JP3866359B2 - Air conditioner - Google Patents

Description

【０００１】
【発明の属する技術分野】
この発明は、作動媒体としてハイドロフルオロカ−ボン系の冷媒を、冷凍機油としてこの冷媒と相溶性のある油を用いる空気調和装置に関する。
【０００２】
【従来の技術】
図２８は、従来の空気調和装置の冷媒回路図で、図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、６は暖房時絞り装置（以下第２の絞り装置という）、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは冷房時絞り装置（以下第１の絞り装置という）、９は、熱源機Ａの熱源機側熱交換器３側の一端と室内機Ｂ、Ｃ、Ｄの第１の絞り装置８ｂ、８ｃ、８ｄ側の一端とを接続する液側接続冷媒配管、１０は、熱源機Ａの上記切換弁２側の一端と室内機Ｂ、Ｃ、Ｄの室内機側熱交換器７ｂ、７ｃ、７ｄ側の一端とを接続するガス側接続冷媒配管、１１，１２は、合成ゼオライトなどを主成分とする乾燥剤を円筒容器や配管内に内蔵させた、冷媒回路中に混入した水分を吸湿するドライヤ、１３，１４ｂ、１４ｃ、１４ｄは、細かい網目状のフィルタを円筒容器や配管内に内蔵してスラッジを捕捉するスラッジフィルタである。
【０００３】
次に、冷媒の流れを図によって説明する。図中実線矢印が冷房時の流れを、破線矢印が暖房時の流れを示す。まず、冷房時においては、圧縮機１で高温高圧まで圧縮されたガス冷媒は切換弁２を経て熱源機側熱交換器３に流入し、空気などと熱交換して凝縮し、高温高圧の液冷媒となる。さらに、冷房時全開の第２の絞り装置６、液側接続冷媒配管９をへて、室内機Ｂ、Ｃ、Ｄに達し、室内機側熱交換器７ｂ、７ｃ、７ｄの出口の過熱度が一定範囲になるように制御される第１の絞り装置８ｂ、８ｃ、８ｄによって、低圧の気液ニ相状態まで絞られる。低圧の気液ニ相冷媒は室内機側熱交換器７ｂ、７ｃ、７ｄに流入して、室内の空気と熱交換してガス化し、ガス側接続冷媒配管１０、切換弁２、アキュムレ−タ４を経て圧縮機１へ戻る。アキュムレ−タ４内部の冷凍機油は液冷媒とともに油戻し穴５より圧縮機１へ戻る。
【０００４】
暖房時においては、圧縮機１で高温高圧まで圧縮されたガス冷媒は切換弁２、ガス側接続冷媒配管１０を経て、室内機Ｂ、Ｃ、Ｄに達し、室内機側熱交換器７ｂ、７ｃ、７ｄに流入し、室内の空気と熱交換して凝縮し、高温高圧の液冷媒となる。室内側熱交換器７ｂ、７ｃ、７ｄを出た液冷媒はほとんど全開状態の第１の絞り装置７ｂ、７ｃ、７ｄで少し減圧され、液側接続冷媒配管９をへて第２の絞り装置６に達し、ここで低圧の気液ニ相状態まで絞られる。低圧の気液ニ相冷媒は熱源機側熱交換器３に流入し、空気などと熱交換してガス化し、切換弁２、アキュムレ−タ４を経て圧縮機１へ戻る。アキュムレ−タ４内部の冷凍機油は液冷媒とともに油戻し穴５より圧縮機１へ戻る。
【０００５】
以上のような冷媒回路において、作動媒体としてハイドロクロロフルオロカーボン系の冷媒の代りに最近ハイドロフルオロカ−ボン系の冷媒が用いられてきた。ところが、ハイドロフルオロカ−ボン系の冷媒は塩素成分がないため、冷凍機油として用いられる従来の鉱油とは相溶性がなく、アキュムレ−タ４内部で液冷媒と分離して、上部に浮かんでしまい、油戻し穴５から冷凍機油が圧縮機１へ戻らなくなる。したがって、アキュムレ−タに大量の液冷媒を溜め、かつ圧縮機１をモ−タで駆動する空気調和装置においては、ハイドロフルオロカ−ボン系の冷媒と相溶性があり、絶縁性に優れたポリエステル油またはポリエ−テル油が一般的に用いられる。
【０００６】
ところが、これらポリエステル油やポリエ−テル油は水分を吸湿して、圧縮機１の摺動部のような高温状態の許におかれると加水分解したり、酸素や冷媒回路構成品を加工する際に混入する加工油や洗浄剤の残成分により劣化するおそれがある。特に、ポリエ−テル油に使用される添加剤のうち摩耗防止剤は一般に活性度の高いエステル系のものでポリエ−テル油が加水分解しなくてもこの添加剤が加水分解し高温状態の圧縮機１の摺動部において熱劣化する。
【０００７】
その際に発生するこれら劣化生成物は冷凍機油中に固体として存在するものと、溶けこんで存在するものとがある。この固体成分と溶解成分のいずれも高温高圧のガス冷媒が圧縮機１から吐出されると、冷凍機油とともに吐出ガスに混ざって冷媒回路中に吐出される。上記冷凍機油の劣化生成物は冷媒とともに凝縮器（冷房時は熱源機側熱交換器３、暖房時は室内機側熱交換器７ｂ、７ｃ、７ｄ）へ流入し、冷媒はここで液化する。冷媒が液化して冷媒の濃度が高まると、冷媒とともに流れていた冷凍機油中に溶けこんでいた冷凍機油の劣化生成物は溶けこめなくなり、固体として析出するものと直接配管の管壁に析出するものが出現する。
【０００８】
これら新たに析出された劣化生成物は元から固体として存在していた劣化生成物とともに第１の絞り装置８ｂ、８ｃ、８ｄ、第２の絞り装置６へ流入する。冷媒回路構成品を加工する際に混入する加工油や洗浄剤の残成分の中のハイドロフルオロカ−ボン系の冷媒と相溶性の無いものが配管の管壁に皮膜を形成し、この非相溶成分がバインダ−となって、上記冷凍機油の劣化生成物が配管の管壁に付着する。特に、急に、流路断面積が変化する毛細管などの絞り装置では、流れに淀みができ、この冷凍機油の劣化生成物の付着が著しい。このようにして、冷凍機油中に固体として存在する冷凍機油劣化物はスラッジとして第１の絞り装置８ｂ、８ｃ、８ｄ及び第２の絞り装置６に付着する。また、アキュムレ−タ４内部に液冷媒が溜まっている場合、油戻し穴５にも絞り装置と同様に冷凍機油の固体もしくは溶解成分である劣化生成物が析出・付着する。
【０００９】
以上のようなスラッジ付着の対策として、合成ゼオライトなどを主成分とする乾燥剤を円筒容器や配管内に内蔵させたドライヤ１１，１２が切換弁２とアキュムレ−タ４との間の冷媒配管、及び第１の絞り装置８ｂ、８ｃ、８ｄと第２の絞り装置６との間の液側接続冷媒配管９に設けられ、そして、細かい網目状のフィルタを円筒容器や配管内に内蔵したスラッジフィルタが、熱源機側熱交換器３と第２の絞り装置６との間の冷媒配管、及び室内側熱交換器７ｂ、７ｃ、７ｄと第１の絞り装置８ｂ、８ｃ、８ｄとの間の冷媒配管に設けられる。
【００１０】
切換弁２とアキュムレ−タ４との間に設けられたドライヤ１１には、冷房時は室内機側熱交換器７ｂ、７ｃ、７ｄから、暖房時は熱源機側熱交換器３から切換弁２を経てガス冷媒が流入し、ガス冷媒中に含まれる水分が吸収される。第１の絞り装置８ｂ、８ｃ、８ｄと第２の絞り装置６との間の液側接続冷媒配管９に設けられたドライヤ１２には、冷房時は熱源機側熱交換器３から、ほとんど全開の第２の絞り装置６をへて、暖房時は室内機側熱交換器７ｂ、７ｃ、７ｄから、ほとんど全開の第１の絞り装置８ｂ、８ｃ、８ｄをへて、ともに少し減圧された液単相流の冷媒が流入する。従ってドライヤ１２内の圧力損失は小さくて流れが静かになり充分に水分が吸収される。
【００１１】
熱源機側熱交換器３と第２の絞り装置６との間の冷媒配管に設けられたスラッジフィルタ１３において、冷房時に熱源機側熱交換器３へ冷媒とともに流入した冷凍機油の劣化生成物と、この熱源機側熱交換器３での冷媒の液化及び流速の低下により析出・付着した冷凍機油中に溶けこんでいた劣化生成物とがスラッジとして捕捉される。また、室内側熱交換器７ｂ、７ｃ、７ｄと第１の絞り装置８ｂ、８ｃ、８ｄとの間の冷媒配管に設けられたスラッジフィルタ１４ｂ、１４ｃ、１４ｄにおいて、暖房時に室内側熱交換器７ｂ、７ｃ、７ｄへ冷媒とともに流入した冷凍機油の劣化生成物と、これら室内側熱交換器７ｂ、７ｃ、７ｄでの冷媒の液化及び流速の低下により析出・付着した冷凍機油中に溶けこんでいた劣化生成物とがスラッジとして捕捉される。
【００１２】
【発明が解決しようとする課題】
上記のようなドライヤを用いた従来の空気調和装置においては、ドライヤ１１を冷媒ガスが通過することで吸入圧力損失が発生し、蒸発能力が低下し、逆に蒸発能力の低下を抑えようとするとドライヤ１１を大形化する必要がある。また、冷媒配管の施工時に充分な無酸化ロウ付けを実施されていないと酸化スケ−ルが発生し、それが運転時にドライヤ１１，１２に流入し、流路が閉塞したり、ドライヤ１１が粉砕したりする危険性があった。さらに、圧縮機起動、冷暖房切換、デフロスト開始・終了などの過渡的な運転時に生ずる急激な液バックや、冷媒液の激しい流れによりドライヤ１１，１２が粉砕する危険性もあった。
【００１３】
また、上記のようなスラッジフィルタを設置した従来の空気調和装置においては、熱源機側熱交換器３と第２の絞り装置６との間及び室内側熱交換器７ｂ、７ｃ、７ｄと第１の絞り装置８ｂ、８ｃ、８ｄとの間の全ての位置にスラッジフィルタを設置する必要があり、空気調和装置全体が大形化するという問題点があった。また、冷房時に熱源機側熱交換器３と第２の絞り装置６との間のスラッジフィルタ１３で捕捉されたスラッジは、流れが暖房に切換わると剥離して、熱源機側熱交換器３及び切換弁２を経由してアキュムレ−タ４に流入し、油戻し穴５が閉塞される。同様に暖房時に室内側熱交換器７ｂ、７ｃ、７ｄと第１の絞り装置８ｂ、８ｃ、８ｄとの間のスラッジフィルタ１４ｂ、１４ｃ、１４ｄで捕捉したスラッジは、流れが冷房に切換わると剥離して、室内側熱交換器７ｂ、７ｃ、７ｄ及び切換弁２を経由してアキュムレ−タ４に流入し、油戻し穴５が閉塞される。さらに、冷媒配管の施工時に充分な無酸化ロウ付けを実施されていないと酸化スケ−ルが発生し、それが運転時にスラッジフィルタ１３，１４ｂ、１４ｃ、１４ｄに流入し、流路が閉塞したり、スラッジフィルタを傷めたりする危険性もあった。
【００１４】
この発明は上記のような問題点を解消するためになされたもので、ハイドロフルオロカ−ボン系の冷媒を作動流体とし、この冷媒と相溶性のある油を冷凍機油として用いても、冷凍機油の劣化生成物が生じにくく、例え劣化生成物が生じたとしても、これによる不具合のない信頼性の高い空気調和装置を得ることを目的としている。
【００１５】
【課題を解決するための手段】
【００２１】
請求項１に係るこの発明の空気調和装置は、圧縮機、凝縮器、絞り装置、蒸発器より構成された主冷媒回路を備え、ハイドロフルオロカ−ボン系の冷媒を作動媒体として用い、この冷媒と相溶性のある油を冷凍機油として用いる空気調和装置において、上記圧縮機吐出部に油分離器を設け、分離した冷凍機油を圧縮機吸入部に戻す返油バイパス回路と、上記返油バイパス回路途中に冷凍機油劣化物を補足するスラッジフィルタを設けたものである。
【００２３】
請求項２に係るこの発明の空気調和装置は、請求項１に記載の発明において、返油バイパス回路途中のスラッジフィルタ上流に冷凍機油を冷却するバイパス熱交換器を設けたものである。
【００２４】
請求項３に係るこの発明の空気調和装置は、請求項１に記載の発明において、返油バイパス回路途中のスラッジフィルタ上流に液冷媒を注入する液冷媒注入回路を設けたものである。
【００２５】
請求項４に係るこの発明の空気調和装置は、請求項１〜３の何れかに記載の発明において、返油バイパス途中のスラッジフィルタを、水分を吸収しかつスラッジフィルタ機能を有するドライヤとしたものである。
【００２７】
請求項５に係るこの発明の空気調和装置は、請求項２に記載の発明において、バイパス熱交換器の全部または一部として熱源機側熱交換器の最下部を通す構成としたものである。
【００３２】
【発明の実施の形態】
実施の形態１．
以下、この発明の実施の形態１を図１によって説明する。図１はこの実施の形態１にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、６は第２の絞り装置、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管で、以上は図２８に示す従来例と同様のものである。
【００３３】
１５は第２の絞り装置６と液側接続冷媒配管９との間から分岐し、他端が切換弁２と圧縮機１との間の冷媒配管に接続するバイパス回路、１６はバイパス回路１５の配管途中に設けられたドライヤ、１７はバイパス回路１５の配管途中のドライヤ１６の下流に設けられたバイパス絞り装置（以下第３の絞り装置という）、１８ａはバイパス回路１５の第３の絞り装置１７より下流の部分と、第２の絞り装置６と熱源機側熱交換器３との間の部分とが熱交換する第１のバイパス熱交換器、１８ｂはバイパス回路１５の第３の絞り装置１７より下流の部分と、第２の絞り装置６と液側接続冷媒配管９との間の部分とが熱交換する第２のバイパス熱交換器、１９はバイパス回路１５の配管途中の絞り装置１７より上流の部分に設けられた第１の温度検出手段、２０はバイパス回路１５の配管途中の絞り装置１７より下流でかつ第１、第２のバイパス熱交換器１８ａ、１８ｂの上流の部分に設けられた第２の温度検出手段、２１は切換弁２と圧縮機１との間の部分に設けられた吸入圧力検出手段である。
【００３４】
次に、冷媒の流れを図によって説明する。まず、冷房時においては、圧縮機１で高温高圧まで圧縮されたガス冷媒は切換弁２を経て熱源機側熱交換器３に流入し、空気などと熱交換して凝縮し、高温高圧の液冷媒となる。さらに、冷房時全開の第２の絞り装置６、液側接続冷媒配管９をへて、室内機Ｂ、Ｃ、Ｄに達し、室内機側熱交換器７ｂ、７ｃ、７ｄの出口の過熱度が一定範囲になるように制御される第１の絞り装置８ｂ、８ｃ、８ｄによって、低圧の気液ニ相状態まで絞られる。低圧の気液ニ相冷媒は室内機側熱交換器７ｂ、７ｃ、７ｄに流入して、室内の空気と熱交換してガス化し、ガス側接続冷媒配管１０、切換弁２、アキュムレ−タ４を経て圧縮機１へ戻る。アキュムレ−タ４内部の冷凍機油は液冷媒とともに油戻し穴５より圧縮機１へ戻る。
【００３５】
また、熱源機側熱交換器３から全開状態の第２の絞り装置６を通過した液冷媒一部がバイパス回路１５に流入する。バイパス回路１５ではドライヤ１６を経て、第３の絞り装置１７で低圧まで減圧され低温低圧の気液ニ相冷媒となる。この低温低圧の気液ニ相冷媒は、バイパス熱交換器１８ａ、１８ｂで、熱源機側熱交換器３を出た高温高圧の液冷媒と、また第２の絞り装置６を出た高温高圧の液冷媒と熱交換し、ガス化して、切換弁２と圧縮機１との間で、室内機Ｂ、Ｃ、Ｄを経た冷媒と合流し、圧縮機１へ戻る。一方、熱源機側熱交換器３を出た液冷媒は第１のバイパス熱交換器１８ａで冷却され、バイパス回路１５に流入する液冷媒は熱源機側熱交換器３を出た液冷媒より温度が低下する。また、その冷媒は更に第２の絞り装置６を経て、第２のバイパス熱交換器１８ｂで冷却され、液側接続冷媒配管９に流入する液冷媒は充分に過冷却が取られる。よって、液側接続冷媒配管９の長さが長く、ここを流れる間に冷媒の圧力降下が大きくても、また室内機Ｂ、Ｃ，、Ｄが熱源機Ａより上に設置され液側接続冷媒配管内の液冷媒の重力の影響が大きくても、第１の絞り装置８ａ、８ｂ、８ｃに流入する冷媒は液状態を確保することができ、安定した運転が可能である。
【００３６】
暖房時においては、圧縮機１で高温高圧まで圧縮されたガス冷媒は切換弁２、ガス側接続冷媒配管１０を経て、室内機Ｂ、Ｃ、Ｄに達し、室内機側熱交換器７ｂ、７ｃ、７ｄに流入し、室内の空気と熱交換して凝縮し、高温高圧の液冷媒となる。室内側熱交換器７ｂ、７ｃ、７ｄを出た液冷媒は暖房時殆ど全開の第１の絞り装置７ｂ、７ｃ、７ｄで少し減圧して、液側接続冷媒配管９をへて第２の絞り装置６に達し、ここで低圧の気液ニ相状態まで絞られる。低圧の気液ニ相冷媒は熱源機側熱交換器３に流入し、空気などと熱交換してガス化し、切換弁２、アキュムレ−タ４を経て圧縮機１へ戻る。アキュムレ−タ４内部の冷凍機油は液冷媒とともに油戻し穴５より圧縮機１へ戻る。
【００３７】
また、室内機側熱交換器７ｂ、７ｃ、７ｄから全開状態の第１の絞り装置８ａ、８ｂ、８ｃ、液側接続冷媒配管９を通過した液冷媒の一部がバイパス回路１５に流入する。バイパス回路１５ではドライヤ１６を経て、第３の絞り装置１７で低圧まで減圧され低温低圧の気液ニ相冷媒となる。この低温低圧の気液ニ相冷媒は、バイパス熱交換器１８ｂで液側接続冷媒配管９を出た高温高圧の液冷媒と、バイパス熱交換器１８ａで第２の絞り装置６で絞られた低圧の気液ニ相冷媒と熱交換し、ガス化して、切換弁２と圧縮機１との間で、熱源機側熱交換器３を経た冷媒と合流し、圧縮機１へ戻る。一方、液側接続冷媒配管９を出た液冷媒は第２のバイパス熱交換器１８ｂで冷却され、バイパス回路１５に流入する液冷媒は液側接続冷媒配管９を出た液冷媒より温度が低下し、第２の絞り装置６に流入する冷媒は液状態を確保することができ、安定した運転が可能である。
【００３８】
次に、ドライヤ１６の作用について説明する。圧縮機１を吐出した冷媒・冷凍機油中に含まれる水分は、飽和上限以下であればバイパス回路１５の起点に達するまで変化しない。この点から冷房時には室内側熱交換器７ｂ、７ｃ、７ｄを、暖房時には熱源機側熱交換器３を経由して、切換弁２をへてバイパス回路１５との合流点にいたる主冷媒回路では、それ以後も冷媒・冷凍機油中に含まれる水分は変化しない。一方、バイパス回路１５では、冷媒・冷凍機油がドライヤ１６に流入するとそこで吸湿され、ドライヤ１６の下流では冷媒・冷凍機油中の水分量は低下する。切換弁２と圧縮機１との間のバイパス回路１５を流れる冷媒・冷凍機油と主冷媒回路を流れる冷媒・冷凍機油とが合流する点で、それまで主冷媒回路を流れる冷媒・冷凍機油中に含まれていた水分とバイパス回路１５を流れる冷媒・冷凍機油中に含まれていた水分とが混合し、主冷媒回路を流れる冷媒・冷凍機油中に含まれていた水分量よりも合流後の水分量はその濃度では低下する。即ち、バイパス回路１５にあるドライヤ１６により水分は吸収され冷媒回路中の含有水分量は低下する。
【００３９】
この実施の形態では、主冷媒回路中にドライヤを設ける場合と比べて水分吸着速度は遅くなるが、ポリエステル油の加水分解劣化の速度も遅いので、バイパス回路１５の配管途中にあるドライヤ１６の水分吸着能力により加水分解は充分抑制され、圧縮機１でのスラッジ成分生成を抑制することができる。また、ドライヤ１６をバイパス回路１５の配管途中に設けることでドライヤ１６を流れる冷媒流れの衝撃を低下させることができ、ドライヤ１６が粉砕しにくくなる。さらに、第１、第２のバイパス熱交換器１８ａ、１８ｂによりドライヤ１６に流入する冷媒を冷却するため、圧縮機１の起動時やデフロストなどの過渡的な運転時にあっても、ドライヤ１６に流入する冷媒を液状態としやすく、ドライヤ１６がさらに粉砕しにくくなる。また、冷媒は温度が低いと冷媒への水分飽和溶解度が低く、ドライヤとの共存下では、相対的に冷媒中よりもドライヤに水分は移動しやすく、ドライヤの水分吸着能力は高くなる。よって、ドライヤ１６に流入する冷媒の温度が低くなると、それだけドライヤ１６の水分吸着量が増え、冷凍機油の加水分解を抑えることができる。
【００４０】
実施の形態２．
以下、この発明の実施の形態２を図２によって説明する。図２はこの実施の形態２にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、６は第２の絞り装置、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管で、以上は図２８に示す従来例と同様のものである。
【００４１】
１５は第２の絞り装置６と液側接続冷媒配管９との間から分岐し、他端が切換弁２と圧縮機１との間の冷媒配管に接続するバイパス回路、１６はバイパス回路１５の配管途中に設けられたドライヤ、１７はバイパス回路１５の配管途中のドライヤ１６の下流に設けられた第３の絞り装置、１８はバイパス回路１５のドライヤ１６より上流の部分と切換弁２とアキュムレ−タ４との間の部分とが熱交換するバイパス熱交換器、１９はバイパス回路１５の配管途中の絞り装置１７より上流の部分に設けられた第１の温度検出手段、２０はバイパス回路１５の配管途中の絞り装置１７より下流に設けられた第２の温度検出手段、２１は切換弁２と圧縮機１との間の部分に設けられた吸入圧力検出手段である。
【００４２】
次に、冷媒の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第２の絞り装置６、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れは実施の形態１と全く同様なので説明を省略し、バイパス回路１５における冷媒の流れを説明する。
【００４３】
冷房時に熱源機側熱交換器３から全開状態の第２の絞り装置６を通過し、暖房時に室内機側熱交換器７ｂ、７ｃ、７ｄから全開状態の第１の絞り装置８ａ、８ｂ、８ｃ、液側接続冷媒配管９を通過した液冷媒一部がバイパス回路１５に流入する。バイパス回路１５に流入した液冷媒は、バイパス熱交換器１８で切換弁２を経た低温低圧の冷媒と熱交換して温度が低下し、ドライヤ１６を経て、第３の絞り装置１７で低圧まで減圧され低温低圧の気液ニ相冷媒となる。この低温低圧の気液ニ相冷媒は切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流し、アキュムレータ４で気液分離して圧縮機１へ戻る。
【００４４】
次に、ドライヤ１６の作用について説明する。圧縮機１を吐出した冷媒・冷凍機油中に含まれる水分は、飽和上限以下であればバイパス回路１５の起点に達するまで変化しない。この点から冷房時には室内側熱交換器７ｂ、７ｃ、７ｄを、暖房時には熱源機側熱交換器３を経由して、切換弁２をへてバイパス回路１５との合流点にいたる主冷媒回路では、それ以後も冷媒・冷凍機油中に含まれる水分は変化しない。一方、バイパス回路１５では、冷媒・冷凍機油がドライヤ１６に流入するとそこで吸湿され、ドライヤ１６の下流では冷媒・冷凍機油中の水分量は低下する。切換弁２と圧縮機１との間のバイパス回路１５を流れる冷媒・冷凍機油と主冷媒回路を流れる冷媒・冷凍機油とが合流する点で、それまで主冷媒回路を流れる冷媒・冷凍機油中に含まれていた水分とバイパス回路１５を流れる冷媒・冷凍機油中に含まれていた水分とが混合し、主冷媒回路を流れる冷媒・冷凍機油中に含まれていた水分量よりも合流後の水分量はその濃度では低下する。即ち、バイパス回路１５にあるドライヤ１６により水分は吸収され冷媒回路中の含有水分量は低下する。
【００４５】
この実施の形態でも、主冷媒回路中にドライヤを設ける場合と比べて水分吸着速度は遅くなるが、ポリエステル油の加水分解劣化の速度も遅いので、バイパス回路１５の配管途中にあるドライヤ１６の水分吸着能力により加水分解は充分抑制され、圧縮機１でのスラッジ成分生成を抑制することができる。また、ドライヤ１６をバイパス回路１５の配管途中に設けることでドライヤ１６を流れる冷媒流れの衝撃を低下させることができ、ドライヤ１６が粉砕しにくくなる。さらに、バイパス熱交換器１８によりドライヤ１６に流入する冷媒を冷却するため、圧縮機１の起動時やデフロストなどの過渡的な運転時にあっても、ドライヤ１６に流入する冷媒を液状態としやすく、ドライヤ１６がさらに粉砕しにくくなる。また、冷媒は温度が低いと冷媒への水分飽和溶解度が低く、ドライヤとの共存下では、相対的に冷媒中よりもドライヤに水分は移動しやすく、ドライヤの水分吸着能力は高くなる。よって、ドライヤ１６に流入する冷媒の温度が低くなると、それだけドライヤ１６の水分吸着量が増え、冷凍機油の加水分解を抑えることができる。
【００４６】
実施の形態３．
以下、この発明の実施の形態３を図３によって説明する。図３はこの実施の形態３にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、６は第２の絞り装置、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管で、以上は図２８に示す従来例と同様のものである。
【００４７】
１５は第２の絞り装置６と液側接続冷媒配管９との間から分岐し、他端が切換弁２と圧縮機１との間の冷媒配管に接続するバイパス回路、１６はバイパス回路１５の配管途中に設けられたドライヤ、１７はバイパス回路１５の配管途中のドライヤ１６の下流に設けられた第３の絞り装置、１８は、バイパス回路１５のドライヤ１６より上流の部分と熱源機側熱交換器３の最も下の部分に流入する空気の一部とが熱交換するバイパス熱交換器、１９はバイパス回路１５の配管途中の絞り装置１７より上流の部分に設けられた第１の温度検出手段、２０はバイパス回路１５の配管途中の絞り装置１７より下流に設けられた第２の温度検出手段、２１は切換弁２と圧縮機１との間の部分に設けられた吸入圧力検出手段である。
【００４８】
次に、冷媒の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第２の絞り装置６、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れは実施の形態１と全く同様なので説明を省略し、バイパス回路１５における冷媒の流れを説明する。
【００４９】
冷房時に熱源機側熱交換器３から全開状態の第２の絞り装置６を通過し、暖房時に室内機側熱交換器７ｂ、７ｃ、７ｄから全開状態の第１の絞り装置８ａ、８ｂ、８ｃ、液側接続冷媒配管９を通過した液冷媒一部がバイパス回路１５に流入する。バイパス回路１５に流入した液冷媒は、バイパス熱交換器１８で熱源機側熱交換器３の最下部に流入する空気の一部と熱交換して温度が低下し、ドライヤ１６を経て、第３の絞り装置１７で低圧まで減圧され低温低圧の気液ニ相冷媒となる。この低温低圧の気液ニ相冷媒は切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流し、アキュムレータ４で気液分離して圧縮機１へ戻る。
なお、暖房時において蒸発器となる、バイパス熱交換器１８が設けられる熱源機側熱交換器３の最下部においては、上部からのドレンの流れで風が通りにくく霜が発生し成長しやすいが、バイパス熱交換器１８により暖められ、着霜しにくくなる。
【００５０】
この実施の形態３においても、バイパス回路１５中に水分を吸収するドライヤ１６が設けられ、それに流入する冷媒がバイパス熱交換器１８により冷されるので、実施の形態１，２と同様に冷媒回路中の含有水分量は低下し、冷凍機油の加水分解を抑えることができるとともに、冷媒流によるドライヤ１６の粉砕が防止できる。
【００５１】
実施の形態４．
以下、この発明の実施の形態４を図４によって説明する。図４はこの実施の形態４にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、６は第２の絞り装置、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管で、以上は図２８に示す従来例と同様のものである。
【００５２】
１５は圧縮機１の吐出部と切換弁２との間から分岐し、他端が切換弁２と圧縮機１との間の冷媒配管に接続するバイパス回路、１６はバイパス回路１５の配管途中に設けられたドライヤ、１７はバイパス回路１５の配管途中のドライヤ１６の下流に設けられた第３の絞り装置、１８は、バイパス回路１５のドライヤ１６より上流の部分とバイパス回路１５の第３の絞り装置１７より下流の部分とが熱交換するバイパス熱交換器、１９はバイパス回路１５の配管途中の絞り装置１７より上流の部分に設けられた第１の温度検出手段、２０はバイパス回路１５の配管途中の絞り装置１７より下流に設けられた第２の温度検出手段、２１は切換弁２と圧縮機１との間の部分に設けられた第２の圧力検出手段である。
【００５３】
次に、冷媒の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第２の絞り装置６、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れは実施の形態１と全く同様なので説明を省略し、バイパス回路１５における冷媒の流れを説明する。
【００５４】
冷房時、暖房時何れの場合においても、圧縮機１を吐出された高温・高圧のガス冷媒の一部がバイパス回路１５に流入する。バイパス回路１５に流入した高温・高圧のガス冷媒は、バイパス熱交換器１８で下流の低圧側の冷媒と熱交換して温度が低下して液化し、ドライヤ１６を経て、第３の絞り装置１７で低圧まで減圧され低温低圧の気液ニ相冷媒となり、バイパス熱交換器１８で高圧側の冷媒と熱交換してガス化する。この低温低圧のガス冷媒は切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流し、アキュムレータ４で気液分離して圧縮機１へ戻る。
【００５５】
この実施の形態４においても、バイパス回路１５中に水分を吸収するドライヤ１６が設けられ、それに流入する冷媒がバイパス熱交換器１８により冷されるので、実施の形態１，２及び３と同様に冷媒回路中の含有水分量は低下し、冷凍機油の加水分解を抑えることができるとともに、冷媒流によるドライヤ１６の粉砕が防止できる。
また、この実施の形態４では、圧縮機１からバイパス回路１５をへて圧縮機１に戻るサイクルが非常に短いため、応答性がよく、ドライヤに液が供給されない過渡的な状態となる時間が非常に短く、ドライヤ１６が粉砕しにくい。さらに、このサイクルには液側接続冷媒配管９やガス側接続冷媒配管１０が含まれないので、これら配管９，１０の施工時に充分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルがバイパス回路１５中のドライヤ１６に流入することがなく、それにより流路を閉塞したり、ドライヤを粉砕したりする危険性もなくなる。
【００５６】
実施の形態５．
以下、この発明の実施の形態５を図５によって説明する。図５はこの実施の形態５にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、６は第２の絞り装置、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管で、以上は図２８に示す従来例と同様のものである。
【００５７】
１５は圧縮機１と切換弁２との間から分岐し、他端が切換弁２と圧縮機１との間の冷媒配管に接続するバイパス回路、１６はバイパス回路１５の配管途中に設けられたドライヤ、１７はバイパス回路１５の配管途中のドライヤ１６の下流に設けられた第３の絞り装置、１８は、バイパス回路１５のドライヤ１６より上流の部分と熱源機側熱交換器３の最も下の部分に流入する空気の一部とが熱交換するバイパス熱交換器、１９はバイパス回路１５の配管途中の絞り装置１７より上流の部分に設けられた第１の温度検出手段、２０はバイパス回路１５の配管途中の絞り装置１７より下流に設けられた第２の温度検出手段、２１は切換弁２と圧縮機１との間の部分に設けられた第２の圧力検出手段である。
【００５８】
次に、冷媒の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第２の絞り装置６、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れは実施の形態１と全く同様なので説明を省略し、バイパス回路１５における冷媒の流れを説明する。
【００５９】
冷房時、暖房時何れの場合においても、圧縮機１を吐出された高温・高圧のガス冷媒の一部がバイパス回路１５に流入する。バイパス回路１５に流入した高温・高圧のガス冷媒は、バイパス熱交換器１８で熱源機側熱交換器３の最下部に流入する空気の一部と熱交換して温度が低下して液化し、ドライヤ１６を経て、第３の絞り装置１７で低圧まで減圧されて切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流し、アキュムレータ４で気液分離して圧縮機１へ戻る。
なお、この実施の形態５でも実施の形態３と同様、暖房時において蒸発器となる、バイパス熱交換器１８が設けられる熱源機側熱交換器３の最下部においては、上部からのドレンの流れで風が通りにくく霜が発生し成長しやすいが、バイパス熱交換器１８により暖められ、着霜しにくくなる。
【００６０】
この実施の形態５においても、バイパス回路１５中に水分を吸収するドライヤ１６が設けられ、それに流入する冷媒がバイパス熱交換器１８により冷されるので、実施の形態１〜４と同様に冷媒回路中の含有水分量は低下し、冷凍機油の加水分解を抑えることができるとともに、冷媒流によるドライヤ１６の粉砕が防止できる。
また、実施の形態４と同様、圧縮機１からバイパス回路１５をへて圧縮機１に戻るサイクルが非常に短いため、応答性がよく、ドライヤに液が供給されない過渡的な状態となる時間が非常に短く、ドライヤ１６が粉砕しにくい。さらに、このサイクルには液側接続冷媒配管９やガス側接続冷媒配管１０が含まれないので、これら配管９，１０の施工時に充分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルがバイパス回路１５中のドライヤ１６に流入することがなく、それにより流路を閉塞したり、ドライヤを粉砕したりする危険性もなくなる。
【００６１】
実施の形態６．
以下、この発明の実施の形態６を図６によって説明する。図６はこの実施の形態６にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、６は第２の絞り装置、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管で、以上は図２８に示す従来例と同様のものである。
【００６２】
１５は圧縮機１と切換弁２との間から分岐し、他端が切換弁２と圧縮機１との間の冷媒配管に接続するバイパス回路、１６はバイパス回路１５の配管途中に設けられたドライヤ、１７はバイパス回路１５の配管途中のドライヤ１６の下流に設けられた第３の絞り装置、１８ａは、バイパス回路１５のドライヤ１６より上流の部分と熱源機側熱交換器３の最も下の部分に流入する空気の一部とが熱交換する第１のバイパス熱交換器、１８ｂは、バイパス回路１５の第１のバイパス熱交換器１８ａとドライヤ１６との間の部分と、第３の絞り装置１７より下流の部分とが熱交換する第２のバイパス熱交換器、１９はバイパス回路１５の配管途中の絞り装置１７より上流の部分に設けられた第１の温度検出手段、２０はバイパス回路１５の配管途中の絞り装置１７より下流に設けられた第２の温度検出手段、２１は切換弁２と圧縮機１との間の部分に設けられた第２の圧力検出手段である。
【００６３】
次に、冷媒の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第２の絞り装置６、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れは実施の形態１と全く同様なので説明を省略し、バイパス回路１５における冷媒の流れを説明する。
【００６４】
冷房時、暖房時何れの場合においても、圧縮機１を吐出された高温・高圧のガス冷媒の一部がバイパス回路１５に流入する。バイパス回路１５に流入した高温・高圧のガス冷媒は、第１のバイパス熱交換器１８ａで熱源機側熱交換器３の最下部に流入する空気の一部と熱交換して温度が低下して液化し、第２のバイパス熱交換器１８ｂで下流の低圧側の冷媒と熱交換して冷媒の温度がさらに低下する。その後、ドライヤ１６を経て、第３の絞り装置１７で低圧まで減圧され低温低圧の気液ニ相冷媒となり、バイパス熱交換器１８で高圧側の冷媒と熱交換してガス化し、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流し、アキュムレータ４で気液分離して圧縮機１へ戻る。
なお、この実施の形態６でも実施の形態３と同様、暖房時において蒸発器となる、第１のバイパス熱交換器１８ａが設けられる熱源機側熱交換器３の最下部においては、上部からのドレンの流れで風が通りにくく霜が発生し成長しやすいが、バイパス熱交換器１８により暖められ、着霜しにくくなる。
【００６５】
この実施の形態６においても、バイパス回路１５中に水分を吸収するドライヤ１６が設けられ、それに流入する冷媒がバイパス熱交換器１８ａ，１８ｂにより冷されるので、実施の形態１〜５と同様に冷媒回路中の含有水分量は低下し、冷凍機油の加水分解を抑えることができるとともに、冷媒流によるドライヤ１６の粉砕が防止できる。
また、実施の形態４，５と同様、圧縮機１からバイパス回路１５をへて圧縮機１に戻るサイクルが非常に短いため、応答性がよく、ドライヤに液が供給されない過渡的な状態となる時間が非常に短く、ドライヤ１６が粉砕しにくい。さらに、このサイクルには液側接続冷媒配管９やガス側接続冷媒配管１０が含まれないので、これら配管９，１０の施工時に充分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルがバイパス回路１５中のドライヤ１６に流入することがなく、それにより流路を閉塞したり、ドライヤを粉砕したりする危険性もなくなる。
【００６６】
実施の形態７．
以下、この発明の実施の形態７を図１、図７及び図８によって説明する。図１はこの実施の形態７にかかる空気調和装置の冷媒回路図、図７はこの実施の形態７にかかる空気調和装置の組成演算に関するブロック線図、図８はその組成演算手段の動作を示すフロ−チャ−トである。なお、図２〜図６はバイパス回路１５の位置・構成・冷媒の流れが異なるが、図１と同様この実施の形態７が適用される。また、この実施の形態における作動媒体としてハイドロフルオロカ−ボン系の混合冷媒を用いるものである。
【００６７】
図において、１９はバイパス回路１５の配管途中の絞り装置１７より上流の部分に設けられ、第３の絞り装置１７の入口の高温高圧の液冷媒の温度を検出する第１の温度検出手段、２０はバイパス回路１５の配管途中の絞り装置１７より下流でかつ第１、第２のバイパス熱交換器１８ａ、１８ｂの上流の部分に設けられ、第３の絞り装置１７の出口の低温低圧の気液二相冷媒の温度を検出する第２の温度検出手段、２１は切換弁２と圧縮機１との間の部分に設けられた第２の圧力検出手段、２２は、第１の温度検出手段１９、第２の温度検出手段２０、及び第２の圧力検出手段２１の検出値に基づいて、混合冷媒の組成を演算する組成演算手段である。
【００６８】
次にその組成演算動作を図８によって説明する。まず、ステップ１００で、混合冷媒の各成分について、その組成Ｘｉが仮定される。ステップ１０１では、第１の温度検出手段１９、第２の温度検出手段２０、吸入圧力検出手段２１から各々の検出値Ｔ１、Ｔ２、Ｐ２が検出される。ステップ１０２では、ステップ１００で仮定した循環組成Ｘｉと上記第１の温度検出手段１９の検出値Ｔ１から、高圧の液エンタルピＨ１が演算される。ステップ１０３では、循環組成Ｘｉと上記第２の温度検出手段２０の検出値Ｔ２及び吸入圧力検出手段２１の検出値Ｐ２から、低圧の二相エンタルピＨ２が演算される。ステップ１０４では、上記Ｈ１とＨ２の比較が行われ、等しくなるまで循環組成の仮定が繰り返される。この結果、上記Ｈ１とＨ２が等しくなった時点でのＸｉの値が循環組成として算出される。ここで、添字ｉは、ｉ種の成分が混合された冷媒であることを示している。
【００６９】
実施の形態８．
以下、この発明の実施の形態８を図９によって説明する。図９はこの実施の形態８にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管で、以上は図２８に示す従来例と同様のものである。２３は圧縮機１の吐出部と切換弁２との間に設けられ、圧縮機１から冷媒と共に吐出された冷凍機油をガス冷媒から分離する油分離器、２４は油分離器２３の底部と切換弁２、圧縮機１の吸入部間を接続する、分離された冷凍機油を圧縮機１の吸入部に戻す返油バイパス回路、２５は返油バイパス回路２４の配管途中に設けられた第４の絞り装置である。
【００７０】
次に、冷媒の流れを図によって説明する。まず、冷房時においては、圧縮機１で高温高圧まで圧縮されたガス冷媒は切換弁２を経て熱源機側熱交換器３に流入し、空気などと熱交換して凝縮し、高温高圧の液冷媒となる。さらに、液側接続冷媒配管９をへて、室内機Ｂ、Ｃ、Ｄに達し、室内機側熱交換器７ｂ、７ｃ、７ｄの出口の過熱度が一定範囲になるように制御される第１の絞り装置８ｂ、８ｃ、８ｄによって、低圧の気液ニ相状態まで絞られる。低圧の気液ニ相冷媒は室内機側熱交換器７ｂ、７ｃ、７ｄに流入して、室内の空気と熱交換してガス化し、ガス側接続冷媒配管１０、切換弁２、アキュムレ−タ４を経て圧縮機１へ戻る。アキュムレ−タ４内部の冷凍機油は液冷媒とともに油戻し穴５より圧縮機１へ戻る。
【００７１】
暖房時においては、圧縮機１で高温高圧まで圧縮されたガス冷媒は切換弁２、ガス側接続冷媒配管１０を経て、室内機Ｂ、Ｃ、Ｄに達し、室内機側熱交換器７ｂ、７ｃ、７ｄに流入し、室内の空気と熱交換して凝縮し、高温高圧の液冷媒となる。室内側熱交換器７ｂ、７ｃ、７ｄを出た液冷媒は第１の絞り装置８ｂ、８ｃ、８ｄで低圧の気液ニ相状態まで絞られ、この低圧の気液ニ相冷媒は液側接続冷媒配管９をへて熱源機側熱交換器３に流入し、空気などと熱交換してガス化し、切換弁２、アキュムレ−タ４を経て圧縮機１へ戻る。アキュムレ−タ４内部の冷凍機油は液冷媒とともに油戻し穴５より圧縮機１へ戻る。
【００７２】
冷房時、暖房時何れの場合においても、圧縮機１に吸入された低温低圧のガス冷媒は圧縮されて高温高圧のガス冷媒となり圧縮機１より吐出される。この時、圧縮機１内部にある冷凍機油も一部吐出され、ガス冷媒とともに油分離器２３に流入し、ここでガス冷媒と分離される。油分離器２３により分離されたガス冷媒は切換弁２へ流れ、冷凍機油は返油バイパス回路２４に流入する。返油バイパス回路２４に流入した冷凍機油は第４の絞り装置２５で低圧まで減圧されて、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流する。このように圧縮機１の吐出部で冷凍機油を分離するので、主冷媒回路中の冷凍機油の循環流量比率は非常に低く、室内機Ｂ、Ｃ、Ｄ内にある第１の絞り装置８ｂ、８ｃ、８ｄを流れる冷凍機油の流量は著しく低下する。
【００７３】
また、圧縮機１の摺動部で生成される冷凍機油劣化物は、冷凍機油中に固体として存在するか、溶け込んで存在する。これらは、冷媒が圧縮機１から吐出されると冷凍機油と共に吐出ガスに混ざって吐出されるが油分離器２３により分離されて主冷媒回路中には流入されないので、室内機Ｂ、Ｃ、Ｄ内にある第１の絞り装置８ｂ、８ｃ、８ｄを流れる冷凍機油の流量は著しく低下し、冷凍機油と共に循環する冷凍機油劣化物の積算流量も低下する。これにより、冷凍機油劣化物がスラッジとなって第１の絞り装置８ｂ、８ｃ、８ｄに付着する量が減少し、それによる第１の絞り装置８ｂ、８ｃ、８ｄの流量不足が回避でき、空調能力の不足はなくなり、信頼性が著しく向上する。
【００７４】
実施の形態９．
以下、この発明の実施の形態９を図１０によって説明する。図１０はこの実施の形態９にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管、２３は油分離器、２４は返油バイパス回路、２５は第４の絞り装置で、以上は図９に示した実施の形態８と同様のものである。２６は返油バイパス回路２４の配管途中の第４の絞り装置２５の上流部に設けられたスラッジフィルタである。
【００７５】
次に、冷媒及び冷凍機油の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れ、及び油分離器２３の動作は実施の形態８と全く同様なので説明を省略し、返油バイパス回路２４における冷凍機油の流れを説明する。油分離器２３で分離された冷凍機油は返油バイパス回路２４に流入し、スラッジフィルタ２６を経て、第４の絞り装置２５で低圧まで減圧されて、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流する。
【００７６】
また、圧縮機１の摺動部で生成される冷凍機油劣化物は、冷凍機油とともに吐出ガスに混ざって冷媒回路中に吐出され、油分離器２３で冷凍機油とともに分離され、返油バイパス回路２４においてスラッジフィルタ２６で捕捉される。したがって、アキュムレータ４に流入し、圧縮機１に戻る冷凍機油中の冷凍機油劣化物含有率は低下し、油戻し穴５に付着するスラッジの量は低下する。それにより、圧縮機１内部の冷凍機油が枯渇することがなくなり、異常な高圧上昇・低圧低下・それによる吐出ガス温度上昇も回避でき、信頼性が著しく向上する。また、圧縮機１から吐出された冷媒などが返油バイパス回路２４を経て圧縮機１へ戻るサイクルは途中で液側接続冷媒配管９、ガス側接続冷媒配管１０を経由しない。したがって、液側接続冷媒配管９やガス側接続冷媒配管１０の施工時に十分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルが運転中にスラッジフィルタ２６に流入することがなく、流路を閉塞したり、スラッジフィルタを変形・破壊したりする危険性がない。
【００７７】
実施の形態１０．
以下、この発明の実施の形態１０を図１１によって説明する。図１１はこの実施の形態１０にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管、２３は油分離器、２４は返油バイパス回路、２５は第４の絞り装置、２６はスラッジフィルタで、以上は図１０に示した実施の形態９と同様のものである。２７は、返油バイパス回路２４のスラッジフィルタ２６より上流の部分と熱源機側熱交換器３の最も下の部分に流入する空気の一部とが熱交換するバイパス熱交換器である。
【００７８】
次に、冷媒及び冷凍機油の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れ、及び油分離器２３の動作は実施の形態８と全く同様なので説明を省略し、返油バイパス回路２４における冷凍機油の流れを説明する。油分離器２３で分離された冷凍機油は返油バイパス回路２４に流入し、バイパス熱交換器２７で熱源機側熱交換器３の最下部に流入する空気の一部と熱交換して温度が低下して、スラッジフィルタ２６を経て、第４の絞り装置２５で低圧まで減圧されて、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流する。
なお、この実施の形態１０でも実施の形態３，５及び６と同様、暖房時において蒸発器となる、バイパス熱交換器１８が設けられる熱源機側熱交換器３の最下部においては、上部からのドレンの流れで風が通りにくく霜が発生し成長しやすいが、バイパス熱交換器１８により暖められ、着霜しにくくなる。
【００７９】
また、圧縮機１の摺動部で生成される冷凍機油劣化物は、冷凍機油とともに吐出ガスに混ざって冷媒回路中に吐出され、油分離器２３で冷凍機油とともに分離され、返油バイパス回路２４においてスラッジフィルタ２６で捕捉される。しかも、バイパス熱交換器２７を通過することで、冷凍機油の温度が低下し、冷凍機油中の冷媒の濃度が高まる。これにより、冷凍機油中に溶け込んでいた冷凍機油劣化物が析出され、スラッジフィルタ２６では元々冷凍機油に溶け込んでいたものをも捕捉することができる。したがって、アキュムレータ４に流入し、圧縮機１に戻る冷凍機油中の冷凍機油劣化物含有率はさらに低下し、油戻し穴５に付着するスラッジの量は低下する。それにより、圧縮機１内部の冷凍機油が枯渇することがなくなり、異常な高圧上昇・低圧低下・それによる吐出ガス温度上昇も回避でき、信頼性が著しく向上する。また、圧縮機１から吐出された冷媒などが返油バイパス回路２４を経て圧縮機１へ戻るサイクルは途中で液側接続冷媒配管９、ガス側接続冷媒配管１０を経由しない。したがって、液側接続冷媒配管９やガス
側接続冷媒配管１０の施工時に十分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルが運転中にスラッジフィルタ２６に流入することがなく、流路を閉塞したり、スラッジフィルタを変形・破壊したりする危険性がない。
【００８０】
実施の形態１１．
以下、この発明の実施の形態１１を図１２によって説明する。図１２はこの実施の形態１１にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管、２３は油分離器、２４は返油バイパス回路、２５は第４の絞り装置、２６はスラッジフィルタで、以上は図１０に示した実施の形態９と同様のものである。２７は、返油バイパス回路２４のスラッジフィルタ２６より上流の部分と切換弁２とアキュムレ−タ４との間の部分とが熱交換するバイパス熱交換器である。
【００８１】
次に、冷媒及び冷凍機油の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れ、及び油分離器２３の動作は実施の形態８と全く同様なので説明を省略し、返油バイパス回路２４における冷凍機油の流れを説明する。油分離器２３で分離された冷凍機油は返油バイパス回路２４に流入し、バイパス熱交換器２７で切換弁２を経て圧縮機１へ戻る低温低圧の冷媒と熱交換して温度が低下して、スラッジフィルタ２６を経て、第４の絞り装置２５で低圧まで減圧されて、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流する。
【００８２】
また、圧縮機１の摺動部で生成される冷凍機油劣化物は、冷凍機油とともに吐出ガスに混ざって冷媒回路中に吐出され、油分離器２３で冷凍機油とともに分離され、返油バイパス回路２４においてスラッジフィルタ２６で捕捉される。しかも、バイパス熱交換器２７を通過することで、冷凍機油の温度が低下し、冷凍機油中の冷媒の濃度が高まる。これにより、冷凍機油中に溶け込んでいた冷凍機油劣化物が析出され、スラッジフィルタ２６では元々冷凍機油に溶け込んでいたものをも捕捉することができる。したがって、アキュムレータ４に流入し、圧縮機１に戻る冷凍機油中の冷凍機油劣化物含有率はさらに低下し、油戻し穴５に付着するスラッジの量は低下する。それにより、圧縮機１内部の冷凍機油が枯渇することがなくなり、異常な高圧上昇・低圧低下・それによる吐出ガス温度上昇も回避でき、信頼性が著しく向上する。また、圧縮機１から吐出された冷媒などが返油バイパス回路２４を経て圧縮機１へ戻るサイクルは途中で液側接続冷媒配管９、ガス側接続冷媒配管１０を経由しない。したがって、液側接続冷媒配管９やガス側接続冷媒配管１０の施工時に十分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルが運転中にスラッジフィルタ２６に流入することがなく、流路を閉塞したり、スラッジフィルタを変形・破壊したりする危険性がない。
【００８３】
実施の形態１２．
以下、この発明の実施の形態１２を図１３によって説明する。図１３はこの実施の形態１２にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管、２３は油分離器、２４は返油バイパス回路、２５は第４の絞り装置、２６はスラッジフィルタで、以上は図１０に示した実施の形態９と同様のものである。２８は油分離器２３と切換弁２の間から分岐し、返油バイパス回路２４のスラッジフィルタ２６の上流部分に合流する液冷媒注入回路、２９は、液冷媒注入回路２８の配管と熱源機側熱交換器３の最も下の部分に流入する空気の一部とが熱交換する液注入回路熱交換器である。
【００８４】
次に、冷媒及び冷凍機油の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れ、及び油分離器２３の動作は実施の形態８と全く同様なので説明を省略し、返油バイパス回路２４及び液冷媒注入回路２８の冷媒及び冷凍機油の流れを説明する。油分離器２３により冷凍機油が分離された高温高圧のガス冷媒の一部は液冷媒注入回路２８へ流入し、液注入回路熱交換器２９で熱源機側熱交換器３の最下部に流入する空気の一部と熱交換して温度が低下して液化し、油分離器２３で分離され返油バイパス回路２４に流入した冷凍機油と合流する。この合流した液冷媒及び冷凍機油はスラッジフィルタ２６を経て、第４の絞り装置２５で低圧まで減圧されて、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流する。
なお、この実施の形態１２でも実施の形態３，５、６及び１０と同様、暖房時において蒸発器となる、液注入回路熱交換器２９が設けられる熱源機側熱交換器３の最下部においては、上部からのドレンの流れで風が通りにくく霜が発生し成長しやすいが、液注入回路熱交換器２９により暖められ、着霜しにくくなる。
【００８５】
また、圧縮機１の摺動部で生成される冷凍機油劣化物は、冷凍機油とともに吐出ガスに混ざって冷媒回路中に吐出され、油分離器２３で冷凍機油とともに分離され返油バイパス回路２４に流入し、液冷媒注入回路２８の液注入回路熱交換器２９から流出する液冷媒と合流することにより、冷凍機油中の冷媒濃度を高くしてスラッジフィルタ２６に流入し捕捉される。これにより、冷凍機油中に溶け込んでいた冷凍機油劣化物は析出するため、スラッジフィルタ２６では固体として存在するスラッジとともに元々冷凍機油に溶け込んでいたものも捕捉することができる。したがって、アキュムレータ４に流入し、圧縮機１に戻る冷凍機油中の冷凍機油劣化物含有率はさらに低下し、油戻し穴５に付着するスラッジの量は低下する。それにより、圧縮機１内部の冷凍機油が枯渇することがなくなり、異常な高圧上昇・低圧低下・それによる吐出ガス温度上昇も回避でき、信頼性が著しく向上する。また、圧縮機１から吐出された冷媒などが返油バイパス回路２４を経て圧縮機１へ戻るサイクルは途中で液側接続冷媒配管９、ガス側接続冷媒配管１０を経由しない。したがって、液側接続冷媒配管９やガス側接続冷媒配管１０の施工時に十分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルが運転中にスラッジフィルタ２６に流入することがなく、流路を閉塞したり、スラッジフィルタを変形・破壊したりする危険性がない。
【００８６】
実施の形態１３．
以下、この発明の実施の形態１３を図１４によって説明する。図１４はこの実施の形態１３にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管、２３は油分離器、２４は返油バイパス回路、２５は第４の絞り装置、２６はスラッジフィルタ、２８は液冷媒注入回路で、以上は図１３に示した実施の形態１２と同様のものである、２９は、液冷媒注入回路２８の配管と切換弁２とアキュムレ−タ４との間の部分とが熱交換する液注入回路熱交換器である。
【００８７】
次に、冷媒及び冷凍機油の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れ、及び油分離器２３の動作は実施の形態８と全く同様なので説明を省略し、返油バイパス回路２４及び液冷媒注入回路２８の冷媒及び冷凍機油の流れを説明する。油分離器２３により冷凍機油が分離された高温高圧のガス冷媒の一部は液冷媒注入回路２８へ流入し、液注入回路熱交換器２９で切換弁２を経て圧縮機１へ戻る低温低圧の冷媒と熱交換して温度が低下して液化し、油分離器２３で分離され返油バイパス回路２４に流入した冷凍機油と合流する。この合流した液冷媒及び冷凍機油はスラッジフィルタ２６を経て、第４の絞り装置２５で低圧まで減圧されて、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流する。
【００８８】
また、圧縮機１の摺動部で生成される冷凍機油劣化物は、冷凍機油とともに吐出ガスに混ざって冷媒回路中に吐出され、油分離器２３で冷凍機油とともに分離され返油バイパス回路２４に流入し、液冷媒注入回路２８の液注入回路熱交換器２９から流出する液冷媒と合流することにより、冷凍機油中の冷媒濃度を高くしてスラッジフィルタ２６に流入し捕捉される。これにより、冷凍機油中に溶け込んでいた冷凍機油劣化物が析出するため、スラッジフィルタ２６では固体として存在するスラッジとともに元々冷凍機油に溶け込んでいたものも捕捉することができる。したがって、アキュムレータ４に流入し、圧縮機１に戻る冷凍機油中の冷凍機油劣化物含有率はさらに低下し、油戻し穴５に付着するスラッジの量は低下する。それにより、圧縮機１内部の冷凍機油が枯渇することがなくなり、異常な高圧上昇・低圧低下・それによる吐出ガス温度上昇も回避でき、信頼性が著しく向上する。また、圧縮機１から吐出された冷媒などが返油バイパス回路２４を経て圧縮機１へ戻るサイクルは途中で液側接続冷媒配管９、ガス側接続冷媒配管１０を経由しない。したがって、液側接続冷媒配管９やガス側接続冷媒配管１０の施工時に十分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルが運転中にスラッジフィルタ２６に流入することがなく、流路を閉塞したり、スラッジフィルタを変形・破壊したりする危険性がない。
【００８９】
実施の形態１４．
以下、この発明の実施の形態１４を図１５によって説明する。図１５はこの実施の形態１４にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、６は第２の絞り装置、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管で以上は図１に示した実施の形態１と同様のもので、２３は油分離器、２４は返油バイパス回路、２５は第４の絞り装置、２６はスラッジフィルタで、これらは図１３に示した実施の形態１２と同様のものである、２８は第２の絞り装置６と液側接続冷媒配管９との間から分岐し、返油バイパス回路２４のスラッジフィルタ２６の上流部分に合流する液冷媒注入回路である。
【００９０】
次に、冷媒及び冷凍機油の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第２の絞り装置６、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れは実施の形態１と全く同様であり、油分離器２３の動作は実施の形態８と同様なので説明を省略し、返油バイパス回路２４及び液冷媒注入回路２８の冷媒及び冷凍機油の流れを説明する。油分離器２３で分離された冷凍機油は返油バイパス回路２４に流入する。また、冷房時には熱源機側熱交換器３にて空気と熱交換して凝縮・液化し全開状態の第２の絞り装置６を通過した液冷媒が、暖房時には室内機側熱交換器７ｂ、７ｃ、７ｄにて空気と熱交換して凝縮・液化し全開状態の第１の絞り装置８ａ、８ｂ、８ｃ、液側接続冷媒配管９を経た液冷媒が、一部液冷媒注入回路２８に流入し、返油バイパス回路２４に流入した冷凍機油と合流する。この合流した液冷媒及び冷凍機油はスラッジフィルタ２６を経て、第４の絞り装置２５で低圧まで減圧されて、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流する。
【００９１】
また、圧縮機１の摺動部で生成される冷凍機油劣化物は、冷凍機油とともに吐出ガスに混ざって冷媒回路中に吐出され、油分離器２３で冷凍機油とともに分離され返油バイパス回路２４に流入し、液冷媒注入回路２８に流入した液冷媒と合流することにより、冷凍機油中の冷媒濃度を高くしてスラッジフィルタ２６に流入し捕捉される。これにより、冷凍機油中に溶け込んでいた冷凍機油劣化物が析出するため、スラッジフィルタ２６では固体として存在するスラッジとともに元々冷凍機油に溶け込んでいたものも捕捉することができる。したがって、アキュムレータ４に流入し、圧縮機１に戻る冷凍機油中の冷凍機油劣化物含有率はさらに低下し、油戻し穴５に付着するスラッジの量は低下する。それにより、圧縮機１内部の冷凍機油が枯渇することがなくなり、異常な高圧上昇・低圧低下・それによる吐出ガス温度上昇も回避でき、信頼性が著しく向上する。また、圧縮機１から吐出された冷媒などが返油バイパス回路２４を経て圧縮機１へ戻るサイクルは途中で液側接続冷媒配管９、ガス側接続冷媒配管１０を経由しない。したがって、液側接続冷媒配管９やガス側接続冷媒配管１０の施工時に十分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルが運転中にスラッジフィルタ２６に流入することがなく、流路を閉塞したり、スラッジフィルタを変形・破壊したりする危険性がない。
【００９２】
実施の形態１５．
以下、この発明の実施の形態１５を図１６によって説明する。図１５はこの実施の形態１５にかかる空気調和装置の冷媒回路図である。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５はアキュムレ−タ４の油戻し穴、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管、２３は油分離器、２４は返油バイパス回路、２５は第４の絞り装置、２６はスラッジフィルタで、以上は図１３に示した実施の形態１２と同様のものである。２８は油分離器２３と切換弁２の間から分岐し、他端が切換弁２と圧縮機１との間の冷媒配管に接続する液冷媒注入回路、３０は液冷媒注入回路２８途中にある第５の絞り装置、２９は、液冷媒注入回路２８の第５の絞り装置３０の上流部と下流部との間で熱交換する液注入回路熱交換器である。また、返油バイパス回路２４のスラッジフィルタ２６の上流部分と、液冷媒注入回路２８の第５の絞り装置３０の上流部分とは配管で接続されている。
【００９３】
次に、冷媒及び冷凍機油の流れを図によって説明する。圧縮機１、切換弁２、熱源機側熱交換器３、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れ、及び油分離器２３の動作は実施の形態８と全く同様なので説明を省略し、返油バイパス回路２４及び液冷媒注入回路２８の冷媒及び冷凍機油の流れを説明する。油分離器２３により冷凍機油が分離された高温高圧のガス冷媒の一部は液冷媒注入回路２８へ流入し、液注入回路熱交換器２９で液冷媒注入回路２８低圧側の冷媒と熱交換して温度が低下して液化し、その一部が第５の絞り装置３０へ流入して低圧まで減圧され、液注入回路熱交換器２９で高圧側の冷媒により加熱されガス化して、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流する。また、液注入回路熱交換器２９高圧側で液化した冷媒の残部は、油分離器２３で分離され返油バイパス回路２４に流入した冷凍機油と合流する。この合流した液冷媒及び冷凍機油はスラッジフィルタ２６を経て、第４の絞り装置２５で低圧まで減圧されて、切換弁２とアキュムレータ４との間で切換弁２を経た主冷媒回路の冷媒と合流する。
【００９４】
また、圧縮機１の摺動部で生成される冷凍機油劣化物は、冷凍機油とともに吐出ガスに混ざって冷媒回路中に吐出され、油分離器２３で冷凍機油とともに分離され返油バイパス回路２４に流入し、液冷媒注入回路２８の液注入回路熱交換器２９の高圧側から流出する一部の液冷媒と合流することにより、冷凍機油中の冷媒濃度を高くしてスラッジフィルタ２６に流入し捕捉される。これにより、冷凍機油中に溶け込んでいた冷凍機油劣化物が析出するため、スラッジフィルタ２６では固体として存在するスラッジとともに元々冷凍機油に溶け込んでいたものも捕捉することができる。したがって、アキュムレータ４に流入し、圧縮機１に戻る冷凍機油中の冷凍機油劣化物含有率はさらに低下し、油戻し穴５に付着するスラッジの量は低下する。それにより、圧縮機１内部の冷凍機油が枯渇することがなくなり、異常な高圧上昇・低圧低下・それによる吐出ガス温度上昇も回避でき、信頼性が著しく向上する。また、圧縮機１から吐出された冷媒などが返油バイパス回路２４を経て圧縮機１へ戻るサイクルは途中で液側接続冷媒配管９、ガス側接続冷媒配管１０を経由しない。したがって、液側接続冷媒配管９やガス側接続冷媒配管１０の施工時に十分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルが運転中にスラッジフィルタ２６に流入することがなく、流路を閉塞したり、スラッジフィルタを変形・破壊したりする危険性がない。
【００９５】
実施の形態１６．
図１７は実施の形態１〜６において使用されるドライヤ１６の一実施の形態１６を示す縦断面図で、同図（ａ）は冷媒の流れ方向が左から右になるよう、同図（ｂ）は冷媒の流れ方向が下から上にになるよう、同図（ｃ）は冷媒の流れ方向が上から下にになるようドライヤを配設した場合をそれぞれ示している。図において、５０は円筒状の容器、５１は容器５０の一端に設けられた流入配管、５２は容器５０の他端に設けられた流出配管、５３は合成ゼオライトを主成分とし、活性アルミナなどを配合し、接着剤などのバインダで固めたドライヤコア、５４は冷凍機油である。
【００９６】
流入配管５１から流入した冷媒はドライヤコア５３によって冷媒中に含まれている水分が吸収されるが、冷媒の流路としては非常に細かなドライヤコアの目を通るため、それよりも大きいものはここで捕捉される。また、ドライヤによっては、ドライヤコア５３の上流側又は下流側にフィルタを備えた構成のものがあるが、そのフィルタ部でも異物は捕捉される。したがって、実施の形態９〜１５におけるスラッジフィルタ２６としてこの構成のドライヤを用いることができる。このようにスラッジフィルタ２６としてドライヤを使用することで、返油バイパス回路２４を流れる冷凍機油より直接水分を吸収することができ、スラッジフィルタ機能と水分捕捉機能をも合わせ持つことができる。これにより、冷凍機油の加水分解を抑制しつつ、冷凍機油中の冷凍機油劣化物含有率も低減でき、結果として主冷媒回路中の含有水分量も冷凍機油劣化物含有率も低減し、第１の絞り装置８ｂ、８ｃ、８ｄ、油戻し穴５等に付着するスラッジの量は低下する。
【００９７】
また、実施の形態１〜６においてドライヤ１６として、実施の形態９〜１５においてスラッジフィルタ２６として、図１７に示す構成のものを使用する場合、同図（ａ）や（ｂ）のように設置すると、過渡状態においてドライヤ容器５０内に液冷媒又は冷凍機油が充分たまらないと、容器５０からは液冷媒又は冷凍機油が流出することができない。これに対し、同図（ｃ）に示すように冷媒の流れ方向が上から下にになるよう配設されると、容器５０に流入した液冷媒又は冷凍機油は速やかに流出するため、すばやく安定した運転になることができ、また、冷凍機油が圧縮機より枯渇することがない。
【００９７】
実施の形態１７．
図１８は以上の各実施の形態において使用される実施の形態１７にかかるアキュムレータ４の一例を示す縦断面図で、図において、６０はアキュムレ−タ容器、６１は容器６０の底より容器内の上部まで挿入された流入配管、６２は容器６０の底より容器内の上部まで挿入され、その下部に冷凍機油を戻すための油戻し穴５を備えた流出配管、６３は容器６０内の下部に溜まっている液冷媒と冷凍機油との混合液、６４は容器６０内部の下部空間と流出配管６２の上部管端部とを接続する返油配管、６５は返油配管６４の、容器６０内部の下部空間側の一端に設けられたオリフィスである。
【００９８】
次に、アキュムレ−タ４の返油動作について説明する。アキュムレ−タ内の混合液６３の液面と流出配管６２の管端部との高さの差をｈ、流出配管内部の冷媒の流速をｕ、流出配管より流出する冷媒の密度をρｇ、混合液６３の密度をρ_lとすると、オリフィス６５の入口圧力から出口圧力を引いた、オリフィス６５の前後に発生する差圧ΔＰは
ΔＰ＝ｋ₁・ρ_g・ｕ₂／２−ｋ₂・ρ_l・ｈ
で表わされる（ここにｋ₁、ｋ₂は正の定数）。ただし、返油配管６４は充分太くなされているので、ここでの圧力損失は無視される。ΔＰが正であれば返油可能、負であらば返油不能であることを意味する。また、ΔＰが正で大きい程返油流量は多くなる。
【００９９】
この式から明らかなように、冷媒流速ｕが大きいと右辺第２項に比して第１項が大きく、たとえ液面が低くても返油可能である。一方、冷媒流速ｕが小さいと多少液面が高くても第２項の負量が大きく、混合液が流出配管６４に流出する流量は少ない。冷媒流量が多い場合には圧縮機から吐出される冷凍機油の比率が大きいが、冷媒流量が少ない場合には圧縮機から吐出される冷凍機油の比率は小さい。したがって、冷凍機油劣化成分が油戻し穴５に付着した場合に返油不足となるのは、冷媒流量が多い場合である。油戻し穴５を大きくすると、冷媒流量が多い場合には充分に油が戻るが、冷媒流量が少なくかつアキュムレ−タ４の液面が高い場合には液バックが多くなり圧縮機の潤滑性が低下する。
【０１００】
ところが、図１８に示すように、油戻し穴５とともに返油配管６４を設けると、スラッジの付着により返油流量が問題となる、冷媒流量の多い場合には返油配管６４より返油可能で、スラッジ付着による返油不足分を補うことができる。また、冷媒流量が少なくかつアキュムレ−タ４の液面が高い場合にも返油配管６４よりの液バックは小さいため、液バック過多による圧縮機の潤滑性低下にはつながらない。このように、アキュムレ−タ４内に返油配管６４を設けることにより、スラッジが油戻し穴５に付着しても返油不足に陥ることもなく、液バック過多になることもない信頼性の高い空気調和装置を得ることができる。
【０１０１】
なお、図１９に示すように返油配管６４のオリフィス６５を返油配管６４の流出配管６２側の一端に設けた場合、図２０のように返油配管６４を毛細管６６で構成し、返油配管６４の機能とオリフィス６５の機能を併せ持たせた場合、図２１に示すように、流出配管６２を容器６０の上方から挿入し、返油配管６４を容器６０の外側に設け、油戻し穴５の代わりに油戻し配管及びオリフィス６７を設けた場合、図２２に示すように流出配管６２がＵ字形状となっている場合にも、実施の形態１７と同様の効果を有するものである。
【０１０２】
実施の形態１８．
以下、この発明の実施の形態１８を図２３、図２４及び図２５によって説明する。図２３はこの実施の形態１８にかかる空気調和装置の冷媒回路及び制御回路を示す構成図、図２４はこの実施の形態２２にかかる絞り装置制御装置を示すブロック線図、図２５はこれの絞り装置制御動作を説明するフローチャートである。図において、Ａは熱源機、Ｂ、Ｃ、Ｄは室内機、１は圧縮機、２は切換弁、３は熱源機側熱交換器、４はアキュムレ−タ、５は油戻し穴、７ｂ、７ｃ、７ｄは室内機側熱交換器、８ｂ、８ｃ、８ｄは第１の絞り装置、９は液側接続冷媒配管、１０はガス側接続冷媒配管で、以上は図２８に示す従来例と同様のものである。
【０１０３】
３１は圧縮機１の吐出部と切換弁２との間に設けられた吐出圧力検出手段、３２は熱源機側熱交換器３と液側接続冷媒配管９との間に設けられた第３の温度検出手段、３３ｂ、３３ｃ、３３ｄは室内機Ｂ、Ｃ、Ｄ内の第１の絞り装置８ｂ、８ｃ、８ｄと室内側熱交換器７ｂ、７ｃ、７ｄとの間に設けられた第４の温度検出手段、３４ｂ、３４ｃ、３４ｄは室内機Ｂ、Ｃ、Ｄ内の室内側熱交換器７ｂ、７ｃ、７ｄのガス側接続冷媒配管１０側一端に設けられた第５の温度検出手段、３５は絞り装置制御装置、３６は第３の温度検出手段３２の検出値、第１の圧力検出手段３１の検出値、そして混合冷媒の組成演算手段２２の演算結果から第３の温度検出手段３２の設置部分の過冷却度を演算するＳＣ演算手段、３７は第４の温度検出手段３３ｂ、３３ｃ、３３ｄの検出値、第５の温度検出手段３４ｂ、３４ｃ、３４ｄの検出値から室内側熱交換器出口部の過熱度を演算するＳＨ演算手段、３８はＳＣ演算手段３６、ＳＨ演算手段３７の演算結果から第１の絞り装置８ｂ、８ｃ、８ｄの開度を制御する第１の絞り装置制御手段、３９ｂ、３９ｃ、３９ｄは各室内機Ｂ、Ｃ、Ｄに設けられた送風機、４０ｂ、４０ｃ、４０ｄは各室内機Ｂ、Ｃ、Ｄに設けられたドレンポンプ、４１ｂ、４１ｃ、４１ｄは除霜制御装置である。
【０１０４】
圧縮機１、切換弁２、熱源機側熱交換器３、第１の絞り装置８ｂ、８ｃ、８ｄ、及び室内機側熱交換器７ｂ、７ｃ、７ｄからなる主冷媒回路の冷房時、暖房時の冷媒の流れは従来例と全く同様なので説明を省略し、絞り装置制御装置による第１の絞り装置８ｂ、８ｃ、８ｄの制御動作を図２５のフロ−チャ−トによって説明する。ステップ１０５で、第４の温度検出手段３３ｂ、３３ｃ、３３ｄの検出値及び第５の温度検出手段３４ｂ、３４ｃ、３４ｄの検出値からＳＨ演算手段３７によって演算された演算結果ＳＨと、予め設定されたＳＨの上限値ＳＨＨとが比較され、ＳＨ≦ＳＨＨであればステップ１０６に進み、ＳＨ＞ＳＨＨであればステップ１０８に進む。ステップ１０６では、ＳＨ演算手段３６の演算結果ＳＨと、予め設定されたＳＨの下限値ＳＨＬとが比較され、ＳＨ≧ＳＨＬであればステップ１０７に進んで第１の絞り装置８ｂ、８ｃ、８ｄの開度が減少され、ＳＨ＜ＳＨＬであればそのまま何もしない。ステップ１０８では第１の絞り装置８ｂ、ｃ、ｄの開度Ｓｊと、予め設定された上限開度ＭＡＸとが比較され、
Ｓｊ≦ＭＡＸであればステップ１０９へ進んで第１の絞り装置８ｂ、８ｃ、８ｄの開度が増加され、Ｓｊ＞ＭＡＸであればステップ１１０へ進む。
【０１０５】
ステップ１１０で、第３の温度検出手段３２の検出値、第１の圧力検出手段３１の検出値、及び混合冷媒の組成演算手段２２の演算結果からＳＣ演算手段３６によって演算された演算結果と、予め設定されたＳＣの下限値ＳＣＬとが比較され、ＳＣ＞ＳＣＬであればステップ１１１に進んで上限開度ＭＡＸが大きく設定し直され、ＳＣ≦ＳＣＬであれば何もしない。このように、第１の絞り装置８ｂ、８ｃ、８ｄが、スラッジ付着により流量不足に陥った場合において、第３の温度検出手段３２のある部分で十分に過冷却が確保されていて制御が発散しない場合には、最大開度を大きく設定するため、流量不足は解消される。
【０１０６】
実施の形態１９．
以下、この発明の実施の形態１９を図２３、図２６及び図２７によって説明する。図２６はこの実施の形態１９にかかる除霜制御装置を示すブロック線図、図２７はこれの除霜制御動作を説明するフローチャートである。図２６において、３４ｂ、３４ｃ、３４ｄは室内機Ｂ、Ｃ、Ｄ内の室内側熱交換器７ｂ、７ｃ、７ｄのガス側接続冷媒配管１０側一端に設けられた第５の温度検出手段、３９ｂ、３９ｃ、３９ｄは各室内機Ｂ、Ｃ、Ｄに設けられた送風機、４０ｂ、４０ｃ、４０ｄは各室内機Ｂ、Ｃ、Ｄに設けられたドレンポンプ、４１ｂ、４１ｃ、４１ｄは除霜制御装置、４２はシステムモ−ドが冷房か否かを判定するシステムモ−ド判定手段、４３ｂ、４３ｃ、４３ｄは各室内機Ｂ、Ｃ、Ｄのモ−ドが冷房か否かを判定する室内機モ−ド判定手段、４４ｂ、４４ｃ、４４ｄは各室内機Ｂ、Ｃ、Ｄの計時手段、４５は冷房していない室内機の熱交換器の霜を解かすための運転を制御する室内機除霜運転制御手段である。
【０１０７】
一部の室内機例えばＢが冷房運転しかつ室温及び外気温度も低く、残りの室内機Ｃ、Ｄが停止している場合に、停止中の室内機Ｃ、Ｄの第１の絞り装置８ｄが付着したスラッジによって完全な閉止状態とならずに、微小流量の冷媒が流れる場合がある。この場合、この微小流量の冷媒をガス化する熱がなくかつ室温・外気温度が低いため、停止中の室内機Ｃ、Ｄの室内側熱交換器７ｄは着霜する。このような状態に陥ると、室内機Ｃ、Ｄの第５の温度検出手段３４ｃ、３４ｄの温度は低温となる。このような室内機Ｃ、Ｄの第５の温度検出手段３４ｃ、３４ｄの検出値Ｔ₅が予め設定された第１の所定温度Ｔ_Lより低い状態が第１の所定時間τ_1B続くと、これが第５の温度検出手段３４ｃ、３４ｄ、システムモ−ド判定手段４２、室内機モ−ド判定手段４３ｃ、４３ｄ及び計時手段４４ｃ、４４ｄによって検出され、室内機除霜運転制御手段４５によって、送風機３９ｃ、３９ｄが運転され室内側熱交換器Ｃ、Ｄの霜を解かし、同時にドレンポンプ４０ｃ、４０ｄも運転されこの時生ずるドレン水を排水するよう制御される。
【０１０８】
また、送風機３９ｃ、３９ｄの運転開始後第２の所定時間τ_2B経過後に、室内機Ｃ、Ｄの第５の温度検出手段３４ｃ、３４ｄの検出値Ｔ₅がＴ_Lより高めに予め設定された第２の所定温度Ｔ_Hより高くなっていると送風機３９ｃ、３９ｄを停止させ、送風機３９ｃ、３９ｄ停止後もしばらくの間はドレン水発生が続くため、送風機３９ｃ、３９ｄ停止後第３の所定時間τ_3B経過後にドレンポンプ４０ｃ、４０ｄを停止させるよう制御される。以上により、停止中の室内機の第１の絞り装置が付着したスラッジによって完全な閉止状態とすることができない場合にも停止中の室内機の室内側熱交換器の霜が成長し続けることはなく、不具合は発生しない。
【０１０９】
次に、室内機除霜運転制御手段４５の制御動作を図２７のフロ−チャ−トによって説明する。システムモ−ド判定手段４２の判定の結果、システムモ−ドが冷房で、室内機モ−ド判定手段４３ｂ、４３ｃ、４３ｄの判定の結果、室内機モ−ドが冷房でなく、計時手段４４ｂ、４４ｃ、４４ｄによる第１の計時τ₁が第１の所定時間τ_1B経過し、かつ、第５の温度検出手段３４ｂ、３４ｃ、３４ｄの検出値Ｔ₅が第１の所定温度Ｔ_L以下であると、ステップ１１２からステップ１１３、１１４、１１５を経てステップ１１６に進み、計時手段４４ｂ、４４ｃ、４４ｄによる第２の計時τ₂が０にクリアされステップ１１７に進み、送風機３９ｂ、３９ｃ、３９ｄ及びドレンポンプ４０ｂ、４０ｃ、４０ｄの運転が開始される。
【０１１０】
その後ステップ１１８に進み第２の計時τ₂が第２の所定時間τ_2B経過したかが、ステップ１１９に進み第５の温度検出手段３４ｂ、３４ｃ、３４ｄの検出値Ｔ₅が第２の所定温度Ｔ_Hより高くなったかが判定され、これら条件が満足される迄この判定が続けられ、満足された時点でステップ１２０に進み、送風機３９ｂ、３９ｃ、３９ｄの運転が停止され、ステップ１２１で計時手段４４ｂ、４４ｃ、４４ｄによる第３の計時τ₃が０にクリアされステップ１２２に進み、第３の計時τ₃が第３の所定時間τ_3B経過した後ステップ１２３に進み、ドレンポンプ４０ｂ、４０ｃ、４０ｄの運転が停止される。
【０１１１】
【発明の効果】
【０１１７】
本願の発明によれば、圧縮機吐出部に油分離器を設け、分離した冷凍機油を圧縮機吸入部に戻す返油バイパス回路を設けたので、主冷媒回路の絞り装置を流れる冷凍機油の流量は著しく低下し、冷凍機油と共に循環する冷凍機油劣化物の積算流量も低下する。これにより、冷凍機油劣化物がスラッジとなって主冷媒回路の絞り装置に付着する量も減少する。以上により、主冷媒回路の絞り装置の流量不足が回避でき、空調能力の不足はなくなる。また、異常な高圧上昇・低圧低下・それによる吐出ガス温度上昇を回避でき、信頼性が著しく向上するという効果がある。
【０１１８】
本願の発明によれば、前記の発明において、返油バイパス回路途中にスラッジフィルタを設けたので、前記の発明の効果の外に、さらに、圧縮機内部で生成された冷凍機油劣化物は返油バイパスにおいてスラッジフィルタで捕捉され、冷凍機油中の冷凍機油劣化物含有率は低下し、主冷媒回路の絞り装置、油戻し穴に付着するスラッジの量は低下し、また、圧縮機から吐出された冷媒などが返油バイパスを経て圧縮機へ戻るサイクルは途中で液側接続冷媒配管、ガス側接続冷媒配管を経由しないので、液側接続冷媒配管やガス側接続冷媒配管の施工時に充分な無酸化ロウ付けを実施しないような場合などに発生する酸化スケ−ルが運転中にスラッジフィルタに流入することがなく、流路を閉塞したり、スラッジフィルタを変形・破壊したりする危険性がない等の効果がある。
【０１１９】
本願の他の発明によれば、前記の発明において、返油バイパス回路途中のスラッジフィルタ上流に冷凍機油を冷却するバイパス熱交換器を設けたので、前記の発明の効果の外に、スラッジフィルタに流入する冷凍機油の温度が低下して冷凍機油中の冷媒の濃度が高まることにより、冷凍機油中に溶け込んでいた冷凍機油劣化物が析出されて元々冷凍機油に溶け込んでいたものもスラッジフィルタにより捕捉され、主冷媒回路の冷凍機油中の冷凍機油劣化物含有率はさらに低下するという効果がある。
【０１２０】
本願の他の発明によれば、前記の発明において、返油バイパス回路途中のスラッジフィルタ上流に液冷媒を注入する液冷媒注入回路を設けたので、前記の発明の効果の外に、返油バイパス回路中の冷凍機油が液注入回路から流出する液冷媒と合流することにより、スラッジフィルタに流入する冷凍機油中の冷媒濃度が高まり、冷凍機油中に溶け込んでいた冷凍機油劣化物が析出されて元々冷凍機油に溶け込んでいたものもスラッジフィルタにより捕捉され、主冷媒回路の冷凍機油中の冷凍機油劣化物含有率はさらに低下するという効果がある。
【０１２１】
本願の他の発明によれば、前記の発明において、返油バイパス途中のスラッジフィルタを、水分を吸収しかつスラッジフィルタ機能を有するドライヤとしたので、前記の発明の効果の外に、返油バイパスを流れる冷凍機油より直接水分を吸収することにより、冷凍機油の加水分解が抑制され、主冷媒回路の冷凍機油中の冷凍機油劣化物含有率はさらに低下するという効果がある。
【０１２３】
本願の他の発明によれば、前記の発明において、バイパス熱交換器の全部または一部として熱源機側熱交換器の最下部を通す構成としたので、前記の発明の効果の外に、上部でのドレンの流れで風が通りにくく、着霜しやすい熱交換器の最も下の部分が暖められ着霜しにくくなるという効果がある。
【図面の簡単な説明】
【図１】 この発明の実施の形態１にかかる空気調和装置の冷媒回路図。
【図２】 実施の形態２にかかる空気調和装置の冷媒回路図。
【図３】 実施の形態３にかかる空気調和装置の冷媒回路図。
【図４】 実施の形態４にかかる空気調和装置の冷媒回路図。
【図５】 実施の形態５にかかる空気調和装置の冷媒回路図。
【図６】 実施の形態６にかかる空気調和装置の冷媒回路図。
【図７】 実施の形態７にかかる空気調和装置の組成演算に関するブロック線図。
【図８】 実施の形態７にかかる空気調和装置の組成演算手段の動作を示すフロ−チャ−ト。
【図９】 実施の形態８にかかる空気調和装置の冷媒回路図。
【図１０】 実施の形態９にかかる空気調和装置の冷媒回路図。
【図１１】 実施の形態１０にかかる空気調和装置の冷媒回路図。
【図１２】 実施の形態１１にかかる空気調和装置の冷媒回路図。
【図１３】 実施の形態１２にかかる空気調和装置の冷媒回路図。
【図１４】 実施の形態１３にかかる空気調和装置の冷媒回路図。
【図１５】 実施の形態１４にかかる空気調和装置の冷媒回路図。
【図１６】 実施の形態１５にかかる空気調和装置の冷媒回路図。
【図１７】 実施の形態１〜６において使用されるドライヤの一実施の形態１６を示す縦断面図。
【図１８】 各実施の形態において使用される実施の形態１７にかかるアキ態１７を示す縦断面図。
【図１９】 アキュムレータの一実施の形態１８を示す縦断面図。
【図２０】 アキュムレータの一実施の形態１９を示す縦断面図。
【図２１】 アキュムレータの一実施の形態２０を示す縦断面図。
【図２２】 アキュムレータの一実施の形態２１を示す縦断面図。
【図２３】 実施の形態２２及び２３にかかる空気調和装置の冷媒回路及び制御回路を示す構成図。
【図２４】 実施の形態２２にかかる絞り装置制御装置を示すブロック線図。
【図２５】 実施の形態２２にかかる絞り装置制御動作を説明するフローチャート。
【図２６】 実施の形態２３にかかる除霜制御装置を示すブロック線図。
【図２７】 実施の形態２３にかかる除霜制御動作を説明するフローチャート。
【図２８】 従来の空気調和装置の冷媒回路図。
【符号の説明】
Ａ 熱源機、Ｂ、Ｃ、Ｄ 室内機、１ 圧縮機、２ 切換弁、３ 熱源機側熱交換器、４ アキュムレ−タ、５ アキュムレ−タ４の油戻し穴、６ 第２の絞り装置（暖房時絞り装置）、７ｂ、７ｃ、７ｄ 室内機側熱交換器、８ｂ、８ｃ、８ｄ 第１の絞り装置（冷房時絞り装置）、９ 液側接続冷媒配管、１０ ガス側接続冷媒配管、１５ バイパス回路、１６ ドライヤ、１７ 第３の絞り装置（バイパス絞り装置）、１８、２７ バイパス熱交換器、１８ａ 第１のバイパス熱交換器、１８ｂ 第２のバイパス熱交換器、１９ 第１の温度検出手段、２０ 第２の温度検出手段、２１ 吸入圧力検出手段、２２ 組成演算手段、２３ 油分離器、２４ 返油バイパス回路、２５ 第４の絞り装置、２６ スラッジフィルタ、２８ 液冷媒注入回路、２９ 液注入回路熱交換器、３０ 第５の絞り装置、３１ 吐出圧力検出手段、３２ 第３の温度検出手段、３３ｂ、３３ｃ、３３ｄ 第４の温度検出手段、３４ｂ、３４ｃ、３４ｄ 第５の温度検出手段、３５ 絞り装置制御装置、３６ ＳＣ演算手段、３７ ＳＨ演算手段、３８絞り装置制御手段、３９ｂ、３９ｃ、３９ｄ 除霜用送風機、４０ｂ、４０ｃ、４０ｄ ドレンポンプ、４１ｂ、４１ｃ、４１ｄ 除霜制御装置、６２ アキュムレ−タ流出配管、６４ 返油配管。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner that uses a hydrofluorocarbon refrigerant as a working medium and oil that is compatible with the refrigerant as refrigeration oil.
[0002]
[Prior art]
FIG. 28 is a refrigerant circuit diagram of a conventional air conditioner, in which A is a heat source unit, B, C, and D are indoor units, 1 is a compressor, 2 is a switching valve, and 3 is a heat source unit side heat exchanger. 4 is an accumulator, 5 is an oil return hole of the accumulator 4, 6 is a heating expansion device (hereinafter referred to as a second expansion device), 7b, 7c and 7d are indoor unit side heat exchangers, 8b and 8c. 8d is a cooling-time expansion device (hereinafter referred to as a first expansion device), 9 is one end of the heat source unit A on the heat source unit side heat exchanger 3 side, and the first expansion unit 8b of the indoor units B, C, and D, The liquid side connection refrigerant pipes 10 for connecting one end on the 8c, 8d side are one end on the switching valve 2 side of the heat source unit A and the indoor unit side heat exchangers 7b, 7c, 7d of the indoor units B, C, D. Gas-side connecting refrigerant pipes that connect one end of the side, 11 and 12 are used to store a desiccant mainly composed of synthetic zeolite in a cylindrical container or pipe. Was, dryer to moisture absorption of moisture mixed in the refrigerant circuit, 13,14b, 14c, 14d is a sludge filter to trap sludge built fine mesh filter cylindrical container and the pipe.
[0003]
Next, the flow of the refrigerant will be described with reference to the drawings. In the figure, solid arrows indicate the flow during cooling, and broken arrows indicate the flow during heating. First, at the time of cooling, the gas refrigerant compressed to high temperature and high pressure by the compressor 1 flows into the heat source machine side heat exchanger 3 through the switching valve 2, and is condensed by exchanging heat with air and the like. Becomes a refrigerant. Furthermore, the second expansion device 6 that is fully open during cooling and the liquid side connection refrigerant pipe 9 are passed through to reach the indoor units B, C, and D, and the degree of superheat at the outlets of the indoor unit side heat exchangers 7b, 7c, and 7d is increased. The first throttling devices 8b, 8c, and 8d controlled so as to be within a certain range are throttling to a low-pressure gas-liquid two-phase state. The low-pressure gas-liquid two-phase refrigerant flows into the indoor unit side heat exchangers 7b, 7c, and 7d, exchanges heat with indoor air and gasifies, and forms the gas side connection refrigerant pipe 10, the switching valve 2, and the accumulator 4. It returns to the compressor 1 through this. The refrigerating machine oil inside the accumulator 4 returns to the compressor 1 through the oil return hole 5 together with the liquid refrigerant.
[0004]
At the time of heating, the gas refrigerant compressed to high temperature and high pressure by the compressor 1 reaches the indoor units B, C, D through the switching valve 2 and the gas side connection refrigerant pipe 10, and the indoor unit side heat exchangers 7b, 7c. , 7d, and heat exchange with indoor air to condense and become a high-temperature and high-pressure liquid refrigerant. The liquid refrigerant that has exited the indoor heat exchangers 7b, 7c, and 7d is slightly decompressed by the first expansion devices 7b, 7c, and 7d that are almost fully open, and passes through the liquid-side connection refrigerant pipe 9 to form the second expansion device 6. Where the pressure is reduced to a low-pressure gas-liquid two-phase state. The low-pressure gas-liquid two-phase refrigerant flows into the heat source machine side heat exchanger 3, exchanges heat with air and the like, and gasifies, and returns to the compressor 1 through the switching valve 2 and the accumulator 4. The refrigerating machine oil inside the accumulator 4 returns to the compressor 1 through the oil return hole 5 together with the liquid refrigerant.
[0005]
In the refrigerant circuit as described above, a hydrofluorocarbon refrigerant has recently been used as a working medium instead of a hydrochlorofluorocarbon refrigerant. However, since the hydrofluorocarbon refrigerant does not have a chlorine component, it is not compatible with conventional mineral oil used as refrigerating machine oil, and is separated from the liquid refrigerant inside the accumulator 4 and floats on the top. The refrigeration oil does not return to the compressor 1 from the oil return hole 5. Therefore, in an air conditioner in which a large amount of liquid refrigerant is stored in an accumulator and the compressor 1 is driven by a motor, the polyester is compatible with a hydrofluorocarbon refrigerant and has excellent insulating properties. Oils or polyether oils are generally used.
[0006]
However, these polyester oils and polyether oils absorb moisture and are hydrolyzed when subjected to high temperature conditions such as the sliding portion of the compressor 1 or when processing oxygen or refrigerant circuit components. There is a risk of deterioration due to the remaining components of the processing oil and cleaning agent mixed in. In particular, among the additives used in polyether oil, antiwear agents are generally highly active ester type, and even if the polyether oil does not hydrolyze, the additive is hydrolyzed and compressed in a high temperature state. Thermal degradation occurs at the sliding portion of the machine 1.
[0007]
These deteriorated products generated at that time are either present as solids in the refrigerating machine oil or dissolved and present. When both the solid component and the dissolved component are discharged from the compressor 1, the high-temperature and high-pressure gas refrigerant is mixed into the discharge gas together with the refrigerating machine oil and discharged into the refrigerant circuit. The deterioration product of the refrigeration oil flows into the condenser (the heat source side heat exchanger 3 during cooling and the indoor unit side heat exchangers 7b, 7c and 7d during heating) together with the refrigerant, and the refrigerant is liquefied here. When the refrigerant is liquefied and the refrigerant concentration is increased, the deterioration product of the refrigerating machine oil that has been dissolved in the refrigerating machine oil that has flown with the refrigerant cannot be dissolved, and is deposited as a solid and directly on the pipe wall of the pipe. Things appear.
[0008]
These newly deposited deterioration products flow into the first expansion devices 8b, 8c and 8d and the second expansion device 6 together with the deterioration products originally present as solids. Among the remaining components of processing oil and cleaning agent that are mixed when processing refrigerant circuit components, those that are not compatible with the hydrofluorocarbon refrigerant form a film on the pipe wall, and this non-phase The dissolved component becomes a binder, and the deterioration product of the refrigerating machine oil adheres to the pipe wall of the pipe. In particular, in a throttling device such as a capillary tube in which the flow path cross-sectional area suddenly changes, the flow can stagnate, and the deterioration product of the refrigerating machine oil is markedly attached. In this way, the refrigeration oil deterioration product existing as a solid in the refrigeration oil adheres to the first expansion devices 8b, 8c, 8d and the second expansion device 6 as sludge. Further, when liquid refrigerant is accumulated in the accumulator 4, the degradation product that is a solid or dissolved component of the refrigerating machine oil deposits and adheres to the oil return hole 5 similarly to the expansion device.
[0009]
As measures against sludge adhesion as described above, the dryers 11 and 12 in which a desiccant mainly composed of synthetic zeolite or the like is incorporated in a cylindrical container or pipe are connected to a refrigerant pipe between the switching valve 2 and the accumulator 4; And a sludge filter provided in a liquid-side connection refrigerant pipe 9 between the first throttling devices 8b, 8c, 8d and the second throttling device 6, and having a fine mesh-like filter built in a cylindrical container or pipe Is a refrigerant pipe between the heat source device side heat exchanger 3 and the second expansion device 6, and a refrigerant between the indoor side heat exchangers 7b, 7c, 7d and the first expansion devices 8b, 8c, 8d. Provided in the piping.
[0010]
A dryer 11 provided between the switching valve 2 and the accumulator 4 is connected to the switching valve 2 from the indoor unit side heat exchangers 7b, 7c and 7d during cooling and from the heat source unit side heat exchanger 3 during heating. The gas refrigerant flows in through and the moisture contained in the gas refrigerant is absorbed. The dryer 12 provided in the liquid side connection refrigerant pipe 9 between the first expansion devices 8b, 8c, 8d and the second expansion device 6 is almost fully opened from the heat source unit side heat exchanger 3 during cooling. The second expansion device 6 is heated, and during heating, the indoor unit side heat exchangers 7b, 7c, and 7d are almost fully opened through the first expansion devices 8b, 8c, and 8d, and the liquid is slightly depressurized. A single-phase refrigerant flows in. Accordingly, the pressure loss in the dryer 12 is small, the flow is quiet, and moisture is sufficiently absorbed.
[0011]
In the sludge filter 13 provided in the refrigerant pipe between the heat source machine side heat exchanger 3 and the second expansion device 6, the deterioration product of the refrigeration oil that flows into the heat source machine side heat exchanger 3 together with the refrigerant during cooling The deterioration product dissolved in the refrigerating machine oil deposited and adhered by the liquefaction of the refrigerant in the heat source apparatus side heat exchanger 3 and the decrease in the flow velocity is captured as sludge. Further, in the sludge filters 14b, 14c, 14d provided in the refrigerant pipe between the indoor side heat exchangers 7b, 7c, 7d and the first expansion devices 8b, 8c, 8d, the indoor side heat exchanger 7b during heating is used. , 7c, 7d and the deterioration product of the refrigerating machine oil that flowed together with the refrigerant, and dissolved in the refrigerating machine oil deposited and adhered due to the liquefaction of the refrigerant in the indoor heat exchangers 7b, 7c, 7d and the decrease in the flow velocity. Deteriorated products are trapped as sludge.
[0012]
[Problems to be solved by the invention]
In the conventional air conditioner using the dryer as described above, when the refrigerant gas passes through the dryer 11, a suction pressure loss occurs, the evaporation capability is reduced, and conversely, the reduction of the evaporation capability is to be suppressed. It is necessary to increase the size of the dryer 11. Further, if sufficient non-oxidative brazing is not performed at the time of construction of the refrigerant pipe, an oxidation scale is generated, which flows into the dryers 11 and 12 during operation, and the flow path is blocked or the dryer 11 is crushed. There was a risk of doing. Furthermore, there is a risk that the dryers 11 and 12 may be crushed due to a sudden liquid back generated during a transient operation such as compressor start-up, air conditioning switching, defrost start / end, or a strong flow of refrigerant liquid.
[0013]
Moreover, in the conventional air conditioning apparatus which installed the above sludge filters, between the heat source machine side heat exchanger 3 and the 2nd expansion device 6, and indoor side heat exchangers 7b, 7c, 7d, and 1st There is a problem that it is necessary to install a sludge filter at all positions between the expansion devices 8b, 8c and 8d, and the overall size of the air conditioner increases. In addition, the sludge captured by the sludge filter 13 between the heat source device side heat exchanger 3 and the second expansion device 6 during cooling is separated when the flow is switched to heating, and the heat source device side heat exchanger 3 Then, the oil flows into the accumulator 4 via the switching valve 2 and the oil return hole 5 is closed. Similarly, sludge captured by the sludge filters 14b, 14c, 14d between the indoor heat exchangers 7b, 7c, 7d and the first expansion devices 8b, 8c, 8d during heating is separated when the flow is switched to cooling. Then, the oil flows into the accumulator 4 through the indoor heat exchangers 7b, 7c, 7d and the switching valve 2, and the oil return hole 5 is closed. Furthermore, if sufficient non-oxidative brazing is not performed at the time of construction of the refrigerant pipe, an oxidation scale is generated, which flows into the sludge filters 13, 14b, 14c, and 14d during operation, and the flow path is blocked. There was also a risk of damaging the sludge filter.
[0014]
The present invention has been made to solve the above-described problems. Even if a hydrofluorocarbon refrigerant is used as a working fluid and an oil compatible with the refrigerant is used as a refrigerator oil, the refrigerator oil can be used. It is an object of the present invention to obtain a highly reliable air conditioner that is free from defects due to this, even if a deteriorated product is generated.
[0015]
[Means for Solving the Problems]
[0021]
Claim 1 The air conditioning apparatus according to the present invention includes a main refrigerant circuit composed of a compressor, a condenser, a throttle device, and an evaporator, and uses a hydrofluorocarbon refrigerant as a working medium, and is compatible with the refrigerant. In an air conditioner using a certain amount of oil as refrigerating machine oil, an oil separator is provided at the compressor discharge section, and the return oil bypass circuit for returning the separated refrigerating machine oil to the compressor suction section And a sludge filter for supplementing refrigeration oil deterioration products in the middle of the oil return bypass circuit Is provided.
[0023]
Claim 2 The air conditioner of the present invention according to Claim 1 In the invention described in 1), a bypass heat exchanger for cooling the refrigeration oil is provided upstream of the sludge filter in the middle of the oil return bypass circuit.
[0024]
Claim 3 The air conditioner of the present invention according to Claim 1 In the invention described in 1), a liquid refrigerant injection circuit for injecting liquid refrigerant upstream of the sludge filter in the middle of the oil return bypass circuit is provided.
[0025]
Claim 4 The air conditioner of the present invention according to Claims 1-3 In the invention described in any of the above, the sludge filter in the middle of the oil return bypass is a dryer that absorbs moisture and has a sludge filter function.
[0027]
Claim 5 The air conditioner of the present invention according to Claim 2 In the invention described in (1), the lowermost part of the heat source unit side heat exchanger is passed as all or part of the bypass heat exchanger.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a refrigerant circuit diagram of the air-conditioning apparatus according to the first embodiment. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 The return hole, 6 is the second expansion device, 7b, 7c and 7d are indoor unit side heat exchangers, 8b, 8c and 8d are the first expansion device, 9 is the liquid side connection refrigerant pipe, and 10 is the gas side connection refrigerant. The piping is the same as the conventional example shown in FIG.
[0033]
15 is a bypass circuit that branches from between the second expansion device 6 and the liquid side connection refrigerant pipe 9, and the other end is connected to the refrigerant pipe between the switching valve 2 and the compressor 1, and 16 is a bypass circuit 15. A dryer provided in the middle of the piping, 17 is a bypass throttle device (hereinafter referred to as a third throttle device) provided downstream of the dryer 16 in the middle of the bypass circuit 15, and 18a is a third throttle device 17 of the bypass circuit 15. A first bypass heat exchanger in which heat is exchanged between a portion further downstream and a portion between the second expansion device 6 and the heat source device side heat exchanger 3, and 18 b is a third expansion device 17 of the bypass circuit 15. A second bypass heat exchanger 19 for exchanging heat between the downstream portion and the portion between the second expansion device 6 and the liquid-side connecting refrigerant pipe 9 is provided by the expansion device 17 in the middle of the bypass circuit 15. 1st temperature provided in the upstream part Outlet means 20 is a second temperature detecting means 21 provided downstream of the expansion device 17 in the pipeline of the bypass circuit 15 and upstream of the first and second bypass heat exchangers 18a and 18b. This is suction pressure detection means provided in a portion between the valve 2 and the compressor 1.
[0034]
Next, the flow of the refrigerant will be described with reference to the drawings. First, at the time of cooling, the gas refrigerant compressed to high temperature and high pressure by the compressor 1 flows into the heat source machine side heat exchanger 3 through the switching valve 2, and is condensed by exchanging heat with air and the like. Becomes a refrigerant. Furthermore, the second expansion device 6 that is fully open during cooling and the liquid side connection refrigerant pipe 9 are passed through to reach the indoor units B, C, and D, and the degree of superheat at the outlets of the indoor unit side heat exchangers 7b, 7c, and 7d The first throttling devices 8b, 8c, and 8d controlled so as to be within a certain range are throttling to a low-pressure gas-liquid two-phase state. The low-pressure gas-liquid two-phase refrigerant flows into the indoor unit side heat exchangers 7b, 7c, and 7d, exchanges heat with indoor air and gasifies, and forms the gas side connection refrigerant pipe 10, the switching valve 2, and the accumulator 4. It returns to the compressor 1 through this. The refrigerating machine oil inside the accumulator 4 returns to the compressor 1 through the oil return hole 5 together with the liquid refrigerant.
[0035]
Further, a part of the liquid refrigerant that has passed through the second expansion device 6 in the fully opened state flows into the bypass circuit 15 from the heat source device side heat exchanger 3. In the bypass circuit 15, after passing through the dryer 16, the pressure is reduced to a low pressure by the third expansion device 17 to become a low-temperature low-pressure gas-liquid two-phase refrigerant. This low-temperature and low-pressure gas-liquid two-phase refrigerant is a high-temperature and high-pressure liquid refrigerant that has exited the heat source unit side heat exchanger 3 and a high-temperature and high-pressure refrigerant that has exited the second expansion device 6 in the bypass heat exchangers 18a and 18b. It exchanges heat with the liquid refrigerant, is gasified, and joins the refrigerant that has passed through the indoor units B, C, and D between the switching valve 2 and the compressor 1, and returns to the compressor 1. On the other hand, the liquid refrigerant that has exited the heat source apparatus side heat exchanger 3 is cooled by the first bypass heat exchanger 18a, and the liquid refrigerant that flows into the bypass circuit 15 has a temperature higher than that of the liquid refrigerant that has exited the heat source apparatus side heat exchanger 3. Decreases. The refrigerant further passes through the second expansion device 6 and is cooled by the second bypass heat exchanger 18b, and the liquid refrigerant flowing into the liquid side connection refrigerant pipe 9 is sufficiently subcooled. Therefore, even if the liquid side connection refrigerant pipe 9 is long and the pressure drop of the refrigerant is large while flowing therethrough, the indoor units B, C, and D are installed above the heat source unit A and the liquid side connection refrigerant. Even if the influence of the gravity of the liquid refrigerant in the pipe is great, the refrigerant flowing into the first expansion devices 8a, 8b, 8c can secure a liquid state and can be stably operated.
[0036]
At the time of heating, the gas refrigerant compressed to high temperature and high pressure by the compressor 1 reaches the indoor units B, C, D through the switching valve 2 and the gas side connection refrigerant pipe 10, and the indoor unit side heat exchangers 7b, 7c. , 7d, and heat exchange with indoor air to condense and become a high-temperature and high-pressure liquid refrigerant. The liquid refrigerant that has exited the indoor heat exchangers 7b, 7c, and 7d is slightly decompressed by the first expansion devices 7b, 7c, and 7d that are almost fully open during heating, and the second expansion is made through the liquid-side connection refrigerant pipe 9. The device 6 is reached, where it is throttled to a low-pressure gas-liquid two-phase state. The low-pressure gas-liquid two-phase refrigerant flows into the heat source machine side heat exchanger 3, exchanges heat with air and the like, and gasifies, and returns to the compressor 1 through the switching valve 2 and the accumulator 4. The refrigerating machine oil inside the accumulator 4 returns to the compressor 1 through the oil return hole 5 together with the liquid refrigerant.
[0037]
Further, part of the liquid refrigerant that has passed through the first expansion devices 8a, 8b, 8c and the liquid-side connection refrigerant pipe 9 in the fully opened state flows into the bypass circuit 15 from the indoor unit-side heat exchangers 7b, 7c, 7d. In the bypass circuit 15, after passing through the dryer 16, the pressure is reduced to a low pressure by the third expansion device 17 to become a low-temperature low-pressure gas-liquid two-phase refrigerant. The low-temperature and low-pressure gas-liquid two-phase refrigerant includes a high-temperature and high-pressure liquid refrigerant that has exited the liquid-side connection refrigerant pipe 9 in the bypass heat exchanger 18b, and a low-pressure that has been squeezed by the second expansion device 6 in the bypass heat exchanger 18a. The gas-liquid two-phase refrigerant is heat exchanged, gasified, and merged with the refrigerant that has passed through the heat source unit side heat exchanger 3 between the switching valve 2 and the compressor 1, and returns to the compressor 1. On the other hand, the liquid refrigerant exiting the liquid side connection refrigerant pipe 9 is cooled by the second bypass heat exchanger 18b, and the temperature of the liquid refrigerant flowing into the bypass circuit 15 is lower than that of the liquid refrigerant exiting the liquid side connection refrigerant pipe 9. And the refrigerant | coolant which flows in into the 2nd expansion device 6 can ensure a liquid state, and the stable driving | operation is possible.
[0038]
Next, the operation of the dryer 16 will be described. The moisture contained in the refrigerant / refrigeration oil discharged from the compressor 1 does not change until reaching the starting point of the bypass circuit 15 as long as it is below the saturation upper limit. From this point, in the main refrigerant circuit leading to the junction with the bypass circuit 15 through the switching valve 2 via the indoor heat exchangers 7b, 7c, and 7d during cooling and through the heat source unit heat exchanger 3 during heating. Thereafter, the moisture contained in the refrigerant / refrigerant oil does not change. On the other hand, in the bypass circuit 15, when the refrigerant / refrigerant oil flows into the dryer 16, the moisture is absorbed there, and the moisture content in the refrigerant / refrigerant oil decreases downstream of the dryer 16. The refrigerant / refrigerant oil flowing through the bypass circuit 15 between the switching valve 2 and the compressor 1 and the refrigerant / refrigerant oil flowing through the main refrigerant circuit are merged. The moisture contained in the refrigerant / refrigerant oil flowing through the bypass circuit 15 is mixed with the moisture contained in the refrigerant / refrigerant oil flowing through the main refrigerant circuit, and the combined moisture is greater than the amount of water contained in the refrigerant / refrigerant oil flowing through the main refrigerant circuit. The amount decreases at that concentration. That is, moisture is absorbed by the dryer 16 in the bypass circuit 15 and the moisture content in the refrigerant circuit is reduced.
[0039]
In this embodiment, the moisture adsorption rate is slower than in the case where a dryer is provided in the main refrigerant circuit, but the rate of hydrolysis degradation of the polyester oil is also slow, so the moisture of the dryer 16 in the middle of the bypass circuit 15 piping. Hydrolysis is sufficiently suppressed by the adsorption ability, and sludge component generation in the compressor 1 can be suppressed. Moreover, by providing the dryer 16 in the middle of the piping of the bypass circuit 15, the impact of the refrigerant flow flowing through the dryer 16 can be reduced, and the dryer 16 is less likely to be crushed. Further, since the refrigerant flowing into the dryer 16 is cooled by the first and second bypass heat exchangers 18a and 18b, the refrigerant flows into the dryer 16 even when the compressor 1 is started up or during a transient operation such as defrosting. It is easy to make the refrigerant to be in a liquid state, and the dryer 16 becomes more difficult to pulverize. Further, when the temperature of the refrigerant is low, the water saturation solubility in the refrigerant is low, and in the coexistence with the dryer, moisture is more easily transferred to the dryer than in the refrigerant, and the moisture adsorption capacity of the dryer is increased. Therefore, when the temperature of the refrigerant flowing into the dryer 16 is lowered, the moisture adsorption amount of the dryer 16 is increased accordingly, and hydrolysis of the refrigerating machine oil can be suppressed.
[0040]
Embodiment 2. FIG.
A second embodiment of the present invention will be described below with reference to FIG. FIG. 2 is a refrigerant circuit diagram of the air-conditioning apparatus according to the second embodiment. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 The return hole, 6 is the second expansion device, 7b, 7c and 7d are indoor unit side heat exchangers, 8b, 8c and 8d are the first expansion device, 9 is the liquid side connection refrigerant pipe, and 10 is the gas side connection refrigerant. The piping is the same as the conventional example shown in FIG.
[0041]
15 is a bypass circuit that branches from between the second expansion device 6 and the liquid side connection refrigerant pipe 9, and the other end is connected to the refrigerant pipe between the switching valve 2 and the compressor 1, and 16 is a bypass circuit 15. A dryer provided in the middle of the piping, 17 is a third throttle device provided downstream of the dryer 16 in the middle of the bypass circuit 15, and 18 is a portion upstream of the dryer 16 of the bypass circuit 15, the switching valve 2 and the accumulator. The bypass heat exchanger for exchanging heat with the portion between the heat exchanger 4 and the first temperature detecting means 19 provided in the upstream portion of the expansion device 17 in the middle of the piping of the bypass circuit 15, and 20 of the bypass circuit 15 Second temperature detection means 21 provided downstream of the expansion device 17 in the middle of the pipe, 21 is suction pressure detection means provided in a portion between the switching valve 2 and the compressor 1.
[0042]
Next, the flow of the refrigerant will be described with reference to the drawings. A main refrigerant comprising the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the second expansion device 6, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d. Since the refrigerant flow during cooling and heating of the circuit is exactly the same as in the first embodiment, the description thereof will be omitted, and the refrigerant flow in the bypass circuit 15 will be described.
[0043]
The first expansion devices 8a, 8b, and 8c that are fully opened from the indoor unit side heat exchangers 7b, 7c, and 7d when passing through the fully expanded second expansion device 6 from the heat source device side heat exchanger 3 during cooling. Then, a part of the liquid refrigerant that has passed through the liquid side connection refrigerant pipe 9 flows into the bypass circuit 15. The liquid refrigerant that has flowed into the bypass circuit 15 undergoes heat exchange with the low-temperature and low-pressure refrigerant that has passed through the switching valve 2 in the bypass heat exchanger 18, and the temperature is lowered. It becomes a low-temperature and low-pressure gas-liquid two-phase refrigerant. The low-temperature and low-pressure gas-liquid two-phase refrigerant merges with the refrigerant in the main refrigerant circuit that has passed through the switching valve 2 between the switching valve 2 and the accumulator 4, and is separated into gas and liquid by the accumulator 4 and returns to the compressor 1.
[0044]
Next, the operation of the dryer 16 will be described. The moisture contained in the refrigerant / refrigeration oil discharged from the compressor 1 does not change until reaching the starting point of the bypass circuit 15 as long as it is below the saturation upper limit. From this point, in the main refrigerant circuit leading to the junction with the bypass circuit 15 through the switching valve 2 via the indoor heat exchangers 7b, 7c, and 7d during cooling and through the heat source unit heat exchanger 3 during heating. Thereafter, the moisture contained in the refrigerant / refrigerant oil does not change. On the other hand, in the bypass circuit 15, when the refrigerant / refrigerant oil flows into the dryer 16, the moisture is absorbed there, and the moisture content in the refrigerant / refrigerant oil decreases downstream of the dryer 16. The refrigerant / refrigerant oil flowing through the bypass circuit 15 between the switching valve 2 and the compressor 1 and the refrigerant / refrigerant oil flowing through the main refrigerant circuit are merged. The moisture contained in the refrigerant / refrigerant oil flowing through the bypass circuit 15 is mixed with the moisture contained in the refrigerant / refrigerant oil flowing through the main refrigerant circuit, and the combined moisture is greater than the amount of water contained in the refrigerant / refrigerant oil flowing through the main refrigerant circuit. The amount decreases at that concentration. That is, moisture is absorbed by the dryer 16 in the bypass circuit 15 and the moisture content in the refrigerant circuit is reduced.
[0045]
Even in this embodiment, the moisture adsorption rate is slower than the case where a dryer is provided in the main refrigerant circuit, but the rate of hydrolysis degradation of the polyester oil is also slow, so the moisture of the dryer 16 in the middle of the bypass circuit 15 piping. Hydrolysis is sufficiently suppressed by the adsorption ability, and sludge component generation in the compressor 1 can be suppressed. Moreover, by providing the dryer 16 in the middle of the piping of the bypass circuit 15, the impact of the refrigerant flow flowing through the dryer 16 can be reduced, and the dryer 16 is less likely to be crushed. Furthermore, since the refrigerant flowing into the dryer 16 is cooled by the bypass heat exchanger 18, the refrigerant flowing into the dryer 16 can be easily put into a liquid state even when the compressor 1 is started or during a transient operation such as defrosting. The dryer 16 becomes more difficult to grind. Further, when the temperature of the refrigerant is low, the water saturation solubility in the refrigerant is low, and in the coexistence with the dryer, moisture is more easily transferred to the dryer than in the refrigerant, and the moisture adsorption capacity of the dryer is increased. Therefore, when the temperature of the refrigerant flowing into the dryer 16 is lowered, the moisture adsorption amount of the dryer 16 is increased accordingly, and hydrolysis of the refrigerating machine oil can be suppressed.
[0046]
Embodiment 3 FIG.
A third embodiment of the present invention will be described below with reference to FIG. FIG. 3 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 3. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 The return hole, 6 is the second expansion device, 7b, 7c and 7d are indoor unit side heat exchangers, 8b, 8c and 8d are the first expansion device, 9 is the liquid side connection refrigerant pipe, and 10 is the gas side connection refrigerant. The piping is the same as the conventional example shown in FIG.
[0047]
15 is a bypass circuit that branches from between the second expansion device 6 and the liquid side connection refrigerant pipe 9, and the other end is connected to the refrigerant pipe between the switching valve 2 and the compressor 1, and 16 is a bypass circuit 15. A dryer provided in the middle of the piping, 17 is a third expansion device provided downstream of the dryer 16 in the middle of the bypass circuit 15, and 18 is a heat source side heat exchange with a portion of the bypass circuit 15 upstream of the dryer 16. A bypass heat exchanger for exchanging heat with a part of the air flowing into the lowermost portion of the cooler 3, 19 is a first temperature detection means provided in a portion upstream of the expansion device 17 in the middle of the piping of the bypass circuit 15. , 20 is a second temperature detecting means provided downstream of the expansion device 17 in the middle of the bypass circuit 15, and 21 is a suction pressure detecting means provided in a portion between the switching valve 2 and the compressor 1. .
[0048]
Next, the flow of the refrigerant will be described with reference to the drawings. A main refrigerant comprising the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the second expansion device 6, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d. Since the refrigerant flow during cooling and heating of the circuit is exactly the same as in the first embodiment, the description thereof will be omitted, and the refrigerant flow in the bypass circuit 15 will be described.
[0049]
The first expansion devices 8a, 8b, and 8c that are fully opened from the indoor unit side heat exchangers 7b, 7c, and 7d when passing through the fully expanded second expansion device 6 from the heat source device side heat exchanger 3 during cooling. Then, a part of the liquid refrigerant that has passed through the liquid side connection refrigerant pipe 9 flows into the bypass circuit 15. The liquid refrigerant flowing into the bypass circuit 15 exchanges heat with a part of the air flowing into the lowermost part of the heat source unit side heat exchanger 3 by the bypass heat exchanger 18, and the temperature is lowered. The pressure reducing device 17 reduces the pressure to a low pressure and becomes a low-temperature low-pressure gas-liquid two-phase refrigerant. The low-temperature and low-pressure gas-liquid two-phase refrigerant merges with the refrigerant in the main refrigerant circuit that has passed through the switching valve 2 between the switching valve 2 and the accumulator 4, and is separated into gas and liquid by the accumulator 4 and returns to the compressor 1.
In addition, in the lowest part of the heat source apparatus side heat exchanger 3 provided with the bypass heat exchanger 18 that becomes an evaporator at the time of heating, it is difficult for wind to pass through the drain flow from the upper part, and frost is generated and is likely to grow. It is warmed by the bypass heat exchanger 18 and hardly forms frost.
[0050]
Also in the third embodiment, a dryer 16 that absorbs moisture is provided in the bypass circuit 15, and the refrigerant flowing into the dryer 16 is cooled by the bypass heat exchanger 18, so that the refrigerant circuit is the same as in the first and second embodiments. The moisture content therein decreases, hydrolysis of the refrigerating machine oil can be suppressed, and pulverization of the dryer 16 by the refrigerant flow can be prevented.
[0051]
Embodiment 4 FIG.
A fourth embodiment of the present invention will be described below with reference to FIG. FIG. 4 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 4. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 The return hole, 6 is the second expansion device, 7b, 7c and 7d are indoor unit side heat exchangers, 8b, 8c and 8d are the first expansion device, 9 is the liquid side connection refrigerant pipe, and 10 is the gas side connection refrigerant. The piping is the same as the conventional example shown in FIG.
[0052]
Reference numeral 15 denotes a bypass circuit that branches from between the discharge portion of the compressor 1 and the switching valve 2, and the other end is connected to a refrigerant pipe between the switching valve 2 and the compressor 1. The provided dryer, 17 is a third throttle device provided downstream of the dryer 16 in the middle of the bypass circuit 15, and 18 is a portion of the bypass circuit 15 upstream of the dryer 16 and the third throttle of the bypass circuit 15. A bypass heat exchanger that exchanges heat with a portion downstream from the device 17, 19 is a first temperature detection means provided in a portion upstream of the expansion device 17 in the middle of the piping of the bypass circuit 15, and 20 is a piping of the bypass circuit 15. A second temperature detecting means 21 provided downstream from the throttle device 17 on the way, 21 is a second pressure detecting means provided in a portion between the switching valve 2 and the compressor 1.
[0053]
Next, the flow of the refrigerant will be described with reference to the drawings. A main refrigerant comprising the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the second expansion device 6, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d. Since the refrigerant flow during cooling and heating of the circuit is exactly the same as in the first embodiment, the description thereof will be omitted, and the refrigerant flow in the bypass circuit 15 will be described.
[0054]
In both cases of cooling and heating, part of the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the bypass circuit 15. The high-temperature and high-pressure gas refrigerant flowing into the bypass circuit 15 exchanges heat with the low-pressure refrigerant on the downstream side in the bypass heat exchanger 18 to lower the temperature and liquefy, and after passing through the dryer 16, the third expansion device 17. Then, the pressure is reduced to a low pressure to become a low-temperature low-pressure gas-liquid two-phase refrigerant, and the bypass heat exchanger 18 exchanges heat with the high-pressure side refrigerant for gasification. This low-temperature and low-pressure gas refrigerant merges with the refrigerant in the main refrigerant circuit that has passed through the switching valve 2 between the switching valve 2 and the accumulator 4, and is separated into gas and liquid by the accumulator 4 and returns to the compressor 1.
[0055]
Also in the fourth embodiment, a dryer 16 that absorbs moisture is provided in the bypass circuit 15, and the refrigerant flowing into the dryer 16 is cooled by the bypass heat exchanger 18. Therefore, as in the first, second, and third embodiments. The moisture content in the refrigerant circuit decreases, hydrolysis of the refrigerating machine oil can be suppressed, and the dryer 16 can be prevented from being crushed by the refrigerant flow.
In the fourth embodiment, since the cycle from the compressor 1 through the bypass circuit 15 to the compressor 1 is very short, the response time is good, and the time during which the liquid is not supplied to the dryer is in a transient state. It is very short and the dryer 16 is difficult to grind. Further, since this cycle does not include the liquid-side connecting refrigerant pipe 9 and the gas-side connecting refrigerant pipe 10, oxidation that occurs when sufficient non-oxidative brazing is not performed when the pipes 9 and 10 are constructed. The scale does not flow into the dryer 16 in the bypass circuit 15, thereby eliminating the danger of blocking the flow path and crushing the dryer.
[0056]
Embodiment 5 FIG.
The fifth embodiment of the present invention will be described below with reference to FIG. FIG. 5 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 5. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 The return hole, 6 is the second expansion device, 7b, 7c and 7d are indoor unit side heat exchangers, 8b, 8c and 8d are the first expansion device, 9 is the liquid side connection refrigerant pipe, and 10 is the gas side connection refrigerant. The piping is the same as the conventional example shown in FIG.
[0057]
15 is a bypass circuit that branches from between the compressor 1 and the switching valve 2, and the other end is connected to the refrigerant pipe between the switching valve 2 and the compressor 1, and 16 is provided in the middle of the bypass circuit 15. A dryer 17 is a third expansion device provided downstream of the dryer 16 in the middle of the bypass circuit 15, and 18 is a portion of the bypass circuit 15 upstream of the dryer 16 and the lowest part of the heat source unit side heat exchanger 3. A bypass heat exchanger that exchanges heat with a part of the air flowing into the part, 19 is a first temperature detecting means provided in a part upstream of the expansion device 17 in the middle of the bypass circuit 15, and 20 is a bypass circuit 15 Reference numeral 21 denotes a second temperature detection means provided downstream from the expansion device 17 in the middle of the pipe, and reference numeral 21 denotes a second pressure detection means provided in a portion between the switching valve 2 and the compressor 1.
[0058]
Next, the flow of the refrigerant will be described with reference to the drawings. A main refrigerant comprising the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the second expansion device 6, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d. Since the refrigerant flow during cooling and heating of the circuit is exactly the same as in the first embodiment, the description thereof will be omitted, and the refrigerant flow in the bypass circuit 15 will be described.
[0059]
In both cases of cooling and heating, part of the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the bypass circuit 15. The high-temperature and high-pressure gas refrigerant that has flowed into the bypass circuit 15 exchanges heat with a part of the air that flows into the lowermost part of the heat source unit side heat exchanger 3 in the bypass heat exchanger 18 to lower the temperature and liquefy. After passing through the dryer 16, the pressure is reduced to a low pressure by the third throttling device 17, and the refrigerant in the main refrigerant circuit that has passed through the switching valve 2 is joined between the switching valve 2 and the accumulator 4, and is separated by gas-liquid separation and compressed by the accumulator 4. Return to Machine 1.
In the fifth embodiment, similarly to the third embodiment, the flow of drain from the upper part in the lowermost part of the heat source unit side heat exchanger 3 provided with the bypass heat exchanger 18 that becomes an evaporator during heating is provided. However, it is difficult for the wind to pass through and frost is generated and is likely to grow, but it is warmed by the bypass heat exchanger 18 and is difficult to frost.
[0060]
Also in the fifth embodiment, a dryer 16 that absorbs moisture is provided in the bypass circuit 15, and the refrigerant flowing into the dryer 16 is cooled by the bypass heat exchanger 18, so that the refrigerant circuit is the same as in the first to fourth embodiments. The moisture content therein decreases, hydrolysis of the refrigerating machine oil can be suppressed, and pulverization of the dryer 16 by the refrigerant flow can be prevented.
Further, as in the fourth embodiment, since the cycle from the compressor 1 through the bypass circuit 15 to the compressor 1 is very short, the response time is good, and the transition time in which no liquid is supplied to the dryer is reached. It is very short and the dryer 16 is difficult to grind. Further, since this cycle does not include the liquid-side connecting refrigerant pipe 9 and the gas-side connecting refrigerant pipe 10, oxidation that occurs when sufficient non-oxidative brazing is not performed when the pipes 9 and 10 are constructed. The scale does not flow into the dryer 16 in the bypass circuit 15, thereby eliminating the danger of blocking the flow path and crushing the dryer.
[0061]
Embodiment 6 FIG.
A sixth embodiment of the present invention will be described below with reference to FIG. FIG. 6 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 6. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 The return hole, 6 is the second expansion device, 7b, 7c and 7d are indoor unit side heat exchangers, 8b, 8c and 8d are the first expansion device, 9 is the liquid side connection refrigerant pipe, and 10 is the gas side connection refrigerant. The piping is the same as the conventional example shown in FIG.
[0062]
15 is a bypass circuit that branches from between the compressor 1 and the switching valve 2, and the other end is connected to the refrigerant pipe between the switching valve 2 and the compressor 1, and 16 is provided in the middle of the bypass circuit 15. A dryer 17 is a third expansion device provided downstream of the dryer 16 in the middle of the bypass circuit 15, and 18 a is a portion upstream of the dryer 16 of the bypass circuit 15 and the lowest part of the heat source unit side heat exchanger 3. A first bypass heat exchanger 18b that exchanges heat with a part of the air flowing into the part, a part between the first bypass heat exchanger 18a of the bypass circuit 15 and the dryer 16, and a third throttle A second bypass heat exchanger that exchanges heat with a portion downstream from the device 17, 19 is a first temperature detection means provided at a portion upstream of the expansion device 17 in the middle of the piping of the bypass circuit 15, and 20 is a bypass circuit. 15 pipes in the middle Second temperature detecting means provided from the downstream expansion device 17, 21 is a second pressure detecting means provided in the portion between the switching valve 2 and the compressor 1.
[0063]
Next, the flow of the refrigerant will be described with reference to the drawings. A main refrigerant comprising the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the second expansion device 6, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d. Since the refrigerant flow during cooling and heating of the circuit is exactly the same as in the first embodiment, the description thereof will be omitted, and the refrigerant flow in the bypass circuit 15 will be described.
[0064]
In both cases of cooling and heating, part of the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the bypass circuit 15. The high-temperature and high-pressure gas refrigerant that has flowed into the bypass circuit 15 exchanges heat with a part of the air that flows into the lowermost part of the heat source unit side heat exchanger 3 in the first bypass heat exchanger 18a, and the temperature decreases. The refrigerant is liquefied and exchanges heat with the downstream low-pressure side refrigerant in the second bypass heat exchanger 18b to further reduce the temperature of the refrigerant. Thereafter, after passing through the dryer 16, the pressure is reduced to a low pressure by the third expansion device 17 to become a low-temperature and low-pressure gas-liquid two-phase refrigerant, and heat is exchanged with the high-pressure side refrigerant in the bypass heat exchanger 18. It merges with the refrigerant of the main refrigerant circuit that has passed through the switching valve 2 with the accumulator 4, and is separated into gas and liquid by the accumulator 4 and returns to the compressor 1.
In the sixth embodiment, as in the third embodiment, in the lowermost part of the heat source unit side heat exchanger 3 provided with the first bypass heat exchanger 18a, which is an evaporator during heating, from the top. Although the wind does not easily pass through the drain flow and frost is generated and is likely to grow, it is heated by the bypass heat exchanger 18 and is difficult to frost.
[0065]
Also in the sixth embodiment, a dryer 16 that absorbs moisture is provided in the bypass circuit 15, and the refrigerant flowing into the dryer 16 is cooled by the bypass heat exchangers 18a and 18b. Therefore, as in the first to fifth embodiments. The moisture content in the refrigerant circuit decreases, hydrolysis of the refrigerating machine oil can be suppressed, and the dryer 16 can be prevented from being crushed by the refrigerant flow.
Further, as in the fourth and fifth embodiments, the cycle from the compressor 1 through the bypass circuit 15 to the compressor 1 is very short, so that the response is good and the liquid is not supplied to the dryer. The time is very short and the dryer 16 is difficult to grind. Further, since this cycle does not include the liquid-side connecting refrigerant pipe 9 and the gas-side connecting refrigerant pipe 10, oxidation that occurs when sufficient non-oxidative brazing is not performed when the pipes 9 and 10 are constructed. The scale does not flow into the dryer 16 in the bypass circuit 15, thereby eliminating the danger of blocking the flow path and crushing the dryer.
[0066]
Embodiment 7 FIG.
A seventh embodiment of the present invention will be described below with reference to FIGS. 1 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 7, FIG. 7 is a block diagram relating to composition calculation of the air-conditioning apparatus according to Embodiment 7, and FIG. 8 shows the operation of the composition calculation means. It is a flow chart. Although FIG. 2 to FIG. 6 are different in the position, configuration, and refrigerant flow of the bypass circuit 15, the seventh embodiment is applied as in FIG. Further, a hydrofluorocarbon mixed refrigerant is used as the working medium in this embodiment.
[0067]
In the figure, reference numeral 19 denotes a first temperature detecting means which is provided in a portion upstream of the expansion device 17 in the middle of the bypass circuit 15 and detects the temperature of the high-temperature and high-pressure liquid refrigerant at the inlet of the third expansion device 17. Is provided downstream of the expansion device 17 in the middle of the bypass circuit 15 and upstream of the first and second bypass heat exchangers 18a and 18b, and is a low-temperature and low-pressure gas-liquid at the outlet of the third expansion device 17. Second temperature detecting means for detecting the temperature of the two-phase refrigerant, 21 is second pressure detecting means provided in a portion between the switching valve 2 and the compressor 1, and 22 is first temperature detecting means 19. The composition calculation means calculates the composition of the mixed refrigerant based on the detection values of the second temperature detection means 20 and the second pressure detection means 21.
[0068]
Next, the composition calculation operation will be described with reference to FIG. First, in step 100, the composition Xi is assumed for each component of the mixed refrigerant. In step 101, the detected values T1, T2, and P2 are detected from the first temperature detecting means 19, the second temperature detecting means 20, and the suction pressure detecting means 21, respectively. In step 102, a high-pressure liquid enthalpy H1 is calculated from the circulation composition Xi assumed in step 100 and the detected value T1 of the first temperature detecting means 19. In step 103, a low-pressure two-phase enthalpy H2 is calculated from the circulation composition Xi, the detection value T2 of the second temperature detection means 20 and the detection value P2 of the suction pressure detection means 21. In step 104, the above H1 and H2 are compared, and the circulation composition assumption is repeated until they are equal. As a result, the value of Xi when H1 and H2 become equal is calculated as the circulation composition. Here, the subscript i indicates that the refrigerant is a mixture of i components.
[0069]
Embodiment 8 FIG.
The eighth embodiment of the present invention will be described below with reference to FIG. FIG. 9 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 8. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 Return holes 7b, 7c and 7d are indoor unit side heat exchangers, 8b, 8c and 8d are first expansion devices, 9 is a liquid side connection refrigerant pipe, 10 is a gas side connection refrigerant pipe, and the above is shown in FIG. This is similar to the conventional example shown. An oil separator 23 is provided between the discharge portion of the compressor 1 and the switching valve 2 and separates the refrigeration oil discharged from the compressor 1 together with the refrigerant from the gas refrigerant, and 24 is switched to the bottom portion of the oil separator 23. An oil return bypass circuit connecting the valve 2 and the suction part of the compressor 1 and returning the separated refrigeration oil to the suction part of the compressor 1, and 25 is a fourth part provided in the middle of the piping of the oil return bypass circuit 24. It is an aperture device.
[0070]
Next, the flow of the refrigerant will be described with reference to the drawings. First, at the time of cooling, the gas refrigerant compressed to high temperature and high pressure by the compressor 1 flows into the heat source machine side heat exchanger 3 through the switching valve 2, and is condensed by exchanging heat with air and the like. Becomes a refrigerant. Furthermore, the liquid side connecting refrigerant pipe 9 is passed through to the indoor units B, C, D, and the first control is performed so that the degree of superheat at the outlets of the indoor unit side heat exchangers 7b, 7c, 7d is within a certain range. The throttling devices 8b, 8c, and 8d are throttled to a low-pressure gas-liquid two-phase state. The low-pressure gas-liquid two-phase refrigerant flows into the indoor unit side heat exchangers 7b, 7c, and 7d, exchanges heat with indoor air and gasifies, and forms the gas side connection refrigerant pipe 10, the switching valve 2, and the accumulator 4. It returns to the compressor 1 through this. The refrigerating machine oil inside the accumulator 4 returns to the compressor 1 through the oil return hole 5 together with the liquid refrigerant.
[0071]
At the time of heating, the gas refrigerant compressed to high temperature and high pressure by the compressor 1 reaches the indoor units B, C, D through the switching valve 2 and the gas side connection refrigerant pipe 10, and the indoor unit side heat exchangers 7b, 7c. , 7d, and heat exchange with indoor air to condense and become a high-temperature and high-pressure liquid refrigerant. The liquid refrigerant that has exited the indoor heat exchangers 7b, 7c, and 7d is throttled to the low-pressure gas-liquid two-phase state by the first expansion devices 8b, 8c, and 8d, and the low-pressure gas-liquid two-phase refrigerant is connected to the liquid side. It flows into the heat source machine side heat exchanger 3 through the refrigerant pipe 9, exchanges heat with air and gasifies, and returns to the compressor 1 through the switching valve 2 and the accumulator 4. The refrigerating machine oil inside the accumulator 4 returns to the compressor 1 through the oil return hole 5 together with the liquid refrigerant.
[0072]
In both cases of cooling and heating, the low-temperature and low-pressure gas refrigerant sucked into the compressor 1 is compressed to become high-temperature and high-pressure gas refrigerant and discharged from the compressor 1. At this time, a part of the refrigerating machine oil inside the compressor 1 is also discharged and flows into the oil separator 23 together with the gas refrigerant, where it is separated from the gas refrigerant. The gas refrigerant separated by the oil separator 23 flows to the switching valve 2, and the refrigerating machine oil flows into the oil return bypass circuit 24. The refrigerating machine oil that has flowed into the oil return bypass circuit 24 is decompressed to a low pressure by the fourth expansion device 25, and joins the refrigerant in the main refrigerant circuit that has passed through the switching valve 2 between the switching valve 2 and the accumulator 4. Since the refrigerating machine oil is separated at the discharge part of the compressor 1 in this way, the circulation flow rate ratio of the refrigerating machine oil in the main refrigerant circuit is very low, and the first expansion device 8b in the indoor units B, C, D, The flow rate of the refrigerating machine oil flowing through 8c and 8d is significantly reduced.
[0073]
Moreover, the refrigerating machine oil degradation product produced | generated by the sliding part of the compressor 1 exists as a solid in a refrigerating machine oil, or melt | dissolves and exists. When the refrigerant is discharged from the compressor 1, it is mixed with the refrigerating machine oil and discharged into the discharge gas, but is separated by the oil separator 23 and does not flow into the main refrigerant circuit, so the indoor units B, C, D The flow rate of the refrigerating machine oil flowing through the first throttling devices 8b, 8c, and 8d inside is remarkably reduced, and the integrated flow rate of the deteriorated refrigerating machine oil circulating with the refrigerating machine oil is also reduced. As a result, the amount of the refrigeration oil deteriorated material that becomes sludge and adheres to the first expansion devices 8b, 8c, 8d can be reduced, and a shortage of the flow of the first expansion devices 8b, 8c, 8d can be avoided. There is no shortage of capability, and reliability is significantly improved.
[0074]
Embodiment 9 FIG.
A ninth embodiment of the present invention will be described below with reference to FIG. FIG. 10 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 9. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 Return holes, 7b, 7c, 7d are indoor unit side heat exchangers, 8b, 8c, 8d are first expansion devices, 9 is a liquid side connection refrigerant pipe, 10 is a gas side connection refrigerant pipe, 23 is an oil separator, Reference numeral 24 denotes an oil return bypass circuit, and reference numeral 25 denotes a fourth throttling device. The above is the same as in the eighth embodiment shown in FIG. 26 is a sludge filter provided in the upstream part of the 4th expansion device 25 in the middle of piping of the oil return bypass circuit 24.
[0075]
Next, the flow of refrigerant and refrigerating machine oil will be described with reference to the drawings. During cooling and heating of the main refrigerant circuit including the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d Since the refrigerant flow and the operation of the oil separator 23 are exactly the same as those in the eighth embodiment, the description thereof will be omitted, and the flow of the refrigerating machine oil in the oil return bypass circuit 24 will be described. The refrigerating machine oil separated by the oil separator 23 flows into the oil return bypass circuit 24, passes through the sludge filter 26, is reduced to a low pressure by the fourth expansion device 25, and is switched between the switching valve 2 and the accumulator 4. It merges with the refrigerant in the main refrigerant circuit that has passed through the valve 2.
[0076]
Moreover, the refrigerating machine oil degradation product produced | generated by the sliding part of the compressor 1 is mixed with discharge gas with refrigerating machine oil, is discharged in a refrigerant circuit, is isolate | separated with refrigerating machine oil with the oil separator 23, and the oil return bypass circuit 24 In the sludge filter 26. Therefore, the content of the refrigeration oil deterioration product in the refrigeration oil that flows into the accumulator 4 and returns to the compressor 1 decreases, and the amount of sludge that adheres to the oil return hole 5 decreases. As a result, the refrigerating machine oil in the compressor 1 is not exhausted, and an abnormal high pressure rise / low pressure drop and a discharge gas temperature rise caused thereby can be avoided, and the reliability is remarkably improved. The cycle in which the refrigerant discharged from the compressor 1 returns to the compressor 1 through the oil return bypass circuit 24 does not pass through the liquid side connection refrigerant pipe 9 and the gas side connection refrigerant pipe 10 in the middle. Therefore, the oxidation scale generated when the non-oxidizing brazing is not sufficiently performed during the construction of the liquid side connecting refrigerant pipe 9 and the gas side connecting refrigerant pipe 10 may flow into the sludge filter 26 during operation. There is no danger of blocking the flow path or deforming or destroying the sludge filter.
[0077]
Embodiment 10 FIG.
The tenth embodiment of the present invention will be described below with reference to FIG. FIG. 11 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 10. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 Return holes, 7b, 7c, 7d are indoor unit side heat exchangers, 8b, 8c, 8d are first expansion devices, 9 is a liquid side connection refrigerant pipe, 10 is a gas side connection refrigerant pipe, 23 is an oil separator, 24 is an oil return bypass circuit, 25 is a fourth throttling device, 26 is a sludge filter, and the above is the same as in the ninth embodiment shown in FIG. A bypass heat exchanger 27 exchanges heat between a portion upstream of the sludge filter 26 of the oil return bypass circuit 24 and a part of the air flowing into the lowermost portion of the heat source unit side heat exchanger 3.
[0078]
Next, the flow of refrigerant and refrigerating machine oil will be described with reference to the drawings. During cooling and heating of the main refrigerant circuit including the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d Since the refrigerant flow and the operation of the oil separator 23 are exactly the same as those in the eighth embodiment, the description thereof will be omitted, and the flow of the refrigerating machine oil in the oil return bypass circuit 24 will be described. The refrigerating machine oil separated by the oil separator 23 flows into the oil return bypass circuit 24, and heat is exchanged with a part of the air flowing into the lowermost part of the heat source apparatus side heat exchanger 3 by the bypass heat exchanger 27, so that the temperature becomes Then, the pressure is reduced to a low pressure by the fourth throttling device 25 through the sludge filter 26 and joins the refrigerant in the main refrigerant circuit passing through the switching valve 2 between the switching valve 2 and the accumulator 4.
In the tenth embodiment, as in the third, fifth and sixth embodiments, in the lowermost part of the heat source unit side heat exchanger 3 provided with the bypass heat exchanger 18 which becomes an evaporator during heating, from the top. However, it is difficult for the wind to pass through the drain flow and frost is generated and grows easily, but it is warmed by the bypass heat exchanger 18 and is difficult to frost.
[0079]
Moreover, the refrigerating machine oil degradation product produced | generated by the sliding part of the compressor 1 is mixed with discharge gas with refrigerating machine oil, is discharged in a refrigerant circuit, is isolate | separated with refrigerating machine oil with the oil separator 23, and the oil return bypass circuit 24 In the sludge filter 26. Moreover, by passing through the bypass heat exchanger 27, the temperature of the refrigerating machine oil decreases, and the concentration of the refrigerant in the refrigerating machine oil increases. Thereby, the refrigerating machine oil degradation product which melted in refrigerating machine oil precipitates, and what was originally melted in refrigerating machine oil can also be caught in sludge filter 26. Therefore, the content of the refrigeration oil deterioration product in the refrigeration oil that flows into the accumulator 4 and returns to the compressor 1 is further reduced, and the amount of sludge adhering to the oil return hole 5 is reduced. As a result, the refrigerating machine oil in the compressor 1 is not exhausted, and an abnormal high pressure rise / low pressure drop and a discharge gas temperature rise caused thereby can be avoided, and the reliability is remarkably improved. The cycle in which the refrigerant discharged from the compressor 1 returns to the compressor 1 through the oil return bypass circuit 24 does not pass through the liquid side connection refrigerant pipe 9 and the gas side connection refrigerant pipe 10 in the middle. Therefore, the liquid side connection refrigerant pipe 9 and the gas
Oxidation scale generated when sufficient non-oxidizing brazing is not performed at the time of construction of the side connection refrigerant pipe 10 does not flow into the sludge filter 26 during operation, and the flow path is blocked or sludge There is no risk of deformation or destruction of the filter.
[0080]
Embodiment 11 FIG.
The eleventh embodiment of the present invention will be described below with reference to FIG. FIG. 12 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 11. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 Return holes, 7b, 7c, 7d are indoor unit side heat exchangers, 8b, 8c, 8d are first expansion devices, 9 is a liquid side connection refrigerant pipe, 10 is a gas side connection refrigerant pipe, 23 is an oil separator, 24 is an oil return bypass circuit, 25 is a fourth throttling device, 26 is a sludge filter, and the above is the same as in the ninth embodiment shown in FIG. A bypass heat exchanger 27 exchanges heat between a portion upstream of the sludge filter 26 of the oil return bypass circuit 24 and a portion between the switching valve 2 and the accumulator 4.
[0081]
Next, the flow of refrigerant and refrigerating machine oil will be described with reference to the drawings. During cooling and heating of the main refrigerant circuit including the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d Since the refrigerant flow and the operation of the oil separator 23 are exactly the same as those in the eighth embodiment, the description thereof will be omitted, and the flow of the refrigerating machine oil in the oil return bypass circuit 24 will be described. The refrigerating machine oil separated in the oil separator 23 flows into the oil return bypass circuit 24, and in the bypass heat exchanger 27, heat is exchanged with the low-temperature and low-pressure refrigerant that returns to the compressor 1 through the switching valve 2, and the temperature decreases. Through the sludge filter 26, the pressure is reduced to a low pressure by the fourth throttling device 25, and the refrigerant in the main refrigerant circuit passing through the switching valve 2 is joined between the switching valve 2 and the accumulator 4.
[0082]
Moreover, the refrigerating machine oil degradation product produced | generated by the sliding part of the compressor 1 is mixed with discharge gas with refrigerating machine oil, is discharged in a refrigerant circuit, is isolate | separated with refrigerating machine oil with the oil separator 23, and the oil return bypass circuit 24 In the sludge filter 26. Moreover, by passing through the bypass heat exchanger 27, the temperature of the refrigerating machine oil decreases, and the concentration of the refrigerant in the refrigerating machine oil increases. Thereby, the refrigerating machine oil degradation product which melted in refrigerating machine oil precipitates, and what was originally melted in refrigerating machine oil can also be caught in sludge filter 26. Therefore, the content of the refrigeration oil deterioration product in the refrigeration oil that flows into the accumulator 4 and returns to the compressor 1 is further reduced, and the amount of sludge adhering to the oil return hole 5 is reduced. As a result, the refrigerating machine oil in the compressor 1 is not exhausted, and an abnormal high pressure rise / low pressure drop and a discharge gas temperature rise caused thereby can be avoided, and the reliability is remarkably improved. The cycle in which the refrigerant discharged from the compressor 1 returns to the compressor 1 through the oil return bypass circuit 24 does not pass through the liquid side connection refrigerant pipe 9 and the gas side connection refrigerant pipe 10 in the middle. Therefore, the oxidation scale generated when the non-oxidizing brazing is not sufficiently performed during the construction of the liquid side connecting refrigerant pipe 9 and the gas side connecting refrigerant pipe 10 may flow into the sludge filter 26 during operation. There is no danger of blocking the flow path or deforming or destroying the sludge filter.
[0083]
Embodiment 12 FIG.
A twelfth embodiment of the present invention will be described below with reference to FIG. FIG. 13 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 12. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 Return holes, 7b, 7c, 7d are indoor unit side heat exchangers, 8b, 8c, 8d are first expansion devices, 9 is a liquid side connection refrigerant pipe, 10 is a gas side connection refrigerant pipe, 23 is an oil separator, 24 is an oil return bypass circuit, 25 is a fourth throttling device, 26 is a sludge filter, and the above is the same as in the ninth embodiment shown in FIG. 28 is a liquid refrigerant injection circuit that branches from between the oil separator 23 and the switching valve 2 and joins the upstream portion of the sludge filter 26 of the oil return bypass circuit 24, and 29 is a pipe and a heat source side of the liquid refrigerant injection circuit 28. This is a liquid injection circuit heat exchanger that exchanges heat with a part of the air flowing into the lowermost part of the heat exchanger 3.
[0084]
Next, the flow of refrigerant and refrigerating machine oil will be described with reference to the drawings. During cooling and heating of the main refrigerant circuit including the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d The flow of the refrigerant and the operation of the oil separator 23 are the same as those in the eighth embodiment, so the description thereof will be omitted, and the flow of the refrigerant and the refrigerating machine oil in the oil return bypass circuit 24 and the liquid refrigerant injection circuit 28 will be described. A part of the high-temperature and high-pressure gas refrigerant from which the refrigeration oil is separated by the oil separator 23 flows into the liquid refrigerant injection circuit 28, and flows into the lowermost part of the heat source unit side heat exchanger 3 by the liquid injection circuit heat exchanger 29. It exchanges heat with a part of the air to lower the temperature and liquefy, and merges with the refrigeration oil separated by the oil separator 23 and flowing into the oil return bypass circuit 24. The combined liquid refrigerant and refrigeration oil are reduced to a low pressure by the fourth throttling device 25 through the sludge filter 26 and merge with the refrigerant in the main refrigerant circuit passing through the switching valve 2 between the switching valve 2 and the accumulator 4. To do.
In the twelfth embodiment, similarly to the third, fifth, sixth and tenth embodiments, at the lowermost part of the heat source unit side heat exchanger 3 provided with the liquid injection circuit heat exchanger 29 which becomes an evaporator during heating. However, it is difficult for the wind to pass through the drain flow from the top and frost is generated and grows easily, but it is warmed by the liquid injection circuit heat exchanger 29 and is difficult to frost.
[0085]
Moreover, the refrigerating machine oil degradation product produced | generated by the sliding part of the compressor 1 is mixed with discharge gas with a refrigerating machine oil, and is discharged in a refrigerant circuit, is isolate | separated with refrigerating machine oil with the oil separator 23, and is returned to the oil return bypass circuit 24. By flowing in and joining with the liquid refrigerant flowing out of the liquid injection circuit heat exchanger 29 of the liquid refrigerant injection circuit 28, the refrigerant concentration in the refrigerating machine oil is increased and flows into the sludge filter 26 and captured. Thereby, since the refrigerating machine oil degradation product dissolved in refrigerating machine oil precipitates, the sludge filter 26 can also capture what was originally dissolved in the refrigerating machine oil together with sludge present as a solid. Therefore, the content of the refrigeration oil deterioration product in the refrigeration oil that flows into the accumulator 4 and returns to the compressor 1 is further reduced, and the amount of sludge adhering to the oil return hole 5 is reduced. As a result, the refrigerating machine oil in the compressor 1 is not exhausted, and an abnormal high pressure rise / low pressure drop and a discharge gas temperature rise caused thereby can be avoided, and the reliability is remarkably improved. The cycle in which the refrigerant discharged from the compressor 1 returns to the compressor 1 through the oil return bypass circuit 24 does not pass through the liquid side connection refrigerant pipe 9 and the gas side connection refrigerant pipe 10 in the middle. Therefore, the oxidation scale generated when the non-oxidizing brazing is not sufficiently performed during the construction of the liquid side connecting refrigerant pipe 9 and the gas side connecting refrigerant pipe 10 may flow into the sludge filter 26 during operation. There is no danger of blocking the flow path or deforming or destroying the sludge filter.
[0086]
Embodiment 13 FIG.
A thirteenth embodiment of the present invention will be described below with reference to FIG. FIG. 14 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 13. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 Return holes, 7b, 7c, 7d are indoor unit side heat exchangers, 8b, 8c, 8d are first expansion devices, 9 is a liquid side connection refrigerant pipe, 10 is a gas side connection refrigerant pipe, 23 is an oil separator, 24 is an oil return bypass circuit, 25 is a fourth throttling device, 26 is a sludge filter, 28 is a liquid refrigerant injection circuit, and the above is the same as in the twelfth embodiment shown in FIG. This is a liquid injection circuit heat exchanger in which heat is exchanged between the piping of the refrigerant injection circuit 28 and the portion between the switching valve 2 and the accumulator 4.
[0087]
Next, the flow of refrigerant and refrigerating machine oil will be described with reference to the drawings. During cooling and heating of the main refrigerant circuit including the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d The flow of the refrigerant and the operation of the oil separator 23 are the same as those in the eighth embodiment, so the description thereof will be omitted, and the flow of the refrigerant and the refrigerating machine oil in the oil return bypass circuit 24 and the liquid refrigerant injection circuit 28 will be described. A part of the high-temperature and high-pressure gas refrigerant from which the refrigeration oil is separated by the oil separator 23 flows into the liquid refrigerant injection circuit 28, and returns to the compressor 1 through the switching valve 2 in the liquid injection circuit heat exchanger 29. It exchanges heat with the refrigerant to lower the temperature and liquefy, and merges with the refrigerating machine oil separated by the oil separator 23 and flowing into the oil return bypass circuit 24. The combined liquid refrigerant and refrigeration oil are reduced to a low pressure by the fourth throttling device 25 through the sludge filter 26 and merge with the refrigerant in the main refrigerant circuit passing through the switching valve 2 between the switching valve 2 and the accumulator 4. To do.
[0088]
Moreover, the refrigerating machine oil degradation product produced | generated by the sliding part of the compressor 1 is mixed with discharge gas with a refrigerating machine oil, and is discharged in a refrigerant circuit, is isolate | separated with refrigerating machine oil with the oil separator 23, and is returned to the oil return bypass circuit 24. By flowing in and joining with the liquid refrigerant flowing out of the liquid injection circuit heat exchanger 29 of the liquid refrigerant injection circuit 28, the refrigerant concentration in the refrigerating machine oil is increased and flows into the sludge filter 26 and captured. Thereby, since the refrigerating machine oil degradation product which melt | dissolved in refrigerating machine oil precipitates, what was originally melt | dissolved in refrigerating machine oil with the sludge which exists as a solid in the sludge filter 26 can also be capture | acquired. Therefore, the content of the refrigeration oil deterioration product in the refrigeration oil that flows into the accumulator 4 and returns to the compressor 1 is further reduced, and the amount of sludge adhering to the oil return hole 5 is reduced. As a result, the refrigerating machine oil in the compressor 1 is not exhausted, and an abnormal high pressure rise / low pressure drop and a discharge gas temperature rise caused thereby can be avoided, and the reliability is remarkably improved. The cycle in which the refrigerant discharged from the compressor 1 returns to the compressor 1 through the oil return bypass circuit 24 does not pass through the liquid side connection refrigerant pipe 9 and the gas side connection refrigerant pipe 10 in the middle. Therefore, the oxidation scale generated when the non-oxidizing brazing is not sufficiently performed during the construction of the liquid side connecting refrigerant pipe 9 and the gas side connecting refrigerant pipe 10 may flow into the sludge filter 26 during operation. There is no danger of blocking the flow path or deforming or destroying the sludge filter.
[0089]
Embodiment 14 FIG.
A fourteenth embodiment of the present invention will be described below with reference to FIG. FIG. 15 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 14. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 The return hole, 6 is the second expansion device, 7b, 7c and 7d are indoor unit side heat exchangers, 8b, 8c and 8d are the first expansion device, 9 is the liquid side connection refrigerant pipe, and 10 is the gas side connection refrigerant. The piping is the same as that of the first embodiment shown in FIG. 1, 23 is an oil separator, 24 is an oil return bypass circuit, 25 is a fourth throttling device, and 26 is a sludge filter. 28, which is the same as that of the twelfth embodiment shown in FIG. 1, branches from between the second expansion device 6 and the liquid side connection refrigerant pipe 9, and joins the upstream portion of the sludge filter 26 of the oil return bypass circuit 24. This is a liquid refrigerant injection circuit.
[0090]
Next, the flow of refrigerant and refrigerating machine oil will be described with reference to the drawings. A main refrigerant comprising the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the second expansion device 6, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d. The refrigerant flow during cooling and heating of the circuit is exactly the same as in the first embodiment, and the operation of the oil separator 23 is the same as in the eighth embodiment, so the description thereof is omitted, and the oil return bypass circuit 24 and liquid refrigerant injection are omitted. The flow of the refrigerant and the refrigerating machine oil in the circuit 28 will be described. The refrigerating machine oil separated by the oil separator 23 flows into the oil return bypass circuit 24. Further, during cooling, the liquid refrigerant that has condensed and liquefied through heat exchange with the air in the heat source unit side heat exchanger 3 and passed through the fully-opened second expansion device 6 passes through the indoor unit side heat exchangers 7b and 7c during heating. , 7d, and the liquid refrigerant that has condensed and liquefied by the heat exchange with the first throttling devices 8a, 8b, 8c and the liquid side connection refrigerant pipe 9 in the fully opened state partially flows into the liquid refrigerant injection circuit 28. The refrigerating machine oil that has flowed into the oil return bypass circuit 24 merges. The combined liquid refrigerant and refrigeration oil are reduced to a low pressure by the fourth throttling device 25 through the sludge filter 26 and merge with the refrigerant in the main refrigerant circuit passing through the switching valve 2 between the switching valve 2 and the accumulator 4. To do.
[0091]
Moreover, the refrigerating machine oil degradation product produced | generated by the sliding part of the compressor 1 is mixed with discharge gas with a refrigerating machine oil, and is discharged in a refrigerant circuit, is isolate | separated with refrigerating machine oil with the oil separator 23, and is returned to the oil return bypass circuit 24. The refrigerant flows in and merges with the liquid refrigerant flowing into the liquid refrigerant injection circuit 28, whereby the refrigerant concentration in the refrigeration oil is increased and flows into the sludge filter 26 and captured. Thereby, since the refrigerating machine oil degradation product which melt | dissolved in refrigerating machine oil precipitates, what was originally melt | dissolved in refrigerating machine oil with the sludge which exists as a solid in the sludge filter 26 can also be capture | acquired. Therefore, the content of the refrigeration oil deterioration product in the refrigeration oil that flows into the accumulator 4 and returns to the compressor 1 is further reduced, and the amount of sludge adhering to the oil return hole 5 is reduced. As a result, the refrigerating machine oil in the compressor 1 is not exhausted, and an abnormal high pressure rise / low pressure drop and a discharge gas temperature rise caused thereby can be avoided, and the reliability is remarkably improved. The cycle in which the refrigerant discharged from the compressor 1 returns to the compressor 1 through the oil return bypass circuit 24 does not pass through the liquid side connection refrigerant pipe 9 and the gas side connection refrigerant pipe 10 in the middle. Therefore, the oxidation scale generated when the non-oxidizing brazing is not sufficiently performed during the construction of the liquid side connecting refrigerant pipe 9 and the gas side connecting refrigerant pipe 10 may flow into the sludge filter 26 during operation. There is no danger of blocking the flow path or deforming or destroying the sludge filter.
[0092]
Embodiment 15 FIG.
A fifteenth embodiment of the present invention will be described below with reference to FIG. FIG. 15 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 15. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil of the accumulator 4 Return holes, 7b, 7c, 7d are indoor unit side heat exchangers, 8b, 8c, 8d are first expansion devices, 9 is a liquid side connection refrigerant pipe, 10 is a gas side connection refrigerant pipe, 23 is an oil separator, 24 is an oil return bypass circuit, 25 is a fourth throttling device, 26 is a sludge filter, and the above is the same as that of the twelfth embodiment shown in FIG. A liquid refrigerant injection circuit 28 branches from between the oil separator 23 and the switching valve 2, and the other end is connected to a refrigerant pipe between the switching valve 2 and the compressor 1, and 30 is in the middle of the liquid refrigerant injection circuit 28. The fifth expansion device 29 is a liquid injection circuit heat exchanger that exchanges heat between the upstream portion and the downstream portion of the fifth expansion device 30 of the liquid refrigerant injection circuit 28. Further, the upstream portion of the sludge filter 26 of the oil return bypass circuit 24 and the upstream portion of the fifth expansion device 30 of the liquid refrigerant injection circuit 28 are connected by piping.
[0093]
Next, the flow of refrigerant and refrigerating machine oil will be described with reference to the drawings. During cooling and heating of the main refrigerant circuit including the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d The flow of the refrigerant and the operation of the oil separator 23 are the same as those in the eighth embodiment, so the description thereof will be omitted, and the flow of the refrigerant and the refrigerating machine oil in the oil return bypass circuit 24 and the liquid refrigerant injection circuit 28 will be described. A part of the high-temperature and high-pressure gas refrigerant from which the refrigeration oil is separated by the oil separator 23 flows into the liquid refrigerant injection circuit 28, and exchanges heat with the refrigerant on the low-pressure side of the liquid refrigerant injection circuit 28 in the liquid injection circuit heat exchanger 29. The temperature is lowered and liquefied, and a part thereof flows into the fifth expansion device 30 and is depressurized to a low pressure. The liquid injection circuit heat exchanger 29 is heated and gasified by the high-pressure side refrigerant, and the switching valve 2 And the accumulator 4 merge with the refrigerant in the main refrigerant circuit that has passed through the switching valve 2. Further, the remaining refrigerant liquefied on the high pressure side of the liquid injection circuit heat exchanger 29 joins with the refrigeration oil separated by the oil separator 23 and flowing into the oil return bypass circuit 24. The combined liquid refrigerant and refrigeration oil are reduced to a low pressure by the fourth throttling device 25 through the sludge filter 26 and merge with the refrigerant in the main refrigerant circuit passing through the switching valve 2 between the switching valve 2 and the accumulator 4. To do.
[0094]
Moreover, the refrigerating machine oil degradation product produced | generated by the sliding part of the compressor 1 is mixed with discharge gas with a refrigerating machine oil, and is discharged in a refrigerant circuit, is isolate | separated with refrigerating machine oil with the oil separator 23, and is returned to the oil return bypass circuit 24. The refrigerant concentration in the refrigerating machine oil is increased to flow into the sludge filter 26 and captured by merging with a part of the liquid refrigerant flowing in from the high pressure side of the liquid injection circuit heat exchanger 29 of the liquid refrigerant injection circuit 28. Is done. Thereby, since the refrigerating machine oil degradation product which melt | dissolved in refrigerating machine oil precipitates, what was originally melt | dissolved in refrigerating machine oil with the sludge which exists as a solid in the sludge filter 26 can also be capture | acquired. Therefore, the content of the refrigeration oil deterioration product in the refrigeration oil that flows into the accumulator 4 and returns to the compressor 1 is further reduced, and the amount of sludge adhering to the oil return hole 5 is reduced. As a result, the refrigerating machine oil in the compressor 1 is not exhausted, and an abnormal high pressure rise / low pressure drop and a discharge gas temperature rise caused thereby can be avoided, and the reliability is remarkably improved. The cycle in which the refrigerant discharged from the compressor 1 returns to the compressor 1 through the oil return bypass circuit 24 does not pass through the liquid side connection refrigerant pipe 9 and the gas side connection refrigerant pipe 10 in the middle. Therefore, the oxidation scale generated when the non-oxidizing brazing is not sufficiently performed during the construction of the liquid side connecting refrigerant pipe 9 and the gas side connecting refrigerant pipe 10 may flow into the sludge filter 26 during operation. There is no danger of blocking the flow path or deforming or destroying the sludge filter.
[0095]
Embodiment 16 FIG.
FIG. 17 is a longitudinal sectional view showing an embodiment 16 of the dryer 16 used in the first to sixth embodiments. FIG. 17 (a) shows the refrigerant flow direction from left to right. ) Shows the case where the dryer is arranged so that the flow direction of the refrigerant is from bottom to top, and FIG. 7C shows the case where the dryer is arranged so that the flow direction of the refrigerant is from top to bottom. In the figure, 50 is a cylindrical container, 51 is an inflow pipe provided at one end of the container 50, 52 is an outflow pipe provided at the other end of the container 50, 53 is composed mainly of synthetic zeolite, and is made of activated alumina or the like. A dryer core 54, which is blended and hardened with a binder such as an adhesive, is a refrigerating machine oil.
[0096]
The refrigerant flowing in from the inflow pipe 51 absorbs the moisture contained in the refrigerant by the dryer core 53. However, since the refrigerant passage passes through the very fine dryer core, the larger one is here. Be captured. Some dryers have a filter provided on the upstream side or downstream side of the dryer core 53, and foreign matter is also captured by the filter portion. Therefore, a dryer having this configuration can be used as the sludge filter 26 in the ninth to fifteenth embodiments. Thus, by using a dryer as the sludge filter 26, moisture can be directly absorbed from the refrigeration oil flowing through the oil return bypass circuit 24, and the sludge filter function and the moisture capturing function can be combined. Thereby, while suppressing hydrolysis of refrigerating machine oil, the refrigerating machine oil degradation product content rate in refrigerating machine oil can also be reduced. As a result, the water content in the main refrigerant circuit and the refrigerating machine oil degradation product content rate are also reduced. The amount of sludge adhering to the expansion devices 8b, 8c, 8d, the oil return hole 5, etc. decreases.
[0097]
Moreover, when using the thing of the structure shown in FIG. 17 as the dryer 16 in Embodiments 1-6 and the sludge filter 26 in Embodiments 9-15, it installs like the figure (a) and (b). If the liquid refrigerant or the refrigerating machine oil does not accumulate in the dryer container 50 in the transient state, the liquid refrigerant or the refrigerating machine oil cannot flow out from the container 50. On the other hand, as shown in FIG. 5C, when the refrigerant is arranged so that the flow direction is from the top to the bottom, the liquid refrigerant or the refrigeration oil that has flowed into the container 50 flows out quickly, so that it is quickly stabilized. In addition, the refrigerating machine oil is not depleted from the compressor.
[0097]
Embodiment 17. FIG.
FIG. 18 is a longitudinal sectional view showing an example of the accumulator 4 according to the seventeenth embodiment used in each of the above-described embodiments. In the figure, reference numeral 60 denotes an accumulator container, and 61 denotes the inside of the container from the bottom of the container 60. An inflow pipe inserted up to the upper part, 62 is inserted from the bottom of the container 60 to the upper part in the container, and an outflow pipe provided with an oil return hole 5 for returning the refrigeration machine oil to the lower part, 63 is provided in the lower part of the container 60 The liquid mixture of the stored liquid refrigerant and the refrigerating machine oil, 64 is an oil return pipe that connects the lower space inside the container 60 and the upper pipe end of the outflow pipe 62, and 65 is the oil return pipe 64 inside the container 60. It is an orifice provided at one end on the lower space side.
[0098]
Next, the oil return operation of the accumulator 4 will be described. The difference in height between the liquid level of the mixed liquid 63 in the accumulator and the pipe end of the outflow pipe 62 is h, the flow velocity of the refrigerant in the outflow pipe is u, the density of the refrigerant flowing out of the outflow pipe is ρg, The density of the liquid 63 is ρ _l Then, the differential pressure ΔP generated before and after the orifice 65 obtained by subtracting the outlet pressure from the inlet pressure of the orifice 65 is
ΔP = k ₁ ・ Ρ _g ・ U ₂ / 2-k ₂ ・ Ρ _l ・ H
(Where k ₁ , K ₂ Is a positive constant). However, since the oil return pipe 64 is sufficiently thick, the pressure loss here is ignored. If ΔP is positive, it means that oil can be returned, and if ΔP is negative, it means that oil cannot be returned. Further, as ΔP is positive and large, the oil return flow increases.
[0099]
As is clear from this equation, when the refrigerant flow rate u is large, the first term is larger than the second term on the right side, and oil can be returned even if the liquid level is low. On the other hand, if the refrigerant flow rate u is small, the negative amount of the second term is large even if the liquid level is somewhat high, and the flow rate of the mixed liquid flowing out to the outflow pipe 64 is small. When the refrigerant flow rate is large, the ratio of the refrigerating machine oil discharged from the compressor is large, but when the refrigerant flow rate is small, the ratio of the refrigerating machine oil discharged from the compressor is small. Therefore, when the refrigerating machine oil deterioration component adheres to the oil return hole 5, the oil return is insufficient when the refrigerant flow rate is large. When the oil return hole 5 is enlarged, the oil returns sufficiently when the refrigerant flow rate is high, but when the refrigerant flow rate is low and the liquid level of the accumulator 4 is high, the liquid back increases and the lubricity of the compressor increases. descend.
[0100]
However, as shown in FIG. 18, when the oil return pipe 64 is provided together with the oil return hole 5, the oil return flow rate becomes a problem due to the adhesion of sludge. , Oil shortage due to sludge adhesion can be compensated. Further, even when the refrigerant flow rate is small and the liquid level of the accumulator 4 is high, the liquid back from the oil return pipe 64 is small, so that the lubricity of the compressor is not reduced due to excessive liquid back. Thus, by providing the oil return pipe 64 in the accumulator 4, even if sludge adheres to the oil return hole 5, there is no shortage of oil return, and there is no excessive liquid back. A high air conditioner can be obtained.
[0101]
When the orifice 65 of the oil return pipe 64 is provided at one end on the outflow pipe 62 side of the oil return pipe 64 as shown in FIG. 19, the oil return pipe 64 is constituted by a capillary tube 66 as shown in FIG. When both the function of the pipe 64 and the function of the orifice 65 are provided, as shown in FIG. 21, the outflow pipe 62 is inserted from above the container 60, the oil return pipe 64 is provided outside the container 60, and the oil return hole When the oil return pipe and the orifice 67 are provided in place of 5, the same effect as that of the seventeenth embodiment is obtained even when the outflow pipe 62 is U-shaped as shown in FIG.
[0102]
Embodiment 18 FIG.
The eighteenth embodiment of the present invention will be described below with reference to FIGS. 23, 24 and 25. FIG. FIG. 23 is a block diagram showing the refrigerant circuit and control circuit of the air-conditioning apparatus according to the eighteenth embodiment, FIG. 24 is a block diagram showing the throttle device control apparatus according to the twenty-second embodiment, and FIG. It is a flowchart explaining an apparatus control operation. In the figure, A is a heat source unit, B, C and D are indoor units, 1 is a compressor, 2 is a switching valve, 3 is a heat source side heat exchanger, 4 is an accumulator, 5 is an oil return hole, 7b, 7c and 7d are indoor unit side heat exchangers, 8b, 8c and 8d are first expansion devices, 9 is a liquid side connection refrigerant pipe, 10 is a gas side connection refrigerant pipe, and the above is the same as the conventional example shown in FIG. belongs to.
[0103]
31 is a discharge pressure detecting means provided between the discharge portion of the compressor 1 and the switching valve 2, and 32 is a third pressure provided between the heat source machine side heat exchanger 3 and the liquid side connection refrigerant pipe 9. The temperature detecting means 33b, 33c, 33d are the fourth expansion units provided between the first expansion devices 8b, 8c, 8d in the indoor units B, C, D and the indoor heat exchangers 7b, 7c, 7d. The temperature detection means 34b, 34c, 34d are fifth temperature detection means 35 provided at one end of the indoor side heat exchangers 7b, 7c, 7d in the indoor units B, C, D on the gas side connection refrigerant pipe 10 side, 35 Is a throttling device control device, 36 is a detection value of the third temperature detection means 32 from the detection value of the third temperature detection means 32, the detection value of the first pressure detection means 31, and the calculation result of the composition calculation means 22 of the mixed refrigerant. SC calculation means 37 for calculating the degree of supercooling of the installation part, 37 is the fourth temperature detection means 33b SH calculating means for calculating the degree of superheat at the outlet portion of the indoor heat exchanger from the detected values of 33c and 33d and the detected values of the fifth temperature detecting means 34b, 34c and 34d; 38, SC calculating means 36; SH calculating means 37 First throttle device control means 39b, 39c, 39d for controlling the opening degree of the first throttle devices 8b, 8c, 8d from the calculation result of the above, blowers provided in the indoor units B, C, D, 40b, 40c and 40d are drain pumps provided in each of the indoor units B, C and D, and 41b, 41c and 41d are defrost control devices.
[0104]
During cooling and heating of the main refrigerant circuit including the compressor 1, the switching valve 2, the heat source device side heat exchanger 3, the first expansion devices 8b, 8c and 8d, and the indoor unit side heat exchangers 7b, 7c and 7d Since the refrigerant flow is exactly the same as in the conventional example, the description thereof will be omitted, and the control operation of the first expansion devices 8b, 8c, and 8d by the expansion device control device will be described with reference to the flowchart of FIG. In step 105, a calculation result SH calculated by the SH calculation means 37 from the detection values of the fourth temperature detection means 33b, 33c, 33d and the detection values of the fifth temperature detection means 34b, 34c, 34d is set in advance. The SH upper limit value SHH is compared, and if SH ≦ SHH, the process proceeds to step 106, and if SH> SHH, the process proceeds to step 108. In step 106, the calculation result SH of the SH calculation means 36 is compared with a preset lower limit value SH of SH, and if SH ≧ SHL, the routine proceeds to step 107, where the first throttling devices 8b, 8c, 8d. If the opening is decreased and SH <SHL, nothing is done. In step 108, the opening degree Sj of the first expansion devices 8b, c, d is compared with the preset upper limit opening degree MAX,
If Sj ≦ MAX, the routine proceeds to step 109 where the opening degree of the first expansion devices 8b, 8c, 8d is increased, and if Sj> MAX, the routine proceeds to step 110.
[0105]
In step 110, the calculation result calculated by the SC calculation means 36 from the detection value of the third temperature detection means 32, the detection value of the first pressure detection means 31, and the calculation result of the composition calculation means 22 of the mixed refrigerant; The SC lower limit value SCL set in advance is compared. If SC> SCL, the routine proceeds to step 111 where the upper limit opening MAX is set to a larger value, and if SC ≦ SCL, nothing is done. As described above, when the first expansion devices 8b, 8c, and 8d are insufficient in flow rate due to sludge adhesion, the supercooling is sufficiently ensured in a certain portion of the third temperature detecting means 32, and the control is diverged. If not, the shortage of flow is eliminated because the maximum opening is set large.
[0106]
Embodiment 19. FIG.
A nineteenth embodiment of the present invention will be described below with reference to FIGS. 23, 26 and 27. FIG. FIG. 26 is a block diagram showing a defrosting control apparatus according to the nineteenth embodiment, and FIG. 27 is a flowchart for explaining the defrosting control operation. In FIG. 26, 34b, 34c, 34d are fifth temperature detecting means 39b provided at one end of the indoor side heat exchangers 7b, 7c, 7d in the indoor units B, C, D on the gas side connection refrigerant pipe 10 side. 39c, 39d are blowers provided in the indoor units B, C, D, 40b, 40c, 40d are drain pumps provided in the indoor units B, C, D, and 41b, 41c, 41d are defrost control devices. , 42 is a system mode determination means for determining whether or not the system mode is cooling, and 43b, 43c and 43d are indoor units for determining whether or not the mode of each of the indoor units B, C and D is cooling. Mode determining means, 44b, 44c, 44d are time measuring means for each of the indoor units B, C, D, 45 is an indoor unit that controls the operation for defrosting the heat exchanger of the indoor unit that is not cooled. It is a frost operation control means.
[0107]
When some of the indoor units, for example, B are in cooling operation, the room temperature and the outside air temperature are low, and the remaining indoor units C and D are stopped, the first throttle device 8d of the stopped indoor units C and D is There is a case where a minute flow rate of refrigerant flows without being completely closed by the attached sludge. In this case, since there is no heat for gasifying the minute flow rate refrigerant and the room temperature and the outside air temperature are low, the indoor side heat exchangers 7d of the stopped indoor units C and D are frosted. When falling into such a state, the temperature of the fifth temperature detecting means 34c, 34d of the indoor units C, D becomes low. Detection values T of the fifth temperature detection means 34c, 34d of such indoor units C, D _Five Is a preset first predetermined temperature T _L The lower state is the first predetermined time τ _1B Subsequently, this is detected by the fifth temperature detection means 34c, 34d, the system mode determination means 42, the indoor unit mode determination means 43c, 43d, and the time measuring means 44c, 44d, and the indoor unit defrosting operation control means 45 is detected. Thus, the blowers 39c and 39d are operated to defrost the indoor heat exchangers C and D, and at the same time, the drain pumps 40c and 40d are also operated, and the drain water generated at this time is controlled to be drained.
[0108]
In addition, a second predetermined time τ after the start of the operation of the blowers 39c and 39d _2B After the elapse of time, the detected values T of the fifth temperature detecting means 34c, 34d of the indoor units C, D _Five Is T _L Second predetermined temperature T set in advance higher _H If it is higher, the fans 39c and 39d are stopped, and the drain water continues to be generated for a while after the fans 39c and 39d are stopped. Therefore, the third predetermined time τ after the fans 39c and 39d are stopped. _3B The drain pumps 40c and 40d are controlled to stop after the passage. As described above, the frost on the indoor side heat exchanger of the stopped indoor unit continues to grow even when the closed state cannot be completely closed by the sludge attached to the first throttle device of the stopped indoor unit. There is no problem.
[0109]
Next, the control operation of the indoor unit defrosting operation control means 45 will be described with reference to the flowchart of FIG. As a result of the determination by the system mode determination means 42, the system mode is cooling, and as a result of the determination by the indoor unit mode determination means 43b, 43c, 43d, the indoor unit mode is not cooling, and the timing means 44b , 44c, 44d, the first time τ ₁ Is the first predetermined time τ _1B Elapsed and the detection value T of the fifth temperature detection means 34b, 34c, 34d _Five Is the first predetermined temperature T _L If it is below, the process proceeds from step 112 to steps 116 through steps 113, 114, and 115, and the second timing τ by the timing means 44b, 44c, and 44d. ₂ Is cleared to 0 and the routine proceeds to step 117, where the fans 39b, 39c, 39d and the drain pumps 40b, 40c, 40d are started to operate.
[0110]
Then, the process proceeds to step 118 and the second time τ ₂ Is the second predetermined time τ _2B The process proceeds to step 119, where the detected value T of the fifth temperature detecting means 34b, 34c, 34d is detected. _Five Is the second predetermined temperature T _H This determination is continued until these conditions are satisfied. When the conditions are satisfied, the routine proceeds to step 120, where the operation of the fans 39b, 39c, 39d is stopped, and in step 121, the timing means 44b, 44c. , 44d third time τ _Three Is cleared to 0 and the routine proceeds to step 122 where the third time τ _Three Is the third predetermined time τ _3B After the elapse, the process proceeds to step 123, and the operation of the drain pumps 40b, 40c, 40d is stopped.
[0111]
【The invention's effect】
[0117]
Invention of the present application According to the above, since the oil separator is provided in the compressor discharge section, and the oil return bypass circuit is provided to return the separated refrigeration oil to the compressor suction section, the flow rate of the refrigeration oil flowing through the throttle device of the main refrigerant circuit is significantly reduced. In addition, the integrated flow rate of the deteriorated refrigeration oil circulating with the refrigeration oil also decreases. As a result, the amount of the refrigeration oil deteriorated matter that becomes sludge and adheres to the expansion device of the main refrigerant circuit is also reduced. As described above, the shortage of the flow rate of the expansion device of the main refrigerant circuit can be avoided, and the lack of air conditioning capability is eliminated. Further, it is possible to avoid an abnormal increase in high pressure, a decrease in low pressure, and an increase in discharge gas temperature, thereby significantly improving the reliability.
[0118]
Of this application According to the invention, Above In the present invention, a sludge filter is provided in the middle of the oil return bypass circuit. Above In addition to the effects of the present invention, the refrigeration oil degradation product generated inside the compressor is captured by the sludge filter in the oil return bypass, and the content of the refrigeration oil degradation product in the refrigeration oil is reduced. The amount of sludge adhering to the throttle device and the oil return hole is reduced, and the refrigerant discharged from the compressor returns to the compressor through the oil return bypass, and the liquid side connection refrigerant pipe and the gas side connection refrigerant are in the middle of the cycle. Since it does not go through the piping, the oxidation scale that occurs when sufficient non-oxidizing brazing is not performed during construction of the liquid-side refrigerant piping and gas-side refrigerant piping should flow into the sludge filter during operation. There is an effect that there is no danger of blocking the flow path or deforming or destroying the sludge filter.
[0119]
Other inventions of this application According to Above In the present invention, since a bypass heat exchanger for cooling the refrigeration oil is provided upstream of the sludge filter in the middle of the oil return bypass circuit, Above In addition to the effect of the present invention, the temperature of the refrigerating machine oil flowing into the sludge filter is lowered and the concentration of the refrigerant in the refrigerating machine oil is increased, so that the deteriorated refrigerating machine oil that has been dissolved in the refrigerating machine oil is deposited and originally frozen. What has been dissolved in the machine oil is also captured by the sludge filter, and there is an effect that the content of the deteriorated refrigeration oil in the refrigeration oil in the main refrigerant circuit is further reduced.
[0120]
Other inventions of this application According to Above In the present invention, since a liquid refrigerant injection circuit for injecting liquid refrigerant upstream of the sludge filter in the middle of the oil return bypass circuit is provided, Above In addition to the effect of the invention, the refrigerant concentration in the refrigerating machine oil flowing into the sludge filter is increased by the refrigerating machine oil in the oil return bypass circuit joining with the liquid refrigerant flowing out of the liquid injection circuit, and is dissolved in the refrigerating machine oil. The refrigeration oil deterioration product that has been deposited and originally dissolved in the refrigeration oil is also captured by the sludge filter, and the content of the refrigeration oil deterioration product in the refrigeration oil in the main refrigerant circuit is further reduced.
[0121]
Other inventions of this application According to Above In the invention, since the sludge filter in the middle of the oil return bypass is a dryer that absorbs moisture and has a sludge filter function, Above In addition to the effects of the invention, by directly absorbing moisture from the refrigeration oil flowing through the oil return bypass, the hydrolysis of the refrigeration oil is suppressed, and the content of the refrigeration oil degradation product in the refrigeration oil in the main refrigerant circuit is further reduced. There is an effect of doing.
[0123]
Other inventions of this application According to Above In the present invention, because it is configured to pass through the lowermost part of the heat source unit side heat exchanger as all or part of the bypass heat exchanger, Above In addition to the effect of the present invention, there is an effect that it is difficult for the wind to pass through by the drain flow at the upper part, and the lowermost part of the heat exchanger that is likely to be frosted is warmed and is less likely to be frosted.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 2.
FIG. 3 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 3.
FIG. 4 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 4.
FIG. 5 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 5.
6 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 6. FIG.
FIG. 7 is a block diagram relating to composition calculation of an air conditioner according to a seventh embodiment;
FIG. 8 is a flowchart showing the operation of the composition calculating means of the air conditioner according to the seventh embodiment.
FIG. 9 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 8.
FIG. 10 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 9.
FIG. 11 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 10.
12 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 11. FIG.
FIG. 13 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 12.
FIG. 14 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 13.
FIG. 15 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 14.
FIG. 16 is a refrigerant circuit diagram of the air-conditioning apparatus according to Embodiment 15.
FIG. 17 is a longitudinal sectional view showing a sixteenth embodiment of a dryer used in the first to sixth embodiments.
FIG. 18 is a longitudinal sectional view showing an axial state 17 according to a seventeenth embodiment used in each embodiment.
FIG. 19 is a longitudinal sectional view showing an eighteenth embodiment of an accumulator.
FIG. 20 is a longitudinal sectional view showing an embodiment 19 of an accumulator.
FIG. 21 is a longitudinal sectional view showing an embodiment 20 of an accumulator.
FIG. 22 is a longitudinal sectional view showing an embodiment 21 of an accumulator.
FIG. 23 is a configuration diagram showing a refrigerant circuit and a control circuit of an air-conditioning apparatus according to Embodiments 22 and 23.
FIG. 24 is a block diagram showing a diaphragm control device according to a twenty-second embodiment;
FIG. 25 is a flowchart for explaining a diaphragm device control operation according to the twenty-second embodiment;
FIG. 26 is a block diagram showing a defrosting control apparatus according to a twenty-third embodiment;
FIG. 27 is a flowchart for explaining a defrosting control operation according to a twenty-third embodiment;
FIG. 28 is a refrigerant circuit diagram of a conventional air conditioner.
[Explanation of symbols]
A heat source machine, B, C, D indoor unit, 1 compressor, 2 switching valve, 3 heat source machine side heat exchanger, 4 accumulator, 5 oil return hole of accumulator, 6 second throttling device ( 7b, 7c, 7d indoor unit side heat exchangers, 8b, 8c, 8d first expansion device (cooling time expansion device), 9 liquid side connection refrigerant pipe, 10 gas side connection refrigerant pipe, 15 Bypass circuit, 16 dryer, 17 Third expansion device (bypass expansion device), 18, 27 Bypass heat exchanger, 18a First bypass heat exchanger, 18b Second bypass heat exchanger, 19 First temperature detection Means, 20 second temperature detecting means, 21 suction pressure detecting means, 22 composition calculating means, 23 oil separator, 24 oil return bypass circuit, 25 fourth throttling device, 26 sludge filter, 28 liquid refrigerant injection circuit, 29 Liquid injection circuit heat exchanger , 30 fifth throttling device, 31 discharge pressure detecting means, 32 third temperature detecting means, 33b, 33c, 33d fourth temperature detecting means, 34b, 34c, 34d fifth temperature detecting means, 35 throttling device control Device, 36 SC calculation means, 37 SH calculation means, 38 throttling device control means, 39b, 39c, 39d defrost blower, 40b, 40c, 40d drain pump, 41b, 41c, 41d defrost control device, 62 accumulator Outflow piping, 64 oil return piping.

Claims (5)

圧縮機、凝縮器、絞り装置、蒸発器より構成された主冷媒回路を備え、ハイドロフルオロカ−ボン系の冷媒を作動媒体として用い、この冷媒と相溶性のある油を冷凍機油として用いる空気調和装置において、
上記圧縮機吐出部に油分離器を設け、分離した冷凍機油を圧縮機吸入部に戻す返油バイパス回路と、上記返油バイパス回路途中に上記冷凍機油が劣化して生成される冷凍機油劣化物を補足するスラッジフィルタを設けたことを特徴とする空気調和装置。An air conditioner that includes a main refrigerant circuit composed of a compressor, a condenser, a throttle device, and an evaporator, uses a hydrofluorocarbon refrigerant as a working medium, and uses oil compatible with the refrigerant as a refrigerator oil. In the device
An oil separator is provided at the compressor discharge section, and a return oil bypass circuit for returning the separated refrigerating machine oil to the compressor suction section, and a refrigerating machine oil deterioration product generated by the deterioration of the refrigerating machine oil in the middle of the return oil bypass circuit An air conditioner provided with a sludge filter for supplementing. 返油バイパス回路途中のスラッジフィルタ上流に冷凍機油を冷却するバイパス熱交換器を設けたことを特徴とする請求項１記載の空気調和装置。 The air conditioner according to claim 1, wherein a bypass heat exchanger for cooling the refrigeration oil is provided upstream of the sludge filter in the middle of the oil return bypass circuit. 返油バイパス回路途中のスラッジフィルタ上流に液冷媒を注入する液冷媒注入回路を設けたことを特徴とする請求項１記載の空気調和装置。 The air conditioner according to claim 1, further comprising a liquid refrigerant injection circuit for injecting liquid refrigerant upstream of the sludge filter in the middle of the oil return bypass circuit. 返油バイパス回路途中のスラッジフィルタを、水分を吸収しかつスラッジフィルタ機能を有するドライヤとしたことを特徴とする請求項１〜３の何れかに記載の空気調和装置。 The air conditioner according to any one of claims 1 to 3, wherein the sludge filter in the middle of the oil return bypass circuit is a dryer that absorbs moisture and has a sludge filter function. バイパス熱交換器の全部または一部として熱源機側熱交換器の最下部を通す構成としたことを特徴とする請求項２に記載の空気調和装置。 The air conditioner according to claim 2, wherein the lowermost part of the heat source unit side heat exchanger is passed as all or part of the bypass heat exchanger.

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