion opened in a boiler furnace wall and into a boiler furnace wall. In the boiler apparatus to be arranged, a length direction of the header and a length direction of a furnace wall tube constituting the boiler furnace wall are set in parallel, and formed in a shape capable of covering the periphery of the heat transfer tube penetration portion. One end of the sealed box is welded to the header, and the other end of the sealed box is directly welded to the boiler furnace wall around the heat transfer tube penetration, or to a strip-shaped flat plate welded to the boiler furnace wall. We adopted a configuration of welding.

For example, in the seal structure of the heat transfer tube penetration portion shown in FIG. 2, one end of the seal box 13 is welded to the header 6 and the other end is the furnace ceiling wall 3 around the heat transfer tube penetration portion 8 or the furnace ceiling. When welded to the flat plate 24 welded to the wall 3, the periphery of the heat transfer tube penetrating portion 8 can be completely sealed by the seal box 13, so that invasion of combustion ash into the ceiling chamber 9 can be completely prevented. However, it is possible to extremely easily check the piping arranged in the ceiling room 9.

The length direction of the header 6 and the furnace ceiling wall 3
Are arranged in parallel with the length direction of the ceiling wall tube 12, so that the seal box 13 is attached to the header 6 and the ceiling wall tube 12.
No thermal stress acts on the seal box 13 in the torsion direction even when both ends are welded. As described above, the heat transfer tube group 7 is generally made of austenitic steel having excellent heat resistance. However, the header 6 and the furnace ceiling wall 3 or the flat plate 24 are made of inexpensive ferritic steel for cost reduction. Therefore, if the seal box 13 is made of ferrite steel, welding between different metals can be avoided, and no large thermal stress acts on the welded portion. Therefore, it is possible to prevent the boiler life from being shortened due to the provision of the seal box 13.

Although the seal box 13 can be formed in a simple box shape, in order to further reduce the thermal stress acting on the seal box 13 and its welded portion, as shown in FIG. An expansion (easy deformation portion) 21 may be provided in a part.

The seal box 13 is fixedly welded to the header 6 and the furnace ceiling wall 3 or the flat plate 24 so as to enable inspection of piping arranged inside the seal box 13. It is preferable to comprise a part and a detachable part detachably attached to the fixed part. In this case, the attachment / detachment portion can be made detachable by screwing the attachment / detachment portion to the fixed portion, or can be made attachable / detachable by seal-welding the attachment / detachment portion to the fixed portion. In addition, when the expansion 21 is provided in the seal box 13, it is particularly preferable to use the expansion 21 as a detachable portion in order to simplify the apparatus.

One end and the other end of the seal box 13 can be directly welded to the header 6 and the furnace ceiling wall 3 or the flat plate 24. However, in order to facilitate removal and re-welding of the seal box 13, FIG. As shown in FIG. 5, welding ridges 16 are provided in advance on the header 6, the furnace ceiling wall 3, and the flat plate 24, and the sealing ridges 16 are provided on the welding ridges 16.
One end and the other end of 3 can also be welded.

As shown in FIG. 10, a high pressure air injection nozzle 31 is provided in the seal box 13 to return the combustion ash deposited in the seal box 13 to the boiler furnace 4 through the heat transfer tube penetrating portion 8. Can also be provided.

In addition, the seal box 13 can be formed in any shape as required. For example,
In addition to a simple square, as shown in FIG.
It is also possible to provide a tapered portion that becomes narrower toward the side.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A seal structure for a boiler furnace wall heat transfer tube penetration portion according to a first embodiment will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a schematic configuration diagram of a seal structure according to the present example, and FIG. 2 is a cross-sectional view illustrating a more specific configuration of the seal structure according to the present example.

As apparent from these figures, in the seal structure of the present embodiment, the heat transfer tube connected to the header 6 is composed of two portions 22 and 23 made of different materials, and the cross section is L.
The upper end of the seal box 13 formed in the shape of a letter is welded to the header 6, the lower end of the seal box 13 is welded to the flat plate 24 welded on the furnace ceiling wall 3, and opened on the furnace ceiling wall 3. The periphery of the heat transfer tube penetrating portion 8 is covered with a seal box 13. It should be noted that reference numeral 2 in FIG.
Reference numeral 5 denotes a hanging metal fitting for connecting the header 6 and the hanging bolt 10b.

The header 6 and the heat transfer tube 22 directly welded to the header 6 are formed of ferrite steel having excellent heat resistance, such as 1Cr-0.5Mo steel, and are welded to the lower end of the ferrite heat transfer tube 22. The heat transfer tube 23 is formed of austenitic steel having higher heat resistance. These heat transfer tubes 22 and 23 are joined via a dissimilar material welded portion 16. Further, the ceiling wall tube 12 and the fin bar 11 constituting the furnace ceiling wall 3 and the furnace ceiling wall 3
Is formed of a ferrite steel such as 1Cr-0.5Mo steel. On the other hand, since the seal box 13 is heated only up to about 300 ° C. and thus does not require oxidation resistance as high as that of the furnace ceiling wall 3 and avoids welding of dissimilar materials to the header 6 and the flat plate 24.
It is formed of a ferrite steel such as 5Mo steel or carbon steel.

The sealing structure of the boiler furnace wall heat transfer tube penetration portion of the present embodiment is such that a flat plate 24 is welded at one end of the seal box 13 to the header 6 and the other end is welded around the heat transfer tube penetration portion 8.
Therefore, the periphery of the heat transfer tube penetrating portion 8 can be completely sealed by the seal box 13, and the intrusion of the combustion ash into the ceiling chamber 9 can be completely prevented. Therefore,
Inspection of piping arranged in the ceiling room 9 can be made extremely easy.

The length direction of the header 6 and the furnace ceiling wall 3
Is made parallel to the length direction of the ceiling wall tube 12 and the header 6 and the furnace ceiling wall 3 are both formed of ferritic steel, so that the extension directions of the header 6 and the furnace ceiling wall 3 match. Further, since the difference in the amount of elongation is small, even if both ends of the seal box 13 are welded to the header 6 and the flat plate 24, a large thermal stress does not act in the length direction of the seal box 13. Further, since the header 6, the furnace ceiling wall 3, the flat plate 24, and the seal box 13 are formed of ferritic steel, welding between different metals can be avoided, and no large thermal stress acts on the welded portion. In addition, the suspension bolts 10b that suspend the header 6 and the suspension bolts 10a that suspend the furnace ceiling wall 3 are not directly heated and have almost the same temperature. Is small, and no large thermal stress acts on the seal box 13 in the vertical direction. Therefore, from these facts, it is possible to prevent the seal box 13 and the boiler device from being destroyed without providing the seal box 13 with any special means for releasing thermal stress.

In this embodiment, the seal box 1
3 was welded to a flat plate 24 welded to the upper surface of the furnace ceiling wall 3, but instead of such a configuration, a seal box 13 was used.
Can be directly welded to the ceiling wall tube 12 or the fin bar 11 constituting the furnace ceiling wall 3.

<Second Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to a second embodiment will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a seal structure according to the present example.

As is apparent from this figure, the seal structure of the present embodiment is characterized in that an expansion 21 for absorbing thermal stress acting in the vertical direction of the seal box 13 is provided in a part of the seal box 13. And The expansion 21 is bent in a W shape as shown in FIG. 3, and the upper side and the lower side are welded to the upper seal part 18 welded to the header 6 and the lower seal part 20 welded to the flat plate 24. ing. In this example, the expansion 21 is bent in a W-shape. However, it is needless to say that the expansion 21 can be formed in any shape as long as it can absorb the thermal stress acting in the vertical direction of the seal box 13.
Other features are the same as those of the seal structure according to the first embodiment, and a description thereof will be omitted to avoid duplication.

The seal structure of the boiler furnace wall heat transfer tube penetrating portion of this embodiment has the same effect as the seal structure according to the first embodiment, and furthermore, since the expansion box 21 is provided in a part of the seal box 13, the seal structure The box 13 can be expanded and contracted in the vertical direction, and the thermal stress acting on the seal box 13 and each weld can be further reduced. As described above, the relative displacement between the header 6 and the furnace ceiling wall 3 is slight, and the thermal stress acting on the seal box 13 does not usually cause a problem. It is suitable for a case in which the thermal expansion of the seal box itself is long and cannot be ignored.

<Third Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to a third embodiment will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a seal structure according to the present example.

As is clear from this figure, in the seal structure of this embodiment, the seal box 13 is composed of the upper seal part 18, the lower seal part 20, and the expansion 21, and the upper seal part 18 and the lower seal part 20 are formed. That the expansion 21 is detachably attached to the
And the lower seal component 20 is formed in a tapered shape that becomes narrower toward the furnace ceiling wall.

As shown in FIG. 4, the expansion 21 is bent in a substantially V-shape, and the upper and lower sides thereof are welded to the header 6 at the upper seal part 18 and the flat plate 24.
Is fastened to the lower seal part 20 welded by the mounting screw 26. In addition, in this example, the cross-sectional shape of the expansion 21 is formed in a substantially V shape, but any shape may be used as long as it can absorb the vertical thermal stress acting on the seal box 13. Of course, it is possible. On the other hand, the lower end of the lower seal part 20 is
It is welded to the innermost periphery of the flat plate 24. For others,
Since it is the same as the seal structure according to the second embodiment, the description is omitted to avoid duplication.

The seal structure of the boiler furnace wall heat transfer tube penetrating portion of this embodiment has the same effect as the seal structure according to the second embodiment, and an expansion 21 is detachably attached to a part of the seal box 13. Therefore, the mounting screws 26
The pipes enclosed by the seal box 13 can be inspected only by loosening the upper part and removing the expansion 21 from the upper seal part 18 and the lower seal part 20. Although the combustion ash has entered the seal box 13, if only the combustion ash in the limited space of the seal box 13 is removed, the piping can be inspected.
This can be greatly facilitated as compared with the case where the combustion ash invades the whole. Further, since the lower seal part 20 is formed in a tapered shape and the lower end thereof is welded to the innermost peripheral part of the flat plate 24, only the combustion ash accumulated in the seal box 13 is scraped off.
The scraped-off combustion ash can be efficiently returned into the boiler furnace 4 through the heat transfer tube penetrating portion 8, and the seal box 1
There is also an effect that cleaning of the inside 3 is easy.

<Fourth Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to a fourth embodiment will be described with reference to FIGS. 5 and 6. FIG. FIG. 5 is a cross-sectional view showing a seal structure according to the present example, and FIG. 6 is a side view thereof.

As is apparent from these figures, the seal structure of the present embodiment does not weld the seal box 13 directly to the header 6 and the flat plate 24, but to a weld for the welding that is previously welded to the header 6 and the flat plate 24. It is characterized in that it is welded to the ridges 27 and 27a, and that the seal box 13 is composed of two parts, an upper seal part 18 and a lower seal part 20, and these parts are joined by welding.

The welding ridges 27, 27a are formed of Mo steel or carbon steel. In case of new can boiler, header 6
And the flat plate 24 and the welding ridge 27a to the furnace ceiling wall 3,
Performed during production of the header 6 and the furnace ceiling wall 3 in the factory,
Heat treatment is performed after welding. Other features are the same as those of the seal structure according to the second embodiment, and a description thereof will be omitted to avoid duplication.

The seal structure of the boiler furnace wall heat transfer tube penetrating portion of this embodiment has the same effect as the seal structure according to the first embodiment, and the seal box 13 is welded to the header 6 and the flat plate 24 in advance. Since the welded ridges 27 and 27a were welded and the butted portions of the upper seal component 18 and the lower seal component 20 were joined by welding, the welded portion between the header 6 and the heat transfer tube 22 and the heat transfer tube during the periodic inspection. 22 and heat transfer tube 23
When it is necessary to check the welded portion between the seal box 13 and the welding ridges 27 and 27a, the butt welded portion between the upper seal component 18 and the lower seal component 20 is grinded with a grinder or the like. Since the whole or a part of the seal box 13 can be easily removed by shaving off, the inside of the seal box 13 can be easily inspected. At the time of restoration, the cut part is welded again and sealed. As described above, in the seal structure of the present example, the cutting and the re-welding are performed by the seal box 13 and the ridges 27 for welding.
27a and the butt weld of the upper seal part 18 and the lower seal part 20 are not damaged, so that the header 6 and the ceiling wall pipe 12, which are important high-temperature pressure-resistant members, are not damaged. Accidental leakage of internal fluid can also be prevented. Further, since the welding ridges 27 and 27a are formed of Mo steel or carbon steel, heat treatment after re-welding is unnecessary.

<Fifth Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to a fifth embodiment will be described with reference to FIG. FIG. 7 is a cross-sectional view showing a seal structure according to the present example.

As is apparent from this figure, the seal structure of the present embodiment is different from the seal structure of the boiler furnace wall heat transfer tube penetration portion according to the fourth embodiment shown in FIGS. Is characterized in that an expansion 21 is formed. Other features are the same as those of the seal structure according to the fourth embodiment, and a description thereof will be omitted to avoid duplication.

The seal structure of the boiler furnace wall heat transfer tube penetrating portion of the present embodiment has the same effect as the seal structure according to the fourth embodiment, and the lower seal part 2 of the seal box 13.
Since the expansion 21 is formed at 0, the seal box 13 can be expanded and contracted in the vertical direction, and the thermal stress acting on the seal box 13 and each weld can be further reduced.

<Sixth Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to a sixth embodiment will be described with reference to FIG. FIG. 8 is a cross-sectional view showing the seal structure according to the present example.

As is apparent from this figure, the seal structure of the present embodiment is different from the seal structure of the boiler furnace wall heat transfer tube penetration portion according to the fifth embodiment shown in FIG. Is not welded to the welding ridge 27a previously welded to the flat plate 24, but to the welding ridge 27a directly welded to the ceiling wall 12 constituting the furnace ceiling wall 3. . Other features are the same as those of the seal structure according to the fifth embodiment, and a description thereof will be omitted to avoid duplication.

The seal structure of the boiler furnace wall heat transfer tube penetrating portion of the present embodiment has the same effect as the seal structure according to the fifth embodiment.

<Seventh Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to a seventh embodiment will be described with reference to FIG. FIG. 9 is a side view showing the seal structure according to this example.

As is apparent from this figure, the seal structure of the present embodiment has a fixing portion 13a in which the seal box 13 is welded to welding ridges 27, 27a previously welded to the header 6 and the flat plate 24. Shielding plate 1 welded to fixing portion 13a
3b. Shield plate 13b
Is seal-welded to the periphery of the rectangular window hole 28 opened in the seal box 13. The other parts are the same as those of the seal structure according to the fourth embodiment, and the description thereof will be omitted to avoid duplication.

In the sealing structure of the boiler furnace wall heat transfer tube penetration portion of this example, the window hole 28 can be opened in a part of the seal box 13 by shaving off the welded portion of the shielding plate 29 with a grinder or the like. The inspection inside the seal box 13 can be easily performed, and the same effect as the seal structure according to the fourth embodiment can be obtained. At the time of restoration, the cut part is welded again and sealed.

<Eighth Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to an eighth embodiment will be described with reference to FIG. FIG. 10 is a cross-sectional view showing a seal structure according to this example.

As is apparent from this figure, the seal structure of the present embodiment is characterized in that an air injection nozzle 31 is provided on the upper seal part 18 of the seal box 13 which is welded to the header 6. The air injection nozzle 31 is attached vertically downward to the horizontal portion of the upper seal part 18, and is connected to the air pipe 32 connected to the air injection nozzle 31 for intermittently injecting high-pressure air from the air injection nozzle 31. An air valve 33 is provided. Other features are the same as those of the seal structure according to the third embodiment, so that the description will be omitted to avoid duplication.

The seal structure of the boiler furnace wall heat transfer tube penetration portion of this embodiment has the same effect as the seal structure according to the third embodiment shown in FIG. Since the nozzle 31 is mounted vertically downward, by injecting compressed air from the air injection nozzle 31 during periodic inspection of the boiler, the combustion ash deposited in the seal box 13 can be automatically and efficiently passed through the heat transfer tube penetration portion 8. It can be discharged, and inspection of piping provided in the seal box 13 can be further facilitated.

<Ninth Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to a ninth embodiment will be described with reference to FIG. FIG. 11 is a cross-sectional view showing a seal structure according to the present example.

As is clear from this figure, the seal structure of the present embodiment has two sets of air injection nozzles 3 on the upper seal part 18 and the lower seal part 20 of the seal box 13 respectively.
1a and an air injection nozzle 31b are provided. The air injection nozzle 31a attached to the upper seal component 18 is attached obliquely downward to the vertical portion of the upper seal component 18, and the air injection nozzle 31b attached to the lower seal component 20 is attached vertically downward. Other features are the same as those of the seal structure according to the eighth embodiment, and therefore, description thereof will be omitted to avoid duplication.

The seal structure of the boiler furnace wall heat transfer tube penetrating portion of this embodiment has the same effect as the seal structure according to the eighth embodiment shown in FIG. 2 for each side seal part 20
Since the set of the air injection nozzles 31a and 31b is provided, the air injection nozzle 31a attached to the upper seal component 18 is provided.
The combustion ash deposited in the seal box 13 is blown off, and the blown-out combustion ash can be discharged into the furnace 4 by the air injection nozzle 31 b attached to the lower seal part 20. Combustion ash can be discharged more efficiently. That is, since the air injection nozzle 31b is attached vertically downward to the tapered lower seal component 20, the air injection nozzle 31
When high-pressure air is injected from b, a high-speed air flow is generated in the heat transfer tube penetrating portion 8 and a strong suction force is generated. Therefore, the combustion ash in the seal box 13 can be discharged more efficiently than when the upper seal component 18 is provided with only the vertically downward air injection nozzle 31a.

<Tenth Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to a tenth embodiment is shown in FIG.
It will be described based on. FIG. 12 is a cross-sectional view showing the seal structure according to the present example.

As is apparent from this figure, the seal structure of the present embodiment is characterized in that the lower seal part 20 is not formed in a tapered shape but is vertically welded on the flat plate 24. Other features are the same as those of the seal structure according to the eighth embodiment shown in FIG. 10, and a description thereof will be omitted to avoid duplication.

In the seal structure of the boiler furnace wall heat transfer tube penetrating portion of the present embodiment, the lower seal component 20 is set vertically on the flat plate 24, so that the lower seal component 20 is tapered on the flat plate 24. Although the effect of discharging the combustion ash by the air injection nozzle 31 is slightly reduced as compared with the case, the structural strength of the seal box 13 can be increased because the lower seal part 20 is vertically welded to the flat plate 24, and the seismic resistance can be improved. Can be enhanced.

<Eleventh Embodiment> A seal structure of a boiler furnace wall heat transfer tube penetration portion according to an eleventh embodiment is shown in FIG.
It will be described based on. FIG. 13 is a cross-sectional view showing a seal structure according to this example.

As is apparent from this figure, in the seal structure of this embodiment, the end of the expansion 21 is not attached to the upper seal component 18 and the lower seal component 20 by screws 26 or the like, but is attached to the upper seal component 18 and the lower seal component 20. A seal welding 15a is provided at the ends of the upper seal part 18 and the lower seal part 20. Although the cross-sectional shape of the expansion 21 is U-shaped in FIG. 13, any shape may be used as long as it can absorb vertical thermal deformation acting on the seal box 13. . Other features are the same as those of the seal structure according to the eighth embodiment shown in FIG. 10, and a description thereof will be omitted to avoid duplication.

The seal structure of the boiler furnace wall heat transfer tube penetrating portion of the present embodiment has the same effect as the seal structure according to the eighth embodiment, and the expansion 21 and the upper seal component 18 and the lower seal component 20 are combined. Since the seal welding
The simplification of the configuration of each member and the assembly of each member,
Disassembly and reassembly can be facilitated. That is, when the expansion 21 and the upper seal component 18 and the lower seal component 20 are seal-welded, it is not necessary to form a screw hole or the like between the components, so that the configuration of each component can be simplified. In addition, according to the seal welding, each member can be easily joined as compared with screwing or the like, so that assembly of each member can be facilitated. At the time of disassembly, the expansion 21 is cut off with a grinder or the like so that the expansion 21 is connected to the upper seal part 18 and the lower seal part 20.
The inspection of the inside of the seal box 13 at the time of a periodic inspection or the like can be performed without any trouble, and the restoration can be easily performed by welding the cut portion again.

It should be noted that the gist of the present invention is not limited to those described in the above embodiments, but may be changed to other configurations by combining the configurations of the components described in the above embodiments. Of course, it is possible.

In each of the above embodiments, only the case where the heat transfer tube penetrating portion 8 is opened in the furnace ceiling wall 3 and the heat transfer tube group 7 penetrates has been described, but the gist of the present invention is not limited to this. Of course, the present invention can be applied to a case where a heat transfer tube penetration portion is opened at an arbitrary position on a boiler furnace wall.

[0064]

As described above, according to the present invention,
Since one end of the seal box was welded to the header and the other end was welded to the boiler furnace wall or the flat plate welded to the boiler furnace wall, the periphery of the heat transfer tube penetration portion could be completely sealed with the seal box. For example, it is possible to completely prevent combustion ash from entering a ceiling room or the like. Therefore, the inspection of the piping arranged in the ceiling room or the like can be made extremely easy.

Further, since the length direction of the header and the length direction of the furnace wall tube constituting the boiler furnace wall are parallel to each other, even if both ends of the seal box are welded to the header and the flat plate, the seal box remains in the seal box. Since a large thermal stress does not act, breakage of the seal box and the boiler device can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram schematically illustrating a seal structure of a heat transfer tube penetrating portion according to a first embodiment.

FIG. 2 is a cross-sectional view showing a seal structure of a heat transfer tube penetrating portion according to the first embodiment.

FIG. 3 is a cross-sectional view illustrating a seal structure of a heat transfer tube penetration portion according to a second embodiment.

FIG. 4 is a cross-sectional view showing a seal structure of a heat transfer tube penetrating portion according to a third embodiment.

FIG. 5 is a cross-sectional view showing a seal structure of a heat transfer tube penetration portion according to a fourth embodiment.

FIG. 6 is a side view showing a seal structure of a heat transfer tube penetration portion according to a fourth embodiment.

FIG. 7 is a cross-sectional view showing a seal structure of a heat transfer tube penetration portion according to a fifth embodiment.

FIG. 8 is a cross-sectional view illustrating a seal structure of a heat transfer tube penetrating portion according to a sixth embodiment.

FIG. 9 is a cross-sectional view illustrating a seal structure of a heat transfer tube penetrating portion according to a seventh embodiment.

FIG. 10 is a sectional view showing a seal structure of a heat transfer tube penetrating portion according to an eighth embodiment.

FIG. 11 is a cross-sectional view showing a seal structure of a heat transfer tube penetrating portion according to a ninth embodiment.

FIG. 12 is a sectional view showing a seal structure of a heat transfer tube penetration portion according to a tenth embodiment.

FIG. 13 is a sectional view showing a seal structure of a heat transfer tube penetrating portion according to an eleventh embodiment.

FIG. 14 is a schematic configuration diagram of a boiler device.

FIG. 15 is a sectional view of a heat transfer tube penetrating portion.

FIG. 16 is a sectional view showing a seal structure of a heat transfer tube penetration portion according to a first conventional example.

FIG. 17 is a cross-sectional view showing a seal structure of a heat transfer tube penetration portion according to a second conventional example.

FIG. 18 is a sectional view showing a seal structure of a heat transfer tube penetration portion according to a third conventional example.

FIG. 19 is a cross-sectional view showing a seal structure of a heat transfer tube penetration portion according to a fourth conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel frame 2 Furnace side wall 3 Furnace ceiling wall 4 Furnace 5 Manifold 6 Header 7 Heat transfer tube group 8 Heat transfer tube penetration part 9 Ceiling room 10a, 10b Hanging bolt 11 Fin bar 12 Ceiling wall tube 13 Seal box 16 Dissimilar material welding part 17 Clearance 18 Upper side Seal part 20 Lower seal part 21 Expansion 22 Ferrite heat transfer tube 23 Austenitic heat transfer tube 24 Flat plate 25 Hanging bracket 26 Screw 31, 31a, 31b Air injection nozzle 32 Air pipe 33 Air valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Koji Tamura, Inventor Koji, 3-36, Kure-shi, Hiroshima Babcock-Hitachi Inside Kure Research Laboratory (72) Inventor Yasuyoshi Sato 3-36, Takara-cho, Kure-shi, Hiroshima Babcock-Hitachi, Ltd. Kure Research Institute (72) Inventor Kazutaka Suzaki 3-36 Takaracho, Kure City, Hiroshima Prefecture Babcock Hitachi Kure Research Institute

Claims (8)

[Claims] 1. A boiler apparatus in which a heat transfer tube joined to a header is disposed in a boiler furnace wall through a heat transfer tube penetrating portion opened in a boiler furnace wall, wherein a length direction of the header and the boiler are arranged. The length direction of the furnace wall tube constituting the furnace wall is set to be parallel, and one end of a seal box formed in a shape capable of covering the periphery of the heat transfer tube penetrating portion is welded to the header, and the seal is formed. The other end of the box is directly welded to a boiler furnace wall around the heat transfer tube penetration portion, or is welded to a band-shaped flat plate welded to the boiler furnace wall, and a seal for the boiler furnace wall heat transfer tube penetration portion is provided. Construction. 2. The boiler furnace wall heat transfer tube penetration part according to claim 1, wherein the seal box is provided with an expansion for absorbing thermal stress in the seal box. Seal structure. 3. The sealing structure for a boiler furnace wall heat transfer tube penetration portion according to claim 1, wherein the seal box is fixed to the header and the fixed portion welded to the boiler furnace wall or a flat plate, and to the fixed portion. A seal structure for a boiler furnace wall heat transfer tube penetrating portion, comprising: a detachable portion detachably attached to the boiler furnace wall. 4. The seal for a through-hole of a boiler furnace wall heat transfer tube according to claim 3, wherein the detachable portion is screwed to the fixing portion. Construction. 5. The seal for a penetration portion of a boiler furnace wall heat transfer tube according to claim 3, wherein the detachable portion is seal-welded to the fixed portion. Construction. 6. The seal structure for a boiler furnace wall heat transfer tube penetrating portion according to claim 1, wherein one end of the seal box and another welding ridge provided on the boiler furnace wall or a flat plate. A seal structure for a boiler furnace wall heat-transfer tube penetration portion, the end of which is welded. 7. The sealing structure for a boiler furnace wall heat transfer tube penetrating part according to claim 1, wherein the dust collected in the seal box is returned to the boiler furnace through the heat transfer tube penetrating part in the seal box. A seal structure for a boiler furnace wall heat transfer tube penetrating portion, wherein an air injection nozzle is provided. 8. The seal structure for a boiler furnace wall heat transfer tube penetration portion according to claim 1, wherein a tapered portion which becomes narrower toward the boiler furnace wall side of the seal box is provided on the boiler furnace wall side of the seal box. A seal structure for a boiler furnace wall heat transfer tube penetrating portion, which is provided.