JP2012052704A - Heat transfer tube with grooved inner surface and cross fin tube type heat exchanger for evaporator - Google Patents

Heat transfer tube with grooved inner surface and cross fin tube type heat exchanger for evaporator Download PDF

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JP2012052704A
JP2012052704A JP2010193697A JP2010193697A JP2012052704A JP 2012052704 A JP2012052704 A JP 2012052704A JP 2010193697 A JP2010193697 A JP 2010193697A JP 2010193697 A JP2010193697 A JP 2010193697A JP 2012052704 A JP2012052704 A JP 2012052704A
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tube
heat transfer
transfer tube
fin
grooved heat
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Takahiko Mizuta
貴彦 水田
Naoe Sasaki
直栄 佐々木
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Sumitomo Light Metal Industries Ltd
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Abstract

PROBLEM TO BE SOLVED: To provide a cross fin tube type heat exchanger for an evaporator that uses a coolant mainly comprising carbon dioxide and has superior evaporation heat transfer characteristics.SOLUTION: A heat transfer tube with a grooved inner surface for the cross fin tube type heat exchanger for an evaporator has an aluminum fin and the heat transfer tube with an grooved inner surface assembled to the aluminum fin and uses the coolant mainly comprising carbon dioxide. The heat transfer tube with the grooved inner surface is characterized in that an inner surface groove satisfies the following relation (1): 0.06≤t/D≤0.095 wherein a bottom thickness of the heat transfer tube with the grooved inner surface is t(mm) and a tube outside diameter is D(mm) and, further, the inner surface groove satisfies the following relations (2), (3) and (4): 0.07≤Wg≤0.15 (2), 0.5≤Wg/d≤0.8 (3), 0<α≤15 (4), wherein an inner surface groove depth is d (mm), an inner surface groove width is Wg (mm) and an inner surface groove side surface angle is α(°).

Description

本発明は、二酸化炭素を主成分とする冷媒を用いる冷凍機、空調機、給湯機等の蒸発器用のクロスフィンチューブ型熱交換器及びその製造に用いられる内面溝付伝熱管に関する。   The present invention relates to a cross fin tube type heat exchanger for an evaporator such as a refrigerator, an air conditioner, and a hot water heater using a refrigerant mainly composed of carbon dioxide, and an internally grooved heat transfer tube used for the manufacture thereof.

地球温暖化ガスである冷媒ガスの排出抑制の観点から、熱交換器の冷媒として、フロン系冷媒に替わり、二酸化炭素冷媒に代表される自然冷媒の使用が検討されてきている。   From the viewpoint of suppressing the discharge of refrigerant gas, which is a global warming gas, the use of natural refrigerants typified by carbon dioxide refrigerants as a refrigerant for heat exchangers has been studied in place of CFC refrigerants.

このような二酸化炭素冷媒が使用される熱交換器のうち、蒸発器用の熱交換器としては、従来のフロン系の場合と同様、アルミニウムフィンと銅製伝熱管を組み付けたクロスフィンチューブ型熱交換器が主流であり、該銅製伝熱管としては、内面溝付伝熱管が使用されてきている。   Among the heat exchangers using such carbon dioxide refrigerant, as a heat exchanger for an evaporator, a cross fin tube type heat exchanger in which aluminum fins and copper heat transfer tubes are assembled as in the case of conventional chlorofluorocarbons. As the copper heat transfer tube, an internally grooved heat transfer tube has been used.

そして、従来より、このようなクロスフィンチューブ型熱交換器は、以下のような工程を経て製造されている。先ず、プレス加工等により、所定の組み付け孔が複数形成されたアルミニウムフィンを成形する。次いで、得られたアルミニウムフィンを積層した後、該組み付け孔の内部に、別に作製した銅製伝熱管を挿通する。次いで、該銅製伝熱管をアルミニウムフィンに拡管して固着し、ヘアピン曲げ加工を施した側とは反対側の伝熱管端部に、Uベンド管をろう付け加工する工程を経て、クロスフィンチューブ型熱交換器を製造する。   And conventionally, such a cross fin tube type heat exchanger is manufactured through the following processes. First, an aluminum fin having a plurality of predetermined assembly holes is formed by pressing or the like. Subsequently, after laminating the obtained aluminum fins, a copper heat transfer tube prepared separately is inserted into the assembly hole. Next, the copper heat transfer tube is expanded and fixed to an aluminum fin, and a U-bend tube is brazed to the end of the heat transfer tube opposite to the side subjected to the hairpin bending process. Manufacture heat exchangers.

該クロスフィンチューブ型熱交換器に用いられる該銅製伝熱管には、内面溝付伝熱管が使用されてきている。   An internally grooved heat transfer tube has been used as the copper heat transfer tube used in the cross fin tube type heat exchanger.

例えば、特開2003−343942号公報(特許文献1)には、チューブ内を流れる二酸化炭素を蒸発させる蒸発器であって、前記チューブの通路断面形状は円形であり、かつ、前記チューブの内壁には、中心側に突出した複数個の突起部が設けられており、
数式1:0.5×d1.2682≦L≦2.09×d1.2682
前記チューブの通路長さ(L)と前記チューブの平均内径(d)とは、上記数式1に示される関係を有していることを特徴とする蒸発器が開示されている。
For example, Japanese Patent Application Laid-Open No. 2003-343492 (Patent Document 1) discloses an evaporator that evaporates carbon dioxide flowing in a tube, and the cross-sectional shape of the passage of the tube is circular, and the inner wall of the tube Is provided with a plurality of protrusions protruding to the center side,
Formula 1: 0.5 × d 1.2682 ≦ L ≦ 2.09 × d 1.2682
An evaporator is disclosed in which the passage length (L) of the tube and the average inner diameter (d) of the tube have the relationship shown in the above formula 1.

しかし、特許文献1に示す蒸発器では、内面溝付伝熱管が用いられているが、平滑管が用いられているものと比較して、管内熱伝達率は高いものの、単に、内面に溝加工を施しただけなので、管内熱伝達率は不十分であった。   However, in the evaporator shown in Patent Document 1, an internally grooved heat transfer tube is used. However, although the heat transfer coefficient in the tube is higher than that using a smooth tube, the inner surface is simply grooved. The heat transfer coefficient in the pipe was insufficient.

内面溝付伝熱管の管内熱伝達率を改善するものとして、例えば、特開2006−162100号公報(特許文献2)には、高圧冷媒を用いるクロスフィンチューブ式熱交換器を構成する伝熱管にして、管内面に多数の溝が管周方向に又は管軸に対して所定のリード角をもって延びるように形成されているとともに、それら溝間には、所定高さの内面フィンが形成されてなる銅又は銅合金製の内面溝付伝熱管において、管外径D(mm)、前記溝の形成部位における管壁厚となる底肉厚をt(mm)、前記溝の溝深さをd(mm)、管軸に対して垂直な断面における溝1個あたりの断面積をA(mm)としたときに、t/Dが0.041以上0.146以下であり、且つd/Aが0.75以上1.5以下であると共に、Nを前記溝の溝条数、Diを前記溝の溝底をつないで形成される管内径に相当する最大内径としたときに、N/Diが8以上24以下となるように構成したことを特徴とする高圧冷媒用内面溝付伝熱管が開示されている。 As an example of improving the heat transfer coefficient in a tube of an internally grooved heat transfer tube, for example, Japanese Patent Laid-Open No. 2006-162100 (Patent Document 2) discloses a heat transfer tube constituting a cross fin tube heat exchanger using a high-pressure refrigerant. In addition, a large number of grooves are formed on the inner surface of the tube so as to extend in the tube circumferential direction or with a predetermined lead angle with respect to the tube axis, and inner surface fins having a predetermined height are formed between the grooves. In an internally grooved heat transfer tube made of copper or copper alloy, the tube outer diameter D (mm), the bottom wall thickness to be the tube wall thickness at the groove formation site is t (mm), and the groove depth of the groove is d ( mm) and t / D is 0.041 or more and 0.146 or less, and d 2 / A, where A (mm 2 ) is the cross-sectional area per groove in the cross section perpendicular to the tube axis. Is not less than 0.75 and not more than 1.5, and N is a groove of the groove. The inner surface for high-pressure refrigerant, wherein N / Di is 8 or more and 24 or less, where Di is the maximum inner diameter corresponding to the inner diameter of the pipe formed by connecting the groove bottoms of the grooves. A grooved heat transfer tube is disclosed.

また、特開2002−90086号公報(特許文献3)には、アルミニウムフィンに、内面溝付伝熱管を組み付けて、クロスフィンチューブ型熱交換器を製造する際に、管内面の内面フィンが変形することを抑制することができる内面溝付伝熱管として、管内面に多数の溝が管周方向に又は管軸に対して所定のリード角をもって延びるように形成されていると共に、それらの溝間に、所定高さの内面フィンが形成されてなる内面溝付伝熱管にして、管外径が4mm〜10mmとされ、且つ前記溝の溝深さが0.10mm〜0.30mmとされると共に、前記溝の形成部位における管壁厚となる底肉厚(t)が、次式:t≦0.1248×D0.32782(但し、Dは管外径を示す)を満足するように、構成されていることを特徴とする内面溝付伝熱管が開示されている。 Japanese Patent Laid-Open No. 2002-90086 (Patent Document 3) discloses that an inner fin on the inner surface of a tube is deformed when a heat transfer tube with an inner groove is assembled on an aluminum fin to manufacture a cross fin tube heat exchanger. As an internally grooved heat transfer tube that can be suppressed, a large number of grooves are formed on the inner surface of the tube so as to extend in the circumferential direction of the tube or with a predetermined lead angle with respect to the tube axis. And an inner grooved heat transfer tube formed with inner fins of a predetermined height, the outer diameter of the tube being 4 mm to 10 mm, and the groove depth of the groove being 0.10 mm to 0.30 mm. The bottom wall thickness (t), which is the tube wall thickness at the groove forming site, satisfies the following formula: t ≦ 0.1248 × D 0.32782 (where D represents the outer diameter of the tube ), Inner surface characterized by being constructed A grooved heat transfer tube is disclosed.

特開2003−343942号公報(特許請求の範囲)JP 2003-343492 A (Claims) 特開2006−162100号公報(特許請求の範囲)JP 2006-162100 A (Claims) 特開2002−90086号公報(特許請求の範囲)JP 2002-90086 (Claims)

特許文献2の内面溝付伝熱管では、蒸発熱伝達特性が向上するものの、それでもなお、更なる蒸発熱伝達特性の向上が求められている。また、特許文献3の内面溝付伝熱管でも、同様に、更なる蒸発熱伝達特性の向上が求められている。   In the heat transfer tube with an inner surface groove of Patent Document 2, the evaporation heat transfer characteristic is improved, but still further improvement of the evaporation heat transfer characteristic is required. Similarly, the inner surface grooved heat transfer tube of Patent Document 3 is also required to further improve the evaporation heat transfer characteristics.

従って、本発明は、冷媒として、二酸化炭素を主成分とする冷媒を用いる蒸発器用のクロスフィンチューブ型熱交換器であって、蒸発熱伝達特性に優れる蒸発器用のクロスフィンチューブ型熱交換器を提供すること、及び蒸発熱伝達特性に優れる蒸発器用のクロスフィンチューブ型熱交換器を製造することができる内面溝付伝熱管を提供することにある。   Therefore, the present invention provides a cross-fin tube type heat exchanger for an evaporator using a refrigerant mainly composed of carbon dioxide as a refrigerant, the cross-fin tube type heat exchanger for an evaporator having excellent evaporative heat transfer characteristics. An object of the present invention is to provide an internally grooved heat transfer tube capable of producing a cross fin tube type heat exchanger for an evaporator having excellent evaporation heat transfer characteristics.

本発明者らは、上記従来技術における課題を解決すべく、鋭意研究を重ねた結果、内面溝付伝熱管の内面溝の幅を狭くし且つ内面溝の幅に対して内面溝の深さを深くすることにより、該内面溝がオープンキャビティーとして機能し、核沸騰を促進させるので、蒸発熱伝達特性に優れるクロスフィンチューブ型熱交換器が得られることを見出し、本発明を完成させるに至った。   As a result of intensive studies to solve the above-described problems in the prior art, the inventors narrowed the width of the inner surface groove of the inner surface grooved heat transfer tube and set the depth of the inner surface groove to the width of the inner surface groove. By deepening, the inner surface groove functions as an open cavity and promotes nucleate boiling, so that a cross fin tube type heat exchanger having excellent evaporation heat transfer characteristics can be obtained, and the present invention has been completed. It was.

すなわち、本発明(1)は、アルミニウムフィンと、該アルミニウムフィンに組み付けられている内面溝付伝熱管とを有し、二酸化炭素を主成分とする冷媒を用いる蒸発器用のクロスフィンチューブ型熱交換器用の内面溝付伝熱管であって、
該内面溝付伝熱管の底肉厚をt(mm)、管外径をD(mm)とするとき、下記式(1):
0.06≦t/D≦0.095 (1)
を満たし、
内面溝深さをd(mm)、内面溝幅をWg(mm)、内面溝側面角をα(°)とするとき、下記式(2)、(3)及び(4):
0.07≦Wg≦0.15 (2)
0.5≦Wg/d≦0.8 (3)
0<α≦15 (4)
の全てを満たす内面溝を有すること、
を特徴とする内面溝付伝熱管を提供するものである。
That is, the present invention (1) has an aluminum fin and an internally grooved heat transfer tube assembled to the aluminum fin, and a cross fin tube heat exchange for an evaporator using a refrigerant mainly composed of carbon dioxide. An internally grooved heat transfer tube
When the bottom wall thickness of the internally grooved heat transfer tube is t (mm) and the tube outer diameter is D (mm), the following formula (1):
0.06 ≦ t / D ≦ 0.095 (1)
The filling,
When the inner surface groove depth is d (mm), the inner surface groove width is Wg (mm), and the inner surface groove side surface angle is α (°), the following formulas (2), (3) and (4):
0.07 ≦ Wg ≦ 0.15 (2)
0.5 ≦ Wg / d ≦ 0.8 (3)
0 <α ≦ 15 (4)
Having an internal groove that satisfies all of
An internally grooved heat transfer tube is provided.

また、本発明(2)は、本発明(1)の内面溝付伝熱管を、アルミニウムフィンに挿通し、次いで、拡管率3〜9%で拡管することにより、該内面溝付伝熱管を該アルミニウムフィンに固着して得られることを特徴とする蒸発器用のクロスフィンチューブ型熱交換器を提供するものである。   Moreover, this invention (2) inserts this inner surface grooved heat exchanger tube of this invention (1) through an aluminum fin, and then expands the inner surface grooved heat exchanger tube by 3 to 9%. The present invention provides a cross fin tube type heat exchanger for an evaporator, which is obtained by being fixed to an aluminum fin.

本発明によれば、冷媒として、二酸化炭素を主成分とする冷媒を用いる蒸発器用のクロスフィンチューブ型熱交換器であって、蒸発熱伝達特性に優れる蒸発器用のクロスフィンチューブ型熱交換器を提供することができる。   According to the present invention, there is provided a cross fin tube type heat exchanger for an evaporator using a refrigerant mainly composed of carbon dioxide as a refrigerant, the cross fin tube type heat exchanger for an evaporator having excellent evaporative heat transfer characteristics. Can be provided.

内面溝付伝熱管(A)を用いて製造される蒸発器用のクロスフィンチューブ型熱交換器の形態例の模式図である。It is a schematic diagram of the form example of the cross fin tube type heat exchanger for evaporators manufactured using an internal grooved heat exchanger tube (A). 内面溝付伝熱管(A)及び内面溝付伝熱管(B)を、管軸方向に対して垂直な面で切ったときの断面図である。It is sectional drawing when an inner surface grooved heat exchanger tube (A) and an inner surface grooved heat exchanger tube (B) are cut by the surface perpendicular | vertical with respect to a tube-axis direction. 内面溝付伝熱管(A)及び内面溝付伝熱管(B)の断面のうちの内面フィンの一部分を拡大した図である。It is the figure which expanded a part of inner surface fin among the cross sections of an inner surface grooved heat exchanger tube (A) and an inner surface grooved heat exchanger tube (B). 内面溝付伝熱管(A)及び内面溝付伝熱管(B)の断面のうちの内面フィンの一部分を拡大した図である。It is the figure which expanded a part of inner surface fin among the cross sections of an inner surface grooved heat exchanger tube (A) and an inner surface grooved heat exchanger tube (B). 実施例及び比較例で製造した評価用のクロスフィンチューブ型熱交換器を示す断面図である。It is sectional drawing which shows the cross fin tube type heat exchanger for evaluation manufactured by the Example and the comparative example. 管内熱伝達率性能評価方法を示す図である。It is a figure which shows the heat-transfer coefficient performance evaluation method in a pipe | tube.

本発明の内面溝付伝熱管(A)は、アルミニウムフィンと、該アルミニウムフィンに組み付けられている内面溝付伝熱管(B)とを有し、二酸化炭素を主成分とする冷媒を用いる蒸発器用のクロスフィンチューブ型熱交換器用の内面溝付伝熱管(A)であって、
該内面溝付伝熱管の底肉厚をt(mm)、管外径をD(mm)とするとき、下記式(1):
0.06≦t/D≦0.095 (1)
を満たし、
該内面溝付伝熱管(A)の内面溝深さをd(mm)、内面溝幅をWg(mm)、内面溝側面角をα(°)とするとき、下記式(2)、(3)及び(4):
0.07≦Wg≦0.15 (2)
0.5≦Wg/d≦0.8 (3)
0<α≦15 (4)
の全てを満たす内面溝を有する内面溝付伝熱管である。
なお、本発明では、拡管前の内面溝付伝熱管を「内面溝付伝熱管(A)」と記載し、拡管後の内面溝付伝熱管を「内面溝付伝熱管(B)」と記載する。
The internally grooved heat transfer tube (A) of the present invention has an aluminum fin and an internally grooved heat transfer tube (B) assembled to the aluminum fin, and is used for an evaporator using a refrigerant mainly composed of carbon dioxide. An internally grooved heat transfer tube (A) for a cross fin tube type heat exchanger of
When the bottom wall thickness of the internally grooved heat transfer tube is t (mm) and the tube outer diameter is D (mm), the following formula (1):
0.06 ≦ t / D ≦ 0.095 (1)
The filling,
When the inner surface groove depth of the inner surface grooved heat transfer tube (A) is d (mm), the inner surface groove width is Wg (mm), and the inner surface groove side surface angle is α (°), the following equations (2), (3 ) And (4):
0.07 ≦ Wg ≦ 0.15 (2)
0.5 ≦ Wg / d ≦ 0.8 (3)
0 <α ≦ 15 (4)
It is an internal grooved heat transfer tube having an internal groove satisfying all of the above.
In the present invention, the internally grooved heat transfer tube before tube expansion is described as “inner surface grooved heat transfer tube (A)”, and the internally grooved heat transfer tube after tube expansion is described as “inner surface grooved heat transfer tube (B)”. To do.

該内面溝付伝熱管(A)は、該アルミニウムフィンと、該アルミニウムフィンに組み付けられている内面溝付伝熱管とを有し、二酸化炭素を主成分とする冷媒を用いる蒸発器用のクロスフィンチューブ型熱交換器の製造に用いられる内面溝付伝熱管であり、該アルミニウムフィンに挿通されて、次いで、拡管されることにより、該アルミニウムフィンに組み付けられる内面溝付伝熱管である。つまり、該内面溝付伝熱管(A)は、拡管前の内面溝付伝熱管である。また、該内面溝付伝熱管(B)は、該内面溝付伝熱管(A)を拡管することによって、該アルミニウムフィンに取り付けられた内面溝付伝熱管である。つまり、該内面溝付伝熱管(B)は、拡管後の内面溝付伝熱管である。   The inner surface grooved heat transfer tube (A) has the aluminum fin and the inner surface grooved heat transfer tube assembled to the aluminum fin, and a cross fin tube for an evaporator using a refrigerant mainly composed of carbon dioxide. It is an internally grooved heat transfer tube used for manufacturing a mold heat exchanger, and is an internally grooved heat transfer tube that is inserted into the aluminum fin and then expanded to be assembled to the aluminum fin. That is, the inner surface grooved heat transfer tube (A) is an inner surface grooved heat transfer tube before expansion. The inner surface grooved heat transfer tube (B) is an inner surface grooved heat transfer tube attached to the aluminum fin by expanding the inner surface grooved heat transfer tube (A). That is, the inner surface grooved heat transfer tube (B) is an inner surface grooved heat transfer tube after the expansion.

該内面溝付伝熱管(A)及び該内面溝付伝熱管(B)について、図1〜図4を参照して説明する。   The inner surface grooved heat transfer tube (A) and the inner surface grooved heat transfer tube (B) will be described with reference to FIGS.

図1は、該内面溝付伝熱管(A)を用いて製造される蒸発器用のクロスフィンチューブ型熱交換器の形態例の模式図である。図1中、蒸発器用のクロスフィンチューブ型熱交換器1は、アルミニウムフィン2と、内面溝付伝熱管(B)3とを有する。該内面溝付伝熱管(B)3は、該内面溝付伝熱管(A)を拡管することによって、該アルミニウムフィン2に組み付けられたものであり、拡管後の内面溝付伝熱管である。該内面溝付伝熱管(B)3は、ヘアピン加工部4で、ヘアピン加工されて、U字形状に加工されており、複数の該アルミニウムフィン2に挿通されて組み付けられている。そして、複数の該内面溝付伝熱管(B)3が、該アルミニウムフィン2に挿通され、該内面溝付伝熱管(B)3の該ヘアピン加工部4と反対側が、Uベンド管5により、1の該内面溝付伝熱管(B)3の管端と、他の該内面溝付伝熱管(B)3の管端が繋がれている。このことにより、該蒸発器用のクロスフィンチューブ型熱交換器1に、炭酸ガス冷媒6の流路が形成される。   FIG. 1 is a schematic view of a form example of a cross fin tube type heat exchanger for an evaporator manufactured using the inner surface grooved heat transfer tube (A). In FIG. 1, a cross fin tube heat exchanger 1 for an evaporator includes an aluminum fin 2 and an internal grooved heat transfer tube (B) 3. The inner surface grooved heat transfer tube (B) 3 is assembled to the aluminum fin 2 by expanding the inner surface grooved heat transfer tube (A), and is an inner surface grooved heat transfer tube after the expansion. The inner surface grooved heat transfer tube (B) 3 is hairpin processed at a hairpin processing portion 4 and processed into a U shape, and is inserted and assembled into the plurality of aluminum fins 2. A plurality of the inner surface grooved heat transfer tubes (B) 3 are inserted through the aluminum fins 2, and the side opposite to the hairpin processed portion 4 of the inner surface grooved heat transfer tubes (B) 3 is formed by a U bend tube 5. The tube end of one inner surface grooved heat transfer tube (B) 3 is connected to the other end of the inner surface grooved heat transfer tube (B) 3. As a result, a flow path for the carbon dioxide refrigerant 6 is formed in the cross fin tube type heat exchanger 1 for the evaporator.

図2は、該内面溝付伝熱管(A)及び該内面溝付伝熱管(B)を、管軸方向に対して垂直な面で切ったときの断面図である。   FIG. 2 is a cross-sectional view of the inner-grooved heat transfer tube (A) and the inner-grooved heat transfer tube (B) taken along a plane perpendicular to the tube axis direction.

図2に示すように、内面溝付伝熱管10を管軸方向対して垂直な面で切った断面において、該内面溝付伝熱管10の管内面には、管周方向13に、多数の内面溝12が、管軸方向に対して、一定のらせん角θ(°)をもって、らせん状に形成されると共に、多数の内面フィン11が、らせん状に形成されている。管外径D(mm)とは、該内面溝付伝熱管10の外径を指す。なお、該内面溝付伝熱管10には、管周方向13に亘って該内面溝12及び該内面フィン11が形成されているが、作図の都合上、図2においては、該内面溝12及び該内面フィン11の一部を記載し、他の記載を省略した。   As shown in FIG. 2, in the cross section obtained by cutting the inner surface grooved heat transfer tube 10 along a plane perpendicular to the tube axis direction, the inner surface grooved heat transfer tube 10 has a plurality of inner surfaces in the tube circumferential direction 13. The groove 12 is formed in a spiral shape with a constant spiral angle θ (°) with respect to the tube axis direction, and a large number of inner surface fins 11 are formed in a spiral shape. The tube outer diameter D (mm) refers to the outer diameter of the internally grooved heat transfer tube 10. The inner surface grooved heat transfer tube 10 is formed with the inner surface grooves 12 and the inner surface fins 11 in the tube circumferential direction 13, but for the sake of drawing, in FIG. A part of the inner fin 11 is described, and other description is omitted.

図3及び図4は、該内面溝付伝熱管(A)及び該内面溝付伝熱管(B)の断面のうちの内面フィンの一部分を拡大した図である。   3 and 4 are enlarged views of a part of the inner fins in the cross section of the inner surface grooved heat transfer tube (A) and the inner surface grooved heat transfer tube (B).

図3に示すように、該内面溝付伝熱管10の管内面には、該内面溝12及び該内面フィン11が形成されている。該内面フィン11の形状は、管の中心に向かって細くなっている略等脚台形である。図3中、底肉厚t(mm)とは、該内面溝付伝熱管10の該内面溝12の最も深い部分22における該内面溝付伝熱管10の肉厚を指す。なお、以下、各内面溝12の最も深い部分22が円周上に重なるように引いた円、すなわち、該内面溝付伝熱管10の外周の円と同心円であり且つ半径が該底肉厚t分だけ小さい円を、底肉厚線23(図3中、符号23で示す一点鎖線)と呼ぶ。内面フィン高さh(mm)とは、該内面フィン11の頂点21の高さを指し、該底肉厚線23から管の中心に向かって突き出している部分の長さを指す。ここで、該内面フィン高さhは、該内面フィン11の幅方向の中央部の高さ、つまり、該内面フィンの中心線の長さである。内面フィンピッチp(mm)とは、隣り合う該内面フィン11間における、該内面フィン11の中心線と該底肉厚線23とが交差する点間の直線距離を指す。内面溝側面角α(°)は、該内面溝12の側面を延ばしたときの交差角を示す。なお、該内面溝付伝熱管10では、αが0°より大きいので、該内面溝12は、下に行くほど幅が狭くなる形状を有している。そして、図3において、αが0°のときは、内面溝の両側の側面同士は平行であり、0°より大きくなる(正の数)と、内面溝の形状は、下に行くほど(管の中心から外側に向かうほど)幅が狭くなる形状となる。一方、0°未満になる(負の数)と、内面溝の形状は、下に行くほど幅が広くなる形状となる。内面フィン幅Wf(mm)は、該内面フィン高さhの半分の位置における、該内面フィン11の幅を指す。なお、該内面フィン11の先端の形状は、図3及び図4では円弧であるが、これに限らず、先端が偏平となった形状や、先端が尖った三角形状であってもよい。   As shown in FIG. 3, the inner surface grooves 12 and the inner surface fins 11 are formed on the inner surface of the inner surface grooved heat transfer tube 10. The shape of the inner fin 11 is a substantially isosceles trapezoid that is narrowed toward the center of the tube. In FIG. 3, the bottom wall thickness t (mm) indicates the wall thickness of the inner surface grooved heat transfer tube 10 at the deepest portion 22 of the inner surface groove 12 of the inner surface grooved heat transfer tube 10. Hereinafter, a circle drawn so that the deepest portion 22 of each inner surface groove 12 overlaps on the circumference, that is, a circle that is concentric with the outer circumference circle of the inner surface grooved heat transfer tube 10 and the radius is the bottom wall thickness t. A circle that is smaller by the amount is called a bottom thick line 23 (a chain line indicated by reference numeral 23 in FIG. 3). The inner fin height h (mm) refers to the height of the apex 21 of the inner fin 11 and refers to the length of the portion protruding from the bottom wall thickness line 23 toward the center of the tube. Here, the inner fin height h is the height of the central portion of the inner fin 11 in the width direction, that is, the length of the center line of the inner fin. The inner surface fin pitch p (mm) refers to the linear distance between the adjacent inner surface fins 11 between the points where the center line of the inner surface fins 11 and the bottom wall thickness line 23 intersect. The inner groove side surface angle α (°) indicates a crossing angle when the side surface of the inner surface groove 12 is extended. In the inner surface grooved heat transfer tube 10, since α is larger than 0 °, the inner surface groove 12 has a shape whose width becomes narrower toward the bottom. In FIG. 3, when α is 0 °, the side surfaces on both sides of the inner surface groove are parallel to each other, and when the angle is larger than 0 ° (positive number), the shape of the inner surface groove decreases toward the bottom (tube The width becomes narrower toward the outside from the center. On the other hand, when the angle is less than 0 ° (negative number), the shape of the inner surface groove becomes a shape that becomes wider as it goes downward. The inner fin width Wf (mm) refers to the width of the inner fin 11 at a position half the inner fin height h. The shape of the tip of the inner fin 11 is an arc in FIGS. 3 and 4, but is not limited thereto, and may be a shape with a flat tip or a triangular shape with a sharp tip.

図4中、内面溝深さd(mm)とは、内面フィン頂点線24から、該内面溝12の最も深い部分22までの距離である。なお、該内面溝付伝熱管10の該内面フィン11の頂点21が円周上に重なるように引いた円、すなわち、該内面溝付伝熱管10の外周の円と同心円であり且つ半径が該底肉厚t及び該内面フィン高さhの合計分だけ小さい円を、該内面フィン頂点線24(図4中、符号24で示す一点鎖線)と呼ぶ。内面溝幅Wg(mm)は、該内面溝深さdの半分の位置における、該内面溝12の幅を指す。   In FIG. 4, the inner surface groove depth d (mm) is a distance from the inner surface fin apex line 24 to the deepest portion 22 of the inner surface groove 12. Note that a circle drawn so that the apex 21 of the inner surface fin 11 of the inner surface grooved heat transfer tube 10 overlaps the circumference, that is, a circle that is concentric with an outer periphery circle of the inner surface grooved heat transfer tube 10 and has a radius A circle that is smaller by the sum of the bottom wall thickness t and the inner fin height h is called the inner fin apex line 24 (a chain line indicated by reference numeral 24 in FIG. 4). The inner surface groove width Wg (mm) indicates the width of the inner surface groove 12 at a position half the inner surface groove depth d.

該内面溝付伝熱管(A)は、拡管率3〜9%で拡管されて、該アルミニウムフィンに固着されて取り付けられる。そして、該内面溝付伝熱管(A)が、下記式(2)、(3)及び(4):
0.07≦Wg≦0.15 (2)
0.5≦Wg/d≦0.8 (3)
0<α≦15 (4)
の全てを満たす内面溝を有することにより、拡管率3〜9%で拡管した内面溝付伝熱管、すなわち、内面溝付伝熱管(B)に、核沸騰を促進させる効果が高い内面溝を形成させることができる。
The inner surface grooved heat transfer tube (A) is expanded at a tube expansion rate of 3 to 9%, and is fixedly attached to the aluminum fin. And this inner surface grooved heat exchanger tube (A) is the following formulas (2), (3) and (4):
0.07 ≦ Wg ≦ 0.15 (2)
0.5 ≦ Wg / d ≦ 0.8 (3)
0 <α ≦ 15 (4)
By having an inner groove satisfying all of the above, an inner groove having a high effect of promoting nucleate boiling is formed in the inner groove groove heat transfer tube expanded at a tube expansion rate of 3 to 9%, that is, the inner groove groove heat transfer tube (B). Can be made.

上記式(2)、(3)及び(4)の全てを満たす内面溝は、拡管率3〜9%で拡管されたときに、内面溝幅が狭く且つ内面溝幅に対して内面溝深さが深い内面溝となる。そして、このような内面溝は、オープンキャビティーとして機能して、核沸騰を促進させるので、蒸発熱伝達率を高くすることができる。すなわち、液冷媒は内面溝内で気相となって核沸騰の起点となるが、内面溝幅が狭く且つ内面溝幅に対して内面溝深さが深い内面溝は、この気相を内面溝内で保持する機能が高く、核沸騰を持続させることができるので、核沸騰を促進させる効果が高い。特に、熱交換器の冷媒入口付近の液膜が厚い低クォリティー領域において、その効果が顕著なものとなる。そのため、上記式(2)、(3)及び(4)の全てを満たす内面溝を有する内面溝付伝熱管(A)は、拡管率3〜9%で拡管して得られる該内面溝付伝熱管(B)に、内面溝内で発生した核沸騰の起点となる気相を、内面溝内で保持する機能が高い内面溝、つまり、内面溝幅が狭く且つ内面溝幅に対して内面溝深さが深い内面溝を形成させることができる。   When the inner surface groove satisfying all the above formulas (2), (3) and (4) is expanded at a tube expansion rate of 3 to 9%, the inner surface groove width is narrower and the inner surface groove depth is smaller than the inner surface groove width. Becomes a deep inner groove. Such an inner surface groove functions as an open cavity and promotes nucleate boiling, so that the evaporation heat transfer coefficient can be increased. That is, the liquid refrigerant becomes a gas phase in the inner surface groove and becomes a starting point of nucleate boiling. However, the inner surface groove having a narrow inner surface groove width and a deep inner surface groove depth with respect to the inner surface groove width has the gas phase separated into the inner surface groove. Since the function to hold in the inside is high and nucleate boiling can be maintained, the effect of promoting nucleate boiling is high. In particular, the effect becomes remarkable in the low quality region where the liquid film near the refrigerant inlet of the heat exchanger is thick. Therefore, the inner surface grooved heat transfer tube (A) having the inner surface groove satisfying all of the above formulas (2), (3) and (4) is obtained by expanding the inner surface grooved tube at a tube expansion rate of 3 to 9%. In the heat pipe (B), an inner surface groove having a high function of holding the gas phase that is the starting point of nucleate boiling generated in the inner surface groove in the inner surface groove, that is, the inner surface groove width is narrow and the inner surface groove width is smaller than the inner surface groove width A deep inner groove can be formed.

該内面溝付伝熱管(A)のWg、Wg/d及びαの範囲を、上記範囲とする必要があるのは、後述する拡管後の内面溝付伝熱管(B)のWg’、Wg’/d’及びα’を、後述する範囲とするためである。すなわち、Wgが0.15を超えるか、Wg/dが0.8を超えるか、又はαが15を超えると、拡管後の内面溝付伝熱管(B)の内面溝内に沸騰の起点となる気相を十分に保持することができないので、核沸騰を促進させるという効果が得られない。また、Wgが0.07未満だと、拡管後の内面溝付伝熱管(B)の溝幅が狭くなり過ぎて、対流による熱伝達促進が不十分となる。また、Wg/dが0.5未満だと、拡管後の内面溝付伝熱管(B)の内面溝内に液冷媒が入り込み難くなり、熱伝達が促進されない。また、αが0以下だと、内面溝付伝熱管(A)の製造が難しくなる。   The reason why the range of Wg, Wg / d and α of the inner surface grooved heat transfer tube (A) needs to be within the above range is that Wg ′ and Wg ′ of the inner surface grooved heat transfer tube (B) after tube expansion described later. This is because / d ′ and α ′ are within the ranges described later. That is, when Wg exceeds 0.15, Wg / d exceeds 0.8, or α exceeds 15, the origin of boiling in the inner surface groove of the inner surface grooved heat transfer tube (B) after tube expansion Therefore, the effect of promoting nucleate boiling cannot be obtained. On the other hand, if Wg is less than 0.07, the groove width of the inner surface grooved heat transfer tube (B) after the tube expansion becomes too narrow, and the heat transfer promotion by convection becomes insufficient. On the other hand, if Wg / d is less than 0.5, it becomes difficult for the liquid refrigerant to enter the inner groove of the heat-transfer tube with inner groove (B) after the expansion, and heat transfer is not promoted. Moreover, when (alpha) is 0 or less, manufacture of an internally grooved heat exchanger tube (A) will become difficult.

なお、該内面溝付伝熱管(A)において、管軸方向に垂直な断面における管周方向の全内面溝のうちの一部に、前記式(2)、(3)及び(4)の全てを満たす内面溝があれば、拡管後に核沸騰の促進に十分寄与する。そして、管軸方向に垂直な断面における管周方向の全内面溝のうちの50%以上が、前記式(2)、(3)及び(4)の全てを満たす内面溝であることが好ましく、管軸方向に垂直な断面における管周方向の全内面溝の全てが、前記式(2)、(3)及び(4)の全てを満たす内面溝であることが特に好ましい。   In the inner surface grooved heat transfer tube (A), all of the above formulas (2), (3), and (4) may be formed on a part of all the inner surface grooves in the tube circumferential direction in the cross section perpendicular to the tube axis direction. If there is an inner groove satisfying the condition, it will contribute to the promotion of nucleate boiling after expansion. And it is preferable that 50% or more of all the inner surface grooves in the tube circumferential direction in the cross section perpendicular to the tube axis direction are inner surface grooves satisfying all of the above formulas (2), (3) and (4), It is particularly preferable that all the inner surface grooves in the pipe circumferential direction in the cross section perpendicular to the tube axis direction are inner surface grooves that satisfy all the expressions (2), (3), and (4).

該内面溝付伝熱管(A)では、下記式(1):
0.06≦t/D≦0.095 (1)
を満たす。該内面溝付伝熱管(A)におけるt/Dの値を上記範囲とする必要があるのは、後述する拡管後の内面溝付伝熱管(B)におけるt’/D’の値を、0.055≦t’/D’≦0.09とするためである。
In the internally grooved heat transfer tube (A), the following formula (1):
0.06 ≦ t / D ≦ 0.095 (1)
Meet. The reason why the value of t / D in the inner surface grooved heat transfer tube (A) needs to be in the above range is that the value of t ′ / D ′ in the inner surface grooved heat transfer tube (B) after tube expansion described later is 0 This is because 0.055 ≦ t ′ / D ′ ≦ 0.09.

該内面溝付伝熱管(A)において、Dは4.0〜12.7であり、hは0.1〜0.3、好ましくは0.15〜0.20であり、dは0.08〜0.3、好ましくは0.15〜0.20であり、pは0.2〜0.5、好ましくは0.2〜0.25であり、Wfは0.08〜0.3、好ましくは0.1〜0.15である。   In the internally grooved heat transfer tube (A), D is 4.0 to 12.7, h is 0.1 to 0.3, preferably 0.15 to 0.20, and d is 0.08. -0.3, preferably 0.15-0.20, p is 0.2-0.5, preferably 0.2-0.25, and Wf is 0.08-0.3, preferably Is 0.1 to 0.15.

該内面溝付伝熱管(A)のらせん角θは、5°以上、好ましくは10〜30°である。らせん角が大きくなる程、液冷媒を伝熱管の頂部に上げる効果が大きくなり、管内面全体として液膜が薄くなる。液膜が薄くなる程、蒸発熱伝熱は促進され、蒸発熱伝達性能が向上する。なお、該らせん角θとは、該内面溝の管軸に対する角度を指す。   The helical groove θ of the inner surface grooved heat transfer tube (A) is 5 ° or more, preferably 10 to 30 °. The greater the helix angle, the greater the effect of raising the liquid refrigerant to the top of the heat transfer tube and the thinner the liquid film on the entire inner surface of the tube. As the liquid film becomes thinner, the evaporation heat transfer is promoted and the evaporation heat transfer performance is improved. The helical angle θ refers to the angle of the inner groove with respect to the tube axis.

該内面溝付伝熱管(A)の内面溝の乗数は、60〜100条/周、好ましくは75〜90条/周である。   The multiplier of the inner surface groove of the inner surface grooved heat transfer tube (A) is 60 to 100 strips / circumference, preferably 75 to 90 strips / circumference.

該内面溝付伝熱管(A)は、原管を転造加工することにより、該原管の内面に内面溝を形成することにより得られる。   The inner surface grooved heat transfer tube (A) is obtained by forming inner surface grooves on the inner surface of the original tube by rolling the original tube.

該原管の材質は、特に制限されるものではないが、加工性及び熱伝導性が共に良好な、純銅又は純銅に最大2%程度の添加成分を添加した低合金銅が好ましい。   The material of the original pipe is not particularly limited, but is preferably pure copper or low-alloy copper obtained by adding an additive component of up to about 2% to pure copper, which has good workability and thermal conductivity.

該原管を転造加工する方法としては、特に制限されない。例えば、公知の転造加工方法により、連続する1本の該原管の内側に、溝付きプラグを挿入し、該溝付きプラグと、該原管の外側に配置される円形ダイスとの間で、該原管を押圧することによって、該原管の管外径を縮径するとともに、管内面に溝を形成させて、該内面溝付伝熱管(A)を得る。   A method for rolling the raw pipe is not particularly limited. For example, a grooved plug is inserted into the inside of one continuous original pipe by a known rolling process method, and the grooved plug and a circular die disposed outside the original pipe are inserted. By pressing the original tube, the outer diameter of the original tube is reduced, and a groove is formed on the inner surface of the tube to obtain the inner surface grooved heat transfer tube (A).

該原管を転造加工したものの外径を縮径させて、該内面溝付伝熱管(A)を得る。   The inner diameter grooved heat transfer tube (A) is obtained by reducing the outer diameter of the rolled raw tube.

該内面溝付伝熱管(A)は、該アルミニウムフィンに挿通され、拡管されることにより、該アルミニウムフィンに固着されて、該アルミニウムフィンに組み付けられ、本発明の蒸発器用のクロスフィンチューブ型熱交換器が製造される。   The inner surface grooved heat transfer tube (A) is inserted into the aluminum fin and expanded, thereby being fixed to the aluminum fin and assembled to the aluminum fin, and the cross fin tube type heat for the evaporator of the present invention. An exchanger is manufactured.

該内面溝付伝熱管(A)を拡管する方法は、特に制限されず、例えば、公知の機械拡管や液圧拡管により、該内面溝付伝熱管(A)を拡管する方法が挙げられる。   The method for expanding the inner surface grooved heat transfer tube (A) is not particularly limited, and examples thereof include a method for expanding the inner surface grooved heat transfer tube (A) by a known mechanical tube expansion or hydraulic expansion tube.

該内面溝付伝熱管(A)を拡管する際の拡管条件は、伝熱管外径基準の拡大率(拡管率)で、3〜9%である。   The expansion condition when expanding the inner surface grooved heat transfer tube (A) is 3 to 9% in terms of the expansion rate (expansion rate) based on the outer diameter of the heat transfer tube.

そして、本発明の蒸発器用のクロスフィンチューブ型熱交換器は、該内面溝付伝熱管(A)を、アルミニウムフィンに挿通し、拡管率3〜9%で拡管することにより、該内面溝付伝熱管(A)を該アルミニウムフィンに固着して得られる蒸発器用のクロスフィンチューブ型熱交換器である。   And the cross fin tube type heat exchanger for evaporators of this invention inserts this inner surface grooved heat exchanger tube (A) into an aluminum fin, and expands this tube with a tube expansion ratio of 3 to 9%, thereby providing the inner surface grooved It is a cross fin tube type heat exchanger for an evaporator obtained by fixing the heat transfer tube (A) to the aluminum fin.

言い換えると、本発明の蒸発器用のクロスフィンチューブ型熱交換器は、アルミニウムフィンと、該アルミニウムフィンに組み付けられている内面溝付伝熱管(B)とを有し、二酸化炭素を主成分とする冷媒を用いる蒸発器用のクロスフィンチューブ型熱交換器であって、
該内面溝付伝熱管(B)の底肉厚をt’(mm)、管外径をD’(mm)とするとき、下記式(5):
0.055≦t’/D’≦0.09 (5)
を満たし、
該内面溝付伝熱管(B)の内面溝深さをd’(mm)、内面溝幅をWg’(mm)、内面溝側面角をα’(°)とするとき、該内面溝付伝熱管(B)が、下記式(6)、(7)及び(8):
0.06≦Wg’≦0.14 (6)
0.55≦Wg’/d’≦0.85 (7)
0<α’≦15 (8)
の全てを満たす内面溝を有する蒸発器用のクロスフィンチューブ型熱交換器である。
In other words, the cross fin tube type heat exchanger for an evaporator of the present invention has an aluminum fin and an internally grooved heat transfer tube (B) assembled to the aluminum fin, and mainly contains carbon dioxide. A cross-fin tube heat exchanger for an evaporator using a refrigerant,
When the bottom wall thickness of the inner surface grooved heat transfer tube (B) is t ′ (mm) and the tube outer diameter is D ′ (mm), the following formula (5):
0.055 ≦ t ′ / D ′ ≦ 0.09 (5)
The filling,
When the inner surface groove depth of the inner surface grooved heat transfer tube (B) is d ′ (mm), the inner surface groove width is Wg ′ (mm), and the inner surface groove side surface angle is α ′ (°), the inner surface grooved heat transfer tube (B). The heat pipe (B) has the following formulas (6), (7) and (8):
0.06 ≦ Wg ′ ≦ 0.14 (6)
0.55 ≦ Wg ′ / d ′ ≦ 0.85 (7)
0 <α ′ ≦ 15 (8)
This is a cross fin tube type heat exchanger for an evaporator having an inner surface groove that satisfies all of the above.

本発明の蒸発器用のクロスフィンチューブ型熱交換器に係る該アルミニウムフィンの材質は、特に制限されるものではないが、加工性及び熱伝導性が高い点で、JIS A 1050等の純アルミニウムが好ましい。   The material of the aluminum fin according to the cross fin tube type heat exchanger for an evaporator of the present invention is not particularly limited, but pure aluminum such as JIS A 1050 is used in terms of high workability and thermal conductivity. preferable.

本発明の蒸発器用のクロスフィンチューブ型熱交換器は、二酸化炭素を主成分とする冷媒を用いる蒸発器用として用いられる。本発明の蒸発器用のクロスフィンチューブ型熱交換器に用いられる該二酸化炭素を主成分とする冷媒は、二酸化炭素単独か、あるいは、冷凍機油を0〜15質量%含有する二酸化炭素冷媒である。   The cross fin tube type heat exchanger for an evaporator of the present invention is used for an evaporator using a refrigerant mainly composed of carbon dioxide. The refrigerant mainly composed of carbon dioxide used in the cross fin tube type heat exchanger for an evaporator of the present invention is carbon dioxide alone or a carbon dioxide refrigerant containing 0 to 15% by mass of refrigerating machine oil.

本発明の蒸発器用のクロスフィンチューブ型熱交換器には、該内面溝付伝熱管(B)、つまり、拡管後の内面溝付伝熱管が組み付けられている。   The cross-fin tube type heat exchanger for an evaporator of the present invention is assembled with the internally grooved heat transfer tube (B), that is, the internally grooved heat transfer tube after expansion.

該内面溝付伝熱管(B)は、該内面溝付伝熱管(A)が拡管率3〜9%で拡管されたものである。そして、本発明の蒸発器用のクロスフィンチューブ型熱交換器では、該内面溝付伝熱管(B)が、下記式(6)、(7)及び(8):
0.06≦Wg’≦0.14 (6)
0.55≦Wg’/d’≦0.85 (7)
0<α’≦15 (8)
の全てを満たす内面溝を有することにより、核沸騰を促進させる効果が高くなる。
The inner surface grooved heat transfer tube (B) is obtained by expanding the inner surface grooved heat transfer tube (A) at a tube expansion rate of 3 to 9%. And in the cross fin tube type heat exchanger for evaporators of this invention, this inner surface grooved heat exchanger tube (B) is following formula (6), (7) and (8):
0.06 ≦ Wg ′ ≦ 0.14 (6)
0.55 ≦ Wg ′ / d ′ ≦ 0.85 (7)
0 <α ′ ≦ 15 (8)
By having the inner groove satisfying all of the above, the effect of promoting nucleate boiling is enhanced.

上記式(6)、(7)及び(8)の全てを満たす内面溝は、内面溝幅が狭く且つ内面溝幅に対して内面溝深さが深い内面溝である。前述したように、このような内面溝は、オープンキャビティーとして機能して、核沸騰を促進させるので、蒸発熱伝達率を高くすることができる。すなわち、内面溝内で液冷媒が気相となって核沸騰の起点となるが、上記式(6)、(7)及び(8)の全てを満たす内面溝は、この気相を内面溝内で保持する機能が高く、核沸騰を持続させることができるので、核沸騰を促進させる効果が高い。特に、熱交換器の冷媒入口付近の液膜が厚い低クォリティー領域において、その効果が顕著なものとなる。   The inner surface groove that satisfies all of the above formulas (6), (7), and (8) is an inner surface groove that has a narrow inner surface groove width and a deep inner surface groove depth with respect to the inner surface groove width. As described above, such an inner surface groove functions as an open cavity and promotes nucleate boiling, so that the evaporation heat transfer coefficient can be increased. That is, the liquid refrigerant becomes a gas phase in the inner surface groove and becomes the starting point of nucleate boiling, but the inner surface groove satisfying all of the above formulas (6), (7) and (8) Since the function to hold in is high and nucleate boiling can be sustained, the effect of promoting nucleate boiling is high. In particular, the effect becomes remarkable in the low quality region where the liquid film near the refrigerant inlet of the heat exchanger is thick.

一方、Wg’が0.14を超えるか、Wg’/d’が0.85を超えるか、又はα’が15を超えると、核沸騰の起点となる気相を十分に保持することができないので、核沸騰を促進させるという効果が得られない。また、Wg’が0.06未満だと、溝幅が狭くなり過ぎて、対流による熱伝達促進が不十分となる。また、Wg’/d’が0.55未満だと、液冷媒が内面溝内に入り込み難くなり、熱伝達が促進されない。また、αが0以下だと、内面溝付伝熱管(A)の製造が難しくなる。   On the other hand, if Wg ′ exceeds 0.14, Wg ′ / d ′ exceeds 0.85, or α ′ exceeds 15, the gas phase that is the starting point of nucleate boiling cannot be sufficiently retained. Therefore, the effect of promoting nucleate boiling cannot be obtained. On the other hand, if Wg ′ is less than 0.06, the groove width becomes too narrow and heat transfer promotion by convection becomes insufficient. On the other hand, if Wg ′ / d ′ is less than 0.55, it becomes difficult for the liquid refrigerant to enter the inner surface groove, and heat transfer is not promoted. Moreover, when (alpha) is 0 or less, manufacture of an internally grooved heat exchanger tube (A) will become difficult.

なお、該内面溝付伝熱管(B)において、管軸方向に垂直な断面における管周方向の全内面溝のうちの一部に、前記式(6)、(7)及び(8)の全てを満たす内面溝があれば、核沸騰の促進に十分寄与する。そして、管軸方向に垂直な断面における管周方向の全内面溝のうちの50%以上が、前記式(6)、(7)及び(8)の全てを満たす内面溝であることが好ましく、管軸方向に垂直な断面における管周方向の全内面溝の全てが、前記式(6)、(7)及び(8)の全てを満たす内面溝であることが特に好ましい。   In the inner surface grooved heat transfer tube (B), all of the above formulas (6), (7), and (8) may be formed on a part of the entire inner surface groove in the tube circumferential direction in the cross section perpendicular to the tube axis direction. If there is an inner groove that satisfies the condition, it will contribute to the promotion of nucleate boiling. And it is preferable that 50% or more of all the inner surface grooves in the pipe circumferential direction in the cross section perpendicular to the tube axis direction are inner surface grooves satisfying all of the above formulas (6), (7) and (8), It is particularly preferable that all the inner surface grooves in the pipe circumferential direction in the cross section perpendicular to the tube axis direction are inner surface grooves that satisfy all of the expressions (6), (7), and (8).

該内面溝付伝熱管(B)において、0.055≦t’/D’≦0.09である。二酸化炭素を主成分とする冷媒は、その作動圧力が3.5〜15MPaと高いため、伝熱管の耐圧強度を向上させる必要があり、そのため、該底肉厚tを厚くする必要がある。該底肉厚tの厚さは、該管外径D及び伝熱管材質の引張強さσBにより、安全係数を考慮して適宜決定される。伝熱管材質として一般的に用いられるりん脱酸銅等の軟質材又は純銅に最大2質量%程度の添加成分を添加した低合金銅の場合、拡管後の該内面溝付伝熱管(B)では、t’/D’は、0.055以上であることが必要である。一方、t’/D’が0.09を超えると、該内面溝付伝熱管(B)の単重が大きくなって、コストアップとなるとともに、熱伝達性が悪くなり、該内面フィン高さhを低くせざるを得なくなることから、十分な熱交換性能が得られなくなる。そのため、t’/D’は0.09以下であることが必要である。   In the inner surface grooved heat transfer tube (B), 0.055 ≦ t ′ / D ′ ≦ 0.09. Since the refrigerant having carbon dioxide as a main component has a high operating pressure of 3.5 to 15 MPa, it is necessary to improve the pressure resistance of the heat transfer tube. Therefore, it is necessary to increase the bottom wall thickness t. The thickness of the bottom wall thickness t is appropriately determined in consideration of a safety factor by the outer diameter D of the tube and the tensile strength σB of the heat transfer tube material. In the case of a soft material such as phosphorus deoxidized copper generally used as a heat transfer tube material or low alloy copper in which an additive component of up to about 2% by mass is added to pure copper, the inner surface grooved heat transfer tube (B) after expansion is , T ′ / D ′ needs to be 0.055 or more. On the other hand, when t ′ / D ′ exceeds 0.09, the unit weight of the inner surface grooved heat transfer tube (B) increases, resulting in an increase in cost and heat transfer performance, and the inner fin height. Since h must be lowered, sufficient heat exchange performance cannot be obtained. Therefore, t ′ / D ′ needs to be 0.09 or less.

該内面溝付伝熱管(B)の内面フィン高さをh’(mm)、内面フィンピッチをp’(mm)、内面フィン幅をWf’(mm)とすると、該内面溝付伝熱管(B)において、D’は4.0〜12.7であり、h’は0.10〜0.3、好ましくは0.15〜0.2であり、d’は0.08〜0.3、好ましくは0.15〜0.2であり、p’は0.2〜0.5、好ましくは0.20〜0.25であり、Wf’は0.08〜0.3、好ましくは0.1〜0.15である。   When the inner fin height of the inner grooved heat transfer tube (B) is h ′ (mm), the inner fin pitch is p ′ (mm), and the inner fin width is Wf ′ (mm), the inner groove heat transfer tube ( In B), D ′ is 4.0 to 12.7, h ′ is 0.10 to 0.3, preferably 0.15 to 0.2, and d ′ is 0.08 to 0.3. , Preferably 0.15 to 0.2, p ′ is 0.2 to 0.5, preferably 0.20 to 0.25, and Wf ′ is 0.08 to 0.3, preferably 0. .1 to 0.15.

該内面溝付伝熱管(B)のらせん角θ’は、5°以上、好ましくは10〜30°である。らせん角が大きくなる程、液冷媒を伝熱管の頂部に上げる効果が大きくなり、管内面全体として液膜が薄くなる。液膜が薄くなる程、蒸発熱伝熱は促進され、蒸発熱伝達性能が向上する。なお、該らせん角θとは、該内面溝の管軸に対する角度を指す。   The helical angle θ ′ of the internally grooved heat transfer tube (B) is not less than 5 °, preferably 10 to 30 °. The greater the helix angle, the greater the effect of raising the liquid refrigerant to the top of the heat transfer tube and the thinner the liquid film on the entire inner surface of the tube. As the liquid film becomes thinner, the evaporation heat transfer is promoted and the evaporation heat transfer performance is improved. The helical angle θ refers to the angle of the inner groove with respect to the tube axis.

該内面溝付伝熱管(B)の内面溝の条数は、60〜100条/周、好ましくは75〜90条/周である。   The number of the inner surface grooves of the inner surface grooved heat transfer tube (B) is 60 to 100 lines / cycle, preferably 75 to 90 lines / cycle.

次に、実施例を挙げて本発明を更に具体的に説明するが、これは単に例示であって、本発明を制限するものではない。   EXAMPLES Next, although an Example is given and this invention is demonstrated more concretely, this is only an illustration and does not restrict | limit this invention.

(実施例1〜7、比較例1〜5)
<転造加工>
りん脱酸銅製の原管を用いて、転造加工し、管外径Dが7mmの内面溝付伝熱管(拡管前)を作製した。得られた該内面溝付伝熱管(拡管前)の寸法諸元を表2〜表4に示す。
<クロスフィンチューブ型熱交換器の製造>
上記で得た該内面溝付伝熱管(拡管前)を、下記条件で機械拡管により拡管して、アルミニウムフィンに組み付け、図5に示す評価用のクロスフィンチューブ型熱交換器を製造した。その諸元を表1に示す。
(拡管の条件)
外径φ6.09mmの拡管プラグを用いて機械拡管を行った。
(Examples 1-7, Comparative Examples 1-5)
<Rolling processing>
Using an original pipe made of phosphorous deoxidized copper, it was rolled to produce an internally grooved heat transfer pipe (before pipe expansion) with a pipe outer diameter D of 7 mm. Tables 2 to 4 show dimensional specifications of the obtained heat transfer tube with inner groove (before tube expansion).
<Manufacture of cross fin tube type heat exchanger>
The internally grooved heat transfer tube (before tube expansion) obtained above was expanded by mechanical tube expansion under the following conditions and assembled to aluminum fins to produce a cross fin tube heat exchanger for evaluation shown in FIG. The specifications are shown in Table 1.
(Conditions for tube expansion)
Mechanical pipe expansion was performed using a pipe expansion plug having an outer diameter of φ6.09 mm.

Figure 2012052704
Figure 2012052704

<内面溝付伝熱管(拡管後)の抜管>
上記のようにして製造した評価用のクロスフィンチューブ型熱交換器から、内面溝付伝熱管(拡管後)を抜管した。該内面溝付伝熱管(拡管後)の寸法諸元を表2〜表4に示す。
<Extraction of heat transfer tube with inner groove (after expansion)>
From the cross fin tube type heat exchanger for evaluation produced as described above, the heat transfer tube with an inner groove (after expansion) was extracted. Tables 2 to 4 show dimensional specifications of the internally grooved heat transfer tube (after tube expansion).

<内面溝付伝熱管(拡管後)の管内熱伝達率性能評価>
図6に示すように、実施例1〜7及び比較例1〜5の評価用のクロスフィンチューブ型熱交換器より抜管した内面溝付伝熱管(拡管後)33を内管として、外管31の内側に挿通し、下記に示す条件に制御した二酸化炭素冷媒を拡管後の内面溝付伝熱管33内に流し、環状部32を流れる水と熱交換させ、水及び冷媒の出入口温度及び流量から熱伝達率を求めた。条件としては、伝熱管出口圧力4.07MPa、飽和温度:7.0℃、出口過熱度:3.0℃、入口乾き度0.1、質量冷媒速度:300又は500kg/m・sとした。その結果を表2〜表4に示す。
<In-pipe heat transfer coefficient performance evaluation of internally grooved heat transfer tube (after tube expansion)>
As shown in FIG. 6, an outer tube 31 with an inner-grooved heat transfer tube (after tube expansion) 33 extracted from the cross-fin tube type heat exchanger for evaluation of Examples 1 to 7 and Comparative Examples 1 to 5 as an inner tube. The carbon dioxide refrigerant controlled under the conditions shown below is passed through the inner surface of the heat exchanger tube 33 and the heat is exchanged with the water flowing through the annular portion 32, and the water and refrigerant inlet / outlet temperatures and flow rates are calculated. The heat transfer rate was determined. As conditions, the heat transfer tube outlet pressure was 4.07 MPa, the saturation temperature was 7.0 ° C., the outlet superheat degree was 3.0 ° C., the inlet dryness was 0.1, and the mass refrigerant speed was 300 or 500 kg / m 2 · s. . The results are shown in Tables 2-4.

Figure 2012052704
1)比較例1の内面溝付伝熱管(拡管後)の熱伝達率を100としたときの、各内面溝付伝熱管(拡管後)の熱伝達率
Figure 2012052704
1) Heat transfer coefficient of each internally grooved heat transfer tube (after tube expansion) when the heat transfer coefficient of the internally grooved heat transfer tube (after tube expansion) of Comparative Example 1 is 100

Figure 2012052704
1)比較例1の内面溝付伝熱管(拡管後)の熱伝達率を100としたときの、各内面溝付伝熱管(拡管後)の熱伝達率
Figure 2012052704
1) Heat transfer coefficient of each internally grooved heat transfer tube (after tube expansion) when the heat transfer coefficient of the internally grooved heat transfer tube (after tube expansion) of Comparative Example 1 is 100

Figure 2012052704
1)比較例1の内面溝付伝熱管(拡管後)の熱伝達率を100としたときの、各内面溝付伝熱管(拡管後)の熱伝達率
Figure 2012052704
1) Heat transfer coefficient of each internally grooved heat transfer tube (after tube expansion) when the heat transfer coefficient of the internally grooved heat transfer tube (after tube expansion) of Comparative Example 1 is 100

本発明によれば、熱交換性能に優れる蒸発器を製造することができる。   According to the present invention, an evaporator having excellent heat exchange performance can be manufactured.

1 蒸発器用のクロスフィンチューブ型交換器
2 アルミニウムフィン
3、10 内面溝付伝熱管
4 ヘアピン加工部
5 Uベンド管
11 内面フィン
12 内面溝
13 管周方向
21 内面フィンの頂点
22 内面溝12の最も深い部分
23 底肉厚線
24 内面フィン頂点線
31 外管
32 環状部
33 抜管した内面溝付伝熱管(拡管後)
D 管外径
t 底肉厚
d 内面溝深さ
h 内面フィン高さ
p 内面フィンピッチ
Wf 内面フィン幅
Wg 内面溝幅
α 内面溝側面角
DESCRIPTION OF SYMBOLS 1 Cross fin tube type exchanger 2 for evaporators Aluminum fin 3, 10 Heat-transfer tube 4 with inner surface groove Hairpin processing part 5 U bend tube 11 Inner surface fin 12 Inner surface groove 13 Pipe circumferential direction 21 Top of inner surface fin 22 Most of inner surface groove 12 Deep portion 23 Bottom wall thickness wire 24 Inner fin vertex line 31 Outer tube 32 Annular portion 33 Extruded inner surface grooved heat transfer tube (after tube expansion)
D Tube outer diameter t Bottom wall thickness d Inner groove depth h Inner fin height p Inner fin pitch Wf Inner fin width Wg Inner groove width α Inner groove side angle

Claims (2)

アルミニウムフィンと、該アルミニウムフィンに組み付けられている内面溝付伝熱管とを有し、二酸化炭素を主成分とする冷媒を用いる蒸発器用のクロスフィンチューブ型熱交換器用の内面溝付伝熱管であって、
該内面溝付伝熱管の底肉厚をt(mm)、管外径をD(mm)とするとき、下記式(1):
0.06≦t/D≦0.095 (1)
を満たし、
内面溝深さをd(mm)、内面溝幅をWg(mm)、内面溝側面角をα(°)とするとき、下記式(2)、(3)及び(4):
0.07≦Wg≦0.15 (2)
0.5≦Wg/d≦0.8 (3)
0<α≦15 (4)
の全てを満たす内面溝を有すること、
を特徴とする内面溝付伝熱管。
An internally grooved heat transfer tube for a cross fin tube type heat exchanger for an evaporator having an aluminum fin and an internally grooved heat transfer tube assembled to the aluminum fin and using a refrigerant mainly composed of carbon dioxide. And
When the bottom wall thickness of the internally grooved heat transfer tube is t (mm) and the tube outer diameter is D (mm), the following formula (1):
0.06 ≦ t / D ≦ 0.095 (1)
The filling,
When the inner surface groove depth is d (mm), the inner surface groove width is Wg (mm), and the inner surface groove side surface angle is α (°), the following formulas (2), (3) and (4):
0.07 ≦ Wg ≦ 0.15 (2)
0.5 ≦ Wg / d ≦ 0.8 (3)
0 <α ≦ 15 (4)
Having an internal groove that satisfies all of
An internally grooved heat transfer tube.
請求項1記載の内面溝付伝熱管を、アルミニウムフィンに挿通し、次いで、拡管率3〜9%で拡管することにより、該内面溝付伝熱管を該アルミニウムフィンに固着して得られることを特徴とする蒸発器用のクロスフィンチューブ型熱交換器。   The inner surface grooved heat transfer tube according to claim 1 is obtained by inserting the inner surface grooved heat transfer tube to the aluminum fin by inserting the inner surface grooved heat transfer tube into the aluminum fin and then expanding the tube at a tube expansion ratio of 3 to 9%. A cross-fin tube heat exchanger for the evaporator.
JP2010193697A 2010-08-31 2010-08-31 Heat transfer tube with grooved inner surface and cross fin tube type heat exchanger for evaporator Pending JP2012052704A (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002090086A (en) * 2000-09-20 2002-03-27 Sumitomo Light Metal Ind Ltd Inner helically grooved heat exchanger tube and method for manufacturing heat exchanger
JP2010019489A (en) * 2008-07-10 2010-01-28 Sumitomo Light Metal Ind Ltd Heat transfer pipe with inner helical groove for evaporator

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002090086A (en) * 2000-09-20 2002-03-27 Sumitomo Light Metal Ind Ltd Inner helically grooved heat exchanger tube and method for manufacturing heat exchanger
JP2010019489A (en) * 2008-07-10 2010-01-28 Sumitomo Light Metal Ind Ltd Heat transfer pipe with inner helical groove for evaporator

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