JP2004361023A

JP2004361023A - Air conditioner

Info

Publication number: JP2004361023A
Application number: JP2003161148A
Authority: JP
Inventors: Hiroyuki Arakawa; 裕幸荒川; Takao Ogawa; 貴生小川
Original assignee: Toshiba Carrier Corp
Current assignee: Toshiba Carrier Corp
Priority date: 2003-06-05
Filing date: 2003-06-05
Publication date: 2004-12-24
Anticipated expiration: 2023-06-05
Also published as: JP4266131B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner having improved air conditioning performance while controlling the amount of refrigerant during cooling and heating operation to minimize the influences on cost. <P>SOLUTION: An indoor heat exchanger 5 as part of a heat pump type refrigerating cycle consists of a combination of a main heat exchanger 13 and an auxiliary heat exchanger 14. The auxiliary heat exchanger is located in a cooling cycle at the introduction side of the refrigerant, namely, in a heating cycle at the delivery side of the refrigerant. The main heat exchanger and the auxiliary heat exchanger are each constituted by a plurality of fins f arranged side by side at spaces and heat exchanger pipes p passing through the fins. The pipe diameter of the heat exchanger pipe p2 as part of the auxiliary heat exchanger is set larger than the pipe diameter of the heat exchanger pipe p1 as part of the main heat exchanger. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、冷暖房運転の切換えが可能なヒートポンプ式の冷凍サイクルを構成する空気調和機に係り、特に、室内熱交換器の改良に関する。
【０００２】
【従来の技術】
一般家庭用として、冷暖房運転の切換えが可能なヒートポンプ式の冷凍サイクルを備えた空気調和機では、室内機と室外機とから構成されるタイプのものが多用されている。上記室内機には室内熱交換器および室内送風機が配置され、室外機には圧縮機と、室外熱交換器および室外送風機他が配置される。室内機と室外機は冷媒管と電気配線を介して接続される。
【０００３】
上記室内熱交換器は、狭小の間隙を存して並設されるフィンに熱交換パイプが貫通して構成される。上記熱交換パイプの管径の設定は、室内熱交換器の熱交換効率に影響があり、かつ熱交換器としての外形サイズの設定にも影響がある。結局、現在のところ８ｍｍ以下の管径であれば熱交換効率の保持と外形サイズの拡大抑制に有利であるとの結論が得られている。
【０００４】
しかしながら、その一方で、システムとしての省エネルギー性の点から室外熱交換器の容積も大きくなり、それにともない冷媒量の増大傾向が避けられない。このことから、室外熱交換器を凝縮器とする冷房サイクルと、室内熱交換器を凝縮器とする暖房サイクルとでは、最高性能を引出すことができる冷媒量に差が生じている。
【０００５】
すなわち、冷房運転と暖房運転との最適冷媒量を比較すると、冷房運転時の方が冷媒量が多い。これは、暖房運転時の蒸発性能確保のために、室外熱交換器を室内熱交換器よりも大きくした成形したことによる。室外熱交換器が大きいので、室外熱交換器が凝縮器となる冷房運転時においてここに溜められる冷媒量が、暖房運転時に室内熱交換器に溜められる冷媒量より多くなる。
【０００６】
［特許文献１］には、ヒートポンプ式冷凍サイクルの主回路を備えた空気調和機において、この主回路中に冷媒中の水分を吸着するドライヤを備え、このドライヤの容積を乾燥剤が封入される以上の容積にしてドライヤ内部に空間を形成し、暖房運転時にドライヤ内部に形成した空間に一部の冷媒を溜める技術が開示されている。
【０００７】
【特許文献１】
特開２００１−１３２９８７号公報
【０００８】
【発明が解決しようとする課題】
すなわち、暖房運転時に気液分離装置およびドライヤ内を密度の高い液相冷媒が貫流する。そこで、ドライヤ内部に乾燥剤の封入部以上の空間を、また気液分離装置に必要以上の空間を設定し、この空間内に液相冷媒を溜められるようにして、冷房運転時および暖房運転時で冷媒量を調整する。空間の大きさを適当にすることによって運転状態に応じて冷媒量は適正に調整される、とある。
【０００９】
しかしながら、このような作用効果を得るためには、ドライヤと気液分離器を通常のものよりも大型化しなければならず、それにともないこれらドライヤと気液分離器を収容する室外機の筐体の大型化と、室外機据付けスペースの拡大化に繋がる。さらには、これら構成部品の製作コストに影響が出て、空気調和機自体のコストに影響を及ぼしてしまう。
【００１０】
従来においては、上述のようにドライヤと気液分離器を対象とするばかりではなく、たとえば電子膨張弁と室内熱交換器との間に、暖房時に循環する冷媒の一部を溜めて同様の作用効果を得る考えもある。この場合においても、別途、タンクを用意して取付ける手間がかかり、同様の不具合が発生してしまう。
【００１１】
本発明は上記事情に着目してなされたものであり、その目的とするところは、冷房運転時および暖房運転時で冷媒量を調整でき、コストに与える影響を最小限に抑制したうえで、空調性能の向上化を図った空気調和機を提供しようとするものである。
【００１２】
【課題を解決するための手段】
上記課題を解決し目的を達成するために本発明は、圧縮機と、四方切換え弁と、室外熱交換器と、減圧装置および室内熱交換器を冷媒管を介してヒートポンプ式の冷凍サイクルを構成するよう連通する空気調和機において、上記室内熱交換器は、主熱交換器および補助熱交換器との組み合わせからなり、補助熱交換器を冷房サイクルの冷媒導入側で暖房サイクルの冷媒導出側に位置させ、これら主熱交換器および補助熱交換器は間隙を存して並設する複数枚のフィンとフィンを貫通する熱交換パイプとから構成し、補助熱交換器を構成する熱交換パイプの管径は主熱交換器を構成する熱交換パイプの管径よりも大に設定した。
【００１３】
【発明の実施の形態】
以下、本発明の実施の形態を図面にもとづいて説明する。
図１は空気調和機の冷凍サイクル構成図、図２は空気調和機を構成する室内機の概略の断面図、図３は室内熱交換器の冷媒流路を説明する図である。
【００１４】
はじめに図１の冷凍サイクルから説明すると、圧縮機１と、四方切換え弁２と、室外熱交換器３と、減圧装置である電子膨張弁４および室内熱交換器５が冷媒管Ｐを介してヒートポンプ式の冷凍サイクルを構成するよう連通されてなる。
【００１５】
上記室外熱交換器３は、２列のＬ型熱交換器部を並列に並べていて、上記四方切換え弁２から延出される冷媒管Ｐは室外熱交換器３の直前で２方向分岐管６の各分岐部に接続される。各分岐部は、室外熱交換器３を構成するそれぞれの熱交換器部の一方端に接続される。
【００１６】
また、上記熱交換器部の他方端にも分岐冷媒管が接続されていて、それぞれの分岐冷媒管は補助毛細管７を介して２方向分岐管８の分岐部に接続される。この２方向分岐管８の合流部は、上記電子膨張弁４を介して室内熱交換器５に連通する冷媒管Ｐに接続される。
【００１７】
上記室内熱交換器５と四方切換え弁２とを連通する冷媒管Ｐと、室内熱交換器５と電子膨張弁４とを連通する冷媒管Ｐのそれぞれにはパックドバルブ９が設けられる。このパックドバルブ９から一方側は室外機１Ａであり、他方側は室内機１Ｂである。室内熱交換器５は室内機１Ｂに収容され、圧縮機１、四方切換え弁２、室外熱交換器３、電子膨張弁４などは室外機１Ａに収容される。
【００１８】
図１において、実線矢印は冷房（または除湿）サイクルの冷媒の流れ方向を示し、破線矢印は暖房サイクルの冷媒の流れ方向を示している。すなわち、上記四方切換え弁２を切換えて冷媒の流れ方向を変更することにより、室内熱交換器５で冷媒が蒸発して室内空気から蒸発潜熱を奪う冷房（または除湿）運転と、室内熱交換器５で冷媒が凝縮して室内空気に凝縮熱を放出する暖房運転との切換えができるようになっている。
【００１９】
つぎに、上記室内機１Ｂについて説明する。室内機１Ｂは、前面パネル１０と後板１１とからなる筐体１２内に、側面視で略逆Ｖ字状に形成される上記室内熱交換器５を備えている。この室内熱交換器５は、主熱交換器１３と、補助熱交換器１４との組み合わせからなる。
【００２０】
上記主熱交換器５は、略Ｖ字状の前面側にあり略円弧状断面に形成される前側熱交換器部１３Ａと、後面側にあり斜め直状に形成される後側熱交換器部１３Ｂを備えている。上記補助熱交換器１４は、斜め直状に形成され、後側熱交換器部１３Ｂの上部に所定の間隙を存して並行に沿う。このことにより、補助熱交換器１４と後側熱交換器部１３Ｂとは互いに熱的に遮断されている。
【００２１】
上記前面パネル１０の前面側に前部吸込み口１５が設けられ、上面側に上部吸込み口１６が設けられていて、それぞれの吸込み口１５，１６にはグリルが嵌め込まれている。上記室内熱交換器５の主熱交換器１３を構成する前側熱交換器部１３Ａは前部吸込み口１５に対向し、前側熱交換器部１３Ａの一部と後側熱交換器部１３Ｂおよび補助熱交換器１４は上部吸込み口１６に対向している。
【００２２】
主熱交換器１３を構成する前側熱交換器部１３Ａと後側熱交換器部１３Ｂとの間には横流ファン１６が配置され、これら熱交換器部１３Ａ，１３Ｂで覆われる。上記横流ファン１６の一端部にファンモータが連結され、これらで室内送風機が構成される。上記前部吸込み口１５の下方部位で筐体１０の前面側下部にはルーバー１７を備えた吹出し口１８が設けられる。
【００２３】
このようにして構成される室内機１Ｂであって、横流ファン１６を回転駆動することにより前部吸込み口１５と上部吸込み口１６から室内空気が筐体１０内に吸込まれる。筐体１０内において室内空気は、前部吸込み口１５と対向する前側熱交換器部１３Ａを流通し、上部吸込み口１６と対向する前側熱交換器部１３Ａ一部と補助熱交換器１４および後側熱交換器部１３Ｂを流通する。
【００２４】
室内空気が前側熱交換器部１３Ａと後側熱交換器部１３Ｂおよび補助熱交換器１４をそれぞれ流通している間に、各熱交換器に導かれる冷媒と熱交換して、吹出し口１８から室内へ吹出される。熱交換空気が室内に導かれて、冷房（もしくは除湿）もしくは暖房作用を得られる。
【００２５】
なお、上記補助熱交換器１４は上部吸込み口１６に直接対向して配置されていて、補助熱交換器１４は室内空気流に対して主熱交換器１３を構成する後側熱交換器部１３Ｂよりも上流側に位置する。換言すれば、後側熱交換器部１３Ｂは主熱交換器１３を構成するから、補助熱交換器１４は室内空気流の最上流側に位置することになる。
【００２６】
さらに、室内熱交換器５について詳述する。この室内熱交換器５を構成する主熱交換器１３（前側熱交換器部１３Ａおよび後側熱交換器部１３Ｂ）と補助熱交換器１４ともに、所定の間隙を存して並設される複数枚のフィンｆと、これらフィンｆを貫通する熱交換パイプｐとから構成される。
【００２７】
上記室内熱交換器５は、主熱交換器１３を構成する前側熱交換器部１３Ａと後側熱交換器部１３Ｂおよび補助熱交換器１４の他に、除湿用絞り弁１９を備えている。図１では前側熱交換器部１３Ａと後側熱交換器部１３Ｂとの間に除湿用絞り弁１９が介在しているが、実際には図３で後述するような流路構成において用いられている。
【００２８】
そして、ここでは補助熱交換器１４に用いられる熱交換パイプｐ２の管径（約７ｍｍ）は、主熱交換器１３を構成する前側熱交換器部１３Ａおよび後側熱交換器部１３Ｂに用いられる熱交換パイプｐ１の管径（約φ６．３５ｍｍ）よりも大に形成されることを特徴の一つとしている。
【００２９】
室内熱交換器５における実際の流路構成を図３から説明する。冷房サイクルを基準にすると、傾斜した補助熱交換器１４の傾斜下端部が冷媒の導入部ａとなる。上記電子膨張弁４から導かれる液冷媒は補助熱交換器１４に導入され、この傾斜上端まで導かれてから導出される。補助熱交換器１４から出た冷媒は、前側熱交換器部１３Ａの前列（室内空気流の風上側）上部に設けられる２方向分岐管２０の合流部に導かれる。
【００３０】
この２方向分岐管２０において冷媒は２方向に分流され、その一方は前側熱交換器部１３Ａの上端を介して後側熱交換器部１３Ｂの上部側列（室内空気流の風上側）上端に分流される。さらに、この後側熱交換器部１３Ｂの下端まで導かれたあと、下部側列（室内空気流の風下側）の上端に導かれる。そして、後側熱交換器部１３Ｂから出て、外部に設けられる２方向分岐管２１の一方の分岐部に導かれる。
【００３１】
また、前側熱交換器部１３Ａの前列の２方向分岐管２０で分流される他方側の冷媒は、そのまま前側熱交換器部１３Ａの下部側へ導かれ、この下部側で後列（室内空気流の風下側）に移る。さらに、上端部まで行ってから外部に設けられる上記２方向分岐管２１の他方の分岐部に導かれる。
【００３２】
この２方向分岐管２１の合流部には、中途部に上記除湿用絞り弁１７が設けられるジャンピング管２２の一端が接続されている。このジャンピング管２２の他端部にも２方向分岐管２３の合流部が接続されていて、一方の分岐部は前側熱交換器部１３Ａの下部前列から一端上部に行ってから後列に移る。そして、後列では一端下部側に移ってから後列に設けられる別の２方向分岐管２４の一方の分岐部に導かれる。
【００３３】
また、上記ジャンピング管２２他端部の２方向分岐管２３における他方の分岐部に導かれる冷媒は前側熱交換器部１３Ａの前列下端まで導かれてから、後列側に移る。ここから一旦上部側に行って、後列側に設けられる上記２方向分岐管２４の他方の分岐部に導かれる。この２方向分岐管２４の合流部に上記四方切換え弁２に連通する冷媒管Ｐが接続されていて、室内熱交換器５における冷媒導出部ｂとなる。
【００３４】
暖房サイクルでは、冷房サイクルとは逆サイクルとなっていて、前側熱交換器部１３Ａの後列下部に接続される２方向分岐管２４の合流部が冷媒導入部ｂとなり、補助熱交換器１４の傾斜下端の冷媒接続部が冷媒導出部ａとなる。
【００３５】
上記補助熱交換器１４を基準にしてみると、この補助熱交換器１４は冷房サイクルにおいて冷媒導入側となり、暖房サイクルにおいて冷媒導出側に位置する。そして、先に説明したように補助熱交換器１４を構成する熱交換パイプｐ２の管径を、主熱交換器１３を構成する前後側熱交換器部１３Ａ，１３Ｂの熱交換パイプｐ１の管径よりも大に設定している。
【００３６】
このようにして、冷房サイクルでは熱交換パイプｐ２の管径の大きい補助熱交換器１４が冷媒導入側となっているので、冷媒導入側において圧力損失の低減を得られ、冷房性能の向上に寄与する。暖房サイクルでは冷媒導出側に位置する補助熱交換器１４の熱交換パイプｐ２の管径が大きいので、ここに冷媒を溜められ、よって暖房性能の向上に寄与する。
【００３７】
すなわち、冷房サイクルと暖房サイクルとの最適冷媒量を比較すると、冷房サイクル時の方が冷媒量が多い。これは、暖房サイクル時の蒸発性能を確保するのに室外熱交換器３を室内熱交換器５よりも大型にしている。したがって、室外熱交換器３が凝縮器となる冷房サイクル時において室外熱交換器３に蓄えられる冷媒量が暖房サイクル時に室内熱交換器５に蓄えられる冷媒量よりも多くなる。
【００３８】
冷房運転と暖房運転ともに最適運転を行うために、各運転時に冷媒量を調整して暖房運転時の余分な液冷媒をサイクルの一部に溜めることにより性能が向上する。そこで、暖房運転時に補助熱交換器１４が冷媒導出側となり、密度の高い液相冷媒が導かれるのを利用し、上述の設定をなすことにより冷媒量を適正に調整でき暖房能力の向上を得る。
【００３９】
本発明では、従来のように暖房運転時に液冷媒を一旦溜めるタンクを備えたり、あるいは［特許文献１］にあるように必要以上の容積のドライヤや気液分離器を別途用意する必要がない。これらの技術と比較して、コストに与える影響が小さくてすむ。
【００４０】
また、補助熱交換器１４は、室内送風機（横流ファン１６）の作動にともない前、上吸込み口１５ａ、１５ｂから吸込まれて吹出し口１８から吹出される室内空気流の最上部に配置されることになる。その一方で、補助熱交換器１４は暖房サイクルで冷媒導出側にあり、ここで効率よく熱交換して凝縮した冷媒が略過冷却状態になり、暖房性能の向上に繋げられる。
【００４１】
冷房サイクルでは補助熱交換器１４が冷媒導入側になるので、室内空気流の最上部にある補助熱交換器１４での熱交換効率が向上して圧力損失の低減が得られ、補助熱交換器１４から出て前側熱交換器部１３Ａの前列に設けられる２方向分岐管２０での分流が安定化する。
【００４２】
また、補助熱交換器１４は、主熱交換器１３を構成する前後側熱交換器部１３Ａ，１３Ｂのような前後２列の流路構成とは相違して１列の流路構成であり、１パスとなっている。したがって、補助熱交換器１４を製作するにあたって２列構成の熱交換器部１３Ａ，１３Ｂと比較して配管コストの低減を得られる。
【００４３】
また、補助熱交換器１４は、後側熱交換器部１３Ｂと所定の間隙を存して並行して設けられているので、互いに熱的に遮断されている。このことから、冷媒導入側もしくは冷媒導出側にある補助熱交換器１４と、冷媒導通の途中にある後側熱交換器部１３Ｂとの間に熱交換がなく、先に説明した補助熱交換器１４の作用とその効果を確保できる。
【００４４】
また、補助熱交換器１４と後側熱交換器部１３Ｂとを熱的に遮断するには、必ずしも別体構造とする必要はなく、一体フィンでありながら、相互間にスリット（切欠部）を入れて略別体構造としてもよい。
【００４５】
また、上記補助熱交換器１４はそれ自体、単体構造としたが、これに限定されるものではなく、複数個の別体化された補助熱交換器部の集合体としても適用できる。この場合は、さらに性能改善効果を高められる。
【００４６】
また、補助熱交換器１４は主熱交換器１３と比較して伝熱特性が劣る構成にして、さらにコストの抑制を図ることができる。すなわち、補助熱交換器１４は暖房サイクルにおいて冷媒導出側であり、冷凍サイクル的にアンダークール域として熱伝達特性が低下する領域である。したがって、補助熱交換器１４を構成するフィンｆの枚数を少なくしてコストの低減を図り、フィンｆ相互間隔を広げて伝熱特性の低下を図っても、性能への影響が少なくてすむ。
【００４７】
また、補助熱交換器１４の熱交換パイプｐ２の管径をＡとし、主熱交換器１３を構成する前後側熱交換器部１３Ａ，１３Ｂの熱交換パイプｐ１の管径をＢとしたとき、
Ａ／Ｂ＝１．０５〜１．１５
となるように設定する。種々の実験と経験から、これ以下の値では先に述べた効果が得られない。これ以上の値では、先に述べた補助熱交換器１４からの分流の効果が得られないとともに、コストへ与える影響があり、室内機１Ｂの筐体寸法の拡大に繋がってしまう。
【００４８】
【発明の効果】
以上説明したように本発明によれば、暖房運転時の余分な液冷媒を室内熱交換器を構成する補助熱交換器に溜めることにより、冷房運転時および暖房運転時で冷媒量を調整でき、コストに与える影響を最小限に抑制したうえで、空調性能の向上化を得る等の効果を奏する。
【図面の簡単な説明】
【図１】本発明の実施の形態に係る、空気調和機の冷凍サイクル構成図。
【図２】同実施の形態に係る、空気調和機を構成する室内機の縦断面図。
【図３】同実施の形態に係る、室内熱交換器の流路構成の説明図。
【符号の説明】
１…圧縮機、２…四方切換え弁、３…室外熱交換器、４…電子膨張弁、５…室内熱交換器、１３…主熱交換器、１４…補助熱交換器、ｐ２…（補助熱交換器の）熱交換パイプ、ｐ１…（主熱交換器の）熱交換パイプ、１６…上部吸込み口、１８…吹出し口、１６…横流ファン（室内送風機）。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air conditioner constituting a heat pump type refrigeration cycle capable of switching between cooling and heating operations, and more particularly to an improvement in an indoor heat exchanger.
[0002]
[Prior art]
As a general household, an air conditioner having a heat pump type refrigerating cycle capable of switching between a cooling operation and a heating operation is frequently used which includes an indoor unit and an outdoor unit. The indoor unit is provided with an indoor heat exchanger and an indoor blower, and the outdoor unit is provided with a compressor, an outdoor heat exchanger, an outdoor blower, and the like. The indoor unit and the outdoor unit are connected via a refrigerant pipe and electric wiring.
[0003]
The indoor heat exchanger is configured such that a heat exchange pipe penetrates fins arranged side by side with a small gap. The setting of the diameter of the heat exchange pipe affects the heat exchange efficiency of the indoor heat exchanger, and also affects the setting of the outer size of the heat exchanger. As a result, it has been concluded that a tube diameter of 8 mm or less is advantageous for maintaining heat exchange efficiency and suppressing an increase in the outer size.
[0004]
However, on the other hand, the capacity of the outdoor heat exchanger also increases from the viewpoint of energy saving as a system, and a tendency to increase the amount of refrigerant is inevitable. For this reason, there is a difference between the cooling cycle in which the outdoor heat exchanger is used as the condenser and the heating cycle in which the indoor heat exchanger is used as the condenser.
[0005]
That is, when comparing the optimum refrigerant amount between the cooling operation and the heating operation, the refrigerant amount is larger during the cooling operation. This is because the outdoor heat exchanger was formed larger than the indoor heat exchanger in order to ensure the evaporating performance during the heating operation. Since the outdoor heat exchanger is large, the amount of refrigerant stored therein during the cooling operation in which the outdoor heat exchanger functions as a condenser is larger than the amount of refrigerant stored in the indoor heat exchanger during the heating operation.
[0006]
[Patent Document 1] discloses an air conditioner including a main circuit of a heat pump refrigeration cycle, including a dryer that adsorbs moisture in a refrigerant in the main circuit, and a desiccant is filled in a volume of the dryer. A technology is disclosed in which a space is formed inside the dryer with the above volume, and a part of the refrigerant is stored in the space formed inside the dryer during the heating operation.
[0007]
[Patent Document 1]
JP-A-2001-132987
[Problems to be solved by the invention]
That is, the liquid refrigerant having a high density flows through the gas-liquid separator and the dryer during the heating operation. Therefore, a space larger than the desiccant enclosing part inside the dryer and a space more than necessary in the gas-liquid separation device are set so that the liquid-phase refrigerant can be stored in this space, so that the cooling operation and the heating operation can be performed. To adjust the amount of refrigerant. It is stated that by appropriately setting the size of the space, the amount of the refrigerant is appropriately adjusted according to the operation state.
[0009]
However, in order to obtain such effects, the dryer and the gas-liquid separator must be made larger than usual, and accordingly, the housing of the outdoor unit accommodating the dryer and the gas-liquid separator is required. This leads to an increase in the size and the installation space for outdoor units. Furthermore, the production cost of these components is affected, which affects the cost of the air conditioner itself.
[0010]
Conventionally, not only the dryer and the gas-liquid separator are targeted as described above, but also, for example, a part of the refrigerant circulating at the time of heating is stored between the electronic expansion valve and the indoor heat exchanger to perform the same operation. There are thoughts to be effective. Also in this case, it takes time and labor to separately prepare and attach the tank, and the same problem occurs.
[0011]
The present invention has been made in view of the above circumstances, and an object thereof is to adjust the amount of refrigerant during cooling operation and heating operation, to minimize the effect on cost, and to control air conditioning. It is an object of the present invention to provide an air conditioner with improved performance.
[0012]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, the present invention provides a heat pump type refrigeration cycle including a compressor, a four-way switching valve, an outdoor heat exchanger, a pressure reducing device and an indoor heat exchanger via a refrigerant pipe. In the air conditioner that communicates with the indoor heat exchanger, the indoor heat exchanger includes a combination of a main heat exchanger and an auxiliary heat exchanger, and the auxiliary heat exchanger is connected to a refrigerant introduction side of a cooling cycle and to a refrigerant discharge side of a heating cycle. The main heat exchanger and the auxiliary heat exchanger are composed of a plurality of fins arranged side by side with a gap and a heat exchange pipe passing through the fins. The pipe diameter was set to be larger than the pipe diameter of the heat exchange pipe constituting the main heat exchanger.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a refrigeration cycle of an air conditioner, FIG. 2 is a schematic sectional view of an indoor unit constituting the air conditioner, and FIG. 3 is a diagram illustrating a refrigerant flow path of an indoor heat exchanger.
[0014]
First, the refrigeration cycle of FIG. 1 will be described. A compressor 1, a four-way switching valve 2, an outdoor heat exchanger 3, an electronic expansion valve 4 as a decompression device, and an indoor heat exchanger 5 are connected via a refrigerant pipe P to a heat pump. The refrigeration cycle is configured to be in communication.
[0015]
The outdoor heat exchanger 3 has two rows of L-type heat exchangers arranged in parallel, and the refrigerant pipe P extending from the four-way switching valve 2 is connected to the two-way branch pipe 6 immediately before the outdoor heat exchanger 3. Connected to each branch. Each branch part is connected to one end of each heat exchanger part constituting the outdoor heat exchanger 3.
[0016]
A branch refrigerant pipe is also connected to the other end of the heat exchanger section, and each branch refrigerant pipe is connected to a branch portion of the two-way branch pipe 8 via the auxiliary capillary 7. The junction of the two-way branch pipe 8 is connected to a refrigerant pipe P communicating with the indoor heat exchanger 5 via the electronic expansion valve 4.
[0017]
Packed valves 9 are provided in each of the refrigerant pipes P connecting the indoor heat exchanger 5 and the four-way switching valve 2 and the refrigerant pipes P connecting the indoor heat exchanger 5 and the electronic expansion valve 4. One side from the packed valve 9 is the outdoor unit 1A, and the other side is the indoor unit 1B. The indoor heat exchanger 5 is housed in the indoor unit 1B, and the compressor 1, the four-way switching valve 2, the outdoor heat exchanger 3, the electronic expansion valve 4, and the like are housed in the outdoor unit 1A.
[0018]
In FIG. 1, the solid arrows indicate the flow direction of the refrigerant in the cooling (or dehumidification) cycle, and the dashed arrows indicate the flow direction of the refrigerant in the heating cycle. That is, by changing the flow direction of the refrigerant by switching the four-way switching valve 2, the refrigerant evaporates in the indoor heat exchanger 5 to remove the latent heat of evaporation from the indoor air. The operation can be switched to a heating operation in which the refrigerant is condensed and the condensed heat is released to the indoor air at 5.
[0019]
Next, the indoor unit 1B will be described. The indoor unit 1B includes the indoor heat exchanger 5 formed in a substantially inverted V-shape in a side view in a housing 12 including a front panel 10 and a rear plate 11. This indoor heat exchanger 5 is composed of a combination of a main heat exchanger 13 and an auxiliary heat exchanger 14.
[0020]
The main heat exchanger 5 includes a front heat exchanger section 13A formed on a substantially V-shaped front side and having a substantially arc-shaped cross section, and a rear heat exchanger section formed on a rear side and formed obliquely and straight. 13B. The auxiliary heat exchanger 14 is formed obliquely straight, and runs in parallel with a predetermined gap above the rear heat exchanger section 13B. Thus, the auxiliary heat exchanger 14 and the rear heat exchanger section 13B are thermally isolated from each other.
[0021]
A front suction port 15 is provided on the front side of the front panel 10, and an upper suction port 16 is provided on the upper surface side. A grill is fitted in each of the suction ports 15, 16. The front heat exchanger section 13A constituting the main heat exchanger 13 of the indoor heat exchanger 5 is opposed to the front suction port 15, and a part of the front heat exchanger section 13A, the rear heat exchanger section 13B and the auxiliary heat exchanger section 13B. The heat exchanger 14 faces the upper suction port 16.
[0022]
A cross flow fan 16 is arranged between the front heat exchanger section 13A and the rear heat exchanger section 13B constituting the main heat exchanger 13, and is covered by these heat exchanger sections 13A and 13B. A fan motor is connected to one end of the cross flow fan 16, and these constitute an indoor blower. An outlet 18 provided with a louver 17 is provided at a lower portion on the front side of the housing 10 below the front inlet 15.
[0023]
In the indoor unit 1 </ b> B configured as described above, the room air is sucked into the housing 10 from the front suction port 15 and the upper suction port 16 by rotating and driving the cross flow fan 16. In the casing 10, the indoor air flows through the front heat exchanger section 13A facing the front suction port 15, and a part of the front heat exchanger section 13A facing the upper suction port 16, the auxiliary heat exchanger 14, and the rear. Flow through the side heat exchanger section 13B.
[0024]
While the room air is flowing through the front heat exchanger section 13A, the rear heat exchanger section 13B, and the auxiliary heat exchanger 14, respectively, it exchanges heat with the refrigerant guided to each heat exchanger, and It is blown out to the room. The heat exchange air is guided into the room to obtain a cooling (or dehumidifying) or heating effect.
[0025]
The auxiliary heat exchanger 14 is disposed directly opposite the upper suction port 16, and the auxiliary heat exchanger 14 is a rear heat exchanger 13B that constitutes the main heat exchanger 13 for indoor airflow. It is located on the upstream side. In other words, since the rear heat exchanger section 13B constitutes the main heat exchanger 13, the auxiliary heat exchanger 14 is located on the most upstream side of the indoor air flow.
[0026]
Further, the indoor heat exchanger 5 will be described in detail. A plurality of main heat exchangers 13 (front heat exchanger section 13A and rear heat exchanger section 13B) and auxiliary heat exchanger 14 that constitute indoor heat exchanger 5 are arranged side by side with a predetermined gap. It is composed of a plurality of fins f and a heat exchange pipe p penetrating these fins f.
[0027]
The indoor heat exchanger 5 includes a dehumidifying throttle valve 19 in addition to the front heat exchanger 13A, the rear heat exchanger 13B, and the auxiliary heat exchanger 14, which constitute the main heat exchanger 13. Although the dehumidifying throttle valve 19 is interposed between the front heat exchanger section 13A and the rear heat exchanger section 13B in FIG. 1, it is actually used in a flow path configuration as described later with reference to FIG. I have.
[0028]
And here, the pipe diameter (about 7 mm) of the heat exchange pipe p2 used for the auxiliary heat exchanger 14 is used for the front heat exchanger 13A and the rear heat exchanger 13B constituting the main heat exchanger 13. One of the features is that the heat exchange pipe p1 is formed larger than the pipe diameter (about φ6.35 mm).
[0029]
The actual flow path configuration in the indoor heat exchanger 5 will be described with reference to FIG. On the basis of the cooling cycle, the lower end of the inclined auxiliary heat exchanger 14 becomes the refrigerant introduction part a. The liquid refrigerant guided from the electronic expansion valve 4 is introduced into the auxiliary heat exchanger 14, and is guided to the upper end of the slope before being discharged. The refrigerant that has flowed out of the auxiliary heat exchanger 14 is guided to the junction of the two-way branch pipe 20 provided above the front row of the front heat exchanger section 13A (upstream of the indoor airflow).
[0030]
In the two-way branch pipe 20, the refrigerant is diverted in two directions, one of which is located at the upper end of the upper row (windward of the indoor airflow) of the rear heat exchanger section 13B via the upper end of the front heat exchanger section 13A. Shunted. Further, after being guided to the lower end of the rear heat exchanger section 13B, it is guided to the upper end of the lower side row (the leeward side of the indoor air flow). Then, it exits from the rear heat exchanger section 13B and is guided to one branch of a two-way branch pipe 21 provided outside.
[0031]
Further, the refrigerant on the other side, which is divided by the two-way branch pipe 20 in the front row of the front heat exchanger section 13A, is guided to the lower side of the front heat exchanger section 13A as it is, and the rear side (in the indoor air flow) Leeward side). Further, after reaching the upper end portion, it is guided to the other branch portion of the two-way branch pipe 21 provided outside.
[0032]
One end of a jumping pipe 22 provided with the dehumidifying throttle valve 17 in the middle thereof is connected to the junction of the two-way branch pipe 21. The junction of the two-way branch pipe 23 is also connected to the other end of the jumping pipe 22. One branch section goes from the lower front row of the front heat exchanger section 13A to one end upper section and then moves to the rear row. Then, in the rear row, one end is moved to the lower side, and then guided to one branch portion of another two-way branch pipe 24 provided in the rear row.
[0033]
Further, the refrigerant guided to the other branch of the two-way branch pipe 23 at the other end of the jumping pipe 22 is guided to the lower end of the front row of the front heat exchanger section 13A, and then moves to the rear row. From there, it goes once to the upper side and is led to the other branch of the two-way branch pipe 24 provided in the rear row. A refrigerant pipe P communicating with the four-way switching valve 2 is connected to a junction of the two-way branch pipe 24 and serves as a refrigerant outlet b in the indoor heat exchanger 5.
[0034]
In the heating cycle, the cycle is the reverse of the cooling cycle, and the junction of the two-way branch pipe 24 connected to the lower part of the rear row of the front heat exchanger section 13A becomes the refrigerant introduction section b, and the inclination of the auxiliary heat exchanger 14 The refrigerant connection part at the lower end becomes the refrigerant outlet part a.
[0035]
Referring to the auxiliary heat exchanger 14, the auxiliary heat exchanger 14 is located on the refrigerant introduction side in the cooling cycle and is located on the refrigerant outlet side in the heating cycle. As described above, the pipe diameter of the heat exchange pipe p2 forming the auxiliary heat exchanger 14 is changed to the pipe diameter of the heat exchange pipe p1 of the front and rear heat exchanger sections 13A and 13B forming the main heat exchanger 13. It is set larger than.
[0036]
In this manner, in the cooling cycle, the auxiliary heat exchanger 14 having a large diameter of the heat exchange pipe p2 is on the refrigerant introduction side, so that a pressure loss can be reduced on the refrigerant introduction side, contributing to the improvement of the cooling performance. I do. In the heating cycle, since the diameter of the heat exchange pipe p2 of the auxiliary heat exchanger 14 located on the refrigerant outlet side is large, the refrigerant can be stored here, thereby contributing to the improvement of the heating performance.
[0037]
That is, comparing the optimal refrigerant amount between the cooling cycle and the heating cycle, the refrigerant amount is larger during the cooling cycle. This makes the outdoor heat exchanger 3 larger than the indoor heat exchanger 5 to secure the evaporation performance during the heating cycle. Therefore, the amount of refrigerant stored in the outdoor heat exchanger 3 during the cooling cycle in which the outdoor heat exchanger 3 functions as a condenser is larger than the amount of refrigerant stored in the indoor heat exchanger 5 during the heating cycle.
[0038]
In order to perform the optimal operation for both the cooling operation and the heating operation, the performance is improved by adjusting the amount of the refrigerant during each operation and storing the excess liquid refrigerant during the heating operation in a part of the cycle. Therefore, during the heating operation, the auxiliary heat exchanger 14 is on the refrigerant outlet side, and the high-density liquid-phase refrigerant is guided. By making the above setting, the amount of the refrigerant can be appropriately adjusted to improve the heating capacity. .
[0039]
According to the present invention, there is no need to provide a tank for temporarily storing the liquid refrigerant during the heating operation as in the related art, or to separately prepare a dryer or a gas-liquid separator having an unnecessarily large volume as disclosed in [Patent Document 1]. Compared with these technologies, the influence on cost is small.
[0040]
The auxiliary heat exchanger 14 is arranged at the uppermost part of the indoor airflow that is sucked from the upper suction ports 15a and 15b and blown out from the blowout port 18 before the indoor blower (cross flow fan 16) is operated. become. On the other hand, the auxiliary heat exchanger 14 is on the refrigerant outlet side in the heating cycle, and the refrigerant condensed by efficiently exchanging heat here is in a substantially supercooled state, leading to an improvement in heating performance.
[0041]
In the cooling cycle, since the auxiliary heat exchanger 14 is on the refrigerant introduction side, the heat exchange efficiency of the auxiliary heat exchanger 14 at the uppermost part of the room air flow is improved, and the pressure loss is reduced. The branch flow from the two-way branch pipe 20, which is provided at the front row of the front heat exchanger section 13A after exiting from the front heat exchanger section 13A, is stabilized.
[0042]
The auxiliary heat exchanger 14 has a single-row flow path configuration unlike the front-back two-row flow path configuration such as the front-rear heat exchanger sections 13A and 13B constituting the main heat exchanger 13, One pass. Therefore, in manufacturing the auxiliary heat exchanger 14, the piping cost can be reduced as compared with the heat exchanger sections 13A and 13B having the two-row configuration.
[0043]
Further, since the auxiliary heat exchanger 14 is provided in parallel with the rear heat exchanger section 13B with a predetermined gap, it is thermally isolated from each other. From this, there is no heat exchange between the auxiliary heat exchanger 14 on the refrigerant introduction side or the refrigerant discharge side and the rear heat exchanger section 13B in the middle of the refrigerant conduction, and the auxiliary heat exchanger described above 14 and its effects can be secured.
[0044]
Further, in order to thermally cut off the auxiliary heat exchanger 14 and the rear heat exchanger section 13B, it is not always necessary to form the auxiliary heat exchanger 14 and the rear heat exchanger section 13B separately. It may be inserted into a substantially separate structure.
[0045]
Further, the auxiliary heat exchanger 14 has a single-piece structure itself, but is not limited thereto, and may be applied as an aggregate of a plurality of separate auxiliary heat exchanger units. In this case, the performance improvement effect can be further enhanced.
[0046]
Further, the auxiliary heat exchanger 14 has a configuration in which the heat transfer characteristics are inferior to those of the main heat exchanger 13, so that the cost can be further reduced. That is, the auxiliary heat exchanger 14 is on the refrigerant outlet side in the heating cycle, and is an area where the heat transfer characteristic is reduced as an undercool area in a refrigeration cycle. Therefore, the cost is reduced by reducing the number of fins f constituting the auxiliary heat exchanger 14, and even if the interval between the fins f is increased to lower the heat transfer characteristic, the effect on the performance is reduced.
[0047]
When the pipe diameter of the heat exchange pipe p2 of the auxiliary heat exchanger 14 is A, and the pipe diameter of the heat exchange pipe p1 of the front and rear heat exchanger sections 13A and 13B constituting the main heat exchanger 13 is B,
A / B = 1.05 to 1.15
Set so that From various experiments and experiences, the above-mentioned effects cannot be obtained with a value below this value. If the value is larger than this, the effect of the above-described split flow from the auxiliary heat exchanger 14 cannot be obtained, and there is an effect on the cost, which leads to an increase in the housing size of the indoor unit 1B.
[0048]
【The invention's effect】
As described above, according to the present invention, by storing excess liquid refrigerant during the heating operation in the auxiliary heat exchanger that constitutes the indoor heat exchanger, the refrigerant amount can be adjusted during the cooling operation and the heating operation, The effects of minimizing the influence on the cost and improving the air conditioning performance are obtained.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a refrigeration cycle of an air conditioner according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the indoor unit constituting the air conditioner according to the embodiment.
FIG. 3 is an explanatory diagram of a channel configuration of the indoor heat exchanger according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... 4-way switching valve, 3 ... Outdoor heat exchanger, 4 ... Electronic expansion valve, 5 ... Indoor heat exchanger, 13 ... Main heat exchanger, 14 ... Auxiliary heat exchanger, p2 ... (Auxiliary heat Heat exchange pipe (of the exchanger), p1 ... heat exchange pipe (of the main heat exchanger), 16 ... upper inlet, 18 ... outlet, 16 ... cross flow fan (indoor blower).

Claims

In a compressor, a four-way switching valve, an outdoor heat exchanger, an air conditioner that communicates a pressure reducing device and an indoor heat exchanger via a refrigerant pipe so as to form a heat pump type refrigeration cycle,
The indoor heat exchanger comprises a combination of a main heat exchanger and an auxiliary heat exchanger,
Positioning the auxiliary heat exchanger on the refrigerant introduction side of the cooling cycle and on the refrigerant outlet side of the heating cycle,
Each of the main heat exchanger and the auxiliary heat exchanger includes a plurality of fins, each of which is juxtaposed with a gap, and a heat exchange pipe penetrating the fins.
The air conditioner according to claim 1, wherein a diameter of a heat exchange pipe constituting the auxiliary heat exchanger is set to be larger than a diameter of a heat exchange pipe constituting the main heat exchanger.

The indoor heat exchanger is installed in a room and is arranged together with an indoor blower in an indoor unit having an inlet and an outlet.
2. The air conditioner according to claim 1, wherein the auxiliary heat exchanger is arranged at an uppermost stream of an indoor airflow that is sucked from a suction port and blown out from an outlet when the indoor blower is operated. 3. .