JPS58182094A

JPS58182094A - Finned tube type heat exchanger

Info

Publication number: JPS58182094A
Application number: JP6664282A
Authority: JP
Inventors: Takeshi Aizawa; 相沢　毅
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1982-04-20
Filing date: 1982-04-20
Publication date: 1983-10-24

Abstract

PURPOSE:To utilize the part with high heat transfer characteristics at upstream side of a tube and eliminate the generation of dead water region at downstream side and consequently obtain the finned tube heat exchanger with high heat transfer characteristics by a structure wherein the radius of curvature of the section of the tube with a large number of fins at its outside in the heat exchanger is made larger at the upstream side than at the downstream side with respect to the direction of air flow. CONSTITUTION:The sectional form of the tube is made so that the radius of curvature R1 of the section of the pipe at the upstream side with respect to the air flow is made larger than the radius of curvature R2 of the section of the pipe at the downstream side. Owing to the structure as mentioned above, the air flow around the tube runs along the tube wall to the downstream of the tube, resulting in nearly eliminating the generation of stagnation point. Accordingly, the upstream part 41, which has high heat transfer characteristics, extends itself to the wake of the tube. Furthermore, because the upstream side the tube is the part especially having high heat transfer characteristics, said part in the upstream side is made larger than that in downstream side so as to keep the heat transfer characteristics as high as possible.

Description

【発明の詳細な説明】本発明はパイプの外側に多数のフィンを有するフィンチ
ー−ブ式熱交換器に関するものであって、その目的とす
るところは、伝熱効率の高いフィンチー−ブ式熱交換器
を提供するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fin-chive heat exchanger having a large number of fins on the outside of a pipe, and an object thereof is to provide a fin-chive heat exchanger with high heat transfer efficiency. It provides:

従来のフィンチー−ブ式熱交換器は第１図に示すように
円管１に多数のフィン２を有するものであり、このフィ
ンチューブ式熱交換器の円管周りの空気の流れをみると
、第２図の矢印のように空気の流れに対する円管の上流
側は、空気は円管１に沿って流れるが下流側では空気の
流れが円管１より離れて、空気の流れのよどんだ止水域
３ができる。しだがって、伝熱特性の良いところは円管
１の一］二流部４で、下流側はきわめて伝熱特性か悪い
ものであった。この伝熱特性の悪さを改善する／こめ伝
熱管を流れに対して上流と後流が対称な偏平管丑たは楕
円管とするものもあるが、この場合は第４図のように流
れに対して伝熱特性の最も良くなるＪ二流部が小さくな
るため全体としての伝熱効率は大して良くならなかった
。A conventional fin-tube heat exchanger has a circular tube 1 with a large number of fins 2 as shown in Fig. 1. Looking at the air flow around the circular tube of this fin-tube heat exchanger, As shown by the arrow in Figure 2, on the upstream side of the circular pipe with respect to the air flow, the air flows along the circular pipe 1, but on the downstream side, the air flow separates from the circular pipe 1 and the air flow stops. Water area 3 is created. Therefore, the heat transfer characteristics were good in the second flow section 4 of the circular tube 1, and the downstream side had extremely poor heat transfer characteristics. To improve this poor heat transfer characteristic, some heat transfer tubes are made of flat tubes or oval tubes whose upstream and downstream sides are symmetrical with respect to the flow. On the other hand, since the J second flow section where the heat transfer characteristics are the best becomes smaller, the overall heat transfer efficiency does not improve much.

本発明は」二記のように従来フィンチー−ブ式熱交換器
の伝熱特性を改善するものである。The present invention improves the heat transfer characteristics of the conventional fin-chive heat exchanger as described in Section 2.

そのための構成として、本発明は、パイプの外側に多数
のフィンを有するフィンチー−−ブ式熱交換器のパイプ
断面形状を空気の流れ方向に対して下流側のパイプ断面
半径より上流側のパイプ断面半径を大きくしたものであ
る。As a configuration for this purpose, the present invention provides a fin-chive type heat exchanger having a large number of fins on the outside of the pipe, with a pipe cross-sectional shape that is on the upstream side of the pipe cross-sectional radius on the downstream side with respect to the air flow direction. It has a larger radius.

以下、本発明の一実施例につき図面の第５図。Hereinafter, FIG. 5 of the drawings for one embodiment of the present invention will be described.

第６図に沿って説明する。This will be explained along with FIG.

第６図は本発明のフインチー−ブ式熱交換器のパイプ断
面形状であって、１１はノくイブ、１２はフィンで、矢
印Ａは空気の流れ方向を示している。FIG. 6 shows a cross-sectional shape of a pipe of a fin-cheve heat exchanger according to the present invention, where 11 is a knob, 12 is a fin, and arrow A indicates the direction of air flow.

すなわち、本発明のパイプ断面形状としては、空気の流
れに対して上流側のパイプ断面の半径Ｒ１を下流側のパ
イプ断面半径Ｒ２より大きくしたものである。That is, the pipe cross-sectional shape of the present invention is such that the radius R1 of the pipe cross-section on the upstream side with respect to the air flow is larger than the cross-sectional radius R2 of the pipe cross-section on the downstream side.

この構成においてパイプ周りの空気の流れをみると第５
図のように、空気の流れはパイプの下流捷で管壁に沿っ
て流れることになるので、空気の流れるよどみ点は殆ん
どなくなる。したがって第６図のように伝熱特性の良い
部分の上流部４１がパイプの後流に１で及んでいる。さ
らにパイプの上流側は特に伝熱特性の良いところである
ので、この部分は下流側よりも大きくして、できるだけ
伝熱特性を良く保つようにしであるものである。Looking at the air flow around the pipe in this configuration, the fifth
As shown in the figure, the air flows along the pipe wall at the downstream end of the pipe, so there are almost no stagnation points. Therefore, as shown in FIG. 6, the upstream portion 41 of the portion with good heat transfer characteristics extends downstream of the pipe. Furthermore, since the upstream side of the pipe has particularly good heat transfer characteristics, this portion is made larger than the downstream side in order to keep the heat transfer characteristics as good as possible.

以上のように、本発明によれば、パイプの上流側では従
来のように伝熱特性の高い部分を利用し、さらに下流側
は従来のような止水域の発生がないので、従来に比して
きわめて伝熱特性の高いフインチー−ブ式熱交換器を揚
供できるものである。As described above, according to the present invention, on the upstream side of the pipe, a portion with high heat transfer characteristics is used as in the conventional case, and furthermore, on the downstream side, there is no cutoff area as in the conventional case, so compared to the conventional method. It is possible to provide a fin-chive heat exchanger with extremely high heat transfer characteristics.

[Brief explanation of drawings]

第１図は従来のフィンチューブ式熱交換器の要部斜視図
、第２図は同フィンチューブ式熱交換器の円管周りの空
気の流れを示す説明図、第３図は同フィンチューブ式熱
交換器の円管周りの伝熱特性を示す説明図、第４図は偏
平管を用いた従来のフィンチ＝−プ式熱交換器の伝熱特
性を示す説明図、第５図は本発明の一実施例におけるフ
ィンチー。−ブ式熱交換器のパイプ周りの空気の流れを
示す説明図、第６図は同フィンチーープ式熱交換器のパ
イプ周りの伝熱特性を示す説明図である。１１・・・・・・パイプブ、１２・・・・・フィン、Ｒ
１・・・・・・」二流側のパイプ断面の半径、Ｒ２・・
・・・・下流側のパイプ断面の半径。代理人の氏名　弁理士　中　尾　敏　男　ほか１名第１
図第２図第３図４２第４図第５図２第６図２Figure 1 is a perspective view of the main parts of a conventional fin-tube heat exchanger, Figure 2 is an explanatory diagram showing the air flow around the circular tubes of the fin-tube heat exchanger, and Figure 3 is the same fin-tube heat exchanger. An explanatory diagram showing the heat transfer characteristics around the circular tubes of the heat exchanger, Fig. 4 is an explanatory diagram showing the heat transfer characteristics of a conventional finch type heat exchanger using flat tubes, and Fig. 5 is an explanatory diagram showing the heat transfer characteristics around the circular tube of the heat exchanger. Finchy in one embodiment. FIG. 6 is an explanatory diagram showing the flow of air around the pipes of the fin-cheap heat exchanger, and FIG. 6 is an explanatory diagram showing the heat transfer characteristics around the pipes of the fin-cheap heat exchanger. 11...Pipe tube, 12...Fin, R
1..." Radius of the pipe cross section on the second flow side, R2...
...Radius of the pipe cross section on the downstream side. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 42 Figure 4 Figure 5 Figure 2 Figure 6 2

Claims

[Claims]

The pipe cross-sectional shape of a fin-tube heat exchanger that has a large number of fins on the outside of the pipe is a finch-tube heat exchanger in which the pipe cross-sectional radius on the downstream side is larger than the pipe cross-sectional radius on the downstream side in the air flow direction. formula