JP3918421B2

JP3918421B2 - Air conditioner, operation method of air conditioner

Info

Publication number: JP3918421B2
Application number: JP2000286908A
Authority: JP
Inventors: 雅弘中山; 義浩田辺; 茂樹大西; 浩招牧野; 悟平國
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2000-09-21
Filing date: 2000-09-21
Publication date: 2007-05-23
Anticipated expiration: 2020-09-21
Also published as: JP2002089988A

Description

【０００１】
【発明の属する技術分野】
本発明は、冷凍サイクルの凝縮熱を室内空気への加熱源として利用する空気調和機において、冷房、除湿、暖房、等の各運転時における、温度と湿度の制御性を高め、また冷媒流動音を低減することにより、室内の温度と湿度と騒音に対する快適性を向上させる空気調和機に関するものである。
【０００２】
【従来の技術】
従来の空気調和機においては、主として回転数可変型圧縮機等が用いられ、空調負荷の変動に対応している。しかし冷房低能力運転時は圧縮機回転数が低下するものの、蒸発温度も上昇して室内空気の露点温度以上となり、除湿できないという問題点があった。
【０００３】
冷房低能力運転時の除湿能力を向上させる従来技術として、特開平９−４２７０６号公報の図１７に示す空気調和機がある。この装置によると、圧縮機、四方弁、室内熱交換器、第１流量制御弁、室外熱交換器を備え、室内熱交換器を室内機の前面から背面にかけて送風機を囲むように配置した空気調和機において、前記室内熱交換器を熱的に分割しその間に第２流量制御弁１０を設けるとともに、この第２流量制御弁１０の冷媒流れ上流側を再熱器、冷媒流れ下流側を蒸発器として動作させる運転モードにて、除湿能力を確保している。この時、前面上段から背面に設置された熱交換器が再熱器として作用している。
【０００４】
また特開平９−４２７０６号公報における冷媒回路図を図１８に示す。圧縮機、四方弁、室内熱交換器、第１流量制御弁、室外熱交換器を備え、前記室内熱交換器を熱的に分割しその間に第２流量制御弁１０を設けている。冷媒の流れ方向は、冷房回路での再熱除湿運転時は四方弁を冷房方向として図１８の実線の矢印方向となり、第２流量制御弁１０を主たる流量制御弁として用いている。また暖房運転時は、四方弁を暖房方向として図１８の点線の矢印方向となり、第１流量制御弁２４を主たる流量制御弁として用いている。
【０００５】
【発明が解決しようとする課題】
しかし特開平９−４２７０６号公報においては、室内熱交換機内に第２流量制御弁が設置されているため、ここでの冷媒圧力損失が大きく、通常冷房運転や暖房運転での効率低下を引き起こすという問題点がある。
【０００６】
加えて特開平９−４２７０６号公報において用いている図１８に示す第２流量制御弁は、通常のオリフィスタイプの膨張弁を用いているため、冷媒流動音が大きいという問題点がある。送風音と比較して十分に小さいものではなく、防音吸音材を貼るなどの対策が必要となる。
【０００７】
なお、従来の空気調和機においては冷媒としてＲ２２が使用されていたが、オゾン層破壊防止のため、Ｒ４１０Ａなどへの代替化が進行中である。Ｒ４１０ＡはＲ２２より動作圧力が高くなるため、第２流量制御弁での差圧も大きくなり、冷媒流動音がより大きくなるという問題点が生じる。
【０００８】
加えて特開平９−４２７０６号公報における冷媒回路、図１８において、暖房回路にて再熱除湿運転をしようとして冷媒流れを暖房方向に切り換えた時、第２流量制御弁下流側の室内熱交換器と室外熱交換器が蒸発器として動作するが、室外熱交換器容量が大きいため、室内熱交換器の蒸発温度が室内空気の露点温度以下に下がらず、除湿できないという問題点がある。
【０００９】
本発明は、以上に述べたような問題点を解決するためになされたものであり、冷凍サイクルの凝縮熱を室内空気への加熱源として利用する空気調和機において、冷房、除湿、暖房、各運転時における、温度と湿度の制御性を高め、冷房シーズン暖房シーズンを問わず再熱除湿運転を実現するとともに、通常冷房・暖房運転時の効率も向上させ、加えて従来冷媒だけでなく、代替冷媒においてもその特性を生かし、冷媒流動音を低減することを目的とする。
【００１０】
【課題を解決するための手段】
本発明にかかわる空気調和機は、圧縮機、室内熱交換器、第１流量制御弁、室外熱交換器、四方弁を有し冷媒を循環させる冷媒回路を備えた空気調和機において、前記室内熱交換器を分割しその間に設けられた第２流量制御弁と、前記第１流量制御弁と前記室内熱交換器又は前記室外熱交換器との間に設けられた気液分離容器と、前記気液分離容器から圧縮機吸入に接続されたバイパス回路上に第３流量制御弁を有するガスバイパス回路と、を備え、前記四方弁を暖房回路として前記冷媒が圧縮機吐出、四方弁、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、気液分離容器、第３流量制御弁、圧縮機吸入へと流れ、前記第３流量制御弁は全開とし、前記第１流量制御弁を全閉として、前記第２流量制御弁にて流量制御を行う暖房回路での再熱除湿運転モードを有するものである。
【００１３】
本発明にかかわる空気調和機は、前記四方弁を冷房回路として、前記冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、四方弁、圧縮機吸入へと流れるとともに、前記気液分離容器にて分離されたガス冷媒が前記第３流量制御弁を通って前記圧縮機吸入へと流れ、前記第２流量制御弁は全開とし、前記第１流量制御弁にて主たる冷媒回路の流量制御を、前記第３流量制御弁にて前記ガスバイパス回路の流量制御を行う冷房運転モードを有するものである。
【００１４】
本発明にかかわる空気調和機は、四方弁を暖房回路として、冷媒が圧縮機吐出、四方弁、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、気液分離容器、第１流量制御弁、室外熱交換器、四方弁、圧縮機吸入へと流れ、前記第３流量制御弁は全閉とし、前記第２流量制御弁を全開として、第１流量制御弁にて流量制御を行う暖房運転モードを有するものである。
【００１５】
本発明にかかわる空気調和機は、暖房除霜運転の際、前記四方弁を冷房回路に切り換え、前記冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、第３流量制御弁、圧縮機吸入へと流れ、前記第１流量制御弁、前記第３流量制御弁を全開とした運転モードを有するものである。
【００１６】
本発明にかかわる空気調和機は、圧縮機、室内熱交換器、第１流量制御弁、室外熱交換器、四方弁を有し冷媒を循環させる冷媒回路を備えた空気調和機において、前記室内熱交換器を分割しその間に設けられた第２流量制御弁と、前記第１流量制御弁と前記室内熱交換器又は前記室外熱交換器との間に設けられた気液分離容器と、前記気液分離容器から圧縮機吸入に接続されたバイパス回路上に第３流量制御弁を有するガスバイパス回路と、前記室内熱交換器を設けた室内ユニットの室内空気を吸い込む吸い込み口に設けられた温湿度検知手段にて検知した吸込み空気の温湿度とあらかじめ設定された温湿度との偏差により室内の空調付加を求める潜熱顕熱負荷検知装置と、を備え、少なくとも冷房回路での再熱除湿運転及び暖房回路での再熱除湿運転の運転モードを有し、前記潜熱顕熱負荷検知装置にて検知した負荷が、あらかじめ各運転モードにて設定した潜熱顕熱能力制御範囲内か否かにより、運転モードを切り換えて動作するものである。
【００１７】
本発明の請求項８に係る空気調和機は、圧縮機、室内熱交換器、第１流量制御弁、室外熱交換器、四方弁を備えた空気調和機において、室内熱交換器を分割しその間に第２流量制御弁を設けるとともに、第１流量制御弁と室内熱交換器の間に気液分離容器を有し、気液分離容器からのガスバイパス回路が圧縮機吸入に接続されていて、このガスバイパス回路上に第３流量制御弁を備えるとともに、四方弁を冷房回路として、冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、四方弁、圧縮機吸入へと流れ、第３流量制御弁は全閉とし、第１流量制御弁又は第２流量制御弁にて流量制御を行う第１の運転モードと、四方弁を暖房回路として、冷媒が圧縮機吐出、四方弁、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、気液分離容器、第３流量制御弁、圧縮機吸入へと流れ、第３流量制御弁は全開とし、第２流量制御弁にて流量制御を行う第２の運転モードとを有し、第１の運転モードと前記第２の運転モードは交互に切り替え可能なものである。
【００１８】
本発明の請求項９に係る空気調和機は、四方弁を冷房回路に切り換え、冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、四方弁、圧縮機吸入へと流れるとともに、気液分離容器にて分離されたガス冷媒が第３流量制御弁を通って圧縮機吸入へと流れ、第２流量制御弁は全開とし、第１流量制御弁にて主たる冷媒回路の流量制御を、第３流量制御弁にてガスバイパス回路の流量制御を行う第３の運転モードを有し，第１運転モードと交互に切替可能なものである。
【００１９】
本発明の請求項１０に係る空気調和機の、第１流量制御弁の弁開度制御は室内熱交換器出口冷媒過熱度に相当する値を、第３流量制御弁の弁開度制御は、圧縮機吸入冷媒過熱度、圧縮機吐出冷媒過熱度、圧縮機吐出冷媒温度に相当する値を目標として流量制御を行う運転モードを有する。
【００２０】
本発明の請求項１１に係る空気調和機の、第３流量制御弁の弁開度制御は、圧縮機回転数に応じて流量制御を行う運転モードを有する。
【００２１】
本発明の請求項１２に係る空気調和機は、四方弁を冷房回路に切り換え、冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、第３流量制御弁、圧縮機吸入へと流れ、第１流量制御弁、第３流量制御弁を全開とした第４の運転モードを有する。
【００２２】
本発明の請求項１３に係る空気調和機は、第２流量制御弁の冷媒流れ上流側を再熱器、冷媒流れ下流側を蒸発器として動作させる再熱除湿運転モードの再熱器の冷媒流れ上流側に、再熱器と熱的に遮断された補助熱交換器を備えたものである。
【００２３】
本発明の請求項１４に係る空気調和機は、補助熱交換器の冷媒流路を一系統としたものである。
【００２４】
本発明の請求項１５に係る空気調和機は、第１流量制御弁もしくは第２流量制御弁もしくは第３流量制御弁の流動抵抗体として、冷媒流れ方向に連通する多孔質透過材を用いたものである。
【００２５】
本発明の請求項１６に係る空気調和機は、第２流量制御弁の代わりに絞り装置として、オリフィスとこの冷媒流れ上流方向、もしくは下流方向、もしくは上下流方向に、オリフィスを挟み込む構造で冷媒流れ方向に連通する多孔質透過材を配置、または多孔質透過材を単独に配置して、流動抵抗体として作用させるとともに、この絞り装置をバイパスする冷媒流路と、このバイパス流路を開閉する手段とを備えたものである。
【００２６】
本発明の請求項１７に係る空気調和機は、バイパス流路を開閉する手段として、双方向流れに対して封止可能な開閉弁を用いたものである。
【００２７】
本発明の請求項１８に係る空気調和機は、第１流量制御弁と気液分離容器を接続した回路に、冷房方向、暖房方向とも、第１流量制御弁にて減圧された冷媒を気液分離容器にて気液分離する冷媒流れとなる様に第１流量制御弁から前記気液分離容器への流れが常に一定なる切替回路を接続したものである。
【００２８】
本発明の請求項１９に係る空気調和機は、圧縮機吸入側に液だめ容器を設けたものである。
【００２９】
本発明の請求項２０に係る空気調和機は、第３流量制御弁を毛細管と電磁開閉弁で構成したものである。
【００３０】
本発明の請求項２１に係る空気調和機は、冷媒としてＲ４１０ＡまたはＲ３２またはＲ２９０を用いたものである。
【００３１】
本発明の請求項２２に係る空気調和機は、冷媒としてＲ２９０またはＲ３２を用い、第１流量制御弁および第２流量制御弁および第３流量制御弁の少なくともいずれか１つの流量制御弁に全閉機能を備えるとともに、冷媒漏れを検知する手段を備え、冷媒漏れを検知した場合には前記流量制御弁を全閉する手段を備えたものである。
【００３２】
本発明の請求項２３に係る空気調和機の運転方法は、室内空気状態の目標値を設定する空気状態設定手段と，前記室内の空気状態を検出する空気状態検出手段と、室内熱交換器への送風量を調整する室内送風量調整手段と，室外熱交換器への送風量を調整する室外送風量調整手段と、圧縮機の回転数を調整する圧縮機回転数調整手段と、第１流量制御弁の開度を調整する第１流量制御弁開度調整手段と、第２流量制御弁の開度を調整する第２流量制御弁開度調整手段と、を備えた空気調和機において、前記第２流量制御弁の冷媒流れ上流側の室内熱交換器を再熱器、冷媒流れ下流側の室内熱交換器を蒸発器として動作させる再熱除湿運転モードにて空気調和機を運転するステップと、運転中の前記空気調和機の室内空気状態の目標値と検出値から室内での潜熱および顕熱の空調負荷の目標値と検出値の差異を求めるステップと，前記室内の潜熱および顕熱の空気負荷の差異を少なくする方向に、前記室内熱交換器への送風量、室外熱交換器への送風量、圧縮機の回転数、第１流量制御弁の開度、及び第２流量制御弁の開度の少なくともいずれか１つを変化させるステップと，を備えたものである。
【００３３】
【発明の実施の形態】
実施の形態１．
本発明の第１の実施形態による空気調和機を図１、２に示す。図１（ａ）は冷媒回路図で、図２は室内ユニットの断面図である。図１（ａ）に示す冷媒回路図では、室外ユニット１７は、回転数可変型圧縮機２１、四方弁２２、室外熱交換器２３、第１流量制御弁２４、気液分離容器８２、気液分離容器８２からガス冷媒を分離し圧縮機吸入に接続されるガスバイパス回路８０、このガスバイパス回路８０上の第３流量制御弁８１より構成され、室内ユニット１８の室内熱交換器は、熱的に分割された第１室内熱交換器２５と第２室内熱交換器２７より構成され、その間に第２流量制御弁１０を設けている。冷媒としてＲ４１０ＡもしくはＲ３２もしくはＲ２９０を使用している。図２において、室内ユニット内に組み込まれた室内熱交換器は例えばプレートフィンチューブ型熱交換器で多段曲げ構造となっており、前面から背面にかけて送風機５（貫流送風機の例を示す）を囲むように設置され、第２流量制御弁１０を備えている。１１は伝熱管、１２は手前側の伝熱管接続配管、１３は奥側の伝熱管接続配管、２８は伝熱フィンである。この室内熱交換器は前面下段部分４、前面正面部分２、前面上段斜め部分１、背面部分３の４段曲げ構造であり、各々の部分は熱的に遮断されている。６は前面下段部分熱交換器用ドレンパン、７は背面熱交換器用ドレンパン、８は空気吸込グリル、９は吸込空気流れ方向、２９は空気吹出口、１９は吹出空気流れ方向である。９の方向より空気吸込グリル８から吸い込まれた空気は、送風機５によって吸引され、吸込空気流れ方向９ｄから前面下段部分４、９ｂから前面正面部分２、９ａから前面上段斜め部分１、９ｃから背面部分３の各々４カ所を通って熱交換し、空気吹出口２９より、１９の方向に吹き出される。
【００３４】
図１（ａ）の冷媒回路に設けられた第１流量制御弁２４、第２流量制御弁１０、第３流量制御弁８１、四方弁２２の各弁が冷房，暖房，冷房再熱除湿，暖房再熱除湿，暖房除霜などいろいろな運転モードで示す動作を図１（ｂ）に示す。図中全開は開度調整を行うことなく全開状態を示し，単に開は流量制御弁の開度調整を行うことを示す。四方弁の冷房方向，暖房方向は冷媒の流れの方向が冷房時の流れ，暖房時の流れであることを示す。図２に示す室内熱交換器のパスパターンでは、図１（ａ）に示す四方弁２２が冷房回路での再熱除湿運転時の方向となった時、すなわち冷媒流れ方向が実線の矢印方向時、冷媒入口配管が１５、冷媒出口配管が１６となり、それぞれ図１における第１流量制御弁２４から配管１５に、配管１６から四方弁２２に接続されている例を示している。再熱器となる室内熱交換器の第１室内熱交換器２５は、第２流量制御弁１０の冷媒流れ上流側となる前面上段斜め部分１と前面正面部分２に配置され、蒸発器となる室内熱交換器の第２室内熱交換器２７は、第２流量制御弁１０の冷媒流れ下流側となる背面部分３と前面下段部分４に配置され、蒸発器の下側にも再熱器が配置された構造となっている。以上、図１の冷媒回路において運転時の動作を以下に説明する。
【００３５】
図１（ａ）において、冷房回路での再熱除湿運転時は、第１流量制御弁２４の開度を開き気味とし第３流量制御弁８１を閉じて、第２流量制御弁１０を主たる減圧装置として使用する冷凍サイクルとなる。この冷房回路での再熱除湿運転時の冷凍サイクルにおける、圧力−エンタルピ線図を図３に示す。図３中のＡ〜Ｇは、図１（ａ）中の冷媒回路におけるＡ〜Ｇにそれぞれ対応し、冷房回路での再熱除湿運転時の冷媒流れ方向を図１（ａ）中の実線の矢印で示す。圧縮機２１から吐出され、四方弁２２を通った冷媒は、Ａ点から室外熱交換器２３にて凝縮しＢ点となり、第１流量制御弁２４で若干減圧されＣ点となり、第１室内熱交換器２５に流入する。この時第１室内熱交換器２５は再熱器として作用し、Ｄ点まで再凝縮する。この後第２流量制御弁１０を通ってＥ点まで減圧され、第２室内熱交換器２７に流入する。この時第２室内熱交換器２７は蒸発器として作用し、Ｆ点まで蒸発して、圧縮機２１の吸入Ｇに戻る冷凍サイクルとなる。この時室内ユニット１８では、第２室内熱交換器２７で冷却除湿された空気と第１室内熱交換器２５で加熱された空気が混合して吹き出す。よってこの冷房回路での再熱除湿運転時には、室温の低下を防ぎながら除湿を行うことができる。
【００３６】
前述した再熱除湿運転時には、図２に示すように、再熱器となる第１室内熱交換器２５が、第２流量制御弁の冷媒流れ上流側となる前面上段斜め部分１と前面正面部分２に送風機５を囲むように配置され、蒸発器となる室内熱交換器の第２室内熱交換器２７が、第２流量制御弁の冷媒流れ下流側となる背面部分３と前面下段部分４に送風機５を囲むように配置されているので、室内ユニット１８の斜め上面９ａや前面９ｂから吸い込み加熱された空気と、背面９ｃや前面下部９ｄから冷却除湿された空気とが送風機５により効率よく混合される。特に従来例と比較して、背面部分３を蒸発器として作用させることにより、背面部分３を通過し除湿冷却された空気９ｃと、前面上段斜め部分１を通過し加熱された空気９ａとが特によく混合される。従って吹出口２９から吹き出される空気１９は、吸込空気と比較して温度低下がなく除湿された空気となり、しかも空気に温度ムラがなく吹き出されるため、非常に快適な室内環境を作ることができる。
【００３７】
また、加熱された空気９ａ、９ｂと冷却除湿された空気９ｃ、９ｄが、送風機５に分布状態で吸い込まれて効率よく混合されるため、送風機５や吹出口２９の壁面等に温度ムラがなくなり、局所的に冷却された部分に露が付着し、吹出し空気とともに吹出口２９から露が吹き出してしまうといった、信頼性上の問題点を解消できる。また、加熱された空気９ａ、９ｂの両側から冷却除湿された空気９ｃと９ｄとが混合されるから、空気の混合が２箇所で行なえるので、冷却除湿された空気と加熱された空気の大きな固まり同士が接触することによりその界面で露が発生し、吹出し空気とともに吹出口２９から露が吹き出してしまうといった、信頼性上の問題点も解消できる。
【００３８】
また、蒸発器となる第２室内熱交換器２７が、背面部分３と前面下段部分４に送風機５を囲むように配置されており、それぞれの熱交換器下部にドレンパン６、７を設置しているので、吹出し空気とともに吹出口２９から露が吹き出してしまうことなく、また、第１室内熱交換器２５が第２室内熱交換器２７から発生する露の滴下を受けることなく熱交換器３、４を伝って除湿した露を直接ドレンパン６、７で回収することができるので、信頼性を確保することができる。
【００３９】
続いて図１（ａ）に、暖房回路での再熱除湿運転時の冷媒流れ方向を点線の矢印で示す。暖房回路での再熱除湿運転での冷凍サイクルにおける、圧力−エンタルピ線図を図４に示す。図４中のＡ〜Ｇは、図１中の冷媒回路におけるＡ〜Ｇにそれぞれ対応する。圧縮機２１から吐出され、四方弁２２を通った冷媒は、Ｆ点から第２室内熱交換器２７にて凝縮しＥ点となり、第２流量制御弁１０で減圧されＤ点となり、第１室内熱交換器２５に流入する。この時第２室内熱交換器２７は再熱器として作用し、第１室内熱交換器２５は蒸発器として作用する。この後Ｃ点を通って気液分離容器８２に流入し、ガスバイパス回路８０、第３流量制御弁８１を通って圧縮機２１の吸入Ｇに戻る冷凍サイクルとなる。なおＥ点にて過冷却がつかない場合の動作は、図４の点線のＥ‘，Ｄ‘の動作となる。このとき第１流量制御弁２４は全閉として室外熱交換器２３に冷媒が流入しないようにしており、第３流量制御弁８１は全開として流動抵抗とならないようにしている。このため冷媒は第１室内熱交換器２５で蒸発しなければならないため、その蒸発温度は室内空気温度より必ず低くなる。ただし蒸発温度が室内空気温度より低いが、室内空気の露点温度以下とならないと除湿できないが、この場合は蒸発器として作用する第１室内熱交換器２５に熱交換器に流れる冷媒の温度を配管の外部から計測する蒸発温度検知装置を設け、室内空気の露点温度を検知する装置である室内温度と湿度の計測装置を吸込口に設ける等各計測装置を室内ユニットに備え計測値により蒸発温度が室内の露点温度より高い場合は、室内送風機５の風量を低下させて蒸発温度を下げたり、圧縮機回転数を増速させて冷媒流量を増加させ蒸発温度を下げたりして、室内空気の露点温度以下としてやればよい。これにより室内ユニット１８では、外気温条件によらずに第１室内熱交換器２５で冷却除湿された空気と第２室内熱交換器２７で加熱された空気が混合して吹き出す。
【００４０】
暖房回路での再熱除湿運転と冷房回路での再熱除湿運転の特性を、図３、図４をもとに比較してみる。図３における再熱器での冷媒の潜熱エネルギーの差であるエンタルピ差はＣ−Ｄであるが、図４における再熱器でのエンタルピ差はＦ−Ｅであり、Ｅ点で過冷却がつかない場合（図４中、点線のＥ´−Ｄ´の断熱減圧となる）のＥ´点となっても図３より大きい。従って冷媒の異なる状態点におけるエネルギ差を表すエンタルピ差が大きいので、暖房回路の方が再熱器での熱交換量を非常に多く取ることが出来る。従って暖房回路にて再熱除湿運転を行うことにより、室温低下がない除湿、もしくは室温を上げつつも除湿すると行ったことが可能となる。すなわち、外気温条件、冷房シーズン、暖房シーズンを問わずに、必要とされる空調負荷に応じて冷房回路での再熱除湿運転と暖房回路での再熱除湿運転を状態に応じて切り換えたり，交互に切り替えて運転することにより、室温を制御（低下、同等、上昇）しながらの除湿を行うことが出来る。また気液分離容器８１を通って冷媒が圧縮機に吸入されることにより、余剰な冷媒を貯留することができ、さらに圧縮機の液バック運転を防ぐことができ、圧縮機の信頼性向上や、圧縮機吐出温度の上昇を得ることができる。圧縮機の吐出温度が上昇すれば、第２室内熱交換器２７での熱交換量を増やすことができ、より広い暖房顕熱潜熱制御範囲を得ることができる。
【００４１】
次に本実施例における冷房運転時の動作について説明する。図１（ｂ）の様に第２流量制御弁１０は全開にして、第１流量制御弁２４を主たる減圧装置として使用し、気液分離容器８２で分離されたガスバイパス回路８０上のガスバイパス流量を第３流量制御弁８１にて制御する冷凍サイクルとなる。この冷房運転時の冷凍サイクルにおける、圧力−エンタルピ線図を図５に示す。図５中のＡ〜Ｇは、図１中の冷媒回路におけるＡ〜Ｇにそれぞれ対応し、冷房運転時の冷媒流れ方向を図１中の実線の矢印で示す。圧縮機２１から吐出され、四方弁２２を通った冷媒は、Ａ点から室外熱交換器２３にて凝縮しＢ点となり、第１流量制御弁２４で減圧され気液分離容器８２にてＣ’点となる。気液分離容器８２にて分離された冷媒のうち、ガス冷媒はＨ点、液冷媒はＣ点となる。Ｃ点の液冷媒は第１室内熱交換器２５に流入し、蒸発を開始する。この後第２流量制御弁１０を通って第２室内熱交換器２７に流入し蒸発する。一方Ｈ点のガス冷媒は第３流量制御弁８１にて若干減圧され、第２室内熱交換器２７を通って蒸発したガス冷媒と合流しＧ点となり、圧縮機２１に吸入される冷凍サイクルとなる。
【００４２】
図５には、比較のため気液分離容器を用いない通常の冷凍サイクルを点線で示している。第１流量制御弁２４で減圧され気液分離容器にてＣ’点となった冷媒は、第１室内熱交換器２５に流入し、蒸発を開始する。この後第２流量制御弁１０を通って第２室内熱交換器２７に流入し蒸発する。そしてＧ’点にて圧縮機２１に吸入される冷凍サイクルとなる。なお図５において気液分離容器を用いない通常の冷凍サイクルでは、図１（ａ）に示すＣ点とＣ’点は、同一となる。
【００４３】
実際の冷凍サイクルにおいては冷媒が流れる冷媒配管に流動抵抗が存在するため、特に低圧となる蒸発器において図５のＣ’−Ｇ’点に示すような圧力損失が生じる。特に再熱除湿冷媒回路を組み込んだ冷凍サイクルにおいては、室内ユニットに第２流量制御弁１０を設ける必要があり、冷媒配管の構成が複雑となって、室内ユニットでの圧力損失が大きくなる欠点がある。そこでこの圧力損失を低減することが出来れば、冷凍サイクルの効率を飛躍的に高めることが出来、再熱除湿冷媒回路を組み込んだ空気調和機のエネルギ効率を高めることが出来る。ガスを上部から液を下部から循環させる容器である気液分離容器を用いた本冷凍サイクルでは、Ｃ’点での二相冷媒の乾き度が０．２前後のため、冷媒ガスと冷媒液の質量流量比は２０％と８０％である。そして気液分離により冷媒ガスはバイパス回路を通って圧縮機吸入に流れるので、Ｃ点を通って室内熱交換器に流れる冷媒流量は、全流量（＝気液分離容器を用いない場合の流量）の８０％程度となる。本冷凍サイクルの蒸発能力は、気液分離容器を用いない冷凍サイクルと同等となる。この理由は、本冷凍サイクルでは気液分離により液冷媒が室内熱交換器に流入するので冷媒エンタルピ差は気液分離容器を用いない冷凍サイクルより２０％程度増加し、冷媒流量が８０％になるものの、冷媒流量×エンタルピ差で表される蒸発能力はほぼ等しくなるためである。従って本冷凍サイクルにおいて、室内熱交換器を流れる冷媒流量が全流量（＝気液分離容器を用いない場合の流量）の８０％程度まで減少する結果、圧力損失が気液分離容器を用いない冷凍サイクルの６０％から７０％程度まで減少（圧力損失は冷媒流量の約１．７５乗に比例ため）するので、冷凍サイクルの効率を飛躍的に高めることが出来、再熱除湿冷媒回路を組み込んだ空気調和機のエネルギ効率を高めることが可能となった。
【００４４】
なお冷媒流量が少ない場合は、室内熱交換器での圧力損失は微小なものとなるので、本冷凍サイクルにおいて第３流量制御弁８１を全閉としても良い。また圧縮機回転数変化時等、冷媒流量が変化した場合は、ガスバイパス流量も変化するので、圧縮機回転数に応じて第３流量制御弁８１弁開度を調節することにより、適切なガスバイパス流量を確保して、空気調和機のエネルギ効率が常に最高となるような運転を実現することができる。また第３流量制御弁８１を毛細管と電磁開閉弁（図示せず）で構成すれば、低コスト化が図れる。
【００４５】
次に本実施例における暖房除霜運転時の動作について説明する。第１流量制御弁２４、第３流量制御弁８１は全開にして、第２流量制御弁１０を全閉として制御する冷凍サイクルとなる。この暖房除霜運転時の本冷凍サイクルにおける冷媒流れ方向を、図１中の実線の矢印で示す。圧縮機２１から吐出され、四方弁２２を通った高温高圧の冷媒は、Ａ点から室外熱交換器２３に流入し、室外熱交換器２３に付着した霜を解かす。この後Ｂ点を通って第１流量制御弁２４、気液分離容器８２のガスバイパス回路８０のＨ点を通って、Ｇ点で圧縮機２１に吸入される冷凍サイクルとなる。
【００４６】
従来の暖房除霜運転時の冷凍サイクルでは、圧縮機２１から吐出され、四方弁２２を通った高温高圧の冷媒は、Ａ点から室外熱交換器２３に流入し、室外熱交換器２３に付着した霜を解かす。この後Ｂ点、第１流量制御弁２４、Ｃ点を通って、室内熱交換器に流入しＦ点、四方弁２２を経て、Ｇ点で圧縮機２１に吸入される冷凍サイクルとなる。このためガスバイパス回路８０を利用した本冷凍サイクルの方が、圧縮機吐出を出てから圧縮機吸入に至るまでの冷媒経路が短く、急速に除霜運転を立ち上げることが出来、除霜運転時間の短縮が達成できて快適な空調空間を得ることが出来る。また従来の暖房除霜運転では冷媒が室内ユニットに流れるため、室内熱交換器が蒸発器として作用し、室内空気が冷却される欠点がある。しかし本冷凍サイクルでは冷媒を室内ユニットに流さないため、室内空気から熱を奪い取ることはなく、室内環境を快適に保つことが出来る。また気液分離容器８２は、圧縮機吸入直前で気液分離と冷媒貯留の役目も果たすため、圧縮機へ気液二相冷媒が吸入されるのを防ぎ、液バック運転による圧縮機損傷を防ぎ、圧縮機の信頼性を向上させることができる。なお、付着した霜の量によっては、除霜開始前半は本冷凍サイクルによる除霜運転、後半は従来の冷凍サイクルによる除霜運転、またはその逆と運転モードを切り換えても良い。また、暖房運転時間を調節して付着する霜の量を調整しても良い。霜の量は例えば室内熱交換器に温度センサーを取り付けてこのセンサーで計測される蒸発温度ＥＴが低いほど霜の量が多いと判断できるし，あるいは室外熱交換器圧力である蒸発圧力や圧縮機吸入圧力などを判断の材料にしても良い。
【００４７】
本空気調和機の制御方法について図６を用いて説明する。図６は、本発明の冷媒回路および運転制御に用いる各種センサ・アクチュエータ制御機器の構成図で、図１と同一の部位には、同一の番号を付けている。室内ユニット１８の構造は例えば図２である。以下、この実施形態における空気調和機の運転制御法について説明する。空気調和機には、室内の居住者が好みの温湿度環境を設定するための設定装置７５が備えられている。この設定装置７５では、例えば温度と湿度両方を設定するが、この設定温湿度は居住者がそれぞれの設定値を室内ユニット１８に付属するリモコンから直接入力してもよい。また室内ユニット１８の室内空気を吸い込む吸込口には、室内の温度および湿度を検知するために、室内ユニット１８の吸い込み空気温度センサー６５および湿度センサー６６がそれぞれ設けられている。
【００４８】
空気調和機運転時には、設定温湿度と現在の室内吸込み空気温湿度との差を温湿度偏差として演算し、これら偏差より、第１の演算装置６７にて室内の空調負荷である潜熱および顕熱負荷を推算する。そしてこれら偏差がゼロ、あるいは所定の値以内となるように、すなわち室内の潜熱及び顕熱の空気負荷の差異を小さくする方向に、信号線７３を通じて空気調和機の各アクチュエータ、圧縮機２１回転数、室外ファン６１回転数、室内ファン６３回転数、第１流量制御弁２４の絞り開度、および第２流量制御弁１０の絞り開度に制御信号を伝達して、これらアクチュエータのどれかもしくはこれらの組合せを制御してやることにより潜熱および顕熱能力を調整して空調能力を発揮する。通常冷房運転時や通常暖房運転時におけるこれらアクチュエータの制御方法は、第２流量制御弁１０を全開として動作させない従来の空気調和機と同様である。
【００４９】
冷房回路での再熱除湿運転時の冷凍サイクルは図３に示した圧力−エンタルピ線図となり、再熱器となる第１室内熱交換器能力と蒸発器となる第２室内熱交換器の能力を調整し、潜熱および顕熱負荷を制御して空調能力を発揮する。潜熱能力の増減は、蒸発器となる第２室内熱交換器の能力の増減により調整を行う。一方蒸発器能力の増加により顕熱能力も増加するので、顕熱負荷以上の顕熱能力が発揮されてしまう場合は、再熱器となる第１室内熱交換器の能力を増加させる方に調整して加熱し、顕熱能力を調整する。この時の各アクチュエータの制御方法について、以下説明する。
【００５０】
例えば第１の例として、空気調和機運転時に温湿度偏差から第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報が室内ユニット１８内の信号線７３ａを経由して、第２の演算装置７４に伝達されて室内ファン６３の室内ファンモータ６４の回転数変化量が演算される。すなわち現状の室内ファン６３回転数の情報が、室内ファンモータ６４回転数制御装置６９より信号線７３ａを経由して第２の演算装置７４に伝達される。この時、検知した現状の室内の潜熱顕熱負荷に対して、リモコンなどの入力装置（図示せず）により入力された潜熱顕熱負荷の値を比較し、現状値に対して設定温湿度として入力された潜熱顕熱負荷の入力値が大きければ、室内ファンモータ６４回転数を現状より大きい値として演算し、新たな室内ファンモータ６４回転数の情報が信号線７３ａを経由して室内ファンモータ回転数制御装置６９に伝達され、新たな室内ファンモータ６４回転数として制御される。こうして室内ファン６３の送風量増加により潜熱顕熱能力が増加させ、現状値に対して入力値が一致するように制御する。
【００５１】
また例えば第２の例として、空気調和機運転時に温湿度偏差から第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報が信号線７３ａを経由して、第２の演算装置７４に伝達されて室外ファン６１の室外ファンモータ６２の回転数変化量が演算される。すなわち現状の室外ファン６２回転数の情報が、室外ファンモータ６２回転数制御装置６８より室外ユニット１７内の信号線７３ｃ、および室外ユニット１７と室内ユニット１８を結ぶ信号線７３ｂを経由して第２の演算装置７４に伝達されており、室内での再熱熱交換量を大きくしたい時ほど、室外ファンモータ６２回転数を現状より小さい値として演算し、新たな室外ファンモータ６２回転数の情報が信号線７３ｂ、７３ｃを経由して室外ファンモータ回転数制御装置６８に伝達され、新たな室外ファンモータ６２回転数として制御される。この時室外ファン６１の送風量低下により室外での凝縮能力が低下して、相対的に第１室内熱交換器２５での凝縮能力が増加し室内での再熱熱交換量が増加して、顕熱熱交換量を制御することができる。
【００５２】
また例えば第３の例として、空気調和機運転時に温湿度偏差から第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報が信号線７３ａを経由して、第２の演算装置７４に伝達されて圧縮機２１回転数の変化量が演算される。すなわち現状の圧縮機２１回転数の情報が、圧縮機回転数制御装置７０より信号線７３ｃ、７３ｂを経由して第２の演算装置７４に伝達されており、室内の潜熱顕熱熱交換量を大きくしたい時ほど、圧縮機２１回転数を現状より大きい値として演算し、新たな圧縮機２１回転数の情報が信号線７３ｂ、７３ｃを経由して圧縮機回転数制御装置７０に伝達され、新たな圧縮機２１回転数として制御される。この時図３に示す圧力−エンタルピ線図における冷凍サイクルでは、冷媒流量の増加により室内での潜熱顕熱熱交換量が増加する。
【００５３】
また例えば第４の例として、空気調和機運転時に温湿度偏差から第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報が信号線７３ａを経由して、第２の演算装置７４に伝達されて第１流量制御弁２４の弁開度変化量が演算される。すなわち現状の第１流量制御弁２４の弁開度情報が、第１流量制御弁２４弁開度制御装置７１より信号線７３ｃ、７３ｂを経由して第２の演算装置７４に伝達されており、室内での顕熱熱交換量を大きくしたい時ほど、第１流量制御弁２４の弁開度を現状より小さい値として演算し、新たな第１流量制御弁２４の弁開度の情報が信号線７３ｂ、７３ｃを経由して第１流量制御弁２４の弁開度制御装置７１に伝達され、新たな第１流量制御弁２４の弁開度として制御される。この時第１流量制御弁２４の弁開度の低下により、図３に示した点Ｃ、点Ｄ間の圧力が低下して第１室内熱交換器２５での凝縮温度が低下し再熱熱交換量が低下して、室内での顕熱熱交換量を調整する。
【００５４】
また例えば第５の例として、空気調和機運転時に温湿度偏差から第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報が信号線７３ａを経由して、第２の演算装置７４に伝達されて第２流量制御弁１０の弁開度変化量が演算される。すなわち現状の第２流量制御弁１０の弁開度情報が、第２流量制御弁１０弁開度制御装置７２より信号線７３ａを経由して第２の演算装置７４に伝達されており、室内での潜熱顕熱熱交換量を大きくしたい時ほど、第２流量制御弁１０の弁開度を現状より小さい値として演算し、新たな第２流量制御弁１０の弁開度の情報が信号線７３ａを経由して第２流量制御弁１０弁開度制御装置７２に伝達され、新たな第２流量制御弁１０の弁開度として制御される。この時第２流量制御弁１０の弁開度の低下により、図３に示した点Ｅ、点Ｆ間の圧力が低下して第２室内熱交換器２７での蒸発温度が低下して、室内での潜熱顕熱熱交換量を調整する。
【００５５】
なお、前述第１から第５の例として、５種類のアクチュエータ各々の制御方法について述べたが、これらアクチュエータは各種情報を基に個別に制御しても、５種類中の特定のアクチュエータを組み合わせて制御しても、５種類中の特定のアクチュエータ情報を基に別のアクチュエータを制御しても、それぞれのアクチュエータに優先度をつけて制御してもよい。例えば、室内ファン６３送風量が小さい状態で圧縮機２１の回転数を増加させると、潜熱顕熱熱交換量は増加するが蒸発温度が低下しすぎて０℃以下となり、ドレン水が凍結して室内ユニット１８を破損する恐れがある。この時は、室内ファン６３送風量に下限値を設け、この送風量に相当する室内ファンモータ６４回転数がある値以下の場合には圧縮機２１回転数に上限値を設け、この値の範囲で必要な潜熱顕熱熱交換量が得られない場合は、室内ファンモータ６４回転数を上昇させて室内ファン６３送風量を増加させ、蒸発温度が０℃以上となるよう制御してやればよい。また例えば潜熱顕熱熱交換量を制御装置６９および７２だけで制御する場合は、室内ユニット１８と室外ユニット１７の間で情報を伝達する必要がなくなり、室内ユニット１８と室外ユニット１７の間の信号線７３ｂは不要となって、信号線７３ｂの断線や結線不良による動作不良を防止することができる。また図６では、第２の演算装置７４を室内ユニット１８内に設置する例を示したが、室外ユニット１７内に設置しても良い。この時例えば、潜熱顕熱熱交換量を室外ファンの制御装置６８および圧縮機の制御装置７０および第２流量制御弁の制御装置７２だけで制御する場合は、第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報や、室内ファン６３の現状の回転数、および第２流量制御弁１０の弁開度の情報が、信号線７３ａ、７３ｂを経由して第２の演算装置７４に伝達されて、７３ｃを通って制御信号が伝達され制御装置６８および７０および７２が動作する。すなわち室外ユニット１７から室内ユニット１８への制御信号の戻りがないため、室内ユニット１８内のアクチュエータがどのような動作状況にあっても、例えば居住者が室内ファン６３の送風量を自由に選択しても、室内の潜熱顕熱能力を調整することができる。
【００５６】
以上に述べた制御方法により、温湿度偏差がゼロまたは所定の値以内となった場合には、現在の運転を続行すればよい。このようにこの実施の形態では、冷房回路での再熱除湿運転時の潜熱顕熱負荷に応じて、各種アクチュエータを制御することにより、部屋内の温湿度環境を居住者の好みに応じて最適な状態に制御することができ、なおかつ室内ユニット１８の構造を図２のように実施しているので、吹出し空気も温度ムラのない状態となり、快適な室内環境を得ることができる。合わせて第２流量制御弁１０に多孔質透過材を用いてやれば、冷媒流動音が低減し、より快適な室内環境が達成される。
【００５７】
一方暖房回路での再熱除湿運転時の冷凍サイクルは図４に示した圧力−エンタルピ線図となり、再熱器となる第２室内熱交換器２７の能力と蒸発器となる第１室内熱交換器２５の能力を調整し、潜熱および顕熱負荷を制御して空調能力を発揮する。潜熱能力の増減は、蒸発器となる第１室内熱交換器２５の能力の増減により調整を行う。一方蒸発器能力の増加により冷却する顕熱能力も増加するので、顕熱負荷以上の顕熱能力が発揮されてしまう場合は、再熱器となる第２室内熱交換器２７の能力を増加させる方に調整して加熱し、冷却する顕熱能力を調整する。第１室内熱交換器２５に設けられた温度センサー９２にて検知した蒸発温度が演算装置７８に伝達される。そして信号線から伝達された吸い込み空気温度センサー６５および湿度センサー６６にて検知された温度情報との比較を行い、蒸発温度が除湿できる温度以下となっているかを演算する。例えば蒸発温度が、吸い込み空気温度と湿度から演算した露点温度以下となっていればよい。この状態を実現するため、室内ファン６３の送風量、第２流量制御弁１０開度、圧縮機２１回転数が制御される。蒸発温度を下げて潜熱熱交換量を増加させたいときは、室内ファン６３の送風量低下、第２流量制御弁１０開度を絞る、圧縮機２１回転数能力を増加させる等の制御を行えばよい。この時の各アクチュエータの制御方法について、以下説明する。
【００５８】
例えば第１の例として、空気調和機運転時に温湿度偏差から第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報が室内ユニット１８内の信号線７３ａを経由して、第２の演算装置７４に伝達されて室内ファン６３の室内ファンモータ６４の回転数変化量が演算される。すなわち現状の室内ファン６３回転数の情報が、室内ファンモータ６４回転数制御装置６９より信号線７３ａを経由して第２の演算装置７４に伝達される。この時、検知した現状の室内の潜熱顕熱負荷に対して、リモコンなどの入力装置（図示せず）により入力された潜熱顕熱負荷の値を比較し、現状値に対して入力値が大きければ、室内ファンモータ６４回転数を現状より大きい値として演算し、新たな室内ファンモータ６４回転数の情報が信号線７３ａを経由して室内ファンモータ回転数制御装置６９に伝達され、新たな室内ファンモータ６４回転数として制御される。こうして室内ファン６３の送風量増加により潜熱顕熱能力が増加する。
【００５９】
また例えば第２の例として、空気調和機運転時に温湿度偏差から第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報が信号線７３ａを経由して、第２の演算装置７４に伝達されて圧縮機２１回転数の変化量が演算される。すなわち現状の圧縮機２１回転数の情報が、圧縮機回転数制御装置７０より信号線７３ｃ、７３ｂを経由して第２の演算装置７４に伝達されており、室内の潜熱顕熱熱交換量を大きくしたい時ほど、圧縮機２１回転数を現状より大きい値として演算し、新たな圧縮機２１回転数の情報が信号線７３ｂ、７３ｃを経由して圧縮機回転数制御装置７０に伝達され、新たな圧縮機２１回転数として制御される。この時図４に示す圧力−エンタルピ線図における冷凍サイクルでは、冷媒流量の増加により室内での潜熱顕熱熱交換量が増加する。
【００６０】
また例えば第３の例として、空気調和機運転時に温湿度偏差から第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報が信号線７３ａを経由して、第２の演算装置７４に伝達されて第２流量制御弁１０の弁開度変化量が演算される。すなわち現状の第２流量制御弁１０の弁開度情報が、第２流量制御弁１０弁開度制御装置７２より信号線７３ａを経由して第２の演算装置７４に伝達されており、室内での潜熱顕熱熱交換量を大きくしたい時ほど、第２流量制御弁１０の弁開度を現状より小さい値として演算し、新たな第２流量制御弁１０の弁開度の情報が信号線７３ａを経由して第２流量制御弁１０弁開度制御装置７２に伝達され、新たな第２流量制御弁１０の弁開度として制御される。この時第２流量制御弁１０の弁開度の低下により、図４に示したＤ点の圧力が低下して第１室内熱交換器２５での蒸発温度が低下して、室内での潜熱顕熱熱交換量を調整する。
【００６１】
なお、前述第１から第３の例として、３種類のアクチュエータ各々の制御方法について述べたが、これらアクチュエータは各種情報を基に個別に制御しても、特定のアクチュエータを組み合わせて制御しても、３種類中の特定のアクチュエータ情報を基に別のアクチュエータを制御しても、それぞれのアクチュエータに優先度をつけて制御してもよい。例えば、室内ファン６３送風量が小さい状態で圧縮機２１の回転数を増加させると、潜熱顕熱熱交換量は増加するが蒸発温度が低下しすぎて０℃以下となり、ドレン水が凍結して室内ユニット１８を破損する恐れがある。この時は、室内ファン６３送風量に下限値を設け、この送風量に相当する室内ファンモータ６４回転数がある値以下の場合には圧縮機２１回転数に上限値を設け、この値の範囲で必要な潜熱顕熱熱交換量が得られない場合は、室内ファンモータ６４回転数を上昇させて室内ファン６３送風量を増加させ、蒸発温度が０℃以上となるよう制御してやればよい。また例えば潜熱顕熱熱交換量を制御装置６９および７２だけで制御する場合は、室内ユニット１８と室外ユニット１７の間で情報を伝達する必要がなくなり、室内ユニット１８と室外ユニット１７の間の信号線７３ｂは不要となって、信号線７３ｂの断線や結線不良による動作不良を防止することができる。また図６では、第２の演算装置７４を室内ユニット１８内に設置する例を示したが、室外ユニット１７内に設置しても良い。この時例えば、潜熱顕熱熱交換量を制御装置６８および７０および７２だけで制御する場合は、第１の演算装置６７にて推算された室内の潜熱顕熱負荷の情報や、室内ファン６３の現状の回転数、および第２流量制御弁１０の弁開度の情報が、信号線７３ａ、７３ｂを経由して第２の演算装置７４に伝達されて、７３ｃを通って制御信号が伝達され制御装置６８および７０および７２が動作する。すなわち室外ユニット１７から室内ユニット１８への制御信号の戻りがないため、室内ユニット１８内のアクチュエータがどのような動作状況にあっても（例えば居住者が室内ファン６３の送風量を自由に選択しても）、室内の潜熱顕熱能力を調整することができる。
【００６２】
以上に述べた制御方法により、温湿度偏差がゼロまたは所定の値以内となった場合には、現在の運転を続行すればよい。このようにこの実施の形態では、暖房回路での再熱除湿運転時の潜熱顕熱負荷に応じて、各種アクチュエータを制御することにより、部屋内の温湿度環境を居住者の好みに応じて最適な状態に制御することができ、なおかつ室内ユニット１８の構造を図２のように実施しているので、吹出し空気も温度ムラのない状態となり、快適な室内環境を得ることができる。合わせて第２流量制御弁１０に多孔質透過材を用いてやれば、冷媒流動音が低減し、より快適な室内環境が達成される。
【００６３】
なお以上において暖房回路における再熱除湿運転時の顕熱負荷は、冷却する場合を例に説明したが、加熱する場合の顕熱負荷については第２室内熱交換器２７での熱交換量増減を前述した制御方法にて実現すればよい。能力制御範囲と運転切り換えの動作マップを図７に示す。暖房運転では、潜熱能力は０であり、加熱する顕熱能力を制御することができる。冷房運転は、前述した潜熱顕熱負荷検知装置にて検知した潜熱顕熱負荷が、冷房運転で設定した潜熱顕熱能力制御範囲に相当するときに開始する。この時冷却する顕熱負荷と潜熱負荷は、他の運転と比較して大きい場合となる。そして冷房運転を持続し、前述した潜熱顕熱負荷検知装置にて検知した潜熱顕熱負荷が冷房運転で設定した潜熱顕熱能力制御範囲を越えて小さくなり、あらかじめ設定した範囲になった時、運転を冷房回路での再熱除湿運転に切り換える。そして潜熱顕熱負荷がさらに小さくなりあらかじめ設定した範囲に達した時、運転を暖房回路での再熱除湿運転に切り換える。
【００６４】
以上、冷房運転からの運転切り換え方法について説明したが、空調機が運転を開始するときに潜熱顕熱負荷検知装置にて検知した潜熱顕熱負荷に応じて、最初の運転方法を決定し、その後の潜熱及び顕熱の負荷変動を検知して、図７のようなあらかじめ設定した潜熱顕熱能力制御範囲のマップから、適切な運転方法を選択し負荷変動の状況に応じて範囲を切り替えるときに四方弁などを自動的に切り替えていく。この切替は自由に切替できるし，一旦圧縮機を停止してから切り替えても良い。切替動作時に大きな音がする場合は圧縮機を停止して切りかえるが，後で述べる発泡金属などを使用した制御弁を使用すれば音の発生を押さえられるので停止させずにそのまま切りかえられる。
【００６５】
また暖房回路での再熱除湿運転は、潜熱能力を確保しつつ、加熱する顕熱能力を発揮することができるため、例えば外気温が低いが相対湿度が高い空調条件において除湿することができる。すなわち降雪時や冬季の降雨時など、絶対湿度は大きくないものの相対湿度が高い空調条件において除湿することができるため、窓などへの結露を防止することができ、窓の結露水が垂れて壁を濡らしてしまうような不快な現象を回避することができる。
【００６６】
以上により、冷房運転での能力制御範囲、冷房回路での再熱除湿運転制御範囲、暖房回路での再熱除湿運転制御範囲、暖房での能力制御範囲を組み合わせることにより、冷却、加熱を含むより広範囲な潜熱顕熱能力制御範囲を達成することができる。
【００６７】
一方冷房気液分離容器使用運転時の冷凍サイクルは図５に示した圧力−エンタルピ線図となる。この時の各アクチュエータの制御方法について、特に冷媒としてＲ３２を用いた場合について、以下説明する。
【００６８】
Ｒ３２冷媒は、例えばＲ４１０Ａ冷媒と比較して圧縮機吐出温度が１０℃以上も高くなり、圧縮機内の冷凍機油の劣化が早く、圧縮機摺動部の潤滑不良など、信頼性上問題点があり、必要以上に圧縮機吐出温度が上昇しないようにアクチュエータを制御する必要がある。本発明では、図６のごとく圧縮機吐出に設けられた温度センサー９３にて検知した吐出温度が演算装置７９に伝達される。また第２室内熱交換器２７に設けられたセンサー９１にて検知した蒸発熱交換器出口過熱度が演算装置７７に伝達される。センサー９１は例えば蒸発熱交換器出口温度と蒸発熱交換器出口圧力から演算されたり，蒸発熱交換器中間温度と蒸発熱交換器出口温度の差の温度から演算できる。蒸発器の熱交換器効率を最大限に発揮させるためには、蒸発熱交換器出口過熱度を０から３℃程度に制御する必要がある。このためには、検知した蒸発熱交換器出口過熱度がその値の範囲になるよう、圧縮機２１回転数、第１流量制御弁２４の開度、室内ファン６３の送風量、室外ファン６１の送風量を制御してやればよい。
【００６９】
しかし蒸発熱交換器出口過熱度を０から３℃程度に制御すると、圧縮機吸入では確実に吸入過熱度がこの値（３℃）より上昇し、圧縮機吐出温度が必要以上に高くなる恐れがある。そこで室内の吸い込み空気温度センサー６５、演算装置９５を介した外気温センサー９４、圧縮機２１回転数、第１流量制御弁２４の開度、室内ファン６３の送風量、室外ファン６１の送風量の情報を基に演算装置７４で演算した圧縮機吐出温度の上限値に対して、圧縮機吐出温度センサー９３の値がこれを越えた場合は、演算制御装置７６を介して第３流量制御弁８１の開度を調節し、気液分離容器８２から、飽和ガス、もしくは気液二相冷媒をガスバイパス回路８０を通して冷媒回路上のＧ点に注入してやればよい。このように第３流量制御弁８１の開度を圧縮機吐出冷媒温度，圧縮機吸入冷媒過熱度，圧縮機吐出冷媒過熱度に相当する値を目標に調整する。これにより、蒸発器の熱交換器効率が最大となる蒸発熱交換器出口過熱度を保持したまま、圧縮機吐出温度を低下させることができ、空気調和機のエネルギ効率を高い値としながら、信頼性の向上も図ることができる。なお室内熱交換器出口冷媒過熱度は、これに相当する値を検知すればよい。例えば、室内熱交換器出口温度と室内熱交換器出口圧力を測定して冷媒過熱度を演算しても良いし、室内熱交換器中間温度と室内熱交換器出口温度とから推算しても良い。また圧縮機吐出冷媒温度も、これに相当する値を検知すればよい。例えば圧縮機吸入冷媒温度や圧縮機吸入冷媒過熱度、圧縮機吐出冷媒過熱度、などから推算すればよい。
【００７０】
本発明の第１の実施形態として以上述べたような構造のほかに、室内熱交換器を円弧状に配置したり、図２よりさらに多数に分割した多段曲げ構造とし、再熱器と蒸発器の間を熱的に遮断する、例えば伝熱管１１の段間の伝熱フィン２８に切り込みを入れフィンでの熱伝導を防止する等の工夫をすれば、本発明の目的はさらに容易に達成される。
【００７１】
本発明の第１の実施形態によるさらに他の実施例としては、図８に示すように、冷房回路での再熱除湿運転の際、再熱器となる熱交換器の冷媒流れ上流側に熱的に遮断された補助熱交換器１４を備えてもよい。この補助熱交換器１４は、冷房回路での再熱除湿運転の際には再熱器として働くため、再熱熱交換器容量が拡大して再熱熱交換量が増加し、室温低下を防ぎながら再熱除湿する能力制御範囲を大きくすることが可能となる。また、単に再熱熱交換器容量を拡大すると室内ユニット１８寸法が大きくなるが、本実施例のように設置すれば、室内ユニット１８内の空隙スペースを有効に活用することができ、室内ユニット１８のコンパクト化も可能となる。
【００７２】
次に補助熱交換器１４を設けた例を図８で説明する。図８において、暖房運転時室内熱交換器は凝縮器となるが、補助熱交換器１４は室内熱交換器の下流側に設置される。凝縮熱交換量を向上させるためには凝縮器出口での冷媒過冷却度を十分にとり、冷媒エンタルピを拡大する必要がある。しかし、過冷却域では冷媒は液状態であるとともに、冷媒温度も凝縮温度より低い。このため、過冷却域では伝熱管内の冷媒流速を上げて冷媒熱伝達率を高めるとともに、過冷却域での伝熱管を空気流れの風上側に設置して、熱交換前の比較的温度の低い空気と熱交換させて、凝縮熱交換量向上を図る必要がある。また過冷却部分を飽和部分と熱的に遮断してやることにより、伝熱フィンを熱伝導して熱交換してしまう空調に寄与しない熱量を減らす必要がある。またさらには、凝縮器入口の高温ガス冷媒域での伝熱管配置を空気と対向流としてやる必要がある。図８において、補助熱交換器１４は、暖房運転時凝縮器の出口側となる部分に設置し、かつ前面上段斜め部分１熱交換器の空気流れ上流側に設置されており、冷媒流路を一系統としている。従って前述したように、伝熱管内の冷媒流速が十分に早くなり冷媒熱伝達率が高くなり、空気との温度差も十分に取れて、過冷却熱交換器として十分な性能を発揮することができる。また、補助熱交換器１４を前面上段斜め部分１熱交換器とは別体とし熱的に遮断して設置したので、伝熱フィン２８間を熱伝導して熱交換してしまう空調に寄与しない熱量を減らすことができ、熱交換性能を向上させることができる。またさらには、図８においては暖房運転時凝縮器入口となる高温ガス冷媒が流れる配管を空気流れの下流側に設置し、温度が低い空気と対向して流れているので、熱交換性能をより向上させることができる。
【００７３】
なお、図８では過冷却熱交換器となる補助熱交換器１４の冷媒流路が一系統で、凝縮器入口となる高温ガス冷媒での冷媒流路が二系統の場合を示したが、流路数は冷房運転も含めた冷媒熱伝達率と冷媒圧力損失を鑑み、熱交換性能に与える効果が最大となるよう最適値に設定されるべきであり、主として伝熱管径に応じて流路数は設定される。すなわち補助熱交換器１４の伝熱管径を主たる室内熱交換器の伝熱管径より小さくしてやれば、伝熱管内の冷媒流速が十分に早くなって冷媒熱伝達率が高くなり、さらに熱交換量を向上させることができる。
【００７４】
またこの例の冷房気液分離容器使用時の動作について説明する。冷房運転時、補助熱交換器１４には液冷媒が流入する。気液分離容器がない、従来の冷媒回路では補助熱交換器１４には気液二相冷媒が流入する。液冷媒は気液二相冷媒より熱伝達率が低いため、熱交換量が低下する恐れがある。本実施例ではこの欠点を解決するために、補助熱交換器１４の冷媒流路を一系統とすることにより、伝熱管内の冷媒流速を上げて冷媒熱伝達率を高めてやることが出来、蒸発熱交換量向上が達成されている。なお、冷媒流路を一系統とすることにより冷媒圧力損失の増加が懸念されるが、補助熱交換器１４を流れる冷媒は乾き度が低いため、液単相とほぼ同等の圧力損失となり、過大な圧力損失増加はない。
【００７５】
また本実施例では、通過風速が一番大きい前面上段斜め部分１熱交換器の空気流れ９ａ上流側に補助熱交換器１４を配置したが、通風抵抗は増加し風量が低下する恐れがあるので、補助熱交換器１４は通風抵抗が小さい物にする必要がある。すなわち、伝熱フィンのフィンピッチを拡大したり、伝熱フィン幅を小さくしたり、あるいは室内熱交換器に伝熱性能を向上させるために設けている伝熱フィン切り起こしを行わない仕様にしたりしてもよい。
【００７６】
なお補助熱交換器１４を設置するスペースがどうしても得られない場合は、図９に示すように、暖房時出口流路を１系統とし、前面上段斜め部分１熱交換器の前列側伝熱管と後列側伝熱管の伝熱フィン２８の間に、これら伝熱管を熱的に遮断する切り込み２０を入れてもよい。これにより伝熱フィンを熱伝導して熱交換してしまう空調に寄与しない熱量を減らすことができ、熱交換量を向上させることができる。また暖房時出口流路を１系統とし、伝熱管径を主たる室内熱交換器の伝熱管径より小さくしてやれば、伝熱管内の冷媒流速が十分に早くなって冷媒熱伝達率が高くなり、さらに熱交換量を向上させることができる。
【００７７】
本発明の空気調和機において、室内ユニット１８に配置される第２流量制御弁１０に、図１０に示した構造の流量制御弁を用いた場合の特徴を以下に説明する。この流量制御弁の構造、動作は以下の通りである。
【００７８】
図１０において、第２流量制御弁１０における３１が第１流路で第１室内熱交換器２５に接続され、３２が第２流路で第２室内熱交換器２７に接続されている。３３は冷媒流路が開口する主弁座、３４は第２流量制御弁１０本体の内面に沿って上下に摺動する主弁体で、これら主弁座３３と主弁体３４で絞り部を構成している。３５は主弁体３４を駆動する電磁コイルで、制御部（図示無し）からの指令に基づいて、電磁コイル３５を通電遮電し、主弁体３４を開閉する。主弁体３４は冷媒流れ方向に連通する多孔質透過材により形成され、具体的には金属粉やセラミック粉、発泡金属および発泡樹脂などを型に入れて加圧成形し、溶融点以下の温度で焼き固めた物で構成されている。電磁コイル３５に通電すると、主弁体３４は上昇し、主弁座３３から離れ、第１流路３１と第２流路３２が流動抵抗なく冷媒が流動する。また再び電磁コイル３５に通電すると、主弁体３４は下降し、主弁座３３と密着し、主弁体３４を構成する多孔質透過材を介して、第１流路３１と第２流路３２が連通する。
【００７９】
次に、図１０に示した流量制御弁を用いた空気調和機の動作について説明する。通常冷房運転時は図１の実線の矢印に示す方向に、通常暖房運転時は図１の点線の矢印に示す方向に、冷媒が流れる。この時、第１流量制御弁２４により、冷凍サイクルの流量が調整され、第２流量制御弁１０は図１０（ａ）に示すように、主弁体３４は上昇して主弁座３３から離れ、第１流路３１と第２流路３２が連通し、流動抵抗なく冷媒が流動する。従って、冷媒圧力損失増加による能力の低下や効率の低下がなく、空気調和機を動作させることができる。
【００８０】
一方冷房回路での再熱除湿運転時は、第１流量制御弁２４の開度を開き気味とし、第２流量制御弁１０を主たる減圧装置として使用する冷凍サイクルとなる。この冷房回路での再熱除湿運転時の冷凍サイクルにおける、圧力−エンタルピ線図は図３となる。すなわち、第２流量制御弁１０は図１０（ｂ）に示すように、主弁体３４が下降して主弁座３３と密着し、主弁体３４を構成する多孔質透過材を介して第１流路３１と第２流路３２が連通し、多孔質透過材が流動抵抗体として作用する。
【００８１】
このとき、第２流量制御弁１０の流動抵抗体として多孔質透過材を用いているので、第２流量制御弁１０を気液二相冷媒もしくは液冷媒が通過する際の冷媒流動音を大幅に低減することができる。例えば図１９に示す従来の第２流量制御弁１０は、図１９に示すように主弁座３３と主弁体３４の隙間のオリィフィスを流動抵抗体として作用させているので、気液二相流が通過する際に非常に大きな冷媒流動音が発生する。特に図３に示すように、第２流量制御弁１０の入口がＤ点のように冷媒乾き度が小さく気液二相冷媒の流動様式がスラグ流となる場合に、大きな冷媒流動音になることが知られている。この冷媒流動音の発生原因としては、流れ方向に対して蒸気冷媒が断続的に流れ、オリィフィス部をそのオリィフィス径より大きな蒸気スラグもしくは蒸気気泡が通過する際に、蒸気スラグもしくは蒸気気泡が崩壊することにより振動が発生し、図１９における主弁座３３等を伝搬して音が発生したり、オリィフィス部を速度が異なる蒸気冷媒と液冷媒が交互に通過するため、それに伴って圧力変動が生じ、主弁座３３等を伝搬して音が発生するためである。
【００８２】
これに対して、図１０（ｂ）に示した本実施例における第２流量制御弁１０では、気液二相冷媒や液冷媒は多孔質透過材で構成されている主弁体３４の微細で無数の通気孔を通過し減圧される。そのため、蒸気スラグや蒸気泡が崩壊することは無い。また、蒸気冷媒と液冷媒が同時に絞り部を通過するため非常によく混合し冷媒の速度変動が生じず、圧力も変動しない。図１９に示した従来の第２流量制御弁１０では流路が１ヶ所であるが、多孔質透過材では内部の流路が複雑に構成され、この小孔が流動抵抗体となり、この内部で圧力が低下する。多孔質透過材はその内部において流速変動は圧力変動として繰り返され一部熱エネルギに変換しながら圧力変動を一定にする効果がある。これを一般に吸音効果と言い、音を消すメカニズムと考えられる。また、多孔質透過材内部で冷媒の流速が十分に減速され、一定となるため、多孔質透過材出口部で流れに渦が発生することも無く噴流騒音も小さくなる効果がある。このため第２流量制御弁１０から発生する冷媒流動音を大幅に低減することができる。
【００８３】
なお、再熱除湿運転時の第２流量制御弁１０の流量特性（冷媒流量と冷媒圧力損失の関係）は、主弁体３４に用いる多孔質透過材の大きさや冷媒が通過する流路長さおよび多孔質透過材の空隙率（単位体積あたりの隙間容積）を調整することによって、調整することができる。すなわちある冷媒流量を小さな圧力損失で流す場合は、多孔質透過材の孔径を大きくしたり（例えば、多孔質透過材の素子を大きくするなど）、流路長さを短くしたり（弁本体を短くするなど）、空隙率が大きい多孔質透過材を用いれば良い。また、逆にある冷媒流量を大きな圧力損失で流す場合は多孔質透過材の孔径を小さくしたり（例えば、多孔質透過材の素子を小さくするなど）、流路長さを長くしたり（弁本体を長くするなど）、空隙率が小さい多孔質透過材を用いれば良い。このような主弁体３４に用いる多孔質透過材の孔径や弁本体の形状は、空気調和機設計時に最適に設計される。
【００８４】
これにより、従来空気調和機で必要であった、第２流量制御弁１０の回りに遮音材や制振材を周囲に巻きつけるなどの対策も不要でコスト低減となり、さらにこれら他材質が不要となるため、空気調和機のリサイクル性も向上する。
【００８５】
なお、以上冷房回路での再熱除湿運転時の動作について述べたが、冷媒流れ方向が逆となる暖房回路での除湿運転時（図４に示した冷凍サイクル運転状態）においても、同様の効果が得られる。
【００８６】
また、上述した多孔質透過材を用いた流量制御弁は、第１流量制御弁２４に用いても、冷媒流動音を低減するなどの同様の効果が得られる。開度調整を行う制御弁においても主体弁３４と主弁座３３の隙間調整により流量制御が可能である。また上述した気液二相冷媒に起因する冷媒流動音の発生に対しては、空気調和機に限定されることなく、冷蔵庫などを含めた冷熱空調機器の冷凍サイクル一般についての課題であり、本実施の形態に示した流量制御弁は、このような冷凍サイクル一般に広く適用することで、冷媒流動音を低減するなどの同様の効果が得られる。
【００８７】
実施の形態２．
本発明の第２の実施形態による空気調和機について説明する。図１１は、本発明の冷媒回路で、図１と同一の部位には、同一の番号を付けている。室内ユニット１８の構造は例えば図２である。実施の形態１で説明した各運転モードは同様に行うことが出来る。この時室内ユニット１８に配置される第１室内熱交換器２５と第２室内熱交換器２７の間の第２流量制御弁位置の配管に、多孔質透過材を用いた絞り装置３６を設け、これと並列に絞り装置３６をバイパスする冷媒流路上に電磁開閉弁３７を設けている。すなわち絞り装置３６と電磁開閉弁３７により図１における第２流量制御弁１０の役割を果たしている。この絞り装置３６の構造の一例を図１２に示す。絞り装置３６本体は円筒状の容器で構成され、図１０で示した多孔質透過材の一例である発泡金属３８ａ、３８ｂがオリィフィス３９を挟み込む構造としている。多孔質透過材の他の例としては、金属粉やセラミック粉、焼結金属および発泡樹脂などを型に入れて加圧成形し、溶融点以下の温度で焼き固めた物であればよい。そして発泡金属３８ａ、３８ｂの両端は、固定治具４０で固定され、配管４１が接続されている。以下、この絞り装置３６と電磁開閉弁３７の動作について説明する。
【００８８】
この実施の形態において、再熱除湿運転以外では、図１（ｂ）のごとく電磁開閉弁３７を開状態とし、冷媒流路を構成する。この時、絞り装置３６の流動抵抗に対して電磁開閉弁３７の流動抵抗が小さいので、冷媒は絞り装置３６をバイパスしてほとんど抵抗が無い状態で電磁開閉弁３７を流れる。従って、冷媒圧力損失増加による能力の低下や効率の低下がなく、空気調和機を動作させることができる。一方再熱除湿運転時は、電磁開閉弁３７を閉状態とし、冷媒はオリィフィス３９を通って減圧される。この時、図１２における実線の矢印方向に流入した気液二相冷媒は発泡金属３８を通過する。この時発泡金属３８ａは、オリィフィス３９に流入する気液二相冷媒を均一に混合し、発泡金属３８ｂはオリィフィス３９から流出した気液二相冷媒を均一に混合する作用を示すので、冷媒流動音の発生を防止することができる。
【００８９】
なお、図１２においては、絞り装置３６の発泡金属３８がオリィフィス３９を挟み込む構造としたが、オリィフィス３９は、発泡金属３８のみでは流動抵抗が小さく、所定の減圧作用が得られ場合に併用すればよい物であり、多孔質透過材の大きさや冷媒が通過する流路長さおよび多孔質透過材の空隙率（単位体積あたりの隙間容積）を調整することによって、流動抵抗を調整することができれば、発泡金属３８単独で流動抵抗として用いても良い。また、オリィフィス３９を併用する場合、燒結金属３８はオリィフィス３９の冷媒流れ上流側３８ａ、もしくは冷媒流れ下流側３８ｂのみの配置としても、通過する気液二相流は非常によく混合されるので、冷媒流動音の発生を防止することができる。なお、実際冷媒回路中にはスラッジと呼ばれる微小流体（ゴミ、劣化物など）が流動するので、発泡金属３８の多孔質透過材の空隙率が小さすぎるとこれらスラッジが堆積し、発泡金属３８に冷媒が流れなくなる恐れがある。そこで実際の設計としては、発泡金属３８の多孔質透過材の空隙率はスラッジが堆積せず、かつ気液二相流が非常によく混合されるよう、発泡金属３８の流路断面積、厚さと空隙率を調整し、この発泡金属３８の流動抵抗で確保できない所定の減圧量をオリィフィス３９にて減圧する手段がとられる。またオリィフィス３９と発泡金属３８に間隔を設けることにより、気液二相流がよりよく混合される。またオリィフィス３９と発泡金属３８ａの間隔と、オリィフィス３９と発泡金属３８ｂの間隔は同一としても良いが、図１２に示すように下流側の間隔を大きくした方がより冷媒流動音低下の効果が得られる。また図１２は、図１０のように主弁体３４に用いた多孔質透過材を用いた流量制御弁より非常に安価となり、加えて電磁開閉弁３７は従来から用いられている二方弁を流用できるので、絞り装置３６と電磁開閉弁３７を併用しても、図１の第２流量制御弁１０より、安価にすることができる。
【００９０】
なお図１１に示す冷媒回路にて、冷房回路と暖房回路の両方で再熱除湿運転を動作させるためには、冷媒流れ方向が絞り装置３６、電磁開閉弁３７で逆となる。従って電磁開閉弁３７は、双方流れにて冷媒が封止できる構造の弁とすれば、この機能を達成できる。
【００９１】
実施の形態３．
本発明の第３の実施形態による空気調和機について説明する。図１３は、本発明の冷媒回路で、図１と同一の部位には、同一の番号を付けている。室内ユニットの構造は例えば図２である。実施の形態１で説明した各運転モードは同様に行うことが出来る。この時室外ユニット１７の第１流量制御弁２４と気液分離容器８２回りに逆止弁８３ａ、８３ｂ、８３ｃ、８３ｄを用いた冷媒回路を形成している。以下、この冷媒回路の動作について説明する。
【００９２】
この実施の形態において、冷房運転時の冷媒流れ方向は実線の矢印であり、Ｂ点を通った冷媒は、逆止弁８３ａを通って第１流量制御弁２４により減圧され、気液分離容器８２により気液分離され、液冷媒は逆止弁８３ｂを通ってＣ点に至る。一方、暖房運転時の冷媒流れ方向は点線の矢印であり、Ｃ点を通った冷媒は、逆止弁８３ｃを通って第１流量制御弁２４により減圧され、気液分離容器８２により気液分離され、液冷媒は逆止弁８３ｄを通ってＢ点に至る。以上により図１３に示した冷媒回路では冷房、暖房運転とも気液分離冷凍サイクルを自動的に構成することができ、冷房、暖房とも冷媒圧力損失を低減して、効率の高い運転を達成することができる。
【００９３】
実施の形態４．
本発明の第４の実施形態による空気調和機について説明する。図１４は、本発明の冷媒回路で、図１と同一の部位には、同一の番号を付けている。室内ユニット１８の構造は例えば図２である。実施の形態１で説明した各運転モードは同様に行うことが出来る。この時室外ユニット１７の圧縮機吸入にアキュムレータ８４を設け、ガスバイパス回路８０をアキュムレータ８４上流に設置している。以下、この冷媒回路の動作について説明する。
【００９４】
第３流量制御弁８１を開けて運転する場合（暖房回路での再熱除湿運転、気液分離冷凍サイクルでの運転、暖房除霜運転など）において、流量制御が実際の流れに追いつかず、ガスバイパス回路８０に液冷媒が流れてしまう場合がある。この時、アキュムレータ８４が設けられ、なおかつガスバイパス回路８０がアキュムレータ８４上流側に接続されているので、アキュムレータ８４で気液分離がなされ液冷媒が貯留される。従って必要以上に圧縮機吸入に液冷媒が戻らず、液圧縮状態を回避することができ、圧縮機の信頼性を向上させることができる。また、余剰冷媒がアキュムレータ８４に貯留されるので、冷凍サイクルが最適冷媒量で運転され、効率を向上させることができる。
【００９５】
なお以上の実施形態１から４に述べた空調機に用いる気液分離容器８２の構造例を図１５、図１６に示す。図１５（ａ）は二相冷媒流入管が上方から入る例、図１５（ｂ）は二相冷媒流入管が水平方向から入る例、図１５（ｃ）は二相冷媒流入管が水平方向から入り、容器内で旋回流を起こして気液分離効率を向上させる例、図１５（ｄ）は冷房回路、暖房回路でも気液分離を行う例を示す。また図１６（ａ）は、二相冷媒流入管を気液分離容器内の中間程度まで延長し、この管の横方向に穴を開けて、冷媒流れを容器内壁に衝突させる例、また図１６（ｂ）は、二相冷媒流入管を気液分離容器内の中間程度まで延長し、この管を横方向に曲げて、冷媒流れを容器内壁に衝突させ、かつ旋回流を起こす例で、この管を曲げるため容器を２分割で製作するようにしている。図１５、図１６のいずれの例においても所定の気液分離効率が得られるように、流入する冷媒流速や容器容積を設計すればよい。また気液分離容器は、冷房運転、暖房運転、冷房回路での再熱除湿運転、暖房回路での再熱除湿運転、暖房除霜運転など、各運転モードにおける余剰冷媒を貯留し、これら運転時の冷媒過多による効率低下や、余剰冷媒が圧縮機に流入して液バック運転による圧縮機故障を防ぐことができる。なお、気液分離容器の容積は、あらかじめ各運転モードにおける最適冷媒量を試験や計算によって求め、その最大冷媒量と最小冷媒量の差が貯留できる内容積として決定すればよい。
【００９６】
なお以上の実施形態１から４に述べた空調機に用いる冷媒としてＲ４１０ＡもしくはＲ３２もしくはＲ２９０を使用した場合の特徴について説明する。従来空気調和機に用いられていたＲ２２冷媒に対して、Ｒ４１０ＡやＲ３２やＲ２９０冷媒はオゾン破壊係数が０であり、とくにＲ３２やＲ２９０は地球温暖化係数もＲ２２やＲ４１０Ａより小さく、地球環境に優しい冷媒という特徴がある。加えて、Ｒ４１０ＡやＲ３２やＲ２９０はＲ２２と比較して冷媒圧力損失が小さいという特性を持つ。Ｒ４１０Ａ、Ｒ２９０はＲ２２と比較して冷媒圧力損失が７０％、Ｒ３２はＲ２２と比較して冷媒圧力損失が５０％となる。従って、Ｒ４１０ＡやＲ３２やＲ２９０では蒸発器入口温度と出口温度の温度勾配が小さくなり、蒸発器温度が均一化されるという特性を持つ。従って蒸発器を出て冷却除湿された空気には温度ムラがなく、加熱された空気と非常によく混合することになり、温度低下がなく除湿された空気が、温度ムラがなく吹き出されるため、非常に快適な室内環境を作ることができるという、本実施例の目的により合致した冷媒であると言える。
【００９７】
また、補助熱交換器１４を設置し、冷媒流路を一系統で構成した例を示したが、Ｒ４１０ＡやＲ３２やＲ２９０はＲ２２と比較して冷媒圧力損失が小さいという特性を持つため、冷媒流速向上による冷媒管内熱伝達率向上効果が大きく、各種運転モードにおいても熱交換能力の向上を図ることができる。通常図２のように蒸発器を前面下部と背面のように分散させたり、補助熱交換器を設けたり第２流量制御弁１０を設ける等、複雑な構成にすると配管引き回しのために熱ロスが発生するが、上記Ｒ４１０ＡやＲ３２やＲ２９０のように冷媒圧力損失が小さい冷媒を用いれば、熱ロスの少ない状態で快適な空調環境を提供することが可能になる。
【００９８】
また冷媒としては、ＨＦＣ系（Ｒ１１６、Ｒ１２５、Ｒ１３４ａ、Ｒ１４、Ｒ１４３ａ、Ｒ１５２ａ、Ｒ２２７ｅａ、Ｒ２３、Ｒ２３６ｅａ、Ｒ２３６ｆａ、Ｒ２４５ｃａ、Ｒ２４５ｆａ、Ｒ３２、Ｒ４１、ＲＣ３１８などや、これら冷媒の数種の混合冷媒Ｒ４０７Ａ、Ｒ４０７Ｂ、Ｒ４０７Ｃ、Ｒ４０７Ｄ、Ｒ４０７Ｅ、Ｒ４１０Ｂ、Ｒ４０４Ａ、Ｒ５０７Ａ、Ｒ５０８Ａ、Ｒ５０８Ｂなど）、ＨＣ系（ブタン、イソブタン、エタン、プロパン、プロピレンなどや、これら冷媒の数種の混合冷媒）、自然冷媒（空気、炭酸ガス、アンモニアなどや、これら冷媒の数種の混合冷媒）、またこれらＨＦＣ系、ＨＣ系、自然冷媒などの数種の混合冷媒など、どんな冷媒を用いてもオゾン破壊係数が０であり、以上の実施形態に述べた再熱除湿運転時の効果は発揮される。
【００９９】
以上、本発明の実施形態１から４による再熱器となる第１室内熱交換器２５の熱交換器と蒸発器となる第２室内熱交換器２７の熱交換器の伝熱管形状は円管で例えば外径１０ｍｍ以下であるが、円管と断面積が同等である楕円伝熱管や扁平伝熱管であってもその効果は達成される。また、例えば再熱器では伝熱フィン２８に多くの切り起こしを設け空気との伝熱促進を図り、蒸発器では切り起こしの数を少なくして露だれ性を向上させるというように、再熱器となる第１室内熱交換器２５の熱交換器と蒸発器となる第２室内熱交換器２７とで伝熱フィン２８の切り起こし形状やフィンピッチを変えてもよい。また、多段曲げ熱交換器の各部分においても、伝熱フィン２８の切り起こし形状やフィンピッチを変えてもよい。また１列目熱交換器と２列目熱交換器とで伝熱フィン２８の切り起こし形状やフィンピッチを変えてもよい。加えて多段曲げ熱交換器の各部分において、列数を変更してもよい。例えば背面熱交換器３を１列熱交換器として構成してコスト低減を図ってもよい。
【０１００】
なお、上記実施の形態１から４に示した空気調和機において、熱交換器は円管プレートフィンチューブタイプの例を示したが、楕円管プレートフィンチューブタイプや、扁平管プレートフィンチューブタイプ、また楕円管・扁平管コルゲートフィンチューブタイプを用いても良い。またこれら熱交換器の製造において、特に伝熱管やフィンを炉中ろう付けにより接合すれば、ろう付けが一回で完了するため、ろう付け不良による冷媒漏れの確率が減少し、燃焼性のあるＲ３２やＲ２９０冷媒を用いたときの安全性をより確保することが出来る。また伝熱管とフィンの間の接触熱抵抗が激減し、熱交換器性能を高めることができる、加えて伝熱管とフィンを、銅、もしくはアルミニウムなど同一の材料とすれば、解体時のリサイクル性に優れた熱交換器を提供することができる。
【０１０１】
また本実施例１から４では冷媒としてＲ４１０ＡやＲ３２を用いる例を示したが、従来冷媒Ｒ２２と比較してＲ４１０ＡやＲ３２は動作圧力が高くなる（図３に示す点Ｄ、Ｅの高さ）ため、第２流量制御弁１０での流動抵抗を従来冷媒Ｒ２２より大きくし、第２流量制御弁１０での減圧量を従来冷媒Ｒ２２より大きくする必要がある。このため、例えば図１８に示す従来の第２流量制御弁１０では、主弁座３３と主弁体３４の隙間のオリィフィスをさらに小さくして流動抵抗を大きくする必要があり、Ｒ４１０Ａを用いた場合従来冷媒Ｒ２２より必然的に気液二相流が通過する際に非常に大きな冷媒流動音が発生してしまう。従って、本実施例に示した多孔質透過材を用いた第２流量制御弁１０をＲ４１０Ａ冷媒空気調和機に適用することにより、冷媒流動音を大幅に低減する効果をより一層発揮することができる。
【０１０２】
なお、以上実施形態１から４に述べた空気調和機においては、冷凍機油としては、ＨＣＦＣやＨＦＣ、ＨＣ冷媒や自然冷媒などの上述した冷媒に対して非相溶性または難溶性の冷凍機油、もしくは相溶性の冷凍機油であっても、アルキルベンゼン系、鉱油系、エステル油系、エーテル油系、フッ素油系など、どんな冷凍機油についても、その効果を達成することができる。
【０１０３】
なお、以上実施形態１から４に述べた空気調和機においては、室外ユニット１７と室内ユニット１８が１台ずつである空気調和機の例を示したが、室外ユニット１７が１台で室内ユニット１８が複数台である空気調和機においても、その効果は達成される。
【０１０４】
なお、上記実施の形態１から４に示した空気調和機において、圧縮機はどんな形式のもの、例えば、レシプロ圧縮機（単気筒、複数気筒）、ロータリー圧縮機（単気筒、複数気筒）、スクロール圧縮機、リニア圧縮機など、を用いても良い。また前記圧縮機シェル内に圧縮部を回転数させる電気モータを内蔵するとき、そのシェル内の圧力構造は、高圧でも低圧でも良い。高圧シェル方式では圧縮シリンダーを出た冷媒がモーターを冷却して加熱され圧縮機から吐出されるので、吐出温度は高くなる。一方低圧シェル方式ではシェル内に流入した冷媒はモーターを冷却して加熱されてから圧縮シリンダーに吸入されるので、吸入温度は高くなる。しかし圧縮シリンダーから流出する冷媒は直接圧縮機外へ吐出されるので、吐出温度は低くなる。使用する冷媒に応じて、吐出温度を高くするか低くするか、特にＲ３２冷媒はＲ４１０Ａ冷媒より吐出温度が高くなり、Ｒ２９０冷媒はＲ４１０Ａ冷媒より吐出温度が低くなるので、その冷媒の特性を考慮して高圧か低圧かを選択すればよい。また一般に低圧シェルより高圧シェルの方が圧縮機内冷凍機油への冷媒とけ込み量が多い。従って冷媒充填量を削減したいときには低圧シェル方式を選択した方が良いが、冷媒が溶けにくい冷凍機油を使用すれば高圧シェルでも冷媒量を削減することができる。
【０１０５】
本発明の実施形態１から４に示した空気調和機において、特に冷媒としては可燃性であるＲ２９０またはＲ３２などを用いたときの、第１流量制御弁２４、または第２流量制御弁１０、または第３流量制御弁８１、またはその全ての流量制御弁に全閉機能を備えた場合の効果について説明する。この時、冷媒漏れを検知する手段を併せ持つことにより、空調機運転中や停止中に冷媒漏れを検知した場合にはこれら流量制御弁を全閉することにより冷媒回路内に冷媒を封止し、室内への冷媒漏れを防止することができ、可燃性冷媒を用いた空気調和機での安全性を確保することができる。
【０１０６】
本発明は圧縮機、室内熱交換器、第１流量制御弁、室外熱交換器、四方弁を備えるとともに、室内熱交換器を分割しその間に第２流量制御弁を設けるとともに、第１流量制御弁と室内熱交換器の間に気液分離容器を有し、気液分離容器からのガスバイパス回路が圧縮機吸入に接続されていて、このガスバイパス回路上に第３流量制御弁を備えるとともに、四方弁を冷房回路に切り換え、冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、四方弁、圧縮機吸入へと流れ、第３流量制御弁は全閉とし、第１流量制御弁は全開として、第２流量制御弁にて流量制御を行う運転モードを有し、かつ四方弁を暖房回路に切り換え、冷媒が圧縮機吐出、四方弁、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、気液分離容器、第３流量制御弁、圧縮機吸入へと流れ、第３流量制御弁は全開とし、第２流量制御弁にて流量制御を行う運転モードを有するので、外気温条件によらず再熱除湿運転を行うことが出来、年間を通じて快適な室内環境を得ることが出来る。また第１流量制御弁もしくは第２流量制御弁もしくは第３流量制御弁の流動抵抗体として、冷媒流れ方向に連通する多孔質透過材を用いたので、流量制御弁を通過する冷媒流動音を大幅に低減することができ、さらに、流量制御弁の回りに遮音材や制振材を周囲に巻きつけるなどの対策も不要でコスト低減となり、さらにこれら他材質が不要となるため、空気調和機のリサイクル性も向上する。
【０１０７】
さらに第２流量制御弁の冷媒流れ上流側を再熱器、冷媒流れ下流側を蒸発器として動作させる再熱除湿運転モードの再熱器の冷媒流れ上流側に、熱的に遮断された補助熱交換器を備えたので、再熱熱交換器容量が拡大して再熱熱交換量が増加し、室温低下を防ぎながら再熱除湿する能力制御範囲を大きくすることが可能となる。また、室内ユニット内の空隙スペースを有効に活用することができ、室内ユニットのコンパクト化も可能となる。また通常暖房運転時の室内熱交換器能力を向上させることができる。また、補助熱交換器を再熱器の空気流れ風上側に設置したので、温度が低い空気と対向して冷媒が流れ、熱交換性能をより向上させることができる。また、補助熱交換器の通風抵抗を他の熱交換器より小さくしたので、通風側の圧力損失の増大を抑えながら熱交換性能を向上させることができる。
【０１０８】
また第２流量制御弁の冷媒流れ上流側を再熱器、冷媒流れ下流側を蒸発器として動作させる再熱除湿運転モードにて、室内での潜熱および顕熱の所要空調負荷を入力する装置と、室内での現在の潜熱および顕熱空調負荷を検知する手段を備えるとともに、室内熱交換器への送風量を調整する手段、室外熱交換器への送風量を調整する手段、圧縮機回転数を調整する手段、第１流量制御弁の開度を調整する手段を備え、第２流量制御弁の開度を調整する手段を備え、現在の室内での潜熱および顕熱の空調負荷の検知情報ならびに室内熱交換器送風量、室外熱交換器送風量、圧縮機回転数、第１流量制御弁開度、第２流量制御弁開度の現在値を基に、所要空調負荷に応じた室内熱交換器への送風量、室外熱交換器への送風量、圧縮機回転数、第１流量制御弁開度、第２流量制御弁開度の変化量を演算装置にて算出する手段を備え、この演算結果を基に、それぞれ個別またはいくつかを組み合わせて調整することにより、室内での潜熱および顕熱熱交換量を制御するので、室内での潜熱および顕熱負荷に応じて、潜熱および顕熱熱交換量を制御することができる。また、請求項３に係る発明によれば、第１流量制御弁と気液分離容器まわりの冷媒回路に、逆止弁を４つ接続し、冷房回路、暖房回路とも、第１流量制御弁にて減圧された冷媒を気液分離容器にて気液分離する冷媒流れとなるので、冷房、暖房時も高効率な運転を実現することが出来る。
【０１０９】
【発明の効果】
本発明にかかわる空気調和機は、圧縮機、室内熱交換器、第１流量制御弁、室外熱交換器、四方弁を有し冷媒を循環させる冷媒回路を備えた空気調和機において、前記室内熱交換器を分割しその間に設けられた第２流量制御弁と、前記第１流量制御弁と前記室内熱交換器又は前記室外熱交換器との間に設けられた気液分離容器と、前記気液分離容器から圧縮機吸入に接続されたバイパス回路上に第３流量制御弁を有するガスバイパス回路と、を備え、前記四方弁を暖房回路として前記冷媒が圧縮機吐出、四方弁、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、気液分離容器、第３流量制御弁、圧縮機吸入へと流れ、前記第３流量制御弁は全開とし、前記第１流量制御弁を全閉として、前記第２流量制御弁にて流量制御を行う暖房回路での再熱除湿運転モードを有するので、効率よく、簡単に除湿運転を実現することが出来る。
【０１１２】
本発明にかかわる空気調和機は、前記四方弁を冷房回路として、前記冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、四方弁、圧縮機吸入へと流れるとともに、前記気液分離容器にて分離されたガス冷媒が前記第３流量制御弁を通って前記圧縮機吸入へと流れ、前記第２流量制御弁は全開とし、前記第１流量制御弁にて主たる冷媒回路の流量制御を、前記第３流量制御弁にて前記ガスバイパス回路の流量制御を行う冷房運転モードを有するので、冷房能力の増加やこう高率な冷房運転を行える。
【０１１３】
本発明にかかわる空気調和機は、四方弁を暖房回路として、冷媒が圧縮機吐出、四方弁、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、気液分離容器、第１流量制御弁、室外熱交換器、四方弁、圧縮機吸入へと流れ、前記第３流量制御弁は全閉とし、前記第２流量制御弁を全開として、第１流量制御弁にて流量制御を行う暖房運転モードを有するので、暖房能力の増加や高効率な暖房運転を実現することが出来る。
【０１１４】
本発明にかかわる空気調和機は、暖房除霜運転の際、前記四方弁を冷房回路に切り換え、前記冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、第３流量制御弁、圧縮機吸入へと流れ、前記第１流量制御弁、前記第３流量制御弁を全開とした運転モードを有するので、短時間な除霜運転により、快適な室内環境を得ることが出来、且つ、省エネルギー運転を実現することが出来る。
【０１１５】
本発明にかかわる空気調和機は、圧縮機、室内熱交換器、第１流量制御弁、室外熱交換器、四方弁を有し冷媒を循環させる冷媒回路を備えた空気調和機において、前記室内熱交換器を分割しその間に設けられた第２流量制御弁と、前記第１流量制御弁と前記室内熱交換器又は前記室外熱交換器との間に設けられた気液分離容器と、前記気液分離容器から圧縮機吸入に接続されたバイパス回路上に第３流量制御弁を有するガスバイパス回路と、前記室内熱交換器を設けた室内ユニットの室内空気を吸い込む吸い込み口に設けられた温湿度検知手段にて検知した吸込み空気の温湿度とあらかじめ設定された温湿度との偏差により室内の空調付加を求める潜熱顕熱負荷検知装置と、を備え、少なくとも冷房回路での再熱除湿運転及び暖房回路での再熱除湿運転の運転モードを有し、前記潜熱顕熱負荷検知装置にて検知した負荷が、あらかじめ各運転モードにて設定した潜熱顕熱能力制御範囲内か否かにより、運転モードを切り換えて動作するので、室内負荷の能力変化に応じてフレキシブルで高効率な運転を実現することが出来る。
【０１１６】
また、請求項８に係る発明によれば、圧縮機、室内熱交換器、第１流量制御弁、室外熱交換器、四方弁を備えた空気調和機において、室内熱交換器を分割しその間に第２流量制御弁を設けるとともに、第１流量制御弁と室内熱交換器の間に気液分離容器を有し、気液分離容器からのガスバイパス回路が圧縮機吸入に接続されていて、このガスバイパス回路上に第３流量制御弁を備えるとともに、四方弁を冷房回路として、冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、四方弁、圧縮機吸入へと流れ、第３流量制御弁は全閉とし、第１流量制御弁又は第２流量制御弁にて流量制御を行う第１の運転モードと、四方弁を暖房回路として、冷媒が圧縮機吐出、四方弁、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、気液分離容器、第３流量制御弁、圧縮機吸入へと流れ、第３流量制御弁は全開とし、第２流量制御弁にて流量制御を行う第２の運転モードとを有し、第１の運転モードと第２の運転モードは交互に切り替え可能なので、室内負荷の能力変化に応じて高効率な運転を実現することが出来る。
【０１１７】
また、請求項９に係る発明によれば、、四方弁を冷房回路に切り換え、冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、上流側室内熱交換器、第２流量制御弁、下流側室内熱交換器、四方弁、圧縮機吸入へと流れるとともに、気液分離容器にて分離されたガス冷媒が第３流量制御弁を通って圧縮機吸入へと流れ、第２流量制御弁は全開とし、第１流量制御弁にて主たる冷媒回路の流量制御を、第３流量制御弁にてガスバイパス回路の流量制御を行う第３の運転モードを有し，第１運転モードと交互に切替可能なので、運転モードの変化や室内負荷の能力変化にスムースに対応できる高効率な運転を実現することが出来る。
【０１１８】
また、請求項１０に係る発明によれば、第１流量制御弁の弁開度制御は室内熱交換器出口冷媒過熱度に相当する値を、第３流量制御弁の弁開度制御は、圧縮機吸入冷媒過熱度、圧縮機吐出冷媒過熱度、圧縮機吐出冷媒温度に相当する値を目標として流量制御を行う運転モードを有するので、高効率かつ信頼性の高い運転を実現することが出来る。
【０１１９】
また、請求項１１に係る発明によれば、第３流量制御弁の弁開度制御は、圧縮機回転数に応じて流量制御を行う運転モードを有するので、能力変化に応じて高効率な運転を実現することが出来る。
【０１２０】
また、請求項１２に係る発明によれば、暖房除霜運転の際、四方弁を冷房回路に切り換え、冷媒が圧縮機吐出、四方弁、室外熱交換器、第１流量制御弁、気液分離容器、第３流量制御弁、圧縮機吸入へと流れ、第１流量制御弁、第３流量制御弁を全開とした運転モードを有するので、除霜時間を短縮することが出来、快適な室内環境を速く得ることが出来る。
【０１２１】
また、請求項１３に係る発明によれば、第２流量制御弁の冷媒流れ上流側を再熱器、冷媒流れ下流側を蒸発器として動作させる再熱除湿運転モードの再熱器の冷媒流れ上流側に、前記再熱器と熱的に遮断された補助熱交換器を備えたので、再熱除湿運転時の再熱熱交換量を増加させることができ，広範囲な潜熱顕熱能力制御運転を実現することができる。
【０１２２】
また、請求項１４に係る発明によれば、補助熱交換器の冷媒流路を一系統としたので、気液分離機使用時の運転の管内冷媒熱伝達性能を向上させることができ，室内熱交換器の暖房能力がより向上し高効率な運転ができる。
【０１２３】
また、請求項１５に係る発明によれば、第１流量制御弁もしくは第２流量制御弁もしくは第３流量制御弁の流動抵抗体として、冷媒流れ方向に連通する多孔質透過材を用いたので、流量制御弁を通過する冷媒流動音を大幅に低減することができて、さらに騒音防止対策用の特殊材質が不要となるため、空気調和機のリサイクル性も向上する。
【０１２４】
また、請求項１６に係る発明によれば、第２流量制御弁の代わりに絞り装置として、オリフィスとこの冷媒流れ上流方向、もしくは下流方向、もしくは上下流方向に、オリフィスを挟み込む構造で冷媒流れ方向に連通する多孔質透過材を配置、または多孔質透過材を単独に配置して、流動抵抗体として作用させるとともに、この絞り装置をバイパスする冷媒流路と、このバイパス流路を開閉する手段とを備えたので、第２流量制御弁を通過する冷媒流動音が大幅に低減されるとともに、第２流量制御弁の構造が簡略化され、コスト低減を図ることができる。
【０１２５】
また、請求項１７に係る発明によれば、バイパス流路を開閉する手段として、双方向流れに対して封止可能な開閉弁を用いたので、冷房回路、暖房回路でも再熱除湿運転を実現することが出来、外気温条件に寄らず、快適な室内環境を得ることが出来る。
【０１２６】
また請求項１８に係る発明によれば、第１流量制御弁と気液分離容器を接続した回路に、冷房方向、暖房方向とも、第１流量制御弁にて減圧された冷媒を気液分離容器にて気液分離する冷媒流れとなる様に第１流量制御弁から前記気液分離容器への流れが常に一定なる切替回路を接続した冷房，暖房時とも高い効率の運転を実現できる。
【０１２７】
また、請求項１９に係る発明によれば、圧縮機吸入側に液だめ容器を設けたので、冷媒回路内の余剰冷媒を吸収し、高効率かつ信頼性の高い運転を実現することが出来る。
【０１２８】
また、請求項２０に係る発明によれば、第３流量制御弁として、毛細管と電磁開閉弁で構成したので、簡素な構成で低コスト化することが出来る。
【０１２９】
また、請求項２１に係る発明によれば、冷媒としてＲ４１０ＡまたはＲ３２またはＲ２９０を用いたので、オゾン層破壊防止や地球温暖化に役立つことができる。
【０１３０】
また、請求項２２に係る発明によれば、冷媒としてＲ２９０またはＲ３２を用い、第１流量制御弁または第２流量制御弁、またはその両方の流量制御弁に全閉機能を備えるとともに、冷媒漏れを検知する手段を備え、冷媒漏れを検知した場合にはこれら流量制御弁を全閉する手段を備えたので、可燃性冷媒に対する室内への冷媒漏洩を防止し、機器の安全性を確保することができる。
【０１３１】
また、請求項２３に係る発明によれば、室内空気状態の目標値を設定する空気状態設定手段と，室内の空気状態を検出する空気状態検出手段と、室内熱交換器への送風量を調整する室内送風量調整手段と，室外熱交換器への送風量を調整する室外送風量調整手段と、圧縮機の回転数を調整する圧縮機回転数調整手段と、第１流量制御弁の開度を調整する第１流量制御弁開度調整手段と、第２流量制御弁の開度を調整する第２流量制御弁開度調整手段と、を備えた空気調和機において、第２流量制御弁の冷媒流れ上流側の室内熱交換器を再熱器、冷媒流れ下流側の室内熱交換器を蒸発器として動作させる再熱除湿運転モードにて空気調和機を運転するステップと、運転中の前記空気調和機の室内空気状態の目標値と検出値から室内での潜熱および顕熱の空調負荷の目標値と検出値の差異を求めるステップと，室内の潜熱および顕熱の空気負荷の差異を少なくする方向に、室内熱交換器への送風量、室外熱交換器への送風量、圧縮機の回転数、第１流量制御弁の開度、及び第２流量制御弁の開度の少なくともいずれか１つを変化させるステップと，を備えたので，室内の空気負荷に応じた運転が可能になり，使い勝手が良くエネルギー使用量が少ない空気調和機の運転方法が得られる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態における冷媒回路図である。
【図２】本発明の第１の実施形態における室内ユニットの構成を表す図である。
【図３】本発明の第１の実施形態における冷房回路での再熱除湿運転時の動作状態を表す特性図である。
【図４】本発明の第１の実施形態における暖房回路での再熱除湿運転時の動作状態を表す特性図である。
【図５】本発明の第１の実施形態における気液分離回路での動作状態を表す特性図である。
【図６】本発明の第１の実施形態における冷媒回路図およびセンサ、アクチュエータの構成図である。
【図７】本発明の第１の実施形態において、能力制御範囲と運転切り換えの動作マップを表す図である。
【図８】本発明の第１の実施形態における室内ユニットの他の構成を表す図である。
【図９】本発明の第１の実施形態における室内ユニットのさらに他の構成を表す図である。
【図１０】本発明の第１の実施形態における第２流量制御弁の構成を表す図である。
【図１１】本発明の第２の実施形態における冷媒回路図である。
【図１２】本発明の第２の実施形態における第２流量制御弁の構成を表す図である。
【図１３】本発明の第３の実施形態における冷媒回路図である。
【図１４】本発明の第４の実施形態における冷媒回路図である。
【図１５】本発明の第１のから第４の実施形態における気液分離容器の構成を表す図である。
【図１６】本発明の第１のから第４の実施形態における気液分離容器の構成を表す図である。
【図１７】従来の発明における室内ユニットの構成を表す図である。
【図１８】従来の発明における冷媒回路図である。
【図１９】従来の発明における第２流量制御弁の構成を表す図である。
【符号の説明】
５：室内送風機、１０：第２流量制御弁、１４：補助熱交換器、１７：室外ユニット、１８：室内ユニット、２１：圧縮機、２３：室外熱交換器、２４：第１流量制御弁、２５：第１室内熱交換器、２７：第２室内熱交換器、３８：発泡金属、８０：ガスバイパス回路、８１：第３流量制御弁、８２：気液分離容器。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner that uses the heat of condensation of a refrigeration cycle as a heating source for indoor air, and enhances controllability of temperature and humidity during each operation of cooling, dehumidification, heating, etc. It is related with the air conditioner which improves the comfort with respect to indoor temperature, humidity, and noise by reducing.
[0002]
[Prior art]
In a conventional air conditioner, a variable speed compressor or the like is mainly used to cope with fluctuations in the air conditioning load. However, at the time of cooling low capacity operation, although the rotation speed of the compressor is lowered, there is a problem that the evaporating temperature rises to be higher than the dew point temperature of the indoor air and cannot be dehumidified.
[0003]
As a conventional technique for improving the dehumidifying capacity during cooling low capacity operation, there is an air conditioner shown in FIG. 17 of Japanese Patent Laid-Open No. 9-42706. According to this apparatus, the air conditioner is provided with a compressor, a four-way valve, an indoor heat exchanger, a first flow control valve, and an outdoor heat exchanger, and the indoor heat exchanger is disposed so as to surround the blower from the front to the back of the indoor unit. In this machine, the indoor heat exchanger is thermally divided and a second flow rate control valve 10 is provided between them, and the second flow rate control valve 10 has a refrigerant flow upstream side as a reheater and a refrigerant flow downstream side as an evaporator. The dehumidifying capacity is secured in the operation mode operated as At this time, the heat exchanger installed from the front upper stage to the back acts as a reheater.
[0004]
FIG. 18 shows a refrigerant circuit diagram in Japanese Patent Laid-Open No. 9-42706. A compressor, a four-way valve, an indoor heat exchanger, a first flow control valve, and an outdoor heat exchanger are provided, and the indoor heat exchanger is thermally divided and a second flow control valve 10 is provided therebetween. The flow direction of the refrigerant is the direction of the solid arrow in FIG. 18 with the four-way valve as the cooling direction during the reheat dehumidifying operation in the cooling circuit, and the second flow control valve 10 is used as the main flow control valve. Further, during the heating operation, the four-way valve is set as the heating direction and the arrow direction indicated by the dotted line in FIG. 18 is used, and the first flow control valve 24 is used as the main flow control valve.
[0005]
[Problems to be solved by the invention]
However, in Japanese Patent Laid-Open No. 9-42706, since the second flow rate control valve is installed in the indoor heat exchanger, the refrigerant pressure loss here is large, which causes a decrease in efficiency in normal cooling operation and heating operation. There is a problem.
[0006]
In addition, the second flow rate control valve shown in FIG. 18 used in Japanese Patent Application Laid-Open No. 9-42706 uses a normal orifice type expansion valve, so that there is a problem that the refrigerant flow noise is large. It is not sufficiently small as compared with the blowing sound, and measures such as attaching a soundproof and sound absorbing material are required.
[0007]
In the conventional air conditioner, R22 is used as a refrigerant, but replacement with R410A or the like is in progress to prevent destruction of the ozone layer. Since the operating pressure of R410A is higher than that of R22, the differential pressure at the second flow rate control valve is also increased, causing a problem that the refrigerant flow noise is increased.
[0008]
In addition, when the refrigerant flow in the refrigerant circuit in Japanese Patent Laid-Open No. 9-42706, FIG. 18 is switched to the heating direction in order to perform the reheat dehumidifying operation in the heating circuit, the indoor heat exchanger on the downstream side of the second flow control valve However, since the outdoor heat exchanger capacity is large, there is a problem that the evaporation temperature of the indoor heat exchanger does not drop below the dew point temperature of the indoor air and cannot be dehumidified.
[0009]
The present invention was made to solve the above-described problems, and in an air conditioner that uses the heat of condensation of a refrigeration cycle as a heating source for indoor air, each of cooling, dehumidification, heating, Increases controllability of temperature and humidity during operation, realizes reheat dehumidification operation regardless of the cooling season and heating season, and improves the efficiency during normal cooling and heating operation. An object of the present invention is to reduce the refrigerant flow noise by utilizing the characteristics of the refrigerant.
[0010]
[Means for Solving the Problems]
An air conditioner according to the present invention includes a compressor, an indoor heat exchanger, a first flow control valve, an outdoor heat exchanger, a four-way valve, and an air conditioner provided with a refrigerant circuit that circulates the refrigerant. A second flow rate control valve provided between the divided exchangers, a gas-liquid separation container provided between the first flow rate control valve and the indoor heat exchanger or the outdoor heat exchanger, A gas bypass circuit having a third flow rate control valve on a bypass circuit connected to the compressor suction from the liquid separation container, wherein the refrigerant is discharged from the compressor, the four-way valve, and the upstream chamber using the four-way valve as a heating circuit Heat exchanger, second flow rate control valve, downstream indoor heat exchanger, gas-liquid separation container, third flow rate control valve, flow into compressor suction, the third flow rate control valve is fully open, and the first flow rate control The valve is fully closed and the second flow control valve is used to control the flow rate. Those having a reheat dehumidification operation mode in the circuit.
[0013]
An air conditioner according to the present invention uses the four-way valve as a cooling circuit, and the refrigerant is discharged from a compressor, a four-way valve, an outdoor heat exchanger, a first flow control valve, a gas-liquid separation container, an upstream indoor heat exchanger, The second flow control valve, the downstream indoor heat exchanger, the four-way valve, and the compressor suction flow, and the gas refrigerant separated in the gas-liquid separation container passes through the third flow control valve and sucks the compressor. A cooling operation mode in which the second flow rate control valve is fully open, the flow rate control of the main refrigerant circuit is controlled by the first flow rate control valve, and the flow rate control of the gas bypass circuit is controlled by the third flow rate control valve. It is what has.
[0014]
An air conditioner according to the present invention uses a four-way valve as a heating circuit, refrigerant is discharged from a compressor, a four-way valve, an upstream indoor heat exchanger, a second flow control valve, a downstream indoor heat exchanger, a gas-liquid separation container, The first flow control valve, the outdoor heat exchanger, the four-way valve, and the compressor flow, the third flow control valve is fully closed, the second flow control valve is fully opened, and the first flow control valve is used for flow. It has a heating operation mode for performing control.
[0015]
The air conditioner according to the present invention switches the four-way valve to a cooling circuit during the heating and defrosting operation, and the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow control valve, and the gas-liquid separation container. The third flow control valve flows into the compressor suction, and has an operation mode in which the first flow control valve and the third flow control valve are fully opened.
[0016]
An air conditioner according to the present invention includes a compressor, an indoor heat exchanger, a first flow control valve, an outdoor heat exchanger, a four-way valve, and an air conditioner provided with a refrigerant circuit that circulates the refrigerant. A second flow rate control valve provided between the divided exchangers, a gas-liquid separation container provided between the first flow rate control valve and the indoor heat exchanger or the outdoor heat exchanger, Gas bypass circuit having a third flow rate control valve on the bypass circuit connected to the compressor suction from the liquid separation container, and temperature and humidity provided at the suction port for sucking indoor air of the indoor unit provided with the indoor heat exchanger A latent heat sensible heat load detection device that requires addition of air conditioning in the room by a deviation between the temperature and humidity of the intake air detected by the detection means and a preset temperature and humidity, and at least reheat dehumidification operation and heating in the cooling circuit Re-in circuit It has an operation mode of dehumidification operation, and operates by switching the operation mode depending on whether the load detected by the latent heat sensible heat load detection device is within the latent heat sensible heat capacity control range set in advance in each operation mode. Is.
[0017]
An air conditioner according to an eighth aspect of the present invention is an air conditioner including a compressor, an indoor heat exchanger, a first flow control valve, an outdoor heat exchanger, and a four-way valve. Provided with a second flow rate control valve, a gas-liquid separation container between the first flow control valve and the indoor heat exchanger, a gas bypass circuit from the gas-liquid separation container is connected to the compressor suction, A third flow rate control valve is provided on the gas bypass circuit, the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow rate control valve, the gas-liquid separation container, the upstream chamber, and the four-way valve as a cooling circuit. Heat exchanger, second flow control valve, downstream indoor heat exchanger, four-way valve, flow into compressor intake, third flow control valve fully closed, with first flow control valve or second flow control valve The first operation mode for controlling the flow rate and the four-way valve as a heating circuit, the refrigerant is a compressor Outlet, four-way valve, upstream indoor heat exchanger, second flow control valve, downstream indoor heat exchanger, gas-liquid separation container, third flow control valve, flow into compressor intake, third flow control valve fully open And a second operation mode in which the flow rate is controlled by the second flow rate control valve, and the first operation mode and the second operation mode can be switched alternately.
[0018]
In the air conditioner according to claim 9 of the present invention, the four-way valve is switched to the cooling circuit, and the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow control valve, the gas-liquid separation container, the upstream side indoor heat. The refrigerant flows into the exchanger, the second flow control valve, the downstream indoor heat exchanger, the four-way valve, and the compressor suction, and the gas refrigerant separated in the gas-liquid separation container passes through the third flow control valve and sucks the compressor. The third flow rate control valve is fully open, the first flow rate control valve controls the flow rate of the main refrigerant circuit, and the third flow rate control valve controls the flow rate of the gas bypass circuit. However, it can be switched alternately with the first operation mode.
[0019]
In the air conditioner according to claim 10 of the present invention, the valve opening control of the first flow control valve is a value corresponding to the degree of refrigerant heat at the outlet of the indoor heat exchanger, and the valve opening control of the third flow control valve is There is an operation mode in which the flow rate control is performed with the target values corresponding to the compressor suction refrigerant superheat degree, the compressor discharge refrigerant superheat degree, and the compressor discharge refrigerant temperature.
[0020]
The valve opening degree control of the third flow rate control valve of the air conditioner according to claim 11 of the present invention has an operation mode in which the flow rate control is performed according to the compressor rotational speed.
[0021]
In the air conditioner according to claim 12 of the present invention, the four-way valve is switched to the cooling circuit, and the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow control valve, the gas-liquid separation container, and the third flow control. The valve has a fourth operation mode in which the first flow control valve and the third flow control valve are fully opened.
[0022]
In the air conditioner according to claim 13 of the present invention, the refrigerant flow of the reheater in the reheat dehumidification operation mode in which the second flow rate control valve is operated with the refrigerant flow upstream side as the reheater and the refrigerant flow downstream side as the evaporator. An auxiliary heat exchanger that is thermally shut off from the reheater is provided on the upstream side.
[0023]
In an air conditioner according to a fourteenth aspect of the present invention, the refrigerant flow path of the auxiliary heat exchanger is a single system.
[0024]
An air conditioner according to a fifteenth aspect of the present invention uses a porous permeable material communicating in the refrigerant flow direction as a flow resistor of the first flow control valve, the second flow control valve, or the third flow control valve. It is.
[0025]
According to a sixteenth aspect of the present invention, an air conditioner according to a sixteenth aspect of the present invention has a structure in which an orifice is sandwiched between an orifice and the refrigerant flow upstream, downstream, or upstream / downstream as a throttle device instead of the second flow control valve. A porous permeation material communicating in the direction is arranged, or a porous permeation material is arranged alone to act as a flow resistor, and a refrigerant flow path that bypasses the throttling device and means for opening and closing the bypass flow path It is equipped with.
[0026]
The air conditioner according to claim 17 of the present invention uses an on-off valve capable of sealing against bidirectional flow as means for opening and closing the bypass flow path.
[0027]
In an air conditioner according to claim 18 of the present invention, the refrigerant decompressed by the first flow control valve in the cooling direction and the heating direction is supplied to the circuit in which the first flow control valve and the gas-liquid separation container are connected. A switching circuit in which the flow from the first flow rate control valve to the gas-liquid separation container is always constant is connected so that the refrigerant flow is gas-liquid separated in the separation container.
[0028]
According to a nineteenth aspect of the present invention, there is provided a liquid reservoir on the compressor suction side.
[0029]
In an air conditioner pertaining to a twentieth aspect of the present invention, the third flow control valve comprises a capillary tube and an electromagnetic on-off valve.
[0030]
The air conditioner according to claim 21 of the present invention uses R410A, R32, or R290 as the refrigerant.
[0031]
The air conditioner according to claim 22 of the present invention uses R290 or R32 as the refrigerant, and is fully closed to at least one of the first flow control valve, the second flow control valve, and the third flow control valve. In addition to having a function, a means for detecting a refrigerant leak is provided, and a means for fully closing the flow rate control valve when a refrigerant leak is detected.
[0032]
According to a twenty-third aspect of the present invention, there is provided an air conditioner operating method comprising: an air condition setting means for setting a target value of an indoor air condition; an air condition detection means for detecting the indoor air condition; and an indoor heat exchanger. The indoor air flow rate adjusting means for adjusting the air flow rate of the air, the outdoor air flow rate adjusting means for adjusting the air flow rate to the outdoor heat exchanger, the compressor rotational speed adjusting means for adjusting the rotational speed of the compressor, and the first flow rate An air conditioner comprising: a first flow control valve opening adjustment unit that adjusts an opening of a control valve; and a second flow control valve opening adjustment unit that adjusts an opening of a second flow control valve. Operating the air conditioner in a reheat dehumidifying operation mode in which the indoor heat exchanger on the upstream side of the refrigerant flow of the second flow rate control valve is operated as a reheater, and the indoor heat exchanger on the downstream side of the refrigerant flow is operated as an evaporator; Target value and detected value of indoor air condition of the air conditioner during operation Determining the difference between the target value and the detected value of the indoor latent heat and sensible heat air conditioning load, and sending the difference to the indoor latent heat and sensible heat air load in the direction of reducing the difference between the indoor latent heat and sensible heat air load. A step of changing at least one of an air volume, an air flow rate to the outdoor heat exchanger, a rotation speed of the compressor, an opening degree of the first flow rate control valve, and an opening degree of the second flow rate control valve. Is.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
An air conditioner according to a first embodiment of the present invention is shown in FIGS. FIG. 1A is a refrigerant circuit diagram, and FIG. 2 is a cross-sectional view of an indoor unit. In the refrigerant circuit diagram shown in FIG. 1A, the outdoor unit 17 includes a variable speed compressor 21, a four-way valve 22, an outdoor heat exchanger 23, a first flow control valve 24, a gas-liquid separation container 82, and a gas-liquid. A gas bypass circuit 80 that separates the gas refrigerant from the separation container 82 and is connected to the compressor suction, and a third flow rate control valve 81 on the gas bypass circuit 80, the indoor heat exchanger of the indoor unit 18 is a thermal Are divided into a first indoor heat exchanger 25 and a second indoor heat exchanger 27, and a second flow rate control valve 10 is provided therebetween. R410A or R32 or R290 is used as the refrigerant. In FIG. 2, the indoor heat exchanger incorporated in the indoor unit is, for example, a plate fin tube type heat exchanger and has a multistage bending structure, and surrounds the blower 5 (an example of a cross-flow blower) from the front to the back. The second flow control valve 10 is provided. 11 is a heat transfer tube, 12 is a heat transfer tube connection pipe on the front side, 13 is a heat transfer tube connection pipe on the back side, and 28 is a heat transfer fin. This indoor heat exchanger has a four-stage bending structure of a front lower part 4, a front front part 2, a front upper oblique part 1, and a rear part 3, and each part is thermally blocked. 6 is a drain pan for the front lower stage heat exchanger, 7 is a drain pan for the back heat exchanger, 8 is an air suction grille, 9 is a suction air flow direction, 29 is an air outlet, and 19 is a blow air flow direction. The air sucked from the air suction grille 8 from the direction 9 is sucked by the blower 5, and from the suction air flow direction 9d to the front lower part 4, 9b to the front front part 2, 9a to the front upper oblique part 1, 9c to the rear Heat is exchanged through each of the four portions of the portion 3 and blown out in the direction 19 from the air blowout port 29.
[0034]
Each of the first flow control valve 24, the second flow control valve 10, the third flow control valve 81, and the four-way valve 22 provided in the refrigerant circuit of FIG. 1 (a) is cooling, heating, cooling reheat dehumidification, heating. The operation shown in various operation modes such as reheat dehumidification and heating defrosting is shown in FIG. In the figure, fully open indicates a fully open state without adjusting the opening, and simply opening indicates that the opening of the flow control valve is adjusted. The cooling direction and heating direction of the four-way valve indicate that the refrigerant flow direction is the flow during cooling and the flow during heating. In the path pattern of the indoor heat exchanger shown in FIG. 2, when the four-way valve 22 shown in FIG. 1 (a) is in the reheat dehumidifying operation direction in the cooling circuit, that is, when the refrigerant flow direction is the direction of the solid arrow. In this example, the refrigerant inlet pipe is 15 and the refrigerant outlet pipe is 16 and connected from the first flow rate control valve 24 to the pipe 15 and from the pipe 16 to the four-way valve 22 in FIG. The 1st indoor heat exchanger 25 of the indoor heat exchanger used as a reheater is arrange | positioned at the front upper stage diagonal part 1 and the front front part 2 which become the refrigerant | coolant flow upstream of the 2nd flow control valve 10, and becomes an evaporator. The second indoor heat exchanger 27 of the indoor heat exchanger is disposed in the back surface portion 3 and the front lower portion 4 on the downstream side of the refrigerant flow of the second flow control valve 10, and a reheater is also provided below the evaporator. It has an arranged structure. The operation during operation in the refrigerant circuit of FIG. 1 will be described below.
[0035]
In FIG. 1 (a), during the reheat dehumidifying operation in the cooling circuit, the opening of the first flow control valve 24 is opened, the third flow control valve 81 is closed, and the second flow control valve 10 is mainly decompressed. The refrigeration cycle is used as a device. FIG. 3 shows a pressure-enthalpy diagram in the refrigeration cycle during the reheat dehumidification operation in this cooling circuit. A to G in FIG. 3 respectively correspond to A to G in the refrigerant circuit in FIG. 1A, and the refrigerant flow direction during the reheat dehumidifying operation in the cooling circuit is indicated by a solid line in FIG. Shown with an arrow. The refrigerant discharged from the compressor 21 and passing through the four-way valve 22 is condensed from the point A by the outdoor heat exchanger 23 to become the point B, and is slightly depressurized by the first flow control valve 24 to become the point C. It flows into the exchanger 25. At this time, the first indoor heat exchanger 25 acts as a reheater and recondenses to the point D. Thereafter, the pressure is reduced to the point E through the second flow rate control valve 10 and flows into the second indoor heat exchanger 27. At this time, the second indoor heat exchanger 27 acts as an evaporator, evaporates to the point F, and becomes a refrigeration cycle returning to the suction G of the compressor 21. At this time, in the indoor unit 18, the air cooled and dehumidified by the second indoor heat exchanger 27 and the air heated by the first indoor heat exchanger 25 are mixed and blown out. Therefore, at the time of reheat dehumidification operation in this cooling circuit, dehumidification can be performed while preventing a decrease in room temperature.
[0036]
In the reheat dehumidifying operation described above, as shown in FIG. 2, the first indoor heat exchanger 25 serving as a reheater includes an upper front oblique portion 1 and a front front portion on the refrigerant flow upstream side of the second flow control valve. 2 is arranged so as to surround the blower 5, and the second indoor heat exchanger 27 of the indoor heat exchanger serving as an evaporator is disposed on the back surface portion 3 and the front lower portion 4 on the downstream side of the refrigerant flow of the second flow control valve. Since it is arranged so as to surround the blower 5, the air sucked and heated from the oblique upper surface 9 a and the front surface 9 b of the indoor unit 18 and the air cooled and dehumidified from the back surface 9 c and the lower front surface 9 d are efficiently mixed by the blower 5. Is done. In particular, compared with the conventional example, by making the back surface portion 3 act as an evaporator, the air 9c that has passed through the back surface portion 3 and has been dehumidified and cooled, and the air 9a that has been heated through the front top oblique portion 1 are particularly Well mixed. Therefore, the air 19 blown out from the air outlet 29 becomes dehumidified air with no temperature drop compared to the intake air, and the air is blown out without temperature unevenness, so that a very comfortable indoor environment can be created. it can.
[0037]
In addition, since the heated air 9a and 9b and the cooled and dehumidified air 9c and 9d are sucked into the blower 5 in a distributed state and are mixed efficiently, there is no temperature unevenness on the blower 5 or the wall surface of the blowout port 29. The problem of reliability that dew adheres to the locally cooled portion and dew is blown out from the outlet 29 together with the blown air can be solved. Further, since the air 9c and 9d cooled and dehumidified from both sides of the heated air 9a and 9b are mixed, the air can be mixed in two places. Therefore, the large amount of the cooled and dehumidified air and the heated air is large. It is possible to solve the problem of reliability that dew is generated at the interface due to contact between the lumps and dew is blown out from the outlet 29 together with the blown air.
[0038]
Moreover, the 2nd indoor heat exchanger 27 used as an evaporator is arrange | positioned so that the air blower 5 may be enclosed in the back surface part 3 and the front lower stage part 4, and the drain pans 6 and 7 are installed in each heat exchanger lower part. Therefore, dew does not blow out from the air outlet 29 together with the blown air, and the heat exchanger 3 without the first indoor heat exchanger 25 receiving dripping of dew generated from the second indoor heat exchanger 27, Since the dew that has been dehumidified through 4 can be directly collected by the drain pans 6 and 7, reliability can be ensured.
[0039]
Subsequently, in FIG. 1A, the refrigerant flow direction during the reheat dehumidifying operation in the heating circuit is indicated by a dotted arrow. FIG. 4 shows a pressure-enthalpy diagram in the refrigeration cycle in the reheat dehumidification operation in the heating circuit. A to G in FIG. 4 correspond to A to G in the refrigerant circuit in FIG. 1, respectively. The refrigerant discharged from the compressor 21 and passing through the four-way valve 22 is condensed from the point F by the second indoor heat exchanger 27 to the point E, depressurized by the second flow control valve 10 and becomes the point D, and the first room It flows into the heat exchanger 25. At this time, the second indoor heat exchanger 27 acts as a reheater, and the first indoor heat exchanger 25 acts as an evaporator. Thereafter, the refrigerant enters the gas-liquid separation container 82 through the point C, and returns to the suction G of the compressor 21 through the gas bypass circuit 80 and the third flow rate control valve 81. The operation in the case where supercooling cannot be achieved at point E is the operation of dotted lines E ′ and D ′ in FIG. At this time, the first flow rate control valve 24 is fully closed to prevent refrigerant from flowing into the outdoor heat exchanger 23, and the third flow rate control valve 81 is fully open to prevent flow resistance. For this reason, since the refrigerant must evaporate in the first indoor heat exchanger 25, the evaporating temperature is necessarily lower than the indoor air temperature. However, although the evaporation temperature is lower than the room air temperature, it cannot be dehumidified unless it is equal to or lower than the dew point temperature of the room air. In this case, the temperature of the refrigerant flowing in the heat exchanger is connected to the first indoor heat exchanger 25 acting as an evaporator. Each unit is equipped with an indoor temperature and humidity measuring device, which is a device for detecting the dew point temperature of indoor air, and a measuring device for the indoor temperature and humidity, etc. When the dew point temperature is higher than the indoor dew point, the dew point of the room air can be reduced by decreasing the air volume of the indoor fan 5 to lower the evaporation temperature, or increasing the compressor rotation speed to increase the refrigerant flow rate and lowering the evaporation temperature. What is necessary is just to do below temperature. Thereby, in the indoor unit 18, the air cooled and dehumidified by the first indoor heat exchanger 25 and the air heated by the second indoor heat exchanger 27 are mixed and blown out regardless of the outside air temperature condition.
[0040]
The characteristics of the reheat dehumidification operation in the heating circuit and the reheat dehumidification operation in the cooling circuit will be compared based on FIGS. The enthalpy difference, which is the difference in the latent heat energy of the refrigerant in the reheater in FIG. 3, is CD, but the enthalpy difference in the reheater in FIG. In the case where there is no point (in FIG. 4, the adiabatic pressure reduction is indicated by the dotted line E′-D ′), the point E ′ is larger than FIG. Therefore, since the enthalpy difference representing the energy difference at different state points of the refrigerant is larger, the heating circuit can take a larger amount of heat exchange in the reheater. Therefore, by performing the reheat dehumidification operation in the heating circuit, it is possible to perform dehumidification without lowering the room temperature or dehumidifying while raising the room temperature. In other words, regardless of the outside air temperature condition, the cooling season, and the heating season, the reheat dehumidification operation in the cooling circuit and the reheat dehumidification operation in the heating circuit are switched depending on the state according to the required air conditioning load. By switching and operating alternately, dehumidification can be performed while controlling (decreasing, equivalent, increasing) the room temperature. Further, when the refrigerant is sucked into the compressor through the gas-liquid separation container 81, it is possible to store surplus refrigerant, further prevent the liquid back operation of the compressor, and improve the reliability of the compressor. An increase in compressor discharge temperature can be obtained. If the discharge temperature of the compressor rises, the amount of heat exchange in the second indoor heat exchanger 27 can be increased, and a wider heating sensible heat latent heat control range can be obtained.
[0041]
Next, the operation | movement at the time of the air_conditionaing | cooling operation in a present Example is demonstrated. As shown in FIG. 1B, the second flow rate control valve 10 is fully opened, the first flow rate control valve 24 is used as a main pressure reducing device, and the gas bypass on the gas bypass circuit 80 separated by the gas-liquid separation container 82 is used. This is a refrigeration cycle in which the flow rate is controlled by the third flow rate control valve 81. FIG. 5 shows a pressure-enthalpy diagram in the refrigeration cycle during the cooling operation. A to G in FIG. 5 respectively correspond to A to G in the refrigerant circuit in FIG. 1, and the refrigerant flow direction during the cooling operation is indicated by solid arrows in FIG. 1. The refrigerant discharged from the compressor 21 and passing through the four-way valve 22 is condensed from the point A by the outdoor heat exchanger 23 to become the point B, and is depressurized by the first flow rate control valve 24, and then C ′ in the gas-liquid separation container 82. It becomes a point. Of the refrigerant separated in the gas-liquid separation container 82, the gas refrigerant has an H point and the liquid refrigerant has a C point. The liquid refrigerant at point C flows into the first indoor heat exchanger 25 and starts to evaporate. Thereafter, it flows into the second indoor heat exchanger 27 through the second flow rate control valve 10 and evaporates. On the other hand, the gas refrigerant at point H is slightly depressurized by the third flow control valve 81, merges with the gas refrigerant evaporated through the second indoor heat exchanger 27, becomes point G, and the refrigeration cycle sucked into the compressor 21. Become.
[0042]
In FIG. 5, a normal refrigeration cycle that does not use a gas-liquid separation container is shown by dotted lines for comparison. The refrigerant that has been depressurized by the first flow control valve 24 and has reached point C ′ in the gas-liquid separation container flows into the first indoor heat exchanger 25 and starts to evaporate. Thereafter, it flows into the second indoor heat exchanger 27 through the second flow rate control valve 10 and evaporates. And it becomes a refrigerating cycle suck | inhaled by the compressor 21 at G 'point. In FIG. 5, in a normal refrigeration cycle that does not use a gas-liquid separation container, point C and point C ′ shown in FIG.
[0043]
In an actual refrigeration cycle, there is a flow resistance in the refrigerant pipe through which the refrigerant flows. Therefore, a pressure loss as indicated by a point C′-G ′ in FIG. In particular, in a refrigeration cycle incorporating a reheat dehumidifying refrigerant circuit, it is necessary to provide the second flow rate control valve 10 in the indoor unit, and the configuration of the refrigerant piping is complicated, leading to increased pressure loss in the indoor unit. is there. Therefore, if this pressure loss can be reduced, the efficiency of the refrigeration cycle can be dramatically increased, and the energy efficiency of an air conditioner incorporating a reheat dehumidifying refrigerant circuit can be increased. In this refrigeration cycle using a gas-liquid separation container that circulates gas from the upper part from the lower part, the dryness of the two-phase refrigerant at the point C ′ is around 0.2, so that the refrigerant gas and the refrigerant liquid The mass flow ratio is 20% and 80%. Since the refrigerant gas flows through the bypass circuit and flows into the compressor through the gas-liquid separation, the refrigerant flow rate flowing through the point C to the indoor heat exchanger is the total flow rate (= flow rate when the gas-liquid separation container is not used). Of about 80%. The evaporation capacity of this refrigeration cycle is equivalent to that of a refrigeration cycle that does not use a gas-liquid separation container. This is because, in this refrigeration cycle, liquid refrigerant flows into the indoor heat exchanger by gas-liquid separation, so the refrigerant enthalpy difference increases by about 20% compared to the refrigeration cycle that does not use the gas-liquid separation container, and the refrigerant flow rate becomes 80%. However, this is because the evaporation capacities represented by the refrigerant flow rate x the enthalpy difference are almost equal. Accordingly, in this refrigeration cycle, the flow rate of the refrigerant flowing through the indoor heat exchanger is reduced to about 80% of the total flow rate (= the flow rate when the gas-liquid separation container is not used), so that the pressure loss does not use the gas-liquid separation container. Since the pressure is reduced from 60% to 70% (because the pressure loss is proportional to the refrigerant flow approximately 1.75), the efficiency of the refrigeration cycle can be dramatically increased, and a reheat dehumidifying refrigerant circuit is incorporated. It has become possible to increase the energy efficiency of air conditioners.
[0044]
When the refrigerant flow rate is small, the pressure loss in the indoor heat exchanger becomes very small, and therefore the third flow rate control valve 81 may be fully closed in the main refrigeration cycle. In addition, when the refrigerant flow rate changes, such as when the compressor speed changes, the gas bypass flow rate also changes. Therefore, by adjusting the third flow rate control valve 81 valve opening according to the compressor speed, an appropriate gas can be obtained. By ensuring the bypass flow rate, it is possible to realize an operation in which the energy efficiency of the air conditioner is always the highest. Further, if the third flow control valve 81 is constituted by a capillary and an electromagnetic on-off valve (not shown), the cost can be reduced.
[0045]
Next, the operation | movement at the time of the heating defrost operation in a present Example is demonstrated. The first flow control valve 24 and the third flow control valve 81 are fully opened, and the second flow control valve 10 is controlled to be fully closed. The direction of the refrigerant flow in the main refrigeration cycle during the heating and defrosting operation is indicated by a solid line arrow in FIG. The high-temperature and high-pressure refrigerant discharged from the compressor 21 and passing through the four-way valve 22 flows into the outdoor heat exchanger 23 from the point A, and defrosts the frost adhering to the outdoor heat exchanger 23. Thereafter, the refrigeration cycle passes through the first flow rate control valve 24 and the H point of the gas bypass circuit 80 of the gas-liquid separation container 82 through the B point and is sucked into the compressor 21 at the G point.
[0046]
In the conventional refrigeration cycle during the heating and defrosting operation, the high-temperature and high-pressure refrigerant discharged from the compressor 21 and passing through the four-way valve 22 flows into the outdoor heat exchanger 23 from the point A and adheres to the outdoor heat exchanger 23. To defrost. Thereafter, the refrigerant enters the indoor heat exchanger through the point B, the first flow rate control valve 24, and the point C, and passes through the point F and the four-way valve 22 to be a refrigeration cycle sucked into the compressor 21 at the point G. For this reason, the main refrigeration cycle using the gas bypass circuit 80 has a shorter refrigerant path from the discharge of the compressor to the intake of the compressor, and can quickly start the defrosting operation. Time can be shortened and a comfortable air-conditioned space can be obtained. Further, in the conventional heating defrosting operation, since the refrigerant flows into the indoor unit, the indoor heat exchanger acts as an evaporator, and the indoor air is cooled. However, since the refrigerant does not flow into the indoor unit in the refrigeration cycle, heat is not taken from the indoor air, and the indoor environment can be kept comfortable. In addition, the gas-liquid separation container 82 also plays a role of gas-liquid separation and refrigerant storage immediately before suctioning the compressor, thereby preventing the gas-liquid two-phase refrigerant from being sucked into the compressor and preventing damage to the compressor due to liquid back operation. The reliability of the compressor can be improved. Depending on the amount of attached frost, the defrosting operation by the main refrigeration cycle may be performed in the first half of the defrosting start, the defrosting operation by the conventional refrigeration cycle in the second half, or vice versa. Moreover, you may adjust the quantity of the frost which adheres by adjusting heating operation time. The amount of frost can be determined, for example, by attaching a temperature sensor to the indoor heat exchanger, and the lower the evaporation temperature ET measured by this sensor, the more frost can be determined, or the outdoor heat exchanger pressure evaporating pressure or compressor The suction pressure may be used as a judgment material.
[0047]
The control method of this air conditioner is demonstrated using FIG. FIG. 6 is a block diagram of various sensor / actuator control devices used for the refrigerant circuit and operation control of the present invention. The same parts as those in FIG. The structure of the indoor unit 18 is, for example, FIG. Hereinafter, the operation control method of the air conditioner in this embodiment will be described. The air conditioner is provided with a setting device 75 for setting a temperature / humidity environment desired by an indoor resident. In this setting device 75, for example, both temperature and humidity are set, and the resident may input the set values directly from a remote controller attached to the indoor unit 18 as the set temperature and humidity. In addition, an intake air temperature sensor 65 and a humidity sensor 66 for the indoor unit 18 are provided at the suction port for sucking indoor air of the indoor unit 18 in order to detect the temperature and humidity in the room.
[0048]
During the operation of the air conditioner, the difference between the set temperature / humidity and the current indoor suction air temperature / humidity is calculated as a temperature / humidity deviation, and the latent heat and sensible heat, which are indoor air conditioning loads, are calculated by the first calculation device 67 from these deviations. Estimate the load. The actuators of the air conditioner and the compressor 21 are rotated through a signal line 73 so that these deviations are zero or within a predetermined value, that is, in a direction to reduce the difference between the indoor latent heat and the sensible heat air load. The control signal is transmitted to the outdoor fan 61 rotation speed, the indoor fan 63 rotation speed, the throttle opening degree of the first flow rate control valve 24, and the throttle opening degree of the second flow rate control valve 10, and any one of these actuators or these By controlling the combination, the latent heat and sensible heat capacity are adjusted and the air conditioning capacity is exhibited. The control method of these actuators during normal cooling operation and normal heating operation is the same as that of a conventional air conditioner that does not operate with the second flow rate control valve 10 fully opened.
[0049]
The refrigeration cycle during the reheat dehumidifying operation in the cooling circuit is the pressure-enthalpy diagram shown in FIG. 3, and the first indoor heat exchanger capability as a reheater and the second indoor heat exchanger capability as an evaporator. Adjust air flow and control latent heat and sensible heat load to demonstrate air conditioning capability. The increase / decrease in the latent heat capacity is adjusted by increasing / decreasing the capacity of the second indoor heat exchanger serving as an evaporator. On the other hand, since the sensible heat capacity also increases due to the increase in the evaporator capacity, if the sensible heat capacity exceeding the sensible heat load is exhibited, adjust to increase the capacity of the first indoor heat exchanger as the reheater And adjust the sensible heat capacity. A method for controlling each actuator at this time will be described below.
[0050]
For example, as a first example, the information on the indoor latent heat sensible heat load estimated by the first arithmetic unit 67 from the temperature and humidity deviation during the operation of the air conditioner is transmitted via the signal line 73 a in the indoor unit 18. 2, the amount of rotation speed change of the indoor fan motor 64 of the indoor fan 63 is calculated. That is, the information on the current rotational speed of the indoor fan 63 is transmitted from the indoor fan motor 64 rotational speed control device 69 to the second arithmetic device 74 via the signal line 73a. At this time, the value of the latent heat sensible heat load input by an input device (not shown) such as a remote controller is compared with the detected current latent heat sensible heat load in the room, and the set temperature and humidity are compared with the current value. If the input value of the input latent heat sensible heat load is large, the indoor fan motor 64 rotational speed is calculated as a value larger than the current value, and information on the new indoor fan motor 64 rotational speed is obtained via the signal line 73a. It is transmitted to the rotational speed control device 69 and controlled as a new indoor fan motor 64 rotational speed. In this way, the latent heat sensible heat capacity is increased by increasing the air flow rate of the indoor fan 63, and control is performed so that the input value matches the current value.
[0051]
For example, as a second example, the information about the latent heat sensible heat load in the room estimated by the first arithmetic unit 67 from the temperature / humidity deviation during the operation of the air conditioner is transmitted via the signal line 73a to the second arithmetic unit. 74, the amount of rotation speed change of the outdoor fan motor 62 of the outdoor fan 61 is calculated. In other words, the information on the current rotational speed of the outdoor fan 62 is secondly transmitted from the outdoor fan motor 62 rotational speed control device 68 via the signal line 73 c in the outdoor unit 17 and the signal line 73 b connecting the outdoor unit 17 and the indoor unit 18. As the amount of reheat heat exchange in the room is increased, the outdoor fan motor 62 rotational speed is calculated to be smaller than the current value, and information on the new outdoor fan motor 62 rotational speed is obtained. The signal is transmitted to the outdoor fan motor rotational speed control device 68 via the signal lines 73b and 73c, and is controlled as a new outdoor fan motor 62 rotational speed. At this time, the condensation capacity in the outdoor space decreases due to the decrease in the air flow rate of the outdoor fan 61, the condensation capacity in the first indoor heat exchanger 25 relatively increases, and the reheat heat exchange amount in the room increases. The amount of sensible heat exchange can be controlled.
[0052]
Further, for example, as a third example, information on the latent heat sensible heat load in the room estimated by the first arithmetic unit 67 from the temperature and humidity deviation during the operation of the air conditioner is transmitted via the signal line 73a to the second arithmetic unit. 74, the amount of change in the rotation speed of the compressor 21 is calculated. That is, the information on the current compressor speed 21 is transmitted from the compressor speed controller 70 to the second arithmetic unit 74 via the signal lines 73c and 73b, and the latent heat sensible heat exchange amount in the room is calculated. When it is desired to increase the value, the compressor 21 speed is calculated as a value larger than the current value, and information on the new compressor 21 speed is transmitted to the compressor speed controller 70 via the signal lines 73b and 73c. The compressor 21 is controlled as the number of rotations. At this time, in the refrigeration cycle in the pressure-enthalpy diagram shown in FIG. 3, the amount of latent heat sensible heat exchange in the room increases due to an increase in the refrigerant flow rate.
[0053]
For example, as a fourth example, the information about the latent heat sensible heat load in the room estimated by the first arithmetic unit 67 from the temperature / humidity deviation during the operation of the air conditioner is transmitted via the signal line 73a to the second arithmetic unit. 74, the amount of change in the opening of the first flow control valve 24 is calculated. That is, the current valve opening information of the first flow control valve 24 is transmitted from the first flow control valve 24 valve opening control device 71 to the second arithmetic device 74 via the signal lines 73c and 73b. When it is desired to increase the sensible heat exchange amount in the room, the valve opening of the first flow control valve 24 is calculated as a value smaller than the current value, and information on the new valve opening of the first flow control valve 24 is a signal line. It is transmitted to the valve opening degree control device 71 of the first flow rate control valve 24 via 73b, 73c, and is controlled as the new valve opening degree of the first flow rate control valve 24. At this time, due to a decrease in the opening degree of the first flow control valve 24, the pressure between the points C and D shown in FIG. 3 decreases, the condensation temperature in the first indoor heat exchanger 25 decreases, and the reheat heat The amount of exchange decreases, and the amount of sensible heat exchange in the room is adjusted.
[0054]
For example, as a fifth example, the information about the latent heat sensible heat in the room estimated by the first arithmetic unit 67 from the temperature / humidity deviation during the operation of the air conditioner is transmitted via the signal line 73a to the second arithmetic unit. 74, the amount of change in the opening of the second flow control valve 10 is calculated. That is, the current valve opening information of the second flow rate control valve 10 is transmitted from the second flow rate control valve 10 valve opening degree control device 72 to the second arithmetic unit 74 via the signal line 73a. As the latent heat sensible heat exchange amount increases, the opening degree of the second flow rate control valve 10 is calculated as a value smaller than the current value, and the information of the new second flow rate control valve 10 becomes the signal line 73a. Is transmitted to the second flow rate control valve 10 valve opening degree control device 72 and is controlled as the valve opening degree of the new second flow rate control valve 10. At this time, due to the decrease in the valve opening degree of the second flow control valve 10, the pressure between the points E and F shown in FIG. 3 is decreased, and the evaporation temperature in the second indoor heat exchanger 27 is decreased. Adjust the amount of latent heat sensible heat exchange.
[0055]
In addition, although the control method of each of the five types of actuators has been described as the first to fifth examples described above, these actuators can be controlled individually based on various types of information, but specific actuators among the five types can be combined. Control may be performed, another actuator may be controlled based on specific actuator information of the five types, or priority may be given to each actuator. For example, if the rotational speed of the compressor 21 is increased while the air flow rate of the indoor fan 63 is small, the latent heat sensible heat exchange amount increases, but the evaporation temperature decreases too much to 0 ° C. or less, and the drain water freezes. The indoor unit 18 may be damaged. At this time, a lower limit value is provided for the air flow rate of the indoor fan 63, and an upper limit value is provided for the rotational speed of the compressor 21 when the rotational speed of the indoor fan motor 64 corresponding to the air flow rate is less than a certain value. If the necessary amount of latent heat sensible heat exchange cannot be obtained, the number of rotations of the indoor fan motor 64 is increased to increase the air flow of the indoor fan 63, and the evaporation temperature may be controlled to be 0 ° C. or higher. For example, when the latent heat sensible heat exchange amount is controlled only by the control devices 69 and 72, it is not necessary to transmit information between the indoor unit 18 and the outdoor unit 17, and a signal between the indoor unit 18 and the outdoor unit 17 is eliminated. The line 73b becomes unnecessary, and it is possible to prevent malfunction due to disconnection or connection failure of the signal line 73b. FIG. 6 shows an example in which the second arithmetic unit 74 is installed in the indoor unit 18, but it may be installed in the outdoor unit 17. At this time, for example, in the case where the latent heat sensible heat exchange amount is controlled only by the outdoor fan control device 68, the compressor control device 70 and the second flow rate control valve control device 72, the first arithmetic device 67 estimates it. The information on the latent heat sensible heat load in the room, the current rotational speed of the indoor fan 63, and the information on the valve opening of the second flow control valve 10 are sent to the second arithmetic unit via signal lines 73a and 73b. 74, the control signal is transmitted through 73c, and the control devices 68 and 70 and 72 operate. That is, since there is no return of the control signal from the outdoor unit 17 to the indoor unit 18, for example, the resident can freely select the air flow rate of the indoor fan 63 regardless of the operating state of the actuator in the indoor unit 18. However, the latent heat sensible heat capacity in the room can be adjusted.
[0056]
When the temperature / humidity deviation is zero or within a predetermined value by the control method described above, the current operation may be continued. As described above, in this embodiment, by controlling various actuators according to the latent heat sensible heat load during the reheat dehumidifying operation in the cooling circuit, the temperature and humidity environment in the room is optimized according to the preference of the resident. 2 and the structure of the indoor unit 18 is implemented as shown in FIG. 2, the blown-out air is also free from temperature unevenness and a comfortable indoor environment can be obtained. In addition, if a porous permeable material is used for the second flow control valve 10, the refrigerant flow noise is reduced, and a more comfortable indoor environment is achieved.
[0057]
On the other hand, the refrigeration cycle during the reheat dehumidifying operation in the heating circuit is the pressure-enthalpy diagram shown in FIG. 4, and the capacity of the second indoor heat exchanger 27 serving as a reheater and the first indoor heat exchange serving as an evaporator. The capacity of the vessel 25 is adjusted and the latent heat and sensible heat load are controlled to exert the air conditioning capacity. The increase / decrease in the latent heat capacity is adjusted by increasing / decreasing the capacity of the first indoor heat exchanger 25 serving as an evaporator. On the other hand, since the sensible heat capacity for cooling increases due to the increase in the evaporator capacity, if the sensible heat capacity exceeding the sensible heat load is exhibited, the capacity of the second indoor heat exchanger 27 serving as a reheater is increased. Adjust the sensible heat capacity to heat and cool. The evaporation temperature detected by the temperature sensor 92 provided in the first indoor heat exchanger 25 is transmitted to the computing device 78. Then, comparison is made with temperature information detected by the intake air temperature sensor 65 and the humidity sensor 66 transmitted from the signal line, and it is calculated whether the evaporation temperature is equal to or lower than the dehumidifying temperature. For example, the evaporation temperature may be equal to or lower than the dew point temperature calculated from the intake air temperature and humidity. In order to realize this state, the air volume of the indoor fan 63, the second flow control valve 10 opening degree, and the compressor 21 rotation speed are controlled. When it is desired to lower the evaporation temperature and increase the amount of latent heat exchange, control such as lowering the air flow rate of the indoor fan 63, reducing the opening of the second flow control valve 10 and increasing the compressor 21 rotational speed capability, etc. Good. A method for controlling each actuator at this time will be described below.
[0058]
For example, as a first example, the information on the indoor latent heat sensible heat load estimated by the first arithmetic unit 67 from the temperature and humidity deviation during the operation of the air conditioner is transmitted via the signal line 73 a in the indoor unit 18. 2, the amount of rotation speed change of the indoor fan motor 64 of the indoor fan 63 is calculated. That is, the information on the current rotational speed of the indoor fan 63 is transmitted from the indoor fan motor 64 rotational speed control device 69 to the second arithmetic device 74 via the signal line 73a. At this time, the detected value of the latent heat sensible heat load in the room is compared with the value of the latent heat sensible heat load input by an input device (not shown) such as a remote controller, and the input value is larger than the current value. For example, the rotational speed of the indoor fan motor 64 is calculated as a value larger than the current value, and information on the new rotational speed of the indoor fan motor 64 is transmitted to the indoor fan motor rotational speed control device 69 via the signal line 73a. The fan motor 64 is controlled as the number of rotations. In this way, the latent heat sensible heat capacity is increased by the increase in the blowing amount of the indoor fan 63.
[0059]
For example, as a second example, the information about the latent heat sensible heat load in the room estimated by the first arithmetic unit 67 from the temperature / humidity deviation during the operation of the air conditioner is transmitted via the signal line 73a to the second arithmetic unit. 74, the amount of change in the rotation speed of the compressor 21 is calculated. That is, the information on the current compressor speed 21 is transmitted from the compressor speed controller 70 to the second arithmetic unit 74 via the signal lines 73c and 73b, and the latent heat sensible heat exchange amount in the room is calculated. When it is desired to increase the value, the compressor 21 speed is calculated as a value larger than the current value, and information on the new compressor 21 speed is transmitted to the compressor speed controller 70 via the signal lines 73b and 73c. The compressor 21 is controlled as the number of rotations. At this time, in the refrigeration cycle in the pressure-enthalpy diagram shown in FIG. 4, the amount of latent heat sensible heat exchange in the room increases due to an increase in the refrigerant flow rate.
[0060]
Further, for example, as a third example, information on the latent heat sensible heat load in the room estimated by the first arithmetic unit 67 from the temperature and humidity deviation during the operation of the air conditioner is transmitted via the signal line 73a to the second arithmetic unit. 74, the amount of change in the opening of the second flow control valve 10 is calculated. That is, the current valve opening information of the second flow rate control valve 10 is transmitted from the second flow rate control valve 10 valve opening degree control device 72 to the second arithmetic unit 74 via the signal line 73a. As the latent heat sensible heat exchange amount increases, the opening degree of the second flow rate control valve 10 is calculated as a value smaller than the current value, and the information of the new second flow rate control valve 10 becomes the signal line 73a. Is transmitted to the second flow rate control valve 10 valve opening degree control device 72 and is controlled as the valve opening degree of the new second flow rate control valve 10. At this time, as the valve opening degree of the second flow rate control valve 10 decreases, the pressure at the point D shown in FIG. 4 decreases, the evaporation temperature in the first indoor heat exchanger 25 decreases, and the latent heat in the room appears. Adjust the amount of heat and heat exchange.
[0061]
Although the control methods for each of the three types of actuators have been described as the first to third examples, these actuators may be controlled individually based on various information, or may be controlled in combination with specific actuators. Another actuator may be controlled based on specific actuator information among the three types, or each actuator may be prioritized and controlled. For example, if the rotational speed of the compressor 21 is increased while the air flow rate of the indoor fan 63 is small, the latent heat sensible heat exchange amount increases, but the evaporation temperature decreases too much to 0 ° C. or less, and the drain water freezes. The indoor unit 18 may be damaged. At this time, a lower limit value is provided for the air flow rate of the indoor fan 63, and an upper limit value is provided for the rotational speed of the compressor 21 when the rotational speed of the indoor fan motor 64 corresponding to the air flow rate is less than a certain value. If the necessary amount of latent heat sensible heat exchange cannot be obtained, the number of rotations of the indoor fan motor 64 is increased to increase the air flow of the indoor fan 63, and the evaporation temperature may be controlled to be 0 ° C. or higher. For example, when the latent heat sensible heat exchange amount is controlled only by the control devices 69 and 72, it is not necessary to transmit information between the indoor unit 18 and the outdoor unit 17, and a signal between the indoor unit 18 and the outdoor unit 17 is eliminated. The line 73b becomes unnecessary, and it is possible to prevent malfunction due to disconnection or connection failure of the signal line 73b. FIG. 6 shows an example in which the second arithmetic unit 74 is installed in the indoor unit 18, but it may be installed in the outdoor unit 17. At this time, for example, when the latent heat sensible heat exchange amount is controlled only by the control devices 68, 70 and 72, information on the indoor latent heat sensible heat load estimated by the first arithmetic device 67, Information on the current rotational speed and the valve opening degree of the second flow rate control valve 10 is transmitted to the second arithmetic unit 74 via the signal lines 73a and 73b, and a control signal is transmitted and controlled via 73c. Devices 68 and 70 and 72 operate. In other words, since there is no return of the control signal from the outdoor unit 17 to the indoor unit 18, no matter what the operating condition of the actuator in the indoor unit 18 is (for example, the resident can freely select the air volume of the indoor fan 63). However, the latent heat sensible heat capacity in the room can be adjusted.
[0062]
When the temperature / humidity deviation is zero or within a predetermined value by the control method described above, the current operation may be continued. As described above, in this embodiment, by controlling various actuators according to the latent heat sensible heat load during the reheat dehumidifying operation in the heating circuit, the temperature and humidity environment in the room is optimized according to the resident's preference. 2 and the structure of the indoor unit 18 is implemented as shown in FIG. 2, the blown-out air is also free from temperature unevenness and a comfortable indoor environment can be obtained. In addition, if a porous permeable material is used for the second flow control valve 10, the refrigerant flow noise is reduced, and a more comfortable indoor environment is achieved.
[0063]
In the above description, the sensible heat load during the reheat dehumidifying operation in the heating circuit has been described as an example of cooling. However, for the sensible heat load in the case of heating, the heat exchange amount in the second indoor heat exchanger 27 is increased or decreased. What is necessary is just to implement | achieve with the control method mentioned above. FIG. 7 shows an operation map of the capability control range and operation switching. In the heating operation, the latent heat capacity is 0, and the sensible heat capacity for heating can be controlled. The cooling operation is started when the latent heat sensible heat load detected by the above-described latent heat sensible heat load detection device corresponds to the latent heat sensible heat capacity control range set in the cooling operation. At this time, the sensible heat load and the latent heat load to be cooled are larger than those in other operations. And when cooling operation is continued, the latent heat sensible heat load detected by the above-mentioned latent heat sensible heat load detection device becomes smaller than the latent heat sensible heat capacity control range set in the cooling operation and becomes a preset range, Switch operation to reheat dehumidification operation in cooling circuit. When the latent heat sensible heat load further decreases and reaches a preset range, the operation is switched to the reheat dehumidification operation in the heating circuit.
[0064]
The operation switching method from the cooling operation has been described above, but the first operation method is determined according to the latent heat sensible heat load detected by the latent heat sensible heat load detection device when the air conditioner starts operation, and then When detecting the latent heat and sensible heat load fluctuation, and selecting the appropriate operation method from the preset latent heat sensible heat capacity control range map as shown in FIG. 7, and switching the range according to the load fluctuation situation It automatically switches four-way valves. This switching can be performed freely, or may be performed after the compressor is once stopped. If there is a loud noise during the switching operation, the compressor is stopped and switched, but if a control valve using foam metal, which will be described later, is used, the generation of noise can be suppressed, so that it can be switched without stopping.
[0065]
Moreover, since the reheat dehumidification operation in the heating circuit can exhibit the sensible heat capability of heating while securing the latent heat capability, for example, the dehumidification can be performed in an air conditioning condition where the outside temperature is low but the relative humidity is high. In other words, it can be dehumidified under conditions of high relative humidity, such as during snowfall or during winter, but it can be dehumidified under conditions of high relative humidity, thus preventing condensation on windows and the like. An unpleasant phenomenon such as wetting can be avoided.
[0066]
By combining the capacity control range in the cooling operation, the reheat dehumidification operation control range in the cooling circuit, the reheat dehumidification operation control range in the heating circuit, and the capacity control range in heating, including cooling and heating A wide latent heat sensible heat capacity control range can be achieved.
[0067]
On the other hand, the refrigeration cycle during the operation using the cooling gas-liquid separation container is the pressure-enthalpy diagram shown in FIG. The control method of each actuator at this time will be described below particularly when R32 is used as the refrigerant.
[0068]
R32 refrigerant, for example, has a compressor discharge temperature higher by 10 ° C. or more than R410A refrigerant, has a problem in reliability, such as rapid deterioration of refrigeration oil in the compressor and poor lubrication of the compressor sliding portion. It is necessary to control the actuator so that the compressor discharge temperature does not rise more than necessary. In the present invention, the discharge temperature detected by the temperature sensor 93 provided in the compressor discharge as shown in FIG. Further, the evaporative heat exchanger outlet superheat degree detected by the sensor 91 provided in the second indoor heat exchanger 27 is transmitted to the arithmetic device 77. The sensor 91 can be calculated from, for example, the evaporating heat exchanger outlet temperature and the evaporating heat exchanger outlet pressure, or can be calculated from the difference between the evaporating heat exchanger intermediate temperature and the evaporating heat exchanger outlet temperature. In order to maximize the efficiency of the heat exchanger of the evaporator, it is necessary to control the degree of superheat of the outlet of the evaporation heat exchanger to about 0 to 3 ° C. For this purpose, the rotation speed of the compressor 21, the opening degree of the first flow rate control valve 24, the air flow rate of the indoor fan 63, and the outdoor fan 61 are adjusted so that the detected superheat degree of the evaporative heat exchanger outlet falls within the range of the value. What is necessary is just to control a ventilation volume.
[0069]
However, if the superheat degree of the evaporative heat exchanger outlet is controlled to about 0 to 3 ° C., the suction superheat level will surely rise above this value (3 ° C.) in the compressor suction, and the compressor discharge temperature may become higher than necessary. is there. Therefore, the intake air temperature sensor 65 in the room, the outside air temperature sensor 94 through the arithmetic unit 95, the rotation speed of the compressor 21, the opening degree of the first flow rate control valve 24, the air volume of the indoor fan 63, the air volume of the outdoor fan 61 If the value of the compressor discharge temperature sensor 93 exceeds the upper limit value of the compressor discharge temperature calculated by the calculation device 74 based on the information, the third flow control valve 81 is connected via the calculation control device 76. And the saturated gas or the gas-liquid two-phase refrigerant may be injected from the gas-liquid separation container 82 to the point G on the refrigerant circuit through the gas bypass circuit 80. Thus, the opening degree of the third flow rate control valve 81 is adjusted to a value corresponding to the compressor discharge refrigerant temperature, the compressor suction refrigerant superheat degree, and the compressor discharge refrigerant superheat degree. As a result, the compressor discharge temperature can be lowered while maintaining the evaporative heat exchanger outlet superheat degree at which the heat exchanger efficiency of the evaporator is maximized, and the energy efficiency of the air conditioner is made high and reliable. It is also possible to improve the performance. The indoor heat exchanger outlet refrigerant superheat degree may be detected by a value corresponding to this. For example, the refrigerant superheat degree may be calculated by measuring the indoor heat exchanger outlet temperature and the indoor heat exchanger outlet pressure, or may be estimated from the indoor heat exchanger intermediate temperature and the indoor heat exchanger outlet temperature. . Moreover, what is necessary is just to detect the value corresponding to this also about the compressor discharge refrigerant | coolant temperature. For example, it may be estimated from the compressor suction refrigerant temperature, the compressor suction refrigerant superheat degree, the compressor discharge refrigerant superheat degree, and the like.
[0070]
In addition to the structure described above as the first embodiment of the present invention, the indoor heat exchanger is arranged in an arc shape, or a multistage bending structure in which the heat exchanger is divided into a larger number than in FIG. The object of the present invention can be more easily achieved by devising such as thermally blocking between, for example, cutting the heat transfer fins 28 between the stages of the heat transfer tubes 11 to prevent heat conduction in the fins. The
[0071]
As still another example according to the first embodiment of the present invention, as shown in FIG. 8, during reheat dehumidification operation in the cooling circuit, heat is generated upstream of the refrigerant flow of the heat exchanger serving as the reheater. A supplementary heat exchanger 14 that is shut off may be provided. Since this auxiliary heat exchanger 14 functions as a reheater during the reheat dehumidifying operation in the cooling circuit, the reheat heat exchanger capacity is expanded and the reheat heat exchange amount is increased, thereby preventing a decrease in room temperature. However, it is possible to increase the capacity control range for reheat dehumidification. Further, when the capacity of the reheat heat exchanger is simply increased, the size of the indoor unit 18 is increased. However, when installed as in the present embodiment, the void space in the indoor unit 18 can be used effectively, and the indoor unit 18 Can also be made compact.
[0072]
Next, an example in which the auxiliary heat exchanger 14 is provided will be described with reference to FIG. In FIG. 8, the indoor heat exchanger during heating operation is a condenser, but the auxiliary heat exchanger 14 is installed on the downstream side of the indoor heat exchanger. In order to improve the amount of condensation heat exchange, it is necessary to increase the refrigerant enthalpy by taking a sufficient degree of refrigerant supercooling at the outlet of the condenser. However, in the supercooling region, the refrigerant is in a liquid state and the refrigerant temperature is lower than the condensation temperature. For this reason, in the supercooling zone, the refrigerant flow rate in the heat transfer tube is increased to increase the refrigerant heat transfer rate, and the heat transfer tube in the supercooling zone is installed on the windward side of the air flow so that the temperature before the heat exchange is relatively high. It is necessary to exchange heat with low air to improve the amount of condensation heat exchange. In addition, it is necessary to reduce the amount of heat that does not contribute to air conditioning by heat conduction through the heat transfer fins and heat exchange by thermally blocking the supercooled portion from the saturated portion. Furthermore, it is necessary to arrange the heat transfer tubes in the high-temperature gas refrigerant region at the condenser inlet as a counterflow with air. In FIG. 8, the auxiliary heat exchanger 14 is installed at a portion that is on the outlet side of the condenser during heating operation, and is installed at the upstream side of the front upper oblique portion 1 heat exchanger, and the refrigerant flow path One system. Therefore, as described above, the refrigerant flow rate in the heat transfer tube is sufficiently high, the refrigerant heat transfer coefficient is high, the temperature difference from the air is sufficient, and sufficient performance as a supercooling heat exchanger can be exhibited. it can. Moreover, since the auxiliary heat exchanger 14 is installed separately from the front upper-stage oblique portion 1 heat exchanger and is cut off thermally, it does not contribute to air conditioning in which heat is transferred between the heat transfer fins 28 to exchange heat. The amount of heat can be reduced, and the heat exchange performance can be improved. Furthermore, in FIG. 8, a pipe through which the high-temperature gas refrigerant serving as the condenser inlet during heating operation flows is installed on the downstream side of the air flow and flows opposite to the low-temperature air. Can be improved.
[0073]
FIG. 8 shows a case where the refrigerant flow path of the auxiliary heat exchanger 14 serving as the supercooling heat exchanger is one system and the refrigerant flow path using the high-temperature gas refrigerant serving as the condenser inlet is two systems. The number of channels should be set to an optimum value so that the effect on the heat exchange performance is maximized in view of the refrigerant heat transfer coefficient including the cooling operation and the refrigerant pressure loss. The number is set. That is, if the heat transfer tube diameter of the auxiliary heat exchanger 14 is made smaller than the heat transfer tube diameter of the main indoor heat exchanger, the refrigerant flow rate in the heat transfer tube is sufficiently high, the refrigerant heat transfer rate is increased, and heat exchange is further performed. The amount can be improved.
[0074]
The operation when using the cooling gas-liquid separation container of this example will be described. During the cooling operation, the liquid refrigerant flows into the auxiliary heat exchanger 14. In a conventional refrigerant circuit without a gas-liquid separation container, a gas-liquid two-phase refrigerant flows into the auxiliary heat exchanger 14. Since the liquid refrigerant has a lower heat transfer coefficient than the gas-liquid two-phase refrigerant, the amount of heat exchange may be reduced. In this embodiment, in order to solve this drawback, by making the refrigerant flow path of the auxiliary heat exchanger 14 as one system, the refrigerant heat transfer rate can be increased by increasing the refrigerant flow rate in the heat transfer tube, The amount of heat exchange for evaporation has been improved. Although there is a concern about an increase in refrigerant pressure loss due to a single refrigerant flow path, the refrigerant flowing through the auxiliary heat exchanger 14 has a low dryness, resulting in a pressure loss almost equal to that of the liquid single phase, which is excessive. There is no significant increase in pressure loss.
[0075]
Further, in this embodiment, the auxiliary heat exchanger 14 is arranged on the upstream side of the air flow 9a of the front upper oblique portion 1 heat exchanger having the highest passing air speed, but there is a possibility that the ventilation resistance increases and the air volume decreases. The auxiliary heat exchanger 14 needs to have a small ventilation resistance. In other words, the fin pitch of the heat transfer fins is enlarged, the heat transfer fin width is reduced, or the heat transfer fins provided to improve the heat transfer performance in the indoor heat exchanger are not used. May be.
[0076]
In addition, when the space for installing the auxiliary heat exchanger 14 cannot be obtained by any means, as shown in FIG. 9, the heating outlet flow path has one system, and the front row side heat transfer tube and the rear row of the front upper oblique portion 1 heat exchanger. A notch 20 that thermally shuts off the heat transfer tubes may be provided between the heat transfer fins 28 of the side heat transfer tubes. Thereby, the heat quantity which does not contribute to the air conditioning which conducts heat by conducting heat through the heat transfer fins can be reduced, and the heat exchange quantity can be improved. Moreover, if the outlet channel for heating is one system and the heat transfer tube diameter is made smaller than the heat transfer tube diameter of the main indoor heat exchanger, the refrigerant flow rate in the heat transfer tube becomes sufficiently fast, and the refrigerant heat transfer coefficient increases. Further, the amount of heat exchange can be improved.
[0077]
In the air conditioner of the present invention, characteristics when the flow control valve having the structure shown in FIG. 10 is used as the second flow control valve 10 disposed in the indoor unit 18 will be described below. The structure and operation of this flow control valve are as follows.
[0078]
In FIG. 10, 31 in the second flow control valve 10 is connected to the first indoor heat exchanger 25 via the first flow path, and 32 is connected to the second indoor heat exchanger 27 via the second flow path. 33 is a main valve seat in which the refrigerant flow path is open, and 34 is a main valve body that slides up and down along the inner surface of the main body of the second flow rate control valve 10. It is composed. 35 is an electromagnetic coil for driving the main valve body 34, and energizes and shuts off the electromagnetic coil 35 on the basis of a command from a control unit (not shown) to open and close the main valve body 34. The main valve body 34 is formed of a porous permeable material communicating with the refrigerant flow direction. Specifically, a metal powder, a ceramic powder, a foamed metal, a foamed resin, or the like is put into a mold and subjected to pressure molding, and a temperature below the melting point. It is composed of baked and hardened. When the electromagnetic coil 35 is energized, the main valve body 34 rises, leaves the main valve seat 33, and the refrigerant flows through the first flow path 31 and the second flow path 32 without flow resistance. When the electromagnetic coil 35 is energized again, the main valve body 34 descends, comes into close contact with the main valve seat 33, and the first flow path 31 and the second flow path through the porous permeable material constituting the main valve body 34. 32 communicates.
[0079]
Next, the operation of the air conditioner using the flow control valve shown in FIG. 10 will be described. During normal cooling operation, the refrigerant flows in the direction indicated by the solid line arrow in FIG. 1, and during normal heating operation, the refrigerant flows in the direction indicated by the dotted line arrow in FIG. At this time, the flow rate of the refrigeration cycle is adjusted by the first flow rate control valve 24, and the second flow rate control valve 10 moves up from the main valve seat 33 as shown in FIG. The first flow path 31 and the second flow path 32 communicate with each other, and the refrigerant flows without flow resistance. Therefore, the air conditioner can be operated without a decrease in capacity or efficiency due to an increase in refrigerant pressure loss.
[0080]
On the other hand, during the reheat dehumidification operation in the cooling circuit, the opening degree of the first flow rate control valve 24 is opened, and the refrigeration cycle uses the second flow rate control valve 10 as a main pressure reducing device. The pressure-enthalpy diagram in the refrigeration cycle during the reheat dehumidifying operation in this cooling circuit is shown in FIG. That is, as shown in FIG. 10 (b), the second flow control valve 10 is lowered through the porous permeable material constituting the main valve body 34 as the main valve body 34 descends and comes into close contact with the main valve seat 33. The first flow path 31 and the second flow path 32 communicate with each other, and the porous permeable material acts as a flow resistor.
[0081]
At this time, since the porous permeable material is used as the flow resistor of the second flow control valve 10, the refrigerant flow noise when the gas-liquid two-phase refrigerant or liquid refrigerant passes through the second flow control valve 10 is greatly increased. Can be reduced. For example, in the conventional second flow control valve 10 shown in FIG. 19, the orifice of the gap between the main valve seat 33 and the main valve body 34 acts as a flow resistor as shown in FIG. A very loud refrigerant flow noise is generated when the refrigerant passes. In particular, as shown in FIG. 3, when the refrigerant dryness is small and the flow mode of the gas-liquid two-phase refrigerant is a slag flow, such as the point D at the inlet of the second flow control valve 10, a loud refrigerant flow noise is generated. It has been known. The cause of the generation of the refrigerant flow noise is that the vapor refrigerant intermittently flows in the flow direction, and the vapor slag or vapor bubbles collapses when vapor slag or vapor bubbles larger than the orifice diameter pass through the orifice portion. As a result, vibration is generated and sound propagates through the main valve seat 33 and the like in FIG. 19 or vapor refrigerant and liquid refrigerant having different speeds alternately pass through the orifice portion, resulting in pressure fluctuation. This is because sound propagates through the main valve seat 33 and the like.
[0082]
On the other hand, in the second flow rate control valve 10 in the present embodiment shown in FIG. 10B, the gas-liquid two-phase refrigerant and the liquid refrigerant are fine in the main valve body 34 formed of the porous permeable material. The pressure is reduced through a myriad of vents. Therefore, steam slag and steam bubbles do not collapse. Further, since the vapor refrigerant and the liquid refrigerant pass through the throttle portion at the same time, they are mixed very well so that the speed of the refrigerant does not fluctuate and the pressure does not fluctuate. The conventional second flow rate control valve 10 shown in FIG. 19 has one flow path, but the porous permeation material has a complicated internal flow path, and the small holes serve as flow resistors, The pressure drops. The porous permeable material has an effect of making the pressure fluctuation constant while the flow velocity fluctuation is repeated as pressure fluctuation inside the porous permeable material and partially converted into thermal energy. This is generally referred to as a sound absorption effect and is considered to be a mechanism for eliminating sound. In addition, since the flow rate of the refrigerant is sufficiently reduced and constant in the porous permeable material, there is no effect that vortices are generated in the flow at the porous permeable material outlet and the jet noise is reduced. For this reason, the refrigerant flow noise generated from the second flow control valve 10 can be greatly reduced.
[0083]
The flow rate characteristic of the second flow control valve 10 during the reheat dehumidification operation (relationship between the refrigerant flow rate and the refrigerant pressure loss) is the size of the porous permeable material used for the main valve body 34 and the flow path length through which the refrigerant passes. And it can adjust by adjusting the porosity (gap volume per unit volume) of a porous permeable material. That is, when flowing a certain refrigerant flow rate with a small pressure loss, the pore size of the porous permeable material is increased (for example, the element of the porous permeable material is increased), the flow path length is shortened (the valve body is For example, a porous transmission material having a large porosity may be used. On the other hand, when flowing a refrigerant flow with a large pressure loss, the pore size of the porous permeable material is reduced (for example, the element of the porous permeable material is reduced), or the flow path length is increased (valve For example, a porous permeable material having a low porosity may be used. The pore diameter of the porous permeable material used for the main valve body 34 and the shape of the valve body are optimally designed when designing the air conditioner.
[0084]
This eliminates the need for measures such as wrapping a sound insulating material or a vibration damping material around the second flow control valve 10 that has been necessary in conventional air conditioners, and reduces costs, and further eliminates the need for these other materials. Therefore, the recyclability of the air conditioner is also improved.
[0085]
In addition, although the operation | movement at the time of the reheat dehumidification operation in a cooling circuit was described above, the same effect is also obtained at the time of the dehumidification operation in the heating circuit where the refrigerant flow direction is reversed (refrigeration cycle operation state shown in FIG. 4). Is obtained.
[0086]
Moreover, even if the flow rate control valve using the porous permeable material described above is used for the first flow rate control valve 24, a similar effect such as reducing the refrigerant flow noise can be obtained. Even in the control valve for adjusting the opening degree, the flow rate can be controlled by adjusting the gap between the main valve 34 and the main valve seat 33. In addition, the generation of the refrigerant flow noise caused by the gas-liquid two-phase refrigerant described above is not limited to the air conditioner, and is a general refrigeration cycle of a cooling / heating air conditioner including a refrigerator. The flow control valve shown in the embodiment can be applied widely to such a refrigeration cycle in general, and similar effects such as reducing refrigerant flow noise can be obtained.
[0087]
Embodiment 2. FIG.
An air conditioner according to a second embodiment of the present invention will be described. FIG. 11 is a refrigerant circuit of the present invention, and the same parts as those in FIG. The structure of the indoor unit 18 is, for example, FIG. Each operation mode described in the first embodiment can be performed in the same manner. At this time, a throttle device 36 using a porous permeable material is provided in the pipe at the second flow rate control valve position between the first indoor heat exchanger 25 and the second indoor heat exchanger 27 arranged in the indoor unit 18, In parallel with this, an electromagnetic on-off valve 37 is provided on the refrigerant flow path that bypasses the expansion device 36. That is, the expansion device 36 and the electromagnetic on-off valve 37 serve as the second flow control valve 10 in FIG. An example of the structure of the diaphragm 36 is shown in FIG. The main body of the expansion device 36 is constituted by a cylindrical container, and has a structure in which foam metal 38a, 38b, which is an example of the porous permeable material shown in FIG. As another example of the porous permeable material, any metal powder, ceramic powder, sintered metal, foamed resin, and the like may be put into a mold, press-molded, and baked at a temperature below the melting point. And both ends of the foam metal 38a, 38b are fixed by a fixing jig 40, and a pipe 41 is connected. Hereinafter, operations of the throttle device 36 and the electromagnetic on-off valve 37 will be described.
[0088]
In this embodiment, except for the reheat dehumidifying operation, the electromagnetic on-off valve 37 is opened as shown in FIG. At this time, since the flow resistance of the electromagnetic opening / closing valve 37 is smaller than the flow resistance of the expansion device 36, the refrigerant bypasses the expansion device 36 and flows through the electromagnetic opening / closing valve 37 with almost no resistance. Therefore, the air conditioner can be operated without a decrease in capacity or efficiency due to an increase in refrigerant pressure loss. On the other hand, during the reheat dehumidifying operation, the electromagnetic on-off valve 37 is closed and the refrigerant is depressurized through the orifice 39. At this time, the gas-liquid two-phase refrigerant flowing in the direction of the solid line arrow in FIG. At this time, the foam metal 38a uniformly mixes the gas-liquid two-phase refrigerant flowing into the orifice 39, and the foam metal 38b functions to uniformly mix the gas-liquid two-phase refrigerant flowing out of the orifice 39. Can be prevented.
[0089]
In FIG. 12, the foam metal 38 of the throttling device 36 has a structure in which the orifice 39 is sandwiched. However, the orifice 39 has a small flow resistance only with the foam metal 38 and can be used together when a predetermined pressure reducing action is obtained. If the flow resistance can be adjusted by adjusting the size of the porous permeable material, the length of the flow path through which the refrigerant passes, and the porosity of the porous permeable material (gap volume per unit volume) Alternatively, the foam metal 38 alone may be used as a flow resistance. Further, when the orifice 39 is used in combination, the sintered metal 38 is arranged only on the refrigerant flow upstream side 38a or the refrigerant flow downstream side 38b of the orifice 39. Generation of refrigerant flow noise can be prevented. In addition, since a microfluid (dust, deteriorated material, etc.) called sludge flows in the refrigerant circuit, if the porosity of the porous permeable material of the foam metal 38 is too small, the sludge accumulates on the foam metal 38. The refrigerant may not flow. Therefore, as an actual design, the porosity of the porous permeable material of the metal foam 38 is such that the sludge does not accumulate and the gas-liquid two-phase flow is mixed very well so that the cross-sectional area and thickness of the metal foam 38 are very good. Then, a means for adjusting the porosity and reducing the predetermined reduced pressure amount that cannot be secured by the flow resistance of the foam metal 38 by the orifice 39 is taken. Further, by providing an interval between the orifice 39 and the foam metal 38, the gas-liquid two-phase flow is better mixed. The clearance between the orifice 39 and the foam metal 38a and the clearance between the orifice 39 and the foam metal 38b may be the same. However, as shown in FIG. It is done. 12 is much cheaper than the flow rate control valve using the porous permeable material used for the main valve body 34 as shown in FIG. 10, and the electromagnetic on-off valve 37 is a conventional two-way valve. Since it can be diverted, even if the expansion device 36 and the electromagnetic opening / closing valve 37 are used in combination, the second flow rate control valve 10 of FIG.
[0090]
In the refrigerant circuit shown in FIG. 11, in order to operate the reheat dehumidifying operation in both the cooling circuit and the heating circuit, the refrigerant flow direction is reversed between the expansion device 36 and the electromagnetic on-off valve 37. Therefore, if the electromagnetic on-off valve 37 is a valve having a structure in which the refrigerant can be sealed by both flows, this function can be achieved.
[0091]
Embodiment 3 FIG.
An air conditioner according to a third embodiment of the present invention will be described. FIG. 13 is a refrigerant circuit of the present invention, and the same parts as those in FIG. The structure of the indoor unit is, for example, FIG. Each operation mode described in the first embodiment can be performed in the same manner. At this time, a refrigerant circuit using check valves 83a, 83b, 83c, and 83d is formed around the first flow control valve 24 and the gas-liquid separation container 82 of the outdoor unit 17. Hereinafter, the operation of this refrigerant circuit will be described.
[0092]
In this embodiment, the refrigerant flow direction during the cooling operation is a solid arrow, and the refrigerant passing through the point B is decompressed by the first flow control valve 24 through the check valve 83a, and the gas-liquid separation container 82 And the liquid refrigerant reaches the point C through the check valve 83b. On the other hand, the refrigerant flow direction during the heating operation is a dotted arrow, and the refrigerant passing through the point C is decompressed by the first flow control valve 24 through the check valve 83c and separated by the gas-liquid separation container 82. Then, the liquid refrigerant passes through the check valve 83d and reaches point B. As described above, in the refrigerant circuit shown in FIG. 13, the gas-liquid separation refrigeration cycle can be automatically configured for both cooling and heating operation, and refrigerant pressure loss is reduced for both cooling and heating to achieve highly efficient operation. Can do.
[0093]
Embodiment 4 FIG.
An air conditioner according to a fourth embodiment of the present invention will be described. FIG. 14 is a refrigerant circuit of the present invention, and the same parts as those in FIG. The structure of the indoor unit 18 is, for example, FIG. Each operation mode described in the first embodiment can be performed in the same manner. At this time, an accumulator 84 is provided in the compressor suction of the outdoor unit 17, and a gas bypass circuit 80 is installed upstream of the accumulator 84. Hereinafter, the operation of this refrigerant circuit will be described.
[0094]
When operating with the third flow control valve 81 open (reheat dehumidification operation in the heating circuit, operation in the gas-liquid separation refrigeration cycle, heating defrost operation, etc.), the flow control cannot catch up with the actual flow, and the gas In some cases, the liquid refrigerant flows into the bypass circuit 80. At this time, since the accumulator 84 is provided and the gas bypass circuit 80 is connected to the upstream side of the accumulator 84, gas-liquid separation is performed by the accumulator 84 and the liquid refrigerant is stored. Therefore, the liquid refrigerant does not return to the compressor suction more than necessary, so that the liquid compression state can be avoided and the reliability of the compressor can be improved. Moreover, since an excess refrigerant | coolant is stored by the accumulator 84, a refrigerating cycle can be drive | operated with the optimal refrigerant | coolant amount, and efficiency can be improved.
[0095]
In addition, the structural example of the gas-liquid separation container 82 used for the air conditioner described in the first to fourth embodiments is shown in FIGS. 15A shows an example in which the two-phase refrigerant inflow pipe enters from above, FIG. 15B shows an example in which the two-phase refrigerant inflow pipe enters from the horizontal direction, and FIG. 15C shows the two-phase refrigerant inflow pipe from the horizontal direction. An example in which the gas-liquid separation efficiency is improved by causing a swirling flow in the container and FIG. 15D shows an example in which the gas-liquid separation is performed also in the cooling circuit and the heating circuit. FIG. 16 (a) shows an example in which the two-phase refrigerant inflow pipe is extended to an intermediate level in the gas-liquid separation container, a hole is made in the horizontal direction of the pipe, and the refrigerant flow collides with the inner wall of the container. (B) is an example in which the two-phase refrigerant inflow pipe is extended to about the middle in the gas-liquid separation container, the pipe is bent in the lateral direction, the refrigerant flow collides with the inner wall of the container, and a swirling flow is generated. In order to bend the tube, the container is manufactured in two parts. In any of the examples of FIGS. 15 and 16, the flow rate of the flowing refrigerant and the volume of the container may be designed so as to obtain a predetermined gas-liquid separation efficiency. The gas-liquid separation container stores excess refrigerant in each operation mode such as cooling operation, heating operation, reheat dehumidification operation in the cooling circuit, reheat dehumidification operation in the heating circuit, heating defrost operation, etc. Therefore, it is possible to prevent the efficiency from being reduced due to excessive refrigerant and the failure of the compressor due to the liquid back operation when excess refrigerant flows into the compressor. Note that the volume of the gas-liquid separation container may be determined in advance as an internal volume that can store the difference between the maximum refrigerant amount and the minimum refrigerant amount by obtaining the optimum refrigerant amount in each operation mode by tests and calculations.
[0096]
The characteristics when R410A, R32, or R290 is used as the refrigerant used in the air conditioners described in the first to fourth embodiments will be described. R410A, R32, and R290 refrigerants have an ozone depletion coefficient of 0 compared to R22 refrigerant that has been used in conventional air conditioners, and in particular, R32 and R290 have a smaller global warming coefficient than R22 and R410A and are friendly to the global environment. It has the characteristic of a refrigerant. In addition, R410A, R32, and R290 have a characteristic that refrigerant pressure loss is smaller than that of R22. R410A and R290 have a refrigerant pressure loss of 70% compared to R22, and R32 has a refrigerant pressure loss of 50% compared to R22. Therefore, R410A, R32, and R290 have a characteristic that the temperature gradient between the evaporator inlet temperature and the outlet temperature becomes small, and the evaporator temperature becomes uniform. Therefore, the air that has exited the evaporator and has been cooled and dehumidified has no temperature unevenness, and it will mix very well with the heated air, and the dehumidified air without temperature drop will be blown out without temperature unevenness. It can be said that the refrigerant is more suitable for the purpose of this embodiment, which can create a very comfortable indoor environment.
[0097]
Moreover, although the example which installed the auxiliary heat exchanger 14 and comprised the refrigerant | coolant flow path by one system | strain was shown, since R410A, R32, and R290 have the characteristic that refrigerant | coolant pressure loss is small compared with R22, refrigerant | coolant flow velocity The effect of improving the heat transfer coefficient in the refrigerant pipe due to the improvement is great, and the heat exchange capability can be improved even in various operation modes. Usually, as shown in FIG. 2, the evaporator is distributed like the lower part of the front and the back, the auxiliary heat exchanger is provided, and the second flow control valve 10 is used. However, if a refrigerant having a small refrigerant pressure loss such as R410A, R32, or R290 is used, it is possible to provide a comfortable air-conditioning environment with little heat loss.
[0098]
In addition, as the refrigerant, HFC-based (R116, R125, R134a, R14, R143a, R152a, R227ea, R23, R236ea, R236fa, R245ca, R245fa, R32, R41, RC318, etc., and several mixed refrigerants R407A, R407B, R407C, R407D, R407E, R410B, R404A, R507A, R508A, R508B, etc.), HC system (butane, isobutane, ethane, propane, propylene, etc., some mixed refrigerants of these refrigerants), natural refrigerant (air, The ozone depletion coefficient is 0 no matter what kind of refrigerant is used, such as carbon dioxide, ammonia, or some mixed refrigerants of these refrigerants), or some mixed refrigerants such as these HFC, HC, and natural refrigerants, Reheat dehumidification operation described in the above embodiment The effect is exhibited.
[0099]
As described above, the heat transfer tube shape of the heat exchanger of the first indoor heat exchanger 25 serving as the reheater according to Embodiments 1 to 4 of the present invention and the heat exchanger of the second indoor heat exchanger 27 serving as the evaporator is a circular tube. For example, although the outer diameter is 10 mm or less, the effect is achieved even with an elliptical heat transfer tube or a flat heat transfer tube having a cross-sectional area equivalent to that of a circular tube. Further, for example, in the reheater, many heat raising fins 28 are provided to promote heat transfer with the air, and in the evaporator, the number of the raised heats is reduced to improve the exposure property. The cut-and-raised shape and fin pitch of the heat transfer fins 28 may be changed between the heat exchanger of the first indoor heat exchanger 25 serving as a heater and the second indoor heat exchanger 27 serving as an evaporator. Further, the cut-and-raised shape and fin pitch of the heat transfer fins 28 may be changed in each part of the multistage bending heat exchanger. Further, the shape and fin pitch of the heat transfer fins 28 may be changed between the first row heat exchanger and the second row heat exchanger. In addition, the number of rows may be changed in each part of the multistage bending heat exchanger. For example, the back heat exchanger 3 may be configured as a single row heat exchanger to reduce costs.
[0100]
In the air conditioners shown in the first to fourth embodiments, the heat exchanger has shown an example of a circular tube plate fin tube type, an elliptic tube plate fin tube type, a flat tube plate fin tube type, An elliptical tube / flat tube corrugated fin tube type may be used. Also, in the manufacture of these heat exchangers, especially when heat transfer tubes and fins are joined by brazing in the furnace, brazing is completed in one time, so the probability of refrigerant leakage due to brazing failure is reduced and there is combustibility. Safety when using R32 or R290 refrigerant can be further ensured. In addition, the contact heat resistance between the heat transfer tube and the fin can be drastically reduced, improving the heat exchanger performance. In addition, if the heat transfer tube and the fin are made of the same material such as copper or aluminum, the recyclability at the time of dismantling An excellent heat exchanger can be provided.
[0101]
Further, in Examples 1 to 4, the example in which R410A and R32 are used as the refrigerant has been shown, but the operating pressure of R410A and R32 is higher than that of the conventional refrigerant R22 (the heights of points D and E shown in FIG. 3). Therefore, the flow resistance at the second flow rate control valve 10 needs to be larger than that of the conventional refrigerant R22, and the amount of pressure reduction at the second flow rate control valve 10 needs to be larger than that of the conventional refrigerant R22. For this reason, for example, in the conventional second flow control valve 10 shown in FIG. 18, it is necessary to further reduce the orifice of the gap between the main valve seat 33 and the main valve body 34 to increase the flow resistance. When R410A is used When a gas-liquid two-phase flow inevitably passes through the conventional refrigerant R22, a very loud refrigerant flow noise is generated. Therefore, by applying the second flow rate control valve 10 using the porous permeable material shown in the present embodiment to the R410A refrigerant air conditioner, the effect of greatly reducing the refrigerant flow noise can be further exhibited. .
[0102]
In the air conditioners described in the first to fourth embodiments, the refrigerating machine oil may be a refrigerating machine oil that is incompatible or hardly soluble in the above-described refrigerants such as HCFC, HFC, HC refrigerant, natural refrigerant, or the like. Even if it is compatible refrigerating machine oil, the effect can be achieved for any refrigerating machine oil such as alkylbenzene, mineral oil, ester oil, ether oil, and fluorine oil.
[0103]
In the air conditioners described in the first to fourth embodiments, an example of an air conditioner having one outdoor unit 17 and one indoor unit 18 is shown. However, one outdoor unit 17 and one indoor unit 18 are shown. The effect is also achieved in an air conditioner having a plurality of units.
[0104]
In the air conditioners shown in the first to fourth embodiments, the compressor can be of any type, for example, a reciprocating compressor (single cylinder, plural cylinders), a rotary compressor (single cylinder, plural cylinders), a scroll. A compressor, a linear compressor, or the like may be used. Further, when the electric motor for rotating the compression portion is built in the compressor shell, the pressure structure in the shell may be high or low pressure. In the high-pressure shell method, the refrigerant exiting the compression cylinder cools the motor and is heated and discharged from the compressor, so the discharge temperature increases. On the other hand, in the low-pressure shell method, the refrigerant flowing into the shell is sucked into the compression cylinder after being heated by cooling the motor, so that the suction temperature becomes high. However, since the refrigerant flowing out from the compression cylinder is directly discharged out of the compressor, the discharge temperature is lowered. Depending on the refrigerant used, the discharge temperature is increased or decreased. In particular, the R32 refrigerant has a higher discharge temperature than the R410A refrigerant, and the R290 refrigerant has a lower discharge temperature than the R410A refrigerant. Choose between high pressure and low pressure. In general, the high-pressure shell has a larger amount of refrigerant and penetration into the compressor refrigeration oil than the low-pressure shell. Therefore, it is better to select the low-pressure shell method when it is desired to reduce the refrigerant charging amount. However, the refrigerant amount can be reduced even in the high-pressure shell by using refrigeration oil in which the refrigerant does not dissolve easily.
[0105]
In the air conditioner shown in Embodiments 1 to 4 of the present invention, the first flow control valve 24, the second flow control valve 10, or the like when the flammable R290 or R32 or the like is used as the refrigerant, or The effect when the third flow control valve 81 or all of the flow control valves are provided with a fully closed function will be described. At this time, by having a means for detecting refrigerant leakage, when refrigerant leakage is detected during operation or stop of the air conditioner, the refrigerant is sealed in the refrigerant circuit by fully closing these flow control valves, Leakage of refrigerant into the room can be prevented, and safety in an air conditioner using a flammable refrigerant can be ensured.
[0106]
The present invention includes a compressor, an indoor heat exchanger, a first flow control valve, an outdoor heat exchanger, and a four-way valve. The indoor heat exchanger is divided and a second flow control valve is provided therebetween, and the first flow control is performed. A gas-liquid separation container is provided between the valve and the indoor heat exchanger, a gas bypass circuit from the gas-liquid separation container is connected to the compressor suction, and a third flow control valve is provided on the gas bypass circuit. The four-way valve is switched to the cooling circuit, the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow control valve, the gas-liquid separation container, the upstream indoor heat exchanger, the second flow control valve, the downstream indoor The heat exchanger, four-way valve, flow into the compressor suction, the third flow control valve is fully closed, the first flow control valve is fully open, and the second flow control valve has an operation mode for performing flow control, And the four-way valve is switched to the heating circuit, the refrigerant is discharged from the compressor, the four-way valve, upstream Indoor heat exchanger, second flow control valve, downstream indoor heat exchanger, gas-liquid separation container, third flow control valve, flow into compressor suction, third flow control valve fully open, second flow control valve Since it has an operation mode in which the flow rate is controlled at, reheat dehumidification operation can be performed regardless of the outside air temperature condition, and a comfortable indoor environment can be obtained throughout the year. In addition, since a porous permeable material communicating with the refrigerant flow direction is used as the flow resistor of the first flow control valve, the second flow control valve or the third flow control valve, the refrigerant flow sound passing through the flow control valve is greatly increased. In addition, there is no need to take measures such as wrapping a sound insulation material or vibration damping material around the flow control valve, and the cost is reduced. Recyclability is also improved.
[0107]
Further, the auxiliary heat that is thermally shut off on the upstream side of the refrigerant flow of the reheater in the reheat dehumidification operation mode in which the refrigerant flow upstream side of the second flow rate control valve is operated as a reheater and the refrigerant flow downstream side is operated as an evaporator. Since the exchanger is provided, the capacity of the reheat heat exchanger is increased, the amount of reheat heat exchange is increased, and the capability control range for reheat dehumidification can be increased while preventing a decrease in room temperature. In addition, the space in the indoor unit can be used effectively, and the indoor unit can be made compact. Moreover, the indoor heat exchanger capability at the time of normal heating operation can be improved. Moreover, since the auxiliary heat exchanger is installed on the air flow upstream side of the reheater, the refrigerant flows facing the air having a low temperature, and the heat exchange performance can be further improved. Moreover, since the ventilation resistance of the auxiliary heat exchanger is made smaller than that of other heat exchangers, the heat exchange performance can be improved while suppressing an increase in pressure loss on the ventilation side.
[0108]
A device for inputting a required air conditioning load for latent heat and sensible heat in the room in a reheat dehumidifying operation mode in which the upstream side of the refrigerant flow of the second flow rate control valve is operated as a reheater and the downstream side of the refrigerant flow as an evaporator; A means for detecting the current latent heat and sensible heat air conditioning load in the room, a means for adjusting the amount of air blown to the indoor heat exchanger, a means for adjusting the amount of air blown to the outdoor heat exchanger, the rotational speed of the compressor , A means for adjusting the opening of the first flow control valve, a means for adjusting the opening of the second flow control valve, and detection information of the current indoor latent heat and sensible heat air conditioning load In addition, the indoor heat according to the required air conditioning load based on the current values of the indoor heat exchanger air flow, the outdoor heat exchanger air flow, the compressor rotation speed, the first flow control valve opening, and the second flow control valve opening Air flow to the exchanger, air flow to the outdoor heat exchanger, compressor speed, 1st A means for calculating the amount of change in the amount control valve opening and the second flow rate control valve opening in the arithmetic unit is provided. Since the latent heat and the sensible heat exchange amount are controlled, the latent heat and the sensible heat exchange amount can be controlled according to the latent heat and the sensible heat load in the room. According to the invention of claim 3, four check valves are connected to the first flow control valve and the refrigerant circuit around the gas-liquid separation container, and both the cooling circuit and the heating circuit are connected to the first flow control valve. Since the refrigerant flow is such that the decompressed refrigerant is gas-liquid separated in the gas-liquid separation container, high-efficiency operation can be realized even during cooling and heating.
[0109]
【The invention's effect】
An air conditioner according to the present invention includes a compressor, an indoor heat exchanger, a first flow control valve, an outdoor heat exchanger, a four-way valve, and an air conditioner provided with a refrigerant circuit that circulates the refrigerant. A second flow rate control valve provided between the divided exchangers, a gas-liquid separation container provided between the first flow rate control valve and the indoor heat exchanger or the outdoor heat exchanger, A gas bypass circuit having a third flow rate control valve on a bypass circuit connected to the compressor suction from the liquid separation container, wherein the refrigerant is discharged from the compressor, the four-way valve, and the upstream chamber using the four-way valve as a heating circuit Heat exchanger, second flow rate control valve, downstream indoor heat exchanger, gas-liquid separation container, third flow rate control valve, flow into compressor suction, the third flow rate control valve is fully open, and the first flow rate control The valve is fully closed and the second flow control valve is used to control the flow rate. Since having a reheat dehumidification operation mode in the circuit, efficiently, it is possible to easily achieve dehumidifying operation.
[0112]
An air conditioner according to the present invention uses the four-way valve as a cooling circuit, and the refrigerant is discharged from a compressor, a four-way valve, an outdoor heat exchanger, a first flow control valve, a gas-liquid separation container, an upstream indoor heat exchanger, The second flow control valve, the downstream indoor heat exchanger, the four-way valve, and the compressor suction flow, and the gas refrigerant separated in the gas-liquid separation container passes through the third flow control valve and sucks the compressor. A cooling operation mode in which the second flow rate control valve is fully open, the flow rate control of the main refrigerant circuit is controlled by the first flow rate control valve, and the flow rate control of the gas bypass circuit is controlled by the third flow rate control valve. Therefore, the cooling capacity can be increased and the cooling operation can be performed at a higher rate.
[0113]
An air conditioner according to the present invention uses a four-way valve as a heating circuit, refrigerant is discharged from a compressor, a four-way valve, an upstream indoor heat exchanger, a second flow control valve, a downstream indoor heat exchanger, a gas-liquid separation container, The first flow control valve, the outdoor heat exchanger, the four-way valve, and the compressor flow, the third flow control valve is fully closed, the second flow control valve is fully opened, and the first flow control valve is used for flow. Since it has a heating operation mode for performing control, it is possible to realize an increase in heating capacity and a highly efficient heating operation.
[0114]
The air conditioner according to the present invention switches the four-way valve to a cooling circuit during the heating and defrosting operation, and the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow control valve, and the gas-liquid separation container. The third flow control valve flows into the compressor suction, and has an operation mode in which the first flow control valve and the third flow control valve are fully opened, so that a comfortable indoor environment can be obtained by a short defrosting operation. Can be obtained and energy-saving operation can be realized.
[0115]
An air conditioner according to the present invention includes a compressor, an indoor heat exchanger, a first flow control valve, an outdoor heat exchanger, a four-way valve, and an air conditioner provided with a refrigerant circuit that circulates the refrigerant. A second flow rate control valve provided between the divided exchangers, a gas-liquid separation container provided between the first flow rate control valve and the indoor heat exchanger or the outdoor heat exchanger, Gas bypass circuit having a third flow rate control valve on the bypass circuit connected to the compressor suction from the liquid separation container, and temperature and humidity provided at the suction port for sucking indoor air of the indoor unit provided with the indoor heat exchanger A latent heat sensible heat load detection device that requires addition of air conditioning in the room by a deviation between the temperature and humidity of the intake air detected by the detection means and a preset temperature and humidity, and at least reheat dehumidification operation and heating in the cooling circuit Re-in circuit It has an operation mode of dehumidification operation, and operates by switching the operation mode depending on whether the load detected by the latent heat sensible heat load detection device is within the latent heat sensible heat capacity control range set in advance in each operation mode. Therefore, flexible and highly efficient operation can be realized according to the capacity change of the indoor load.
[0116]
Moreover, according to the invention which concerns on Claim 8, in an air conditioner provided with the compressor, the indoor heat exchanger, the 1st flow control valve, the outdoor heat exchanger, and the four-way valve, the indoor heat exchanger is divided | segmented between them. A second flow control valve is provided, and a gas-liquid separation container is provided between the first flow control valve and the indoor heat exchanger, and a gas bypass circuit from the gas-liquid separation container is connected to the compressor suction. A third flow rate control valve is provided on the gas bypass circuit, and the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow rate control valve, the gas-liquid separation container, and the upstream indoor heat. It flows to the exchanger, the second flow control valve, the downstream indoor heat exchanger, the four-way valve, and the compressor suction, the third flow control valve is fully closed, and the flow is controlled by the first flow control valve or the second flow control valve. The first operation mode for control and the four-way valve as a heating circuit, the refrigerant is discharged from the compressor , Four-way valve, upstream indoor heat exchanger, second flow control valve, downstream indoor heat exchanger, gas-liquid separation container, third flow control valve, flow into compressor intake, third flow control valve fully open And a second operation mode in which the flow rate is controlled by the second flow rate control valve. Since the first operation mode and the second operation mode can be switched alternately, high efficiency can be achieved according to changes in the capacity of the indoor load. Can be realized.
[0117]
According to the ninth aspect of the invention, the four-way valve is switched to the cooling circuit, and the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow control valve, the gas-liquid separation container, the upstream side indoor heat. The refrigerant flows into the exchanger, the second flow control valve, the downstream indoor heat exchanger, the four-way valve, and the compressor suction, and the gas refrigerant separated in the gas-liquid separation container passes through the third flow control valve and sucks the compressor. The third flow rate control valve is fully open, the first flow rate control valve controls the flow rate of the main refrigerant circuit, and the third flow rate control valve controls the flow rate of the gas bypass circuit. And since it can switch alternately with the 1st operation mode, the highly efficient operation which can respond to change of an operation mode and the capability change of indoor load smoothly can be realized.
[0118]
According to the invention of claim 10, the valve opening control of the first flow control valve is a value corresponding to the degree of refrigerant heat at the outlet of the indoor heat exchanger, and the valve opening control of the third flow control valve is compressed. Since there is an operation mode in which the flow rate control is performed with the target values corresponding to the compressor suction refrigerant superheat degree, the compressor discharge refrigerant superheat degree, and the compressor discharge refrigerant temperature, highly efficient and reliable operation can be realized.
[0119]
According to the invention of claim 11, since the valve opening degree control of the third flow rate control valve has an operation mode in which the flow rate control is performed according to the compressor rotational speed, the highly efficient operation according to the capacity change. Can be realized.
[0120]
According to the twelfth aspect of the invention, in the heating and defrosting operation, the four-way valve is switched to the cooling circuit, and the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow control valve, the gas-liquid separation. Because it has an operation mode in which the container, the third flow control valve, the compressor flow, and the first flow control valve and the third flow control valve are fully opened, the defrosting time can be shortened and the comfortable indoor environment Can be obtained quickly.
[0121]
According to the invention of claim 13, the refrigerant flow upstream of the reheater in the reheat dehumidifying operation mode in which the second flow control valve is operated with the refrigerant flow upstream side as the reheater and the refrigerant flow downstream side as the evaporator. The auxiliary heat exchanger that is thermally shut off from the reheater is provided on the side, so that the amount of reheat heat exchange during reheat dehumidification operation can be increased, and a wide range of latent heat sensible heat capacity control operation can be performed. Can be realized.
[0122]
According to the invention of claim 14, since the refrigerant flow path of the auxiliary heat exchanger is made into one system, the in-pipe refrigerant heat transfer performance during operation when the gas-liquid separator is used can be improved. The heating capacity of the exchanger is further improved and highly efficient operation is possible.
[0123]
Further, according to the invention according to claim 15, since the porous permeating material communicating in the refrigerant flow direction is used as the flow resistor of the first flow control valve, the second flow control valve or the third flow control valve, Refrigerant flow noise passing through the flow control valve can be greatly reduced, and a special material for noise prevention is not required, so that the recyclability of the air conditioner is improved.
[0124]
According to the sixteenth aspect of the present invention, instead of the second flow rate control valve, as a throttle device, the orifice and the refrigerant flow in the upstream direction, the downstream direction, or the upstream / downstream direction are sandwiched between the orifices and the refrigerant flow direction. A porous permeable material that communicates with the refrigerant, or a porous permeable material that is independently arranged to act as a flow resistor, a refrigerant flow path that bypasses the expansion device, and a means for opening and closing the bypass flow path, Since the refrigerant flow noise passing through the second flow rate control valve is greatly reduced, the structure of the second flow rate control valve is simplified and the cost can be reduced.
[0125]
According to the invention of claim 17, since the on-off valve that can be sealed against bidirectional flow is used as the means for opening and closing the bypass flow path, the reheat dehumidification operation is realized even in the cooling circuit and the heating circuit. It is possible to obtain a comfortable indoor environment without depending on outside temperature conditions.
[0126]
According to the eighteenth aspect of the present invention, in the circuit in which the first flow control valve and the gas-liquid separation container are connected, the refrigerant depressurized by the first flow control valve in both the cooling direction and the heating direction is supplied to the gas-liquid separation container. High-efficiency operation can be realized both during cooling and heating by connecting a switching circuit in which the flow from the first flow control valve to the gas-liquid separation container is always constant so as to obtain a refrigerant flow for gas-liquid separation.
[0127]
According to the nineteenth aspect of the present invention, since the liquid reservoir is provided on the compressor suction side, it is possible to absorb excess refrigerant in the refrigerant circuit and realize high-efficiency and high-reliability operation.
[0128]
According to the twentieth aspect of the present invention, since the third flow rate control valve is composed of a capillary tube and an electromagnetic on-off valve, the cost can be reduced with a simple configuration.
[0129]
Moreover, according to the invention which concerns on Claim 21, since R410A or R32 or R290 was used as a refrigerant | coolant, it can be useful for ozone layer destruction prevention and global warming.
[0130]
According to the invention of claim 22, R290 or R32 is used as the refrigerant, and the first flow control valve, the second flow control valve, or both flow control valves are provided with a fully-closed function, and refrigerant leakage is prevented. It has a means to detect, and when a refrigerant leak is detected, a means to fully close these flow control valves is provided, so that it is possible to prevent the refrigerant from leaking into the room with respect to the combustible refrigerant and to ensure the safety of the equipment. it can.
[0131]
According to the invention of claim 23, the air condition setting means for setting the target value of the indoor air condition, the air condition detection means for detecting the indoor air condition, and the air flow rate to the indoor heat exchanger are adjusted. The indoor air flow rate adjusting means, the outdoor air flow rate adjusting means for adjusting the air flow rate to the outdoor heat exchanger, the compressor rotational speed adjusting means for adjusting the rotational speed of the compressor, and the opening of the first flow control valve An air conditioner comprising: a first flow control valve opening adjusting means for adjusting the second flow control valve opening adjusting means for adjusting an opening of the second flow control valve; Operating the air conditioner in a reheat dehumidifying operation mode in which the indoor heat exchanger on the upstream side of the refrigerant flow is operated as a reheater and the indoor heat exchanger on the downstream side of the refrigerant flow is used as an evaporator; and the air in operation From the target value and the detected value of the indoor air condition of the In order to reduce the difference between the target value and the detected value of the sensible air conditioning load and the difference between the latent heat in the room and the air load of the sensible heat, the air flow to the indoor heat exchanger and the flow to the outdoor heat exchanger A step of changing at least one of the air flow rate, the rotational speed of the compressor, the opening degree of the first flow rate control valve, and the opening degree of the second flow rate control valve. This makes it possible to operate an air conditioner that is easy to use and uses less energy.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration of an indoor unit according to the first embodiment of the present invention.
FIG. 3 is a characteristic diagram showing an operation state during a reheat dehumidification operation in the cooling circuit according to the first embodiment of the present invention.
FIG. 4 is a characteristic diagram illustrating an operation state during a reheat dehumidification operation in the heating circuit according to the first embodiment of the present invention.
FIG. 5 is a characteristic diagram showing an operation state in the gas-liquid separation circuit according to the first embodiment of the present invention.
FIG. 6 is a refrigerant circuit diagram, a sensor, and an actuator configuration in the first embodiment of the present invention.
FIG. 7 is a diagram illustrating a capability control range and an operation switching operation map in the first embodiment of the present invention.
FIG. 8 is a diagram illustrating another configuration of the indoor unit according to the first embodiment of the present invention.
FIG. 9 is a diagram illustrating still another configuration of the indoor unit according to the first embodiment of the present invention.
FIG. 10 is a diagram showing a configuration of a second flow control valve in the first embodiment of the present invention.
FIG. 11 is a refrigerant circuit diagram according to a second embodiment of the present invention.
FIG. 12 is a diagram showing a configuration of a second flow rate control valve in the second embodiment of the present invention.
FIG. 13 is a refrigerant circuit diagram according to a third embodiment of the present invention.
FIG. 14 is a refrigerant circuit diagram according to a fourth embodiment of the present invention.
FIG. 15 is a diagram showing a configuration of a gas-liquid separation container in the first to fourth embodiments of the present invention.
FIG. 16 is a diagram showing a configuration of a gas-liquid separation container in the first to fourth embodiments of the present invention.
FIG. 17 is a diagram illustrating a configuration of an indoor unit in a conventional invention.
FIG. 18 is a refrigerant circuit diagram in a conventional invention.
FIG. 19 is a diagram showing a configuration of a second flow control valve in a conventional invention.
[Explanation of symbols]
5: Indoor blower, 10: Second flow control valve, 14: Auxiliary heat exchanger, 17: Outdoor unit, 18: Indoor unit, 21: Compressor, 23: Outdoor heat exchanger, 24: First flow control valve, 25: 1st indoor heat exchanger, 27: 2nd indoor heat exchanger, 38: Foam metal, 80: Gas bypass circuit, 81: 3rd flow control valve, 82: Gas-liquid separation container.

Claims

Compressor, an indoor heat exchanger, the first flow control valve, an outdoor heat exchanger, the air conditioner having a refrigerant circuit for circulating a refrigerant having a four-way valve, disposed therebetween dividing the indoor heat exchanger connected to the second flow control valve, and a gas-liquid separation vessel which is provided between the first flow control valve and the indoor heat exchanger or the outdoor heat exchanger, the compressor suction from the gas-liquid separation vessel includes a gas bypass circuit with a third flow control valve has been bypassed circuit on the said refrigerant compressor discharge the four-way valve as the heating circuit, the four-way valve, the upstream side indoor heat exchanger, the second flow control Valve, downstream indoor heat exchanger, gas-liquid separation container, third flow control valve, flow into the compressor suction, the third flow control valve is fully open, the first flow control valve is fully closed, the reheat dehumidifying operation mode in the heating circuit for controlling the flow rate at second flow control valve An air conditioner characterized by.

In the air conditioning apparatus according to claim 1, the four-way valve as the cooling circuit, the refrigerant compressor discharge, the four-way valve, an outdoor heat exchanger, the first flow control valve, the gas-liquid separation vessel, upstream indoor heat exchanger, second flow control valve, downstream indoor heat exchanger, the four-way valve, flows into the compressor suction Rutotomoni, the compressor gas refrigerant separated is passed through the third flow control valve at the gas-liquid separation vessel Cooling operation in which the second flow control valve is fully opened, the flow control of the main refrigerant circuit is performed by the first flow control valve, and the flow control of the gas bypass circuit is performed by the third flow control valve. An air conditioner having a mode .

In the air conditioning apparatus according to claim 1, a four-way valve as the heating circuit, the refrigerant compressor discharge, the four-way valve, the upstream side indoor heat exchanger, the second flow control valve, downstream indoor heat exchanger, the gas-liquid separator container The first flow control valve, the outdoor heat exchanger, the four-way valve, and the compressor suction, the third flow control valve is fully closed, the second flow control valve is fully opened, and the first flow control valve An air conditioner having a heating operation mode for performing flow rate control .

The air conditioner according to claim 1 , wherein the four-way valve is switched to a cooling circuit during heating and defrosting operation, and the refrigerant is discharged from a compressor, a four-way valve, an outdoor heat exchanger, a first flow control valve, and a gas-liquid separation container. The air conditioner has an operation mode in which the third flow control valve flows into the compressor suction and the first flow control valve and the third flow control valve are fully opened .

In an air conditioner having a compressor, an indoor heat exchanger, a first flow control valve, an outdoor heat exchanger, a four-way valve and a refrigerant circuit that circulates the refrigerant, the indoor heat exchanger is divided and provided therebetween. A second flow rate control valve, a gas-liquid separation container provided between the first flow rate control valve and the indoor heat exchanger or the outdoor heat exchanger, and the gas-liquid separation container connected to the compressor suction A gas bypass circuit having a third flow rate control valve on the bypass circuit, and an intake air detected by a temperature / humidity detection means provided in an intake port for sucking indoor air of the indoor unit provided with the indoor heat exchanger. A latent heat sensible heat load detection device that requires addition of air conditioning in the room based on a deviation between temperature and humidity and a preset temperature and humidity, and at least a reheat dehumidifying operation in the cooling circuit and a reheat dehumidifying operation in the heating circuit Mode Serial load detected by the latent heat sensible heat load sensing device, according to whether or not the latent heat sensible heat capacity control range set in advance in each operation mode, the air conditioner characterized in that it operates by switching the operation mode.

In the air conditioner definitive to claim 5, as the cooling circuit of the four-way valve, the refrigerant is compressor discharge, the four-way valve, an outdoor heat exchanger, the first flow control valve, the gas-liquid separation vessel, upstream indoor heat exchanger , The second flow control valve, the downstream indoor heat exchanger, the four-way valve, and the compressor suction, the third flow control valve is fully closed, and at least one of the first flow control valve and the second flow control valve An air conditioner having a reheat dehumidifying operation mode in a cooling circuit that performs flow rate control in any one of the above .

6. The air conditioner according to claim 5 , wherein the refrigerant is a compressor discharge, a four-way valve, an upstream indoor heat exchanger, a second flow control valve, a downstream indoor heat exchanger, and a gas-liquid separation container using the four-way valve as a heating circuit. A heating circuit that controls the flow rate with the second flow rate control valve, the third flow rate control valve flows into the compressor suction, the third flow rate control valve is fully open, the first flow rate control valve is fully closed An air conditioner having a reheat dehumidifying operation mode .

In an air conditioner including a compressor, an indoor heat exchanger, a first flow control valve, an outdoor heat exchanger, and a four-way valve, the indoor heat exchanger is divided and a second flow control valve is provided therebetween, and the first A gas-liquid separation container is provided between the flow control valve and the indoor heat exchanger, a gas bypass circuit from the gas-liquid separation container is connected to the compressor suction, and a third flow control valve is provided on the gas bypass circuit. And a four-way valve as a cooling circuit, the refrigerant is discharged from the compressor, the four-way valve, the outdoor heat exchanger, the first flow control valve, the gas-liquid separation container, the upstream indoor heat exchanger, the second flow control valve, the downstream side The first operation mode in which the indoor heat exchanger, the four-way valve, the compressor flow, the third flow control valve is fully closed, and the flow control is performed by the first flow control valve or the second flow control valve, With the valve as the heating circuit, the refrigerant is discharged from the compressor, the four-way valve, the upstream indoor heat exchanger The second flow control valve, the downstream indoor heat exchanger, the gas-liquid separation container, the third flow control valve, the compressor flow into the compressor, the third flow control valve is fully open, and the second flow control valve controls the flow. The air conditioner has a second operation mode to be performed, and the first operation mode and the second operation mode can be switched alternately.

In the air conditioning apparatus according to claim 8, it switches the four-way valve to the cooling circuit, the refrigerant compressor discharge, the four-way valve, an outdoor heat exchanger, the first flow control valve, the gas-liquid separation vessel, upstream indoor heat exchanger the second flow control valve, downstream indoor heat exchanger, a four-way valve, with flow to the compressor suction, the compressor gas refrigerant separated by the gas-liquid separation vessel through said third flow control valve flows to the suction, the second flow control valve is fully open, a third of the flow rate control of the main refrigerant circuit in the first flow control valve, the flow rate control of the gas bypass circuit in said third flow control valve It has the operating mode of the air conditioner, characterized in that a switchable to the first operation mode and alternating.

The valve opening control of the first flow control valve is a value corresponding to the indoor heat exchanger outlet refrigerant superheat, the valve opening control of the third flow control valve, the compressor suction refrigerant superheating degree, the compressor discharge refrigerant The air conditioner according to at least one of claims 1 to 9, wherein the air conditioner has an operation mode in which flow rate control is performed with a target corresponding to a degree of superheat and a compressor discharge refrigerant temperature.

10. The air conditioner according to claim 1, wherein the valve opening degree control of the third flow rate control valve has an operation mode in which flow rate control is performed in accordance with a compressor rotational speed.

Switching the four-way valve to the cooling circuit, the refrigerant compressor discharge, the four-way valve, an outdoor heat exchanger, the first flow control valve, the gas-liquid separation vessel, the third flow control valve, flows into the compressor suction, the first 10. The air conditioner according to claim 8, wherein the air conditioner has a fourth operation mode in which one flow control valve and the third flow control valve are fully opened.

Reheater refrigerant flow upstream side of the second flow control valve, the refrigerant flow upstream side of the reheater reheat dehumidifying operation mode for operating the refrigerant flow downstream side as an evaporator, the reheater in thermal 13. An air conditioner according to claim 1, further comprising an auxiliary heat exchanger interrupted by the air conditioner.

14. The air conditioner according to claim 13, wherein the auxiliary heat exchanger has a single refrigerant flow path.

As flow resistance of the first flow rate control valve or the second flow rate control valve or the third flow control valve, according to claim 1 to 12, characterized by using a porous permeable member communicating with the refrigerant flow direction An air conditioner according to at least one of the above.

As a throttle device in place of the second flow control valve, an orifice and the refrigerant flow upstream or downstream direction, or the vertical flow direction, arranged a porous permeable member communicating with the refrigerant flow direction in the structure sandwiching the orifice, or 16. A porous permeation material is provided alone to act as a flow resistor, and further includes a refrigerant flow path that bypasses the expansion device and means for opening and closing the refrigerant flow path. The air conditioner described.

The air conditioner according to claim 16, wherein an opening / closing valve capable of sealing against bidirectional flow is used as means for opening and closing the refrigerant flow path.

A circuit connected to the gas-liquid separation vessel and said first flow control valve, the cooling direction, both heating direction, to the gas-liquid separating the refrigerant decompressed by the first flow control valve in the gas-liquid separation vessel at least an air conditioner according of claims 1 to 17, characterized in that the flow from the first flow control valve so as to be the refrigerant flowing into the gas-liquid separation vessel always connect a variable composed switching circuit .

The air conditioner according to at least one of claims 1 to 18, wherein a liquid reservoir is provided on the suction side of the compressor.

The air conditioner according to at least one of claims 1 to 19, wherein the third flow rate control valve comprises a capillary tube and an electromagnetic on-off valve.

The air conditioner according to at least one of claims 1 to 20, wherein R410A, R32, or R290 is used as the refrigerant.

With R290 or R32 as the refrigerant, provided with a fully closed function to at least one of the flow control valve of the first flow control valve and the second flow control valve and the third flow control valve, detecting refrigerant leakage The air conditioner according to at least one of claims 1 to 21, further comprising means for fully closing the flow rate control valve when refrigerant leakage is detected.

A compressor, an indoor heat exchanger, a first flow control valve, an outdoor heat exchanger, a refrigerant circuit having a four-way valve for circulating refrigerant, and a second flow control valve provided between the indoor heat exchanger divided A gas-liquid separation container provided between the first flow control valve and the indoor heat exchanger or the outdoor heat exchanger, and a bypass circuit connected to the compressor suction from the gas-liquid separation container a gas bypass circuit with a third flow control valve, and the air condition setting means for setting a target value of the room air condition, an air condition detecting means for detecting an air state of the room, air blowing amount to the indoor heat exchanger and indoor blowing amount adjusting means for adjusting the, outdoor air volume adjusting means for adjusting the air volume to the outdoor heat exchanger, a compressor rotational speed adjusting means for adjusting the rotational speed of the compressor, the first flow rate First flow control valve opening adjustment hand to adjust the opening of the control valve When a second flow rate control valve opening adjusting means for adjusting an opening degree of the second flow control valve, in the air conditioner having a indoor heat exchanger of the refrigerant flow upstream side of the second flow control valve reheater, a step of operating the air conditioner of the indoor heat exchanger of the refrigerant flow downstream side at the reheat dehumidification operation mode is operated as an evaporator, the target value of the room air state of the air conditioner in operation Determining the difference between the target value and detection value of the indoor latent heat and sensible heat air-conditioning load from the detected value and the indoor heat exchanger in a direction to reduce the difference between the indoor latent heat and sensible heat air load. blowing amount to, air blowing amount to the outdoor heat exchanger, the rotation speed of the compressor, the opening degree of the first flow control valve, and change at least one of the opening degree of the second flow control valve An air condition characterized by comprising: The method of operation.