JPS61110891A - Heat exchanger - Google Patents
Heat exchangerInfo
- Publication number
- JPS61110891A JPS61110891A JP23072384A JP23072384A JPS61110891A JP S61110891 A JPS61110891 A JP S61110891A JP 23072384 A JP23072384 A JP 23072384A JP 23072384 A JP23072384 A JP 23072384A JP S61110891 A JPS61110891 A JP S61110891A
- Authority
- JP
- Japan
- Prior art keywords
- heat transfer
- refrigerant
- dryness
- tube
- groove
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F1/00—Tubular elements; Assemblies of tubular elements
- F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
- F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Geometry (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は空気調和機や冷凍機等に用いる熱交換器に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat exchanger used in air conditioners, refrigerators, etc.
従来例の構成とその問題点
冷媒等の作動流体が伝熱管内を相変化しながら流動する
熱交換器としては、従来、第１図に示すようなフィン付
熱交換器が用いられている。これは一定間隔に並設した
多数のフィン１と、前記フィン１を貫通して配列した複
数の伝熱管２から構成されており、伝熱管２内の冷媒と
管外の空気の間で熱交換が行われる。図中矢印３は冷媒
の流動方向を示す。伝熱管２としては、第２図に示すよ
うに、溝深さｈが一定であるらせん浦４を管内壁に設け
た管内らせん溝付管が用いられている。BACKGROUND ART Conventionally, a finned heat exchanger as shown in FIG. 1 has been used as a heat exchanger in which a working fluid such as a refrigerant flows through heat transfer tubes while undergoing a phase change. This consists of a large number of fins 1 arranged in parallel at regular intervals and a plurality of heat transfer tubes 2 arranged through the fins 1, and heat exchange between the refrigerant inside the heat transfer tubes 2 and the air outside the tubes. will be held. Arrow 3 in the figure indicates the flow direction of the refrigerant. As the heat exchanger tube 2, as shown in FIG. 2, an internal spiral grooved tube is used in which a spiral groove 4 having a constant groove depth h is provided on the inner wall of the tube.
この管内らせん溝付管は溝４を設けることによって１Ｍ
発熱伝達の場合は管底部の液冷媒が毛細管現象によって
溝内を上昇し、管内伝熱面に形成される冷媒液膜の平均
厚さが薄くなり、凝縮熱伝達の場合は凝縮液が表面張力
の作用で溝底部に集まり、管内伝熱面に生成される凝縮
液膜の平均厚さが薄くなり、共に伝熱性能が向上すると
言われていた。By providing the groove 4, this internal spiral grooved tube can be made with 1M
In the case of heat transfer, the liquid refrigerant at the bottom of the tube rises in the groove due to capillary action, and the average thickness of the refrigerant liquid film formed on the heat transfer surface in the tube becomes thinner, and in the case of condensation heat transfer, the condensed liquid rises due to the surface tension. It was said that the average thickness of the condensate film that collects at the bottom of the groove and is generated on the heat transfer surface inside the tube becomes thinner due to this action, and that this improves heat transfer performance.
しかし、我々の経験によれば、例えば蒸発熱伝達の場合
に管内全伝熱面に薄い厚さの冷媒液膜が形成され、著し
い伝熱促進効果が得られるのは冷媒の乾き度が大きい、
すなわち蒸発過程の後期だけである。一方、蒸発過程の
初期においては、冷媒の乾き度は小さく、管内の液冷媒
の流量が多い。However, according to our experience, for example, in the case of evaporative heat transfer, a thin refrigerant liquid film is formed on the entire heat transfer surface in the tube, and a significant heat transfer promotion effect can be obtained if the refrigerant is highly dry.
That is, only in the latter stages of the evaporation process. On the other hand, at the beginning of the evaporation process, the dryness of the refrigerant is low and the flow rate of the liquid refrigerant in the pipes is large.
そのため、液冷媒は容易に溝を埋めてしまい、溝を乗り
越えて流動する。したがって、前述のような蒸発メカニ
ズムによる著しい伝熱促進効果は望めない。以上のこと
から、蒸発器の伝熱性能を飛躍的に向上させるためには
、冷媒の乾き度が大きい領域における著しい伝熱促進効
果をより一層有効利用しなければならないという問題が
ある。Therefore, the liquid refrigerant easily fills the groove and flows over the groove. Therefore, a significant heat transfer promoting effect due to the evaporation mechanism as described above cannot be expected. From the above, in order to dramatically improve the heat transfer performance of the evaporator, there is a problem that the remarkable heat transfer promoting effect in the region where the degree of dryness of the refrigerant is large must be utilized more effectively.
一方、管内の作動流体が単相流の場合管内らせん溝付管
の伝熱性能は、前述の管内の作動流体が二相流の場合の
伝熱性能よりはるかに小さく、管内壁が平滑な平滑管の
単相流伝熱性能にほとんど等しい。すなわち、管内の作
動流体が単相流の場合には溝の効果は僅かである。以上
のことから、単相流域に管内らせん溝付管を用いること
はあまり効果的ではない。On the other hand, when the working fluid inside the pipe is a single-phase flow, the heat transfer performance of the spiral grooved pipe inside the pipe is much lower than the heat transfer performance when the working fluid inside the pipe is two-phase flow. Almost equal to the single-phase flow heat transfer performance of pipes. That is, when the working fluid in the pipe is a single-phase flow, the effect of the grooves is small. From the above, it is not very effective to use a pipe with internal spiral grooves in a single-phase flow area.
発明の目的
本発明は上記従来の欠点を解消するものであシ、冷媒の
乾き度が大きな領域における管内らせん溝付管の伝熱性
能を著しく向上させた高性能な熱交換器を提供すること
を目的とする。OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and provides a high-performance heat exchanger that significantly improves the heat transfer performance of a spirally grooved tube in a region where the degree of dryness of the refrigerant is large. With the goal.
発明の構成
本発明の熱交換器は、伝熱管の管内を相変化する流体の
流路とし、前記伝熱管の管内壁に溝深さが異なる少なく
とも２種類のらせん溝を設け、前記らせん溝の溝深さを
管内流体の低乾き度域で小さく、高乾き度域で大きくし
たものである。Structure of the Invention The heat exchanger of the present invention includes a heat exchanger tube in which the inside of the heat exchanger tube is a flow path for a phase-changing fluid, and at least two types of helical grooves having different groove depths are provided on the inner wall of the heat exchanger tube. The groove depth is small in the low dryness region of the fluid in the pipe and increased in the high dryness region.
実施例の説明
以下、本発明の一実施例について第３図〜第５図を参照
しながら説明する。DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 to 5.
第３図は本発明の一実施例の蒸発器の断面図である。こ
の第３図において、一定間隔に並設した多数のフィン６
と、前記フィン６を貫通して配列した複数の伝熱管６，
７，８．９および前記各伝熱管６〜９を互いに結合する
Ｕ字形ペンド１０より蒸発器が構成されている。管内を
矢印１１方向に冷媒が流動し、管外のフィン６間を空気
が流動して熱交換が行われる。そして、単相の液冷媒お
よび冷媒蒸気が流動する伝熱管６および９は管内壁面が
平滑な平滑管である。また、蒸発熱伝達が行われる伝熱
管７．８の管内壁にはそれぞれ第４図に示すように断面
が三角形状のらせん４１２゜１３が設けてあり、冷媒乾
き度の小さな領域の伝熱管７のらせん溝１２の溝深さｈ
ｌは小さく（例えばｈｌ ＝０．１５ｍｍ ） 、乾き
度の大きな領域の伝熱管８のらせん溝１３の溝深さＲ２
はｍ深さｈｌ よりかなり大きく（例えばｈ、２−０
．２５ｍｍ） ｌ、である。FIG. 3 is a sectional view of an evaporator according to an embodiment of the present invention. In FIG. 3, a large number of fins 6 are arranged in parallel at regular intervals.
and a plurality of heat transfer tubes 6 arranged through the fins 6,
7, 8.9 and a U-shaped pend 10 that connects each of the heat exchanger tubes 6 to 9 to each other, an evaporator is constructed. Refrigerant flows inside the tube in the direction of arrow 11, and air flows between the fins 6 outside the tube to perform heat exchange. The heat transfer tubes 6 and 9 through which single-phase liquid refrigerant and refrigerant vapor flow are smooth tubes with smooth inner wall surfaces. Further, as shown in FIG. 4, spirals 412° 13 having a triangular cross section are provided on the inner walls of the heat exchanger tubes 7 and 8 where evaporative heat transfer takes place. Groove depth h of the spiral groove 12
l is small (for example, hl = 0.15 mm), and the groove depth R2 of the helical groove 13 of the heat exchanger tube 8 in the region of high dryness is
is much larger than m depth hl (e.g. h, 2-0
．． 25mm) l.
なお１４は側板である。Note that 14 is a side plate.
このような構成であるだめに次のような作用と効果を生
じる。Such a configuration results in the following actions and effects.
単相の液冷媒および冷媒蒸気が流動する伝熱管６および
９を管内壁面が平滑な平滑管としているため、前述の単
相流域では平滑管６，９と管内らせん溝付管の伝熱性能
はほとんど等しいという理由から、伝熱管の伝熱性能を
減少させることなく、伝熱管加工費を安く、すなわち安
価な蒸発器とすることができる。Since the heat transfer tubes 6 and 9 through which single-phase liquid refrigerant and refrigerant vapor flow are smooth tubes with smooth inner wall surfaces, the heat transfer performance of the smooth tubes 6 and 9 and the spiral grooved tube in the tube in the above-mentioned single-phase region is as follows. Because they are almost equal, the processing cost of the heat exchanger tubes is low, without reducing the heat transfer performance of the heat exchanger tubes, that is, an inexpensive evaporator can be obtained.
次に、冷媒の流動状態が液冷媒と冷媒蒸気が同時に流れ
る二相流状態のときの、以下の実験条件下での、各種伝
熱管の蒸発伝熱性能に関する実験結果を第６図に示す。Next, FIG. 6 shows experimental results regarding the evaporative heat transfer performance of various heat transfer tubes under the following experimental conditions when the flow state of the refrigerant is a two-phase flow state in which liquid refrigerant and refrigerant vapor flow simultaneously.
使用冷媒・・・・・・Ｒ２２
蒸発温度・・・・・・５℃
冷媒の重量流量・・・・・・２５ｏ１ｑ／ｌｎ”・Ｓ熱
流束・・・・・・６０ｏｏｋＣ＆Ｊ／ｍＩ−ｈなお、縦
軸は各伝熱管の熱伝達率、横軸は冷媒の乾き度である。Refrigerant used: R22 Evaporation temperature: 5°C Weight flow rate of refrigerant: 25o1q/ln"・S Heat flux: 60ookC&J/mI-h The vertical axis is the heat transfer coefficient of each heat transfer tube, and the horizontal axis is the dryness of the refrigerant.
冷媒の乾き度が大きくなるにつれて、平滑管と管内らせ
ん溝付管の熱伝達率の差が大きくなる。つまり、乾き度
が大きいほど管内らせん溝による伝熱促進効果が非常に
著しくなる。As the dryness of the refrigerant increases, the difference in heat transfer coefficient between the smooth tube and the spirally grooved tube increases. In other words, the greater the degree of dryness, the more significant the effect of promoting heat transfer by the internal spiral grooves becomes.
また、冷媒の乾き度が小さな領域では管内らせん溝付管
の婢深さの影響はほとんどないが、乾き度が犬きくなり
冷媒蒸気量が増加するにつれて溝深さが大きいほど伝熱
性能は著しく増加する。一方、冷媒による圧力損失は溝
深さが大きいほど大きくなっている。しかしながら、冷
媒の乾き度が大きな領域における溝深さの増加による圧
力損失の増加の割合は上記の熱伝達率の増加の割合と比
較して小さな値である。In addition, in areas where the degree of dryness of the refrigerant is small, the depth of the spirally grooved pipe inside the tube has almost no effect, but as the degree of dryness becomes extremely dry and the amount of refrigerant vapor increases, the heat transfer performance becomes more significant as the depth of the groove increases. To increase. On the other hand, the pressure loss due to the refrigerant increases as the groove depth increases. However, the rate of increase in pressure loss due to the increase in groove depth in a region where the dryness of the refrigerant is large is a small value compared to the rate of increase in the heat transfer coefficient described above.
上記の実験結果に基いて、本実施例では冷媒の乾き度が
小さな領域の伝熱管７には溝深さが小さならせん溝１２
を設けている。冷媒の乾き度が小さく管内の液冷媒の流
量が多い場合には、液冷媒は溝に沿って流れるのではな
く、溝を乗り越えながら流れている。そのため、溝深さ
が小さならせん溝付管を用いることにより、伝熱性能を
低下させることなく冷媒による圧力損失を減少させるこ
とができる。Based on the above experimental results, in this example, the heat exchanger tube 7 in the region where the dryness of the refrigerant is small has a spiral groove 12 with a small groove depth.
has been established. When the degree of dryness of the refrigerant is low and the flow rate of the liquid refrigerant in the pipe is large, the liquid refrigerant does not flow along the grooves, but flows over the grooves. Therefore, by using a spiral grooved tube with a small groove depth, pressure loss due to the refrigerant can be reduced without deteriorating heat transfer performance.
また、本実施例では冷媒の乾き度が大きな領域の伝熱管
８には溝深さが大きならせん溝１３を設けている。冷媒
の乾き度が大きくなり管内の液冷媒の流量が少くなるに
つれて、らせん溝による毛細管現象により管内の冷媒の
流動状態は環状流あるいは環状噴霧流に遷移しやすくな
り、管内の全溝内面上に非常に薄い厚さの冷媒液膜が形
成され、伝熱性能が著しく向上する。したがって、らせ
ん溝付管において溝深さが大きいほど、より広い溝内面
に、さらに薄い冷媒液膜が形成されることになり、伝熱
性能を大幅に向上させることができる。Further, in this embodiment, the helical grooves 13 having a large groove depth are provided in the heat exchanger tubes 8 in regions where the degree of dryness of the refrigerant is large. As the dryness of the refrigerant increases and the flow rate of the liquid refrigerant in the tube decreases, the flow state of the refrigerant in the tube tends to transition to an annular flow or an annular spray flow due to the capillary phenomenon caused by the spiral groove, and the flow state of the refrigerant in the tube tends to change to an annular flow or an annular spray flow, and the flow state of the refrigerant in the tube tends to change to an annular flow or an annular spray flow, and the flow state of the refrigerant in the tube tends to change to an annular flow or an annular spray flow. A very thin refrigerant liquid film is formed, which significantly improves heat transfer performance. Therefore, the larger the groove depth in the spirally grooved tube, the thinner the refrigerant liquid film is formed on the wider inner surface of the groove, and the heat transfer performance can be significantly improved.
なお、上記実施例の管内らせん溝付管７．８には、らせ
ん溝と１〜て断面が三角形状の溝を設けたが、三角形以
外の多角形の断面形状を有する溝を設けても同様な効果
が得られることは言うまでもない。また、らせん溝の溝
深さＩｈ、とｈ２の２種類としたがそれ以上でも良いこ
とへ明らかである。In addition, although the internal spiral grooved tube 7.8 of the above embodiment was provided with a groove having a triangular cross section as a spiral groove, the same effect can be obtained by providing a groove having a polygonal cross section other than a triangle. Needless to say, the effect can be obtained. In addition, although there are two types of groove depths of the spiral groove, Ih and h2, it is obvious that more depths may be used.
また本発明は凝縮熱伝達においても蒸発熱伝達の場合と
同様の効果を発揮する。すなわち、冷媒の乾き度が大き
な領域の伝熱管に溝深さが大きならせん溝を設けること
により、管内の全溝内面に生成される凝縮液膜の平均厚
さを非常に薄くし、伝熱性能を著しく向上させることが
できる。Further, the present invention exhibits the same effect in condensation heat transfer as in evaporative heat transfer. In other words, by providing spiral grooves with a large groove depth in heat transfer tubes in areas where the dryness of the refrigerant is large, the average thickness of the condensate film that is generated on the inner surface of all grooves in the tube is extremely thin, improving heat transfer performance. can be significantly improved.
発明の効果
以上のように本発明の熱交換器は、伝熱管の管内金相変
化する流体の流路とし、前記伝熱管の管内壁に溝深さが
異なる少なくとも２種類のらせん溝を設け、前記らせん
溝の溝深さを管内流体の低乾き度域で小さく、高乾き度
域で大きくしたものであるから、高乾き度域において管
内の全溝内面上に非常に薄い厚さの冷媒液膜を形成する
ことができ、熱交換器の伝熱性能を著しく向上させるこ
とが可能であり、その工業的効果は大なるものがある。Effects of the Invention As described above, the heat exchanger of the present invention includes a heat exchanger tube having a flow path for a fluid that undergoes a metal phase change in the tube, and at least two types of helical grooves with different groove depths provided on the inner wall of the heat exchanger tube, Since the groove depth of the spiral groove is small in the low dryness region of the fluid in the pipe and large in the high dryness region, the refrigerant liquid has a very thin thickness on the inner surface of all the grooves in the pipe in the high dryness region. It is possible to form a film and to significantly improve the heat transfer performance of a heat exchanger, which has great industrial effects.
第１図は従来のフィン付熱交換器の斜視図、第２図（ａ
）および（ｂ）は同フィン付熱交換器の管内らせん溝付
管の一部欠截正面図および半裁側断面図、第３図は本発
明の一実施例を示す蒸発器の一部欠截正面図、＄４図（
２Ｌ）および（ｂ）は同蒸発器の管内らせん溝付管７の
一部欠截正面図および半裁側断面図、第４図（０）およ
び（ｄ）は同蒸発器の管内らせん溝付管８の一部欠截正
面図および半裁側断面図、第５図は伝熱管の蒸発性能実
験の結果を示す特性図である。
５・・・・・・フィン、６．了、８，９・・・・・・伝
熱管、１２．１３・・・・・・らせん溝。
代理人の氏名 弁理士 中 尾 敏 男 ほか１名第１
図
第２図
（ａ）（ｂ）
第３図
第 、 図 （リ
（ｂ〕（リ
（ｄ、）
第５図
ａさ皮Figure 1 is a perspective view of a conventional finned heat exchanger, and Figure 2 (a
) and (b) are a partially cut-away front view and a half-cut side sectional view of a spiral grooved tube inside the finned heat exchanger, and FIG. 3 is a partially cut-away side view of an evaporator showing an embodiment of the present invention. Front view, $4 figure (
2L) and (b) are partially cutaway front views and half-cut side sectional views of the internal spiral grooved tube 7 of the same evaporator, and FIGS. 4(0) and (d) are the internal spiral grooved tube of the same evaporator. FIG. 5 is a characteristic diagram showing the results of an evaporation performance experiment of the heat exchanger tube. 5...Fin, 6. Completed, 8,9... Heat exchanger tube, 12.13... Spiral groove. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 2 (a) (b) Figure 3
(b)
(d,) Figure 5 a.
Claims (1)
の管内壁に溝深さが異なる少なくとも２種類のらせん溝
を設け、前記らせん溝の溝深さを管内流体の低乾き変域
で小さく、高乾き度域で大きくした熱交換器。The inside of the heat transfer tube is a flow path for a phase-changing fluid, and at least two types of helical grooves with different groove depths are provided on the inner wall of the heat transfer tube, and the groove depth of the helical groove is set to a low dryness range of the fluid in the tube. A heat exchanger that is small in size and made larger in high dryness areas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23072384A JPS61110891A (en) | 1984-11-01 | 1984-11-01 | Heat exchanger |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23072384A JPS61110891A (en) | 1984-11-01 | 1984-11-01 | Heat exchanger |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61110891A true JPS61110891A (en) | 1986-05-29 |
| JPH0445753B2 JPH0445753B2 (en) | 1992-07-27 |
Family
ID=16912293
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23072384A Granted JPS61110891A (en) | 1984-11-01 | 1984-11-01 | Heat exchanger |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61110891A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63172894A (en) * | 1987-01-12 | 1988-07-16 | Matsushita Refrig Co | Heat exchanger |
| JPWO2013084508A1 (en) * | 2011-12-07 | 2015-04-27 | パナソニックＩｐマネジメント株式会社 | Finned tube heat exchanger |
-
1984
- 1984-11-01 JP JP23072384A patent/JPS61110891A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63172894A (en) * | 1987-01-12 | 1988-07-16 | Matsushita Refrig Co | Heat exchanger |
| JPWO2013084508A1 (en) * | 2011-12-07 | 2015-04-27 | パナソニックＩｐマネジメント株式会社 | Finned tube heat exchanger |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0445753B2 (en) | 1992-07-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6056048A (en) | Falling film type heat exchanger tube | |
| US6412549B1 (en) | Heat transfer pipe for refrigerant mixture | |
| JP2002372390A (en) | Heat exchanger tube for falling film evaporator | |
| US5590711A (en) | Heat transfer tube for absorber | |
| JPH06185885A (en) | Flat multi-holed condensing and heat transfer pipe | |
| JPS60216190A (en) | Heat transfer pipe and manufacture thereof | |
| JPS61110891A (en) | Heat exchanger | |
| JPH11257888A (en) | Heat transfer pipe for flow-down liquid film type evaporator | |
| CA1302395C (en) | Heat exchanger tube having minute internal fins | |
| EP0518312A1 (en) | Heat transfer tube with grooved inner surface | |
| JPS61114092A (en) | Heat exchanger | |
| JP3199636B2 (en) | Heat transfer tube with internal groove | |
| JPH07109354B2 (en) | Heat exchanger | |
| JPH05322477A (en) | Boiling heat transfer surface | |
| JPS5938596A (en) | Heat exchanger | |
| JPH07190663A (en) | Heating tube | |
| JPH05133692A (en) | Evaporator | |
| JP2802184B2 (en) | Heat transfer tube for condenser | |
| JPS62248995A (en) | Evaporator | |
| JPS6049837B2 (en) | Heat exchanger tube for condenser | |
| JP2663776B2 (en) | Condenser | |
| JP3417825B2 (en) | Inner grooved pipe | |
| JPH02143094A (en) | Heat exchanger equipped with heat transfer tube | |
| JPS63172891A (en) | Heat exchanger | |
| JPH0615951B2 (en) | Heat transfer tube with internal groove |