JP3918284B2

JP3918284B2 - Cross fin tube heat exchanger

Info

Publication number: JP3918284B2
Application number: JP06414698A
Authority: JP
Inventors: 昌昭北澤; 幸正矢野; 順一郎田中
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 1998-02-26
Filing date: 1998-02-26
Publication date: 2007-05-23
Anticipated expiration: 2018-02-26
Also published as: JPH11248385A

Description

【０００１】
【発明の属する技術分野】
この発明は、例えばセパレート形空気調和機の室外機に内装されるクロスフィンチューブ型熱交換器に関するものである。
【０００２】
【従来の技術】
従来のクロスフィンチューブ型熱交換器は、図５（ａ）に示すように、薄板状の多数のフィン３１と、これらフィン３１を水平に貫通する直管状の複数の伝熱管３２・３３とを設けて構成されている。これら伝熱管３２・３３は、紙面手前側と奥側との２つの垂直面に沿って、それぞれ、冷媒が蛇行しながら上下方向に流通するように、所定の間隔で並設されると共に左右両端が交互に接続されている。
【０００３】
すなわち、各伝熱管３２・３３は、下段側から２本ずつが、図において右端側でＵ字状曲管部３４によって相互に接続されたヘアピン形伝熱管にて構成され、また、図において左端側は、同図（ｂ）にも示す冷媒出入口管３２ａ・３３ａが最下段の伝熱管３２・３３にそれぞれ接続され、その上方二本づつが、列内連絡管３２ｂ・３３ｂによって相互に接続されている。そして、上端部に、各列の最上段の伝熱管３２・３３の端部同士を相互に接続する端部連絡管３５が設けられている。
【０００４】
この熱交換器３０を外気が同図（ｂ）中に付記しているような方向で通過するとき、例えば図中実線矢印で示すように、風上側の冷媒出入口管３２ａを通して冷媒を流入させると、この冷媒は風上側の伝熱管列３２…を下側から順次通過し、次いで、風下側の伝熱管列３３…を上段側から順次通過して風下側の冷媒出入口管３３ａを通して流出する。すなわち、同図（ｂ）中に示す側面視で逆Ｕ字状に、風上側から風下側に冷媒が流通する。
【０００５】
このような熱交換器３０をセパレート形空気調和機における室外熱交換器として用い、これと、図示しない圧縮機、四路切換弁、室内熱交換器、膨張機構とによって冷媒循環回路を構成する場合、上記熱交換器３０が凝縮器として機能する冷房運転時には、この熱交換器３０に風下側から風上側に冷媒を流通させ、また、蒸発器として機能する暖房運転時には、上記とは逆に、風上側から風下側に冷媒を流通させることで、いずれの場合にもより良好な熱交換効率を得ることができる。したがって、上記の熱交換器３０は、風上側の冷媒出入口管３２ａが膨張機構を介して室内熱交換器に、また、風下側の冷媒出入口管３３ａが四路切換弁を介して圧縮機にそれぞれ接続される。これにより、暖房運転時には、同図（ｂ）中実線矢印で示すように風上側から風下側に冷媒が流通し、また、四路切換弁を切換えて行う冷房運転時には、図中破線矢印で示すように風上側から風下側に冷媒が流通する。
【０００６】
一方、図６に示すクロスフィンチューブ型の熱交換器４０は、風上側と風下側との各列の最上段に冷媒出入口管３２ａ・３３ａが設けられ、各列の最下段同士を端部連絡管３５で相互に接続して構成されている。この場合、側面視でＵ字状に冷媒が流通することになるが、この構成の熱交換器４０も、暖房運転時に、図中実線矢印で示すように風上側から風下側に冷媒を流通させ、また、冷房運転時に、図中破線矢印で示すように風下側から風上側に冷媒を流通させるように冷媒回路中に介装される。
【０００７】
ところで、冬期などの外気温が低いときの暖房運転では、室外熱交換器の表面に着霜が生じ、したがって、適宜、暖房運転を中断して除霜運転が行われる。これを逆サイクルデフロスト方式、すなわち、室内ファンを停止した状態で、四路切換弁の切換操作により、圧縮機から吐出する高温冷媒を室外熱交換器に供給して除霜する方式では、図５（ｂ）および図６にそれぞれ破線矢印で示すように、冷房運転時と同様の流通方向で、冷媒がこれら熱交換器３０・４０を風下側から風上側に流通して除霜が行われることになる。
【０００８】
【発明が解決しようとする課題】
しかしながら、図５に示した逆Ｕ字タイプ、若しくは図６に示したＵ字タイプのように、除霜時に風下側から風上側に冷媒が流れるようにしたパス取り形状であると、除霜が効率的に行われ難く、この結果、充分な暖房能力が得られないという問題を生じている。
【０００９】
つまり、暖房運転中の着霜は、熱交換器における風下側よりも風上側に多く発生し、また、冷媒の出口側に多く発生する。したがって、除霜運転時の冷媒流通が風下側から風上側に流れる場合には、暖房運転時に冷媒の出口側であった領域をまず冷媒が通過することでこの領域の霜は溶かされるものの、風上側には、その後の圧力損失に応じて凝縮温度が低下した冷媒が流通することになる。このため、この着霜量の多い風上側を除霜するのに時間がかかり、或いは霜の溶け残りが生じるものとなって、暖房能力の低下を招来する。
【００１０】
この発明は、上記した問題点に鑑みなされたもので、その目的は、除霜時間をより短縮することが可能であり、これによって暖房能力を向上し得るクロスフィンチューブ型熱交換器を提供することにある。
【００１１】
【課題を解決するための手段】
そこで請求項１のクロスフィンチューブ型熱交換器は、冷媒が蛇行しながら上下方向に流通するように上下に所定の間隔で並設した複数の伝熱管３〜６の両端を交互に接続して形成した伝熱管列を風上側と風下側とにそれぞれ配置し、風上側伝熱管列と風下側伝熱管列との各上端の伝熱管３・５の端部同士を端部連絡管１０で相互に接続して成るクロスフィンチューブ型熱交換器であって、風上側伝熱管列と風下側伝熱管列とをそれぞれ上部伝熱管列と下部伝熱管列とに分割すると共に、風上側の上部伝熱管列下端の伝熱管３と風下側の下部伝熱管列上端の伝熱管６との各端部同士を相互に接続する第１中間部連絡管１１と、風上側の下部伝熱管列上端の伝熱管４と風下側の上部伝熱管列下端の伝熱管６との各端部同士を相互に接続する第２中間部連絡管１２とを設け、風上側伝熱管列と風下側伝熱管列との各下端の各伝熱管４・６に風上側冷媒出入口管８と風下側冷媒出入口管９とを接続し、蒸発器として機能させる運転時に冷媒が風上側冷媒出入口管８を通して流入し、風上側下部伝熱管列、風下側上部伝熱管列、風上側上部伝熱管列、風下側下部伝熱管列を順次通過して風下側冷媒出入口管９から流出し、除霜運転時には上記とは逆の流れとなるべく構成されていることを特徴としている。
【００１２】
この熱交換器においては、暖房運転時に冷媒を風上側の下部伝熱管列下端の伝熱管４に流入させることで、冷媒は、この風上側下部伝熱管列の各伝熱管４を通過した後、風下側上部伝熱管列・風上側上部伝熱管列・風下側下部伝熱管列を順次通過し、側面視で逆γ字状に流通する。
【００１３】
そして、除霜運転時に冷媒の流通方向が上記とは逆になると、冷媒は、まず、風下側下部伝熱管列、すなわち、暖房運転時における冷媒の出口側を通過し、次いで、風上側上部伝熱管列を流通することになる。したがって、特に、圧力損失に伴う冷媒温度の低下が大きくなる前に、着霜量の多い風上側を流通することになって、この風上側上半部に付着した霜が溶かされる。さらに、霜が溶けて生じたドレン水がその下方に流下するが、このドレン水によって、風上側下半部に付着した霜の除霜が促進される。この結果、全体的な除霜をより速やかに終了させることができ、その分、暖房運転時間の割合が増えるので、全体的な暖房能力が向上する。
【００１４】
請求項２のクロスフィンチューブ型熱交換器は、風上側の下部伝熱管列の下側に、風下側の下部伝熱管列に流入した冷媒が風上側に迂回して流通するように、風下側の下部伝熱管列下端側の伝熱管６に下部連絡管２５・２６で接続した氷結防止用伝熱管を設けていることを特徴としている。
【００１５】
この構成によれば、除霜運転時に風下側下部伝熱管列の下端側に流入させた冷媒は、風上側下部伝熱管列の下側に設けた氷結防止用伝熱管を一旦迂回した後に、前記逆γ字状に流通する。したがって、前述したように、風上側では、その上半部に付着した霜が溶かされ、さらに、霜が溶けて生じたドレン水によってその下半部の霜も溶かされて流下するが、このドレン水の量が多いと、熱交換器下端部でのドレン水の補水量が増加し、このドレン水が暖房運転時に氷結し易くなる。このため、次の除霜運転時の除霜時間が長くなる。そこで、除霜運転時に風下側に流入した冷媒を一旦風上側下端部に迂回させることで、上記のように氷結したドレン水もこれが速やかに溶かされて排出されることになり、したがって、これによっても、全体的な除霜時間が短縮される。
【００１６】
請求項３のクロスフィンチューブ型熱交換器は、冷媒が蛇行しながら上下方向に流通するように上下に所定の間隔で並設した複数の伝熱管３〜６の両端を交互に接続して形成した伝熱管列を風上側と風下側とにそれぞれ配置し、風上側伝熱管列と風下側伝熱管列との各下端の伝熱管４・６の端部同士を端部連絡管１０で相互に接続して成るクロスフィンチューブ型熱交換器であって、風上側伝熱管列と風下側伝熱管列とをそれぞれ上部伝熱管列と下部伝熱管列とに分割すると共に、風上側の上部伝熱管列下端の伝熱管３と風下側の下部伝熱管列上端の伝熱管６との各端部同士を相互に接続する第１中間部連絡管１１と、風上側の下部伝熱管列上端の伝熱管４と風下側の上部伝熱管列下端の伝熱管６との各端部同士を相互に接続する第２中間部連絡管１２とを設け、風上側伝熱管列と風下側伝熱管列との各上端の各伝熱管３・５に風上側冷媒出入口管８と風下側冷媒出入口管９とを接続し、蒸発器として機能させる運転時に冷媒が風上側冷媒出入口管８を通して流入し、風上側上部伝熱管列、風下側下部伝熱管列、風上側下部伝熱管列、風下側上部伝熱管列を順次通過して風下側冷媒出入口管９から流出し、除霜運転時には上記とは逆の流れとなるべく構成されていることを特徴としている。
【００１７】
この構成では、風上側伝熱管列と風下側伝熱管列との各下端の伝熱管４・６を相互に接続した構成であることから、暖房運転時に冷媒を風上側の上部伝熱管列上端の伝熱管に流入させることで、冷媒は、この風上側上部伝熱管列の各伝熱管を通過した後、風下側下部伝熱管列・風上側下部伝熱管列・風下側上部伝熱管列を順次通過し、側面視でγ字状に流通する。
【００１８】
そして、除霜運転時に冷媒の流通方向が上記とは逆になると、冷媒は、風下側上部伝熱管列を通過後に風上側下部伝熱管列を流通する。したがって、この場合にも、圧力損失に伴う冷媒温度の低下が大きくなる前に着霜量の多い風上側を冷媒が流通することになるので、前記した従来の逆Ｕ字状やＵ字状のパス取り形状の熱交換器に比べ、全体的な除霜時間を短縮することができる。
【００１９】
請求項４のクロスフィンチューブ型熱交換器は、請求項１〜３のいずれかの熱交換器の１種類又は複数種類を上下複数段設けていることを特徴としている。
【００２０】
この場合、各熱交換器に互いに並列に冷媒を流通させることで、前述した効率的な除霜を各熱交換器毎に得ることができる。これにより、熱交換能力が大きく、かつ、除霜性能の良好な大形の熱交換器を得ることができる。
【００２１】
請求項５のクロスフィンチューブ型熱交換器は、請求項４の熱交換器において、請求項２の熱交換器を最下段に配置したことを特徴としている。
【００２２】
すなわち、上下複数段として大形の熱交換器を構成する場合に、最下段に、氷結防止用伝熱管を下端側に備える熱交換器を配置する。これにより、前記同様に、ドレン水の量が多いときに熱交換器下端部で生じ易いドレン水の氷結も、これが速やかに溶かされ排出されることになる。したがって、ドレン水の量が多くなる大形の熱交換器でも、全体的な除霜時間を短縮することができる。
【００２３】
【発明の実施の形態】
次に、この発明の一実施形態について図面を参照しつつ詳細に説明する。
【００２４】
図１（ａ）に示すように、本実施形態に係る熱交換器１は、例えばアルミニウム等のように熱伝導が良好な金属からなる薄板状の多数のフィン２と、これらフィン２を水平に貫通する直管状の複数の伝熱管３〜６とを設けて構成されている。これら伝熱管３〜６は、紙面に平行な２つの垂直面に沿って、それぞれ、上下方向に所定の間隔で複数本、図の場合には８本ずつ設けられている。以下、紙面手前側の８本のうちの上半分の４本の伝熱管３を風上側上部伝熱管列、下半分の４本の伝熱管４を風上側下部伝熱管列、紙面奥側の８本のうちの上半分の４本の伝熱管５を風下側上部伝熱管列、下半分の４本の伝熱管６を風下側下部伝熱管列とそれぞれ称して説明する。
【００２５】
各伝熱管３〜６の図において右端側は、下段側から２本ずつが、Ｕ字状の曲管部７によって順次接続されている。なお、１つの曲管部７と、その上下両端から各々水平に延びる一対の伝熱管とは、直管をその中央で１８０°曲げ成形して得られるヘアピン形伝熱管にて一体的に形成されている。また、各伝熱管３〜６の図において左端側は、同図（ｂ）にも示すように、各伝熱管列毎に、下から２段目と３段目との伝熱管の端部同士が、それぞれ、Ｕ字状の列内連絡管３ａ〜６ａによって相互に接続されている。
【００２６】
そして、風上側と風下側との各下部伝熱管列における下端の伝熱管４・６に、風上側冷媒出入口管８、風下側冷媒出入口管９が各々接続される一方、風上側と風下側との各上部伝熱管列における各上端の伝熱管３・５の端部同士が、端部連絡管１０で相互に接続されている。さらに、風上側上部伝熱管列における下端の伝熱管３と風下側下部伝熱管列における上端の伝熱管６との各端部同士が第１中間部連絡管１１によって相互に接続され、また、風上側下部伝熱管列における上端の伝熱管４と風下側下部伝熱管列における下端の伝熱管５との各端部同士が第２中間部連絡管１２によって相互に接続されている。
【００２７】
上記構成の熱交換器１は、セパレート形空気調和機における室外機に、図示しない室外ファンに対面させて内装される。このとき、室外ファンの駆動に伴ってフィン２間を通過する外気が、図１（ｂ）において右から左に通過するものとすると、この熱交換器１は、これを蒸発器として機能させる暖房運転時に、冷媒が風上側冷媒出入口管８を通して流入し、風下側冷媒出入口管９を通して流出するように冷媒回路中に介装される。
【００２８】
このとき、風上側冷媒出入口管８を通して流入した冷媒は、図中実線矢印で示すように、まず、風上側下部伝熱管列の各伝熱管４を下側から順次通過した後、第２中間部連絡管１２を通して風下側上部伝熱管列下端の伝熱管５に流入する。したがって、次にはこの伝熱管列の各伝熱管５を順次通過することになる。その後、端部連絡管１０を通して風上側上部伝熱管列上端の伝熱管３に流入し、この伝熱管列の各伝熱管３を上側から順次通過した後、第１中間部連絡管１１を通して風下側下部伝熱管列上端の伝熱管６に送られ、この伝熱管列の各伝熱管６を順次通過した後に、風下側冷媒出入口管９を通して流出する。
【００２９】
このように、上記の熱交換器１は、図１（ｂ）に示す側面視で冷媒流れが略逆γ字状となるパス取り形状で形成されている。暖房運転時には、上記のような経路で冷媒がこの熱交換器１を流通する際に、フィン２間を通過する外気から吸熱して蒸発し、この熱エネルギーが室内熱交換器で室内に放熱される。
【００３０】
ところで、外気温度が低い状態で上記のような暖房運転を継続すると、熱交換器１に次第に着霜が生じ、これによって外気の流通が損なわれるようになって熱交換効率が低下する。そこで、適宜、除霜運転に切換えられるが、これを、室内機内における室内ファンを停止し、冷媒循環サイクルを上記とは逆にした逆サイクルデフロスト運転によって行う場合には、この熱交換器１を通過する冷媒の流れ方向は上記とは逆になる。すなわち、図１（ｂ）に破線矢印で示すように、まず、冷媒は風下側冷媒出入口管９を通して流入した後、風下側の下半部、風上側の上半部、風下側の上半部、風上側の下半部を順次通過して、風上側冷媒出入口管８を通して流出する。
【００３１】
このように、除霜運転時に冷媒流れが暖房運転時とは逆方向に生じる場合に、前記した逆γ字状のパス取り形状になっていることで、この除霜運転が効率的に行われる。すなわち、暖房運転の継続に伴う着霜は、風下側の面よりも風上側の面に多く生じ、また、冷媒の出口側で多く生じる。これに対し、除霜時における冷媒の流通が上記のように切換わると、冷媒は、まず、暖房運転時における冷媒の出口側、すなわち、風下側の下半部を通過し放熱して、この領域に生じた霜を溶かすことになる。そして、この領域での放熱に伴って凝縮した冷媒は、その後にこの熱交換器１を通過する際の圧力損失に伴って凝縮温度が次第に低下していくが、上記した風下側下半部の次には、風上側上半部に送られるので、この領域をより高温の温度状態の冷媒が流通することになる。
【００３２】
この結果、風上側上半部に生じた霜に、図２に示すように、この領域を流通する冷媒から充分な熱量が付与されてこれが速やかに溶かされ、ドレン水１３となってフィン２を伝って流下する。
【００３３】
一方、風上側下半部は、冷媒がこの領域での前記伝熱管４を最後に流通する領域となり、したがって、このときの冷媒は温度の低下を生じたものとなっているが、上記した風上側上半部からフィン２を伝ってドレン水１３が流下する際に、このドレン水１３からも、風上側下半部に生じている霜に熱量が付与される。これによって、この領域の除霜も速やかに生じさせることができる。この結果、熱交換器１の全体にわたり、短時間での除霜が可能となる。
【００３４】
なお、前記したように、暖房運転時には冷媒を風上側から風下側に流した方がより良好な熱交換効率が得られるが、上記熱交換器１では、各上部伝熱管列については風下側から風上側へと冷媒が流通することになって、上記関係が満たされず、この結果、暖房運転時の熱交換器効率は若干低下する。しかしながら、上記のように、除霜運転時間を短縮し得ることで暖房運転時間が長くなり、これによって、全体的な暖房性能を向上することができる。
【００３５】
図３には、この発明の他の実施形態におけるクロスフィンチューブ型熱交換器１を示している。この熱交換器１は、同図（ａ）に示すように、全体形状が平面視で略Ｌ字状に形成されている。そして、この熱交換器１は、同図（ｂ）に示すように、前記図１（ｂ）に示した熱交換器とほぼ同様に逆γ字のパス取り形状を各々採用した上下３段の熱交換器２１〜２３を設けて構成されている。なお、本実施形態では、フィン２は各熱交換器２１〜２３毎に上下に分離されてはおらず、上下方向の全体にわたって一体形状で形成されている。したがって、以下では、上段の熱交換器を第１熱交換部２１、中段の熱交換器を第２熱交換部２２、下段の熱交換器を第３熱交換部２３と称して説明する。
【００３６】
最上段の第１熱交換部２１には、その下端側の風上側と風下側とに各々冷媒出入口管８ａ・９ａが設けられ、上端側の端部連絡管１０と、中間高さ位置で相互に交差する第１中間部連絡管１１および第２中間部連絡管１２とによって、風上側と風下側との各伝熱管が相互に連結されている。同様に、中段の第２熱交換部２２にも、その下端側の風上側と風下側とに各々冷媒出入口管８ｂ・９ｂが設けられ、この第２熱交換器２２における上端側の端部連絡管１０と、中間高さ位置の第１・第２中間部連絡管１１・１２とによって、風上側と風下側との各伝熱管が相互に連結されている。また、下段の第３熱交換部２３も、その下端側の風上側と風下側とに各々冷媒出入口管８ｃ・９ｃが設けられ、この第３熱交換器２３における上端側の端部連絡管１０と、中間高さ位置の第１・第２中間部連絡管１１・１２とによって、風上側と風下側との各伝熱管が相互に連結されている。
【００３７】
そして、第１〜第３熱交換部２１〜２３の各風上側冷媒出入口管８ａ〜８ｃは、冷媒を分流または合流させるための図示しない風上側ヘッダにそれぞれ接続され、同様に、各風下側冷媒出入口管９ａ〜９ｃは風下側ヘッダにそれぞれ接続されている。したがって、例えば、風上側ヘッダを通して冷媒がこの熱交換器１に供給されると、同図中一点鎖線矢印で示すように、各熱交換部２１〜２３毎に、逆γ字のパス取り形状に応じた冷媒の流通が互いに並行に生じ、風下側ヘッダで合流して流出していくことになる。
【００３８】
なお、第３熱交換部２３の下端側には、同図（ａ）に示すように、風下側冷媒出入口管９ｃよりも下側にさらに１本の氷結防止用伝熱管２４が設けられている。この伝熱管２４の図において左端側は、風下側冷媒出入口管９ｃが接続された伝熱管６に曲管部７を介して接続されている。一方、風上側冷媒出入口管８ｃの下側には、図示してはいないが、左端側で相互に連結された２本の氷結防止用伝熱管がさらに設けられており、これら氷結防止用伝熱管のうちの下側の伝熱管の端部と、上記風下側の氷結防止用伝熱管２４の端部とが、同図（ｂ）に示す第１下部連絡管２５によって相互に接続されている。また、風上側の氷結防止用伝熱管のうちの上側の伝熱管の端部は、風下側冷媒出入口管９ｃの上段に位置する伝熱管の端部に、第２下部連絡管２６を介して接続されている。
【００３９】
このような構成により、後述する除霜運転時に、同図（ｂ）で一点鎖線矢印とは逆方向に、風下側冷媒出入口管９ｃを通して冷媒が流入すると、この冷媒は、風下側の氷結防止用伝熱管２４を通過後に第１下部連絡管２５を通して風上側に送られ、この風上側の２本の氷結防止用伝熱管を通過する。その後、第２下部連絡管２６を通して風下側に送られ、以降は、前記した逆γ字のパス取り形状に応じてこの第３熱交換部２３を流通し、風上側冷媒出入口管８ｃを通して流出することになる。
【００４０】
上記構成の熱交換器１は、図１を参照して説明した前記熱交換器と同様に、暖房運転時に、冷媒が図中一点鎖線矢印で示すように各熱交換部２１〜２３を通過した後に、各風下側冷媒出入口管９ａ〜９ｃを通して流出するように冷媒回路中に介装される。
【００４１】
そして、除霜運転時には、上記とは逆方向で冷媒が各熱交換部２１〜２３を流通することになり、これによって、各熱交換部２１〜２３毎に、冷媒が風下側下半部から風上側上半部へと流通する。したがって、前記同様に、着霜量の多い領域をより高温の冷媒が通過することで、特に風上側上半部の霜も速やかに溶かされ、また、風上側下半部の除霜も、その上半部から流下するドレン水で促進されることになって、全体にわたる除霜を短時間で完了させることができる。
【００４２】
なお、上記のように３段の熱交換部２１〜２３を設けて大形化した熱交換器１では全体的な着霜量が多くなる。これに伴い、フィン２を伝って流下するドレン水の量も多くなって、熱交換器下端部でのドレン水の補水量が増加し、このドレン水が暖房運転時に氷結し易くなる。そして、次の除霜運転時にこの氷結したドレン水を溶かして排出することが必要になって、除霜時間が長くなる。
【００４３】
このような場合に、上記熱交換器１では、前記したように、第３熱交換部２３の下端側に風下側冷媒出入口管９ｃを通して流入した高温の冷媒を一旦風上側に迂回させて前記した氷結防止用伝熱管を通して冷媒を流通させるようになっている。これにより、熱交換器１の下端側で氷結したドレン水も速やかに溶かされて排出されることになり、したがって、これによっても、全体的な除霜時間が短縮される。
【００４４】
図４には、この本発明のさらに他の実施形態におけるクロスフィンチューブ型熱交換器１を示している。この熱交換器１は、風上側冷媒出入口管８と風下側冷媒出入口管９とを、風上側と風下側との各上部伝熱管列の上端の各伝熱管に各々接続すると共に、端部連絡管１０を、各下部伝熱管列の下端の各伝熱管の端部同士の間に設けて、略γ字状のパス取り形状に構成されている。
【００４５】
この場合、実線矢印で示すように、暖房運転時に冷媒を風上側冷媒出入口管８を通して流入させることで、冷媒は、風上側上部伝熱管列の各伝熱管を通過した後、風下側下部伝熱管列・風上側下部伝熱管列・風下側上部伝熱管列を順次通過し、側面視でγ字状に流通する。
【００４６】
そして、除霜運転時に、図中破線矢印で示すように、冷媒の流通方向が上記とは逆になると、冷媒は、風下側上部伝熱管列を通過後に風上側下部伝熱管列を流通する。したがって、この場合にも、圧力損失に伴う冷媒温度の低下が大きくなる前に着霜量の多い風上側を冷媒が流通することになるので、前記した従来の逆Ｕ字状やＵ字状のパス取り形状を有する熱交換器に比べ、全体的な除霜時間を短縮することができる。
【００４７】
以上にこの発明の具体的な実施形態について説明したが、この発明は上記各形態に限定されるものではなく、この発明の範囲内で種々変更することができる。例えば、図３を参照して説明した実施形態では、それぞれ逆γ字状のパス取り形状を有する第１〜第３熱交換部２１〜２３を上下多段に設けた構成を例に挙げたが、図３における第３熱交換部２３のように下端部に氷結防止用伝熱管を備える熱交換器を上下多段に、また、図４を参照して説明したγ字状のパス取り形状を有する熱交換器を上下多段に設けた構成とすることも可能である。
【００４８】
さらに、例えば最上段を逆γ字状のパス取り形状の熱交換器、中段をγ字状のパス取り形状を有する熱交換器、最下段を、下端部に氷結防止用伝熱管を備える逆γ字状のパス取り形状の熱交換器のように、上記した３種類の熱交換器のいずれか複数種類を組み合わせて構成することも可能である。
【００４９】
この場合に、最下段の熱交換器として、下端部に氷結防止用伝熱管を備える熱交換器を配置することにより、ドレン水の量が多いときに熱交換器下端部で生じ易いドレン水の氷結も、これが速やかに溶かされ排出されることになって、ドレン水の量が多くなる大形の熱交換器でも全体的な除霜時間が短縮される。
【００５０】
なお、上記のように上下複数段の構成とする場合のフィン形状については、上下方向に一体のものとすることも、また、各熱交換器に対応して分離した形状とすることも可能である。
【００５１】
また、上記各形態では、セパレート形空気調和機の室外機に内装される熱交換器を例に挙げて説明したが、一体形空気調和機などのその他の形式の空気調和機に内装される熱交換器にも本発明を適用して構成することが可能である。
【００５２】
【発明の効果】
以上の説明のように、この発明の請求項１のクロスフィンチューブ型熱交換器においては、風上側と風下側との各伝熱管列を上下に分割し、これらを第１・第２中間部連絡管を設けて相互に接続した構成であるので、除霜運転時の冷媒の流通方向が暖房運転時とは逆になったときに、圧力損失に伴う冷媒温度の低下が大きくなる前に着霜量の多い風上側に冷媒を流通させることができる。これによって、風上側上半部に付着した霜を溶かし、さらに、霜が溶けて生じたドレン水によって、風上側下半部の除霜を促進することができる。この結果、全体的な除霜をより速やかに終了させて除霜運転時間を短縮することができるので、その分、暖房運転時間の割合が増加し、全体的な暖房能力が向上する。
【００５３】
請求項２のクロスフィンチューブ型熱交換器においては、風下側における下端側に流入した冷媒が風上側に一旦迂回して流通するようになっているので、霜が溶けて生じたドレン水の量が多く、これが次の暖房運転時に熱交換器の下端側で氷結した場合でも、除霜運転への切換時にこれが速やかに溶かされ排出されることになる。したがって、これによっても全体的な除霜時間を短縮することができる。
【００５４】
請求項３のクロスフィンチューブ型熱交換器においては、冷媒が側面視でγ字状に流通するパス取り形状であり、この場合も、除霜運転時に冷媒の流通方向が暖房運転時とは逆になると、冷媒は、風下側上部伝熱管列を通過後に風上側下部伝熱管列を流通する。したがって、この熱交換器においても、圧力損失に伴う冷媒温度の低下が大きくなる前に着霜量の多い風上側を冷媒が流通することになるので、前記した従来の逆Ｕ字状やＵ字状のパス取り形状を有する熱交換器に比べ、全体的な除霜時間を短縮することができる。
とができる。
【００５５】
請求項４のクロスフィンチューブ型熱交換器においては、上下複数段の熱交換器に互いに並列に冷媒を流通させることで、前述した効率的な除霜を各熱交換器毎に得ることができる。これにより、熱交換能力が大きく、かつ、除霜性能の良好な大形の熱交換器を得ることができる。
【００５６】
請求項５のクロスフィンチューブ型熱交換器においては、上下複数段の構成とする場合に、最下段に、氷結防止用伝熱管を下端側に備える熱交換器を配置するので、ドレン水の量が多いときに熱交換器下端部で生じ易いドレン水の氷結も、これが速やかに溶かされ排出されることになって、ドレン水の量が多くなる大形の熱交換器でも全体的な除霜時間を短縮することができる。
【図面の簡単な説明】
【図１】この発明の一実施形態におけるクロスフィンチューブ型熱交換器を示すもので、同図（ａ）は正面図、同図（ｂ）は側面図である。
【図２】上記熱交換器における除霜運転時の状態を説明するための斜視図である。
【図３】この発明の他の実施形態におけるクロスフィンチューブ型熱交換器を示すもので、同図（ａ）は斜視図、同図（ｂ）は側面図である。
【図４】この発明のさらに他の実施形態におけるクロスフィンチューブ型熱交換器を示す側面図である。
【図５】従来のクロスフィンチューブ型熱交換器を示すもので、同図（ａ）は正面図、同図（ｂ）は側面図である。
【図６】従来の他のクロスフィンチューブ型熱交換器の側面図である。
【符号の説明】
１熱交換器
２フィン
３伝熱管
４伝熱管
５伝熱管
６伝熱管
８風上側冷媒出入口管
９風下側冷媒出入口管
１０端部連絡管
１１第１中間部連絡管
１２第２中間部連絡管
２１第１熱交換部
２２第２熱交換部
２３第３熱交換部
２５第１下部連絡管
２６第２下部連絡管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cross fin tube type heat exchanger installed in an outdoor unit of a separate type air conditioner, for example.
[0002]
[Prior art]
As shown in FIG. 5A, the conventional cross fin tube type heat exchanger includes a large number of thin plate-like fins 31 and a plurality of straight tubular heat transfer tubes 32 and 33 penetrating these fins 31 horizontally. It is provided and configured. These heat transfer tubes 32 and 33 are juxtaposed at predetermined intervals along the two vertical planes on the front side and the back side of the paper so that the refrigerant circulates in the vertical direction while meandering. Are connected alternately.
[0003]
That is, each of the heat transfer tubes 32 and 33 is composed of a hairpin heat transfer tube in which two pipes from the lower stage side are connected to each other by a U-shaped curved pipe portion 34 on the right end side in the drawing, On the side, the refrigerant inlet / outlet pipes 32a and 33a, which are also shown in FIG. 5B, are connected to the lowermost heat transfer pipes 32 and 33, respectively, and the upper two pipes are connected to each other by the in-row connecting pipes 32b and 33b. ing. At the upper end, an end communication tube 35 that connects the ends of the uppermost heat transfer tubes 32 and 33 in each row is provided.
[0004]
When the outside air passes through the heat exchanger 30 in the direction as indicated in FIG. 4B, for example, as shown by the solid line arrow in the figure, when the refrigerant flows in through the windward side refrigerant inlet / outlet pipe 32a. The refrigerant sequentially passes through the leeward side heat transfer tube rows 32 from the lower side, and then sequentially passes through the leeward side heat transfer tube rows 33 from the upper side and flows out through the leeward side refrigerant inlet / outlet tube 33a. That is, the refrigerant flows from the windward side to the leeward side in an inverted U shape in a side view shown in FIG.
[0005]
When such a heat exchanger 30 is used as an outdoor heat exchanger in a separate air conditioner, and a refrigerant circulation circuit is configured by this, a compressor, a four-way switching valve, an indoor heat exchanger, and an expansion mechanism (not shown). In the cooling operation in which the heat exchanger 30 functions as a condenser, the refrigerant flows through the heat exchanger 30 from the leeward side to the windward side. In the heating operation in which the heat exchanger 30 functions as an evaporator, on the contrary, By circulating the refrigerant from the windward side to the leeward side, better heat exchange efficiency can be obtained in any case. Therefore, in the heat exchanger 30 described above, the refrigerant inlet / outlet pipe 32a on the windward side is connected to the indoor heat exchanger via the expansion mechanism, and the refrigerant inlet / outlet pipe 33a on the leeward side is connected to the compressor via the four-way switching valve. Connected. Thus, during the heating operation, the refrigerant flows from the windward side to the leeward side as indicated by the solid line arrow in FIG. 5B, and during the cooling operation performed by switching the four-way switching valve, it is indicated by the broken line arrow in the figure. Thus, the refrigerant flows from the leeward side to the leeward side.
[0006]
On the other hand, the cross fin tube type heat exchanger 40 shown in FIG. 6 is provided with refrigerant inlet / outlet pipes 32a and 33a at the uppermost stage in each row on the windward side and the leeward side, and the lowermost stages in each row are connected to the end. The tubes 35 are connected to each other. In this case, the refrigerant circulates in a U-shape when viewed from the side. However, the heat exchanger 40 having this configuration also causes the refrigerant to circulate from the windward side to the leeward side as indicated by the solid line arrow in the figure during heating operation. In the cooling operation, the refrigerant is interposed in the refrigerant circuit so that the refrigerant flows from the leeward side to the leeward side as indicated by broken line arrows in the figure.
[0007]
By the way, in the heating operation when the outside air temperature is low, such as in winter, frost is formed on the surface of the outdoor heat exchanger. Therefore, the heating operation is appropriately interrupted to perform the defrosting operation. In the reverse cycle defrost system, that is, in the state where the indoor fan is stopped, the high-temperature refrigerant discharged from the compressor is supplied to the outdoor heat exchanger by the switching operation of the four-way switching valve, and defrosting is performed. (B) and FIG. 6, respectively, as indicated by broken line arrows, the refrigerant flows through these heat exchangers 30 and 40 from the leeward side to the windward side in the same flow direction as in the cooling operation to perform defrosting. become.
[0008]
[Problems to be solved by the invention]
However, as in the reverse U-shaped type shown in FIG. 5 or the U-shaped type shown in FIG. 6, if the defrosting shape is such that the refrigerant flows from the leeward side to the windward side at the time of defrosting, defrosting is performed. As a result, there is a problem that sufficient heating capacity cannot be obtained.
[0009]
That is, frost formation during the heating operation occurs more on the windward side than on the leeward side in the heat exchanger, and more on the refrigerant outlet side. Therefore, when the refrigerant flow during the defrosting operation flows from the leeward side to the windward side, the frost in this region is melted by first passing through the region that was on the refrigerant outlet side during the heating operation. On the upper side, the refrigerant having a reduced condensation temperature according to the subsequent pressure loss flows. For this reason, it takes time to defrost the windward side where the amount of frost formation is large, or frost is left unmelted, resulting in a reduction in heating capacity.
[0010]
The present invention has been made in view of the above-described problems, and an object thereof is to provide a cross-fin tube heat exchanger that can further reduce the defrosting time and thereby improve the heating capacity. There is.
[0011]
[Means for Solving the Problems]
Therefore, the cross fin tube type heat exchanger according to claim 1 alternately connects both ends of a plurality of heat transfer tubes 3 to 6 arranged in parallel vertically at a predetermined interval so that the refrigerant circulates in the vertical direction while meandering. The formed heat transfer tube rows are arranged on the windward side and the leeward side, respectively, and the ends of the heat transfer tubes 3 and 5 at the upper ends of the windward side heat transfer tube row and the leeward side heat transfer tube row are connected to each other. At the end connection tube 10 A cross fin tube heat exchanger connected to each other, which divides the windward side heat transfer tube row and the leeward side heat transfer tube row into an upper heat transfer tube row and a lower heat transfer tube row, respectively, A first intermediate connecting pipe 11 that interconnects the ends of the heat transfer tube 3 at the lower end of the heat transfer tube row and the heat transfer tube 6 at the upper end of the lower heat transfer tube row on the leeward side, and the upper end of the lower heat transfer tube row on the leeward side A second intermediate connecting pipe 12 is provided for connecting the ends of the heat transfer tube 4 and the heat transfer tube 6 at the lower end of the upper heat transfer tube row on the leeward side. The refrigerant at the time of operation in which the windward side refrigerant inlet / outlet pipe 8 and the leeward side refrigerant inlet / outlet pipe 9 are connected to the heat transfer pipes 4 and 6 at the lower ends of the windward side heat transfer pipe row and the leeward side heat transfer tube row to function as an evaporator. Flows in through the windward side refrigerant inlet / outlet pipe 8 and sequentially passes through the windward lower side heat transfer pipe line, the leeward side upper heat transfer pipe line, the windward upper heat transfer pipe line, and the leeward side lower heat transfer pipe line from the leeward side refrigerant inlet / outlet pipe 9. It is configured to flow in the opposite direction to the above during defrosting operation. It is characterized by having.
[0012]
In this heat exchanger, the refrigerant flows through the heat transfer tubes 4 at the lower end of the windward lower heat transfer tube row during the heating operation, so that the refrigerant passes through each heat transfer tube 4 of the windward lower heat transfer tube row, It passes through the leeward upper heat transfer tube row, the windward upper heat transfer tube row, and the leeward lower heat transfer tube row in order, and circulates in an inverted γ shape in a side view.
[0013]
When the flow direction of the refrigerant is reversed in the defrosting operation, the refrigerant first passes through the leeward lower heat transfer tube row, that is, the refrigerant outlet side during the heating operation, and then the upwind upper transfer. It will circulate through the heat pipe line. Therefore, in particular, the frost adhering to the upper half of the windward side is melted by circulating on the windward side with a large amount of frost formation before the decrease in the refrigerant temperature due to the pressure loss becomes large. Furthermore, drain water generated by melting frost flows downward, and this drain water promotes defrosting of frost adhering to the lower half of the windward side. As a result, the overall defrosting can be completed more quickly, and the proportion of the heating operation time is increased accordingly, so that the overall heating capacity is improved.
[0014]
The cross fin tube type heat exchanger according to claim 2 is arranged on the leeward side so that the refrigerant flowing into the lower heat transfer tube row on the leeward side is circulated around the leeward side on the lower side of the lower heat transfer tube row on the leeward side. The heat transfer tube 6 on the lower end side of the lower heat transfer tube row is provided with an anti-icing heat transfer tube connected by lower communication tubes 25 and 26.
[0015]
According to this configuration, the refrigerant that has flowed into the lower end side of the leeward lower heat transfer tube row during the defrosting operation once bypasses the anti-icing heat transfer tube provided on the lower side of the windward lower heat transfer tube row, Circulates in reverse γ-shape. Therefore, as described above, on the windward side, frost adhering to the upper half is melted, and further, the frost in the lower half is melted and drained by the drain water generated by melting the frost. When the amount of water is large, the amount of drain water supplemented at the lower end of the heat exchanger increases, and this drain water is likely to freeze during heating operation. For this reason, the defrost time at the time of the next defrost operation becomes long. Therefore, once the refrigerant that has flowed into the leeward side during the defrosting operation is detoured to the lower end of the windward side, the drain water frozen as described above is also quickly melted and discharged. However, the overall defrosting time is shortened.
[0016]
The cross fin tube type heat exchanger according to claim 3 is formed by alternately connecting both ends of a plurality of heat transfer tubes 3 to 6 arranged in parallel vertically at a predetermined interval so that the refrigerant flows in the vertical direction while meandering. Are arranged on the windward side and the leeward side, respectively, and the ends of the heat transfer tubes 4 and 6 at the lower ends of the windward side heat transfer tube row and the leeward side heat transfer tube row are connected to each other. At the end connection tube 10 A cross fin tube heat exchanger connected to each other, which divides the windward side heat transfer tube row and the leeward side heat transfer tube row into an upper heat transfer tube row and a lower heat transfer tube row, respectively, A first intermediate connecting pipe 11 that interconnects the ends of the heat transfer tube 3 at the lower end of the heat transfer tube row and the heat transfer tube 6 at the upper end of the lower heat transfer tube row on the leeward side, and the upper end of the lower heat transfer tube row on the leeward side A second intermediate connecting pipe 12 is provided for connecting the ends of the heat transfer tube 4 and the heat transfer tube 6 at the lower end of the upper heat transfer tube row on the leeward side. The refrigerant at the time of operation in which the windward side refrigerant inlet / outlet pipe 8 and the leeward side refrigerant inlet / outlet pipe 9 are connected to the heat transfer pipes 3 and 5 at the upper ends of the windward side heat transfer pipe row and the leeward side heat transfer tube row to function as an evaporator. Flows in through the windward side refrigerant inlet / outlet pipe 8 and sequentially passes through the windward upper heat transfer pipe line, the leeward lower heat transfer pipe line, the windward lower heat transfer pipe line, and the leeward upper heat transfer pipe line from the leeward refrigerant inlet / outlet pipe 9. It is configured to flow in the opposite direction to the above during defrosting operation. It is characterized by having.
[0017]
In this configuration, since the heat transfer tubes 4 and 6 at the lower ends of the windward side heat transfer tube row and the leeward side heat transfer tube row are connected to each other, the refrigerant is placed at the upper end of the upper heat transfer tube row on the windward side during heating operation. By flowing into the heat transfer tubes, the refrigerant passes through each heat transfer tube of the windward upper heat transfer tube row, and then sequentially passes through the leeward lower heat transfer tube row, the windward lower heat transfer tube row, and the leeward upper heat transfer tube row. And it circulates in a γ shape in a side view.
[0018]
And if the distribution direction of a refrigerant | coolant becomes reverse with the above at the time of a defrost operation, a refrigerant | coolant will distribute | circulate an upwind lower heat exchanger tube row | line after passing a leeward upper heat exchanger tube row | line | column. Therefore, in this case as well, since the refrigerant flows through the windward side with a large amount of frost formation before the decrease in the refrigerant temperature due to pressure loss becomes large, the conventional inverted U-shape or U-shape described above is used. Compared with the heat exchanger having a pass shape, the overall defrosting time can be shortened.
[0019]
The cross fin tube type heat exchanger according to claim 4 is characterized in that one kind or plural kinds of heat exchangers according to any one of claims 1 to 3 are provided in a plurality of upper and lower stages.
[0020]
In this case, the efficient defrost mentioned above can be obtained for every heat exchanger by distribute | circulating a refrigerant | coolant mutually parallel to each heat exchanger. As a result, a large heat exchanger having a large heat exchange capacity and good defrosting performance can be obtained.
[0021]
The cross fin tube type heat exchanger according to claim 5 is characterized in that, in the heat exchanger according to claim 4, the heat exchanger according to claim 2 is arranged at the lowest stage.
[0022]
That is, when a large heat exchanger is configured as a plurality of upper and lower stages, a heat exchanger provided with an anti-icing heat transfer tube on the lower end side is disposed at the lowermost stage. As a result, similarly to the above, the freezing of drain water that is likely to occur at the lower end of the heat exchanger when the amount of drain water is large is quickly melted and discharged. Therefore, even with a large heat exchanger that increases the amount of drain water, the overall defrosting time can be shortened.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described in detail with reference to the drawings.
[0024]
As shown in FIG. 1A, a heat exchanger 1 according to the present embodiment includes a large number of thin plate-like fins 2 made of a metal having good heat conduction such as aluminum, and these fins 2 are horizontally arranged. A plurality of straight tubular heat transfer tubes 3 to 6 are provided. A plurality of these heat transfer tubes 3 to 6 are provided at predetermined intervals in the vertical direction along two vertical planes parallel to the paper surface, and eight in the illustrated case. In the following, the upper four heat transfer tubes 3 of the eight on the front side of the page are the upwind upper heat transfer tube row, the lower four heat transfer tubes 4 are the upwind lower heat transfer tube row, and the lower 8 on the paper side. The four heat transfer tubes 5 in the upper half of the book are referred to as the leeward upper heat transfer tube row, and the four heat transfer tubes 6 in the lower half are referred to as the leeward lower heat transfer tube row.
[0025]
In the drawing of each of the heat transfer tubes 3 to 6, two right end sides are sequentially connected by a U-shaped bent tube portion 7, two from the lower stage side. One bent tube portion 7 and a pair of heat transfer tubes extending horizontally from both upper and lower ends thereof are integrally formed by a hairpin heat transfer tube obtained by bending a straight tube 180 ° at its center. ing. Moreover, in the figure of each heat exchanger tube 3-6, as shown also in the figure (b), the left end side is the end part of the heat exchanger tubes of the 2nd step and the 3rd step from the bottom for every heat transfer tube row | line | column. Are connected to each other by U-shaped in-row connecting pipes 3a to 6a.
[0026]
And the windward side refrigerant inlet / outlet pipe 8 and the leeward side refrigerant inlet / outlet pipe 9 are respectively connected to the lower end heat transfer pipes 4 and 6 in the lower heat transfer pipe rows of the windward side and the leeward side, while the windward side and the leeward side The end portions of the heat transfer tubes 3 and 5 at the upper ends of the upper heat transfer tube rows are connected to each other by an end communication tube 10. Further, the ends of the lower end heat transfer tube 3 in the windward upper heat transfer tube row and the upper end heat transfer tube 6 in the leeward lower heat transfer tube row are connected to each other by the first intermediate connecting pipe 11, The ends of the upper heat transfer tube 4 in the upper lower heat transfer tube row and the lower heat transfer tube 5 in the leeward lower heat transfer tube row are connected to each other by the second intermediate connecting tube 12.
[0027]
The heat exchanger 1 having the above configuration is installed in an outdoor unit in a separate air conditioner so as to face an outdoor fan (not shown). At this time, if the outdoor air passing between the fins 2 as the outdoor fan is driven passes from right to left in FIG. 1B, the heat exchanger 1 is heated so as to function as an evaporator. During operation, the refrigerant is interposed in the refrigerant circuit so that the refrigerant flows in through the windward refrigerant inlet / outlet pipe 8 and flows out through the leeward refrigerant inlet / outlet pipe 9.
[0028]
At this time, the refrigerant flowing in through the windward side refrigerant inlet / outlet pipe 8 first passes through the heat transfer tubes 4 of the windward lower heat transfer tube row sequentially from the lower side, as indicated by solid arrows in the figure, and then the second intermediate portion. It flows into the heat transfer tube 5 at the lower end of the leeward upper heat transfer tube row through the connecting tube 12. Therefore, next, each heat transfer tube 5 of this heat transfer tube row is sequentially passed. After that, it flows into the heat transfer tube 3 at the upper end of the windward upper heat transfer tube row through the end communication tube 10, and sequentially passes through each heat transfer tube 3 of this heat transfer tube row from the upper side, and then passes through the first intermediate connection tube 11 to the leeward side. The heat transfer tube 6 is sent to the upper heat transfer tube 6 at the upper end of the lower heat transfer tube row, and sequentially passes through the heat transfer tubes 6 of the heat transfer tube row, and then flows out through the leeward refrigerant inlet / outlet tube 9.
[0029]
As described above, the heat exchanger 1 is formed in a path removing shape in which the refrigerant flow has a substantially inverted γ shape in a side view shown in FIG. During the heating operation, when the refrigerant flows through the heat exchanger 1 through the above path, the refrigerant absorbs heat from the outside air passing between the fins 2 and evaporates, and this heat energy is radiated indoors by the indoor heat exchanger. The
[0030]
By the way, when the heating operation as described above is continued in a state where the outside air temperature is low, frost formation is gradually generated in the heat exchanger 1, thereby impairing the circulation of the outside air and lowering the heat exchange efficiency. Accordingly, the defrosting operation can be switched to the defrosting operation as appropriate. When this is performed by the reverse cycle defrosting operation in which the indoor fan in the indoor unit is stopped and the refrigerant circulation cycle is reversed, the heat exchanger 1 is changed. The flow direction of the refrigerant passing through is opposite to the above. That is, as indicated by broken line arrows in FIG. 1 (b), first, the refrigerant flows through the leeward refrigerant inlet / outlet pipe 9, and then the lower half of the leeward side, the upper half of the leeward side, and the upper half of the leeward side. Then, the air passes through the lower half of the windward side and flows out through the windward side refrigerant inlet / outlet pipe 8.
[0031]
As described above, when the refrigerant flow is generated in the opposite direction to that in the heating operation during the defrosting operation, the defrosting operation is efficiently performed because of the above-described reverse γ-shaped path removing shape. . That is, frost formation accompanying the continuation of heating operation occurs more on the windward side than on the leeward side, and more on the refrigerant outlet side. On the other hand, when the refrigerant flow during defrosting is switched as described above, the refrigerant first passes through the refrigerant outlet side during heating operation, that is, the lower half of the leeward side to dissipate heat. It will melt the frost produced in the area. And the refrigerant | coolant condensed with the heat dissipation in this area | region gradually falls with the pressure loss at the time of passing through this heat exchanger 1, but the above-mentioned leeward side lower half part Next, since it is sent to the upper half of the windward side, the refrigerant in a higher temperature state flows through this region.
[0032]
As a result, as shown in FIG. 2, a sufficient amount of heat is given to the frost generated in the upper half of the windward side from the refrigerant flowing through this region, and this is quickly melted, and drain water 13 is formed as the fin 2. It flows down.
[0033]
On the other hand, the lower half of the windward side is an area where the refrigerant finally circulates through the heat transfer tube 4 in this area. Therefore, the refrigerant at this time has a temperature drop. When the drain water 13 flows down from the upper upper half part through the fins 2, heat is also given from the drain water 13 to the frost generated in the upper windward lower half part. As a result, defrosting in this region can also be caused promptly. As a result, defrosting in a short time is possible over the entire heat exchanger 1.
[0034]
As described above, better heat exchange efficiency can be obtained by flowing the refrigerant from the windward side to the leeward side during the heating operation. However, in the heat exchanger 1, each upper heat transfer tube row is from the leeward side. Since the refrigerant flows to the windward side, the above relationship is not satisfied, and as a result, the efficiency of the heat exchanger during the heating operation slightly decreases. However, as described above, the defrosting operation time can be shortened, so that the heating operation time becomes longer, and thereby the overall heating performance can be improved.
[0035]
FIG. 3 shows a cross fin tube heat exchanger 1 according to another embodiment of the present invention. As shown in FIG. 1A, the overall shape of the heat exchanger 1 is substantially L-shaped in plan view. As shown in FIG. 1B, this heat exchanger 1 has three upper and lower stages each adopting a reverse γ-shaped pass-taking shape, almost the same as the heat exchanger shown in FIG. The heat exchangers 21 to 23 are provided. In the present embodiment, the fins 2 are not vertically separated for each of the heat exchangers 21 to 23, and are formed in an integrated shape over the entire vertical direction. Therefore, in the following description, the upper heat exchanger is referred to as the first heat exchange unit 21, the middle heat exchanger is referred to as the second heat exchange unit 22, and the lower heat exchanger is referred to as the third heat exchange unit 23.
[0036]
The uppermost first heat exchange section 21 is provided with refrigerant inlet / outlet pipes 8a and 9a on the windward side and leeward side on the lower end side, respectively, and is connected to the end communication pipe 10 on the upper end side at an intermediate height position. The heat transfer tubes on the windward side and the leeward side are connected to each other by the first intermediate portion connecting tube 11 and the second intermediate portion connecting tube 12 that intersect with each other. Similarly, the refrigerant inlet / outlet pipes 8b and 9b are respectively provided on the windward side and the leeward side of the lower end side of the second heat exchanger 22 in the middle stage, and the end part on the upper end side of the second heat exchanger 22 is communicated. The heat transfer tubes on the leeward side and the leeward side are connected to each other by the tube 10 and the first and second intermediate portion connecting tubes 11 and 12 at the intermediate height position. The lower third heat exchange section 23 is also provided with refrigerant inlet / outlet pipes 8c and 9c on the windward side and leeward side on the lower end side, respectively, and the end communication pipe 10 on the upper end side in the third heat exchanger 23. And the heat transfer tubes on the leeward side and the leeward side are connected to each other by the first and second intermediate portion connecting pipes 11 and 12 at the intermediate height position.
[0037]
And each upwind side refrigerant | coolant inlet / outlet pipe | tube 8a-8c of the 1st-3rd heat exchange parts 21-23 is each connected to the unillustrated upwind header for dividing or confluence | merging a refrigerant | coolant, and each leeward side refrigerant | coolant similarly. The entrance / exit pipes 9a to 9c are connected to the leeward header. Therefore, for example, when the refrigerant is supplied to the heat exchanger 1 through the windward header, as shown by the one-dot chain line arrow in FIG. Corresponding refrigerant flows occur in parallel with each other, and merge and flow out at the leeward header.
[0038]
In addition, at the lower end side of the third heat exchanging portion 23, as shown in FIG. 5A, one further anti-icing heat transfer tube 24 is provided below the leeward refrigerant inlet / outlet tube 9c. . The left end side of the heat transfer tube 24 is connected to the heat transfer tube 6 to which the leeward refrigerant inlet / outlet tube 9c is connected via the bent tube portion 7. On the other hand, although not shown, two anti-icing heat transfer tubes connected to each other on the left end side are further provided below the windward side refrigerant inlet / outlet tube 8c. Of these, the end of the lower heat transfer tube and the end of the leeward anti-icing heat transfer tube 24 are connected to each other by a first lower connecting tube 25 shown in FIG. Further, the end of the upper heat transfer tube of the leeward anti-icing heat transfer tube is connected to the end of the heat transfer tube located in the upper stage of the leeward refrigerant inlet / outlet tube 9c via the second lower connecting pipe 26. Has been.
[0039]
With such a configuration, when the refrigerant flows through the leeward refrigerant inlet / outlet pipe 9c in the direction opposite to the one-dot chain line arrow in FIG. 5B during the defrosting operation described later, this refrigerant is used for preventing icing on the leeward side. After passing through the heat transfer tube 24, it is sent to the windward side through the first lower connecting tube 25, and passes through the two heat transfer tubes for preventing freezing on the windward side. Thereafter, it is sent to the leeward side through the second lower connecting pipe 26, and thereafter flows through the third heat exchanging portion 23 in accordance with the reverse γ-shaped path taking shape and flows out through the windward side refrigerant inlet / outlet pipe 8c. It will be.
[0040]
In the heat exchanger 1 configured as described above, similarly to the heat exchanger described with reference to FIG. 1, during the heating operation, the refrigerant has passed through the heat exchange units 21 to 23 as indicated by the one-dot chain line arrows in the figure. Later, it is interposed in the refrigerant circuit so as to flow out through the leeward refrigerant inlet / outlet pipes 9a to 9c.
[0041]
And at the time of a defrost operation, a refrigerant | coolant will distribute | circulate each heat exchange part 21-23 in the reverse direction to the above, and, thereby, a refrigerant | coolant is from every leeward lower half part for every heat exchange part 21-23. Distributes to the upper half of the windward side. Therefore, similarly to the above, when the higher-temperature refrigerant passes through the region where the amount of frost formation is large, frost in the upper half of the windward side in particular is quickly melted. It will be promoted by drain water flowing down from the upper half, and defrosting over the whole can be completed in a short time.
[0042]
In addition, in the heat exchanger 1 which provided the three-stage heat exchange parts 21-23 as mentioned above and was enlarged, the whole amount of frost formation increases. Along with this, the amount of drain water flowing down through the fins 2 increases, the amount of drain water supplemented at the lower end of the heat exchanger increases, and this drain water is likely to freeze during heating operation. And at the next defrosting operation, it becomes necessary to melt and discharge this frozen drain water, and the defrosting time becomes longer.
[0043]
In such a case, in the heat exchanger 1, as described above, the high-temperature refrigerant that has flowed into the lower end side of the third heat exchange section 23 through the leeward refrigerant inlet / outlet pipe 9c is once detoured to the windward side. A refrigerant is circulated through a heat transfer tube for preventing freezing. As a result, the drain water frozen on the lower end side of the heat exchanger 1 is also quickly melted and discharged, and this also shortens the overall defrosting time.
[0044]
FIG. 4 shows a cross fin tube heat exchanger 1 according to still another embodiment of the present invention. The heat exchanger 1 connects the windward side refrigerant inlet / outlet pipe 8 and the leeward side refrigerant inlet / outlet pipe 9 to the respective heat transfer pipes at the upper ends of the upper heat transfer pipe rows on the windward side and the leeward side, and communicates with the ends. The tube 10 is provided between the end portions of the heat transfer tubes at the lower end of each lower heat transfer tube row, and is configured in a substantially γ-shaped path removing shape.
[0045]
In this case, as indicated by a solid line arrow, the refrigerant flows through the windward side refrigerant inlet / outlet pipe 8 during the heating operation, so that the refrigerant passes through each heat transfer pipe of the windward upper side heat transfer pipe row and then the leeward side lower heat transfer pipe. It passes through the row, the leeward lower heat transfer tube row, and the leeward upper heat transfer tube row in sequence, and circulates in a γ shape in a side view.
[0046]
During the defrosting operation, as indicated by the broken-line arrows in the figure, when the flow direction of the refrigerant is opposite to the above, the refrigerant flows through the leeward lower heat transfer tube row after passing through the leeward upper heat transfer tube row. Therefore, in this case as well, since the refrigerant flows through the windward side with a large amount of frost formation before the decrease in the refrigerant temperature due to pressure loss becomes large, the conventional inverted U-shape or U-shape described above is used. Compared to a heat exchanger having a pass shape, the overall defrosting time can be shortened.
[0047]
Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, in the embodiment described with reference to FIG. 3, the configuration in which the first to third heat exchanging units 21 to 23 each having an inverted γ-shaped path-taking shape are provided in upper and lower stages is taken as an example. A heat exchanger having a heat transfer tube for preventing icing at the lower end as in the third heat exchanging portion 23 in FIG. 3 is arranged in multiple upper and lower stages, and the heat having the γ-shaped path taking shape described with reference to FIG. It is also possible to adopt a configuration in which the exchangers are provided in multiple upper and lower stages.
[0048]
Further, for example, a heat exchanger having a reverse γ-shaped pass-taking shape at the uppermost stage, a heat exchanger having a γ-shaped pass-taking shape at the middle stage, and a reverse γ provided with a heat transfer tube for preventing freezing at the lower end part. It is also possible to configure a combination of a plurality of types of the above-described three types of heat exchangers, such as a letter-shaped pass shape heat exchanger.
[0049]
In this case, by arranging a heat exchanger having an anti-icing heat transfer tube at the lower end as the lowermost heat exchanger, the drain water that is likely to be generated at the lower end of the heat exchanger when the amount of drain water is large. Freezing is also quickly melted and discharged, so that the overall defrosting time is shortened even in a large heat exchanger with a large amount of drain water.
[0050]
In addition, about the fin shape in the case of having a plurality of upper and lower stages as described above, it is possible to make it integral in the vertical direction or to have a shape separated according to each heat exchanger. is there.
[0051]
In each of the above embodiments, the heat exchanger installed in the outdoor unit of the separate air conditioner has been described as an example. However, the heat installed in other types of air conditioners such as an integrated air conditioner has been described. The present invention can also be applied to the exchanger.
[0052]
【The invention's effect】
As described above, in the cross fin tube heat exchanger according to the first aspect of the present invention, the heat transfer tube rows on the windward side and the leeward side are divided into upper and lower parts, and these are divided into the first and second intermediate portions. Since the connecting pipes are connected to each other, when the refrigerant flow direction during the defrosting operation is opposite to that during the heating operation, it is reached before the refrigerant temperature drop due to pressure loss increases. The refrigerant can be circulated to the windward side where the amount of frost is large. Thereby, the frost adhering to the upper half of the windward side can be melted, and further, defrosting of the lower half of the windward side can be promoted by the drain water generated by melting the frost. As a result, since the overall defrosting can be completed more quickly and the defrosting operation time can be shortened, the proportion of the heating operation time is increased accordingly, and the overall heating capacity is improved.
[0053]
In the cross fin tube type heat exchanger according to claim 2, since the refrigerant flowing into the lower end side on the leeward side is once detoured and circulated to the leeward side, the amount of drain water generated by melting of frost Even when this freezes on the lower end side of the heat exchanger during the next heating operation, it is quickly melted and discharged when switching to the defrosting operation. Therefore, the overall defrosting time can also be shortened by this.
[0054]
In the cross-fin tube type heat exchanger according to claim 3, the refrigerant is in a shape of a path that circulates in a γ shape in a side view. In this case, the refrigerant flow direction is opposite to that in the heating operation during the defrosting operation. Then, the refrigerant flows through the leeward lower heat transfer tube row after passing through the leeward upper heat transfer tube row. Therefore, in this heat exchanger as well, since the refrigerant flows through the windward side with a large amount of frost formation before the decrease in the refrigerant temperature due to pressure loss becomes large, the conventional reverse U-shape or U-shape described above is used. The overall defrosting time can be shortened as compared with a heat exchanger having a shape of a pass-taking shape.
You can.
[0055]
In the cross fin tube type heat exchanger according to claim 4, the above-mentioned efficient defrosting can be obtained for each heat exchanger by allowing the refrigerant to flow in parallel to each other in the upper and lower stages of the heat exchanger. . As a result, a large heat exchanger having a large heat exchange capacity and good defrosting performance can be obtained.
[0056]
In the cross fin tube type heat exchanger according to claim 5, when the heat exchanger is provided with a plurality of upper and lower stages, a heat exchanger provided with a heat transfer tube for preventing freezing on the lower end side is disposed at the lowermost stage. Freezing of drain water, which is likely to occur at the lower end of the heat exchanger when there is a large amount of water, is also quickly melted and discharged, so that even large heat exchangers with a large amount of drain water can be totally defrosted. Time can be shortened.
[Brief description of the drawings]
FIG. 1 shows a cross-fin tube heat exchanger according to an embodiment of the present invention, in which FIG. 1 (a) is a front view and FIG. 1 (b) is a side view.
FIG. 2 is a perspective view for explaining a state during a defrosting operation in the heat exchanger.
FIGS. 3A and 3B show a cross fin tube heat exchanger according to another embodiment of the present invention, in which FIG. 3A is a perspective view and FIG. 3B is a side view.
FIG. 4 is a side view showing a cross fin tube heat exchanger according to still another embodiment of the present invention.
FIGS. 5A and 5B show a conventional cross fin tube heat exchanger, in which FIG. 5A is a front view, and FIG. 5B is a side view.
FIG. 6 is a side view of another conventional cross fin tube type heat exchanger.
[Explanation of symbols]
1 heat exchanger
2 Fin
3 Heat transfer tubes
4 Heat transfer tubes
5 Heat transfer tubes
6 Heat transfer tubes
8 Upwind refrigerant inlet / outlet pipe
9 Downward refrigerant inlet / outlet pipe
10 End connection pipe
11 First intermediate section communication pipe
12 Second intermediate section communication pipe
21 1st heat exchange part
22 2nd heat exchange part
23 Third heat exchange section
25 First lower connecting pipe
26 Second lower connecting pipe

Claims

冷媒が蛇行しながら上下方向に流通するように上下に所定の間隔で並設した複数の伝熱管（３〜６）の両端を交互に接続して形成した伝熱管列を風上側と風下側とにそれぞれ配置し、風上側伝熱管列と風下側伝熱管列との各上端の伝熱管（３）（５）の端部同士を端部連絡管（１０）で相互に接続して成るクロスフィンチューブ型熱交換器であって、風上側伝熱管列と風下側伝熱管列とをそれぞれ上部伝熱管列と下部伝熱管列とに分割すると共に、風上側の上部伝熱管列下端の伝熱管（３）と風下側の下部伝熱管列上端の伝熱管（６）との各端部同士を相互に接続する第１中間部連絡管（１１）と、風上側の下部伝熱管列上端の伝熱管（４）と風下側の上部伝熱管列下端の伝熱管（６）との各端部同士を相互に接続する第２中間部連絡管（１２）とを設け、風上側伝熱管列と風下側伝熱管列との各下端の各伝熱管（４）（６）に風上側冷媒出入口管（８）と風下側冷媒出入口管（９）とを接続し、蒸発器として機能させる運転時に冷媒が風上側冷媒出入口管（８）を通して流入し、風上側下部伝熱管列、風下側上部伝熱管列、風上側上部伝熱管列、風下側下部伝熱管列を順次通過して風下側冷媒出入口管（９）から流出し、除霜運転時には上記とは逆の流れとなるべく構成されていることを特徴とするクロスフィンチューブ型熱交換器。A heat transfer tube array formed by alternately connecting both ends of a plurality of heat transfer tubes (3 to 6) arranged in parallel at predetermined intervals in the vertical direction so that the refrigerant flows in the vertical direction while meandering, each on the cross fin formed by connecting together at the heat transfer tube of each upper end of the upwind heat transfer tube bank and downwind heat transfer tube bank (3) end communication pipe ends (5) (10) It is a tube type heat exchanger, and the windward side heat transfer tube row and the leeward side heat transfer tube row are respectively divided into an upper heat transfer tube row and a lower heat transfer tube row, and a heat transfer tube at the lower end of the windward upper heat transfer tube row ( 3) and a first intermediate connecting pipe (11) for mutually connecting the ends of the lower heat transfer tube row on the leeward side and the heat transfer tube on the upper end of the lower heat transfer tube row on the leeward side. A second intermediate connecting pipe (1) connecting the ends of (4) and the heat transfer pipe (6) at the lower end of the upper heat transfer pipe row on the leeward side (1) ) And the provided, each heat transfer tube of each lower end of the upwind heat transfer tube bank and downwind heat transfer tube bank (4) (6) on the upwind side refrigerant inlet and outlet pipe (8) and the leeward side refrigerant inlet and outlet pipes and (9) During operation to connect and function as an evaporator, the refrigerant flows in through the windward side refrigerant inlet / outlet pipe (8), and the windward lower heat transfer tube row, the leeward upper heat transfer tube row, the windward upper heat transfer tube row, the leeward lower heat transfer tube A cross fin tube type heat exchanger characterized in that it is configured to pass through the rows in order to flow out of the leeward refrigerant inlet / outlet pipe (9) and to have a flow opposite to the above during the defrosting operation .

風上側の下部伝熱管列の下側に、風下側の下部伝熱管列に流入した冷媒が風上側に迂回して流通するように、風下側の下部伝熱管列下端側の伝熱管（６）に下部連絡管（２５）（２６）で接続した氷結防止用伝熱管を設けていることを特徴とする請求項１のクロスフィンチューブ型熱交換器。 A heat transfer tube (6) on the lower end side of the lower heat transfer tube row on the leeward side so that the refrigerant flowing into the lower heat transfer tube row on the leeward side is circulated around the lower side of the windward lower heat transfer tube row. The cross fin tube type heat exchanger according to claim 1, further comprising an anti-icing heat transfer tube connected by a lower communication tube (25) (26).

冷媒が蛇行しながら上下方向に流通するように上下に所定の間隔で並設した複数の伝熱管（３〜６）の両端を交互に接続して形成した伝熱管列を風上側と風下側とにそれぞれ配置し、風上側伝熱管列と風下側伝熱管列との各下端の伝熱管（４）（６）の端部同士を端部連絡管（１０）で相互に接続して成るクロスフィンチューブ型熱交換器であって、風上側伝熱管列と風下側伝熱管列とをそれぞれ上部伝熱管列と下部伝熱管列とに分割すると共に、風上側の上部伝熱管列下端の伝熱管（３）と風下側の下部伝熱管列上端の伝熱管（６）との各端部同士を相互に接続する第１中間部連絡管（１１）と、風上側の下部伝熱管列上端の伝熱管（４）と風下側の上部伝熱管列下端の伝熱管（６）との各端部同士を相互に接続する第２中間部連絡管（１２）とを設け、風上側伝熱管列と風下側伝熱管列との各上端の各伝熱管（３）（５）に風上側冷媒出入口管（８）と風下側冷媒出入口管（９）とを接続し、蒸発器として機能させる運転時に冷媒が風上側冷媒出入口管（８）を通して流入し、風上側上部伝熱管列、風下側下部伝熱管列、風上側下部伝熱管列、風下側上部伝熱管列を順次通過して風下側冷媒出入口管（９）から流出し、除霜運転時には上記とは逆の流れとなるべく構成されていることを特徴とするクロスフィンチューブ型熱交換器。A heat transfer tube array formed by alternately connecting both ends of a plurality of heat transfer tubes (3 to 6) arranged in parallel at predetermined intervals in the vertical direction so that the refrigerant flows in the vertical direction while meandering, Cross fins that are arranged in the upper end and the ends of the heat transfer tubes (4), (6) at the lower ends of the windward side heat transfer tube row and the leeward side heat transfer tube row are connected to each other by an end portion connecting tube (10). It is a tube type heat exchanger, and the windward side heat transfer tube row and the leeward side heat transfer tube row are respectively divided into an upper heat transfer tube row and a lower heat transfer tube row, and a heat transfer tube at the lower end of the windward upper heat transfer tube row ( 3) and a first intermediate connecting pipe (11) for mutually connecting the ends of the lower heat transfer tube row on the leeward side and the heat transfer tube on the upper end of the lower heat transfer tube row on the leeward side. A second intermediate connecting pipe (1) connecting the ends of (4) and the heat transfer pipe (6) at the lower end of the upper heat transfer pipe row on the leeward side (1) ) And the provided, each heat transfer tube of each upper end of the upwind heat transfer tube bank and downwind heat transfer tube bank (3) (5) on the windward side refrigerant inlet and outlet pipe (8) and the leeward side refrigerant inlet and outlet pipes and (9) During operation to connect and function as an evaporator, the refrigerant flows in through the windward side refrigerant inlet / outlet tube (8), and the windward upper heat transfer tube row, the leeward lower heat transfer tube row, the windward lower heat transfer tube row, the leeward upper heat transfer tube A cross fin tube type heat exchanger characterized in that it is configured to pass through the rows in order to flow out of the leeward refrigerant inlet / outlet pipe (9) and to have a flow opposite to the above during the defrosting operation .

請求項１〜３のいずれかの熱交換器の１種類又は複数種類を上下複数段設けていることを特徴とするクロスフィンチューブ型熱交換器。 A cross fin tube type heat exchanger in which one or more types of heat exchangers according to any one of claims 1 to 3 are provided in a plurality of stages.

請求項２の熱交換器を最下段に配置したことを特徴とする請求項４のクロスフィンチューブ型熱交換器。 The heat exchanger of Claim 2 was arrange | positioned in the lowest stage, The cross fin tube type heat exchanger of Claim 4 characterized by the above-mentioned.