JP4217547B2

JP4217547B2 - Air conditioner

Info

Publication number: JP4217547B2
Application number: JP2003168211A
Authority: JP
Inventors: 岳志渡部; 清田村; 正徳阿久津; 稔長田; 明寺崎; 浩一小谷
Original assignee: Sanyo Electric Co Ltd; Toshiba Carrier Corp
Current assignee: Sanyo Electric Co Ltd; Toshiba Carrier Corp
Priority date: 2003-06-12
Filing date: 2003-06-12
Publication date: 2009-02-04
Anticipated expiration: 2023-06-12
Also published as: JP2005003290A

Description

【０００１】
【発明の属する技術分野】
本発明は、ヒートポンプ式冷凍サイクルに蓄熱用熱交換器を加え、通常の冷暖房運転の他に、氷蓄熱運転、氷蓄熱利用冷房運転、温蓄運転、蓄熱利用除霜運転等の切換えを可能にした空気調和機に関する。
【０００２】
【従来の技術】
圧縮機、四方切換え弁、室外熱交換器、室外側膨張弁、蓄熱用熱交換器、室内側膨張弁および室内熱交換器を冷媒配管で連通し、上記圧縮機を駆動することにより通常の冷房運転と暖房運転の他に、蓄熱用熱交換器を利用して氷蓄熱運転や、氷蓄熱利用冷房運転等を可能にした空気調和機が知られている（特許文献１参照）。
【０００３】
この種の空気調和機においては、電気料金が割安な深夜に圧縮機を駆動して蓄熱用熱交換器で蓄熱媒体を製氷化する氷蓄熱運転や、蓄熱媒体を温水化する温蓄運転を行う。昼間になってから氷である蓄熱エネルギを利用して冷媒を過冷却状態とする氷蓄熱利用冷房運転を行い、冷房効率の向上を図っている。あるいは、温水である蓄熱エネルギを利用して室外熱交換器を除霜する蓄熱利用除霜運転を行い、除霜効率の向上を図っている。
【０００４】
上記蓄熱用熱交換器は内容積が大きいことが特徴であり、しかも備えた目的が主として冷房時のアンダークール領域の確保を図ることにある。そのため、この熱交換器内部がほとんど満液状態となり、冷凍サイクル全体での冷媒封入量が蓄熱用熱交換器を備えていない通常の冷凍サイクルと比較して多くなる。
【０００５】
特に、氷蓄熱運転や蓄熱利用除霜運転に切換えた際には、上記蓄熱用熱交換器が蒸発器として作用し、冷凍サイクル中の冷媒量が過剰状態となる。そのため、圧縮機への液戻り量が多くなってしまい、液圧縮が発生する虞れがある。
【０００６】
【特許文献１】
特開２００２−３７２３２５号公報
【０００７】
【発明が解決しようとする課題】
その対策として、通常、圧縮機の吸込み側に設けられるアキュームレータを大型化して容量を増大し、圧縮機への液戻り量の低減化を図ることが考えられる。しかしながら、大容量アキュームレータを配置すると、室外機が大型化してしまい据付けスペースの拡大がともなう。また、大容量アキュームレータは圧力損失が大きいので、実際に用いるのは困難視されている。
【０００８】
空気調和機の製造メーカーとしては、可能な限りコストの上昇を抑制するのが必須の条件であり、そのために標準機種を流用し、もしくは標準機種をベースとして蓄熱用熱交換器を備えた空気調和機を開発することで対応を図っている。このベース機種の標準室外機に搭載されるアキュームレータは容量が比較的小さく、標準室外機をそのまま流用することはできない。
【０００９】
そこで、上記した標準室外機に用いられるアキュームレータをもう一基用意して、これを蓄熱ユニットに組み込んで対応する考えもある。しかしながら、暖房運転をなすと蓄熱ユニット内の上記アキュームレータが圧縮機の吐出側になるので、圧縮した冷媒ガスに含まれる圧縮機の潤滑油が上記アキュームレータに溜まってしまう。
【００１０】
そのまま放置すると圧縮機の潤滑油量が不足して焼き付け事故の発生の原因となる。当然、上記アキュームレータに溜まった潤滑油を圧縮機へ戻す油戻し回路が必要となるが、この回路の製作をともなうためにコストに悪影響を及ぼすこととなる。
【００１１】
本発明は上記事情に着目してなされたものであり、その目的とするところは、蓄熱用熱交換器を備えることを前提として、氷蓄熱運転時や蓄熱利用冷房運転時などにおける圧縮機への液冷媒の戻り量の低減化を図り、よって冷凍効率の向上を得られる空気調和機を提供しようとするものである。
【００１２】
【課題を解決するための手段】
上記目的を達成するために本発明の空気調和機は、圧縮機、四方切換え弁、室外熱交換器、蓄熱用膨張弁、蓄熱用熱交換器、室内熱交換器用膨張弁、および室内熱交換器を順次、冷媒管を介して連通する冷凍サイクル回路を備え、圧縮機と四方切換え弁および室外熱交換器等を配置する室外ユニットと、蓄熱媒体を充填し蓄熱用熱交換器を浸漬させた蓄熱槽を配置する蓄熱ユニットと、室内熱交換器を配置する室内ユニットから構成され蓄熱ユニット内に室内ユニットと室外ユニットとを連通するガス側冷媒管を貫通し、このガス側冷媒管に蓄熱用熱交換器から室内熱交換器をバイパスする蓄熱用バイパス管を接続し、蓄熱ユニット内におけるガス側冷媒管の中途部で蓄熱用バイパス管接続部から室外ユニット側までの間の部位に、冷房運転時では冷媒が下部から上部へ流通し、暖房運転時では冷媒が上部から下部へ流通する縦長状筒体からなる補助タンクを具備する。
【００１３】
このような課題を解決する手段を採用することにより、氷蓄熱運転時や蓄熱利用冷房運転時などにおける圧縮機への液冷媒の戻り量が低減化し、よって冷凍効率の向上を得られる。
【００１４】
【発明の実施の形態】
以下、本発明の実施の形態を図面にもとづいて説明する。
図１は、空気調和機の概略構成と、冷凍サイクル回路の構成を説明する図である。
この空気調和機は、室外ユニットＡと、蓄熱ユニットＢおよび室内ユニットＣとから構成される。上記室外ユニットＡは、圧縮機１と、四方切換え弁２と、室外熱交換器３と、アキュームレータ４と、上記圧縮機１や四方切換え弁２および後述する電動部品を駆動制御する制御部（制御手段）５を備えている。
【００１５】
上記蓄熱ユニットＢは、ブリッジ回路６と、蓄熱用熱交換器７と、タンク８および室内熱交換器用膨張弁９（何れも後述する）を備えている。上記室内ユニットＣは、室内熱交換器１０を備えている。
【００１６】
上記圧縮機１、四方切換え弁２、室外熱交換器３、ブリッジ回路６、蓄熱用熱交換器７、室内熱交換器用膨張弁９、室内熱交換器１０および補助タンク８を介して上記四方切換え弁２が順次、冷媒管Ｐを介して連通され、これらで冷凍サイクル回路Ｒが構成される。
【００１７】
上記蓄熱ユニットＢにおけるブリッジ回路６は、第１の逆止弁１１と、第２の逆止弁１２と、第３の逆止弁１３と、第４の逆止弁１４および、これら逆止弁１１〜１４のうちの２つの逆止弁（第１の逆止弁１１と第３の逆止弁１３、第２の逆止弁１２と第４の逆止弁１４）を連通する中央管路１５を備えている。この中央管路１５には、リキッドタンク１６および蓄熱用膨張弁１７が直列に接続されている。
【００１８】
上記ブリッジ管路６の第２の逆止弁１２と第３の逆止弁１３が設けられる管路の接続部ａに、冷媒管Ｐを構成する液側冷媒管Ｐａの一端が接続されていて、この液側冷媒管Ｐａの他端は上記室内熱交換器用膨張弁９を介して上記室内熱交換器１０に接続される。上記室内熱交換器１０の他端には冷媒管Ｐを構成するガス側冷媒管Ｐｂが接続されていて、このガス側冷媒管Ｐｂは蓄熱ユニットＢ内を貫通し、上記室外ユニットＡ内の四方切換え弁２の所定のポートに接続される。
【００１９】
上記蓄熱ユニットＢ内の上記蓄熱用熱交換器７は蓄熱槽１８に収容されていて、この蓄熱槽１８には蓄熱媒体１９が充填される。上記蓄熱媒体１９として、たとえば水が用いられ、上記蓄熱槽１８内にほぼ満タン状態で充填されているので、上記蓄熱用熱交換器７はこの蓄熱媒体１９中に浸漬される。
【００２０】
上記蓄熱用熱交換器７の一端に第１の管路２０が接続されていて、この第１の管路２０は第１の解氷弁２１を介して上記ブリッジ回路６における中央管路１５の第１の逆止弁１１と第２の逆止弁１２が設けられる管路の接続部ｂに接続されている。
第１の管路２０における蓄熱用熱交換器７との接続部と第１の解氷弁２１との間に、第２の管路２２の一端部が接続されている。この第２の管路２２は、第１の蓄熱弁２３を介して上記液側冷媒管Ｐａにおけるブリッジ回路６と室内熱交換器用膨張弁９との間の部位に接続される。
【００２１】
上記液側冷媒管Ｐａにおける第２の管路２２の接続部と室内熱交換器用膨張弁９との間と、上記ガス側冷媒管Ｐｂの中途部とは蓄熱用バイパス管２５によって連通されていて、この蓄熱用バイパス管２５には第２の解氷弁２６と第２の蓄熱弁２７とが直列に設けられる。
上記蓄熱用熱交換器７の他端には第３の管路２８が接続されていて、この第３の管路２８は上記蓄熱用バイパス管２５における第２の解氷弁２６と第２の蓄熱弁２７との間に接続される。
【００２２】
一方、上記蓄熱ユニットＢ内を貫通する上記ガス側冷媒管Ｐｂには、上述したように補助タンク８が設けられる。この補助タンク８が設けられる部位は、ガス側冷媒管Ｐｂにおける上記蓄熱用バイパス管２５が接続する接続部ｃから室外ユニットＡへの突出部ｄとの間の位置に限定される。
【００２３】
そして、後述する冷凍サイクル運転をなした際に、冷房運転時などでは補助タンク８の下部から上部へ冷媒が流れ、暖房運転時などでは補助タンク８の上部から下部へ冷媒が流れるように、タンク８に対するガス側冷媒管Ｐｂの接続形態が限定される。
【００２４】
図２は、本発明の空気調和機を構成する室外ユニットＡと、蓄熱ユニットＢおよび室内ユニットＣの外観を示す斜視図である。
上記室外ユニットＡは、標準空気調和機における標準室外ユニットをそのまま、もしくは一部変更して流用している。筐体３０の前面に上下二段になった吹出し口３１が設けられていて、それぞれにファンガードが嵌め込まれている。筐体３０内にはそれぞれの吹出し口に対向して２台の室外送風機が上下に配置され、さらにこの室外送風機の背面側には上記室外熱交換器３が上下二段になった状態で配置されている。
【００２５】
上記蓄熱ユニットＢは、正面視と側面視および平面視のいずれにおいても矩形状に形成される筐体３２を備えている。この前面側には扉体３３が開閉自在に取付けられていて、メンテナンスの際に内部を開放できるようになっている。なお、この蓄熱ユニットＢの構造については、さらに詳細に説明する。
【００２６】
上記室内ユニットＣは、たとえば被空調室の天井内に筐体３４が埋め込まれる天井埋め込み型であって、この筐体３４の下面開口を閉塞する化粧パネル３５が天井板から露出する。上記筐体３４内には上記室内熱交換器１０と室内送風機が収容され、上記化粧パネル３５の中央部にグリルが嵌め込まれた吸込み口３６と、各周辺部にルーバーを備えた吹出し口３７が設けられる。
【００２７】
図３は、上記蓄熱ユニットＢを分解した斜視図である。上記筐体３２は固定脚が取付けられる底板３３ａと、上記前面扉体３３と、左右側面パネル３３ｂと、背面パネル３３ｃおよび天板３３ｄとの組み合わせ体から構成される。各パネル３３〜３３ｄは全て矩形状に形成され、上記天板３３ｄには点検用蓋４０が着脱自在に取付けられる。
【００２８】
上記筐体３２内部には、前面扉体３３と所定の間隙を存して補強板４１が設けられていて、この補強板４１には上記制御部５に電気的に接続される電気部品組立４２が取付けられる。上記電気部品組立４２には電気部品カバー４３が着脱自在に取付けられる。
上記補強板４１下部には配管固定板４４が取付けられていて、上記室外ユニットＡおよび室内ユニットＣに延出される複数本の冷媒管Ｐを固定保持している。上記前面扉体３３の下部には配管パネル４５が取付けられていて、上記冷媒管Ｐの接続端部を保持している。
【００２９】
上記筐体３２を構成する底板３３ａ上には上記蓄熱槽１８が据付けられる。上記蓄熱槽１８は平面視で円形状をなし、その直径は矩形状に形成される底板３３ａの幅方向寸法よりも若干小さい程度に設計されている。そして、蓄熱槽１８は底板３３ａの背面パネル３３ｃに近接した状態で配置されていて、蓄熱槽１８と上記補強板４１との間には、ある程度の空間スペースが確保されている。
【００３０】
上記蓄熱槽１８の高さ寸法は、筐体３２の高さ寸法よりも若干低い程度であり、蓄熱槽１８上端は天板３３ｄと所定の間隙を存した状態となっている。したがって、蓄熱槽１８と補強板４１との間の空間スペースは、底板３３ａから天板３３ｄに亘り蓄熱槽１８の高さ方向に沿って形成される。
【００３１】
このような空間スペースに、上記ブリッジ回路６や第１の管路〜第３の管路２０，２２，２８および蓄熱用バイパス管２５と、第１，第２の蓄熱弁２３，２７および第１，第２の解氷弁２１，２６と、リキッドタンク１６および補助タンク８等が配置される。ここでは、空間スペースにリキッドタンク１６と補助タンク８が配置されている状態が示されている。
【００３２】
上記リキッドタンク１６は空間スペースの一方の端部に配置されていて、縦長状の筒体から構成される。上記補助タンク８は空間スペースの他方の端部に配置されている縦長状の筒体である。この補助タンク８の高さ寸法は上記リキッドタンク１６の高さ寸法よりも小さく、補助タンク８下端部と底板３３ａとの間にはある程度の間隙を存している。
【００３３】
先に図１で説明した補助タンク８部分を参照すると理解が早いが、補助タンク８の上端に接続されるガス側冷媒管Ｐｂ１は一旦上方へ延出されてから逆Ｕ字状に曲成される。それから、このガス側冷媒管Ｐｂ１は水平に折曲されて蓄熱ユニットＢから突出し、室外ユニットＡにおける四方切換え弁２に接続される。
【００３４】
また、補助タンク８の下端部に接続されるガス側冷媒管Ｐｂ２は、そのまま下方に延長されてから底板３３ａと接触しない位置でＵ字状に曲成される。そして、水平方向から垂直方向に二段状に折曲され、略Ｔ字状をなす接続部ｃから下部側へ延出され、蓄熱ユニットＢから出て室内ユニットＣ内の室内熱交換器１０に連通される。上記Ｔ字状接続部ｃから上部側は、ガス側冷媒管Ｐｂと液側冷媒管Ｐａとを連通する上記蓄熱用バイパス管２５となる。この補助タンク８は、ガス側冷媒管Ｐｂの内径の３倍以上の内径があるとともに、内容積が２リットル以上ある。
【００３５】
つぎに、このようにして構成される空気調和機の作用について説明する。
図４に、蓄熱用熱交換器７を用いることなく冷房作用をなす通常冷房運転時における冷媒の流れを図中実線矢印で示し、蓄熱用熱交換器７により蓄熱槽１８内の蓄熱媒体１９を凍らせる（製氷する）氷蓄熱運転時における冷媒の流れを図中破線矢印で示し、製氷化された蓄熱媒体１９と蓄熱用熱交換器７とを熱交換して冷房運転をなす氷蓄熱利用冷房運転時における冷媒の流れを図中一点鎖線矢印で示している。
【００３６】
はじめに通常冷房運転から説明する。第１の解氷弁２１と第２の解氷弁２６および第１の蓄熱弁２３と第２の蓄熱弁２７は閉成され、蓄熱用膨張弁１７は全開状態で、室内熱交換器用膨張弁９が減圧作用をなすよう制御される。
【００３７】
圧縮機１で圧縮された冷媒は四方切換え弁２を介して室外熱交換器３に導入され凝縮する。凝縮した冷媒は室外ユニットＡから出て蓄熱ユニットＢに入り、ブリッジ回路６に導かれる。このブリッジ回路６では第１の逆止弁１１を介して中央管路１５に入り、リキッドタンク１６と蓄熱用膨張弁１７を介して第３の逆止弁１３から液側冷媒管Ｐａに導かれる。
【００３８】
この液側冷媒管Ｐａに設けられる室内熱交換器用膨張弁９によって減圧化され、蓄熱ユニットＢを出て室内ユニットＣに入り室内熱交換器１０で蒸発する。このとき、室内熱交換器１０に送風される室内空気と熱交換して蒸発潜熱を奪う。再び室内に吹出された熱交換空気は室内を冷房する。
【００３９】
一方、室内熱交換器１０で蒸発した冷媒はガス側冷媒管Ｐｂに導かれ、室内ユニットＣを出て再び蓄熱ユニットＢに入る。蓄熱ユニットＢに導かれる途中で、冷媒は補助タンク８の下部から導入され上部から導出される。このとき、蒸発冷媒と補助タンク８とは互いに何らの作用も及ぼさない。蓄熱ユニットＢを出たガス冷媒は再び室外ユニットＣに入り、四方切換え弁２を介して圧縮機１に吸込まれて上述のサイクルを循環する。
【００４０】
つぎに、氷蓄熱運転について説明する。この氷蓄熱運転は、たとえば夜間に提供される安価な深夜電力を利用して行われる。第１の蓄熱弁２３および第２の蓄熱弁２７は開放され、第１の解氷弁２１および第２の解氷弁２６は閉成されて、蓄熱用膨張弁１７が減圧作用をなすよう制御される。
【００４１】
圧縮機１から吐出される冷媒は、室外熱交換器３−第１の逆止弁１１−リキッドタンク１６−蓄熱用膨張弁１７−第３の逆止弁１３−第１の蓄熱弁２３−蓄熱用熱交換器７の順に導かれる。このとき、上記蓄熱用膨張弁１７で絞り作用が行われ、蓄熱用熱交換器７において冷媒が蒸発し、蓄熱槽１８内に充填された蓄熱媒体１９である水を冷凍して氷に換える。
【００４２】
上記蓄熱用熱交換器７から導出される蒸発冷媒は、第３の管路２８−第２の蓄熱弁２７−ガス側冷媒管Ｐｂ−補助タンク８の順に導かれ、あとは上述の通常冷房運転と同様の作用となる。
【００４３】
つぎに、氷蓄熱利用冷房運転について説明する。このとき、第１の蓄熱弁２３と第２の蓄熱弁２７は閉成され、第１の解氷弁２１と第２の解氷弁２６は開放される。そして、室内熱交換器用膨張弁９とともに蓄熱用膨張弁１７も絞り調整をなすよう制御される。
【００４４】
圧縮機１−室外熱交換器３−第１の逆止弁１１に導かれた冷媒は、接続部ｂにおいて中央管路１５に導かれる冷媒と、第１の管路２０に導かれる冷媒とに分流される。上記中央管路１５から第３の逆止弁１３を介して液側冷媒管Ｐａに導かれる冷媒を蓄熱用膨張弁１７で絞り調整することで、第１の管路２０から第１の解氷弁２１を介して蓄熱用熱交換器７に導かれる冷媒の流通量が設定される。
【００４５】
上記蓄熱用熱交換器７に導かれる冷媒は、既に室外熱交換器３において凝縮しているが、蓄熱槽１８内の製氷化した蓄熱媒体１９と熱交換してさらに冷却され、過冷却（アンダークール）状態となる。この蓄熱用熱交換器７と熱交換した過冷却状態の冷媒は、第２の解氷弁２６を介して液側冷媒管Ｐａに導かれる。
【００４６】
一方、上記中央管路１５の蓄熱用膨張弁１７で絞られた冷媒は第３の逆止弁１３を介して液側冷媒管Ｐａに導かれ、上記蓄熱用熱交換器７で熱交換したあとの冷媒と合流する。これらの冷媒は室内熱交換器用膨張弁９に導かれて減圧化され、室内熱交換器１０で蒸発する。この室内熱交換器１０には過冷却状態の冷媒が導かれるので、通常冷房運転時と比較して、過冷却された分だけ冷房効率の向上化を得られる。
【００４７】
図５に、蓄熱用熱交換器７を用いることなく暖房作用をなす通常暖房運転時における冷媒の流れを図中実線矢印で示し、蓄熱用熱交換器７により蓄熱槽１８内の蓄熱媒体１９を温めて温水化する温水蓄熱運転時における冷媒の流れを図中破線矢印で示し、上記温水を熱源に利用して室外熱交換器３の除霜をなす温水除霜運転時における冷媒の流れを図中一点鎖線矢印で示している。
【００４８】
はじめに、通常暖房運転から説明する。第１の解氷弁２１と第２の解氷弁２６および第１の蓄熱弁２３と第２の蓄熱弁２７は閉成され、蓄熱用膨張弁１７は全開状態で、室内熱交換器用膨張弁９が減圧作用をなすよう制御される。
【００４９】
圧縮機１で圧縮された冷媒は四方切換え弁２を介してガス側冷媒管Ｐｂに導かれ、室外ユニットＡを出て蓄熱ユニットＢに入り、上記補助タンク８の上部から導入され下部から導出される。このとき、補助タンク８はいわゆるバッファとしてガス冷媒を一時集溜し、ある程度のマフラ効果を得られる。
【００５０】
さらに、ガス冷媒は蓄熱ユニットＢを出て室内ユニットＣに入り、室内熱交換器１０で凝縮する。凝縮した冷媒は、室内熱交換器１０に送風される室内空気に対して凝縮熱を放出する。室内熱交換器１０で温度上昇した室内空気が再び室内に送風され、暖房作用をなす。
【００５１】
上記室内熱交換器１０で凝縮した冷媒は、再び蓄熱ユニットＢに入り室内熱交換器用膨張弁９で絞られ減圧化したあと液側冷媒管Ｐａを介してブリッジ回路６に導かれる。第２の逆止弁１２を介して中央管路１５に入り、リキッドタンク１６と蓄熱用膨張弁１７を介して第４の逆止弁１４から再び室外ユニットＡに入る。室外熱交換器３で蒸発し、四方切換え弁２を介して圧縮機１に吸込まれ上述のサイクルを循環する。
【００５２】
つぎに、温水蓄熱運転について説明する。この温水蓄熱運転は、たとえば夜間に提供される安価な深夜電力を利用して行われる。第１の蓄熱弁２３および第２の蓄熱弁２７は開放され、第１の解氷弁２１および第２の解氷弁２６は閉成されて、蓄熱用膨張弁１７が減圧作用をなすよう制御される。
【００５３】
圧縮機１から吐出される冷媒は、四方切換え弁２−補助タンク８−第２の蓄熱弁２７−蓄熱用熱交換器７−第１の蓄熱弁２３−第１の逆止弁１２−リキッドタンク１６−蓄熱用膨張弁１７の順に導かれる。このとき、上記蓄熱用膨張弁１７で絞り作用が行われ、蓄熱用熱交換器７において冷媒が凝縮して蓄熱槽１８内に充填された蓄熱媒体１９である水を温水化する。
上記蓄熱用膨張弁１７から導出される冷媒は、第４の逆止弁１４を介して上記室外熱交換器３に導かれて蒸発し、あとは上述の通常暖房運転と同様の作用となる。
【００５４】
つぎに、温水除霜運転について説明する。上述した温水蓄熱運転で蓄熱槽１８に温蓄されたエネルギは、専ら室外熱交換器３に対する温水除霜に利用される。このとき、第１の蓄熱弁２３と第２の蓄熱弁２７は開放され、第１の解氷弁２１と第２の解氷弁２６は閉成される。また、蓄熱用膨張弁１７のみ減圧作用をなすよう制御される。
【００５５】
冷媒は、圧縮機１から切換えられた四方切換え弁２を介して室外熱交換器３に導かれて凝縮し、この室外熱交換器３を構成するフィンに付着している霜を溶融除去する。室外熱交換器３を出た冷媒は、第１の逆止弁１１−リキッドタンク１６−蓄熱用膨張弁１７−第３の逆止弁１３−第１の蓄熱弁２３−蓄熱用熱交換器７の順に導かれる。
【００５６】
この蓄熱用熱交換器７では冷媒が蓄熱槽１８内の温水（蓄熱媒体１９）の温蓄エネルギから熱を奪い、いわゆる冷媒加熱される。そのあと、第２の蓄熱弁２７を介してタンク８に導かれ、通常冷房運転や氷蓄熱運転および氷蓄熱利用冷房運転と同様のサイクルを循環する。
【００５７】
なお、上記蓄熱用熱交換器７は内容積が大きく、かつアンダークール確保をなすため、この内部がほとんど満液状態となり、冷凍サイクル全体での冷媒封入量が多くなっている。上記氷蓄熱運転、温水除霜運転のいずれも、蓄熱用熱交換器７が蒸発器として作用するため、冷凍サイクル回路Ｒ中の冷媒量が過剰になり、圧縮機１への液戻り量が多い。
【００５８】
本発明では、蓄熱ユニットＢ内におけるガス側冷媒管Ｐｂに補助タンク８を備えたことを特徴の一つとしている。
たとえば、上述の氷蓄熱運転時において、蓄熱用熱交換器７で蒸発した冷媒は、補助タンク８に導かれ、ここに一旦溜められる。
しかも、冷媒は縦長状の筒体からなる補助タンク８の下部から上部に導かれるようになっているので、蒸発冷媒を構成する液相分が補助タンク８に効率よく溜められ、圧縮機１への液戻りがほとんどなくなる。圧縮機１において液圧縮が生じることがなく、液圧縮にともなう多くの事故の発生を未然に阻止する。
【００５９】
なお、特に蓄熱利用冷房運転時には、室内熱交換器用膨張弁９とともに蓄熱用膨張弁１７の開度が制御部５で制御され、それぞれに流通する冷媒の絞り量が最適状態に保持されている。そして、蓄熱利用冷房運転が終了した状態で制御部５に停止指令が入ると、制御部５は圧縮機１に停止制御信号を送って停止する。
【００６０】
この停止状態では、圧縮機１と室内熱交換器用膨張弁９までの高圧側と、室内熱交換器用膨張弁９から圧縮機１までの低圧側を均圧化して、再度の冷凍サイクル運転の開始指令が入ったときに圧縮機１が円滑に起動するようにしなければならない。
【００６１】
上述した蓄熱利用冷房運転では、上記蓄熱用熱交換器７が凝縮器として作用し液冷媒で満たされているとともに、冷凍サイクル回路Ｒに占める蓄熱用熱交換器７の冷媒収容量が室内熱交換器１０と比較して極めて大であり、運転を停止すると、均圧作用により蓄熱用熱交換器７内の多量で高圧の液冷媒が圧縮機１の吸込み側へ戻る恐れがある。
【００６２】
そこで、上記制御部５は図６に示すような制御をなすように設定されている。すなわち、氷蓄熱利用冷房運転の指令信号が入っている状態では、圧縮機１に対して通常の駆動制御がなされ、蓄熱用膨張弁１７と、室内熱交換器用膨張弁９は絞り制御がなされ、第１，第２の解氷弁２１，２６はいずれも開放され、第１，第２の蓄熱弁２３，２７はいずれも閉成されて、上述のごとき氷蓄熱利用冷房運転が行われている。
【００６３】
停止指令が入ると、制御部５は圧縮機１に対して停止信号を送り、蓄熱用膨張弁１７と室内熱交換器用膨張弁９を全開状態とする制御信号を出す。第１，第２の解氷弁２１，２６には閉成信号を送り、第１，第２の蓄熱弁２３，２７には引き続き閉成信号を送る。ただし、蓄熱用膨張弁１７と室内熱交換器用膨張弁９および第１の蓄熱弁２３に対する制御信号は所定時間（たとえば、２分２０秒）だけ継続する。
【００６４】
この所定時間内では、蓄熱用熱交換器１７に連通する全ての弁（第１，第２の解氷弁２１，２６、第１，第２の蓄熱弁２３，２７）が閉成されて、蓄熱用熱交換器１７に高圧液冷媒をそのまま封じ込めておく。
その一方で、蓄熱用膨張弁１７と室内熱交換器用膨張弁９が全開状態にあるから、高圧側にある室外熱交換器３の高圧冷媒が室内熱交換機用膨張弁９から低圧側に導かれ、上記圧縮機１の吸込み側（低圧側）と吐出側（高圧側）における均圧化がなされる。
【００６５】
所定時間の経過後は、制御部５は蓄熱用膨張弁１７と室内熱交換器用膨張弁９および第１の蓄熱弁２３に対して、それまでとは逆の制御信号を送り、その他の部品については継続して同じ制御信号を送る。すなわち、蓄熱用膨張弁１７と室内熱交換器用膨張弁９は全閉状態とし、第１の蓄熱弁２３を開放するよう切換える。
【００６６】
したがって、蓄熱用熱交換器７に充満していた高圧の液冷媒が、第１の蓄熱弁２３および第２の逆止弁１２を介してリキッドタンク１６に導かれる。第１の蓄熱弁２３に対する開放信号を所定時間（たとえば、８分）だけ継続すれば、蓄熱用熱交換器７にあった高圧液冷媒のほとんど大部分がリキッドタンク１６に移動し、よって蓄熱用熱交換器７における均圧がなされる。
【００６７】
このようにして、第１段目均圧として室内熱交換器用膨張弁９の全開による圧縮機１に対する高圧側と低圧側の均圧化をなし、第２段目均圧として第１の蓄熱弁２３のみの開放による蓄熱用熱交換器７に対する均圧化の２段階制御をなすことにより、停止中に液冷媒の多くをリキッドタンク１６に保持することができる。そのため、再度の運転指令が入った状態で圧縮機１への液戻りが低減化される。
【００６８】
なお、特に蓄熱ユニットＢを平面視で矩形状の筐体３２に成形し、この内部に平面視で略丸型状の蓄熱槽１８を収容して、残りのスペースに上記タンク８とリキッドタンク１６を配置するようにしたから、必然的に形成される筐体３２内の空間スペースを有効利用できる。
【００６９】
【発明の効果】
以上説明したように本発明によれば、蓄熱用熱交換器を備えることを前提として、氷蓄熱運転時や蓄熱利用冷房運転時などにおける圧縮機への液冷媒の戻り量の軽減化を図り、よって冷凍効率の向上を得られる効果を奏する。
【図面の簡単な説明】
【図１】本発明の一実施の形態における、空気調和機の冷凍サイクル構成図。
【図２】同実施の形態に係る、空気調和機を構成する各ユニットの外観斜視図。
【図３】同実施の形態に係る、蓄熱ユニットの分解した斜視図。
【図４】同実施の形態に係る、通常冷房運転と、氷蓄熱運転および氷蓄熱利用冷房運転時における、冷媒の流れを説明する図。
【図５】同実施の形態に係る、通常暖房運転と、温水蓄熱運転および温水除霜運転時における、冷媒の流れを説明する図。
【図６】同実施の形態に係る、２段階均圧制御を説明する図。
【符号の説明】
１…圧縮機、３…室外熱交換器、１７…蓄熱用膨張弁、７…蓄熱用熱交換器、９…室内熱交換器用膨張弁、１０…室内熱交換器、Ａ…室外ユニット、１８…蓄熱槽、Ｂ…蓄熱ユニット、Ｃ…室内ユニット、Ｐｂ…ガス側冷媒管、２５…蓄熱用バイパス管、８…タンク、５…制御部（制御手段）、３２…筐体。[0001]
BACKGROUND OF THE INVENTION
The present invention adds a heat storage heat exchanger to the heat pump refrigeration cycle, and allows switching between ice heat storage operation, ice heat storage cooling operation, heat storage operation, heat storage defrost operation, etc. in addition to normal air conditioning operation. Related to the air conditioner.
[0002]
[Prior art]
A compressor, a four-way switching valve, an outdoor heat exchanger, an outdoor expansion valve, a heat storage heat exchanger, an indoor expansion valve, and an indoor heat exchanger are connected by a refrigerant pipe, and normal cooling is performed by driving the compressor. In addition to operation and heating operation, there is known an air conditioner that enables ice storage operation, cooling operation using ice storage, and the like using a heat storage heat exchanger (see Patent Document 1).
[0003]
In this type of air conditioner, an ice heat storage operation in which the compressor is driven at midnight when electricity charges are cheap and the heat storage medium is made into ice by a heat storage heat exchanger or a heat storage operation in which the heat storage medium is warmed is performed. . After the daytime, the cooling operation using ice storage is performed by using the heat storage energy that is ice to make the refrigerant supercooled, thereby improving the cooling efficiency. Or the thermal storage defrost operation which defrosts an outdoor heat exchanger using the thermal storage energy which is warm water is performed, and the improvement of defrost efficiency is aimed at.
[0004]
The heat storage heat exchanger is characterized by a large internal volume, and its purpose is to mainly secure an undercool region during cooling. Therefore, the inside of the heat exchanger is almost full, and the amount of refrigerant enclosed in the entire refrigeration cycle is larger than that in a normal refrigeration cycle that does not include a heat storage heat exchanger.
[0005]
In particular, when switching to an ice heat storage operation or a heat storage defrosting operation, the heat storage heat exchanger acts as an evaporator, and the amount of refrigerant in the refrigeration cycle becomes excessive. For this reason, the amount of liquid returned to the compressor increases, and liquid compression may occur.
[0006]
[Patent Document 1]
JP 2002-372325 A
[0007]
[Problems to be solved by the invention]
As a countermeasure, it is conceivable to normally increase the capacity of the accumulator provided on the suction side of the compressor to increase the capacity and reduce the amount of liquid returned to the compressor. However, when a large-capacity accumulator is arranged, the outdoor unit becomes large and the installation space increases. In addition, a large-capacity accumulator has a large pressure loss, so that it is considered difficult to actually use it.
[0008]
As a manufacturer of air conditioners, it is indispensable to suppress the increase in cost as much as possible. To that end, standard models are diverted or air conditioners equipped with heat exchangers for heat storage based on standard models. We are trying to cope with this by developing a machine. The accumulator mounted on the standard outdoor unit of this base model has a relatively small capacity, and the standard outdoor unit cannot be used as it is.
[0009]
Therefore, there is an idea to prepare another accumulator for use in the standard outdoor unit described above and incorporate this into the heat storage unit to cope with it. However, when the heating operation is performed, the accumulator in the heat storage unit becomes the discharge side of the compressor, and therefore, the lubricant oil of the compressor contained in the compressed refrigerant gas is accumulated in the accumulator.
[0010]
If left as it is, the amount of lubricating oil in the compressor will be insufficient, causing a burning accident. Naturally, an oil return circuit for returning the lubricating oil accumulated in the accumulator to the compressor is required, but the production of this circuit will adversely affect the cost.
[0011]
The present invention has been made paying attention to the above circumstances, and the purpose of the present invention is to provide a compressor in an ice heat storage operation or a heat storage-use cooling operation on the premise that a heat storage heat exchanger is provided. An object of the present invention is to provide an air conditioner capable of reducing the return amount of the liquid refrigerant and thus improving the refrigeration efficiency.
[0012]
[Means for Solving the Problems]
To achieve the above object, an air conditioner according to the present invention includes a compressor, a four-way switching valve, an outdoor heat exchanger, a heat storage expansion valve, a heat storage heat exchanger, an indoor heat exchanger expansion valve, and an indoor heat exchanger. Are equipped with a refrigeration cycle circuit that sequentially communicates through a refrigerant pipe, an outdoor unit in which a compressor, a four-way switching valve, an outdoor heat exchanger and the like are arranged, and a heat storage medium filled with a heat storage medium and immersed in a heat storage heat exchanger A heat storage unit in which the tank is disposed and an indoor unit in which the indoor heat exchanger is disposed. The heat storage unit passes through the gas side refrigerant pipe that communicates the indoor unit and the outdoor unit, and heat is stored in the gas side refrigerant pipe. A heat storage bypass pipe that bypasses the indoor heat exchanger from the exchanger is connected, and a cooling operation is performed in the middle part of the gas side refrigerant pipe in the heat storage unit between the heat storage bypass pipe connection and the outdoor unit side. In the refrigerant flows from bottom to top, comprises an auxiliary tank consisting of vertically elongated cylindrical body that flows into the lower refrigerant from the top in the heating operation.
[0013]
By adopting a means for solving such a problem, the return amount of the liquid refrigerant to the compressor at the time of ice heat storage operation or heat storage use cooling operation is reduced, thereby improving the refrigeration efficiency.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a schematic configuration of an air conditioner and a configuration of a refrigeration cycle circuit.
This air conditioner includes an outdoor unit A, a heat storage unit B, and an indoor unit C. The outdoor unit A includes a compressor 1, a four-way switching valve 2, an outdoor heat exchanger 3, an accumulator 4, a controller that controls driving of the compressor 1, the four-way switching valve 2, and an electric component described later (control). Means) 5 is provided.
[0015]
The heat storage unit B includes a bridge circuit 6, a heat storage heat exchanger 7, a tank 8, and an indoor heat exchanger expansion valve 9 (all of which will be described later). The indoor unit C includes an indoor heat exchanger 10.
[0016]
The four-way switching is performed via the compressor 1, the four-way switching valve 2, the outdoor heat exchanger 3, the bridge circuit 6, the heat storage heat exchanger 7, the indoor heat exchanger expansion valve 9, the indoor heat exchanger 10 and the auxiliary tank 8. The valves 2 are sequentially communicated via the refrigerant pipe P, and these constitute the refrigeration cycle circuit R.
[0017]
The bridge circuit 6 in the heat storage unit B includes a first check valve 11, a second check valve 12, a third check valve 13, a fourth check valve 14, and these check valves. A central pipeline that communicates two check valves 11 to 14 (first check valve 11 and third check valve 13, second check valve 12 and fourth check valve 14). 15 is provided. A liquid tank 16 and a heat storage expansion valve 17 are connected in series to the central pipeline 15.
[0018]
One end of a liquid side refrigerant pipe Pa constituting the refrigerant pipe P is connected to a connection portion a of the pipe line in which the second check valve 12 and the third check valve 13 of the bridge pipe line 6 are provided. The other end of the liquid side refrigerant pipe Pa is connected to the indoor heat exchanger 10 through the indoor heat exchanger expansion valve 9. A gas side refrigerant pipe Pb constituting a refrigerant pipe P is connected to the other end of the indoor heat exchanger 10, and the gas side refrigerant pipe Pb passes through the heat storage unit B, and is connected to the four sides of the outdoor unit A. It is connected to a predetermined port of the switching valve 2.
[0019]
The heat storage heat exchanger 7 in the heat storage unit B is accommodated in a heat storage tank 18, and the heat storage tank 18 is filled with a heat storage medium 19. As the heat storage medium 19, for example, water is used, and the heat storage tank 18 is filled in a substantially full state. Therefore, the heat storage heat exchanger 7 is immersed in the heat storage medium 19.
[0020]
A first pipe line 20 is connected to one end of the heat storage heat exchanger 7, and the first pipe line 20 is connected to the central pipe line 15 in the bridge circuit 6 via a first deicing valve 21. The first check valve 11 and the second check valve 12 are connected to a connection portion b of a pipe line provided.
One end of the second pipe line 22 is connected between the connection part of the first pipe line 20 with the heat storage heat exchanger 7 and the first ice-breaking valve 21. The second pipe line 22 is connected to a portion between the bridge circuit 6 and the indoor heat exchanger expansion valve 9 in the liquid side refrigerant pipe Pa through the first heat storage valve 23.
[0021]
Between the connection part of the 2nd pipe line 22 in the said liquid side refrigerant pipe Pa and the expansion valve 9 for indoor heat exchangers, and the middle part of the said gas side refrigerant pipe Pb are connected by the heat storage bypass pipe 25. The heat storage bypass pipe 25 is provided with a second ice melting valve 26 and a second heat storage valve 27 in series.
A third pipe 28 is connected to the other end of the heat storage heat exchanger 7, and the third pipe 28 is connected to the second deicing valve 26 and the second defrost valve 26 in the heat storage bypass pipe 25. It is connected between the heat storage valve 27.
[0022]
On the other hand, as described above, the auxiliary tank 8 is provided in the gas side refrigerant pipe Pb penetrating the heat storage unit B. The part where the auxiliary tank 8 is provided is limited to a position between the connection part c connected to the heat storage bypass pipe 25 in the gas side refrigerant pipe Pb and the projecting part d to the outdoor unit A.
[0023]
When the refrigeration cycle operation described below is performed, the tank flows so that the refrigerant flows from the lower part to the upper part of the auxiliary tank 8 during the cooling operation and the refrigerant flows from the upper part to the lower part of the auxiliary tank 8 during the heating operation. The connection form of the gas side refrigerant pipe Pb with respect to 8 is limited.
[0024]
FIG. 2 is a perspective view showing the appearance of the outdoor unit A, the heat storage unit B, and the indoor unit C that constitute the air conditioner of the present invention.
The outdoor unit A is diverted from the standard outdoor unit in the standard air conditioner as it is or partly changed. A blowout port 31 is provided in two stages on the front surface of the housing 30, and a fan guard is fitted in each. Two outdoor fans are arranged vertically in the housing 30 so as to face the respective outlets. Further, the outdoor heat exchanger 3 is arranged in two stages on the back side of the outdoor fan. Has been.
[0025]
The heat storage unit B includes a housing 32 that is formed in a rectangular shape in any of a front view, a side view, and a plan view. A door 33 is attached to the front side so as to be freely opened and closed so that the interior can be opened during maintenance. The structure of the heat storage unit B will be described in more detail.
[0026]
The indoor unit C is, for example, a ceiling-embedded type in which a casing 34 is embedded in the ceiling of an air-conditioned room, and a decorative panel 35 that closes the lower surface opening of the casing 34 is exposed from the ceiling plate. The casing 34 accommodates the indoor heat exchanger 10 and the indoor blower, and includes a suction port 36 in which a grille is fitted in the central portion of the decorative panel 35, and a blowout port 37 having a louver in each peripheral portion. Provided.
[0027]
FIG. 3 is an exploded perspective view of the heat storage unit B. As shown in FIG. The housing 32 includes a combination of a bottom plate 33a to which fixed legs are attached, the front door body 33, left and right side panels 33b, a back panel 33c and a top plate 33d. The panels 33 to 33d are all formed in a rectangular shape, and the inspection lid 40 is detachably attached to the top plate 33d.
[0028]
A reinforcing plate 41 is provided inside the housing 32 with a predetermined gap from the front door body 33, and an electrical component assembly 42 electrically connected to the control unit 5 is provided on the reinforcing plate 41. Is installed. An electric component cover 43 is detachably attached to the electric component assembly 42.
A pipe fixing plate 44 is attached to the lower portion of the reinforcing plate 41 and holds a plurality of refrigerant pipes P extending to the outdoor unit A and the indoor unit C. A piping panel 45 is attached to the lower part of the front door 33 and holds the connection end of the refrigerant pipe P.
[0029]
The heat storage tank 18 is installed on the bottom plate 33 a constituting the housing 32. The heat storage tank 18 has a circular shape in plan view, and the diameter thereof is designed to be slightly smaller than the width direction dimension of the bottom plate 33a formed in a rectangular shape. And the heat storage tank 18 is arrange | positioned in the state close | similar to the back panel 33c of the bottom plate 33a, and a certain amount of space space is ensured between the heat storage tank 18 and the said reinforcement board 41. FIG.
[0030]
The height dimension of the heat storage tank 18 is slightly lower than the height dimension of the housing 32, and the upper end of the heat storage tank 18 is in a state where a predetermined gap is left with the top plate 33d. Accordingly, a space between the heat storage tank 18 and the reinforcing plate 41 is formed along the height direction of the heat storage tank 18 from the bottom plate 33a to the top plate 33d.
[0031]
In such a space, the bridge circuit 6, the first to third pipes 20, 22, and 28, the heat storage bypass pipe 25, the first and second heat storage valves 23 and 27, and the first pipe. , Second deicing valves 21, 26, a liquid tank 16, an auxiliary tank 8, and the like are arranged. Here, a state in which the liquid tank 16 and the auxiliary tank 8 are arranged in the space is shown.
[0032]
The liquid tank 16 is disposed at one end of the space and is composed of a vertically long cylindrical body. The auxiliary tank 8 is a vertically long cylinder disposed at the other end of the space. The height dimension of the auxiliary tank 8 is smaller than the height dimension of the liquid tank 16, and a certain gap exists between the lower end portion of the auxiliary tank 8 and the bottom plate 33a.
[0033]
Although it is easy to understand by referring to the auxiliary tank 8 described above with reference to FIG. 1, the gas side refrigerant pipe Pb1 connected to the upper end of the auxiliary tank 8 is once extended upward and then bent into an inverted U shape. The Then, the gas side refrigerant pipe Pb1 is bent horizontally, protrudes from the heat storage unit B, and is connected to the four-way switching valve 2 in the outdoor unit A.
[0034]
Further, the gas side refrigerant pipe Pb2 connected to the lower end portion of the auxiliary tank 8 is bent in a U shape at a position where it does not contact the bottom plate 33a after extending downward as it is. And it is bent in two steps from the horizontal direction to the vertical direction, extends from the connection portion c having a substantially T-shape to the lower side, exits from the heat storage unit B, and enters the indoor heat exchanger 10 in the indoor unit C. Communicated. The upper side from the T-shaped connection part c is the heat storage bypass pipe 25 that communicates the gas side refrigerant pipe Pb and the liquid side refrigerant pipe Pa. The auxiliary tank 8 has an inner diameter that is at least three times the inner diameter of the gas-side refrigerant pipe Pb, and has an internal volume of 2 liters or more.
[0035]
Next, the operation of the air conditioner configured as described above will be described.
In FIG. 4, the flow of the refrigerant during normal cooling operation that performs cooling without using the heat storage heat exchanger 7 is indicated by a solid line arrow in the figure, and the heat storage medium 19 in the heat storage tank 18 is moved by the heat storage heat exchanger 7. The flow of the refrigerant during the ice heat storage operation to be frozen (ice making) is indicated by a broken-line arrow in the figure, and the ice storage-based cooling that performs the cooling operation by exchanging heat between the ice storage heat storage medium 19 and the heat storage heat exchanger 7 is performed. The flow of the refrigerant during operation is indicated by a one-dot chain line arrow in the figure.
[0036]
First, the normal cooling operation will be described. The first ice-breaking valve 21, the second ice-breaking valve 26, the first heat storage valve 23, and the second heat storage valve 27 are closed, the heat storage expansion valve 17 is fully opened, and the indoor heat exchanger expansion valve 9 is controlled to perform a pressure reducing action.
[0037]
The refrigerant compressed by the compressor 1 is introduced into the outdoor heat exchanger 3 through the four-way switching valve 2 and condensed. The condensed refrigerant exits from the outdoor unit A, enters the heat storage unit B, and is guided to the bridge circuit 6. In this bridge circuit 6, it enters the central pipe line 15 through the first check valve 11, and is led from the third check valve 13 to the liquid refrigerant pipe Pa through the liquid tank 16 and the heat storage expansion valve 17. .
[0038]
The pressure is reduced by the indoor heat exchanger expansion valve 9 provided in the liquid side refrigerant pipe Pa, exits the heat storage unit B, enters the indoor unit C, and evaporates in the indoor heat exchanger 10. At this time, heat is exchanged with indoor air blown to the indoor heat exchanger 10 to take away latent heat of evaporation. The heat exchange air blown into the room again cools the room.
[0039]
On the other hand, the refrigerant evaporated in the indoor heat exchanger 10 is guided to the gas side refrigerant pipe Pb, exits the indoor unit C, and enters the heat storage unit B again. On the way to the heat storage unit B, the refrigerant is introduced from the lower part of the auxiliary tank 8 and led out from the upper part. At this time, the evaporative refrigerant and the auxiliary tank 8 have no effect on each other. The gas refrigerant that has exited the heat storage unit B enters the outdoor unit C again, and is sucked into the compressor 1 through the four-way switching valve 2 and circulates in the above cycle.
[0040]
Next, ice heat storage operation will be described. This ice heat storage operation is performed using, for example, inexpensive late-night power provided at night. Control is performed such that the first heat storage valve 23 and the second heat storage valve 27 are opened, the first ice-breaking valve 21 and the second ice-breaking valve 26 are closed, and the heat-storage expansion valve 17 performs a pressure reducing action. Is done.
[0041]
The refrigerant discharged from the compressor 1 is an outdoor heat exchanger 3-a first check valve 11-a liquid tank 16-a heat storage expansion valve 17-a third check valve 13-a first heat storage valve 23-a heat storage. It is led in order of the heat exchanger 7 for use. At this time, a throttling action is performed by the heat storage expansion valve 17, the refrigerant evaporates in the heat storage heat exchanger 7, and the water as the heat storage medium 19 filled in the heat storage tank 18 is frozen and changed to ice.
[0042]
The evaporative refrigerant derived from the heat storage heat exchanger 7 is led in the order of the third pipe 28, the second heat storage valve 27, the gas side refrigerant pipe Pb, and the auxiliary tank 8, and then the normal cooling operation described above. It becomes the same effect as.
[0043]
Next, the cooling operation using ice heat storage will be described. At this time, the first heat storage valve 23 and the second heat storage valve 27 are closed, and the first ice-breaking valve 21 and the second ice-breaking valve 26 are opened. The indoor heat exchanger expansion valve 9 and the heat storage expansion valve 17 are also controlled to adjust the throttle.
[0044]
The refrigerant led to the compressor 1-the outdoor heat exchanger 3-the first check valve 11 is divided into a refrigerant led to the central pipe 15 at the connection portion b and a refrigerant led to the first pipe 20. Divided. The refrigerant introduced from the central pipe line 15 to the liquid refrigerant pipe Pa through the third check valve 13 is throttled and adjusted by the heat storage expansion valve 17, so that the first deicing line from the first pipe line 20. A circulation amount of the refrigerant guided to the heat storage heat exchanger 7 through the valve 21 is set.
[0045]
The refrigerant guided to the heat storage heat exchanger 7 is already condensed in the outdoor heat exchanger 3, but is further cooled by exchanging heat with the ice storage heat storage medium 19 in the heat storage tank 18, so (Cool) state. The supercooled refrigerant that has exchanged heat with the heat storage heat exchanger 7 is guided to the liquid-side refrigerant pipe Pa through the second ice-breaking valve 26.
[0046]
On the other hand, after the refrigerant throttled by the heat storage expansion valve 17 of the central pipe 15 is led to the liquid side refrigerant pipe Pa through the third check valve 13 and heat exchange is performed by the heat storage heat exchanger 7. It merges with the refrigerant. These refrigerants are led to the indoor heat exchanger expansion valve 9 to be decompressed and evaporated in the indoor heat exchanger 10. Since the supercooled refrigerant is led to the indoor heat exchanger 10, the cooling efficiency can be improved by the amount of the supercooling compared to the normal cooling operation.
[0047]
In FIG. 5, the flow of the refrigerant at the time of normal heating operation in which heating operation is performed without using the heat storage heat exchanger 7 is indicated by a solid line arrow in the drawing, and the heat storage medium 19 in the heat storage tank 18 is moved by the heat storage heat exchanger 7. The flow of the refrigerant in the warm water heat storage operation for warming and warming is indicated by a broken-line arrow in the figure, and the flow of the refrigerant in the hot water defrost operation in which the outdoor heat exchanger 3 is defrosted using the hot water as a heat source is illustrated. It is indicated by a medium-dot chain line arrow.
[0048]
First, the normal heating operation will be described. The first ice-breaking valve 21, the second ice-breaking valve 26, the first heat storage valve 23, and the second heat storage valve 27 are closed, the heat storage expansion valve 17 is fully opened, and the indoor heat exchanger expansion valve 9 is controlled to perform a pressure reducing action.
[0049]
The refrigerant compressed by the compressor 1 is led to the gas side refrigerant pipe Pb through the four-way switching valve 2, exits the outdoor unit A, enters the heat storage unit B, is introduced from the upper part of the auxiliary tank 8, and is led out from the lower part. The At this time, the auxiliary tank 8 temporarily collects the gas refrigerant as a so-called buffer and can obtain a certain muffler effect.
[0050]
Further, the gas refrigerant exits the heat storage unit B, enters the indoor unit C, and condenses in the indoor heat exchanger 10. The condensed refrigerant releases heat of condensation to the indoor air blown to the indoor heat exchanger 10. The room air whose temperature has risen in the indoor heat exchanger 10 is blown into the room again to perform a heating action.
[0051]
The refrigerant condensed in the indoor heat exchanger 10 enters the heat storage unit B again and is throttled and decompressed by the indoor heat exchanger expansion valve 9 and then guided to the bridge circuit 6 through the liquid side refrigerant pipe Pa. The central line 15 is entered via the second check valve 12, and the outdoor unit A is entered again from the fourth check valve 14 via the liquid tank 16 and the heat storage expansion valve 17. It evaporates in the outdoor heat exchanger 3 and is sucked into the compressor 1 through the four-way switching valve 2 and circulates in the above cycle.
[0052]
Next, the hot water heat storage operation will be described. This hot water heat storage operation is performed using, for example, inexpensive late-night power provided at night. Control is performed such that the first heat storage valve 23 and the second heat storage valve 27 are opened, the first ice-breaking valve 21 and the second ice-breaking valve 26 are closed, and the heat-storage expansion valve 17 performs a pressure reducing action. Is done.
[0053]
The refrigerant discharged from the compressor 1 is a four-way switching valve 2-an auxiliary tank 8-a second heat storage valve 27-a heat storage heat exchanger 7-a first heat storage valve 23-a first check valve 12-a liquid tank. 16-It guide | induces in order of the expansion valve 17 for thermal storage. At this time, a throttling action is performed by the heat storage expansion valve 17, and the water, which is the heat storage medium 19 filled in the heat storage tank 18, is warmed by condensing the refrigerant in the heat storage heat exchanger 7.
The refrigerant led out from the heat storage expansion valve 17 is led to the outdoor heat exchanger 3 through the fourth check valve 14 to evaporate, and the remaining operation is the same as in the normal heating operation.
[0054]
Next, the hot water defrosting operation will be described. The energy stored in the heat storage tank 18 by the hot water heat storage operation described above is exclusively used for hot water defrosting with respect to the outdoor heat exchanger 3. At this time, the first heat storage valve 23 and the second heat storage valve 27 are opened, and the first ice-breaking valve 21 and the second ice-breaking valve 26 are closed. Further, only the heat storage expansion valve 17 is controlled to perform a pressure reducing action.
[0055]
The refrigerant is led to the outdoor heat exchanger 3 via the four-way switching valve 2 switched from the compressor 1 and condensed, and the frost adhering to the fins constituting the outdoor heat exchanger 3 is melted and removed. The refrigerant that has exited the outdoor heat exchanger 3 is a first check valve 11-a liquid tank 16-a heat storage expansion valve 17-a third check valve 13-a first heat storage valve 23-a heat storage heat exchanger 7. In this order.
[0056]
In this heat storage heat exchanger 7, the refrigerant takes heat from the hot energy stored in the hot water (heat storage medium 19) in the heat storage tank 18, and is so-called refrigerant heated. Then, it guide | induces to the tank 8 via the 2nd thermal storage valve 27, and circulates the same cycle as a normal cooling operation, an ice thermal storage operation, and an ice thermal storage utilization cooling operation.
[0057]
The heat storage heat exchanger 7 has a large internal volume and secures undercooling, so that the inside is almost full and the amount of refrigerant enclosed in the entire refrigeration cycle is large. In both the ice heat storage operation and the hot water defrosting operation, the heat storage heat exchanger 7 acts as an evaporator, so the amount of refrigerant in the refrigeration cycle circuit R becomes excessive, and the amount of liquid returned to the compressor 1 is large. .
[0058]
The present invention is characterized in that the auxiliary tank 8 is provided in the gas side refrigerant pipe Pb in the heat storage unit B.
For example, during the above-described ice heat storage operation, the refrigerant evaporated in the heat storage heat exchanger 7 is guided to the auxiliary tank 8 and temporarily stored therein.
Moreover, since the refrigerant is guided from the lower part to the upper part of the auxiliary tank 8 formed of a vertically long cylindrical body, the liquid phase component constituting the evaporating refrigerant is efficiently stored in the auxiliary tank 8 and is supplied to the compressor 1. Almost no liquid return. Liquid compression does not occur in the compressor 1, and the occurrence of many accidents associated with liquid compression is prevented in advance.
[0059]
In particular, during the cooling operation using heat storage, the opening degree of the heat storage expansion valve 17 together with the indoor heat exchanger expansion valve 9 is controlled by the control unit 5, and the throttle amount of the refrigerant flowing through each of them is maintained in an optimum state. Then, when a stop command is input to the control unit 5 in a state where the heat storage use cooling operation has been completed, the control unit 5 sends a stop control signal to the compressor 1 and stops.
[0060]
In this stopped state, the high pressure side from the compressor 1 to the indoor heat exchanger expansion valve 9 and the low pressure side from the indoor heat exchanger expansion valve 9 to the compressor 1 are equalized, and the refrigerating cycle operation is started again. When the command is entered, the compressor 1 must be started smoothly.
[0061]
In the heat storage-use cooling operation described above, the heat storage heat exchanger 7 acts as a condenser and is filled with liquid refrigerant, and the amount of refrigerant stored in the heat storage heat exchanger 7 in the refrigeration cycle circuit R is indoor heat exchange. If the operation is stopped, a large amount of high-pressure liquid refrigerant in the heat storage heat exchanger 7 may return to the suction side of the compressor 1 when the operation is stopped.
[0062]
Therefore, the control unit 5 is set to perform control as shown in FIG. That is, in a state in which a command signal for cooling operation using ice heat storage is entered, normal drive control is performed for the compressor 1, and the expansion valve 17 for heat storage and the expansion valve 9 for indoor heat exchanger are subjected to throttle control, The first and second deicing valves 21 and 26 are both opened, and the first and second heat storage valves 23 and 27 are both closed, and the cooling operation using ice heat storage is performed as described above. .
[0063]
When the stop command is input, the control unit 5 sends a stop signal to the compressor 1 and outputs a control signal for fully opening the heat storage expansion valve 17 and the indoor heat exchanger expansion valve 9. A closing signal is sent to the first and second deicing valves 21 and 26, and a closing signal is sent to the first and second heat storage valves 23 and 27. However, the control signals for the heat storage expansion valve 17, the indoor heat exchanger expansion valve 9 and the first heat storage valve 23 continue for a predetermined time (for example, 2 minutes and 20 seconds).
[0064]
Within this predetermined time, all the valves communicating with the heat storage heat exchanger 17 (first and second deicing valves 21 and 26, first and second heat storage valves 23 and 27) are closed, The high-pressure liquid refrigerant is sealed in the heat storage heat exchanger 17 as it is.
On the other hand, since the heat storage expansion valve 17 and the indoor heat exchanger expansion valve 9 are fully opened, the high-pressure refrigerant in the outdoor heat exchanger 3 on the high-pressure side is led from the indoor heat exchanger expansion valve 9 to the low-pressure side. The pressure equalization is performed on the suction side (low pressure side) and the discharge side (high pressure side) of the compressor 1.
[0065]
After the elapse of a predetermined time, the control unit 5 sends a reverse control signal to the heat storage expansion valve 17, the indoor heat exchanger expansion valve 9 and the first heat storage valve 23, and other components. Continues to send the same control signal. That is, the heat storage expansion valve 17 and the indoor heat exchanger expansion valve 9 are fully closed, and are switched to open the first heat storage valve 23.
[0066]
Therefore, the high-pressure liquid refrigerant that has been filled in the heat storage heat exchanger 7 is guided to the liquid tank 16 via the first heat storage valve 23 and the second check valve 12. If the opening signal for the first heat storage valve 23 is continued for a predetermined time (for example, 8 minutes), most of the high-pressure liquid refrigerant in the heat storage heat exchanger 7 moves to the liquid tank 16, and thus for heat storage. Pressure equalization in the heat exchanger 7 is performed.
[0067]
In this way, pressure equalization on the high pressure side and the low pressure side with respect to the compressor 1 is achieved by fully opening the expansion valve 9 for indoor heat exchanger as the first stage pressure equalization, and the first heat storage valve as the second stage pressure equalization. By performing two-stage control of pressure equalization for the heat storage heat exchanger 7 by opening only 23, most of the liquid refrigerant can be held in the liquid tank 16 during stoppage. Therefore, the liquid return to the compressor 1 is reduced in the state where the operation command is input again.
[0068]
In particular, the heat storage unit B is formed into a rectangular housing 32 in plan view, and a substantially round heat storage tank 18 is accommodated in the housing 32 in the plan view, and the tank 8 and the liquid tank 16 are stored in the remaining space. Therefore, the space space in the housing 32 that is inevitably formed can be effectively used.
[0069]
【The invention's effect】
As described above, according to the present invention, on the assumption that a heat storage heat exchanger is provided, the amount of liquid refrigerant returned to the compressor during the ice heat storage operation or the heat storage cooling operation is reduced. Therefore, there is an effect that an improvement in refrigeration efficiency can be obtained.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a refrigeration cycle of an air conditioner according to an embodiment of the present invention.
FIG. 2 is an external perspective view of each unit constituting the air conditioner according to the embodiment.
FIG. 3 is an exploded perspective view of a heat storage unit according to the embodiment.
FIG. 4 is a view for explaining the refrigerant flow during normal cooling operation, ice heat storage operation, and ice heat storage cooling operation according to the embodiment.
FIG. 5 is a diagram for explaining the refrigerant flow during normal heating operation, hot water heat storage operation, and hot water defrosting operation according to the embodiment;
FIG. 6 is a view for explaining two-stage pressure equalization control according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Compressor, 3 ... Outdoor heat exchanger, 17 ... Heat storage expansion valve, 7 ... Heat storage heat exchanger, 9 ... Indoor heat exchanger expansion valve, 10 ... Indoor heat exchanger, A ... Outdoor unit, 18 ... Thermal storage tank, B ... thermal storage unit, C ... indoor unit, Pb ... gas side refrigerant pipe, 25 ... heat storage bypass pipe, 8 ... tank, 5 ... control unit (control means), 32 ... casing.

Claims

Equipped with a compressor, four-way switching valve, outdoor heat exchanger, heat storage expansion valve, heat storage heat exchanger, indoor heat exchanger expansion valve, and indoor heat exchanger sequentially connected to each other through a refrigerant pipe ,
An outdoor unit that arranges the compressor, a four-way switching valve, an outdoor heat exchanger, and the like, and a heat storage unit that fills the heat storage medium and arranges a heat storage tank in which the heat storage heat exchanger is immersed in the heat storage medium, An air conditioner comprising an indoor unit in which the indoor heat exchanger is disposed,
In the heat storage unit, penetrating a gas side refrigerant pipe communicating the indoor unit and the outdoor unit,
A heat storage bypass pipe that bypasses the indoor heat exchanger from the heat storage heat exchanger is connected to the gas side refrigerant pipe,
During the cooling operation, the refrigerant flows from the lower part to the upper part in the middle part of the gas side refrigerant pipe in the heat storage unit and between the heat storage bypass pipe connection part and the outdoor unit side. Then, the air conditioner characterized by comprising the auxiliary tank which consists of a vertically long cylindrical body with which a refrigerant | coolant distribute | circulates from the upper part to the lower part.

When the cooling operation using the heat storage is stopped, as the first stage pressure equalization, all the valves provided in the conduit communicating with the heat storage heat exchanger are closed and the expansion valve for the indoor heat exchanger is fully opened. Then, pressure equalization is performed between the high pressure side and the low pressure side excluding the heat storage heat exchanger, and then, as the second stage pressure equalization, a predetermined valve is opened to equalize the heat storage heat exchanger. The air conditioner according to claim 1, further comprising control means for equalizing pressure.

The heat storage unit is characterized in that a substantially circular heat storage tank is accommodated in a rectangular housing in plan view, and the auxiliary tank is disposed in the remaining space in the housing. Item 1. An air conditioner according to item 1.