JP3900976B2 - Air conditioner and method of operating air conditioner - Google Patents

Air conditioner and method of operating air conditioner Download PDF

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Publication number
JP3900976B2
JP3900976B2 JP2002060046A JP2002060046A JP3900976B2 JP 3900976 B2 JP3900976 B2 JP 3900976B2 JP 2002060046 A JP2002060046 A JP 2002060046A JP 2002060046 A JP2002060046 A JP 2002060046A JP 3900976 B2 JP3900976 B2 JP 3900976B2
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refrigerant
heat exchanger
liquid
indoor heat
air conditioner
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JP2003262429A (en
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信 齊藤
宗 野本
哲二 七種
史武 畝崎
寿彦 榎本
誠司 井上
正人 四十宮
英治 福島
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Description

【０００１】
【発明の属する技術分野】
この発明は、再熱除湿機能を有する空気調和機および空気調和機の運転方法に関するものである。
【０００２】
【従来の技術】
図８は従来の特許第３１８１４１８号に掲載されている再熱除湿機能を有する空気調和機における冷媒の主な流れを示す冷媒回路図である。図において、１は室外ユニット、２は室内ユニット、３、４は冷媒配管、５は圧縮機、６は四方弁、７は室外熱交換器、８は室外送風機、１２は減圧手段、１５は第１室内熱交換器、１６は減圧手段、１７は第２室内熱交換器、３１は減圧手段１６と並列に設けられた開閉弁である。
【０００３】
以下、再熱除湿運転時の動作について説明する。四方弁６を図８の実線で示すように接続し、かつ、室内ユニット２内の開閉弁３１を閉止する。第１、第２室内熱交換器１５、１７は再熱器１５と蒸発器１７として動作する。
圧縮機５で圧縮された高温高圧のガス冷媒は、四方弁６を経て室外熱交換器７に入り、外気に放熱して所定の乾き度の高圧二相冷媒となる。この冷媒は減圧手段１２を通過するが、再熱除湿運転時にはこの減圧手段１２は全開とされ、ほとんど圧力低下することなく冷媒配管３を通過し、再熱器１５へと導かれる。ここで、室内空気に放熱して凝縮液化し、減圧手段１６によって減圧膨張した後、蒸発器１７で室内空気から吸熱しガス化する。このガス冷媒は冷媒配管４を通過し四方弁６を経て圧縮機５の吸入側に戻る。
室内ユニット２では、蒸発器１７で吸熱されて冷却除湿された空気と再熱器１５で加熱された空気が混合して、室内に再び吹き出される。これにより吸込んだ室内空気はほとんど温度変化せずに除湿のみが行われて室内へ吹き出される。室外ユニット１における室外熱交換器７の伝熱量を小さくするためには、室外送風機８の回転数を小さくするなどの手段がこうじられる。
【０００４】
再熱除湿運転は回路としては冷房運転と同様に冷媒を循環させ、室外熱交換器７での放熱を小さくして液化させず、かつ減圧手段１２を全開あるいは迂回して減圧することなく第１室内熱交換器である再熱器１５に高圧二相冷媒を搬送することで再熱量を得ている。ここで再熱器１５に流入する冷媒が液冷媒になってしまうと、冷媒の潜熱を利用することができず、液冷媒の顕熱分のわずかな再熱量しか得ることができない。このため、再熱除湿運転時は室外ユニット１では極力凝縮させずに高圧のまま再熱器１５に二相冷媒を送ることが、再熱量を得るために必要となる。
【０００５】
また、例えば業務用に用いられる一般の空気調和機では、設置場所の状況に応じて、数ｍから数十ｍの延長配管が用いられるが、通常、設置現場において延長配管長に応じた冷媒量調節の必要がないように、例えば３０ｍの延長配管までは追加充填不要な量の冷媒が予め封入されている。そして、冷凍サイクル中に液溜めを配設し、延長配管が短い場合においては余剰冷媒を液溜めに収容し、適正な冷媒量で運転できるように設計されている。
しかし、再熱除湿運転では凝縮器として作用する室外熱交換器７の出口を二相状態にするため、冷房運転時には室外熱交換器７の出口に存在する過冷却液が不要となり、余剰冷媒が増大する。液溜めにその余剰冷媒を収容できない場合には室内ユニット２内の凝縮器として作用する再熱器１５が余剰冷媒で満たされてしまい、液冷媒の顕熱分しか室内空気の加熱に寄与しない。再熱器１５が充分大きく、余剰液冷媒をすべて収容しても満液とならない場合には、上記のような問題は生じないが、通常は室内熱交換器を２つに分割して一方に再熱機能を持たせており、それほど大きくはできない。このため、再熱器１５が液冷媒で満たされて、顕熱分の再熱量しか得られない。
【０００６】
また、設置場所の延長配管長に応じて冷媒を充填するようにした場合には、予め設置場所の検討した上で冷媒量を充填するか、最大の冷媒量を充填しておいて設置時に適量になるように充填した冷媒を抜くという作業が必要になる。
また、上記の作業を行って設置場所に応じた量の冷媒を冷凍サイクルに循環させたとしても、冷媒の蒸発熱を利用した冷房運転、冷媒の凝縮熱を利用した暖房運転、両者を利用した再熱除湿運転では、冷媒の適正量が異なる。各運転で同一の冷媒量で運転すると、効率のよい運転を行なうことができない。
【０００７】
【発明が解決しようとする課題】
上記のように、設置場所に汎用性を持たせるために長い延長配管を予め有する場合には、延長配管を設置場所に合わせると共に、これに適正な冷媒量を充填する必要があった。また、予め長い延長配管に追加充填不要な冷媒量を充填した場合には、効率のよい空気調和機の運転を行うことができず、特に再熱除湿運転で十分な再熱量を得ることができないという問題点があった。
また、冷房運転や暖房運転や再熱除湿運転でも冷媒量差が生じ、適正な冷媒量で各運転を行うことができないという問題点があった。
【０００８】
この発明は、上記のような問題点を解消するためになされたもので、余剰液冷媒を貯溜することで、設置場所に合わせた量の冷媒を充填しておく必要がなく、また冷房運転、暖房運転、再熱除湿運転それぞれの運転効率を低下させることなく、且つ再熱除湿運転時に再熱器が液冷媒で満たされることなく、高圧二相冷媒を再熱器に送ることで、大きな再熱量が得られる空気調和機を得ることを目的とする。
【０００９】
【課題を解決するための手段】
この発明に係る空気調和機は、圧縮機、室外熱交換器、流量制御手段、第１室内熱交換器、除湿用流量制御手段、第２室内熱交換器を冷媒配管で順次接続して冷媒を循環させる冷凍サイクルと、冷凍サイクルを循環する冷媒のうち余剰液冷媒を溜める室外熱交換器と流量制御手段の間に配置された液溜め手段と、再熱除湿時に液溜め手段と流量制御手段に対し迂回して循環する冷媒を流す液溜め手段迂回路と、液溜め手段迂回路への分岐部から液溜め手段の出口までのいずれか一部の冷媒を冷却液化して液溜め手段に貯留する冷却手段と、を備えたものである。
【００１０】
この発明に係る空気調和機は、圧縮機、室外熱交換器、流量制御手段、第１室内熱交換器、除湿用流量制御手段、第２室内熱交換器を冷媒配管で順次接続して冷媒を循環させる冷凍サイクルと、冷凍サイクルを循環する冷媒のうち余剰液冷媒を溜める室外熱交換器と流量制御手段の間に配置された液溜め手段と、液溜め手段への冷媒流路に対し液溜め手段と流量制御手段を迂回可能な液溜め手段迂回路と、液溜め手段迂回路への分岐部から液溜め手段の出口までのいずれか一部の冷媒を冷却液化して液溜め手段に貯留する冷却手段と、を備え、室外熱交換器からの冷媒を再熱運転時に液溜め手段を介す流路と液溜め手段迂回路を介す流路を並行して前記第１室内熱交換器へ送るようにしたものである。
【００１２】
この発明に係る空気調和機は、液溜め手段迂回路への分岐部から液溜め手段の出口までの冷媒と圧縮機の吸入側冷媒とを熱交換することで冷媒を冷却液化するようにしたものである。
【００１５】
この発明に係る空気調和機は、第１室内熱交換器の入口と第２室内熱交換器の入口を連通する入口側冷媒配管と、第１室内熱交換器の出口と第２室内熱交換器の出口を連通する出口側冷媒配管と、入口側冷媒配管と出口側冷媒配管のそれぞれを開閉する入口側開閉手段と出口側開閉手段と、を備え、入口側開閉手段と出口側開閉手段を開放して第１室内熱交換器及び第２室内熱交換器を並列接続可能としたものである。
【００１６】
この発明に係る空気調和機は、除湿用流量制御手段と並列に設置されたバイパス流路と、このバイパス流路に設けられた開閉手段と、を備え、開閉手段を開放して第１室内熱交換器及び第２室内熱交換器を直列接続可能としたものである。
【００１７】
この発明に係る空気調和機は、除湿用流量制御手段は、オリフィス部とその上流及び下流の少なくともどちらか一方に多孔質透過材による整流部を有するものである。
【００１９】
この発明に係る空気調和機の運転方法は、所定長さの延長配管を考慮した冷媒量を予め充填した室外ユニットを、現地でその設置場所に応じた長さの延長配管を介して室内ユニットと接続するステップと、を備えたものである。
【００２０】
この発明に係る空気調和機の運転方法は、液溜め手段に余剰液冷媒が溜まったことを判断する際に、室外ユニットの熱交換器出口付近冷媒状態の過冷却度が所定の値以下になったときに液溜め手段に余剰液冷媒が溜まったと判断するものである。
【００２１】
【発明の実施の形態】
実施の形態１．
図１はこの発明の実施の形態１による空気調和機の構成を示す冷媒回路図である。図において、１は室外ユニット、２は室内ユニット、３、４は冷媒配管で、室外ユニット１と室内ユニット２は、冷媒配管である液管３およびガス管４によって接続され、冷媒を循環させて冷凍サイクルを構成している。
室外ユニット１において、５は圧縮機、６は流路切換手段で例えば四方弁、７は室外熱交換器、８は室外熱交換器７と外気との熱交換量を調節する室外送風機、９は例えば電気式膨張弁などの流量制御手段でここでは第１減圧手段、１０は液溜め手段で例えば受液器、１１は受液器１０内の冷媒を冷却する冷却手段である。ここで冷却手段１１は例えば圧縮機５の吸入側冷媒配管である吸入管であり、受液器１０の内部に吸入管１１を挿入することで、受液器１０内の冷媒を冷却している。１２は例えば電気式膨張弁などの流量制御手段でここでは第２減圧手段、１３は受液器１０、第１、第２減圧手段９、１２を迂回する液溜め手段迂回路で、ここではバイパス流路であり、開閉手段である開閉弁１４によって開閉される。
【００２２】
また、室内ユニット２において、１５は第１室内熱交換器、１６は例えばオリフィスを有し再熱除湿時に減圧手段となる除湿用流量制御手段で例えば除湿弁、１７は第２室内熱交換器、１８、１９は開閉手段でここでは開閉弁であり、入口側開閉弁１８は第１、第２室内熱交換器１５、１７の入口を連通する入口側冷媒配管１８ａに設けられこの冷媒配管１８ａを開閉する。同様に、出口側開閉弁１９は第１、第２室内熱交換器１５、１７の出口を連通する出口側冷媒配管１９ａに設けられこの冷媒配管１９ａを開閉する。なお、この空気調和機で使用される冷媒は、例えば低沸点冷媒であるＲ４１０Ａである。
【００２３】
この空気調和機では、冷房運転、暖房運転、再熱除湿運転を行うことができ、以下、第１室内熱交換器１５を凝縮器、第２室内熱交換器１７を蒸発器として機能させる再熱除湿運転の動作について説明する。
第１減圧手段９は所定の開度で開かれ、第２減圧手段１２は開放、開閉弁１４は開放、開閉弁１８および１９は閉止し、四方弁６は実線で示すように接続して運転する。図２は再熱除湿運転を行ったときの冷凍サイクルの動作を示すＰ―ｈ線図で、横軸は比エンタルピーｈ（ｋｃａｌ／ｋｇ）、縦軸は圧力Ｐ（Ｍｐａ）である。
【００２４】
Ａは圧縮機５から吐出された高圧ガスであり、室外熱交換器７で外気と熱交換して凝縮液化する。ここで、室外送風機８は極低速あるいは停止状態であり、外気への放熱を抑制するように制御され、所定の乾き度の高圧二相冷媒状態Ｂとなる。開閉弁１４は開放されており、大部分の冷媒はバイパス流路１３を流れる。また、所定の開度で開かれた第１減圧手段９を通って受液器１０にもわずかに冷媒が流れる。受液器１０に流入した例えば４０℃程度の高圧二相冷媒は、例えば５℃程度の低温である吸入管１１と熱交換して凝縮液化し、飽和液状態Ｃとなって受液器１０内に貯溜される。液冷媒の一部は全開となっている第２減圧手段１２を通ってバイパス流路１３を流れる冷媒と合流し、所定の乾き度の高圧二相状態Ｄとなって室外ユニット１から流出し液管３へと流れる。
【００２５】
室内ユニット２では開閉弁１８、１９は閉止されており、状態Ｄから液管３を通ってわずかに圧力低下した高圧二相冷媒Ｅのすべてが第１室内熱交換器１５へ流入する。第１室内熱交換器１５は再熱器として室内空気に放熱し、冷媒は凝縮して過冷却液状態Ｆとなる。この後除湿弁１６へ流入し、減圧されて低圧二相状態Ｇとなり、第２室内熱交換器１７へ流入する。第２室内熱交換器１７は蒸発器として室内空気から吸熱し、冷媒は蒸発して状態Ｈとなる。この冷媒は、ガス管４を通って室外ユニット１へ戻り、吸入管１１で受液器１０内の冷媒と熱交換を行い、過熱ガス状態Ｉとなって再び圧縮機５へ吸入される。
【００２６】
室内ユニット２に吸込まれた室内空気は、第２室内熱交換器１７で熱交換した後、第１室内熱交換器１５で熱交換する。即ち、吸込まれた室内空気は、第２室内熱交換器１７で冷媒が蒸発することによって冷却除湿される。次に、第１室内熱交換器１５で冷媒が凝縮することによって加熱され、室内に吹き出される。このため、吹き出される空気は吸い込まれた空気とほとんど等しい温度で、除湿のみがなされ、室温が低下しない除湿が可能となる。
【００２７】
以上のように、受液器１０内に流入する二相冷媒を冷却する冷却手段１１を設けることで、室外熱交換器７から流出する冷媒が高圧二相冷媒であっても受液器１０内に余剰冷媒を液冷媒として貯溜することが可能となる。さらに、受液器１０を迂回するバイパス流路１３を設けているので、室外熱交換器７から流出する高圧二相冷媒を再熱器である第１室内熱交換器１５へ送ることが可能となる。この再熱器１５で高圧二相状態である冷媒を凝縮することで、図２のＪに示すように大きな再熱量が得られる。
【００２８】
なお、図１の構成で受液器１０内の冷媒を冷却する冷却手段１１がない場合、受液器１０に余剰冷媒を液冷媒として貯溜するためには、受液器１０の入口における冷媒状態を液冷媒とすることが必要となり、必然的に室外熱交換器７の出口における冷媒状態も液冷媒となる。このため、バイパス流路１３を流れる冷媒も液冷媒となり、液管３を流れる冷媒は液状態となる。従って再熱器１５に流入する冷媒は液冷媒となってしまい、高温液冷媒の顕熱分しか室内空気の加熱量をもたず、再熱量不足となる。
【００２９】
また、図１の構成でバイパス流路１３がない場合には、室外熱交換器出口を二相冷媒とすることは可能であるが、受液器１０に液冷媒が貯溜されると受液器１０の出口における冷媒状態が液冷媒となる。このため、液管３を流れる冷媒は液冷媒となり、上記同様に再熱器１５は過冷却液で満たされ、再熱量不足となる。
【００３０】
上記では冷却手段１１として圧縮機５の吸入側を流れる冷媒を利用した。しかし、冷却手段１１は、バイパス流路１３への分岐点の下流側から受液器１０の出口までの冷媒を冷却する構成のものであれば、室外熱交換器７から流出した高圧二相冷媒を冷却液化して受液器１０に溜めることができ、その構成はどのようなものでもよい。
例えば、図３に示すような受液器１０内の冷媒を冷却する冷却手段１１でもよい。図３は冷却手段１１と受液器１０付近を示す構成図であり、図において、２９は減圧手段である。この減圧手段２９は受液器１０から流出する冷媒液を減圧して低温二相冷媒とする。この低温二相冷媒によって受液器１０内の高温二相冷媒を冷却して液冷媒とし、受液器１０に貯溜させる。受液器１０内の冷媒から吸熱した冷媒は、ガス冷媒となり圧縮機５の吸入側に戻される。
このように、冷凍サイクルを構成する冷媒配管を利用してもよいし、例えば冷却水を流すなど、別の冷却手段を用いてもよい。
また、バイパス流路１３への分岐点の下流側から受液器１０の入口までの冷媒配管と吸入管とを接触させることで、この部分の冷媒配管を流れる冷媒を冷却して液冷媒として受液器１０に流入させるようにしてもよい。バイパス流路１３への分岐点の下流から受液器１０の出口までの冷媒を冷却液化して、受液器１０に液冷媒を溜める構成であればよい。
【００３１】
ただし、図１に示したように吸入側冷媒配管を冷却液化に用いることで、以下のような効果も奏する。圧縮機５の吸入側冷媒は過熱ガスとなるように制御される。ところが第２室内熱交換器１７内の配管のパスバランスが悪いと、あるパスでは著しく過熱度が大きくなり、熱交換器性能を十分に利用することができない。また、吸入側冷媒を二相状態とすると熱交換器性能は有効に利用できるが、圧縮機運転効率の低下および信頼性の低下を招く。そこで、第２室内熱交換器１７から流出する冷媒を受液器１０内の冷媒から吸熱させることで、第２室内熱交換器１７から流出する冷媒が二相状態であったとしても、ガス冷媒として圧縮機５に戻すことができる。このため、第２室内熱交換器１７出口の冷媒を必ずガス冷媒とするのに比べて、制御が容易になる。
【００３２】
再熱除湿運転で受液器１０に溜まる液冷媒の量は、第１減圧手段９又は第２減圧手段１２の開度によって制御可能である。第１減圧手段９の開度によって室外熱交換器７から流出する二相冷媒が受液器１０側に流れる量とバイパス流路１３側に流れる量との割合を制御できる。例えば受液器１０側に流れる量：バイパス流路１３側に流れる量を３：７程度になるように、第１減圧手段９の開度を設定している。また、上記動作の説明では、第２減圧手段１２を全開としているが、第１減圧手段９を全開として第２減圧手段１２の開度を制御することで、受液器１０側に流れる量を制御することもできる。この受液器１０側に流れる冷媒の量によって受液器１０に溜まる液冷媒の量が決まってくる。
【００３３】
次に、冷房運転の動作について説明する。
冷房運転時は、第１減圧手段９、第２減圧手段１２はそれぞれ所定の開度で開かれ、バイパス流路１３に設けられている開閉弁１４は閉止、室内ユニット２の開閉弁１８および１９は開放、四方弁６は実線で示すように接続して運転する。
圧縮機５から吐出されたガス冷媒は四方弁６を通って室外熱交換器７で凝縮液化し、過冷却液冷媒となって第１減圧手段９へ流入する。第１減圧手段９は所定開度に固定か、あるいは室外熱交換器７出口の過冷却度を所定値に調節するように開度が制御され、ここを通過した冷媒は中圧二相状態で受液器１０へ流入する。受液器１０では吸入管１１によって冷媒が凝縮液化し、飽和液冷媒となって貯溜されると共にその一部が第２減圧手段１２へと流れる。第２減圧手段１２は圧縮機５の吸入ガスの過熱度が所定値になるよう開度が調節され、ここを通過する冷媒は減圧膨張して低圧二相状態となって室内ユニット２へと流れる。
【００３４】
室内ユニット２においては開閉弁１８、１９が開放されているため、第１室内熱交換器１５および第２室内熱交換器１７の入口同士および出口同士が連通しており、冷媒はそれぞれの室内熱交換器１５、１７に並列に流れ、室内空気と熱交換して蒸発する。室内ユニット２で蒸発してガス冷媒となりガス管４を通って室外ユニット１へ戻る。そして、吸入管１１で受液器１０内の冷媒と熱交換し、過熱ガスとなって圧縮機５へ吸入される。
【００３５】
このように、この実施の形態では、冷媒回路に封入されている冷媒のうちの余剰冷媒は、冷房運転しながら受液器１０に溜めることができる。
また、冷房運転時には開閉弁１８、１９を開放して第１、第２室内熱交換器１５、１７を並列に接続し、除湿弁１６には冷媒がほとんど通過しないように構成する。このため、それぞれの室内熱交換器１５、１７を冷媒が並行して流れ、除湿弁１６を通過する際の圧力損失が生じることがない。第１、第２室内熱交換器１５、１７がそれぞれ内部で複数の流路に分岐され、それぞれの入口側の分岐部分にディストリビュータ（図示せず）が用いられている場合には、その部分で大きな圧力損失が生じてしまう。例えば第１、第２室内熱交換器１５、１７が直列に接続されている場合にはディストリビュータを二度通過することになり、効率低下を招く。特に第２室内熱交換器１７の入口側でディストリビュータを通過する場合には、冷媒は第１室内熱交換器１５によって蒸発したことでガス冷媒量の多い二相状態であり大幅に効率が低下する。これに対し、この実施の形態のような第１、第２室内熱交換器１５、１７を並列に接続した構成では、冷房運転時にディストリビュータを二度通過することによる効率低下を回避することができる。さらにガス冷媒量の多い二相状態でディストリビュータを通過する構成ではないので、大幅な効率低下を回避できる。
【００３６】
次に、暖房運転の動作について説明する。
第１減圧手段９、第２減圧手段１２はそれぞれ所定の開度で開かれ、開閉弁１４は閉止、開閉弁１８、１９は開放、四方弁６は点線で示すように接続して運転する。
暖房運転では四方弁６を点線のように切換えることにより冷房運転での冷媒循環の方向とは逆に冷媒を循環させる。圧縮機５から吐出されたガス冷媒は四方弁６、ガス管４を通って室内ユニット２へ流れる。室内ユニット２においては開閉弁１８，１９が開放されているため、第１室内熱交換器１５および第２室内熱交換器１７の入口同士および出口同士が連通している。冷媒はそれぞれの室内熱交換器１５、１７に並列に流れ、室内空気と熱交換して凝縮液化する。凝縮液化して過冷却液となった冷媒は、液管３を通って室外ユニット１へ流れて第２減圧手段１２へ流入する。
【００３７】
室外ユニット１の第２減圧手段１２は所定開度に固定か、あるいは室内熱交換器１５、１７の出口の過冷却度を所定値に調節するように開度が制御され、ここを通過した冷媒は中圧二相状態で受液器１０へ流入する。受液器１０では吸入管１１によって冷媒が凝縮液化し、飽和液となって貯溜されると共に、その一部が第１減圧手段９へと流れる。第１減圧手段９は圧縮機５の吸入ガスの過熱度が所定値になるよう開度が調節され、ここを通過する冷媒は減圧膨張して低圧二相状態となって室外熱交換器７へ流入する。室外熱交換器７で外気と熱交換して蒸発したガス冷媒は、吸入管１１で受液器１０内の冷媒と熱交換し、過熱ガスとなって圧縮機５へ吸入される。
【００３８】
このように、暖房運転においても冷媒回路に封入されている冷媒のうちの余剰冷媒は、暖房運転しながら受液器１０に溜まっていく。
また、この運転でも、室内熱交換器１５、１７を並列に冷媒が流れるように構成されており、直列に接続するよりも圧力損失を低くすることができ、運転効率が低下するのを防ぐことができる。
【００３９】
冷凍サイクルでは、通常各運転で必要な冷媒は、暖房運転が一番多く、冷房運転では暖房運転よりも少ない冷媒量であることが好ましく、再熱除湿運転ではさらに両者よりも少ない冷媒量であることが好ましい。この実施の形態では、冷房運転、暖房運転、再熱除湿運転において、封入されている冷媒のうちそれぞれの運転で余剰となる液冷媒を、運転しながら受液器１０に溜め、効率よくそれぞれの運転を行うことができる。このため、各運転において生じる冷媒量の差を、外部から補填したり抜いたりする必要がない。
特に再熱除湿運転で余剰冷媒が多すぎると、再熱器となる第１室内熱交換器１５が液冷媒で満たされてしまい、十分な再熱量が得られない。これに対し、余剰液冷媒を溜める液溜め手段として受液器１０を冷凍サイクル内に設けることで、再熱器が液冷媒で満液になるのを防止でき、再熱量を多く得ることができる。
さらに、数十ｍ程度の延長配管を想定して冷媒量を封入しておいても、余剰液冷媒を受液器１０に溜めることができるので、室内ユニット２と室外ユニット１の距離を容易に可変にでき、両者間の距離において設置条件を制限することなく汎用性の高い空気調和機となる。
受液器１０の容量は、封入冷媒量をほとんど全て収納できる程度の容量、例えば、ここでは数十ｍの延長配管を考慮しており、数リットル程度の容量のものを用いる。延長配管を考慮せず、冷房運転、暖房運転、再熱除湿運転の各運転での冷媒量の差を受液器１０に溜める場合には、数１００ｃｃの容量があれば十分である。
【００４０】
また、受液器１０を高圧側に設けているので、低圧側に設けた構成で生じる冷房運転時及び暖房運転時の運転効率低下を防止できる。即ち、第２室内熱交換器１７の出口と圧縮機５の入口の間の低圧側に液溜め手段として受液器１０を設置した場合には、液冷媒をアキュムレータに溜めかつ冷凍サイクルを効率よく運転することが困難となる。例えば冷房運転時には室内熱交換器１７の出口で二相冷媒となり、またアキュムレータに液冷媒と共に溜まっている圧縮機油を圧縮機５に戻す際に液冷媒も混合してしまい、圧縮機５の吸入側の冷媒が若干湿り状態になってしまう。これは暖房運転時にも同様である。さらに、アキュムレータ内での急拡大急縮小が圧力損失となり、冷媒流量が減少することなどにより運転効率の低下を招くこともある。
この実施の形態では、高圧側に余剰液冷媒を貯溜することで、冷房運転時及び暖房運転時の運転効率を低下させることなく、且つ再熱除湿運転時に高圧二相冷媒を再熱器に送ることが可能な空気調和機を得ることができる。
【００４１】
また、ここで述べた空気調和機は暖房機能も有するものとしたが、暖房機能を必要としない場合には、流路を切換える流路切換手段である四方弁６が必要なくなる。さらに、必ずしも受液器１０の上流側にある第１減圧手段９は必要ではなく、省略しても同様の効果が得られる。第１減圧手段９を設けない場合の冷房運転では、室外送風機８の風量によって、室外熱交換器７の出口の過冷却度を制御すればよい。
【００４２】
実施の形態２．
図４はこの発明の実施の形態２による空気調和機の構成を示す冷媒回路図である。なお、実施の形態１と同一又は相当部分には同一符号を付し、詳細な説明を省略する。実施の形態１では吸入管を受液器１０内に挿入し、受液器１０内の冷媒を冷却液化する冷却手段１１を有する構成としたが、この実施の形態では冷却手段を設けずに余剰液冷媒を受液器１０に溜めることができる。
図における第１、第２減圧手段９、１２は例えば電気式膨張弁であり、共に全閉することが可能な構成のものである。第１、第２減圧手段９、１２と開閉弁１４によって、室外熱交換器７から受液器１０への冷媒流れと液溜め手段迂回路１３への冷媒流れを切換える切換手段を構成している。
【００４３】
以下、再熱除湿運転の動作について説明する。
空気調和機の電源がオンとなった後にすぐに再熱除湿運転が要求された場合、再熱除湿運転に入る前にまず冷房運転を行なう。この冷房運転時の動作は前述の実施の形態1と全く同様であり、室外ユニット１の開閉弁１４は閉止、第１減圧手段９、第２減圧手段１２はそれぞれ所定の開度で開かれ、室内ユニット２の２つの開閉弁１８，１９は開放する。この状態で、実施の形態１に記載した冷房運転と同様の冷房運転をしばらく行ったのち、再熱除湿運転を行う。
例えば室外熱交換器７の出口における冷媒の状態を監視し、その過冷却度が５℃以下、例えば２℃程度の過冷却度になったら、受液器１０には所定量の余剰液冷媒が貯溜され、冷凍サイクル内を循環する冷媒量が再熱除湿運転に適正量になったと判断できる。そこで、再熱除湿運転へ切換える。ここで、再熱除湿運転での冷凍サイクルの循環冷媒量は、冷房運転よりも少ない方が好ましい。通常の冷房運転では、室外熱交換器７の出口における冷媒の過冷却度が５℃程度で運転しており、この過冷却度以下に制御することで、冷房運転に適正な量よりも多くの液冷媒を受液器１０に貯溜できる。
【００４４】
再熱除湿運転へ切換える際、第１減圧手段９および第２減圧手段１２を完全に閉止し、冷凍サイクルでの余剰液冷媒を受液器１０内に隔離する。冷凍サイクル内には封入冷媒量より少ない量の冷媒が循環することになる。この状態で、再熱除湿運転の回路を構成するように、開閉弁１４を開放し、室内ユニット２内の開閉弁１８，１９を閉止する。冷房運転時に室外熱交換器７に存在していた過冷却液は再熱器１５内に移動するが、余剰液冷媒は受液器１０内に隔離されているため、再熱器１５が満液になることはない。再熱除湿運転では、室外送風機８の風量を極低速か停止状態になるように調節し、室外熱交換器７の出口における冷媒状態が高圧二相状態で流出するように運転する。このため、再熱器１５の入口における冷媒状態は高圧二相状態のまま運転可能となり、再熱量を大きくすることができる。
【００４５】
このように、余剰冷媒を受液器１０内に隔離し、冷凍サイクル中に再熱除湿運転に適正量の冷媒を残存させることによって、室外熱交換器７の出口Ｂ、Ｄおよび再熱器１５の入口Ｅにおける冷媒の状態を高圧二相状態にすることが可能となる。このため、封入冷媒量が多くても、高圧二相状態のまま冷媒を室内熱交換器１５に送ることができ、再熱量を多くとることができる。
【００４６】
なお、上記では、冷房運転で受液器１０に余剰液冷媒が溜まったことを、室外熱交換器７の出口での冷媒状態で判断したが、これに限るものではない。例えばその空気調和機で冷房運転を行った時に予め余剰液冷媒が溜まる時間を求め、この時間だけ冷房運転を行うようにしてもよい。また、受液器１０の液面を計測する液面センサを設け、この液面センサの検知によって冷房運転から再熱除湿運転に切換えるようにしてもよい。
【００４７】
また、上記では第１、第２減圧手段９、１２と開閉弁１４によって、室外熱交換器７から受液器１０への冷媒流れと液溜め手段迂回路１３への冷媒流れを切換える切換手段を構成している。切換手段はこれに限るものではなく、例えば、液溜め手段迂回路１３の上流及び下流の分岐部および合流部に、三方弁を配設しても、流路を切換えることができる。
【００４８】
また、この構成で、実施の形態１のように受液器１０内の冷媒を冷却する冷却手段を備えてもよい。受液器１０内の冷媒を冷却することにより、再熱除湿運転の前に行う冷房運転において、受液器１０に二相冷媒が流入した場合にも液冷媒とすることができ、受液器１０内に余剰液冷媒を速く溜めることができる。この冷却手段は、図１や図３に示したように、冷凍サイクルを構成する冷媒配管を利用してもよいし、例えば冷却水を流すなど、別の冷却手段を用いてもよい。
また、実施の形態１でも述べたが、バイパス流路１３への分岐部から受液器１０の入口までの冷媒を冷却するような冷却手段を設けてもよい。
この実施の形態では、空気調和機の電源オン後すぐに再熱除湿運転が要求された場合に、再熱除湿運転を行なう前に冷房運転を行なうものであり、冷房運転を行なう時間を短くできることは、利用者の要求を早く行なうことができるという効果がある。
【００４９】
空気調和機の電源オン後、冷房運転または暖房運転を行った後に再熱除湿運転が要求された場合には、受液器１０に余剰冷媒が溜まった状態であるので、予め冷房運転を行う必要はない。この場合には、すぐに第１、第２減圧手段９、１２を完全に閉止して余剰冷媒を冷凍サイクルから隔離し、開閉弁１４を開放、開閉弁１８、１９を閉止して、再熱除湿運転を行なえばよい。
【００５０】
また、再熱除湿運転を行う前に受液器１０に余剰液冷媒を溜めるために冷房運転を行うようにしたが、梅雨時などの気温の低い日に冷房運転を行ないたくない時には、まず暖房運転を行うようにしてもよい。実施の形態１で説明したように、暖房運転によっても受液器１０に余剰液冷媒を溜めることができる。そして余剰液冷媒が受液器１０にある程度溜まり、再熱除湿運転に適正量の冷媒が冷凍サイクルを循環するようになった時点で再熱除湿運転に切換えればよい。ただし、ここでは再熱除湿運転での冷媒の循環を冷房運転と同様にしており、暖房運転後に再熱除湿運転を行なうよりも、冷房運転後に再熱除湿運転を行なう方がスムーズに冷媒回路を切換えることができる。
【００５１】
図４の構成において、冷房運転及び暖房運転は、実施の形態１と同様に行なわれ、構成、動作、作用効果は実施の形態１と同様である。ここでは詳細な説明は省略する。
【００５２】
さらに、実施の形態１と同様、以下のような構成、動作、及び作用効果を奏する。即ち、冷暖房運転時には第１、第２室内熱交換器１５、１７を並列に接続し、除湿弁１６には冷媒が通過しないように構成する。これにより、それぞれの室内熱交換器１５、１７に冷媒を並行して流すことで、圧力損失の増加を防止でき、圧力損失の増大による大幅な効率低下を回避できる。
【００５３】
実施の形態３．
図５はこの発明の実施の形態３による空気調和機の構成を示す冷媒回路図である。なお、実施の形態１、２と同一又は相当部分には同一符号を付し、詳細な説明を省略する。
図において、３０、３１は開閉手段、例えば開閉弁である。３０ａはガス冷媒配管で、受液器１０の上部から開閉弁３０を介して第２減圧手段１２の下流に受液器１０内のガスを流す流路である。３１ａはバイパス流路で、除湿弁１６と並列に接続されている。この実施の形態では、室外熱交換器７の出口Ｂから受液器１０の出口Ｃまでの間に実施の形態１に示した冷却手段を設けていない。開閉弁３０の開閉によってガス冷媒配管３０ａの開閉が行われる。また、室内ユニット２においてはバイパス流路３１ａに開閉弁３１が設けられ、開閉弁３１を開閉することで、バイパス流路３１ａの開閉が行われる。
【００５４】
この実施の形態での再熱除湿運転の動作について説明する。この実施の形態においては、再熱除湿運転時に第１、第２減圧手段９、１２は全開として圧力低下のないように制御すると共に、開閉弁３０を開放、開閉弁３１を閉止する。四方弁６は実線で示す様に接続する。
圧縮機５から吐出された高温高圧のガス冷媒は、室外熱交換器７で外気と熱交換して凝縮液化する。ここで、室外送風機８は極低速あるいは停止状態であり、外気への放熱を抑制するよう制御され、冷媒は所定の乾き度の高圧二相冷媒状態となる。第１減圧手段９は開放されており、冷媒は高圧二相冷媒状態のまま受液器１０に流入する。
【００５５】
高圧二相冷媒状態で受液器１０に流入した冷媒は、開閉弁３０を介したガス冷媒配管３０ａがない場合には、そのまま高圧二相冷媒で減圧手段１２を通って流出するので、受液器１０には余剰液冷媒が溜まらない。この実施の形態では受液器１０の上部からガス冷媒配管３０ａを設けている。このため、流入した高圧二相冷媒は分離してガス冷媒が受液器１０の上方に溜まると共に、液冷媒は飽和液冷媒となって受液器１０の下方に溜まる。受液器１０の上部のガス冷媒は開閉弁３０を介してガス冷媒配管３０ａを流れる。一方、受液器１０の下方から飽和液冷媒の一部が第２減圧手段１２を通って流出し、ガス冷媒と合流する。そして、高圧二相冷媒となって液管３を介して室内ユニット２に流れる。そして再熱器として機能する第１室内熱交換器１５へと送られ、ここで高圧二相冷媒は凝縮液化し、過冷却液冷媒となって除湿弁１６を通過する。除湿弁１６で減圧されて低圧二相冷媒となり、第２室内熱交換器１７において蒸発し、ガス管４を通って再び圧縮機５に吸入される。
【００５６】
この構成では、実施の形態１のように、室外熱交換器７の出口Ｂから受液器の出口Ｃまでの間に冷却手段を設けず、かつ、受液器１０及び減圧手段９、１２を迂回する液溜め迂回路を設けずとも、受液器１０内のガス冷媒を受液器１０の出口の液冷媒と合流させることにより、再熱器１５の入口Ｅにおける冷媒を高圧二相冷媒とすることが可能となる。この開閉弁３０は、電磁弁等による開閉動作の他、可変絞り手段として、ガス側の流量を調節できるようにしてもよい。
【００５７】
ここで受液器１０に溜まる冷媒液の量は、室外熱交換器７での凝縮の程度によって決まる。即ち、室外送風機８の風量によって変化する。そこで第２室内熱交換器１７の出口での乾き度を監視し、所定の乾き度になるように、室外送風機８の風量を制御すればよい。
【００５８】
この実施の形態において、実施の形態１と同様に受液器１０内の冷媒を冷却する冷却手段を設けてもよい。受液器１０内の冷媒を冷却することにより、受液器１０内に余剰液冷媒を速く確実に溜めることができる。この冷却手段は、図１や図３に示したように、冷凍サイクルを構成する冷媒配管を利用してもよいし、例えば冷却水を流すなど、別の冷却手段を用いてもよい。ただし、受液器１０に流入する冷媒は高圧二相状態とする。
【００５９】
以上のように、受液器１０の上方と第２減圧手段１２の下流側を接続するガス冷媒配管３０ａを備え、室外熱交換器７から流出する高圧二相冷媒を流入して受液器１０に液冷媒を溜めると共に、ガス冷媒配管３０ａから流出するガス冷媒を受液器１０の下方から流出する液冷媒と合流して高圧二相状態で第１室内熱交換器１５に送るようにしたことで、室外熱交換器７から流出する冷媒が高圧二相冷媒であっても受液器１０内に余剰冷媒を液冷媒として貯溜すると共に、高圧二相冷媒を再熱器である第１室内熱交換器１５へ送ることが可能となる。この再熱器１５で高圧二相状態である冷媒を凝縮することで、大きな再熱量が得られる。
【００６０】
次に、冷房運転時の動作について説明する。
冷房運転時には、室外ユニット１の開閉弁３０を閉止し、室内ユニット２に設けられている開閉弁３１を開放する。この冷媒回路において、圧縮機５から吐出されたガス冷媒は四方弁６を通って室外熱交換器７で凝縮液化し、過冷却液となって第１減圧手段９へ流入する。減圧手段９は所定開度に固定か、あるいは室外熱交換器７出口の過冷却度を所定値に調節するように開度が制御され、ここを通過した冷媒は飽和液状態で受液器１０へ流入する。ここで、余剰液冷媒は受液器１０内に貯溜されると共にその一部が第２減圧手段１２へと流れる。第２減圧手段１２は圧縮機５の吸入ガスの過熱度が所定値、例えば１０℃程度の過熱度になるように開度が調節され、ここを通過する冷媒は低圧二相状態となって室内ユニット２へと流れる。
【００６１】
室内ユニット２においては第１室内熱交換器１５で冷媒は蒸発し、開放されている開閉弁３１および除湿弁１６を通過して第２室内熱交換器１７で同様に蒸発する。室内ユニット２で蒸発したガス冷媒はガス管４を通って室外ユニット１へ戻り、圧縮機５へ吸入される。このように、冷房運転時には除湿弁１６と共に開閉弁３１を通過するので、第１、第２室内熱交換器１５、１７の双方をほとんど同一の蒸発温度で使用できる。
暖房運転は、冷房運転で四方弁６を点線で示すように接続して冷媒を冷房運転とは逆に循環させ、室内ユニット２の熱交換器１５、１７を凝縮器、室外ユニット１の熱交換器７を蒸発器として動作させる。
【００６２】
室内ユニット２の第１室内熱交換器１５と第２室内熱交換器１７は、冷房運転または暖房運転で第１、第２室内熱交換器に直列に冷媒を流している。実施の形態１、２で示したように第１、第２室内熱交換器に並列に冷媒を流す構成に比べ、運転効率は少し低減するが、開閉手段の数を減らすことで安価な空気調和機を得ることができるという効果を奏する。また、実施の形態１、２と同様、冷房運転及び暖房運転では並列に接続してもよい。第１、第２室内熱交換器１５、１７に冷媒を並列に流すことで、第１、第２室内熱交換器１５、１７を直列に通過する時よりも圧力損失を減らすことができ、運転効率の低下を防止できる。
また、実施の形態１、２において、実施の形態３で示したような開閉手段３１を設けて、冷媒を第１、第２室内熱交換器１５、１７を直列に通過させてもよい。この場合、運転効率は少し低減するが、開閉手段の数を減らすことで安価な空気調和機を得ることができるという効果を奏する。
【００６３】
この実施の形態では、冷媒回路に封入されている冷媒のうちの余剰冷媒は、冷房運転又は暖房運転しながら受液器１０に溜めることができる。このため、室内ユニット２と室外ユニット１の距離を容易に可変にでき、両者間の距離において設置条件を制限することなく汎用性の高い空気調和機となる。
また、実施の形態１と同様、受液器１０を高圧側に設けているので、低圧側に設けた構成で生じる冷房運転時及び暖房運転時の運転効率低下を防止できる。即ち、高圧側に余剰液冷媒を貯溜することで、冷房運転時及び暖房運転時の運転効率を低下させることなく、且つ再熱除湿運転時に高圧二相冷媒を再熱器に送ることが可能な空気調和機を得ることができる。
【００６４】
また、ここで述べた空気調和機は暖房機能も有するものとしたが、暖房機能を必要としない場合には、流路を切換える流路切換手段である四方弁６が必要なくなる。また、さらに、冷房運転での冷媒循環で受液器１０の上流側にある第１減圧手段９は必ずしも必要ではなく、省略しても同様の効果が得られる。
【００６５】
実施の形態１と実施の形態３の構成は、電源オン後、すぐに再熱除湿運転を行なっても、運転しながら余剰液冷媒を受液器１０に溜めることができるが、実施の形態２と同様にまず暖房運転又は冷房運転を行なうステップがあってもよい。この冷房運転または暖房運転である程度余剰液冷媒を受液器１０に溜めた後に、開閉弁や流量制御手段を切換えて再熱除湿運転を行なうように構成してもよい。このように再熱除湿運転を行なう前にある程度余剰冷媒液を受液器１０に溜めておけば、冷凍サイクル内を循環する冷媒を速く適正量にすることができ、効率のよい運転を行なうことができる。
【００６６】
実施の形態４．
実施の形態１〜実施の形態３のそれぞれは、受液器１０を高圧側に設けた構成である。余剰液冷媒を貯溜する液溜め手段を有し、再熱除湿運転を行なう空気調和機においては、冷媒回路の高圧側に液溜め手段を設けた場合、再熱器１５に高圧で且つ高乾き度の二相冷媒を送ることが困難であった。これに対し、冷媒回路の低圧側に液溜め手段を設けた場合は、冷房運転及び暖房運転の際に受液器１０が圧縮機５の吸入側を湿り状態となるためある程度の運転効率の低下はあるが、受液器１０に余剰液冷媒を溜め、かつ室外熱交換器７の出口を高圧二相冷媒とすることは容易となる。
ここで、低圧側に余剰液冷媒を貯溜する液溜め手段を設けた空気調和機の実施の形態について説明する。図６はこの発明の実施の形態４による空気調和機の構成を示す冷媒回路図である。なお、実施の形態１と同一又は相当部分には同一符号を付し、詳細な説明を省略する。
この実施の形態は、第２室内熱交換器１７と圧縮機５の間の低圧側に液溜め手段である受液器１０を設ける。また、室外熱交換器７と第１室内熱交換器１５の間に流量制御を行う流量制御手段として減圧手段１２を設けている。
【００６７】
この実施の形態での再熱除湿運転の動作について説明する。
この実施の形態においては、再熱除湿運転時に減圧手段１２は開放して圧力低下のないように制御すると共に、開閉弁１８、１９を閉止する。四方弁６は実線で示す様に接続する。
圧縮機５から吐出された高温高圧のガス冷媒は、室外熱交換器７で外気と熱交換して凝縮液化する。ここで、室外送風機８は極低速あるいは停止状態であり、外気への放熱を抑制するよう制御され、冷媒は所定の乾き度の高圧二相冷媒状態となる。減圧手段１２は開放されており、冷媒は高圧二相冷媒状態のまま液管３を介して室内ユニット２に流れる。そして再熱器として機能する第１室内熱交換器１５へと送られ、ここで高圧二相冷媒は凝縮液化し、過冷却液冷媒となって除湿弁１６を通過する。除湿弁１６で減圧されて低圧二相冷媒となり、第２室内熱交換器１７において蒸発し、低圧二相冷媒となる。そしてガス管４を通って受液器１０に流入し、受液器１０の上部からガス冷媒が圧縮機５に吸入される。受液器１０に流入した液冷媒は、余剰液冷媒として受液器１０に溜まっていく。
【００６８】
冷房運転では、減圧手段１２は所定の開度に制御し、開閉弁１８、１９を開放する。四方弁６は実線で示すように接続する。
圧縮機５から吐出された高温高圧のガス冷媒は、室外熱交換器７で外気と熱交換して凝縮液化し、過冷却状態で室外熱交換器７から流出する。減圧手段１２は第２室内熱交換器１７の出口の冷媒状態が所定の濡れ度になるように制御され、冷媒は減圧膨張して低圧二相冷媒状態で液管３を通り、室内ユニット２に流れる。そして蒸発器として機能する第１、第２室内熱交換器１５、１７に並行して送られ、ここで室内空気と熱交換して蒸発し、低圧二相冷媒となる。そしてガス管４を通って受液器１０に流入し、受液器１０の上部からガス冷媒が圧縮機５に吸入される。受液器１０に流入した液冷媒は、余剰液冷媒として受液器１０に溜まっていく。
【００６９】
また、暖房運転では、減圧手段１２は所定の開度に制御し、開閉弁１８、１９を開放する。四方弁６は点線で示すように接続する。
圧縮機５から吐出された高温高圧のガス冷媒は、凝縮器として機能する第１、第２室内熱交換器１５、１７を並行して流れ、ここで室内空気と熱交換して凝縮液化し、過冷却状態で第１、第２室内熱交換器１５、１７から流出する。そして液管３を介して室外ユニット１に流れる。減圧手段１２は室外熱交換器７の出口の冷媒状態が所定の濡れ度になるように制御され、冷媒は低圧二相冷媒状態で室外熱交換器７に流入する。そして蒸発器として機能する室外熱交換器７で外気と熱交換して蒸発し、低圧二相冷媒となる。この後受液器１０に流入し、受液器１０の上部からガス冷媒が圧縮機５に吸入される。受液器１０に流入した液冷媒は、余剰液冷媒として受液器１０に溜まっていく。
【００７０】
このように、受液器１０を冷凍サイクルの低圧側に設けた場合にも余剰液冷媒を溜めることができ、再熱器１５が満液になるのを防いで再熱量を多くとることができる。特に、実施の形態１〜実施の形態３では、高圧側に設けた受液器１０に液冷媒を溜めると共に再熱器１５に冷媒を高圧二相状態で送るために、冷却手段１１や液溜め迂回路１３やガス冷媒配管３０ａなどを設けた。これに対し、この実施の形態による構成では、冷凍サイクルの低圧側に受液器１０を設けるだけで再熱量の多い空気調和機が得られる。
【００７１】
以上、実施の形態１〜実施の形態４で示したように、液溜め手段である受液器１０を再熱機能を有する空気調和機の冷凍サイクルに設けることで、余剰液冷媒を貯溜し、設置場所に応じた量の冷媒を充填しておく必要がなく、また循環冷媒量が多すぎて冷房運転、暖房運転、再熱除湿運転それぞれの運転効率が低下するのを防ぎ、且つ再熱除湿運転時に再熱器が液冷媒で満たされることなく、高圧二相冷媒を再熱器に送ることで、大きな再熱量が得られる。
【００７２】
ここで、実施の形態１〜実施の形態４のそれぞれの空気調和機を設置する場合について説明する。例えば工場内で室外ユニット１と室内ユニット２をそれぞれ組み立てる。そして室外ユニット１に所定長さ、例えば最長３０ｍ程度の延長配管を考慮した冷媒量を予め充填する。この室外ユニット１および室内ユニット２は標準仕様であり、設置場所がどのような状況であっても、そのまま設置する。ところが室外ユニット１と室内ユニット２の距離は、設置場所に応じて様々である。このため、現地で設置場所に応じた長さの延長配管を介して室外ユニット１と室内ユニット２とを接続する。延長配管は各実施の形態で冷媒配管３、４に相当する。この後、冷房運転または暖房運転を行なう。このように、液溜め手段１０に余剰液冷媒を溜めて運転することで、冷媒を補充したり抜いたりする作業を必要とせず、冷房運転または暖房運転または再熱除湿運転で適正量の冷媒を循環させ、効率のよい運転を行なうことができる。
【００７３】
実施の形態５．
以下、実施の形態１〜実施の形態４のそれぞれにおいて、室内ユニット２内の第１、第２室内熱交換器１５、１７の間に設置されている除湿用流量制御手段１６に関して説明する。この除湿用流量制御手段、ここでは除湿弁１６は、固定の開度の減圧手段で構成する場合には、キャピラリーチューブや、オリフィス部を有するものなどを用いることができる。また、開度が可変である減圧手段で構成する場合には、電気式膨張弁などを用いることができる。開度を全開にできる電気式膨張弁を用いた場合には、図１、図４、図６に示すような冷媒配管１８ａ、１９ａや、図５に示すようなバイパス流路３１ａは必要がなくなる。
【００７４】
ここでは、冷媒流動音を低減できる減圧手段である除湿弁１６について説明する。図７は実施の形態５に係る除湿弁１６を示す断面構成図である。図７を参照して室内ユニット２に配設される除湿弁１６の構造について説明する。実施の形態１〜実施の形態４で記載した様に、除湿弁１６は再熱除湿運転の時に第１室内熱交換器１５から流出する冷媒を減圧膨張して第２室内熱交換器１７に流入させる機能を有する。冷房運転又は暖房運転では冷媒のほとんどは除湿弁１６を迂回して流れるので、第１、第２室内熱交換器１５、１７の間は開放されて冷媒は減圧されない。再熱除湿運転時は図７の矢印方向に冷媒が流れるものとする。
図において、２１はオリフィス部であり、冷媒が細孔を通過して減圧される部分である。２２はオリフィス部２１の上流側に設けた入口側多孔質透過材、２３はオリフィス部２１の下流側に設けた出口側多孔質透過材、２４、２５、２６、２７はそれぞれ多孔質透過材２２、２３の前後の空間である。
【００７５】
再熱除湿運転で再熱器として機能する第１室内熱交換器１５を通過し、凝縮液化した高圧冷媒は空間２４へ流入する。ここで、入口側多孔質透過材２２に衝突し、均質な流れとなって整流されて空間２５に到達する。次にオリフィス部２１によって減圧され、低圧二相冷媒となって空間２６に噴出される。この低圧二相冷媒は出口側多孔質透過材２３に衝突し、均質な流れとなって整流されて空間２７に到達する。
【００７６】
例えば除湿弁１６がオリフィス部２１のみで構成される減圧手段を気液二相冷媒が通過する際には、大きな冷媒流動音が発生する。特に気液二相冷媒の流動様式がスラグ流となる場合に、大きな冷媒流動音が発生することが知られている。この冷媒流動音の発生要因としては、除湿弁１６内のオリフィス部２１などの小孔をスラグ流が通過する際に、小孔よりも大きな冷媒蒸気スラグあるいは冷媒気泡が破壊される。この冷媒蒸気スラグあるいは冷媒気泡の崩壊により振動が発生することや、小孔を蒸気冷媒と液冷媒が交互に通過するため、この小孔を冷媒が通過する際に発生する圧力損失が大きく変動することが考えられる。また、オリフィス部２１の出口では、速度が大きく、また乱れも大きな気液二相噴流が形成され、この気液二相噴流による圧力変動も冷媒流動音の発生要因である。そこで、オリフィス部２１の上流側に配設した多孔質透過材２２によって、気液二相冷媒を整流して液体と気体を均質気液二相流（蒸気冷媒と液冷媒とがよく混合された状態）とすることで、除湿弁１６内のオリフィス部２１近傍で発生する冷媒流動音を低下させることができる。
【００７７】
また、オリフィス部２１を通過した速度の速い冷媒が除湿弁１６の内壁に直接衝突すると、やはり冷媒流動音が大きくなる。これに対してオリフィス部２１の下流側に多孔質透過材２３を設けることで、冷媒流れを整流して均質化し、冷媒流動音を低減する。
【００７８】
このように、オリフィス部２１の前後に発泡金属などの多孔質透過材２２、２３を配設することで、減圧される前の空間２５および減圧された後の空間２７では均質な流れを形成する。このため、気液二相流に起因する不連続音や圧力脈動が低減される。
ここで、多孔質透過材２２、２３は、例えば通気孔（流体が透過することのできる多孔質体内部の気孔）の径を１００μｍ以上１０００μｍ以下とし、厚さを１ｍｍから１０ｍｍとし、例えばＮｉまたはＮｉ−Ｃｒまたはステンレスからなる発泡金属を使用している。冷媒流動音を下げる効果から、通気孔の径を１０００μｍ以下とするのが好ましい。また、通常冷凍サイクルには循環する冷媒に混入して循環する塵などを取り除くためにストレーナが配設されている。このストレーナの目の荒さと同程度以上にすることで、多孔質透過材２２、２３に塵などが詰るのを防ぐことができるので、通気孔の径を１００μｍ以上とするのが好ましい。
なお、多孔質透過材は発泡金属に限るものではなく、金属の粉末を焼結した焼結金属、またはセラミックスの多孔質透過材、または金網や、金網を数枚重ねたもの、また金網を数枚重ねて焼結した焼結金網や積層金網でも同様の効果を得ることができる。
【００７９】
また、図７で示した減圧手段１６は、オリフィス部２１の上流側及び下流側の両方に多孔質透過材２２、２３を設けた構成としたが、上流側及び下流側の一方に設けた構成でもよい。少なくともどちらか一方に多孔質透過材を設ければ、オリフィス部のみの構成に比べ、冷媒を整流均質化して冷媒流動音を低減できる。
【００８０】
また、実施の形態１〜実施の形態５のそれぞれにおいて、冷凍サイクルの冷媒としてＨＦＣ系冷媒のＲ４１０Ａを用いた。この冷媒はオゾン層を破壊しない地球環境保全に適した冷媒であると共に、低沸点冷媒であり、従来冷媒として用いられてきたＲ２２に比べて、冷媒蒸気密度が大きく冷媒の流速が遅くなるため圧力損失が小さく、複数用いられている流量制御手段に口径の小さい安価な電磁弁を使用しても圧力低下が小さく、低コスト化を図ることができる。
【００８１】
ただし、冷媒としてＲ４１０Ａに限るものではなく、ＨＦＣ系冷媒であるＲ４０７ＣやＲ４０４Ａ、Ｒ５０７Ａであってもよい。また、地球温暖化防止の観点から、地球温暖化係数の小さなＨＦＣ系冷媒であるＲ３２単独、Ｒ１５２ａ単独、またはＲ３２／Ｒ１３４ａなどの混合冷媒であってもよい。
また、プロパンやブタン、イソブタンなどのＨＣ系冷媒やアンモニア、二酸化炭素、エーテルなどの自然系冷媒およびそれらの混合冷媒であってもよい。
【００８２】
【発明の効果】
以上説明したように、この発明に係る空気調和機は、圧縮機、室外熱交換器、流量制御手段、第１室内熱交換器、除湿用流量制御手段、第２室内熱交換器を冷媒配管で順次接続して冷媒を循環させる冷凍サイクルと、冷凍サイクルを循環する冷媒のうち余剰液冷媒を溜める室外熱交換器と流量制御手段の間に配置された液溜め手段と、再熱除湿時に液溜め手段と流量制御手段に対し迂回して循環する冷媒を流す液溜め手段迂回路と、液溜め手段迂回路への分岐部から液溜め手段の出口までのいずれか一部の冷媒を冷却液化して液溜め手段に貯留する冷却手段と、を備えたので、冷房運転又は暖房運転又は再熱除湿運転のそれぞれで適正量の冷媒を循環させることで効率良く運転でき、余剰液冷媒を液溜め手段に溜めるとともに、第１室内熱交換器が液冷媒で満液になるのを防ぎ、再熱量の多い再熱除湿運転を行うことが出来る。
【００８３】
この発明に係る空気調和機は、圧縮機、室外熱交換器、流量制御手段、第１室内熱交換器、除湿用流量制御手段、第２室内熱交換器を冷媒配管で順次接続して冷媒を循環させる冷凍サイクルと、冷凍サイクルを循環する冷媒のうち余剰液冷媒を溜める室外熱交換器と流量制御手段の間に配置された液溜め手段と、液溜め手段への冷媒流路に対し液溜め手段と流量制御手段を迂回可能な液溜め手段迂回路と、液溜め手段迂回路への分岐部から液溜め手段の出口までのいずれか一部の冷媒を冷却液化して液溜め手段に貯留する冷却手段と、を備え、室外熱交換器からの冷媒を再熱運転時に液溜め手段を介す流路と液溜め手段迂回路を介す流路を並行してして前記第１室内熱交換器へ送るようにしたので、冷房運転又は暖房運転又は再熱除湿運転のそれぞれで適正量の冷媒を循環させることで効率良く運転でき、余剰液冷媒を液溜め手段に溜めるとともに、第１室内熱交換器が液冷媒で満液になるのを防ぎ、再熱量の多い再熱除湿運転を行うことが出来る。
【００８５】
この発明に係る空気調和機は、液溜め手段迂回路への分岐部から液溜め手段の出口までの冷媒と圧縮機の吸入側冷媒とを熱交換することで冷媒を冷却液化するようにしたので、冷房運転又は暖房運転で運転効率が低下するのを防止でき、再熱量の多い再熱除湿運転を行うことが出来、更に圧縮機吸入側冷媒状態を確実にガス冷媒にすることが出来る。
【００８８】
この発明に係る空気調和機は、第１室内熱交換器の入口と第２室内熱交換器の入口を連通する入口側冷媒配管と、第１室内熱交換器の出口と第２室内熱交換器の出口を連通する出口側冷媒配管と、入口側冷媒配管と出口側冷媒配管のそれぞれを開閉する入口側開閉手段と出口側開閉手段と、を備え、入口側開閉手段と出口側開閉手段を開放して第１室内熱交換器及び第２室内熱交換器を並列接続可能としたので、冷房運転又は暖房運転で直列に接続した構成よりも圧力損室を低減でき、高効率冷房運転又は暖房運転が可能となる。
【００８９】
この発明に係る空気調和機は、除湿用流量制御手段と並列に設置されたバイパス流路と、このバイパス流路に設けられた開閉手段と、を備え、開閉手段を開放して第１室内熱交換器及び第２室内熱交換器を直列接続可能としたので、冷房運転又は暖房運転で並列に接続した構成よりも切換え動作が簡単で、開閉手段の個数を減らして安価に構成できる。
【００９０】
この発明に係る空気調和機は、除湿用流量制御手段は、オリフィス部とその上流及び下流の少なくともどちらか一方に多孔質透過材による整流部を有するので、室内ユニットにおける除湿用流量制御手段内の気液二相流動による騒音を低減できる。
【００９２】
この発明に係る空気調和機の運転方法は、所定長さの延長配管を考慮した冷媒量を予め充填した室外ユニットを、現地でその設置場所に応じた長さの延長配管を介して室内ユニットと接続するステップと、を備えたので、設置時の作業が比較的簡単な空気調和機を構成でき、余剰液冷媒を液溜め手段に溜めるとともに、再熱量の多い再熱除湿運転を行うことが出来る。
【００９３】
この発明に係る空気調和機の運転方法は、液溜め手段に余剰液冷媒が溜まったことを判断する際に、室外ユニットの熱交換器出口付近冷媒状態の過冷却度が所定の値以下になったときに液溜め手段に余剰液冷媒が溜まったと判断するので、余剰液冷媒を液溜め手段に確実に溜めるとともに、再熱量の多い再熱除湿運転を行うことが出来る。
【図面の簡単な説明】
【図１】 この発明の実施の形態１による空気調和機の構成を示す冷媒回路図である。
【図２】 実施の形態１に係る冷凍サイクル動作を示Ｐ−ｈ線図である。
【図３】 実施の形態１に係る別の冷却手段を示す構成図である。
【図４】 この発明の実施の形態２による空気調和機の構成を示す冷媒回路図である。
【図５】 この発明の実施の形態３による空気調和機の構成を示す冷媒回路図である。
【図６】 この発明の実施の形態４による空気調和機の構成を示す冷媒回路図である。
【図７】 この発明の実施の形態５に係る除湿用流量制御手段を示す断面構成図である。
【図８】 従来の空気調和機を示す冷媒回路図である。
【符号の説明】
１ 室外ユニット、２ 室内ユニット、３、４ 冷媒配管、５ 圧縮機、６ 流路切換手段、７ 室外熱交換器、８ 室外送風機、９ 流量制御手段、１０ 液溜め手段、１１ 冷却手段、１２ 流量制御手段、１３ 液溜め手段迂回路、１４ 開閉手段、１５ 第１室内熱交換器、１６ 除湿用流量制御手段、１７ 第２室内熱交換器、１８ 入口側開閉手段、１８ａ 入口側冷媒配管、１９ 出口側開閉手段、１９ａ 出口側冷媒配管、２１ オリフィス部、２２、２３ 多孔質透過材、２４〜２７ 空間、３０ 開閉手段、３０ａ ガス冷媒配管、３１開閉手段、３１ａ バイパス流路。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner having a reheat dehumidification function and an operating method of the air conditioner.
[0002]
[Prior art]
FIG. 8 is a refrigerant circuit diagram showing a main flow of refrigerant in an air conditioner having a reheat dehumidification function described in Japanese Patent No. 3181418. In the figure, 1 is an outdoor unit, 2 is an indoor unit, 3, 4 is a refrigerant pipe, 5 is a compressor, 6 is a four-way valve, 7 is an outdoor heat exchanger, 8 is an outdoor fan, 12 is a decompression means, and 15 is a first unit. 1 is an indoor heat exchanger, 16 is a pressure reducing means, 17 is a second indoor heat exchanger, and 31 is an on-off valve provided in parallel with the pressure reducing means 16.
[0003]
Hereinafter, the operation during the reheat dehumidification operation will be described. The four-way valve 6 is connected as shown by the solid line in FIG. 8, and the on-off valve 31 in the indoor unit 2 is closed. The first and second indoor heat exchangers 15 and 17 operate as a reheater 15 and an evaporator 17.
The high-temperature and high-pressure gas refrigerant compressed by the compressor 5 enters the outdoor heat exchanger 7 through the four-way valve 6 and dissipates heat to the outside air to become a high-pressure two-phase refrigerant having a predetermined dryness. The refrigerant passes through the decompression means 12, but the decompression means 12 is fully opened during the reheat dehumidification operation, passes through the refrigerant pipe 3 with almost no pressure drop, and is led to the reheater 15. Here, the heat is released into the room air to be condensed and liquefied, and decompressed and expanded by the decompression means 16, and then is absorbed by the evaporator 17 from the room air and gasified. This gas refrigerant passes through the refrigerant pipe 4 and returns to the suction side of the compressor 5 through the four-way valve 6.
In the indoor unit 2, the air absorbed by the evaporator 17 and cooled and dehumidified and the air heated by the reheater 15 are mixed and blown out again into the room. Thus, the sucked room air hardly dehumidifies and is only dehumidified and blown out into the room. In order to reduce the heat transfer amount of the outdoor heat exchanger 7 in the outdoor unit 1, means such as reducing the rotational speed of the outdoor fan 8 are used.
[0004]
In the reheat dehumidifying operation, the refrigerant is circulated in the same manner as in the cooling operation, the heat radiation in the outdoor heat exchanger 7 is made small to prevent liquefaction, and the decompression means 12 is fully opened or bypassed to depressurize. The amount of reheat is obtained by conveying the high-pressure two-phase refrigerant to the reheater 15 that is an indoor heat exchanger. Here, if the refrigerant flowing into the reheater 15 becomes a liquid refrigerant, the latent heat of the refrigerant cannot be used, and only a small amount of reheat for the sensible heat of the liquid refrigerant can be obtained. For this reason, during the reheat dehumidifying operation, the outdoor unit 1 needs to send the two-phase refrigerant to the reheater 15 while maintaining a high pressure without condensing as much as possible in order to obtain a reheat amount.
[0005]
Also, for example, in general air conditioners used for business use, extension pipes of several meters to several tens of meters are used depending on the situation of the installation location. Usually, the amount of refrigerant corresponding to the extension pipe length at the installation site In order to avoid the need for adjustment, for example, an amount of refrigerant that does not require additional filling is enclosed in advance up to an extension pipe of 30 m. And when a liquid reservoir is arrange | positioned in a refrigerating cycle and an extension piping is short, it is designed so that an excess refrigerant | coolant can be accommodated in a liquid reservoir and it can drive | operate with an appropriate refrigerant | coolant amount.
However, in the reheat dehumidifying operation, the outlet of the outdoor heat exchanger 7 acting as a condenser is set in a two-phase state, so that the supercooled liquid existing at the outlet of the outdoor heat exchanger 7 is not necessary during the cooling operation, and the excess refrigerant is not used. Increase. When the surplus refrigerant cannot be stored in the liquid reservoir, the reheater 15 acting as a condenser in the indoor unit 2 is filled with the surplus refrigerant, and only the sensible heat of the liquid refrigerant contributes to the heating of the room air. If the reheater 15 is sufficiently large and does not become full even if all of the excess liquid refrigerant is accommodated, the above problem does not occur. However, normally, the indoor heat exchanger is divided into two and divided into one. It has a reheat function and cannot be so large. For this reason, the reheater 15 is filled with the liquid refrigerant, and only the reheat amount of the sensible heat can be obtained.
[0006]
In addition, if the refrigerant is filled according to the length of the extension pipe at the installation location, the refrigerant amount is charged after considering the installation location in advance, or the maximum amount of refrigerant is charged and the appropriate amount is set during installation. It is necessary to remove the filled refrigerant.
Also, even if the above work is performed and an amount of refrigerant according to the installation location is circulated in the refrigeration cycle, the cooling operation using the evaporation heat of the refrigerant, the heating operation using the condensation heat of the refrigerant, and both are used. In the reheat dehumidifying operation, the appropriate amount of refrigerant is different. If each operation is performed with the same amount of refrigerant, an efficient operation cannot be performed.
[0007]
[Problems to be solved by the invention]
As described above, in the case where a long extension pipe is previously provided in order to give versatility to the installation place, it is necessary to match the extension pipe to the installation place and to fill this with an appropriate amount of refrigerant. In addition, when a long extension pipe is prefilled with a refrigerant amount that does not require additional charging, an efficient air conditioner operation cannot be performed, and a sufficient reheat amount cannot be obtained particularly in a reheat dehumidification operation. There was a problem.
In addition, there is a problem that a refrigerant amount difference occurs even in a cooling operation, a heating operation, and a reheat dehumidifying operation, and each operation cannot be performed with an appropriate refrigerant amount.
[0008]
The present invention was made to solve the above problems, and by storing the excess liquid refrigerant, it is not necessary to fill an amount of refrigerant according to the installation location, and cooling operation, By reducing the operating efficiency of the heating operation and reheat dehumidification operation and sending the high-pressure two-phase refrigerant to the reheater without refilling the reheater with liquid refrigerant during the reheat dehumidification operation, It aims at obtaining the air conditioner from which calorie | heat amount is obtained.
[0009]
[Means for Solving the Problems]
In the air conditioner according to the present invention, a compressor, an outdoor heat exchanger, a flow rate control means, a first indoor heat exchanger, a dehumidification flow rate control means, and a second indoor heat exchanger are sequentially connected by a refrigerant pipe to supply a refrigerant. A refrigerating cycle to be circulated, a liquid reserving means disposed between an outdoor heat exchanger for reserving excess liquid refrigerant among the refrigerant circulating in the refrigerating cycle and a flow control means, and a liquid reserving means and a flow control means for reheat dehumidification. The liquid storage means detour for flowing the refrigerant circulating in a detour, and any part of the refrigerant from the branch to the liquid storage means detour to the outlet of the liquid storage means is cooled and liquefied and stored in the liquid storage means And a cooling means.
[0010]
In the air conditioner according to the present invention, a compressor, an outdoor heat exchanger, a flow rate control means, a first indoor heat exchanger, a dehumidification flow rate control means, and a second indoor heat exchanger are sequentially connected by a refrigerant pipe to supply a refrigerant. A refrigerating cycle to be circulated, a reserving means disposed between an outdoor heat exchanger for reserving excess liquid refrigerant among the refrigerant circulating in the refrigerating cycle, and a flow control means, and a liquid reservoir for a refrigerant flow path to the liquid reserving means. The reservoir means bypass that can bypass the means and the flow rate control means, and any part of the refrigerant from the branch to the reservoir means bypass circuit to the outlet of the reservoir means is cooled and liquefied and stored in the reservoir means And a cooling means, and the refrigerant flow from the outdoor heat exchanger is recirculated to the first indoor heat exchanger in parallel with the flow path through the liquid storage means and the flow path through the liquid storage means bypass circuit during reheating operation. It is what I sent.
[0012]
In the air conditioner according to the present invention, the refrigerant is cooled and liquefied by exchanging heat between the refrigerant from the branch to the reservoir means bypass and the outlet of the reservoir means and the suction side refrigerant of the compressor. It is.
[0015]
The air conditioner according to the present invention includes an inlet-side refrigerant pipe communicating the inlet of the first indoor heat exchanger and the inlet of the second indoor heat exchanger, the outlet of the first indoor heat exchanger, and the second indoor heat exchanger. An outlet side refrigerant pipe that communicates with the outlet, an inlet side opening / closing means that opens and closes each of the inlet side refrigerant pipe and the outlet side refrigerant pipe, and an outlet side opening / closing means. Thus, the first indoor heat exchanger and the second indoor heat exchanger can be connected in parallel.
[0016]
The air conditioner according to the present invention includes a bypass flow path installed in parallel with the dehumidification flow rate control means, and an opening / closing means provided in the bypass flow path, and the first indoor heat is released by opening the opening / closing means. The exchanger and the second indoor heat exchanger can be connected in series.
[0017]
In the air conditioner according to the present invention, the dehumidification flow rate control means has an orifice part and a rectifying part made of a porous permeation material at least one of the upstream and downstream sides thereof.
[0019]
The operation method of the air conditioner according to the present invention includes an outdoor unit preliminarily filled with a refrigerant amount considering an extension pipe having a predetermined length, and an indoor unit via an extension pipe having a length corresponding to the installation location on the site. Connecting.
[0020]
In the operation method of the air conditioner according to the present invention, when it is determined that excess liquid refrigerant has accumulated in the liquid storage means, the degree of supercooling in the refrigerant state near the heat exchanger outlet of the outdoor unit becomes a predetermined value or less. It is determined that excess liquid refrigerant has accumulated in the liquid storage means.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
1 is a refrigerant circuit diagram showing the configuration of an air conditioner according to Embodiment 1 of the present invention. In the figure, 1 is an outdoor unit, 2 is an indoor unit, 3 and 4 are refrigerant pipes, and the outdoor unit 1 and the indoor unit 2 are connected by a liquid pipe 3 and a gas pipe 4 which are refrigerant pipes to circulate the refrigerant. It constitutes the refrigeration cycle.
In the outdoor unit 1, 5 is a compressor, 6 is a flow path switching means, for example, a four-way valve, 7 is an outdoor heat exchanger, 8 is an outdoor blower that adjusts the amount of heat exchange between the outdoor heat exchanger 7 and the outside air, and 9 is For example, the flow rate control means such as an electric expansion valve is a first pressure reducing means, 10 is a liquid reservoir means, for example, a liquid receiver, and 11 is a cooling means for cooling the refrigerant in the liquid receiver 10. Here, the cooling means 11 is, for example, a suction pipe which is a suction side refrigerant pipe of the compressor 5, and the refrigerant in the liquid receiver 10 is cooled by inserting the suction pipe 11 into the liquid receiver 10. . Reference numeral 12 denotes a flow rate control means such as an electric expansion valve. Here, the second pressure reducing means, 13 is a liquid reservoir bypass circuit for bypassing the liquid receiver 10, the first and second pressure reducing means 9 and 12, and here a bypass. It is a flow path and is opened and closed by an on-off valve 14 that is an opening / closing means.
[0022]
In the indoor unit 2, 15 is a first indoor heat exchanger, 16 is a dehumidification flow rate control means which has an orifice and serves as a decompression means during reheat dehumidification, for example, a dehumidification valve, 17 is a second indoor heat exchanger, Reference numerals 18 and 19 denote on-off means, which are on-off valves here. The inlet-side on-off valve 18 is provided in an inlet-side refrigerant pipe 18a that communicates with the inlets of the first and second indoor heat exchangers 15 and 17, and the refrigerant pipe 18a Open and close. Similarly, the outlet side opening / closing valve 19 is provided in an outlet side refrigerant pipe 19a communicating with the outlets of the first and second indoor heat exchangers 15 and 17, and opens and closes the refrigerant pipe 19a. In addition, the refrigerant | coolant used with this air conditioner is R410A which is a low boiling point refrigerant | coolant, for example.
[0023]
In this air conditioner, cooling operation, heating operation, and reheat dehumidification operation can be performed. Hereinafter, reheating is performed so that the first indoor heat exchanger 15 functions as a condenser and the second indoor heat exchanger 17 functions as an evaporator. The operation of the dehumidifying operation will be described.
The first pressure reducing means 9 is opened at a predetermined opening, the second pressure reducing means 12 is opened, the on-off valve 14 is opened, the on-off valves 18 and 19 are closed, and the four-way valve 6 is connected as shown by a solid line. To do. FIG. 2 is a Ph diagram showing the operation of the refrigeration cycle when the reheat dehumidification operation is performed, in which the horizontal axis is the specific enthalpy h (kcal / kg) and the vertical axis is the pressure P (Mpa).
[0024]
A is a high-pressure gas discharged from the compressor 5, and is condensed and liquefied by exchanging heat with the outside air in the outdoor heat exchanger 7. Here, the outdoor blower 8 is at a very low speed or in a stopped state, is controlled to suppress heat radiation to the outside air, and becomes a high-pressure two-phase refrigerant state B having a predetermined dryness. The on-off valve 14 is opened, and most of the refrigerant flows through the bypass passage 13. Further, the refrigerant slightly flows through the first pressure reducing means 9 opened at a predetermined opening degree to the liquid receiver 10 as well. The high-pressure two-phase refrigerant, for example, about 40 ° C. flowing into the liquid receiver 10 is condensed and liquefied by exchanging heat with the suction pipe 11 having a low temperature, eg, about 5 ° C., and becomes a saturated liquid state C. To be stored. Part of the liquid refrigerant merges with the refrigerant flowing through the bypass flow path 13 through the second decompression means 12 that is fully open, and enters the high-pressure two-phase state D with a predetermined dryness to flow out of the outdoor unit 1. It flows to the tube 3.
[0025]
In the indoor unit 2, the on-off valves 18 and 19 are closed, and all of the high-pressure two-phase refrigerant E having a slight pressure drop from the state D through the liquid pipe 3 flows into the first indoor heat exchanger 15. The first indoor heat exchanger 15 radiates heat to the room air as a reheater, and the refrigerant condenses into the supercooled liquid state F. Thereafter, it flows into the dehumidifying valve 16 and is depressurized to be in the low pressure two-phase state G and flows into the second indoor heat exchanger 17. The second indoor heat exchanger 17 absorbs heat from room air as an evaporator, and the refrigerant evaporates to a state H. This refrigerant returns to the outdoor unit 1 through the gas pipe 4, exchanges heat with the refrigerant in the liquid receiver 10 through the suction pipe 11, becomes a superheated gas state I, and is sucked into the compressor 5 again.
[0026]
The indoor air sucked into the indoor unit 2 is heat-exchanged by the second indoor heat exchanger 17 and then heat-exchanged by the first indoor heat exchanger 15. That is, the sucked indoor air is cooled and dehumidified by evaporating the refrigerant in the second indoor heat exchanger 17. Next, the refrigerant is heated by being condensed in the first indoor heat exchanger 15 and blown out into the room. For this reason, the blown-out air is dehumidified only at a temperature almost equal to that of the sucked air, and dehumidification without lowering the room temperature becomes possible.
[0027]
As described above, by providing the cooling means 11 for cooling the two-phase refrigerant flowing into the liquid receiver 10, even if the refrigerant flowing out of the outdoor heat exchanger 7 is a high-pressure two-phase refrigerant, In addition, surplus refrigerant can be stored as liquid refrigerant. Furthermore, since the bypass flow path 13 that bypasses the liquid receiver 10 is provided, the high-pressure two-phase refrigerant that flows out of the outdoor heat exchanger 7 can be sent to the first indoor heat exchanger 15 that is a reheater. Become. By condensing the refrigerant in a high-pressure two-phase state with the reheater 15, a large amount of reheat is obtained as shown in J of FIG.
[0028]
In the case where there is no cooling means 11 for cooling the refrigerant in the liquid receiver 10 in the configuration of FIG. 1, in order to store the excess refrigerant as liquid refrigerant in the liquid receiver 10, the refrigerant state at the inlet of the liquid receiver 10 Need to be a liquid refrigerant, and inevitably the refrigerant state at the outlet of the outdoor heat exchanger 7 is also a liquid refrigerant. For this reason, the refrigerant flowing through the bypass channel 13 is also a liquid refrigerant, and the refrigerant flowing through the liquid pipe 3 is in a liquid state. Therefore, the refrigerant flowing into the reheater 15 becomes a liquid refrigerant, and only the amount of sensible heat of the high-temperature liquid refrigerant has the heating amount of the indoor air, and the reheating amount is insufficient.
[0029]
Further, when the bypass flow path 13 is not provided in the configuration of FIG. 1, the outlet of the outdoor heat exchanger can be a two-phase refrigerant, but when the liquid refrigerant is stored in the liquid receiver 10, the liquid receiver The refrigerant state at the outlet of 10 becomes the liquid refrigerant. For this reason, the refrigerant flowing through the liquid pipe 3 becomes a liquid refrigerant, and the reheater 15 is filled with the supercooled liquid as described above, and the reheat amount is insufficient.
[0030]
In the above, the refrigerant flowing on the suction side of the compressor 5 is used as the cooling means 11. However, if the cooling means 11 is configured to cool the refrigerant from the downstream side of the branch point to the bypass flow path 13 to the outlet of the liquid receiver 10, the high-pressure two-phase refrigerant that has flowed out of the outdoor heat exchanger 7. Can be cooled and liquefied and stored in the liquid receiver 10, and any configuration may be used.
For example, the cooling means 11 for cooling the refrigerant in the liquid receiver 10 as shown in FIG. 3 may be used. FIG. 3 is a block diagram showing the vicinity of the cooling means 11 and the liquid receiver 10, in which 29 is a pressure reducing means. The decompression means 29 decompresses the refrigerant liquid flowing out from the liquid receiver 10 to form a low-temperature two-phase refrigerant. The low-temperature two-phase refrigerant cools the high-temperature two-phase refrigerant in the liquid receiver 10 to form a liquid refrigerant, which is stored in the liquid receiver 10. The refrigerant that has absorbed heat from the refrigerant in the liquid receiver 10 becomes a gas refrigerant and is returned to the suction side of the compressor 5.
In this way, the refrigerant piping constituting the refrigeration cycle may be used, or another cooling means such as flowing cooling water may be used.
In addition, by bringing the refrigerant pipe from the downstream side of the branch point to the bypass flow path 13 to the inlet of the liquid receiver 10 into contact with the suction pipe, the refrigerant flowing through this portion of the refrigerant pipe is cooled and received as liquid refrigerant. It may be allowed to flow into the liquid vessel 10. Any refrigerant may be used as long as it cools and liquefies the refrigerant from the downstream of the branch point to the bypass flow path 13 to the outlet of the liquid receiver 10 and stores the liquid refrigerant in the liquid receiver 10.
[0031]
However, using the suction side refrigerant pipe for cooling liquefaction as shown in FIG. 1 also provides the following effects. The suction side refrigerant of the compressor 5 is controlled to become superheated gas. However, when the path balance of the pipes in the second indoor heat exchanger 17 is poor, the degree of superheat is significantly increased in a certain path, and the heat exchanger performance cannot be fully utilized. Further, when the suction-side refrigerant is in a two-phase state, the heat exchanger performance can be effectively used, but the compressor operation efficiency and reliability are reduced. Therefore, even if the refrigerant flowing out from the second indoor heat exchanger 17 absorbs heat from the refrigerant in the receiver 10, the refrigerant flowing out from the second indoor heat exchanger 17 is in a two-phase state, Can be returned to the compressor 5 as follows. For this reason, control becomes easy compared with always making the refrigerant | coolant of the 2nd indoor heat exchanger 17 exit into a gas refrigerant.
[0032]
The amount of liquid refrigerant that accumulates in the liquid receiver 10 during the reheat dehumidification operation can be controlled by the opening of the first decompression means 9 or the second decompression means 12. The ratio of the amount of the two-phase refrigerant flowing out from the outdoor heat exchanger 7 to the receiver 10 side and the amount flowing to the bypass channel 13 side can be controlled by the opening of the first decompression means 9. For example, the opening degree of the first pressure reducing means 9 is set so that the amount flowing to the liquid receiver 10 side: the amount flowing to the bypass flow path 13 side is about 3: 7. In the above description of the operation, the second pressure reducing means 12 is fully opened. However, the amount of flow to the liquid receiver 10 side is controlled by controlling the opening of the second pressure reducing means 12 with the first pressure reducing means 9 fully opened. It can also be controlled. The amount of liquid refrigerant that accumulates in the liquid receiver 10 is determined by the amount of refrigerant that flows to the liquid receiver 10 side.
[0033]
Next, the operation of the cooling operation will be described.
During the cooling operation, the first decompression means 9 and the second decompression means 12 are each opened at a predetermined opening, the on-off valve 14 provided in the bypass channel 13 is closed, and the on-off valves 18 and 19 of the indoor unit 2 are closed. Are open and the four-way valve 6 is connected and operated as shown by the solid line.
The gas refrigerant discharged from the compressor 5 is condensed and liquefied by the outdoor heat exchanger 7 through the four-way valve 6 and flows into the first decompression means 9 as supercooled liquid refrigerant. The first decompression means 9 is fixed at a predetermined opening, or the opening is controlled so that the degree of supercooling at the outlet of the outdoor heat exchanger 7 is adjusted to a predetermined value. It flows into the liquid receiver 10. In the liquid receiver 10, the refrigerant is condensed and condensed as a saturated liquid refrigerant by the suction pipe 11, and a part of the refrigerant flows to the second decompression means 12. The degree of opening of the second decompression means 12 is adjusted so that the degree of superheat of the suction gas of the compressor 5 becomes a predetermined value, and the refrigerant passing through the second decompression means 12 expands under reduced pressure to enter a low-pressure two-phase state and flows to the indoor unit 2. .
[0034]
Since the on-off valves 18 and 19 are opened in the indoor unit 2, the inlets and outlets of the first indoor heat exchanger 15 and the second indoor heat exchanger 17 are in communication with each other, and the refrigerant is heated by each indoor heat. It flows in parallel to the exchangers 15 and 17 and evaporates by exchanging heat with room air. It evaporates in the indoor unit 2 to become a gas refrigerant and returns to the outdoor unit 1 through the gas pipe 4. Then, heat is exchanged with the refrigerant in the liquid receiver 10 through the suction pipe 11 to be superheated and sucked into the compressor 5.
[0035]
Thus, in this embodiment, surplus refrigerant among the refrigerant sealed in the refrigerant circuit can be stored in the liquid receiver 10 while performing the cooling operation.
In the cooling operation, the on-off valves 18 and 19 are opened and the first and second indoor heat exchangers 15 and 17 are connected in parallel so that the refrigerant hardly passes through the dehumidifying valve 16. For this reason, a refrigerant | coolant flows through each indoor heat exchanger 15 and 17 in parallel, and the pressure loss at the time of passing through the dehumidification valve 16 does not arise. When the first and second indoor heat exchangers 15 and 17 are internally branched into a plurality of flow paths, and distributors (not shown) are used at the respective branch portions on the inlet side, A large pressure loss occurs. For example, when the first and second indoor heat exchangers 15 and 17 are connected in series, the first and second indoor heat exchangers 15 and 17 pass through the distributor twice, leading to a reduction in efficiency. In particular, when passing through the distributor on the inlet side of the second indoor heat exchanger 17, the refrigerant is evaporated by the first indoor heat exchanger 15, so that the refrigerant is in a two-phase state with a large amount of gas refrigerant, and the efficiency is greatly reduced. . On the other hand, in the configuration in which the first and second indoor heat exchangers 15 and 17 are connected in parallel as in this embodiment, it is possible to avoid a decrease in efficiency due to passing through the distributor twice during the cooling operation. . Furthermore, since it is not the structure which passes a distributor in a two-phase state with much gas refrigerant | coolant amount, a big efficiency fall can be avoided.
[0036]
Next, the heating operation will be described.
The first decompression means 9 and the second decompression means 12 are each opened at a predetermined opening, the on-off valve 14 is closed, the on-off valves 18 and 19 are opened, and the four-way valve 6 is connected and operated as indicated by a dotted line.
In the heating operation, the refrigerant is circulated in the opposite direction to the direction of the refrigerant circulation in the cooling operation by switching the four-way valve 6 as indicated by a dotted line. The gas refrigerant discharged from the compressor 5 flows to the indoor unit 2 through the four-way valve 6 and the gas pipe 4. Since the on-off valves 18 and 19 are opened in the indoor unit 2, the inlets and outlets of the first indoor heat exchanger 15 and the second indoor heat exchanger 17 are in communication with each other. The refrigerant flows in parallel to the indoor heat exchangers 15 and 17 and exchanges heat with indoor air to be condensed and liquefied. The refrigerant that has been condensed and liquefied into the supercooled liquid flows through the liquid pipe 3 to the outdoor unit 1 and flows into the second decompression means 12.
[0037]
The second decompression means 12 of the outdoor unit 1 is fixed at a predetermined opening, or the opening is controlled so that the degree of supercooling at the outlets of the indoor heat exchangers 15 and 17 is adjusted to a predetermined value, and the refrigerant that has passed therethrough Flows into the receiver 10 in a medium pressure two-phase state. In the liquid receiver 10, the refrigerant condenses and is stored as a saturated liquid through the suction pipe 11, and part of the refrigerant flows to the first decompression means 9. The opening of the first decompression means 9 is adjusted so that the degree of superheat of the suction gas of the compressor 5 becomes a predetermined value, and the refrigerant passing through the first decompression means 9 is decompressed and expanded into a low-pressure two-phase state to the outdoor heat exchanger 7. Inflow. The gas refrigerant evaporated by exchanging heat with the outside air in the outdoor heat exchanger 7 exchanges heat with the refrigerant in the liquid receiver 10 through the suction pipe 11 and is sucked into the compressor 5 as superheated gas.
[0038]
Thus, the surplus refrigerant | coolant of the refrigerant | coolant enclosed with the refrigerant circuit also in the heating operation accumulates in the liquid receiver 10, heating operation.
Even in this operation, the refrigerant is configured to flow through the indoor heat exchangers 15 and 17 in parallel, so that the pressure loss can be made lower than when connected in series and the operation efficiency is prevented from being lowered. Can do.
[0039]
In the refrigeration cycle, the refrigerant required for each operation is usually the largest in heating operation, preferably in the cooling operation, the amount of refrigerant is smaller than that in the heating operation, and in the reheat dehumidification operation, the amount of refrigerant is smaller than both. It is preferable. In this embodiment, in the cooling operation, the heating operation, and the reheat dehumidifying operation, the liquid refrigerant that is surplus in each operation among the encapsulated refrigerant is stored in the liquid receiver 10 while being operated, and each of the refrigerants is efficiently stored. You can drive. For this reason, it is not necessary to compensate or remove the difference in the amount of refrigerant generated in each operation from the outside.
In particular, if there is too much excess refrigerant in the reheat dehumidification operation, the first indoor heat exchanger 15 serving as a reheater is filled with liquid refrigerant, and a sufficient amount of reheat cannot be obtained. On the other hand, by providing the receiver 10 in the refrigeration cycle as a liquid storage means for storing excess liquid refrigerant, it is possible to prevent the reheater from becoming full of liquid refrigerant and to obtain a large amount of reheat. .
Further, even if the refrigerant amount is encapsulated assuming an extension pipe of about several tens of meters, surplus liquid refrigerant can be stored in the liquid receiver 10, so that the distance between the indoor unit 2 and the outdoor unit 1 can be easily achieved. The air conditioner can be made variable and has high versatility without restricting installation conditions in the distance between them.
The capacity of the liquid receiver 10 is a capacity that can accommodate almost all of the enclosed refrigerant amount, for example, an extension pipe of several tens of meters is considered here, and a capacity of about several liters is used. A capacity of several hundred cc is sufficient when the difference in refrigerant amount in each of the cooling operation, the heating operation, and the reheat dehumidifying operation is stored in the liquid receiver 10 without considering the extension pipe.
[0040]
In addition, since the liquid receiver 10 is provided on the high pressure side, it is possible to prevent a decrease in operating efficiency during the cooling operation and the heating operation that occurs in the configuration provided on the low pressure side. That is, when the liquid receiver 10 is installed as a liquid storage means on the low pressure side between the outlet of the second indoor heat exchanger 17 and the inlet of the compressor 5, the liquid refrigerant is stored in the accumulator and the refrigeration cycle is efficiently performed. It becomes difficult to drive. For example, at the time of cooling operation, the refrigerant becomes a two-phase refrigerant at the outlet of the indoor heat exchanger 17, and the liquid refrigerant is also mixed when returning the compressor oil accumulated in the accumulator together with the liquid refrigerant to the compressor 5. The refrigerant becomes slightly wet. The same applies to the heating operation. Furthermore, sudden expansion and contraction in the accumulator may cause pressure loss, which may lead to a decrease in operating efficiency due to a decrease in refrigerant flow rate.
In this embodiment, the excess liquid refrigerant is stored on the high-pressure side, so that the high-pressure two-phase refrigerant is sent to the reheater without reducing the operation efficiency during the cooling operation and the heating operation and during the reheat dehumidification operation. It is possible to obtain an air conditioner capable of performing the above.
[0041]
The air conditioner described here also has a heating function. However, when the heating function is not required, the four-way valve 6 which is a flow path switching means for switching the flow path is not necessary. Further, the first pressure reducing means 9 on the upstream side of the liquid receiver 10 is not necessarily required, and the same effect can be obtained even if omitted. In the cooling operation when the first decompression means 9 is not provided, the degree of supercooling at the outlet of the outdoor heat exchanger 7 may be controlled by the air volume of the outdoor fan 8.
[0042]
Embodiment 2. FIG.
FIG. 4 is a refrigerant circuit diagram showing a configuration of an air conditioner according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, or an equivalent part, and detailed description is abbreviate | omitted. In the first embodiment, the suction pipe is inserted into the liquid receiver 10 and the cooling means 11 for cooling and liquefying the refrigerant in the liquid receiver 10 is provided. However, in this embodiment, the cooling means is not provided and the surplus is not provided. Liquid refrigerant can be stored in the liquid receiver 10.
The first and second decompression means 9 and 12 in the figure are, for example, electric expansion valves, and have a configuration that can be fully closed together. The first and second decompression means 9 and 12 and the on-off valve 14 constitute a switching means for switching the refrigerant flow from the outdoor heat exchanger 7 to the liquid receiver 10 and the refrigerant flow to the liquid storage means bypass circuit 13. .
[0043]
Hereinafter, the operation of the reheat dehumidification operation will be described.
When the reheat dehumidifying operation is requested immediately after the air conditioner is turned on, the cooling operation is first performed before entering the reheat dehumidifying operation. The operation during this cooling operation is exactly the same as in the first embodiment, the on-off valve 14 of the outdoor unit 1 is closed, and the first decompression means 9 and the second decompression means 12 are each opened at a predetermined opening degree. The two on-off valves 18 and 19 of the indoor unit 2 are opened. In this state, after performing a cooling operation similar to the cooling operation described in the first embodiment for a while, a reheat dehumidifying operation is performed.
For example, the state of the refrigerant at the outlet of the outdoor heat exchanger 7 is monitored, and when the degree of supercooling becomes 5 ° C. or less, for example, about 2 ° C., a predetermined amount of excess liquid refrigerant is stored in the receiver 10. It can be determined that the amount of refrigerant stored and circulating in the refrigeration cycle has become an appropriate amount for the reheat dehumidification operation. Therefore, switch to reheat dehumidification operation. Here, it is preferable that the amount of circulating refrigerant in the refrigeration cycle in the reheat dehumidifying operation is smaller than that in the cooling operation. In normal cooling operation, the refrigerant is cooled at the outlet of the outdoor heat exchanger 7 at a degree of subcooling of about 5 ° C., and by controlling to below this degree of subcooling, the amount is more than the appropriate amount for the cooling operation. Liquid refrigerant can be stored in the liquid receiver 10.
[0044]
When switching to the reheat dehumidifying operation, the first decompression means 9 and the second decompression means 12 are completely closed, and the excess liquid refrigerant in the refrigeration cycle is isolated in the receiver 10. An amount of refrigerant less than the amount of the enclosed refrigerant circulates in the refrigeration cycle. In this state, the on-off valve 14 is opened and the on-off valves 18 and 19 in the indoor unit 2 are closed so as to constitute a circuit for reheat dehumidification operation. The supercooled liquid present in the outdoor heat exchanger 7 during the cooling operation moves into the reheater 15, but the excess liquid refrigerant is isolated in the liquid receiver 10, so that the reheater 15 is fully liquidated. Never become. In the reheat dehumidifying operation, the air flow of the outdoor blower 8 is adjusted so as to be extremely low speed or stopped, and the refrigerant state at the outlet of the outdoor heat exchanger 7 is operated so as to flow out in a high-pressure two-phase state. For this reason, the refrigerant state at the inlet of the reheater 15 can be operated with the high-pressure two-phase state, and the amount of reheat can be increased.
[0045]
In this way, surplus refrigerant is isolated in the receiver 10 and an appropriate amount of refrigerant is left in the reheat dehumidifying operation during the refrigeration cycle, thereby allowing the outlets B and D of the outdoor heat exchanger 7 and the reheater 15 to remain. It becomes possible to make the state of the refrigerant at the inlet E of the high pressure two-phase state. For this reason, even if the amount of enclosed refrigerant is large, the refrigerant can be sent to the indoor heat exchanger 15 in a high-pressure two-phase state, and a large amount of reheat can be obtained.
[0046]
In the above description, it is determined from the refrigerant state at the outlet of the outdoor heat exchanger 7 that excess liquid refrigerant has accumulated in the liquid receiver 10 during the cooling operation. However, the present invention is not limited to this. For example, when the cooling operation is performed with the air conditioner, the time during which the excess liquid refrigerant is accumulated may be obtained in advance, and the cooling operation may be performed for this time. Further, a liquid level sensor for measuring the liquid level of the liquid receiver 10 may be provided, and switching from the cooling operation to the reheat dehumidifying operation may be performed by detection of the liquid level sensor.
[0047]
In the above, the switching means for switching the refrigerant flow from the outdoor heat exchanger 7 to the liquid receiver 10 and the refrigerant flow to the liquid storage means bypass circuit 13 by the first and second pressure reducing means 9 and 12 and the on-off valve 14. It is composed. The switching means is not limited to this. For example, the flow path can be switched even if three-way valves are provided in the branching section and the merging section upstream and downstream of the liquid reservoir bypass circuit 13.
[0048]
Further, in this configuration, a cooling means for cooling the refrigerant in the liquid receiver 10 may be provided as in the first embodiment. By cooling the refrigerant in the liquid receiver 10, in the cooling operation performed before the reheat dehumidifying operation, even when the two-phase refrigerant flows into the liquid receiver 10, the liquid refrigerant can be obtained. The excess liquid refrigerant can be quickly stored in 10. As this cooling means, as shown in FIG. 1 and FIG. 3, a refrigerant pipe constituting the refrigeration cycle may be used, or another cooling means such as flowing cooling water may be used.
Further, as described in the first embodiment, a cooling means for cooling the refrigerant from the branching portion to the bypass flow path 13 to the inlet of the liquid receiver 10 may be provided.
In this embodiment, when the reheat dehumidification operation is requested immediately after the air conditioner is turned on, the cooling operation is performed before the reheat dehumidification operation, and the time for performing the cooling operation can be shortened. Has the effect that the user's request can be made quickly.
[0049]
When the reheat dehumidifying operation is requested after the cooling operation or the heating operation is performed after the air conditioner is turned on, it is necessary to perform the cooling operation in advance because excess refrigerant has accumulated in the liquid receiver 10. There is no. In this case, the first and second decompression means 9 and 12 are immediately closed completely to isolate excess refrigerant from the refrigeration cycle, the on-off valve 14 is opened, the on-off valves 18 and 19 are closed, and reheating is performed. Dehumidification operation may be performed.
[0050]
In addition, the cooling operation is performed to store the excess liquid refrigerant in the receiver 10 before the reheat dehumidification operation. However, when it is not desired to perform the cooling operation on a low temperature day such as a rainy season, the heating operation is first performed. You may make it drive | work. As described in the first embodiment, the excess liquid refrigerant can be stored in the liquid receiver 10 even by heating operation. Then, when the surplus liquid refrigerant accumulates to some extent in the liquid receiver 10 and an appropriate amount of refrigerant circulates in the refrigeration cycle for the reheat dehumidification operation, the reheat dehumidification operation may be switched. However, the circulation of the refrigerant in the reheat dehumidification operation is the same as that in the cooling operation, and the refrigerant circuit is more smoothly performed in the reheat dehumidification operation after the cooling operation than in the reheat dehumidification operation after the heating operation. Can be switched.
[0051]
In the configuration of FIG. 4, the cooling operation and the heating operation are performed in the same manner as in the first embodiment, and the configuration, operation, and effects are the same as in the first embodiment. Detailed description is omitted here.
[0052]
Further, as in the first embodiment, the following configurations, operations, and effects are achieved. That is, the first and second indoor heat exchangers 15 and 17 are connected in parallel during the cooling and heating operation so that the refrigerant does not pass through the dehumidifying valve 16. Thereby, by flowing a refrigerant | coolant in parallel to each indoor heat exchanger 15 and 17, the increase in a pressure loss can be prevented and the significant efficiency fall by the increase in a pressure loss can be avoided.
[0053]
Embodiment 3 FIG.
FIG. 5 is a refrigerant circuit diagram showing a configuration of an air conditioner according to Embodiment 3 of the present invention. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, 2, or an equivalent, and detailed description is abbreviate | omitted.
In the figure, reference numerals 30 and 31 denote open / close means, for example, open / close valves. Reference numeral 30 a denotes a gas refrigerant pipe, which is a flow path through which the gas in the liquid receiver 10 flows from the upper part of the liquid receiver 10 to the downstream of the second decompression means 12 via the on-off valve 30. Reference numeral 31 a denotes a bypass flow path that is connected in parallel with the dehumidifying valve 16. In this embodiment, the cooling means shown in the first embodiment is not provided between the outlet B of the outdoor heat exchanger 7 and the outlet C of the liquid receiver 10. The gas refrigerant pipe 30 a is opened and closed by opening and closing the on-off valve 30. Moreover, in the indoor unit 2, the on-off valve 31 is provided in the bypass flow path 31a, and by opening and closing the on-off valve 31, the bypass flow path 31a is opened and closed.
[0054]
The operation of the reheat dehumidifying operation in this embodiment will be described. In this embodiment, during the reheat dehumidification operation, the first and second decompression means 9 and 12 are controlled to be fully open so that there is no pressure drop, and the on-off valve 30 is opened and the on-off valve 31 is closed. The four-way valve 6 is connected as indicated by the solid line.
The high-temperature and high-pressure gas refrigerant discharged from the compressor 5 exchanges heat with the outside air in the outdoor heat exchanger 7 to be condensed and liquefied. Here, the outdoor blower 8 is at a very low speed or in a stopped state, and is controlled so as to suppress heat radiation to the outside air, and the refrigerant becomes a high-pressure two-phase refrigerant state with a predetermined dryness. The first decompression means 9 is open, and the refrigerant flows into the liquid receiver 10 in a high-pressure two-phase refrigerant state.
[0055]
The refrigerant flowing into the liquid receiver 10 in the high-pressure two-phase refrigerant state flows out as it is through the decompression means 12 as the high-pressure two-phase refrigerant when there is no gas refrigerant pipe 30a via the on-off valve 30. No excess liquid refrigerant accumulates in the vessel 10. In this embodiment, a gas refrigerant pipe 30 a is provided from the upper part of the liquid receiver 10. For this reason, the high-pressure two-phase refrigerant that has flowed in is separated and the gas refrigerant accumulates above the receiver 10, and the liquid refrigerant becomes saturated liquid refrigerant and accumulates below the receiver 10. The gas refrigerant in the upper part of the liquid receiver 10 flows through the gas refrigerant pipe 30 a via the on-off valve 30. On the other hand, a part of the saturated liquid refrigerant flows out from below the liquid receiver 10 through the second decompression means 12 and merges with the gas refrigerant. Then, it becomes a high-pressure two-phase refrigerant and flows to the indoor unit 2 through the liquid pipe 3. And it is sent to the 1st indoor heat exchanger 15 which functions as a reheater, and a high pressure two-phase refrigerant | coolant is condensed and liquefied here, passes through the dehumidification valve 16 as a supercooled liquid refrigerant. The pressure is reduced by the dehumidifying valve 16 to become a low-pressure two-phase refrigerant, evaporated in the second indoor heat exchanger 17, and again sucked into the compressor 5 through the gas pipe 4.
[0056]
In this configuration, unlike the first embodiment, no cooling means is provided between the outlet B of the outdoor heat exchanger 7 and the outlet C of the liquid receiver, and the liquid receiver 10 and the pressure reducing means 9 and 12 are not provided. Even without providing a detour liquid reservoir bypass circuit, the refrigerant at the inlet E of the reheater 15 is converted into a high-pressure two-phase refrigerant by combining the gas refrigerant in the receiver 10 with the liquid refrigerant at the outlet of the receiver 10. It becomes possible to do. In addition to the opening / closing operation by an electromagnetic valve or the like, the opening / closing valve 30 may be a variable throttle means that can adjust the flow rate on the gas side.
[0057]
Here, the amount of the refrigerant liquid accumulated in the liquid receiver 10 is determined by the degree of condensation in the outdoor heat exchanger 7. That is, it changes according to the air volume of the outdoor fan 8. Therefore, the degree of dryness at the outlet of the second indoor heat exchanger 17 may be monitored, and the air volume of the outdoor fan 8 may be controlled so as to achieve a predetermined degree of dryness.
[0058]
In this embodiment, a cooling means for cooling the refrigerant in the liquid receiver 10 may be provided as in the first embodiment. By cooling the refrigerant in the liquid receiver 10, the excess liquid refrigerant can be quickly and reliably stored in the liquid receiver 10. As this cooling means, as shown in FIG. 1 and FIG. 3, a refrigerant pipe constituting the refrigeration cycle may be used, or another cooling means such as flowing cooling water may be used. However, the refrigerant flowing into the liquid receiver 10 is in a high-pressure two-phase state.
[0059]
As described above, the gas refrigerant pipe 30a connecting the upper side of the liquid receiver 10 and the downstream side of the second decompression means 12 is provided, and the high-pressure two-phase refrigerant flowing out of the outdoor heat exchanger 7 is introduced into the liquid receiver 10. The liquid refrigerant is stored in the gas refrigerant, and the gas refrigerant flowing out from the gas refrigerant pipe 30a is joined with the liquid refrigerant flowing out from the lower side of the liquid receiver 10 so as to be sent to the first indoor heat exchanger 15 in a high-pressure two-phase state. Thus, even if the refrigerant flowing out of the outdoor heat exchanger 7 is a high-pressure two-phase refrigerant, the excess refrigerant is stored as a liquid refrigerant in the liquid receiver 10 and the high-pressure two-phase refrigerant is a reheater. It can be sent to the exchanger 15. A large amount of reheat can be obtained by condensing the refrigerant in a high-pressure two-phase state with the reheater 15.
[0060]
Next, operation during cooling operation will be described.
During the cooling operation, the open / close valve 30 of the outdoor unit 1 is closed, and the open / close valve 31 provided in the indoor unit 2 is opened. In this refrigerant circuit, the gas refrigerant discharged from the compressor 5 is condensed and liquefied by the outdoor heat exchanger 7 through the four-way valve 6 and flows into the first decompression means 9 as supercooled liquid. The decompression means 9 is fixed at a predetermined opening, or the opening is controlled so that the degree of supercooling at the outlet of the outdoor heat exchanger 7 is adjusted to a predetermined value, and the refrigerant that has passed therethrough is in a saturated liquid state in the receiver 10. Flow into. Here, the excess liquid refrigerant is stored in the liquid receiver 10, and part of the refrigerant flows to the second decompression means 12. The opening of the second decompression means 12 is adjusted so that the degree of superheat of the suction gas of the compressor 5 becomes a predetermined value, for example, about 10 ° C., and the refrigerant passing through the second pressure reducing means 12 is in a low-pressure two-phase state. Flows to unit 2.
[0061]
In the indoor unit 2, the refrigerant evaporates in the first indoor heat exchanger 15, passes through the open on-off valve 31 and the dehumidifying valve 16, and similarly evaporates in the second indoor heat exchanger 17. The gas refrigerant evaporated in the indoor unit 2 returns to the outdoor unit 1 through the gas pipe 4 and is sucked into the compressor 5. Thus, since the dehumidifying valve 16 and the on-off valve 31 are passed during the cooling operation, both the first and second indoor heat exchangers 15 and 17 can be used at almost the same evaporation temperature.
In the heating operation, the four-way valve 6 is connected in the cooling operation as shown by the dotted line to circulate the refrigerant in the opposite direction to the cooling operation, the heat exchangers 15 and 17 of the indoor unit 2 are the condenser, and the heat exchange of the outdoor unit 1 is performed. The vessel 7 is operated as an evaporator.
[0062]
The first indoor heat exchanger 15 and the second indoor heat exchanger 17 of the indoor unit 2 flow refrigerant in series with the first and second indoor heat exchangers in the cooling operation or the heating operation. As shown in the first and second embodiments, the operating efficiency is slightly reduced as compared with the configuration in which the refrigerant flows in parallel to the first and second indoor heat exchangers, but the air conditioning is inexpensive by reducing the number of switching means. There is an effect that a machine can be obtained. Moreover, you may connect in parallel by air_conditionaing | cooling operation and heating operation similarly to Embodiment 1,2. By flowing the refrigerant in parallel to the first and second indoor heat exchangers 15 and 17, pressure loss can be reduced as compared to when passing through the first and second indoor heat exchangers 15 and 17 in series. A reduction in efficiency can be prevented.
In the first and second embodiments, the opening / closing means 31 as shown in the third embodiment may be provided to allow the refrigerant to pass through the first and second indoor heat exchangers 15 and 17 in series. In this case, the operation efficiency is slightly reduced, but an effect is obtained that an inexpensive air conditioner can be obtained by reducing the number of opening / closing means.
[0063]
In this embodiment, surplus refrigerant among the refrigerant sealed in the refrigerant circuit can be stored in the liquid receiver 10 while performing a cooling operation or a heating operation. For this reason, the distance between the indoor unit 2 and the outdoor unit 1 can be easily made variable, and the air conditioner with high versatility can be obtained without restricting the installation conditions in the distance between them.
Moreover, since the liquid receiver 10 is provided on the high-pressure side as in the first embodiment, it is possible to prevent a decrease in operating efficiency during the cooling operation and the heating operation that occurs in the configuration provided on the low-pressure side. That is, by storing the excess liquid refrigerant on the high pressure side, it is possible to send the high-pressure two-phase refrigerant to the reheater without reducing the operation efficiency during the cooling operation and the heating operation and during the reheat dehumidification operation. An air conditioner can be obtained.
[0064]
The air conditioner described here also has a heating function. However, when the heating function is not required, the four-way valve 6 which is a flow path switching means for switching the flow path is not necessary. Furthermore, the first pressure reducing means 9 on the upstream side of the liquid receiver 10 in the refrigerant circulation in the cooling operation is not necessarily required, and the same effect can be obtained even if omitted.
[0065]
In the configurations of the first and third embodiments, even if the reheat dehumidifying operation is performed immediately after the power is turned on, the excess liquid refrigerant can be stored in the receiver 10 while being operated. There may be a step of first performing a heating operation or a cooling operation in the same manner as in FIG. It may be configured such that the reheat dehumidification operation is performed by switching the on-off valve and the flow rate control means after accumulating a certain amount of excess liquid refrigerant in the liquid receiver 10 during the cooling operation or heating operation. As described above, if a certain amount of excess refrigerant liquid is stored in the receiver 10 before performing the reheat dehumidifying operation, the refrigerant circulating in the refrigeration cycle can be quickly made into an appropriate amount, and an efficient operation can be performed. Can do.
[0066]
Embodiment 4 FIG.
Each of the first to third embodiments has a configuration in which the liquid receiver 10 is provided on the high-pressure side. In an air conditioner having a liquid storage means for storing excess liquid refrigerant and performing a reheat dehumidification operation, when the liquid storage means is provided on the high pressure side of the refrigerant circuit, the reheater 15 has a high pressure and high dryness. It was difficult to send the two-phase refrigerant. On the other hand, when the liquid storage means is provided on the low pressure side of the refrigerant circuit, the liquid receiver 10 gets wet on the suction side of the compressor 5 during the cooling operation and the heating operation. However, it is easy to store the excess liquid refrigerant in the liquid receiver 10 and to make the outlet of the outdoor heat exchanger 7 a high-pressure two-phase refrigerant.
Here, an embodiment of an air conditioner provided with a liquid storage means for storing excess liquid refrigerant on the low pressure side will be described. FIG. 6 is a refrigerant circuit diagram showing the configuration of an air conditioner according to Embodiment 4 of the present invention. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, or an equivalent part, and detailed description is abbreviate | omitted.
In this embodiment, a liquid receiver 10 serving as a liquid reservoir is provided on the low pressure side between the second indoor heat exchanger 17 and the compressor 5. Further, a decompression means 12 is provided as a flow rate control means for performing flow rate control between the outdoor heat exchanger 7 and the first indoor heat exchanger 15.
[0067]
The operation of the reheat dehumidifying operation in this embodiment will be described.
In this embodiment, during the reheat dehumidification operation, the decompression means 12 is opened and controlled so as not to drop the pressure, and the on-off valves 18 and 19 are closed. The four-way valve 6 is connected as indicated by the solid line.
The high-temperature and high-pressure gas refrigerant discharged from the compressor 5 exchanges heat with the outside air in the outdoor heat exchanger 7 to be condensed and liquefied. Here, the outdoor blower 8 is at a very low speed or in a stopped state, and is controlled so as to suppress heat radiation to the outside air, and the refrigerant becomes a high-pressure two-phase refrigerant state with a predetermined dryness. The decompression means 12 is open, and the refrigerant flows into the indoor unit 2 via the liquid pipe 3 while being in a high-pressure two-phase refrigerant state. And it is sent to the 1st indoor heat exchanger 15 which functions as a reheater, and a high pressure two-phase refrigerant | coolant is condensed and liquefied here, passes through the dehumidification valve 16 as a supercooled liquid refrigerant. The pressure is reduced by the dehumidifying valve 16 to become a low-pressure two-phase refrigerant, and evaporated in the second indoor heat exchanger 17 to become a low-pressure two-phase refrigerant. Then, it flows into the liquid receiver 10 through the gas pipe 4, and the gas refrigerant is sucked into the compressor 5 from the upper part of the liquid receiver 10. The liquid refrigerant that has flowed into the liquid receiver 10 accumulates in the liquid receiver 10 as an excess liquid refrigerant.
[0068]
In the cooling operation, the decompression means 12 is controlled to a predetermined opening, and the on-off valves 18 and 19 are opened. The four-way valve 6 is connected as shown by the solid line.
The high-temperature and high-pressure gas refrigerant discharged from the compressor 5 exchanges heat with the outside air in the outdoor heat exchanger 7 to be condensed and liquefied, and flows out of the outdoor heat exchanger 7 in a supercooled state. The decompression means 12 is controlled so that the refrigerant state at the outlet of the second indoor heat exchanger 17 has a predetermined wettability. The refrigerant expands under reduced pressure, passes through the liquid pipe 3 in the low-pressure two-phase refrigerant state, and enters the indoor unit 2. Flowing. And it sends in parallel with the 1st, 2nd indoor heat exchangers 15 and 17 which function as an evaporator, and heat-exchanges with indoor air here, it evaporates, and becomes a low-pressure two-phase refrigerant. Then, it flows into the liquid receiver 10 through the gas pipe 4, and the gas refrigerant is sucked into the compressor 5 from the upper part of the liquid receiver 10. The liquid refrigerant that has flowed into the liquid receiver 10 accumulates in the liquid receiver 10 as an excess liquid refrigerant.
[0069]
In the heating operation, the decompression means 12 is controlled to a predetermined opening degree, and the on-off valves 18 and 19 are opened. The four-way valve 6 is connected as indicated by the dotted line.
The high-temperature and high-pressure gas refrigerant discharged from the compressor 5 flows in parallel through the first and second indoor heat exchangers 15 and 17 functioning as condensers, where heat is exchanged with room air to condense and liquefy, It flows out from the 1st, 2nd indoor heat exchangers 15 and 17 in a supercooled state. Then, it flows to the outdoor unit 1 through the liquid pipe 3. The decompression means 12 is controlled so that the refrigerant state at the outlet of the outdoor heat exchanger 7 has a predetermined wettability, and the refrigerant flows into the outdoor heat exchanger 7 in a low-pressure two-phase refrigerant state. Then, the outdoor heat exchanger 7 functioning as an evaporator exchanges heat with the outside air and evaporates to become a low-pressure two-phase refrigerant. Thereafter, it flows into the liquid receiver 10, and the gas refrigerant is sucked into the compressor 5 from the upper part of the liquid receiver 10. The liquid refrigerant that has flowed into the liquid receiver 10 accumulates in the liquid receiver 10 as an excess liquid refrigerant.
[0070]
As described above, even when the liquid receiver 10 is provided on the low pressure side of the refrigeration cycle, it is possible to store the surplus liquid refrigerant, and to prevent the reheater 15 from becoming full and to increase the amount of reheat. . In particular, in the first to third embodiments, in order to store the liquid refrigerant in the liquid receiver 10 provided on the high-pressure side and send the refrigerant to the reheater 15 in a high-pressure two-phase state, the cooling means 11 and the liquid reservoir A detour 13 and a gas refrigerant pipe 30a are provided. On the other hand, in the configuration according to this embodiment, an air conditioner with a large amount of reheat can be obtained simply by providing the receiver 10 on the low pressure side of the refrigeration cycle.
[0071]
As described above, as shown in the first to fourth embodiments, the liquid receiver 10 serving as the liquid storage means is provided in the refrigeration cycle of the air conditioner having a reheating function, thereby storing excess liquid refrigerant. It is not necessary to fill the amount of refrigerant according to the installation location, and the amount of circulating refrigerant is too large to prevent the cooling operation, heating operation, and reheat dehumidification operation from decreasing, and reheat dehumidification. A large amount of reheat can be obtained by sending the high-pressure two-phase refrigerant to the reheater without filling the reheater with liquid refrigerant during operation.
[0072]
Here, the case where each air conditioner of Embodiment 1-Embodiment 4 is installed is demonstrated. For example, the outdoor unit 1 and the indoor unit 2 are assembled in the factory. Then, the outdoor unit 1 is preliminarily filled with a refrigerant amount in consideration of a predetermined length, for example, an extension pipe having a length of about 30 m. The outdoor unit 1 and the indoor unit 2 are standard specifications, and are installed as they are regardless of the installation location. However, the distance between the outdoor unit 1 and the indoor unit 2 varies depending on the installation location. For this reason, the outdoor unit 1 and the indoor unit 2 are connected via an extension pipe having a length corresponding to the installation location. The extension pipe corresponds to the refrigerant pipes 3 and 4 in each embodiment. Thereafter, cooling operation or heating operation is performed. In this way, the operation of storing the excess liquid refrigerant in the liquid storage means 10 does not require the operation of replenishing or removing the refrigerant, and an appropriate amount of refrigerant is supplied in the cooling operation, heating operation, or reheat dehumidification operation. Circulating and efficient operation can be performed.
[0073]
Embodiment 5 FIG.
Hereinafter, in each of the first to fourth embodiments, the dehumidifying flow rate control means 16 installed between the first and second indoor heat exchangers 15 and 17 in the indoor unit 2 will be described. When the dehumidifying flow rate control means, here, the dehumidifying valve 16 is constituted by a depressurizing means having a fixed opening degree, a capillary tube or one having an orifice portion can be used. Moreover, when it comprises with the pressure reduction means with a variable opening degree, an electric expansion valve etc. can be used. When an electric expansion valve that can be fully opened is used, the refrigerant pipes 18a and 19a as shown in FIGS. 1, 4, and 6, and the bypass passage 31a as shown in FIG. 5 are not necessary. .
[0074]
Here, the dehumidification valve 16 which is a pressure reduction means that can reduce refrigerant flow noise will be described. FIG. 7 is a cross-sectional configuration diagram illustrating the dehumidifying valve 16 according to the fifth embodiment. With reference to FIG. 7, the structure of the dehumidification valve 16 arrange | positioned in the indoor unit 2 is demonstrated. As described in the first to fourth embodiments, the dehumidifying valve 16 decompresses and expands the refrigerant flowing out from the first indoor heat exchanger 15 during reheat dehumidifying operation, and flows into the second indoor heat exchanger 17. It has a function to make it. In the cooling operation or the heating operation, most of the refrigerant flows around the dehumidification valve 16, so that the first and second indoor heat exchangers 15 and 17 are opened and the refrigerant is not decompressed. It is assumed that the refrigerant flows in the direction of the arrow in FIG. 7 during the reheat dehumidifying operation.
In the figure, reference numeral 21 denotes an orifice portion, which is a portion where the refrigerant is decompressed through the pores. 22 is an inlet side porous permeable material provided on the upstream side of the orifice portion 21, 23 is an outlet side porous permeable material provided on the downstream side of the orifice portion 21, and 24, 25, 26, and 27 are porous permeable materials 22, respectively. , 23 before and after.
[0075]
The high-pressure refrigerant condensed and liquefied flows into the space 24 through the first indoor heat exchanger 15 that functions as a reheater in the reheat dehumidification operation. Here, it collides with the inlet side porous permeable material 22, becomes a uniform flow and is rectified to reach the space 25. Next, the pressure is reduced by the orifice portion 21 and the low-pressure two-phase refrigerant is jetted into the space 26. The low-pressure two-phase refrigerant collides with the outlet-side porous permeable material 23, is rectified as a homogeneous flow, and reaches the space 27.
[0076]
For example, when the gas-liquid two-phase refrigerant passes through the decompression means in which the dehumidifying valve 16 is composed only of the orifice portion 21, a large refrigerant flow noise is generated. In particular, it is known that a large refrigerant flow noise is generated when the flow mode of the gas-liquid two-phase refrigerant is a slag flow. As a generation factor of the refrigerant flow noise, when the slag flow passes through a small hole such as the orifice portion 21 in the dehumidifying valve 16, a refrigerant vapor slag or refrigerant bubbles larger than the small hole are destroyed. Since vibration occurs due to the collapse of the refrigerant vapor slag or refrigerant bubbles, and the vapor refrigerant and the liquid refrigerant alternately pass through the small holes, the pressure loss generated when the refrigerant passes through the small holes greatly fluctuates. It is possible. In addition, a gas-liquid two-phase jet having a high speed and a large turbulence is formed at the outlet of the orifice portion 21, and pressure fluctuation due to the gas-liquid two-phase jet is also a cause of the refrigerant flow noise. Therefore, the gas-liquid two-phase refrigerant is rectified by the porous permeable material 22 disposed on the upstream side of the orifice portion 21, and the liquid and the gas are homogeneously mixed into the gas-liquid two-phase flow (the vapor refrigerant and the liquid refrigerant are well mixed). State), the refrigerant flow noise generated near the orifice 21 in the dehumidifying valve 16 can be reduced.
[0077]
In addition, when the high-speed refrigerant that has passed through the orifice portion 21 directly collides with the inner wall of the dehumidifying valve 16, the refrigerant flow noise also increases. On the other hand, by providing the porous permeable material 23 on the downstream side of the orifice portion 21, the refrigerant flow is rectified and homogenized, and the refrigerant flow noise is reduced.
[0078]
As described above, by arranging the porous permeable materials 22 and 23 such as foam metal before and after the orifice portion 21, a homogeneous flow is formed in the space 25 before being decompressed and the space 27 after being decompressed. . For this reason, the discontinuous sound and pressure pulsation resulting from a gas-liquid two-phase flow are reduced.
Here, the porous permeable materials 22 and 23 have, for example, a diameter of air holes (pores inside the porous body through which fluid can permeate) of 100 μm or more and 1000 μm or less, and a thickness of 1 mm to 10 mm. A foam metal made of Ni-Cr or stainless steel is used. In view of the effect of lowering the refrigerant flow noise, the diameter of the air hole is preferably 1000 μm or less. Further, in the normal refrigeration cycle, a strainer is provided to remove dust circulating in the circulating refrigerant. By setting the grain size of the strainer to be equal to or greater than that of the strainer, it is possible to prevent the porous permeable materials 22 and 23 from being clogged with dust. Therefore, the diameter of the air hole is preferably set to 100 μm or more.
The porous permeation material is not limited to the foam metal, but a sintered metal obtained by sintering a metal powder, a porous permeation material made of ceramics, a metal mesh, a plurality of metal meshes, or a number of metal meshes. The same effect can be obtained even with a sintered wire mesh or a laminated wire mesh that is laminated and sintered.
[0079]
Further, the decompression means 16 shown in FIG. 7 has a configuration in which the porous permeable materials 22 and 23 are provided on both the upstream side and the downstream side of the orifice portion 21, but the configuration provided on one of the upstream side and the downstream side. But you can. If a porous permeation material is provided in at least one of them, the refrigerant flow noise can be reduced by rectifying and homogenizing the refrigerant as compared with the configuration of only the orifice portion.
[0080]
Further, in each of Embodiments 1 to 5, R410A of HFC refrigerant was used as the refrigerant of the refrigeration cycle. This refrigerant is a refrigerant suitable for global environmental conservation that does not destroy the ozone layer, and is a low-boiling point refrigerant. Compared to R22 that has been used as a conventional refrigerant, this refrigerant has a higher refrigerant vapor density and a slower flow rate of the refrigerant. Even if an inexpensive solenoid valve having a small diameter is used for a plurality of used flow rate control means, the pressure drop is small and the cost can be reduced.
[0081]
However, the refrigerant is not limited to R410A, and may be R407C, R404A, and R507A that are HFC refrigerants. Further, from the viewpoint of preventing global warming, a mixed refrigerant such as R32 alone, R152a alone, or R32 / R134a, which is an HFC refrigerant having a small global warming potential, may be used.
Further, HC refrigerants such as propane, butane and isobutane, natural refrigerants such as ammonia, carbon dioxide and ether, and mixed refrigerants thereof may be used.
[0082]
【The invention's effect】
As described above, the air conditioner according to the present invention includes a compressor, an outdoor heat exchanger, a flow rate control means, a first indoor heat exchanger, a dehumidification flow rate control means, and a second indoor heat exchanger with refrigerant piping. A refrigerating cycle that sequentially connects and circulates the refrigerant, a liquid reservoir means that is disposed between the outdoor heat exchanger that stores excess liquid refrigerant among the refrigerants that circulate in the refrigeration cycle, and a flow control means, and a liquid reservoir that is used for reheat dehumidification The liquid reservoir means detour for flowing the refrigerant that circulates in a diverted manner with respect to the means and the flow rate control means, and any part of the refrigerant from the branch to the liquid reservoir detour to the outlet of the liquid reservoir means is cooled and liquefied. Cooling means for storing the liquid in the liquid storage means, so that it can be operated efficiently by circulating an appropriate amount of refrigerant in each of the cooling operation, heating operation or reheat dehumidification operation, and excess liquid refrigerant is stored in the liquid storage means. 1st indoor heat exchange Vessel is prevented from becoming flooded with liquid refrigerant, amount of reheat-rich reheat dehumidification operation can be performed.
[0083]
In the air conditioner according to the present invention, a compressor, an outdoor heat exchanger, a flow rate control means, a first indoor heat exchanger, a dehumidification flow rate control means, and a second indoor heat exchanger are sequentially connected by a refrigerant pipe to supply a refrigerant. A refrigerating cycle to be circulated, a reserving means disposed between an outdoor heat exchanger for reserving excess liquid refrigerant among the refrigerant circulating in the refrigerating cycle, and a flow control means, and a liquid reservoir for a refrigerant flow path to the liquid reserving means. The reservoir means bypass that can bypass the means and the flow rate control means, and any part of the refrigerant from the branch to the reservoir means bypass circuit to the outlet of the reservoir means is cooled and liquefied and stored in the reservoir means Cooling means, and the first indoor heat exchange in parallel with the flow path through the liquid storage means and the flow path through the liquid storage means bypass circuit during reheating operation of the refrigerant from the outdoor heat exchanger So that it can be used for cooling operation, heating operation, or reheat dehumidification operation. Each can be operated efficiently by circulating an appropriate amount of refrigerant, and the excess liquid refrigerant can be stored in the liquid storage means, and the first indoor heat exchanger can be prevented from becoming full of liquid refrigerant. Many reheat dehumidification operations can be performed.
[0085]
In the air conditioner according to the present invention, the refrigerant is cooled and liquefied by exchanging heat between the refrigerant from the branch to the reservoir means bypass and the outlet of the reservoir means and the suction side refrigerant of the compressor. Further, it is possible to prevent the operation efficiency from being lowered in the cooling operation or the heating operation, to perform the reheat dehumidification operation with a large amount of reheat, and to reliably make the compressor suction side refrigerant state a gas refrigerant.
[0088]
The air conditioner according to the present invention includes an inlet-side refrigerant pipe communicating the inlet of the first indoor heat exchanger and the inlet of the second indoor heat exchanger, the outlet of the first indoor heat exchanger, and the second indoor heat exchanger. An outlet side refrigerant pipe that communicates with the outlet, an inlet side opening / closing means that opens and closes each of the inlet side refrigerant pipe and the outlet side refrigerant pipe, and an outlet side opening / closing means. Since the first indoor heat exchanger and the second indoor heat exchanger can be connected in parallel, the pressure loss chamber can be reduced as compared with a configuration in which the first indoor heat exchanger and the second indoor heat exchanger are connected in series in the cooling operation or the heating operation, and the highly efficient cooling operation or heating operation. Is possible.
[0089]
The air conditioner according to the present invention includes a bypass flow path installed in parallel with the dehumidification flow rate control means, and an opening / closing means provided in the bypass flow path, and the first indoor heat is released by opening the opening / closing means. Since the exchanger and the second indoor heat exchanger can be connected in series, the switching operation is simpler than the configuration in which the exchanger and the second indoor heat exchanger are connected in parallel in the cooling operation or the heating operation, and the number of open / close means can be reduced and the configuration can be reduced.
[0090]
In the air conditioner according to the present invention, the dehumidification flow rate control means includes the orifice part and a rectification part made of a porous permeation material in at least one of the upstream side and the downstream side thereof. Noise due to gas-liquid two-phase flow can be reduced.
[0092]
The operation method of the air conditioner according to the present invention includes an outdoor unit preliminarily filled with a refrigerant amount considering an extension pipe having a predetermined length, and an indoor unit via an extension pipe having a length corresponding to the installation location on the site. And an air conditioner that is relatively easy to install, so that excess liquid refrigerant can be stored in the liquid storage means and a reheat dehumidification operation with a large amount of reheat can be performed. .
[0093]
In the operation method of the air conditioner according to the present invention, when it is determined that excess liquid refrigerant has accumulated in the liquid storage means, the degree of supercooling in the refrigerant state near the heat exchanger outlet of the outdoor unit becomes a predetermined value or less. Since it is determined that the excess liquid refrigerant has accumulated in the liquid reservoir means, the excess liquid refrigerant can be reliably accumulated in the liquid reservoir means, and a reheat dehumidification operation with a large amount of reheat can be performed.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram showing a configuration of an air conditioner according to Embodiment 1 of the present invention.
FIG. 2 is a Ph diagram showing the refrigeration cycle operation according to the first embodiment.
FIG. 3 is a configuration diagram showing another cooling means according to the first embodiment.
FIG. 4 is a refrigerant circuit diagram showing a configuration of an air conditioner according to Embodiment 2 of the present invention.
FIG. 5 is a refrigerant circuit diagram showing a configuration of an air conditioner according to Embodiment 3 of the present invention.
FIG. 6 is a refrigerant circuit diagram showing a configuration of an air conditioner according to Embodiment 4 of the present invention.
FIG. 7 is a cross-sectional configuration diagram showing a dehumidifying flow control means according to Embodiment 5 of the present invention;
FIG. 8 is a refrigerant circuit diagram showing a conventional air conditioner.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outdoor unit, 2 Indoor unit, 3, 4 Refrigerant piping, 5 Compressor, 6 Flow path switching means, 7 Outdoor heat exchanger, 8 Outdoor fan, 9 Flow control means, 10 Liquid storage means, 11 Cooling means, 12 Flow rate Control means, 13 Liquid storage means bypass, 14 Opening / closing means, 15 First indoor heat exchanger, 16 Dehumidification flow control means, 17 Second indoor heat exchanger, 18 Inlet side opening / closing means, 18a Inlet side refrigerant piping, 19 Outlet side opening / closing means, 19a Outlet side refrigerant piping, 21 Orifice part, 22, 23 Porous permeating material, 24-27 space, 30 Opening / closing means, 30a Gas refrigerant piping, 31 Opening / closing means, 31a Bypass flow path.

Claims (9)

圧縮機、室外熱交換器、流量制御手段、第１室内熱交換器、除湿用流量制御手段、第２室内熱交換器を冷媒配管で順次接続して冷媒を循環させる冷凍サイクルと、前記冷凍サイクルを循環する冷媒のうち余剰液冷媒を溜める前記室外熱交換器と前記流量制御手段の間に配置された液溜め手段と、再熱除湿時に前記液溜め手段と前記流量制御手段に対し迂回して循環する冷媒を流す液溜め手段迂回路と、前記液溜め手段迂回路への分岐部から前記液溜め手段の出口までのいずれか一部の冷媒を冷却液化して前記液溜め手段に貯留する冷却手段と、を備えたことを特徴とする空気調和機。  A refrigeration cycle in which a compressor, an outdoor heat exchanger, a flow rate control means, a first indoor heat exchanger, a dehumidification flow rate control means, and a second indoor heat exchanger are sequentially connected by refrigerant piping to circulate the refrigerant, and the refrigeration cycle A liquid storage means disposed between the outdoor heat exchanger for storing excess liquid refrigerant among the refrigerant circulating through the flow rate control means, and bypassing the liquid storage means and the flow rate control means during reheat dehumidification. Reservoir means detour for flowing circulating refrigerant, and cooling that liquefies any part of the refrigerant from the branching portion to the reserving means detour to the outlet of the reservoir means and stores it in the reservoir means And an air conditioner. 圧縮機、室外熱交換器、流量制御手段、第１室内熱交換器、除湿用流量制御手段、第２室内熱交換器を冷媒配管で順次接続して冷媒を循環させる冷凍サイクルと、前記冷凍サイクルを循環する冷媒のうち余剰液冷媒を溜める前記室外熱交換器と前記流量制御手段の間に配置された液溜め手段と、前記液溜め手段への冷媒流路に対し前記液溜め手段と前記流量制御手段を迂回可能な液溜め手段迂回路と、前記液溜め手段迂回路への分岐部から前記液溜め手段の出口までのいずれか一部の冷媒を冷却液化して前記液溜め手段に貯留する冷却手段と、を備え、前記室外熱交換器からの冷媒を前記再熱運転時に前記液溜め手段を介す流路と前記液溜め手段迂回路を介す流路を並行して前記第１室内熱交換器へ送るようにしたことを特徴とする空気調和機。  A refrigeration cycle in which a compressor, an outdoor heat exchanger, a flow rate control means, a first indoor heat exchanger, a dehumidification flow rate control means, and a second indoor heat exchanger are sequentially connected by refrigerant piping to circulate the refrigerant, and the refrigeration cycle The liquid storage means disposed between the outdoor heat exchanger for storing excess liquid refrigerant among the refrigerant circulating through the flow rate control means, and the liquid storage means and the flow rate with respect to the refrigerant flow path to the liquid storage means A liquid reservoir bypass circuit capable of bypassing the control means and any part of the refrigerant from the branch to the liquid reservoir bypass circuit to the outlet of the liquid reservoir is cooled and liquefied and stored in the liquid reservoir. Cooling means, and the refrigerant from the outdoor heat exchanger in the first chamber in parallel with the flow path through the liquid storage means and the flow path through the liquid storage means bypass circuit during the reheating operation Air conditioning characterized by being sent to a heat exchanger . 前記液溜め手段迂回路への分岐部から前記液溜め手段の出口までの冷媒と前記圧縮機の吸入側冷媒とを熱交換することで前記冷媒を冷却液化するようにしたことを特徴とする請求項１又は２に記載の空気調和機。  The refrigerant is cooled and liquefied by exchanging heat between a refrigerant from a branch portion to the liquid reservoir bypass and an outlet of the liquid reservoir and a suction side refrigerant of the compressor. Item 3. An air conditioner according to item 1 or 2. 前記第１室内熱交換器の入口と前記第２室内熱交換器の入口を連通する入口側冷媒配管と、前記第１室内熱交換器の出口と前記第２室内熱交換器の出口を連通する出口側冷媒配管と、前記入口側冷媒配管と前記出口側冷媒配管のそれぞれを開閉する入口側開閉手段と出口側開閉手段と、を備え、前記入口側開閉手段と出口側開閉手段を開放して前記第１室内熱交換器及び第２室内熱交換器を並列接続可能としたことを特徴とする請求項１乃至３のいずれか１項に記載の空気調和機。  An inlet-side refrigerant pipe that communicates the inlet of the first indoor heat exchanger and the inlet of the second indoor heat exchanger, and the outlet of the first indoor heat exchanger and the outlet of the second indoor heat exchanger are communicated. An outlet side refrigerant pipe, an inlet side opening / closing means and an outlet side opening / closing means for opening and closing each of the inlet side refrigerant pipe and the outlet side refrigerant pipe, and opening the inlet side opening means and the outlet side opening / closing means. The air conditioner according to any one of claims 1 to 3, wherein the first indoor heat exchanger and the second indoor heat exchanger can be connected in parallel. 前記除湿用流量制御手段と並列に設置されたバイパス流路と、このバイパス流路に設けられた開閉手段と、を備え、前記開閉手段を開放して前記第１室内熱交換器及び前記第２室内熱交換器を直列接続可能としたことを特徴とする請求項１乃至４のいずれか１項に記載の空気調和機。  A bypass flow path installed in parallel with the dehumidification flow rate control means, and an opening / closing means provided in the bypass flow path, the opening / closing means being opened to open the first indoor heat exchanger and the second The air conditioner according to any one of claims 1 to 4, wherein the indoor heat exchanger can be connected in series. 前記除湿用流量制御手段は、オリフィス部とその上流及び下流の少なくともどちらか一方に多孔質透過材による整流部を有することを特徴とする請求項１乃至５のいずれか１項に記載の空気調和機。  The air conditioning according to any one of claims 1 to 5, wherein the dehumidifying flow rate control means includes an orifice part and a rectifying part made of a porous permeation material in at least one of the upstream part and the downstream part thereof. Machine. 請求項１乃至６のいずれかに記載の空気調和機に対して、室外ユニット及び室内ユニットに設けられた熱交換器のいずれか一方を凝縮器としいずれか他方を蒸発器として冷房運転又は暖房運転を行うステップと、前記冷房運転又は暖房運転で前記液溜め手段に余剰液冷媒が溜まったと判断した後に前記室外ユニット側からの冷媒を前記液溜め手段迂回路を介して前記室内ユニット側に流すステップと、を備えたことを特徴とする空気調和機の運転方法。  The air conditioner according to any one of claims 1 to 6, wherein either one of the outdoor unit and the heat exchanger provided in the indoor unit is a condenser, and the other is an evaporator. And a step of causing the refrigerant from the outdoor unit side to flow to the indoor unit side via the liquid storage unit bypass circuit after determining that excess liquid refrigerant has accumulated in the liquid storage unit in the cooling operation or heating operation. And a method for operating the air conditioner. 所定長さの延長配管を考慮した冷媒量を予め充填した前記室外ユニットを、現地でその設置場所に応じた長さの延長配管を介して前記室内ユニットと接続するステップと、を備えたことを特徴とする請求項７記載の空気調和機の運転方法。 Connecting the outdoor unit pre-filled with an amount of refrigerant in consideration of an extension pipe having a predetermined length to the indoor unit via an extension pipe having a length corresponding to the installation location on site. The method of operating an air conditioner according to claim 7, 前記液溜め手段に余剰液冷媒が溜まったことを判断する際に、前記室外ユニットの熱交換器出口付近冷媒状態の過冷却度が所定の値以下になったときに前記液溜め手段に余剰液冷媒が溜まったと判断することを特徴とする請求項７記載の空気調和機の運転方法。 When it is determined that excess liquid refrigerant has accumulated in the liquid storage means, the excess liquid is stored in the liquid storage means when the degree of supercooling in the refrigerant state near the heat exchanger outlet of the outdoor unit becomes a predetermined value or less. 8. The method of operating an air conditioner according to claim 7, wherein it is determined that the refrigerant has accumulated .
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