JP4280561B2

JP4280561B2 - Air conditioner

Info

Publication number: JP4280561B2
Application number: JP2003165980A
Authority: JP
Inventors: 明寺崎; 岳志渡部
Original assignee: Sanyo Electric Co Ltd; Toshiba Carrier Corp
Current assignee: Sanyo Electric Co Ltd; Toshiba Carrier Corp
Priority date: 2003-06-11
Filing date: 2003-06-11
Publication date: 2009-06-17
Anticipated expiration: 2023-06-11
Also published as: JP2005003251A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば、冷房運転、氷蓄熱運転、氷蓄熱利用冷房運転、暖房運転及び温蓄運転等を可能にした空気調和装置に関する。
【０００２】
【従来の技術】
一般に、圧縮機、四方弁、室外熱交換器、室外側膨張弁、蓄熱コイル、室内側膨張弁並びに室内熱交換器を冷媒配管で接続し、前記圧縮機の駆動により、冷房運転、氷蓄熱運転、氷蓄熱利用冷房運転、及び暖房運転等を可能にした空気調和装置が知られている（例えば、特許文献１参照）。
【０００３】
この種のものでは、例えば、電気料金が安価な深夜に、氷蓄熱運転を行い、この蓄熱エネルギを利用して、昼間に氷蓄熱利用冷房運転を行い、昼間の冷房効率を向上させている。ところで、従来の構成では、冷房運転を行う場合、室外側膨張弁を開いた状態で、室内側膨張弁の弁開度を絞る制御を行い、これとは反対に、暖房運転を行う場合、室内側膨張弁を開いた状態で、室外側膨張弁の弁開度を絞る制御が実行される。また、氷蓄熱運転を行う場合には、室内膨張弁を閉じ、室外膨張弁を開放し、蓄熱用の膨張弁の開度制御により冷媒の絞り制御が行われる。この氷蓄熱運転によって生成された氷を利用した氷蓄熱利用冷房運転を行う場合には、室内膨張弁で主に冷媒の絞り制御が行われ、その他の膨張弁で冷媒の流量調整が行われる。除霜運転時の熱源の一部として温水が利用されるが、この温水を蓄熱槽に生成する温蓄運転時には、室内膨張弁を閉じ、蓄熱用の膨張弁を開放し、室外膨張弁の開度制御によって冷媒の絞り制御が行われる。これら膨張弁の開閉制御の関係は、図１５に示す通りであるが、いずれの制御であっても、液管内には余剰の液冷媒が滞留し、これを貯留するため、従来、室内外の膨張弁間の液管に受液器が接続されている。
【０００４】
【特許文献１】
特開２００２−３７２３２５号公報
【０００５】
【発明が解決しようとする課題】
しかし、従来の構成では、図１５に示すように、各運転時に各種の膨張弁の弁開度を個別に制御することになり、この場合、室内側膨張弁と室外側膨張弁の２つの膨張弁が必ず必要になる。そうなると、製造コストが嵩むと共に、膨張弁接続のための配管接続やその制御が面倒になる等の問題がある。
【０００６】
そこで、本発明の目的は、上述した従来の技術が有する課題を解消し、いわゆる膨張弁の数を減らし、その制御を簡素化し、かつシンプルな構成の空気調和装置を提供することにある。
【０００７】
【課題を解決するための手段】
請求項１記載の発明は、圧縮機、四方弁、室外熱交換器、蓄熱槽に水没状態で配置される蓄熱コイル、室内側膨張弁並びに室内熱交換器を冷媒配管で接続し、前記圧縮機の駆動により、冷房運転、蓄熱槽に氷を生成させる氷蓄熱運転、及び生成した氷を利用した氷蓄熱利用冷房運転を可能にした空気調和装置において、前記室外熱交換器と前記室内熱交換器との間に、少なくとも４つの逆止弁、及びこれら逆止弁の内、２つの逆止弁の組みを連通させるメイン管路を有したブリッジ回路を接続し、このブリッジ回路のメイン管路に受液器とメイン膨張弁とを直列に接続し、冷房運転、氷蓄熱運転、及び氷蓄熱利用冷房運転のいずれの運転中にも、前記メイン管路に接続された受液器、メイン膨張弁の順に冷媒が流れるようにし、前記蓄熱コイルの一端を、解氷弁を介して受液器とメイン膨張弁間のメイン管路に接続し、前記蓄熱コイルの他端を、蓄熱弁を介してブリッジ回路と室内側膨張弁間に接続したことを特徴とする。
【０００８】
請求項２記載の発明は、請求項１記載のものにおいて、圧縮機、四方弁、室外熱交換器を室外ユニットに収容し、蓄熱コイル、ブリッジ回路、室内側膨張弁を蓄熱ユニットに収容し、室内熱交換器を室内ユニットに収容し、各ユニット間を冷媒配管で接続したことを特徴とする。
【０００９】
請求項３記載の発明は、請求項１又は２記載のものにおいて、前記ブリッジ回路の前記受液器の上部から均圧管を導出し、この均圧管を前記メイン膨張弁の下流に接続したことを特徴とする。
【００１１】
請求項４記載の発明は、請求項１乃至３のいずれか一項記載のものにおいて、空気熱源による暖房運転、四方弁の切り換えによって蓄熱槽に温水を生成させる温蓄運転、この温水を利用した除霜運転を可能にしたことを特徴とする。
【００１２】
【発明の実施の形態】
以下、本発明の一実施形態を添付した図面を参照して説明する。
【００１３】
図１において、１００は本実施形態に係る空気調和装置を示し、この空気調和装置１００は、室外ユニット１０と、蓄熱ユニット２０と、室内ユニット３０の３つのユニットを備えて構成されている。室外ユニット１０は、圧縮機１と、四方弁２と、室外熱交換器３と、アキュームレータ４とを備えて構成される。蓄熱ユニット２０は、室外ユニット１０に接続されるブリッジ回路４０を含んで構成される。このブリッジ回路４０は、第１逆止弁４１、第２逆止弁４２、第３逆止弁４３、第４逆止弁４４、並びにこれら逆止弁の内、２つの逆止弁の組み（逆止弁４１と４３、及び逆止弁４２と４４）を連通させるメイン管路４５を含み、このメイン管路４５には、受液器４６及びメイン膨張弁４７が直列に接続されている。また、受液器４６の上部からバイパス管路（均圧管）４８が導出され、このバイパス管路４８には均圧弁４９が接続され、この均圧弁４９はメイン膨張弁４７の下流のメイン管路４５に接続されている。
【００１４】
蓄熱ユニット２０には、蓄熱槽５０が含まれる。この蓄熱槽５０の中には、蓄熱コイル５１が水没状態で配置され、この蓄熱コイル５１の一端は、第１管路５２、二方弁５４を介してガス管６０に接続されている。蓄熱コイル５１の他端は、第２管路５３、蓄熱弁５５を介して液管６１、すなわちブリッジ回路４０と室内側膨張弁２１との間の液管６１に接続されている。
【００１５】
ブリッジ回路４０のメイン管路４５であって、受液器４６とメイン膨張弁４７の間のメイン管路４５には、第３管路６３が接続され、この第３管路６３は、解氷弁５６、逆止弁５７を介して第１管路５２、すなわち二方弁５４と蓄熱コイル５１との間の第１管路５２に接続されている。
【００１６】
上述のブリッジ回路４０には、液管６１を介して、室内側膨張弁２１が接続され、この室内側膨張弁２１には室内ユニット３０の室内熱交換器３１が接続され、この室内熱交換器３１にはガス管６０を介して四方弁２が接続されている。なお、室内側膨張弁２１は蓄熱ユニット２０に含まれる。
【００１７】
次に、本実施形態の動作を説明する。
【００１８】
図１では、一般的な冷房運転（氷蓄熱未利用冷房運転）時の冷媒の流れを太線で示す。圧縮機１で圧縮された冷媒は、四方弁２を介して室外熱交換器３に流入し、ここで凝縮する。この凝縮した冷媒はブリッジ回路４０に入る。このブリッジ回路４０では、第１逆止弁４１を経てメイン管路４５に入り、メイン管路４５に接続された受液器４６を介してメイン膨張弁４７に入る。
【００１９】
そして、メイン膨張弁４７を経た後、第３逆止弁４３を介して液管６１に向かい、ここから、室内側膨張弁２１を経て、室内ユニット３０の室内熱交換器３１に流入する。この室内熱交換器３１では、冷媒が蒸発して、周囲から蒸発潜熱を奪い、室内を冷房する。そして、室内熱交換器３１を経た冷媒は、ガス管６０を通り、四方弁２、アキュームレータ４を経て圧縮機１の吸込管に戻される。
【００２０】
本実施形態では、夜間の安価な電気を使用して氷蓄熱運転が行われる。この氷蓄熱運転では、図２に太線で示すように冷媒が流される。すなわち、圧縮機１で圧縮された冷媒は、四方弁２、室外熱交換器３を通り、ブリッジ回路４０に流入し、このブリッジ回路４０の第１逆止弁４１を経てメイン管路４５に流入する。メイン管路４５に流入した冷媒は、受液器４６、メイン膨張弁４７を経て第３逆止弁４３に至り、ここから液管６１に流入する。この液管６１に流入した冷媒は、蓄熱弁５５、第２管路５３を通り蓄熱コイル５１に流入し、ここで蒸発し蓄熱槽５０内に製氷する。
【００２１】
蓄熱槽５０内に製氷させた冷媒は、第１管路５２、二方弁５４を通りガス管６０に流入し、更に、四方弁２、アキュームレータ４を経て圧縮機１に戻される。
【００２２】
冷房運転には、図１に示す氷蓄熱未利用冷房運転の他に、図２に示す製氷を利用した、氷蓄熱利用冷房運転が含まれる。
【００２３】
この利用冷房運転では、図３に示すように、冷媒制御が行われる。すなわち、圧縮機１で圧縮された冷媒は四方弁２、室外熱交換器３を経て、ブリッジ回路４０に流入し、このブリッジ回路４０の第１逆止弁４１、メイン管路４５、受液器４６を経て、一方は第３管路６３に流入し、他方はそのままメイン管路４５を流れてメイン膨張弁４７に至る。
【００２４】
第３管路６３に流入した冷媒は、解氷弁５６、逆止弁５７を経て蓄熱槽５０内の蓄熱コイル５１に入る。この冷媒は、蓄熱コイル５１内で氷により過冷却され、その後に、第２管路５３を経て蓄熱弁５５を通り液管６１に流入する。また、ブリッジ回路４０の受液器４６を経て、そのままメイン膨張弁４７に流入した冷媒は、第３逆止弁４３を通り液管６１に流入する。
【００２５】
この液管６１では、蓄熱コイル５１を経て過冷却された冷媒と、メイン膨張弁４７を経た冷媒とが合流し、この合流した冷媒は、室内側膨張弁２１を通り、室内ユニット３０の室内熱交換器３１に流入する。この室内熱交換器３１では、冷媒が蒸発し、これにより室内が冷房される。そして、室内熱交換器３１を経た冷媒は、ガス管６０を通り、四方弁２、アキュームレータ４を経て、圧縮機１の吸込管に戻される。
【００２６】
この場合、本実施形態では、冷媒が蓄熱槽５０で過冷却された分だけ、冷房効率を向上させることができる。
【００２７】
上記構成では暖房運転が可能である。この暖房運転では、図４に示すように、冷媒の流れが制御される。
【００２８】
すなわち、圧縮機１に吐出された冷媒は、四方弁２を通りガス管６０に流入し、このガス管６０を経て室内ユニット３０の室内熱交換器３１に流入し、この室内熱交換器３１で凝縮し、これにより、室内が暖房される。この室内熱交換器３１を経た冷媒は、室内側膨張弁２１を通り、液管６１に流入し、更にブリッジ回路４０に流入する。このブリッジ回路４０に入ると、冷媒は、第２逆止弁４２を経てメイン管路４５に流入し、受液器４６、メイン膨張弁４７を経て第４逆止弁４４に至り、この第４逆止弁４４を通過して、室外ユニット１０の室外熱交換器３に流入する。この室外熱交換器３では、冷媒が蒸発し、これによりガス化された冷媒が、四方弁２、アキュームレータ４を経て圧縮機１に戻される。
【００２９】
この暖房運転が、厳冬期等の著しい低外気温の状態下で行われた場合、室外熱交換器３のフィンに着霜する。この室外熱交換器３の着霜を除去するため、除霜運転が行われる。
【００３０】
図５は、空気除霜運転を示す。この除霜運転では、暖房運転を一時的に停止し、四方弁２を冷房位置に切り換え、圧縮機１を駆動する。すると、図５に示すように、圧縮機１で圧縮された冷媒が、四方弁２を経て、室外熱交換器３に直接流入し、ここに直接流入したホットガスにより室外熱交換器３が除霜される。この室外熱交換器３を経た冷媒は、図１に示す冷房運転の場合とほぼ同様の流れを経て圧縮機１に戻される。
【００３１】
図６は、蓄熱槽に温水を生成する温蓄運転を示す。この温蓄運転では、蓄熱槽５０内の水の温度を上昇させる。この温蓄運転では、圧縮機１で圧縮された冷媒が、四方弁２を通り、ガス管６０に流入し、このガス管６０から二方弁５４、第１管路５２を経て、蓄熱コイル５１に流入する。冷媒は、この蓄熱コイル５１で凝縮し、蓄熱槽５０内の水温を上昇させる。この蓄熱コイル５１を経た冷媒は、第２管路５３、蓄熱弁５５を通りブリッジ回路４０に流入し、このブリッジ回路４０に流入した冷媒は、第２逆止弁４２を通りメイン管路４５に入り、受液器４６、メイン膨張弁４７を経て第４逆止弁４４に至る。
【００３２】
そして、第４逆止弁４４を経て室外ユニット１０の室外熱交換器３に至り、ここで蒸発し、ガス化した冷媒が、四方弁２、アキュームレータ４を経て圧縮機１に戻される。
【００３３】
この温蓄運転によって、蓄熱槽５０内に温蓄されたエネルギは、図７に示すように、専ら温水除霜運転に利用される。
【００３４】
すなわち、圧縮機１で圧縮された冷媒は、四方弁２を経て、室外熱交換器３に流入し、この室外熱交換器３で凝縮し、この室外熱交換器３のフィンに付着した霜を除去する。室外熱交換器３を経た冷媒は、ブリッジ回路４０に入り、このブリッジ回路４０の第１逆止弁４１、メイン管路４５、受液器４６、メイン膨張弁４７を経て第３逆止弁４３に至り、ここから蓄熱弁５５、第２管路５３を通り、蓄熱コイル５１に流入する。
【００３５】
この蓄熱コイル５１では、冷媒が、蓄熱槽５０内の温蓄エネルギから熱を奪い、いわゆる冷媒加熱されて第１管路５２を経て二方弁５４に至る。そして、二方弁５４からガス管６０に入り、四方弁２、アキュームレータ４を経て圧縮機１に戻される。
【００３６】
この温水利用による除霜運転では、蓄熱槽５０内で冷媒が加熱されて圧縮機１に戻されるため、除霜運転の効率が向上し、除霜運転を、図５の除霜運転に比べて短時間のうちに終了させることができる。
【００３７】
本実施形態では、図１〜図７に示すように、いかなる運転モードにおいてもブリッジ回路４０のメイン管路４５を通る冷媒は、まず、受液器４６に入り、それを経てからメイン膨張弁４７に至る。従って、冷房運転時、或いは暖房運転時において、弁開度を制御すべき膨張弁は、主にこの一つのメイン膨張弁４７だけである。なお、氷蓄熱利用冷房運転時には、メイン膨張弁４７において、冷媒流量の補助調整が行われる。蓄熱槽５０を有した空気調和装置１００では、その冷凍サイクル内への冷媒充填量は多い。従って、いずれの運転時であっても、メイン膨張弁４７の弁開度を絞ることにより、液管６１内には余剰の液冷媒が滞留する。この余剰の冷媒は、メイン膨張弁４７の上流に位置する受液器４６に貯留される。
【００３８】
上記構成では、従来のように、冷房運転を行う場合、室外側膨張弁を開いた状態で、室内側膨張弁の弁開度を絞る制御を行い、これとは反対に、暖房運転を行う場合、室内側膨張弁を開いた状態で、室外側膨張弁の弁開度を絞る制御、等が不要になり、その結果、従来の構成では、少なくとも２個必要であった膨張弁を、１つのメイン膨張弁４７で構成することが可能になり、膨張弁の個数を削減でき、コストダウンが図られる。なお、氷蓄熱利用冷房運転時は、２つの膨張弁によって減圧、並びに流量調整が行われる。
【００３９】
上記構成では、ブリッジ回路４０の受液器４６の上部から均圧管４８が導出され、この均圧管４８がメイン膨張弁４７の下流に接続される。一般に、空気調和装置１００の運転停止時に、このメイン膨張弁４７を境に、その前後に低圧のガス冷媒領域と高圧の液冷媒領域とが形成される。従来、膨張弁を開放して各領域を均圧したが、これだと、圧縮機１の再起動時に、大量の液冷媒が低圧ガス冷媒領域に流入して、圧縮機１への液バックを起こす。従来、アキュームレータ４の容量は大容量（例えば、７．５リットル）としている。
【００４０】
圧縮機１への液バックを解消するため、上記構成では、空気調和装置１００の運転停止時に、メイン膨張弁４７が閉じられ、均圧管４８の均圧弁４９が開放される。これにより均圧管４８を経て、メイン膨張弁４７の前後の管が連通し、当該メイン膨張弁４７の前後の圧力が均圧される。
【００４１】
この場合、受液器４６の上部にはガス冷媒が滞留するため、均圧管４８の均圧弁４９が開放されたとしても、均圧管４８を経て移動するのはガス冷媒であり、液冷媒の移動はない。この場合、アキュームレータ４の容量は小容量（例えば、２．５リットル）とすることができ、このアキュームレータ４の容量は、いわゆる汎用室外ユニットのものと同じである。
【００４２】
上記構成では、メイン膨張弁４７をブリッジ回路４０に組み込み、このブリッジ回路４０を蓄熱ユニット２０に収容すると共に、この蓄熱ユニット２０には、室内膨張弁２１を収容したため、室外ユニット１０、並びに室内ユニット３０には、膨張弁を収容する必要がない。また、室外ユニット１０内のアキュームレータ４の容量は、上述したように、汎用ユニット同様に小容量（例えば、２．５リットル）である。従って、空気調和装置１００の室外ユニット１０として、膨張弁を内蔵しない従来の汎用室外ユニットを、空気調和装置１００の蓄熱ユニット２０と組み合わせて使用することが可能になる。
【００４３】
図８〜図１４は別の実施形態を示す。図８〜図１４は、それぞれ図１〜図７に対応した冷媒回路図である。図８において、図１に示す実施形態と異なる点は、蓄熱槽５０周辺における配管系にある。
【００４４】
この蓄熱槽５０の中に水没した蓄熱コイル５１は、その一端が、第１管路５２、二方弁５４を介してガス管６０に接続されると共に、同じく第１管路５２、サブクール弁７１、逆止弁７２を介して液管６１に接続される。蓄熱コイル５１の他端は、第２管路５３、蓄熱弁５５を介して液管６１、すなわちブリッジ回路４０と室内側膨張弁２１との間の液管６１に接続されている。ブリッジ回路４０のメイン管路４５であって、受液器４６とメイン膨張弁４７の間のメイン管路４５には、第３管路６３が接続され、この第３管路６３は、解氷弁５６、逆止弁５７を介して、上述した蓄熱コイル５１の他端に接続されている。その他の構成は、図１に示すものとほぼ同じ構成である。
【００４５】
次に、本実施形態の動作を説明する。
【００４６】
図８では、一般的な冷房運転（氷蓄熱未利用冷房運転）時の冷媒の流れを太線で示す。圧縮機１で圧縮された冷媒は、四方弁２を介して室外熱交換器３に流入し、ここで凝縮する。この凝縮した冷媒はブリッジ回路４０に入る。このブリッジ回路４０では、第１逆止弁４１を経てメイン管路４５に入り、メイン管路４５に接続された受液器４６を介してメイン膨張弁４７に入る。
【００４７】
そして、メイン膨張弁４７を経た後、第３逆止弁４３を介して液管６１に向かい、ここから、室内側膨張弁２１を経て、室内ユニット３０の室内熱交換器３１に流入する。この室内熱交換器３１では、冷媒が蒸発して、周囲から蒸発潜熱を奪い、室内を冷房する。そして、室内熱交換器３１を経た冷媒は、ガス管６０を通り、四方弁２、アキュームレータ４を経て圧縮機１の吸込管に戻される。
【００４８】
本実施形態では、夜間の安価な電気を使用して氷蓄熱運転が行われる。この氷蓄熱運転では、図９に太線で示すように冷媒が流される。すなわち、圧縮機１で圧縮された冷媒は、四方弁２、室外熱交換器３を通り、ブリッジ回路４０に流入し、このブリッジ回路４０の第１逆止弁４１を経てメイン管路４５に流入する。メイン管路４５に流入した冷媒は、受液器４６、メイン膨張弁４７を経て第３逆止弁４３に至り、ここから液管６１に流入する。
【００４９】
この液管６１に流入した冷媒は、蓄熱弁５５、第２管路５３を通り蓄熱コイル５１に流入し、ここで蒸発し蓄熱槽５０内に製氷する。この場合、サブクール弁７１は全閉である。この氷蓄熱運転時における蓄熱コイル５１内の冷媒の流れは、矢印Ｘ方向である。
【００５０】
蓄熱槽５０内に製氷させた冷媒は、第１管路５２、二方弁５４を通りガス管６０に流入し、更に、四方弁２、アキュームレータ４を経て圧縮機１に戻される。
【００５１】
冷房運転には、図８に示す氷蓄熱未利用冷房運転の他に、図９に示す製氷を利用した、氷蓄熱利用冷房運転が含まれる。
【００５２】
この利用冷房運転では、図１０に示すように、冷媒制御が行われる。すなわち、圧縮機１で圧縮された冷媒は四方弁２、室外熱交換器３を経て、ブリッジ回路４０に流入し、このブリッジ回路４０の第１逆止弁４１、メイン管路４５、受液器４６を経て、一方は第３管路６３に流入し、他方はそのままメイン管路４５を流れてメイン膨張弁４７に至る。
【００５３】
第３管路６３に流入した冷媒は、解氷弁５６、逆止弁５７を経て蓄熱槽５０内の蓄熱コイル５１に入る。この氷蓄熱利用冷房運転時における蓄熱コイル５１内の冷媒の流れは、矢印Ｘ方向である。
【００５４】
この冷媒は、蓄熱コイル５１内で氷により過冷却され、その後に、第１管路５２、サブクール弁７１、逆止弁７２を通り液管６１に流入する。また、ブリッジ回路４０の受液器４６を経て、そのままメイン膨張弁４７に流入した冷媒は、第３逆止弁４３を通り液管６１に流入する。
【００５５】
この液管６１では、蓄熱コイル５１を経て過冷却された冷媒と、メイン膨張弁４７を経た冷媒とが合流し、この合流した冷媒は、室内側膨張弁２１を通り、室内ユニット３０の室内熱交換器３１に流入する。この室内熱交換器３１では、冷媒が蒸発し、これにより室内が冷房される。そして、室内熱交換器３１を経た冷媒は、ガス管６０を通り、四方弁２、アキュームレータ４を経て、圧縮機１の吸込管に戻される。この氷蓄熱利用冷房運転時には室内側膨張弁２１で冷媒の膨張作用を行わせ、メイン膨張弁４７で冷媒の流れ調整を行う。
【００５６】
この場合、本実施形態では、冷媒が蓄熱槽５０で過冷却された分だけ、冷房効率を向上させることができる。
【００５７】
上記構成では暖房運転が可能である。この暖房運転では、図１１に示すように、冷媒の流れが制御される。
【００５８】
すなわち、圧縮機１に吐出された冷媒は、四方弁２を通りガス管６０に流入し、このガス管６０を経て室内ユニット３０の室内熱交換器３１に流入し、この室内熱交換器３１で凝縮し、これにより、室内が暖房される。この室内熱交換器３１を経た冷媒は、室内側膨張弁２１を通り、液管６１に流入し、更にブリッジ回路４０に流入する。このブリッジ回路４０に入ると、冷媒は、第２逆止弁４２を経てメイン管路４５に流入し、受液器４６、メイン膨張弁４７を経て第４逆止弁４４に至り、この第４逆止弁４４を通過して、室外ユニット１０の室外熱交換器３に流入する。この室外熱交換器３では、冷媒が蒸発し、これによりガス化された冷媒が、四方弁２、アキュームレータ４、サブアキュームレータ５を経て圧縮機１に戻される。
【００５９】
この暖房運転が、厳冬期等の著しい低外気温の状態下で行われた場合、室外熱交換器３のフィンに着霜する。この室外熱交換器３の着霜を除去するため、除霜運転が行われる。
【００６０】
図１２は、空気除霜運転を示す。この除霜運転では、暖房運転を一時的に停止し、四方弁２を冷房位置に切り換え、圧縮機１を駆動する。すると、図１２に示すように、圧縮機１で圧縮された冷媒が、四方弁２を経て、室外熱交換器３に直接流入し、ここに直接流入したホットガスにより室外熱交換器３が除霜される。この室外熱交換器３を経た冷媒は、図８に示す冷房運転の場合とほぼ同様の流れを経て圧縮機１に戻される。
【００６１】
この場合、室内熱交換器３１の送風ファンの運転は停止し、冷媒を蒸発させない。本来の要求は暖房運転であり、除霜運転時に室内に冷風が吹き出されないようにするためである。
【００６２】
図１３は、温蓄運転を示す。この温蓄運転では、蓄熱槽５０内の水の温度を上昇させる。この温蓄運転では、圧縮機１で圧縮された冷媒が、四方弁２を通り、ガス管６０に流入し、このガス管６０から二方弁５４、第１管路５２を経て、蓄熱コイル５１に流入する。冷媒は、この蓄熱コイル５１で凝縮し、蓄熱槽５０内の水温を上昇させる。この蓄熱コイル５１を経た冷媒は、第２管路５３、蓄熱弁５５を通りブリッジ回路４０に流入し、このブリッジ回路４０に流入した冷媒は、第２逆止弁４２を通りメイン管路４５に入り、受液器４６、メイン膨張弁４７を経て第４逆止弁４４に至る。
【００６３】
そして、第４逆止弁４４を経て室外ユニット１０の室外熱交換器３に至り、ここで蒸発し、ガス化した冷媒が、四方弁２、アキュームレータ４を経て圧縮機１に戻される。
【００６４】
この温蓄運転によって、蓄熱槽５０内に温蓄されたエネルギは、図１４に示すように、専ら温水除霜運転に利用される。
【００６５】
すなわち、圧縮機１で圧縮された冷媒は、四方弁２を経て、室外熱交換器３に流入し、この室外熱交換器３で凝縮し、この室外熱交換器３のフィンに付着した霜を除去する。室外熱交換器３を経た冷媒は、ブリッジ回路４０に入り、このブリッジ回路４０の第１逆止弁４１、メイン管路４５、受液器４６、メイン膨張弁４７を経て第３逆止弁４３に至り、ここから蓄熱弁５５、第２管路５３を通り、蓄熱コイル５１に流入する。
【００６６】
この蓄熱コイル５１では、冷媒が、蓄熱槽５０内の温蓄エネルギから熱を奪い、いわゆる冷媒加熱されて第１管路５２を経て二方弁５４に至る。そして、二方弁５４からガス管６０に入り、四方弁２、アキュームレータ４を経て圧縮機１に戻される。
【００６７】
この温水利用による除霜運転では、蓄熱槽５０内で冷媒が加熱されて圧縮機１に戻されるため、除霜運転の効率が向上し、除霜運転を、図１２の除霜運転に比べて短時間のうちに終了させることができる。
【００６８】
本実施形態では、図８〜図１４に示すように、いかなる運転モードにおいてもブリッジ回路４０のメイン管路４５を通る冷媒は、まず、受液器４６に入り、それを経てからメイン膨張弁４７に至る。従って、冷房運転時、或いは暖房運転時において、弁開度を制御すべき膨張弁はこの一つのメイン膨張弁４７である。いずれの運転時であっても、メイン膨張弁４７の弁開度を絞ることにより、液管６１内には余剰の液冷媒が滞留する。この余剰の冷媒は、メイン膨張弁４７の上流に位置する受液器４６に貯留される。
【００６９】
上記構成では、従来のように、冷房運転を行う場合、室外側膨張弁を開いた状態で、室内側膨張弁の弁開度を絞る制御を行い、これとは反対に、暖房運転を行う場合、室内側膨張弁を開いた状態で、室外側膨張弁の弁開度を絞る制御、等が不要になり、その結果、従来の構成では、少なくとも２個必要であった膨張弁を、１つのメイン膨張弁４７で構成することが可能になり、膨張弁の個数を削減でき、コストダウンが図られる。
【００７０】
上記構成では、ブリッジ回路４０の受液器４６の上部から均圧管４８が導出され、この均圧管４８がメイン膨張弁４７の下流に接続される。一般に、空気調和装置１００の運転停止時に、このメイン膨張弁４７を境に、その前後に低圧のガス冷媒領域と高圧の液冷媒領域とが形成される。従来、膨張弁を開放して各領域を均圧したが、これだと、圧縮機１の再起動時に、大量の液冷媒が低圧ガス冷媒領域に流入して、圧縮機１への液バックを起こす。従来、アキュームレータ４の容量は大容量（例えば、７．５リットル）としている。
【００７１】
圧縮機１への液バックを解消するため、上記構成では、空気調和装置１００の運転停止時に、メイン膨張弁４７が閉じられ、均圧管４８の均圧弁４９が開放される。これにより均圧管４８を経て、メイン膨張弁４７の前後の管が連通し、当該メイン膨張弁４７の前後の圧力が均圧される。
【００７２】
この場合、受液器４６の上部にはガス冷媒が滞留するため、均圧管４８の均圧弁４９が開放されたとしても、均圧管４８を経て移動するのはガス冷媒であり、液冷媒の移動はない。この場合、アキュームレータ４の容量は小容量（例えば、２．５リットル）とすることができ、このアキュームレータ４の容量は、いわゆる汎用室外ユニットのものと同じである。
【００７３】
上記構成では、メイン膨張弁４７をブリッジ回路４０に組み込み、このブリッジ回路４０を蓄熱ユニット２０に収容すると共に、この蓄熱ユニット２０には、室内膨張弁２１を収容したため、室外ユニット１０、並びに室内ユニット３０には、膨張弁を収容する必要がない。また、室外ユニット１０内のアキュームレータ４の容量は、上述したように、汎用ユニット同様に小容量（例えば、２．５リットル）である。従って、空気調和装置１００の室外ユニット１０として、膨張弁を内蔵しない従来の汎用室外ユニットを、空気調和装置１００の蓄熱ユニット２０と組み合わせて使用することが可能になる。
【００７４】
以上、一実施形態に基づいて本発明を説明したが、本発明は、これに限定されるものではない。例えば、空気調和装置１００を、室外ユニット１０、蓄熱ユニット２０、及び室内ユニット３０の３つのユニットで構成したが、これに限定されるものではなく、室外ユニット１０及び蓄熱ユニット２０を一体化させることは可能である。
【００７５】
【発明の効果】
本発明では、膨張弁の数が減らされ、その制御が簡素化され、かつシンプルな構成の空気調和装置が提供される。
【図面の簡単な説明】
【図１】本発明の一実施形態を示す氷蓄熱未利用冷房運転時の冷媒回路図である。
【図２】本発明の一実施形態を示す氷蓄熱運転時の冷媒回路図である。
【図３】本発明の一実施形態を示す氷蓄熱利用冷房運転時の冷媒回路図である。
【図４】本発明の一実施形態を示す暖房運転時の冷媒回路図である。
【図５】本発明の一実施形態を示す空気除霜運転時の冷媒回路図である。
【図６】本発明の一実施形態を示す温蓄運転時の冷媒回路図である。
【図７】本発明の一実施形態を示す温水除霜運転時の冷媒回路図である。
【図８】本発明の他の実施形態を示す氷蓄熱未利用冷房運転時の冷媒回路図である。
【図９】本発明の他の実施形態を示す氷蓄熱運転時の冷媒回路図である。
【図１０】本発明の他の実施形態を示す氷蓄熱利用冷房運転時の冷媒回路図である。
【図１１】本発明の他の実施形態を示す暖房運転時の冷媒回路図である。
【図１２】本発明の他の実施形態を示す空気除霜運転時の冷媒回路図である。
【図１３】本発明の他の実施形態を示す温蓄運転時の冷媒回路図である。
【図１４】本発明の他の実施形態を示す温水除霜運転時の冷媒回路図である。
【図１５】各弁の開閉状態を示す図である。
【符号の説明】
１圧縮機
２四方弁
３室外熱交換器
１０室外ユニット
２０蓄熱ユニット
３０室内ユニット
３１室内熱交換器
２１室内側膨張弁
４０ブリッジ回路
４１〜４４第１〜第４逆止弁
４５メイン管路
４６受液器
４７メイン膨張弁
４８均圧管（バイパス管路）
４９均圧弁
５０蓄熱槽
５１蓄熱コイル
５４二方弁
５５蓄熱弁
５６解氷弁
６０ガス管
６１液管
７１サブクール弁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner that enables, for example, cooling operation, ice heat storage operation, ice heat storage cooling operation, heating operation, and heat storage operation.
[0002]
[Prior art]
Generally, a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion valve, a heat storage coil, an indoor expansion valve and an indoor heat exchanger are connected by a refrigerant pipe, and cooling operation and ice heat storage operation are performed by driving the compressor. In addition, an air conditioner that enables cooling operation using ice heat storage, heating operation, and the like is known (see, for example, Patent Document 1).
[0003]
In this type, for example, ice storage operation is performed in the middle of the night when the electricity rate is low, and this heat storage energy is used to perform cooling operation using ice storage in the daytime to improve daytime cooling efficiency. By the way, in the conventional configuration, when performing the cooling operation, control is performed to reduce the valve opening degree of the indoor expansion valve while the outdoor expansion valve is opened, and on the contrary, when performing the heating operation, In a state where the inner expansion valve is opened, control for reducing the valve opening degree of the outdoor expansion valve is executed. When performing the ice heat storage operation, the indoor expansion valve is closed, the outdoor expansion valve is opened, and the throttle control of the refrigerant is performed by controlling the opening degree of the heat storage expansion valve. When performing an ice heat storage cooling operation using ice generated by the ice heat storage operation, the refrigerant expansion control is mainly performed by the indoor expansion valve, and the refrigerant flow rate is adjusted by the other expansion valves. Hot water is used as part of the heat source during the defrosting operation. During the heat storage operation that generates this hot water in the heat storage tank, the indoor expansion valve is closed, the heat storage expansion valve is opened, and the outdoor expansion valve is opened. The throttle control of the refrigerant is performed by the degree control. The relationship of the expansion valve opening / closing control is as shown in FIG. 15. However, in any control, excessive liquid refrigerant stays in the liquid pipe and is stored. A liquid receiver is connected to the liquid pipe between the expansion valves.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-372325
[Problems to be solved by the invention]
However, in the conventional configuration, as shown in FIG. 15, the valve openings of various expansion valves are individually controlled during each operation, and in this case, two expansions of the indoor expansion valve and the outdoor expansion valve are performed. A valve is absolutely necessary. If it becomes so, while manufacturing cost will increase, there exist problems, such as piping connection for an expansion valve connection, and the control that become troublesome.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems of the prior art, reduce the number of so-called expansion valves, simplify the control, and provide an air conditioner having a simple configuration.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, a compressor, a four-way valve, an outdoor heat exchanger, a heat storage coil disposed in a submerged state in a heat storage tank, an indoor expansion valve, and an indoor heat exchanger are connected by refrigerant piping, and the compressor The outdoor heat exchanger and the indoor heat exchanger in the air conditioner that enabled cooling operation, ice heat storage operation for generating ice in the heat storage tank, and ice storage heat-use cooling operation using the generated ice A bridge circuit having a main line for communicating at least four check valves and a set of two check valves among the check valves, and connected to the main line of the bridge circuit The liquid receiver and the main expansion valve are connected in series, and the liquid receiver and the main expansion valve are connected to the main pipe line during any of the cooling operation, the ice heat storage operation, and the ice heat storage cooling operation. as the refrigerant flows in the order of, the heat storage carp One end of, and connected to the main conduit between the receiver and the main expansion valve via the Kaikoriben, the other end of the thermal storage coil, connected between the bridge circuit and the indoor expansion valve via the heat storage valve It is characterized by that.
[0008]
The invention according to claim 2 is the one according to claim 1, wherein the compressor, the four-way valve, the outdoor heat exchanger are accommodated in the outdoor unit, the heat storage coil, the bridge circuit, and the indoor expansion valve are accommodated in the heat storage unit, The indoor heat exchanger is housed in an indoor unit, and each unit is connected by a refrigerant pipe.
[0009]
According to a third aspect of the present invention, in the first or second aspect of the invention, a pressure equalizing pipe is led out from an upper part of the liquid receiver of the bridge circuit, and the pressure equalizing pipe is connected downstream of the main expansion valve. Features.
[0011]
The invention of claim 4, wherein, in one of any one of claims 1 to 3, the heating operation by the air heat source, Yutaka蓄operation for producing hot water in the thermal storage tank by switching the four-way valve, utilizing this warm water The defrosting operation is made possible.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[0013]
In FIG. 1, reference numeral 100 denotes an air conditioner according to the present embodiment, and the air conditioner 100 includes three units, an outdoor unit 10, a heat storage unit 20, and an indoor unit 30. The outdoor unit 10 includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, and an accumulator 4. The heat storage unit 20 includes a bridge circuit 40 connected to the outdoor unit 10. The bridge circuit 40 includes a first check valve 41, a second check valve 42, a third check valve 43, a fourth check valve 44, and a combination of two check valves among these check valves ( The main valve 45 includes a check valve 41 and 43, and a check valve 42 and 44). A liquid receiver 46 and a main expansion valve 47 are connected to the main pipe 45 in series. A bypass pipe (pressure equalizing pipe) 48 is led out from the upper part of the liquid receiver 46, and a pressure equalizing valve 49 is connected to the bypass pipe 48, and the pressure equalizing valve 49 is a main pipe downstream of the main expansion valve 47. 45.
[0014]
The heat storage unit 20 includes a heat storage tank 50. In the heat storage tank 50, a heat storage coil 51 is disposed in a submerged state, and one end of the heat storage coil 51 is connected to the gas pipe 60 via a first conduit 52 and a two-way valve 54. The other end of the heat storage coil 51 is connected to the liquid pipe 61, that is, the liquid pipe 61 between the bridge circuit 40 and the indoor expansion valve 21 via the second pipe 53 and the heat storage valve 55.
[0015]
A third pipe line 63 is connected to the main pipe line 45 of the bridge circuit 40 between the liquid receiver 46 and the main expansion valve 47, and the third pipe line 63 is connected to the deicing line. The first pipe 52, that is, the first pipe 52 between the two-way valve 54 and the heat storage coil 51 is connected via a valve 56 and a check valve 57.
[0016]
The indoor expansion valve 21 is connected to the bridge circuit 40 via the liquid pipe 61, and the indoor heat exchanger 31 of the indoor unit 30 is connected to the indoor expansion valve 21, and this indoor heat exchanger A four-way valve 2 is connected to 31 via a gas pipe 60. The indoor expansion valve 21 is included in the heat storage unit 20.
[0017]
Next, the operation of this embodiment will be described.
[0018]
In FIG. 1, the flow of the refrigerant at the time of general cooling operation (cooling operation not using ice heat storage) is indicated by a thick line. The refrigerant compressed by the compressor 1 flows into the outdoor heat exchanger 3 through the four-way valve 2 and condenses here. This condensed refrigerant enters the bridge circuit 40. In the bridge circuit 40, the main circuit 45 is entered via the first check valve 41, and the main expansion valve 47 is entered via the liquid receiver 46 connected to the main line 45.
[0019]
Then, after passing through the main expansion valve 47, it goes to the liquid pipe 61 through the third check valve 43, and flows from here through the indoor side expansion valve 21 to the indoor heat exchanger 31 of the indoor unit 30. In the indoor heat exchanger 31, the refrigerant evaporates, takes away latent heat of evaporation from the surroundings, and cools the room. Then, the refrigerant that has passed through the indoor heat exchanger 31 passes through the gas pipe 60 and is returned to the suction pipe of the compressor 1 through the four-way valve 2 and the accumulator 4.
[0020]
In this embodiment, the ice heat storage operation is performed using inexpensive electricity at night. In this ice heat storage operation, the refrigerant flows as shown by a thick line in FIG. That is, the refrigerant compressed by the compressor 1 flows into the bridge circuit 40 through the four-way valve 2 and the outdoor heat exchanger 3, and flows into the main conduit 45 through the first check valve 41 of the bridge circuit 40. To do. The refrigerant flowing into the main pipe 45 reaches the third check valve 43 through the liquid receiver 46 and the main expansion valve 47 and flows into the liquid pipe 61 from here. The refrigerant that has flowed into the liquid pipe 61 passes through the heat storage valve 55 and the second pipe 53 and flows into the heat storage coil 51, where it evaporates and makes ice in the heat storage tank 50.
[0021]
The refrigerant made into ice in the heat storage tank 50 flows into the gas pipe 60 through the first pipe 52 and the two-way valve 54, and is further returned to the compressor 1 through the four-way valve 2 and the accumulator 4.
[0022]
The cooling operation includes an ice storage utilization cooling operation using ice making shown in FIG. 2 in addition to the ice storage non-use cooling operation shown in FIG.
[0023]
In this use cooling operation, refrigerant control is performed as shown in FIG. That is, the refrigerant compressed by the compressor 1 flows into the bridge circuit 40 through the four-way valve 2 and the outdoor heat exchanger 3, and the first check valve 41, the main pipe 45, and the liquid receiver of the bridge circuit 40. After passing through 46, one flows into the third pipe 63 and the other flows through the main pipe 45 as it is to the main expansion valve 47.
[0024]
The refrigerant flowing into the third pipe 63 enters the heat storage coil 51 in the heat storage tank 50 through the ice-melting valve 56 and the check valve 57. The refrigerant is supercooled by ice in the heat storage coil 51, and then flows into the liquid pipe 61 through the heat storage valve 55 through the second pipe 53. In addition, the refrigerant that has directly flowed into the main expansion valve 47 through the liquid receiver 46 of the bridge circuit 40 flows into the liquid pipe 61 through the third check valve 43.
[0025]
In the liquid pipe 61, the refrigerant supercooled via the heat storage coil 51 and the refrigerant passed through the main expansion valve 47 merge, and the merged refrigerant passes through the indoor expansion valve 21 and heats the indoor unit 30. It flows into the exchanger 31. In the indoor heat exchanger 31, the refrigerant evaporates, thereby cooling the room. The refrigerant passing through the indoor heat exchanger 31 passes through the gas pipe 60, passes through the four-way valve 2 and the accumulator 4, and is returned to the suction pipe of the compressor 1.
[0026]
In this case, in this embodiment, the cooling efficiency can be improved by the amount that the refrigerant is supercooled in the heat storage tank 50.
[0027]
In the above configuration, heating operation is possible. In this heating operation, the flow of the refrigerant is controlled as shown in FIG.
[0028]
That is, the refrigerant discharged to the compressor 1 flows into the gas pipe 60 through the four-way valve 2, flows into the indoor heat exchanger 31 of the indoor unit 30 through the gas pipe 60, and in the indoor heat exchanger 31. Condensation causes the room to be heated. The refrigerant that has passed through the indoor heat exchanger 31 passes through the indoor expansion valve 21, flows into the liquid pipe 61, and further flows into the bridge circuit 40. When entering the bridge circuit 40, the refrigerant flows into the main conduit 45 through the second check valve 42, reaches the fourth check valve 44 through the liquid receiver 46 and the main expansion valve 47, and the fourth check valve 44. It passes through the check valve 44 and flows into the outdoor heat exchanger 3 of the outdoor unit 10. In the outdoor heat exchanger 3, the refrigerant evaporates, and the gasified refrigerant is returned to the compressor 1 through the four-way valve 2 and the accumulator 4.
[0029]
When this heating operation is performed under conditions of extremely low outside air temperature such as during the severe winter season, the fins of the outdoor heat exchanger 3 are frosted. In order to remove the frost formation of the outdoor heat exchanger 3, a defrosting operation is performed.
[0030]
FIG. 5 shows the air defrosting operation. In this defrosting operation, the heating operation is temporarily stopped, the four-way valve 2 is switched to the cooling position, and the compressor 1 is driven. Then, as shown in FIG. 5, the refrigerant compressed by the compressor 1 directly flows into the outdoor heat exchanger 3 through the four-way valve 2, and the outdoor heat exchanger 3 is removed by the hot gas directly flowing into the outdoor heat exchanger 3. Frosted. The refrigerant that has passed through the outdoor heat exchanger 3 is returned to the compressor 1 through a flow similar to that in the cooling operation shown in FIG.
[0031]
FIG. 6 shows a heat storage operation for generating hot water in the heat storage tank. In this heat storage operation, the temperature of the water in the heat storage tank 50 is raised. In this heat storage operation, the refrigerant compressed by the compressor 1 passes through the four-way valve 2 and flows into the gas pipe 60, and from the gas pipe 60 through the two-way valve 54 and the first pipe 52, the heat storage coil 51. Flow into. The refrigerant condenses in the heat storage coil 51 and raises the water temperature in the heat storage tank 50. The refrigerant that has passed through the heat storage coil 51 flows into the bridge circuit 40 through the second pipe 53 and the heat storage valve 55, and the refrigerant that has flowed into the bridge circuit 40 passes through the second check valve 42 to the main pipe 45. Into the fourth check valve 44 through the liquid receiver 46 and the main expansion valve 47.
[0032]
Then, the refrigerant reaches the outdoor heat exchanger 3 of the outdoor unit 10 through the fourth check valve 44, and the evaporated and gasified refrigerant is returned to the compressor 1 through the four-way valve 2 and the accumulator 4.
[0033]
The energy stored in the heat storage tank 50 by this heat storage operation is exclusively used for the hot water defrosting operation as shown in FIG.
[0034]
That is, the refrigerant compressed by the compressor 1 flows into the outdoor heat exchanger 3 through the four-way valve 2, condenses in the outdoor heat exchanger 3, and removes frost attached to the fins of the outdoor heat exchanger 3. Remove. The refrigerant that has passed through the outdoor heat exchanger 3 enters the bridge circuit 40, passes through the first check valve 41, the main pipe 45, the liquid receiver 46, and the main expansion valve 47 of the bridge circuit 40, and then enters the third check valve 43. From here, it passes through the heat storage valve 55 and the second pipe 53 and flows into the heat storage coil 51.
[0035]
In the heat storage coil 51, the refrigerant takes heat from the heat storage energy in the heat storage tank 50, so-called refrigerant is heated, and reaches the two-way valve 54 via the first pipe 52. Then, the gas pipe 60 enters from the two-way valve 54 and is returned to the compressor 1 through the four-way valve 2 and the accumulator 4.
[0036]
In this defrosting operation using hot water, since the refrigerant is heated in the heat storage tank 50 and returned to the compressor 1, the efficiency of the defrosting operation is improved, and the defrosting operation is compared with the defrosting operation of FIG. It can be completed in a short time.
[0037]
In this embodiment, as shown in FIGS. 1 to 7, the refrigerant passing through the main pipe 45 of the bridge circuit 40 first enters the liquid receiver 46 and passes through the main expansion valve 47 in any operation mode. To. Therefore, the main expansion valve 47 is the only expansion valve whose valve opening should be controlled during cooling operation or heating operation. In addition, during the cooling operation using ice heat storage, auxiliary adjustment of the refrigerant flow rate is performed in the main expansion valve 47. In the air conditioner 100 having the heat storage tank 50, the refrigerant charging amount in the refrigeration cycle is large. Therefore, in any operation, excessive liquid refrigerant stays in the liquid pipe 61 by reducing the opening degree of the main expansion valve 47. This excess refrigerant is stored in a liquid receiver 46 located upstream of the main expansion valve 47.
[0038]
In the above configuration, when performing the cooling operation as in the conventional case, when the outdoor expansion valve is opened, the valve opening degree of the indoor expansion valve is controlled, and on the contrary, the heating operation is performed. In the state where the indoor expansion valve is opened, control for reducing the valve opening degree of the outdoor expansion valve, etc. becomes unnecessary. As a result, in the conventional configuration, at least two expansion valves are required. The main expansion valve 47 can be used, the number of expansion valves can be reduced, and the cost can be reduced. During cooling operation using ice heat storage, pressure reduction and flow rate adjustment are performed by two expansion valves.
[0039]
In the above configuration, the pressure equalizing pipe 48 is led out from the upper part of the liquid receiver 46 of the bridge circuit 40, and the pressure equalizing pipe 48 is connected downstream of the main expansion valve 47. In general, when the operation of the air conditioner 100 is stopped, a low-pressure gas refrigerant region and a high-pressure liquid refrigerant region are formed before and after the main expansion valve 47 as a boundary. Conventionally, the expansion valve is opened to equalize the pressure in each region. When this is done, a large amount of liquid refrigerant flows into the low-pressure gas refrigerant region when the compressor 1 is restarted, and the liquid back to the compressor 1 is reduced. Wake up. Conventionally, the accumulator 4 has a large capacity (for example, 7.5 liters).
[0040]
In order to eliminate the liquid back to the compressor 1, in the above configuration, when the operation of the air conditioner 100 is stopped, the main expansion valve 47 is closed and the pressure equalizing valve 49 of the pressure equalizing pipe 48 is opened. Thereby, the pipes before and after the main expansion valve 47 communicate with each other through the pressure equalizing pipe 48, and the pressure before and after the main expansion valve 47 is equalized.
[0041]
In this case, since the gas refrigerant stays in the upper part of the liquid receiver 46, even if the pressure equalizing valve 49 of the pressure equalizing pipe 48 is opened, it is the gas refrigerant that moves through the pressure equalizing pipe 48, and the liquid refrigerant moves. There is no. In this case, the capacity of the accumulator 4 can be small (for example, 2.5 liters), and the capacity of the accumulator 4 is the same as that of a so-called general-purpose outdoor unit.
[0042]
In the above configuration, the main expansion valve 47 is incorporated in the bridge circuit 40, and the bridge circuit 40 is accommodated in the heat storage unit 20, and since the indoor expansion valve 21 is accommodated in the heat storage unit 20, the outdoor unit 10 and the indoor unit 30 does not need to accommodate an expansion valve. Further, as described above, the capacity of the accumulator 4 in the outdoor unit 10 is a small capacity (for example, 2.5 liters) like the general-purpose unit. Therefore, a conventional general-purpose outdoor unit that does not incorporate an expansion valve can be used in combination with the heat storage unit 20 of the air conditioner 100 as the outdoor unit 10 of the air conditioner 100.
[0043]
8-14 show another embodiment. 8 to 14 are refrigerant circuit diagrams corresponding to FIGS. 1 to 7, respectively. 8 is different from the embodiment shown in FIG. 1 in the piping system around the heat storage tank 50.
[0044]
One end of the heat storage coil 51 submerged in the heat storage tank 50 is connected to the gas pipe 60 via the first pipe line 52 and the two-way valve 54, and also the first pipe line 52 and the subcool valve 71. The liquid pipe 61 is connected via a check valve 72. The other end of the heat storage coil 51 is connected to the liquid pipe 61, that is, the liquid pipe 61 between the bridge circuit 40 and the indoor expansion valve 21 via the second pipe 53 and the heat storage valve 55. A third pipe line 63 is connected to the main pipe line 45 of the bridge circuit 40 between the liquid receiver 46 and the main expansion valve 47, and the third pipe line 63 is connected to the deicing line. The other end of the above-described heat storage coil 51 is connected via a valve 56 and a check valve 57. Other configurations are substantially the same as those shown in FIG.
[0045]
Next, the operation of this embodiment will be described.
[0046]
In FIG. 8, the flow of the refrigerant at the time of general cooling operation (cooling operation not using ice heat storage) is indicated by a thick line. The refrigerant compressed by the compressor 1 flows into the outdoor heat exchanger 3 through the four-way valve 2 and condenses here. This condensed refrigerant enters the bridge circuit 40. In the bridge circuit 40, the main circuit 45 is entered via the first check valve 41, and the main expansion valve 47 is entered via the liquid receiver 46 connected to the main line 45.
[0047]
Then, after passing through the main expansion valve 47, it goes to the liquid pipe 61 through the third check valve 43, and flows from here through the indoor side expansion valve 21 to the indoor heat exchanger 31 of the indoor unit 30. In the indoor heat exchanger 31, the refrigerant evaporates, takes away latent heat of evaporation from the surroundings, and cools the room. Then, the refrigerant that has passed through the indoor heat exchanger 31 passes through the gas pipe 60 and is returned to the suction pipe of the compressor 1 through the four-way valve 2 and the accumulator 4.
[0048]
In this embodiment, the ice heat storage operation is performed using inexpensive electricity at night. In this ice heat storage operation, the refrigerant flows as shown by the thick line in FIG. That is, the refrigerant compressed by the compressor 1 flows into the bridge circuit 40 through the four-way valve 2 and the outdoor heat exchanger 3, and flows into the main conduit 45 through the first check valve 41 of the bridge circuit 40. To do. The refrigerant flowing into the main pipe 45 reaches the third check valve 43 through the liquid receiver 46 and the main expansion valve 47 and flows into the liquid pipe 61 from here.
[0049]
The refrigerant that has flowed into the liquid pipe 61 passes through the heat storage valve 55 and the second pipe 53 and flows into the heat storage coil 51, where it evaporates and makes ice in the heat storage tank 50. In this case, the subcool valve 71 is fully closed. The refrigerant flow in the heat storage coil 51 during the ice heat storage operation is in the direction of the arrow X.
[0050]
The refrigerant made into ice in the heat storage tank 50 flows into the gas pipe 60 through the first pipe 52 and the two-way valve 54, and is further returned to the compressor 1 through the four-way valve 2 and the accumulator 4.
[0051]
The cooling operation includes an ice storage-use cooling operation using ice making as shown in FIG. 9 in addition to the ice storage non-use cooling operation shown in FIG.
[0052]
In this cooling use operation, refrigerant control is performed as shown in FIG. That is, the refrigerant compressed by the compressor 1 flows into the bridge circuit 40 through the four-way valve 2 and the outdoor heat exchanger 3, and the first check valve 41, the main pipe 45, and the liquid receiver of the bridge circuit 40. After passing through 46, one flows into the third pipe 63 and the other flows through the main pipe 45 as it is to the main expansion valve 47.
[0053]
The refrigerant flowing into the third pipe 63 enters the heat storage coil 51 in the heat storage tank 50 through the ice-melting valve 56 and the check valve 57. The flow of the refrigerant in the heat storage coil 51 during the cooling operation using ice heat storage is in the direction of arrow X.
[0054]
This refrigerant is supercooled by ice in the heat storage coil 51, and then flows into the liquid pipe 61 through the first pipe 52, the subcool valve 71, and the check valve 72. In addition, the refrigerant that has directly flowed into the main expansion valve 47 through the liquid receiver 46 of the bridge circuit 40 flows into the liquid pipe 61 through the third check valve 43.
[0055]
In the liquid pipe 61, the refrigerant supercooled via the heat storage coil 51 and the refrigerant passed through the main expansion valve 47 merge, and the merged refrigerant passes through the indoor expansion valve 21 and heats the indoor unit 30. It flows into the exchanger 31. In the indoor heat exchanger 31, the refrigerant evaporates, thereby cooling the room. The refrigerant passing through the indoor heat exchanger 31 passes through the gas pipe 60, passes through the four-way valve 2 and the accumulator 4, and is returned to the suction pipe of the compressor 1. During the cooling operation using ice heat storage, the indoor expansion valve 21 causes the refrigerant to expand, and the main expansion valve 47 adjusts the refrigerant flow.
[0056]
In this case, in this embodiment, the cooling efficiency can be improved by the amount that the refrigerant is supercooled in the heat storage tank 50.
[0057]
In the above configuration, heating operation is possible. In this heating operation, the flow of the refrigerant is controlled as shown in FIG.
[0058]
That is, the refrigerant discharged to the compressor 1 flows into the gas pipe 60 through the four-way valve 2, flows into the indoor heat exchanger 31 of the indoor unit 30 through the gas pipe 60, and in the indoor heat exchanger 31. Condensation causes the room to be heated. The refrigerant that has passed through the indoor heat exchanger 31 passes through the indoor expansion valve 21, flows into the liquid pipe 61, and further flows into the bridge circuit 40. When entering the bridge circuit 40, the refrigerant flows into the main conduit 45 through the second check valve 42, reaches the fourth check valve 44 through the liquid receiver 46 and the main expansion valve 47, and the fourth check valve 44. It passes through the check valve 44 and flows into the outdoor heat exchanger 3 of the outdoor unit 10. In the outdoor heat exchanger 3, the refrigerant evaporates, and the gasified refrigerant is returned to the compressor 1 through the four-way valve 2, the accumulator 4, and the sub-accumulator 5.
[0059]
When this heating operation is performed under conditions of extremely low outside air temperature such as during the severe winter season, the fins of the outdoor heat exchanger 3 are frosted. In order to remove the frost formation of the outdoor heat exchanger 3, a defrosting operation is performed.
[0060]
FIG. 12 shows the air defrosting operation. In this defrosting operation, the heating operation is temporarily stopped, the four-way valve 2 is switched to the cooling position, and the compressor 1 is driven. Then, as shown in FIG. 12, the refrigerant compressed by the compressor 1 directly flows into the outdoor heat exchanger 3 through the four-way valve 2, and the outdoor heat exchanger 3 is removed by the hot gas directly flowing into the outdoor heat exchanger 3. Frosted. The refrigerant having passed through the outdoor heat exchanger 3 is returned to the compressor 1 through a flow similar to that in the cooling operation shown in FIG.
[0061]
In this case, the operation of the blower fan of the indoor heat exchanger 31 is stopped and the refrigerant is not evaporated. The original requirement is heating operation, so that cold air is not blown into the room during the defrosting operation.
[0062]
FIG. 13 shows a heat storage operation. In this heat storage operation, the temperature of the water in the heat storage tank 50 is raised. In this heat storage operation, the refrigerant compressed by the compressor 1 passes through the four-way valve 2 and flows into the gas pipe 60, and from the gas pipe 60 through the two-way valve 54 and the first pipe 52, the heat storage coil 51. Flow into. The refrigerant condenses in the heat storage coil 51 and raises the water temperature in the heat storage tank 50. The refrigerant that has passed through the heat storage coil 51 flows into the bridge circuit 40 through the second pipe 53 and the heat storage valve 55, and the refrigerant that has flowed into the bridge circuit 40 passes through the second check valve 42 to the main pipe 45. Into the fourth check valve 44 through the liquid receiver 46 and the main expansion valve 47.
[0063]
Then, the refrigerant reaches the outdoor heat exchanger 3 of the outdoor unit 10 through the fourth check valve 44, and the evaporated and gasified refrigerant is returned to the compressor 1 through the four-way valve 2 and the accumulator 4.
[0064]
The energy stored in the heat storage tank 50 by this heat storage operation is exclusively used for the hot water defrosting operation as shown in FIG.
[0065]
That is, the refrigerant compressed by the compressor 1 flows into the outdoor heat exchanger 3 through the four-way valve 2, condenses in the outdoor heat exchanger 3, and removes frost attached to the fins of the outdoor heat exchanger 3. Remove. The refrigerant that has passed through the outdoor heat exchanger 3 enters the bridge circuit 40, passes through the first check valve 41, the main pipe 45, the liquid receiver 46, and the main expansion valve 47 of the bridge circuit 40, and then enters the third check valve 43. From here, it passes through the heat storage valve 55 and the second pipe 53 and flows into the heat storage coil 51.
[0066]
In the heat storage coil 51, the refrigerant takes heat from the heat storage energy in the heat storage tank 50, so-called refrigerant is heated, and reaches the two-way valve 54 via the first pipe 52. Then, the gas pipe 60 enters from the two-way valve 54 and is returned to the compressor 1 through the four-way valve 2 and the accumulator 4.
[0067]
In this defrosting operation using hot water, since the refrigerant is heated in the heat storage tank 50 and returned to the compressor 1, the efficiency of the defrosting operation is improved, and the defrosting operation is compared with the defrosting operation of FIG. It can be completed in a short time.
[0068]
In this embodiment, as shown in FIGS. 8 to 14, the refrigerant passing through the main conduit 45 of the bridge circuit 40 first enters the liquid receiver 46 and passes through the main expansion valve 47 in any operation mode. To. Therefore, the expansion valve whose valve opening should be controlled during the cooling operation or the heating operation is the one main expansion valve 47. Even in any operation, excessive liquid refrigerant stays in the liquid pipe 61 by reducing the valve opening of the main expansion valve 47. This excess refrigerant is stored in a liquid receiver 46 located upstream of the main expansion valve 47.
[0069]
In the above configuration, when performing the cooling operation as in the conventional case, when the outdoor expansion valve is opened, the valve opening degree of the indoor expansion valve is controlled, and on the contrary, the heating operation is performed. In the state where the indoor expansion valve is opened, control for reducing the valve opening degree of the outdoor expansion valve, etc. becomes unnecessary. As a result, in the conventional configuration, at least two expansion valves are required. The main expansion valve 47 can be used, the number of expansion valves can be reduced, and the cost can be reduced.
[0070]
In the above configuration, the pressure equalizing pipe 48 is led out from the upper part of the liquid receiver 46 of the bridge circuit 40, and the pressure equalizing pipe 48 is connected downstream of the main expansion valve 47. In general, when the operation of the air conditioner 100 is stopped, a low-pressure gas refrigerant region and a high-pressure liquid refrigerant region are formed before and after the main expansion valve 47 as a boundary. Conventionally, the expansion valve is opened to equalize the pressure in each region. When this is done, a large amount of liquid refrigerant flows into the low-pressure gas refrigerant region when the compressor 1 is restarted, and the liquid back to the compressor 1 is reduced. Wake up. Conventionally, the accumulator 4 has a large capacity (for example, 7.5 liters).
[0071]
In order to eliminate the liquid back to the compressor 1, in the above configuration, when the operation of the air conditioner 100 is stopped, the main expansion valve 47 is closed and the pressure equalizing valve 49 of the pressure equalizing pipe 48 is opened. Thereby, the pipes before and after the main expansion valve 47 communicate with each other through the pressure equalizing pipe 48, and the pressure before and after the main expansion valve 47 is equalized.
[0072]
In this case, since the gas refrigerant stays in the upper part of the liquid receiver 46, even if the pressure equalizing valve 49 of the pressure equalizing pipe 48 is opened, it is the gas refrigerant that moves through the pressure equalizing pipe 48, and the liquid refrigerant moves. There is no. In this case, the capacity of the accumulator 4 can be small (for example, 2.5 liters), and the capacity of the accumulator 4 is the same as that of a so-called general-purpose outdoor unit.
[0073]
In the above configuration, the main expansion valve 47 is incorporated in the bridge circuit 40, and the bridge circuit 40 is accommodated in the heat storage unit 20, and since the indoor expansion valve 21 is accommodated in the heat storage unit 20, the outdoor unit 10 and the indoor unit 30 does not need to accommodate an expansion valve. Further, as described above, the capacity of the accumulator 4 in the outdoor unit 10 is a small capacity (for example, 2.5 liters) like the general-purpose unit. Therefore, a conventional general-purpose outdoor unit that does not incorporate an expansion valve can be used in combination with the heat storage unit 20 of the air conditioner 100 as the outdoor unit 10 of the air conditioner 100.
[0074]
As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to this. For example, although the air conditioning apparatus 100 is configured with three units of the outdoor unit 10, the heat storage unit 20, and the indoor unit 30, the present invention is not limited to this, and the outdoor unit 10 and the heat storage unit 20 are integrated. Is possible.
[0075]
【The invention's effect】
In the present invention, the number of expansion valves is reduced, the control thereof is simplified, and an air conditioner having a simple configuration is provided.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram during an ice storage non-use cooling operation showing an embodiment of the present invention.
FIG. 2 is a refrigerant circuit diagram at the time of ice heat storage operation showing an embodiment of the present invention.
FIG. 3 is a refrigerant circuit diagram at the time of cooling operation using ice heat storage according to an embodiment of the present invention.
FIG. 4 is a refrigerant circuit diagram during heating operation showing an embodiment of the present invention.
FIG. 5 is a refrigerant circuit diagram during an air defrosting operation showing an embodiment of the present invention.
FIG. 6 is a refrigerant circuit diagram during a heat storage operation showing an embodiment of the present invention.
FIG. 7 is a refrigerant circuit diagram at the time of hot water defrosting operation showing an embodiment of the present invention.
FIG. 8 is a refrigerant circuit diagram at the time of cooling operation not using ice storage and showing another embodiment of the present invention.
FIG. 9 is a refrigerant circuit diagram during ice heat storage operation showing another embodiment of the present invention.
FIG. 10 is a refrigerant circuit diagram at the time of cooling operation using ice heat storage according to another embodiment of the present invention.
FIG. 11 is a refrigerant circuit diagram during heating operation showing another embodiment of the present invention.
FIG. 12 is a refrigerant circuit diagram during an air defrosting operation showing another embodiment of the present invention.
FIG. 13 is a refrigerant circuit diagram during a heat storage operation showing another embodiment of the present invention.
FIG. 14 is a refrigerant circuit diagram at the time of hot water defrosting operation showing another embodiment of the present invention.
FIG. 15 is a diagram showing an open / close state of each valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 10 Outdoor unit 20 Thermal storage unit 30 Indoor unit 31 Indoor heat exchanger 21 Indoor expansion valve 40 Bridge circuits 41-44 First to fourth check valves 45 Main pipe 46 Liquid unit 47 Main expansion valve 48 Pressure equalizing pipe (bypass line)
49 Pressure equalizing valve 50 Thermal storage tank 51 Thermal storage coil 54 Two-way valve 55 Thermal storage valve 56 Deicing valve 60 Gas pipe 61 Liquid pipe 71 Subcool valve

Claims

A compressor, a four-way valve, an outdoor heat exchanger, a heat storage coil placed in a submerged state in a heat storage tank, an indoor expansion valve, and an indoor heat exchanger are connected by a refrigerant pipe, and cooling operation and heat storage are performed by driving the compressor. In an air conditioner that enables ice heat storage operation for generating ice in a tank and ice heat storage cooling operation using the generated ice, at least four between the outdoor heat exchanger and the indoor heat exchanger A check valve, and a bridge circuit having a main line for communicating a set of two check valves among these check valves are connected, and a receiver and a main expansion valve are connected to the main line of the bridge circuit. Are connected in series so that the refrigerant flows in the order of the liquid receiver connected to the main pipe line and the main expansion valve during any of the cooling operation, the ice heat storage operation, and the ice heat storage cooling operation .
One end of the heat storage coil is connected to a main conduit between the receiver and the main expansion valve via an ice-breaking valve, and the other end of the heat storage coil is connected between the bridge circuit and the indoor expansion valve via the heat storage valve. An air conditioner connected to the air conditioner.

Compressor, four-way valve, outdoor heat exchanger are housed in outdoor unit, heat storage coil, bridge circuit, indoor expansion valve are housed in heat storage unit, indoor heat exchanger is housed in indoor unit, refrigerant between each unit The air conditioner according to claim 1, wherein the air conditioner is connected by piping.

The air conditioner according to claim 1 or 2, wherein a pressure equalizing pipe is led out from an upper part of the liquid receiver of the bridge circuit, and the pressure equalizing pipe is connected downstream of the main expansion valve.

Heating operation by the air heat source, Yutaka蓄operation for producing hot water in the thermal storage tank by switching the four-way valve, according to any one of claims 1 to 3, characterized in that to allow the defrosting operation using the hot water Air conditioner.