JPH0443685Y2

JPH0443685Y2 -

Info

Publication number: JPH0443685Y2
Application number: JP7158587U
Authority: JP
Priority date: 1987-05-15
Filing date: 1987-05-15
Publication date: 1992-10-15
Also published as: JPS63184303U

Description

【考案の詳細な説明】〔産業上の利用分野〕本考案は、ボイラの火炉壁と後部煙道壁の境界
下端近傍の炉壁に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a furnace wall near the lower end of the boundary between the furnace wall and the rear flue wall of a boiler.

[Conventional technology]

第２図はボイラ炉壁を概念的に示した側面図で
ある。火炉壁１に続く後部煙道壁のウエルデツド
ウオール２を構成する管は、管寄せ４に植え込ま
れる都合上、炉壁の端部でベア・チユーブ３にな
り、フイン端５が形成される。 FIG. 2 is a side view conceptually showing the boiler furnace wall. The tubes constituting the welded wall 2 of the rear flue wall following the furnace wall 1 become bare tubes 3 at the ends of the furnace wall, and fin ends 5 are formed in order to be implanted in the headers 4. Ru.

第３図は従来の火炉側壁と後部煙道側壁境界下
端近傍を示す。フイン１２はその終端５におい
て、端部を円形にカツトされ、その余肉は管１１
の表面に向つてなだらかにそぎ落してある。従来
は第３図のように、フイン端５を一直線上に配置
していたため、チユーブピツチに制限されて、フ
イン端５におけるフイン底のアールは小さくなら
ざるを得なかつた。 FIG. 3 shows the vicinity of the lower end of the boundary between the conventional furnace side wall and the rear flue side wall. The fin 12 is cut into a circular shape at its terminal end 5, and the excess material is used as the tube 11.
It is gently shaved down towards the surface. Conventionally, as shown in FIG. 3, since the fin ends 5 were arranged in a straight line, the radius of the fin bottom at the fin ends 5 had to be small due to the restriction of the tube pitch.

[Problem that the invention attempts to solve]

ボイラ起動時には第２図に示す火炉壁１と後部
煙道壁のウエルデツドウオール２との間に大きな
温度差が生じ、その伸び差を吸収するため、後部
煙道壁が火炉壁側へ喰い込むような変形が起こ
る。このため両壁境界下端近傍には力の流れが集
中し、フイン底アールが小さいことも相まつて高
い熱応力が生じるという問題点があつた。 When the boiler is started, a large temperature difference occurs between the furnace wall 1 and the welded wall 2 of the rear flue wall shown in Figure 2, and in order to absorb this difference in expansion, the rear flue wall moves toward the furnace wall. Severe deformation occurs. For this reason, the flow of force concentrates near the lower end of the boundary between both walls, and the small radius of the fin bottom also causes a problem of high thermal stress.

[Means for solving problems]

本考案は、上記問題点に鑑み、後部煙道壁を構
成する管のうち、応力の高いボイラ火炉壁とこれ
に続く後部煙道壁との境界下端近傍の後部煙道側
の管に、それぞれ高さを順次変えた管曲げ部を設
けることにより管ピツチの広い部分を形成し、フ
イン終端をこの位置に位置させることにより、フ
イン終端部におけるアールを大きくとれるように
した。 In view of the above-mentioned problems, the present invention has been developed to provide the following solutions to the tubes on the rear flue side near the lower end of the boundary between the highly stressed boiler furnace wall and the following rear flue wall, among the tubes that make up the rear flue wall. By providing pipe bending parts whose heights are successively changed, a wide part of the pipe pitch is formed, and by positioning the fin end at this position, a large radius can be obtained at the fin end.

[Effect]

本考案においては、上記のようにフイン終端部
における管のピツチを広くすることによつて、フ
イン底アールを大きくすることができ、このため
に応力集中係数が小さくなるため、フイン終端部
に発生する応力を低く押えることができる。 In the present invention, by widening the pitch of the tube at the end of the fin as described above, the bottom radius of the fin can be increased, which reduces the stress concentration factor, which generates stress at the end of the fin. It is possible to keep the stress low.

〔Example〕

第１図は本考案の一実施例における炉壁の構成
を表わす側面図である。後部煙道壁管１１は、火
炉壁管２１に近い方が最も下方に管曲げ部１６を
有し、それより後の管に行くに従つて、次第に高
さを高くしたところで順次管曲げ部１６が設けら
れている。従つて両端面が後部煙道管１１に取付
けられたフイン１２には部分的に広巾部１４が形
成される。また、本実施例では、フイン１２の終
端をこの広巾部に位置させている。以上の通り、
フイン１２の終端部は、管ピツチの広巾部１４に
位置しているので、この部分におけるフイン底１
５のアールを大きくとってフイン端を形成するこ
とが可能である。従つて、本実施例においては、
ボイラ起動時に力の流れが集中する火炉壁と後部
煙道壁との境界下面近傍のフイン終端部に発生す
る応力を低く押えることが可能である。 FIG. 1 is a side view showing the configuration of a furnace wall in an embodiment of the present invention. The rear flue wall tube 11 has a tube bending section 16 at the lowest position near the furnace wall tube 21, and the tube bending section 16 is sequentially formed at gradually higher heights toward the later tubes. is provided. Therefore, a wide portion 14 is partially formed in the fin 12 whose both end faces are attached to the rear flue pipe 11. Further, in this embodiment, the terminal end of the fin 12 is located in this wide portion. As above,
Since the terminal end of the fin 12 is located in the wide part 14 of the pipe pitch, the fin bottom 1 in this part
It is possible to form a fin end by increasing the radius of 5. Therefore, in this example,
It is possible to suppress the stress generated at the end of the fin near the lower surface of the boundary between the furnace wall and the rear flue wall, where the flow of force is concentrated when the boiler is started.

[Effect of idea]

本考案によれば、火炉壁と後部煙道壁境界の応
力の集中する個所のフイン終端部におけるフイン
底のアールを大きくとることができ、応力集中を
緩和したので、亀裂発生等の心配がなくなり、ボ
イラの安全性・信頼性を向上させることができ
る。 According to the present invention, it is possible to increase the radius of the fin bottom at the end of the fin where stress is concentrated at the boundary between the furnace wall and the rear flue wall, which alleviates stress concentration and eliminates concerns about cracking. , the safety and reliability of the boiler can be improved.

[Brief explanation of the drawing]

第１図は本考案の一実施例の側面図、第２図は
ボイラ炉壁の概念を示す側面図、第３図は従来の
炉壁の側面図である。１１……管、１２……フイン、１４……広巾
部、１５……フイン底、１６……管曲げ部。 FIG. 1 is a side view of an embodiment of the present invention, FIG. 2 is a side view showing the concept of a boiler furnace wall, and FIG. 3 is a side view of a conventional furnace wall. 11...Pipe, 12...Fin, 14...Wide part, 15...Fin bottom, 16...Pipe bending part.

Claims

[Scope of utility model registration request]

Near the lower end of the boundary between the boiler furnace wall and the rear flue wall, a pipe bend is provided in the pipe on the rear flue side, and the pipe bends are arranged at successively different heights to form a wide part of the pipe pitch. A boiler furnace wall characterized in that a fin end portion having both end faces attached to the tube is located in that portion.