JP4288934B2

JP4288934B2 - Air conditioner

Info

Publication number: JP4288934B2
Application number: JP2002331582A
Authority: JP
Inventors: 貴弘山口
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2002-11-15
Filing date: 2002-11-15
Publication date: 2009-07-01
Anticipated expiration: 2022-11-15
Also published as: JP2004163052A

Description

【０００１】
【発明の属する技術分野】
本発明は、空気調和装置に関し、特に、除湿運転が可能な空気調和装置に係るものである。
【０００２】
【従来の技術】
従来より、空気調和装置における除湿運転の方式として、室内熱交換器で除湿・冷却した空気を加熱（再熱）して、吹き出し空気の温度低下を抑える方式が知られている。しかし、この方式の空気調和装置では、室内熱交換器における顕熱処理量が比較的大きいため、省エネ性に改善の余地がある。
【０００３】
そこで、除湿運転時の処理効率を高めるため、室内熱交換器を３つの熱交換器で構成した空気調和装置が提案されている（例えば、特許文献１参照）。この特許文献１の空気調和装置では、室内熱交換器は、空気通路の上流側から下流側へ順に配設された第１熱交換器、第２熱交換器、及び第３熱交換器から構成されている。
【０００４】
この空気調和装置では、除湿運転時には、冷媒回路において、圧縮機、凝縮器、中間圧膨張弁、上記第１熱交換器、上記第３熱交換器、膨張弁、上記第２熱交換器の順に冷媒を循環させて冷凍サイクルを行う。このとき、冷媒は、第１熱交換器において中間圧で蒸発し、その際に空気を冷却（予冷）した後に第３熱交換器へ流入して、室内へ還気される空気を加熱（再熱）する。また、第３熱交換器から第２熱交換器へ流入した冷媒は、第１熱交換器を通過してきた空気を冷却して蒸発した後、圧縮機へ吸入される。この冷媒回路によると、除湿運転時には、第１熱交換器で予冷した室内空気が第２熱交換器を通過するため顕熱処理量が小さくなり、潜熱処理効率のよい除湿運転が可能となる。
【０００５】
【特許文献１】
特開２００１−１４７０３２号公報
【０００６】
【発明が解決しようとする課題】
一方、上記空気調和装置で暖房運転を行うときは、冷媒回路において冷媒の循環方向を反転させることにより、冷媒は第２熱交換器、第３熱交換器、第１熱交換器を順に流れることになる。このとき、室内空気は、第１熱交換器、第２熱交換器、第３熱交換器を順に通過する。また、冷房運転の場合、膨張弁の制御は異なるが、冷媒や空気の流れそのものは除湿運転時と同じである。
【０００７】
しかし、暖房運転時や冷房運転時の運転効率を考えると、冷媒を３つの熱交換器に並列に流したり、直列の場合でも除湿運転時とは異なる順序で流したりすることが好ましい場合もある。つまり、上記特許文献１の冷媒回路では、冷房運転時や暖房運転時には空気流れに対する冷媒流れの関係を最適化することができず、空気調和装置としてのトータルの運転効率が低下することがあった。
【０００８】
本発明は、このような問題点に鑑みて創案されたものであり、その目的は、室内側に３つの熱交換器を備えた空気調和装置において、除湿運転時の運転効率が低下するのを防止するとともに、冷房運転時や暖房運転時にも運転効率が低下しないようにすることである。
【０００９】
【課題を解決するための手段】
本発明は、室内熱交換器(7) を構成する３つの熱交換器(11,12,13)における冷媒流れを冷房運転時や暖房運転時と除湿運転時とで切り換えられるように、これら熱交換器(11,12,13)の前後に切換手段(4)(8)を設けたものである。
【００１０】
具体的に、請求項１に記載の発明は、圧縮機(3) と室外熱交換器(5) と膨張機構(6) と室内熱交換器(7) とが順に接続された冷媒回路(2) を備え、室内熱交換器(7) が空気流れの上流側から下流側へ順に配設された第１熱交換器(11)、第２熱交換器(12)及び第３熱交換器(13)から構成された空気調和装置を前提としている。そして、この空気調和装置は、室内熱交換器(7) を構成する各熱交換器(11,12,13)における冷媒の流れを切り換える切換手段(4)(8)を備えている。
【００１１】
この請求項１の発明では、室内熱交換器(7) である第１熱交換器(11)、第２熱交換器(12)、及び第３熱交換器(13)において、上記切換手段(4)(8)により冷媒の流れる方向や順序を切り換えることが可能となる。このため、除湿運転時を始め、冷房運転時や暖房運転時にも効率のよい冷媒流れを選択することが可能となる。
【００１２】
また、請求項１から請求項３に記載の発明は、切換手段(4)(8)による具体的な冷媒流れの切り換えの仕方を特定したもので、請求項１に記載の発明は、切換手段(4)(8)が、室内熱交換器(7) を構成する各熱交換器(11,12,13)における冷媒の流れを直列と並列に切り換えるように構成されていることを特徴としている。
【００１３】
また、請求項２に記載の発明は、請求項１に記載の空気調和装置において、切換手段(4)(8)が、室内熱交換器(7) を構成する各熱交換器(11,12,13)における冷媒の流れを直列と並列に切り換えるとともに、直列及び並列の少なくとも一方で、可逆の冷媒流れが可能であることを特徴とするものである。
【００１４】
また、請求項３に記載の発明は、請求項２に記載の空気調和装置において、切換手段(4)(8)が、第１熱交換器(11)、第３熱交換器(13)、第２熱交換器(12)を冷媒が順に流れる直列流れと、可逆の並列流れとを可能にするように構成されていることを特徴とするものである。
【００１５】
これら請求項１から請求項３の発明では、第１熱交換器(11)、第２熱交換器(12)及び第３熱交換器(13)において冷媒が直列に流れる状態や並列に流れる状態を運転状態に応じて適宜選択することが可能となる。特に、請求項３の発明において、除湿運転時に冷媒が第１熱交換器(11)、第３熱交換器(13)、第２熱交換器(12)を順に（直列に）流れる状態と、冷房運転時や暖房運転時に冷媒が各熱交換器(11,12,13)を並列に流れる状態とを選択することにより、各運転時の効率低下を抑えられる。
【００１６】
また、請求項４に記載の発明は、請求項３に記載の空気調和装置において、冷媒回路の構成を特定したものである。すなわち、この発明では、図１に示すように、冷媒回路(2) における冷媒の循環方向が可逆に構成され、冷媒回路(2) の液側配管(PL)が、主液管(20)から分岐した第１液分岐管(21)及び第２液分岐管(22)と、該第２液分岐管(22)から分岐した第３液分岐管(23)とを備えるとともに、第１液分岐管(21)が第１熱交換器(11)の第１端部に、第２液分岐管(22)が第２熱交換器(12)の第１端部に、第３液分岐管(23)が第３熱交換器(13)の第１端部に接続されている。また、冷媒回路(2) のガス側配管(PG)が、主ガス管(30)から分岐した第２ガス分岐管(32)及び第３ガス分岐管(33)と、該第３ガス分岐管(33)から分岐した第１ガス分岐管(31)とを備えるとともに、第１ガス分岐管(31)が第１熱交換器(11)の第２端部に、第２ガス分岐管(32)が第２熱交換器(12)の第２端部に、第３ガス分岐管(33)が第３熱交換器(13)の第２端部に接続されている。膨張機構(6) は、第１液分岐管(21)に設けられた第１膨張機構(41)、第２液分岐管(22)に設けられた第２膨張機構(42)、及び第３液分岐管(23)に設けられた第３膨張機構(43)から構成されている。第２液分岐管(22)における第１液分岐管(21)との接続点と第３液分岐管(23)との接続点との間には第１開閉弁(51)が設けられ、第２液分岐管(22)における第２膨張機構(42)と第２熱交換器(12)との間と、第３液分岐管(23)における第３膨張機構(43)と第３熱交換器(13)との間にはバイパス通路(24)が接続されるとともに該バイパス通路(24)に第２開閉弁(52)が設けられ、第３ガス分岐管(33)における第２ガス分岐管(32)との接続点と第１ガス分岐管(31)との接続点との間には第３開閉弁(53)が設けられている。そして、上記第１開閉弁(51)と第２開閉弁(52)と第３開閉弁(53)とが切換手段(8) を構成している。
【００１７】
この請求項４に記載の発明では、例えば冷房サイクルにおいて第１開閉弁(51)、第２開閉弁(52)、及び第３開閉弁(53)をすべて閉鎖すると、冷媒は第１熱交換器(11)、第３熱交換器(13)、第２熱交換器(12)を順に流れ、室内空気は第１熱交換器(11)で予冷、第２熱交換器(12)で除湿、第３熱交換器(13)で再熱の処理が行われる。これにより、処理効率を高められる。
【００１８】
また、冷房サイクルと暖房サイクルにおいて第１開閉弁(51)と第３開閉弁(53)を開放し、第２開閉弁(52)を閉鎖すると、冷媒は第１，第２，第３熱交換器(13)を並列に流れる。さらに、暖房サイクルにおいて第１開閉弁(51)と第３開閉弁(53)を閉鎖し、第２開閉弁(52)を開放すると、冷媒は第２熱交換器(12)、第３熱交換器(13)、第１熱交換器(11)を順に流れる。これらの冷媒流れを選択すると、冷房運転時や暖房運転時にも効率のよい運転が可能となる。
【００１９】
次に、請求項５及び請求項６に記載の発明は、切換手段(4)(8)による具体的な冷媒流れの別の切り換えの仕方を特定したもので、請求項５に記載の発明は、切換手段(4)(8)が、室内熱交換器(7) を構成する各熱交換器(11,12,13)における冷媒の流れを３種類の直列流れに切り換えるように構成されていることを特徴としている。。
【００２０】
また、請求項６に記載の発明は、請求項５に記載の空気調和装置において、切換手段(4)(8)が、第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を冷媒が順に流れる第１の直列流れと、冷媒が第１熱交換器(11)、第３熱交換器(13)、第２熱交換器(12)を順に流れる第２の直列流れと、冷媒が第３熱交換器(13)、第２熱交換器(12)、第１熱交換器(11)を順に流れる第３の直列流れとを可能にするように構成されていることを特徴とするものである。
【００２１】
これら請求項５及び請求項６の発明では、第１熱交換器(11)から第３熱交換器(13)において冷媒が直列に流れる状態を、３種類のうちから運転状態に応じて適宜選択することが可能となる。特に、請求項６の発明において、冷房運転時に冷媒が第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を順に流れる状態と、除湿運転時に冷媒が第１熱交換器(11)、第３熱交換器(13)、第２熱交換器(12)を順に流れる状態と、暖房運転時に冷媒が第３熱交換器(13)、第２熱交換器(12)、第１熱交換器(11)を順に流れる状態とを選択することにより、各運転時の効率低下を抑えられる。
【００２２】
また、請求項７に記載の発明は、請求項６に記載の空気調和装置において、冷媒回路の構成を特定したものである。すなわち、この発明では、図２及び図３に示すように、冷媒回路(2) における冷媒の循環方向が可逆に構成され、冷媒回路(2) の液側配管(PL)が第１熱交換器(11)の第１端部に第１膨張機構(41)を介して接続され、第２熱交換器(12)の第１端部と第３熱交換器(13)の第１端部に、第２膨張機構(42)と、冷媒が該膨張機構(42)をバイパス可能な第１切換機構(55)とが接続されている。この第２膨張機構(42)と第１切換機構(55)は、例えば電動膨張弁を用いることで両機能を兼用してもよい。また、第１熱交換器(11)、第２熱交換器(12)、及び第３熱交換器(13)の第２端部は、第３熱交換器(13)がガス側配管(PG)の主ガス管(30)と連通し、第１熱交換器(11)と第２熱交換器(12)とが連通する第１状態と、第２熱交換器(12)がガス側配管(PG)の主ガス管(30)と連通し、第１熱交換器(11)と第３熱交換器(13)とが連通する第２状態とを切り換える第２切換機構(56)(57〜60)を介して接続されている。そして、上記第１切換機構(55)と第２切換機構(56)(57〜60)とが切換手段(8) を構成している。
【００２３】
また、請求項８に記載の発明は、請求項７に記載の空気調和装置において、第２切換機構が四路切換弁(56)により構成されていることを特徴とするものである。この四路切換弁(56)は、例えば電動方式で連通状態を切り換えるようにすることができる。
【００２４】
また、請求項９に記載の発明は、請求項７に記載の空気調和装置において、第２切換機構が複数の開閉弁(57〜60)により構成されていることを特徴とするものである。
【００２５】
これら請求項７から請求項９の発明では、第１切換機構(55)と、四路切換弁(56)や複数の開閉弁(57〜60)からなる第２切換機構(56)(57〜60)とを適宜操作することにより、請求項６の発明の３種類の冷媒流れを実現でき、除湿運転時、冷房運転時、暖房運転時のそれぞれで効率のよい運転が可能となる。
【００２６】
【発明の実施の形態１】
以下、本発明の実施形態１を図面に基づいて詳細に説明する。
【００２７】
図１は、この実施形態１に係る空気調和装置(1) の冷媒回路図である。この空気調和装置(1) の冷媒回路(2) は、圧縮機(3) と、四路切換弁(4) と、室外熱交換器(5) と、膨張機構(6) と、室内熱交換器(7) とを順に接続することにより構成されている。
【００２８】
上記冷媒回路(2) において、圧縮機(3) の吐出側は、四路切換弁（切換手段）(4) の第１ポート(P1)に接続され、四路切換弁(4) の第２ポート(P2)は室外熱交換器(5) のガス側に接続されている。また、四路切換弁(4) の第３ポート(P3)は室内熱交換器(7) のガス側に接続され、四路切換弁(4) の第４ポート(P4)は圧縮機(3) の吸入側に接続されている。
【００２９】
上記四路切換弁(4) は、第１ポート(P1)と第２ポート(P2)が連通し、第３ポート(P3)と第４ポート(P4)が連通する第１の連通状態（図１の実線の連通状態）と、第１ポート(P1)と第３ポート(P3)が連通し、第２ポート(P2)と第４ポート(P4)が連通する第２の連通状態（図１の破線の連通状態）とを切り換えることにより、冷媒回路(2) における冷房サイクルの運転と暖房サイクルの運転とを可能にしている。つまり、この冷媒回路(2) は冷媒の循環方向が可逆に構成されている。
【００３０】
上記室内熱交換器(7) は、空気流れの上流側から下流側へ順に配設された第１熱交換器(11)、第２熱交換器(12)及び第３熱交換器(13)から構成されている。これら熱交換器(11,12,13)は、各熱交換器(11,12,13)における冷媒の流れを切り換える切換手段(8) を介して冷媒回路(2) の液側配管(PL)及びガス側配管(PG)に接続されている。
【００３１】
具体的に、冷媒回路(2) の液側配管(PL)は、主液管(20)から分岐した第１液分岐管(21)及び第２液分岐管(22)と、該第２液分岐管(22)から分岐した第３液分岐管(23)とを備えている。そして、第１液分岐管(21)が第１熱交換器(11)の第１端部に、第２液分岐管(22)が第２熱交換器(12)の第１端部に、第３液分岐管(23)が第３熱交換器(13)の第１端部に接続されている。
【００３２】
また、冷媒回路(2) のガス側配管(PG)は、主ガス管(30)から分岐した第２ガス分岐管(32)及び第３ガス分岐管(33)と、該第３ガス分岐管(33)から分岐した第１ガス分岐管(31)とを備えている。そして、第１ガス分岐管(31)が第１熱交換器(11)の第２端部に、第２ガス分岐管(32)が第２熱交換器(12)の第２端部に、第３ガス分岐管(33)が第３熱交換器(13)の第２端部に接続されている。
【００３３】
上記膨張機構(6) は、第１液分岐管(21)に設けられた第１膨張機構(41)と、第２液分岐管(22)に設けられた第２膨張機構(42)と、第３液分岐管(23)に設けられた第３膨張機構(43)とから構成されている。各膨張機構(41,42,43)としては、キャピラリチューブを用いたり、膨張弁を用いたりすることが可能であるが、本発明の実施に当たっては、様々な運転状態に対応して冷媒の減圧度を調整するために、電子膨張弁など、開度調整可能な膨張弁を用いるとよい。
【００３４】
上記切換手段(8) として、この実施形態１では複数の電磁弁（開閉弁）(51,52,53)が設けられている。具体的には、第２液分岐管(22)における第１液分岐管(21)との接続点と第３液分岐管(23)との接続点との間に、第１電磁弁（第１開閉弁）(51)が設けられている。また、第２液分岐管(22)における第２膨張機構(42)と第２熱交換器(12)との間と、第３液分岐管(23)における第３膨張機構(43)と第３熱交換器(13)との間に接続されたバイパス通路(24)に、第２電磁弁（第２開閉弁）(52)が設けられている。さらに、第３ガス分岐管(33)における第２ガス分岐管(32)との接続点と第１ガス分岐管(31)との接続点との間に、第３電磁弁（第３開閉弁）(53)が設けられている。
【００３５】
上記冷媒回路(2) は、これら電磁弁(51,52,53)からなる切換手段(8) を設けたことにより、室内熱交換器(7) を構成する各熱交換器(11,12,13)における冷媒の流れを直列と並列に切り換えることが可能となっている。また、上記切換手段(8) により、直列流れと並列流れのいずれも冷媒の流れ方向が可逆になっている。直列流れについては、冷媒が第１熱交換器(11)、第３熱交換器(13)、第２熱交換器(12)を順に流れる直列流れと、第２熱交換器(12)、第３熱交換器(13)、第１熱交換器(11)を順に流れる直列流れとが可能に構成されている。
【００３６】
−運転動作−
次に、この空気調和装置の運転動作について説明する。
【００３７】
まず、冷房運転時は、四路切換弁(4) を実線で示す第１の連通状態にセットし、第１電磁弁(51)と第３電磁弁(53)を開放し、第２電磁弁(52)を閉鎖する制御を行う。この状態で圧縮機(3) を起動すると、圧縮機(3) から吐出された冷媒は、四路切換弁(4) を通って室外熱交換器(5) へ流入し、該室外熱交換器(5) において室外空気と熱交換を行って凝縮する。室外熱交換器(5) から流出した液冷媒は主液管(20)を通って室内側へ流れ、各液分岐管(21,22,23)に分岐する。
【００３８】
液冷媒は各液分岐管(21,22,23)の膨張機構(41,42,43)において減圧されて膨張し、各室内熱交換器(11,12,13)へ並列に流入する。ここでは、第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を順に通過する室内空気と冷媒とが熱交換を行い、冷媒が蒸発するとともに、室内空気が順次効率よく冷却されて室内へ還気される。その後、冷媒は第１ガス分岐管(31)、第２ガス分岐管(32)、第３ガス分岐管(33)を通って主ガス管(30)で合流し、四路切換弁(4) を介して圧縮機(3) に吸入される。以上のようにして冷媒が循環を繰り返すことにより、室内が冷房される。
【００３９】
次に、除湿運転時は、四路切換弁(4) を実線で示す第１の連通状態にセットし、第１電磁弁(51)、第２電磁弁(52)、及び第３電磁弁(53)をすべて閉鎖する制御を行う。この状態で圧縮機(3) を起動すると、圧縮機(3) から吐出された冷媒は、冷房運転時と同様に四路切換弁(4) を通って室外熱交換器(5) へ流入し、該室外熱交換器(5) において室外空気と熱交換を行って凝縮する。室外熱交換器(5) から流出した液冷媒は主液管(20)を通り、第１膨張機構(41)で中間圧に減圧され、第１熱交換器(11)へ流入する。
【００４０】
冷媒は第１熱交換器(11)と第３熱交換器(13)を順に通過し、中間圧で蒸発する。その後、冷媒は第３膨張機構(43)と第２膨張機構(42)を通るときに所定の低圧圧力に減圧され、さらに第２熱交換器(12)で蒸発する。室内熱交換器(7) を流れる空気は、まず第１熱交換器(11)で中間圧の冷媒がある程度加熱されるときに予冷され、第２熱交換器(12)では低圧の冷媒が加熱されるときに主に除湿された後、第３熱交換器(13)では第１熱交換器で加熱された冷媒により再熱されて室内に還気される。この除湿運転時は、潜熱処理が効率的に行われる。
【００４１】
また、暖房運転時は、四路切換弁(4) を破線で示す第２の連通状態にセットし、第１電磁弁(51)と第３電磁弁(53)を開放し、第２電磁弁(52)を閉鎖する制御を行う。この状態で圧縮機(3) を起動すると、圧縮機(3) から吐出された冷媒は、四路切換弁(4) を通って室内側へ流れ、各ガス分岐管(31,32,33)に分岐して各室内熱交換器(11,12,13)へ並列に流入する。ここでは、第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を順に通過する室内空気と冷媒とが熱交換を行い、冷媒が凝縮するとともに、室内空気が順次効率よく加熱されて室内へ還気される。
【００４２】
その後、冷媒は第１液分岐管(21)、第２液分岐管(22)、第３ガス分岐管(23)を流れる際に各膨張機構(41,42,43)で減圧されて膨張し、さらに主液管(20)で合流した後に室外熱交換器(5) に流入する。室外熱交換器(5) では、冷媒が室外空気と熱交換して蒸発し、ガス相に変化する。その後、冷媒は四路切換弁(4) を通って圧縮機(3) に吸入され、暖房運転の１サイクルが完了する。そして、以上の暖房サイクルが連続的に繰り返され、室内が暖房される。
【００４３】
この実施形態１では、暖房運転時には、冷媒の循環状態を直列に切り換えることも可能である。このときには、第１電磁弁(51)と第３電磁弁(53)が閉鎖され、第２電磁弁(52)が開放される。したがって、圧縮機(3) から主ガス管(30)を流れてきた冷媒は、第２熱交換器(12)、第３熱交換器(13)、及び第１熱交換器(11)を順に流れる際に凝縮し、さらに第１膨張機構(41)で膨張した後に室外熱交換器(5) へ流れていく。
【００４４】
−実施形態１の効果−
この実施形態１によれば、室内熱交換器(7) を構成している第１熱交換器(11)、第２熱交換器(12)、及び第３熱交換器(13)において、冷媒の流れる方向や順序を切り換えるようにしているため、除湿運転時を始め、冷房運転時や暖房運転時にも運転効率のよい冷媒流れを選択することが可能となる。これにより、除湿運転時は効率がよくても冷房運転時や暖房運転時には効率が低下するといった従来の問題を回避でき、空気調和装置(1) としてのトータルの運転効率を高めることが可能となる。
【００４５】
特に、除湿運転時に冷媒が第１熱交換器(11)、第３熱交換器(13)、及び第２熱交換器(12)を順に流れる直列流れと、冷房運転時と暖房運転時に互いに逆向きの並列流れとを選択できるようにしており、且つ暖房運転時にはさらに除湿運転時とは逆向きの直列流れも選択できるようにしているので、各運転時の効率低下を効果的に防止でき、それによって空気調和装置としてのトータルの運転効率を確実に高められる。
【００４６】
さらに、この実施形態１では複数の電磁弁(51,52,53)を用いるだけで上記効果を実現できるようにしているため、装置のコストアップも防止できる。
【００４７】
【発明の実施の形態２】
本発明の実施形態２は、図２に示すように、冷媒回路(2) における室内側の第１熱交換器(11)、第２熱交換器(12)及び第３熱交換器(13)の接続態様を実施形態１とは変更した例である。以下、実施形態１と異なる部分について説明する。
【００４８】
この実施形態２では、切換手段(8) は、室内熱交換器(7) を構成する各熱交換器(11,12,13)における冷媒の流れを３種類の直列流れに切り換えるように構成されている。さらに詳細にいうと、切換手段(8) は、冷媒が第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を順に流れる第１の直列流れと、冷媒が第１熱交換器(11)、第３熱交換器(13)、第２熱交換器(12)を順に流れる第２の直列流れと、冷媒が第３熱交換器(13)、第２熱交換器(12)、第１熱交換器(11)を順に流れる第３の直列流れとを可能にするように構成されている。
【００４９】
このため、冷媒回路(2) の液側配管(PL)は、第１熱交換器(11)の第１端部に第１膨張機構(41)を介して接続されている。また、第２熱交換器(12)の第１端部と第３熱交換器(13)の第１端部には、第２膨張機構(42)と、冷媒に該膨張機構(42)をバイパスさせるための液側電磁弁（第１切換機構）(55)とが接続されている。この実施形態２においては、第２膨張機構(42)と液側電磁弁(55)とを並列に接続しているが、電子膨張弁などの開度調整可能な膨張弁を用いることにより、該膨張弁が開閉弁の機能を兼ね備えるものとしてもよい。
【００５０】
第１熱交換器(11)、第２熱交換器(12)、及び第３熱交換器(13)の第２端部と、ガス側配管(PG)の主ガス管(30)とは、例えばスプールの位置が電動で切り換わって連通状態が変化する第２四路切換弁(56)（以下、この実施形態２において、四路切換弁(4) は第１四路切換弁(4) という）を介して、互いに接続されている。上記第２四路切換弁(56)は、第３熱交換器(13)が主ガス管(30)と連通し、第１熱交換器(11)と第２熱交換器(12)とが連通する第１状態と、第２熱交換器(12)が主ガス管(30)と連通し、第１熱交換器(11)と第３熱交換器(13)とが連通する第２状態とを切り換える第２切換機構を構成している。
【００５１】
具体的には、第１ガス分岐管(31)が第２四路切換弁(56)の第１ポート(P1)に接続され、第２ガス分岐管(32)が第２四路切換弁(56)の第２ポート(P2)に接続されている。また、第３ガス分岐管(33)が第２四路切換弁(56)の第３ポート(P3)に接続され、主ガス管(30)が第２四路切換弁(56)の第４ポート(P4)に接続されている。この第２四路切換弁(56)は、第１ポート(P1)と第２ポート(P2)が連通し、第３ポート(P3)と第４ポート(P4)が連通する第１の連通状態（図２の実線の連通状態）と、第１ポート(P1)と第３ポート(P3)が連通し、第２ポート(P2)と第４ポート(P4)が連通する第２の連通状態（図２の破線の連通状態）とを切り換えることができるように構成されている。
【００５２】
−運転動作−
次に、この実施形態２の空気調和装置(1) における運転動作を説明する。
【００５３】
まず、冷房運転時は、第１四路切換弁(4) を実線で示す第１の連通状態にセットし、第２四路切換弁(56)を第１の連通状態にセットする。また、液側電磁弁(55)を開放する制御を行う。この状態で圧縮機(3) を起動すると、圧縮機(3) から吐出された冷媒は、四路切換弁(4) を通って室外熱交換器(5) へ流入し、該室外熱交換器(5) において室外空気と熱交換を行って凝縮する。
【００５４】
室外熱交換器(5) から流出した液冷媒は主液管(20)を通って室内側へ流れ、第１膨張機構(41)において膨張した後に、第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を順に流れていく。ここでは、第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を順に通過する室内空気と冷媒とが熱交換を行い、冷媒が蒸発するとともに、室内空気が効率よく冷却されて室内へ還気される。その後、冷媒は第３ガス分岐管(33)から第２四路切換弁(56)、主ガス管(30)、及び第１四路切換弁(4) を介して圧縮機(3) に吸入され、冷房運転の１サイクルが完了する。そして、以上の冷房サイクルが連続的に繰り返され、効率のよい冷房運転が行われる。
【００５５】
除湿運転時は、第１四路切換弁(4) を実線の第１の連通状態にセットし、第２四路切換弁(56)を破線で示す第２の連通状態にセットし、さらに液側電磁弁(55)を閉鎖する制御を行う。この状態で圧縮機(3) を起動すると、圧縮機(3) から吐出された冷媒は、冷房運転時と同様に四路切換弁(4) を通って室外熱交換器(5) へ流入し、該室外熱交換器(5) において室外空気と熱交換を行って凝縮する。室外熱交換器(5) から流出した液冷媒は主液管(20)を通り、第１膨張機構(41)で中間圧に減圧膨張した後、第１熱交換器(11)へ流入する。
【００５６】
液冷媒は第１熱交換器(11)と第３熱交換器(13)を順に通過し、中間圧で蒸発する。その後、冷媒は第２膨張機構(42)で所定の低圧圧力に減圧され、第２熱交換器(12)で蒸発する。室内熱交換器(7) を流れる空気は、まず第１熱交換器(11)で予冷され、第２熱交換器(12)で主に除湿された後、第３熱交換器(13)で再熱されて室内に還気される。
【００５７】
一方、暖房運転時は、四路切換弁(4) を破線の第２の連通状態にセットし、第２四路切換弁(56)を第１の連通状態にセットし、電磁弁(55)を開放する制御を行う。この状態で圧縮機(3) を起動すると、圧縮機(3) から吐出された冷媒は、第１四路切換弁(4) 及び第２四路切換弁(56)を通って室内側へ流れ、第３熱交換器(13)、第２熱交換器(12)、第１熱交換器(11)を順に通過する際に凝縮する。このとき、冷媒は第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を順に流れる室内空気と熱交換して効率よく加熱され、室内に還気される。第１熱交換器(11)から流出した液冷媒は、第１膨張機構(41)で減圧膨張し、室外熱交換器(5) で蒸発する。その後、冷媒は第１四路切換弁(4) を介して圧縮機(3) に吸入され、以上の循環動作が繰り返される。
【００５８】
−実施形態２の効果−
この実施形態２によれば、第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を冷媒が順に流れる第１の直列流れと、冷媒が第１熱交換器(11)、第３熱交換器(13)、第２熱交換器(12)を順に流れる第２の直列流れと、冷媒が第３熱交換器(13)、第２熱交換器(12)、第１熱交換器(11)を順に流れる第３の直列流れを切り換えられるようにしたことにより、冷房運転時、除湿運転時、暖房運転時のそれぞれで効率のよい冷媒流れを選択することができ、空気調和装置のトータルの運転効率を高められる。
【００５９】
また、上記の冷媒流れを切り換えるために液側電磁弁(55)と第２四路切換弁(56)だけを用いているため、装置(1) の大幅なコストアップも抑えられる。
【００６０】
【発明の実施の形態３】
本発明の実施形態３は、図３に示すように、実施形態２の第２四路切換弁(56)に変えて複数の開閉弁を用いることにより、該第２四路切換弁(56)と同じ機能を実現したものである。
【００６１】
具体的に、主ガス管(30)は、第１ガス分岐管(31)を介して第１熱交換器(11)に、第２ガス分岐管(32)を介して第２熱交換器(12)に、そして第３ガス分岐管(33)を介して第３熱交換器(13)に接続されている。第１ガス分岐管(31)は、第２ガス分岐管(32)と第３ガス分岐管(33)との接続点よりも第３熱交換器(13)側で、第３ガス分岐管(33)から分岐している。
【００６２】
第１ガス分岐管(31)は、ガス側第１電磁弁(57)が設けられ、第３ガス分岐管(33)に接続されている。また、第２ガス分岐管(32)は、ガス側第２電磁弁(58)が設けられ、第３ガス分岐管(33)に接続されている。第３ガス分岐管(33)には、該第３ガス分岐管(33)と第２ガス分岐管(32)との接続点と、第３ガス分岐管(33)と第１ガス分岐管(31)との接続点との間に、ガス側第３電磁弁(59)が設けられている。第１ガス分岐管(31)と第２ガス分岐管(32)は、第１ガス分岐管(31)における第１熱交換器(11)とガス側第１電磁弁(57)の間と、第２ガス分岐管(32)における第２熱交換器(12)とガス側第２電磁弁(58)との間が、ガス側第４電磁弁(60)を介して接続されている。
【００６３】
この実施形態において、冷房運転時は、四路切換弁(4) が第１の連通状態にセットされ、ガス側第１電磁弁(57)、ガス側第２電磁弁(58)が閉鎖され、ガス側第３電磁弁(59)、ガス側第４電磁弁(60)が開放される。こうすることにより、冷媒が実施形態２と同様に第１熱交換器(11)、第２熱交換器(12)、及び第３熱交換器(13)を順に流れて室内空気が効率よく冷却される。
【００６４】
除湿運転時は、ガス側第１電磁弁(57)、ガス側第２電磁弁(58)が開放され、ガス側第３電磁弁(59)、ガス側第４電磁弁(60)が閉鎖される。こうすることにより、冷媒が実施形態２と同様に第１熱交換器(11)、第３熱交換器(13)、及び第２熱交換器(12)を順に流れて室内空気が効率よく除湿される。
【００６５】
また、暖房運転時は、ガス側第１電磁弁(57)、ガス側第２電磁弁(58)が閉鎖され、ガス側第３電磁弁(59)、ガス側第４電磁弁(60)が開放される。こうすることにより、冷媒が実施形態２と同様に第３熱交換器(13)、第２熱交換器(12)、及び第１熱交換器(11)を順に流れて室内空気が効率よく加熱される。
【００６６】
この実施形態３においても実施形態２と同じ冷媒流れを実現できるため、冷房、除湿、暖房の各運転時の効率低下を抑えることができ、空気調和装置(1) のトータルの運転効率を高められる。また、切換手段(8) を複数の電磁弁(55)(57〜60)から構成しているため、装置の大幅なコストアップも抑えられる。
【００６７】
【発明の効果】
請求項１に記載の発明によれば、室内熱交換器(7) を構成する第１熱交換器(11)、第２熱交換器(12)、及び第３熱交換器(13)において、上記切換手段(4)(8)により冷媒の流れる方向や順序を切り換えることにより、除湿運転時を始め、冷房運転時や暖房運転時にも効率のよい冷媒流れを選択することが可能となるため、除湿運転時は効率がよくても冷房運転時や暖房運転時には効率が低下するといった従来の問題を回避でき、空気調和装置(1) としてのトータルの運転効率を高めることが可能となる。
【００６８】
また、請求項１から請求項３に記載の発明によれば、第１熱交換器(11)から第３熱交換器(13)において冷媒が直列に流れる状態や並列に流れる状態を運転状態に応じて適宜選択することにより、空気調和装置(1) としてのトータルの運転効率を確実に高められる。特に、請求項３の発明によれば、除湿運転時に冷媒が第１熱交換器(11)、第３熱交換器(13)、第２熱交換器(12)を順に（直列に）流れる状態を選択し、冷房運転時や暖房運転時に冷媒が各熱交換器(11,12,13)を並列に流れる状態を選択することにより、その効果を確実にすることができる。
【００６９】
また、請求項４に記載の発明によれば、冷媒回路の構成を特定し、除湿運転時に処理効率のよい冷媒流れと、冷房運転時や暖房運転時に効率のよい冷媒流れを選択できるようにしているので、空気調和装置(1) のトータルの運転効率を確実に高められる。また、複数の開閉弁(51,52,53)を用いるだけで上記効果を実現でき、装置(1) のコストアップも抑えられる。
【００７０】
また、請求項５及び請求項６に記載の発明によれば、第１熱交換器(11)、第２熱交換器(12)及び第３熱交換器(13)において冷媒が直列に流れる状態を、３種類のうちから運転状態に応じて適宜選択することにより、空気調和装置(1) としてのトータルの運転効率を確実に高められる。特に、請求項６の発明によれば、冷房運転時に冷媒が第１熱交換器(11)、第２熱交換器(12)、第３熱交換器(13)を順に流れる状態と、除湿運転時に冷媒が第１熱交換器(11)、第３熱交換器(13)、第３熱交換器(13)を順に流れる状態と、暖房運転時に冷媒が第３熱交換器(13)、第２熱交換器(12)、第１熱交換器(11)を順に流れる状態とを選択することにより、その効果を確実にすることができる。
【００７１】
また、請求項７から請求項９に記載の発明によれば、四路切換弁(56)や複数の開閉弁(57〜60)からなる第２切換機構と、第１切換機構(55)とを適宜操作して、請求項６の発明の３種類の冷媒流れを実現することにより、冷房運転時、除湿運転時、暖房運転時のそれぞれで効率のよい運転が可能となり、空気調和装置(1) としてのトータルの運転効率を高められる。また、特に請求項８及び請求項９の発明によれば四路切換弁(56)や複数の開閉弁(57〜60)を用いるだけで上記効果を実現できるため、装置のコストアップも抑えられる。
【図面の簡単な説明】
【図１】本発明の実施形態１に係る空気調和装置の冷媒回路図である。
【図２】本発明の実施形態２に係る空気調和装置の冷媒回路図である。
【図３】本発明の実施形態３に係る空気調和装置の冷媒回路図である。
【符号の説明】
(1) 空気調和装置
(2) 冷媒回路
(3) 圧縮機
(5) 室外熱交換器
(6) 膨張機構
(7) 室内熱交換器
(8) 切換手段
(11) 第１熱交換器
(12) 第２熱交換器
(13) 第３熱交換器
(20) 主液管
(21) 第１液分岐管
(22) 第２液分岐管
(23) 第３液分岐管
(24) バイパス通路
(30) 主ガス管
(31) 第１ガス分岐管
(32) 第２ガス分岐管
(33) 第３ガス分岐管
(41) 第１膨張機構
(42) 第２膨張機構
(43) 第３膨張機構
(51) 第１開閉弁
(52) 第２開閉弁
(53) 第３開閉弁
(55) 液側電磁弁（開閉弁、第１切換機構）
(56) 第２四路切換弁（第２切換機構）
(57〜59) ガス側電磁弁（開閉弁、第２切換機構）
(PL) 液側配管
(PG) ガス側配管[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an air conditioner, and particularly relates to an air conditioner capable of dehumidifying operation.
[0002]
[Prior art]
  2. Description of the Related Art Conventionally, as a method of dehumidifying operation in an air conditioner, a method is known in which air dehumidified and cooled by an indoor heat exchanger is heated (reheated) to suppress the temperature drop of the blown air. However, in this type of air conditioner, there is room for improvement in energy saving because the amount of sensible heat treatment in the indoor heat exchanger is relatively large.
[0003]
  Then, in order to improve the processing efficiency at the time of a dehumidification operation, the air conditioning apparatus which comprised the indoor heat exchanger with the three heat exchangers is proposed (for example, refer patent document 1). In the air conditioner of Patent Document 1, the indoor heat exchanger includes a first heat exchanger, a second heat exchanger, and a third heat exchanger that are sequentially arranged from the upstream side to the downstream side of the air passage. Has been.
[0004]
  In this air conditioner, during the dehumidifying operation, in the refrigerant circuit, in the order of the compressor, the condenser, the intermediate pressure expansion valve, the first heat exchanger, the third heat exchanger, the expansion valve, and the second heat exchanger. Refrigeration cycle is performed by circulating refrigerant. At this time, the refrigerant evaporates at an intermediate pressure in the first heat exchanger. At that time, the air is cooled (precooled) and then flows into the third heat exchanger to heat (re-return) the air returned to the room. heat. The refrigerant flowing into the second heat exchanger from the third heat exchanger is sucked into the compressor after the air that has passed through the first heat exchanger is cooled and evaporated. According to this refrigerant circuit, during the dehumidifying operation, the room air pre-cooled by the first heat exchanger passes through the second heat exchanger, so the amount of sensible heat treatment is reduced, and a dehumidifying operation with high latent heat treatment efficiency is possible.
[0005]
[Patent Document 1]
        JP 2001-147032 A
[0006]
[Problems to be solved by the invention]
  On the other hand, when performing the heating operation with the air conditioner, the refrigerant flows in order through the second heat exchanger, the third heat exchanger, and the first heat exchanger by reversing the refrigerant circulation direction in the refrigerant circuit. become. At this time, the room air sequentially passes through the first heat exchanger, the second heat exchanger, and the third heat exchanger. In the cooling operation, the control of the expansion valve is different, but the refrigerant and air flows themselves are the same as in the dehumidifying operation.
[0007]
  However, considering the operating efficiency during heating operation or cooling operation, it may be preferable to flow the refrigerant in parallel to the three heat exchangers or even in a different order than in the dehumidifying operation. . That is, in the refrigerant circuit of Patent Document 1, the relationship between the refrigerant flow and the air flow cannot be optimized during the cooling operation or the heating operation, and the total operation efficiency as the air conditioner may be reduced. .
[0008]
  The present invention was devised in view of such problems, and an object of the present invention is to reduce operating efficiency during dehumidifying operation in an air conditioner including three heat exchangers on the indoor side. It is to prevent the operation efficiency from being lowered during cooling operation and heating operation.
[0009]
[Means for Solving the Problems]
  The present invention is configured so that the refrigerant flow in the three heat exchangers (11, 12, 13) constituting the indoor heat exchanger (7) can be switched between a cooling operation, a heating operation, and a dehumidifying operation. Switching means (4) and (8) are provided before and after the exchanger (11, 12, 13).
[0010]
  Specifically, the invention described in claim 1 is a refrigerant circuit (2) in which a compressor (3), an outdoor heat exchanger (5), an expansion mechanism (6), and an indoor heat exchanger (7) are connected in order. ), And the indoor heat exchanger (7) is disposed in order from the upstream side to the downstream side of the air flow, the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger ( It is assumed that the air conditioner is composed of 13). The air conditioner includes switching means (4) (8) for switching the refrigerant flow in each heat exchanger (11, 12, 13) constituting the indoor heat exchanger (7).I have.
[0011]
  In the first aspect of the invention, in the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13), which are indoor heat exchangers (7), the switching means ( 4) By (8), it becomes possible to switch the flow direction and order of the refrigerant. For this reason, it becomes possible to select an efficient refrigerant flow not only during dehumidification operation but also during cooling operation or heating operation.
[0012]
  Claims 1 to 3The invention described in the above is a specific method of switching the refrigerant flow by the switching means (4) (8),The invention described in claim 1The switching means (4) (8) is configured to switch the refrigerant flow in each heat exchanger (11, 12, 13) constituting the indoor heat exchanger (7) in series and in parallel. It is said.
[0013]
  Also,Claim 2The invention described inClaim 1In the air conditioner described in (4), the switching means (4) (8) switches the refrigerant flow in each heat exchanger (11, 12, 13) constituting the indoor heat exchanger (7) in series and in parallel. The reversible refrigerant flow is possible in at least one of series and parallel.
[0014]
  Also,Claim 3The invention described inClaim 2In the air conditioning apparatus according to claim 1, the switching means (4) and (8) are connected in series through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12). It is configured to enable a flow and a reversible parallel flow.
[0015]
  theseClaims 1 to 3In this invention, in the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13), the state in which the refrigerant flows in series or in parallel is appropriately selected according to the operating state. It becomes possible to do. In particular,Claim 3In this invention, the refrigerant flows through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12) in order (in series) during the dehumidifying operation, and during the cooling operation and heating. By selecting a state in which the refrigerant flows in parallel through the heat exchangers (11, 12, 13) during operation, a decrease in efficiency during each operation can be suppressed.
[0016]
  Also,Claim 4The invention described inClaim 3In the air conditioning apparatus described above, the configuration of the refrigerant circuit is specified. That is, in the present invention, as shown in FIG. 1, the refrigerant circulation direction in the refrigerant circuit (2) is configured to be reversible, and the liquid side pipe (PL) of the refrigerant circuit (2) is connected to the main liquid pipe (20). The first liquid branch pipe (21) and the second liquid branch pipe (22) branched and a third liquid branch pipe (23) branched from the second liquid branch pipe (22) are provided. The pipe (21) is at the first end of the first heat exchanger (11), the second liquid branch pipe (22) is at the first end of the second heat exchanger (12), and the third liquid branch pipe ( 23) is connected to the first end of the third heat exchanger (13). The gas side pipe (PG) of the refrigerant circuit (2) includes a second gas branch pipe (32) and a third gas branch pipe (33) branched from the main gas pipe (30), and the third gas branch pipe. A first gas branch pipe (31) branched from (33), and the first gas branch pipe (31) is provided at the second end of the first heat exchanger (11) at the second gas branch pipe (32). ) Is connected to the second end of the second heat exchanger (12), and the third gas branch pipe (33) is connected to the second end of the third heat exchanger (13). The expansion mechanism (6) includes a first expansion mechanism (41) provided in the first liquid branch pipe (21), a second expansion mechanism (42) provided in the second liquid branch pipe (22), and a third It is comprised from the 3rd expansion mechanism (43) provided in the liquid branch pipe (23). A first on-off valve (51) is provided between a connection point of the second liquid branch pipe (22) with the first liquid branch pipe (21) and a connection point of the third liquid branch pipe (23), Between the second expansion mechanism (42) and the second heat exchanger (12) in the second liquid branch pipe (22), and between the third expansion mechanism (43) and the third heat in the third liquid branch pipe (23). A bypass passage (24) is connected to the exchanger (13), and a second on-off valve (52) is provided in the bypass passage (24), and the second gas in the third gas branch pipe (33) is provided. A third on-off valve (53) is provided between the connection point with the branch pipe (32) and the connection point with the first gas branch pipe (31). The first on-off valve (51), the second on-off valve (52) and the third on-off valve (53) constitute a switching means (8).
[0017]
  thisClaim 4In the invention described in 1), for example, when the first on-off valve (51), the second on-off valve (52), and the third on-off valve (53) are all closed in the cooling cycle, the refrigerant is the first heat exchanger (11), It flows through the third heat exchanger (13) and the second heat exchanger (12) in this order, and the indoor air is pre-cooled by the first heat exchanger (11), dehumidified by the second heat exchanger (12), and third heat exchange Reheating is performed in the vessel (13). Thereby, processing efficiency can be improved.
[0018]
  Further, when the first on-off valve (51) and the third on-off valve (53) are opened and the second on-off valve (52) is closed in the cooling cycle and the heating cycle, the refrigerant exchanges the first, second, and third heats. Flows in parallel (13). Further, when the first on-off valve (51) and the third on-off valve (53) are closed and the second on-off valve (52) is opened in the heating cycle, the refrigerant becomes the second heat exchanger (12) and the third heat exchange. It flows through the heat exchanger (13) and the first heat exchanger (11) in this order. When these refrigerant flows are selected, efficient operation is possible even during cooling operation or heating operation.
[0019]
  next,Claims 5 and 6The invention described in the above specification specifies another way of switching the concrete refrigerant flow by the switching means (4) and (8).The invention described in claim 5The switching means (4) and (8) are configured to switch the refrigerant flow in each of the heat exchangers (11, 12, 13) constituting the indoor heat exchanger (7) into three types of serial flows. It is characterized by. .
[0020]
  Also,Claim 6The invention described inClaim 5In the air conditioner described in 1), the switching means (4) and (8) are configured so that the refrigerant flows in order through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13). 1 serial flow, the second serial flow in which the refrigerant flows through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12) in this order, and the refrigerant in the third heat exchange It is comprised so that the 3rd serial flow which flows through a heat exchanger (13), a 2nd heat exchanger (12), and a 1st heat exchanger (11) in order may be enabled.
[0021]
  theseClaims 5 and 6In this invention, the state in which the refrigerant flows in series in the first heat exchanger (11) to the third heat exchanger (13) can be appropriately selected from the three types according to the operating state. In particular,Claim 6In this invention, the refrigerant flows through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) in this order during the cooling operation, and the first heat exchange during the dehumidifying operation. A state in which the refrigerant flows through the heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12) in this order, and the refrigerant flows through the third heat exchanger (13) and the second heat exchanger (12) during heating operation. By selecting the state of flowing through the first heat exchanger (11) in order, the efficiency drop during each operation can be suppressed.
[0022]
  Also,Claim 7The invention described inClaim 6In the air conditioning apparatus described above, the configuration of the refrigerant circuit is specified. That is, in the present invention, as shown in FIGS. 2 and 3, the refrigerant circulation direction in the refrigerant circuit (2) is configured to be reversible, and the liquid side pipe (PL) of the refrigerant circuit (2) is the first heat exchanger. The first end of (11) is connected via a first expansion mechanism (41) to the first end of the second heat exchanger (12) and the first end of the third heat exchanger (13). The second expansion mechanism (42) is connected to the first switching mechanism (55) that allows the refrigerant to bypass the expansion mechanism (42). The second expansion mechanism (42) and the first switching mechanism (55) may have both functions by using, for example, an electric expansion valve. The second end of the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) is connected to the gas side pipe (PG) by the third heat exchanger (13). ) In the first state where the first heat exchanger (11) and the second heat exchanger (12) communicate with each other, and the second heat exchanger (12) is connected to the gas side pipe. The second switching mechanism (56) (57) that switches between the second state in which the first heat exchanger (11) and the third heat exchanger (13) communicate with each other and communicates with the main gas pipe (30) of (PG). ~ 60) are connected. The first switching mechanism (55) and the second switching mechanism (56) (57-60) constitute switching means (8).
[0023]
  Also,Claim 8The invention described inClaim 7In the air conditioning apparatus described in (1), the second switching mechanism is constituted by a four-way switching valve (56). The four-way switching valve (56) can be switched in the communication state by an electric method, for example.
[0024]
  Also,Claim 9The invention described inClaim 7In the air conditioning apparatus described in (1), the second switching mechanism includes a plurality of on-off valves (57 to 60).
[0025]
  theseClaims 7 to 9In the present invention, the first switching mechanism (55) and the second switching mechanism (56) (57-60) including the four-way switching valve (56) and the plurality of on-off valves (57-60) are appropriately operated. ByClaim 6The three types of refrigerant flow of the present invention can be realized, and efficient operation is possible in each of the dehumidifying operation, the cooling operation, and the heating operation.
[0026]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1
  Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.
[0027]
  FIG. 1 is a refrigerant circuit diagram of the air-conditioning apparatus (1) according to the first embodiment. The refrigerant circuit (2) of the air conditioner (1) includes a compressor (3), a four-way switching valve (4), an outdoor heat exchanger (5), an expansion mechanism (6), and an indoor heat exchange. It is configured by connecting the devices (7) in order.
[0028]
  In the refrigerant circuit (2), the discharge side of the compressor (3) is connected to the first port (P1) of the four-way switching valve (switching means) (4), and the second side of the four-way switching valve (4). The port (P2) is connected to the gas side of the outdoor heat exchanger (5). The third port (P3) of the four-way selector valve (4) is connected to the gas side of the indoor heat exchanger (7), and the fourth port (P4) of the four-way selector valve (4) is connected to the compressor (3 ) Connected to the suction side.
[0029]
  The four-way selector valve (4) is in a first communication state in which the first port (P1) and the second port (P2) communicate with each other, and the third port (P3) and the fourth port (P4) communicate with each other (see FIG. 1 solid line communication state), the first port (P1) and the third port (P3) communicate with each other, and the second port (P2) and the fourth port (P4) communicate with each other (FIG. 1). The operation of the cooling cycle and the operation of the heating cycle in the refrigerant circuit (2) are made possible by switching the communication state of the broken line (2). That is, the refrigerant circuit (2) is configured so that the circulation direction of the refrigerant is reversible.
[0030]
  The indoor heat exchanger (7) includes a first heat exchanger (11), a second heat exchanger (12), and a third heat exchanger (13) arranged in order from the upstream side to the downstream side of the air flow. It is composed of These heat exchangers (11, 12, 13) are connected to the liquid side pipe (PL) of the refrigerant circuit (2) via switching means (8) for switching the refrigerant flow in each heat exchanger (11, 12, 13). And gas side piping (PG).
[0031]
  Specifically, the liquid side pipe (PL) of the refrigerant circuit (2) includes a first liquid branch pipe (21) and a second liquid branch pipe (22) branched from the main liquid pipe (20), and the second liquid. A third liquid branch pipe (23) branched from the branch pipe (22). The first liquid branch pipe (21) is at the first end of the first heat exchanger (11), and the second liquid branch pipe (22) is at the first end of the second heat exchanger (12). A third liquid branch pipe (23) is connected to the first end of the third heat exchanger (13).
[0032]
  The gas side pipe (PG) of the refrigerant circuit (2) includes a second gas branch pipe (32) and a third gas branch pipe (33) branched from the main gas pipe (30), and the third gas branch pipe. And a first gas branch pipe (31) branched from (33). The first gas branch pipe (31) is at the second end of the first heat exchanger (11), and the second gas branch pipe (32) is at the second end of the second heat exchanger (12). A third gas branch pipe (33) is connected to the second end of the third heat exchanger (13).
[0033]
  The expansion mechanism (6) includes a first expansion mechanism (41) provided in the first liquid branch pipe (21), a second expansion mechanism (42) provided in the second liquid branch pipe (22), And a third expansion mechanism (43) provided in the third liquid branch pipe (23). As each expansion mechanism (41, 42, 43), it is possible to use a capillary tube or an expansion valve, but in carrying out the present invention, the decompression of the refrigerant corresponding to various operating conditions. In order to adjust the degree, an expansion valve whose opening degree can be adjusted such as an electronic expansion valve may be used.
[0034]
  In the first embodiment, a plurality of solenoid valves (open / close valves) (51, 52, 53) are provided as the switching means (8). Specifically, the first solenoid valve (first solenoid valve) is connected between the connection point of the second liquid branch pipe (22) with the first liquid branch pipe (21) and the connection point of the third liquid branch pipe (23). 1 on-off valve) (51) is provided. Further, between the second expansion mechanism (42) and the second heat exchanger (12) in the second liquid branch pipe (22), and between the third expansion mechanism (43) and the second heat exchanger (12) in the third liquid branch pipe (23). A second solenoid valve (second on-off valve) (52) is provided in a bypass passage (24) connected between the three heat exchangers (13). Further, a third solenoid valve (third on-off valve) is connected between the connection point of the third gas branch pipe (33) with the second gas branch pipe (32) and the connection point of the first gas branch pipe (31). ) (53) is provided.
[0035]
  The refrigerant circuit (2) is provided with switching means (8) composed of these solenoid valves (51, 52, 53), so that each heat exchanger (11, 12, The refrigerant flow in 13) can be switched between series and parallel. Further, the switching means (8) makes the flow direction of the refrigerant reversible in both the serial flow and the parallel flow. As for the serial flow, the refrigerant flows through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12) in this order, the second heat exchanger (12), The three heat exchangers (13) and the first heat exchanger (11) are configured so as to flow in series.
[0036]
      -Driving action-
  Next, the operation of the air conditioner will be described.
[0037]
  First, during cooling operation, the four-way selector valve (4) is set to the first communication state indicated by the solid line, the first solenoid valve (51) and the third solenoid valve (53) are opened, and the second solenoid valve is opened. Control to close (52) is performed. When the compressor (3) is started in this state, the refrigerant discharged from the compressor (3) flows into the outdoor heat exchanger (5) through the four-way switching valve (4), and the outdoor heat exchanger In (5), heat is exchanged with outdoor air to condense. The liquid refrigerant flowing out of the outdoor heat exchanger (5) flows into the indoor side through the main liquid pipe (20) and branches into the liquid branch pipes (21, 22, 23).
[0038]
  The liquid refrigerant is decompressed and expanded in the expansion mechanism (41, 42, 43) of each liquid branch pipe (21, 22, 23), and flows in parallel to each indoor heat exchanger (11, 12, 13). Here, the indoor air passing through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) and the refrigerant exchange heat to evaporate the refrigerant, The room air is sequentially cooled efficiently and returned to the room. Thereafter, the refrigerant passes through the first gas branch pipe (31), the second gas branch pipe (32), and the third gas branch pipe (33), and merges in the main gas pipe (30), and the four-way switching valve (4). Through the compressor (3). As the refrigerant repeats circulation as described above, the room is cooled.
[0039]
  Next, during the dehumidifying operation, the four-way selector valve (4) is set to the first communication state indicated by the solid line, and the first solenoid valve (51), the second solenoid valve (52), and the third solenoid valve ( Control to close all 53). When the compressor (3) is started in this state, the refrigerant discharged from the compressor (3) flows into the outdoor heat exchanger (5) through the four-way switching valve (4) as in the cooling operation. In the outdoor heat exchanger (5), heat is exchanged with outdoor air to condense. The liquid refrigerant flowing out of the outdoor heat exchanger (5) passes through the main liquid pipe (20), is reduced to an intermediate pressure by the first expansion mechanism (41), and flows into the first heat exchanger (11).
[0040]
  The refrigerant sequentially passes through the first heat exchanger (11) and the third heat exchanger (13) and evaporates at an intermediate pressure. Thereafter, the refrigerant is depressurized to a predetermined low pressure when passing through the third expansion mechanism (43) and the second expansion mechanism (42), and further evaporated in the second heat exchanger (12). The air flowing in the indoor heat exchanger (7) is precooled when the intermediate pressure refrigerant is heated to some extent in the first heat exchanger (11), and the low pressure refrigerant is heated in the second heat exchanger (12). In the third heat exchanger (13), after being dehumidified mainly, it is reheated by the refrigerant heated in the first heat exchanger and returned to the room. During this dehumidifying operation, the latent heat treatment is efficiently performed.
[0041]
  During heating operation, the four-way selector valve (4) is set to the second communication state indicated by a broken line, the first electromagnetic valve (51) and the third electromagnetic valve (53) are opened, and the second electromagnetic valve Control to close (52) is performed. When the compressor (3) is started in this state, the refrigerant discharged from the compressor (3) flows into the indoor side through the four-way switching valve (4), and each gas branch pipe (31, 32, 33) And flow into each indoor heat exchanger (11, 12, 13) in parallel. Here, the indoor air passing through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) and the refrigerant exchange heat to condense the refrigerant, The room air is sequentially heated efficiently and returned to the room.
[0042]
  Thereafter, when the refrigerant flows through the first liquid branch pipe (21), the second liquid branch pipe (22), and the third gas branch pipe (23), the refrigerant is decompressed and expanded by the expansion mechanisms (41, 42, 43). Further, after joining in the main liquid pipe (20), it flows into the outdoor heat exchanger (5). In the outdoor heat exchanger (5), the refrigerant evaporates by exchanging heat with the outdoor air and changes to a gas phase. Thereafter, the refrigerant passes through the four-way switching valve (4) and is sucked into the compressor (3) to complete one cycle of the heating operation. And the above heating cycle is repeated continuously and a room is heated.
[0043]
  In the first embodiment, during the heating operation, the circulation state of the refrigerant can be switched in series. At this time, the first solenoid valve (51) and the third solenoid valve (53) are closed, and the second solenoid valve (52) is opened. Therefore, the refrigerant flowing through the main gas pipe (30) from the compressor (3) passes through the second heat exchanger (12), the third heat exchanger (13), and the first heat exchanger (11) in this order. It condenses when flowing, and further expands by the first expansion mechanism (41) and then flows to the outdoor heat exchanger (5).
[0044]
      -Effect of Embodiment 1-
  According to the first embodiment, in the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) constituting the indoor heat exchanger (7), the refrigerant Therefore, it is possible to select a refrigerant flow with high operating efficiency even during the dehumidifying operation, the cooling operation, and the heating operation. As a result, it is possible to avoid the conventional problem that efficiency is reduced during cooling operation or heating operation even if efficiency is high during dehumidification operation, and it is possible to increase the total operation efficiency as the air conditioner (1). .
[0045]
  In particular, the serial flow in which the refrigerant flows through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12) in order during the dehumidifying operation, and the reciprocal operation during the cooling operation and the heating operation are reversed. The parallel flow in the direction can be selected, and the serial flow in the direction opposite to that in the dehumidifying operation can be selected during the heating operation, so that a decrease in efficiency during each operation can be effectively prevented. As a result, the total operating efficiency of the air conditioner can be reliably increased.
[0046]
  Furthermore, in the first embodiment, since the above-described effect can be realized only by using a plurality of solenoid valves (51, 52, 53), it is possible to prevent an increase in the cost of the apparatus.
[0047]
Second Embodiment of the Invention
  As shown in FIG. 2, the second embodiment of the present invention has a first heat exchanger (11), a second heat exchanger (12), and a third heat exchanger (13) on the indoor side in the refrigerant circuit (2). This is an example in which the connection mode is changed from that of the first embodiment. Hereinafter, a different part from Embodiment 1 is demonstrated.
[0048]
  In the second embodiment, the switching means (8) is configured to switch the refrigerant flow in each of the heat exchangers (11, 12, 13) constituting the indoor heat exchanger (7) to three types of serial flows. ing. More specifically, the switching means (8) includes a first series flow in which the refrigerant flows through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) in this order. , A second serial flow in which the refrigerant sequentially flows through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12), and the refrigerant is the third heat exchanger (13), The second heat exchanger (12) and the third heat exchanger (11) are configured to enable a third series flow in order.
[0049]
  For this reason, the liquid side pipe (PL) of the refrigerant circuit (2) is connected to the first end of the first heat exchanger (11) via the first expansion mechanism (41). The second end of the second heat exchanger (12) and the first end of the third heat exchanger (13) have a second expansion mechanism (42) and the expansion mechanism (42) for the refrigerant. A liquid side solenoid valve (first switching mechanism) (55) for bypassing is connected. In the second embodiment, the second expansion mechanism (42) and the liquid side solenoid valve (55) are connected in parallel. However, by using an expansion valve with an adjustable opening, such as an electronic expansion valve, The expansion valve may have the function of an on-off valve.
[0050]
  The second end of the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) and the main gas pipe (30) of the gas side pipe (PG) are: For example, the second four-way switching valve (56) in which the spool position is electrically switched to change the communication state (hereinafter, in this embodiment 2, the four-way switching valve (4) is the first four-way switching valve (4). Are connected to each other. In the second four-way selector valve (56), the third heat exchanger (13) communicates with the main gas pipe (30), and the first heat exchanger (11) and the second heat exchanger (12) are connected to each other. A first state of communication, a second heat exchanger (12) in communication with the main gas pipe (30), and a second state of communication between the first heat exchanger (11) and the third heat exchanger (13) The 2nd switching mechanism which switches between is comprised.
[0051]
  Specifically, the first gas branch pipe (31) is connected to the first port (P1) of the second four-way switching valve (56), and the second gas branch pipe (32) is connected to the second four-way switching valve ( 56) is connected to the second port (P2). The third gas branch pipe (33) is connected to the third port (P3) of the second four-way switching valve (56), and the main gas pipe (30) is the fourth port of the second four-way switching valve (56). Connected to port (P4). The second four-way selector valve (56) is in a first communication state in which the first port (P1) and the second port (P2) communicate with each other and the third port (P3) and the fourth port (P4) communicate with each other. (Solid state of solid line in FIG. 2), the second communication state in which the first port (P1) and the third port (P3) communicate, and the second port (P2) and the fourth port (P4) communicate ( It is configured to be able to switch between the broken line communication state in FIG.
[0052]
      -Driving action-
  Next, the operation in the air conditioner (1) of the second embodiment will be described.
[0053]
  First, during the cooling operation, the first four-way switching valve (4) is set to the first communication state indicated by the solid line, and the second four-way switching valve (56) is set to the first communication state. Further, control is performed to open the liquid side solenoid valve (55). When the compressor (3) is started in this state, the refrigerant discharged from the compressor (3) flows into the outdoor heat exchanger (5) through the four-way switching valve (4), and the outdoor heat exchanger In (5), heat is exchanged with outdoor air to condense.
[0054]
  The liquid refrigerant flowing out of the outdoor heat exchanger (5) flows into the indoor side through the main liquid pipe (20) and expands in the first expansion mechanism (41), and then the first heat exchanger (11) and the second heat exchanger (2). It flows through the heat exchanger (12) and the third heat exchanger (13) in this order. Here, the indoor air passing through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) and the refrigerant exchange heat to evaporate the refrigerant, The indoor air is efficiently cooled and returned to the room. Thereafter, the refrigerant is sucked into the compressor (3) from the third gas branch pipe (33) through the second four-way switching valve (56), the main gas pipe (30), and the first four-way switching valve (4). Then, one cycle of the cooling operation is completed. And the above cooling cycle is repeated continuously and efficient cooling operation is performed.
[0055]
  During the dehumidifying operation, the first four-way switching valve (4) is set to the first communication state indicated by the solid line, the second four-way switching valve (56) is set to the second communication state indicated by the broken line, and the liquid Control to close the side solenoid valve (55) is performed. When the compressor (3) is started in this state, the refrigerant discharged from the compressor (3) flows into the outdoor heat exchanger (5) through the four-way switching valve (4) as in the cooling operation. In the outdoor heat exchanger (5), heat is exchanged with outdoor air to condense. The liquid refrigerant flowing out of the outdoor heat exchanger (5) passes through the main liquid pipe (20), is decompressed and expanded to an intermediate pressure by the first expansion mechanism (41), and then flows into the first heat exchanger (11).
[0056]
  The liquid refrigerant sequentially passes through the first heat exchanger (11) and the third heat exchanger (13) and evaporates at an intermediate pressure. Thereafter, the refrigerant is depressurized to a predetermined low pressure by the second expansion mechanism (42) and evaporated by the second heat exchanger (12). The air flowing in the indoor heat exchanger (7) is first precooled in the first heat exchanger (11), mainly dehumidified in the second heat exchanger (12), and then in the third heat exchanger (13). It is reheated and returned to the room.
[0057]
  On the other hand, during heating operation, the four-way selector valve (4) is set to the second communication state indicated by the broken line, the second four-way selector valve (56) is set to the first communication state, and the solenoid valve (55) Control to release. When the compressor (3) is started in this state, the refrigerant discharged from the compressor (3) flows indoors through the first four-way switching valve (4) and the second four-way switching valve (56). , It condenses when it passes through the third heat exchanger (13), the second heat exchanger (12), and the first heat exchanger (11) in this order. At this time, the refrigerant is efficiently heated by exchanging heat with the indoor air flowing through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) in this order, and returned to the room. Is done. The liquid refrigerant flowing out of the first heat exchanger (11) is decompressed and expanded by the first expansion mechanism (41), and is evaporated by the outdoor heat exchanger (5). Thereafter, the refrigerant is sucked into the compressor (3) via the first four-way switching valve (4), and the above circulation operation is repeated.
[0058]
      -Effect of Embodiment 2-
  According to the second embodiment, the first serial flow in which the refrigerant sequentially flows through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13), and the refrigerant are the first A second series flow that flows through the heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12) in order, and the refrigerant is the third heat exchanger (13) and the second heat exchanger. (12) Since the third series flow that flows through the first heat exchanger (11) can be switched in sequence, an efficient refrigerant flow can be selected for each of the cooling operation, the dehumidifying operation, and the heating operation. And the total operating efficiency of the air conditioner can be increased.
[0059]
  Further, since only the liquid side solenoid valve (55) and the second four-way switching valve (56) are used to switch the refrigerant flow, a significant cost increase of the device (1) can be suppressed.
[0060]
Embodiment 3 of the Invention
  As shown in FIG. 3, the third embodiment of the present invention uses a plurality of on-off valves in place of the second four-way switching valve (56) of the second embodiment, thereby providing the second four-way switching valve (56). The same function is realized.
[0061]
  Specifically, the main gas pipe (30) is connected to the first heat exchanger (11) through the first gas branch pipe (31) and to the second heat exchanger (through the second gas branch pipe (32). 12) and via a third gas branch pipe (33) to the third heat exchanger (13). The first gas branch pipe (31) is located closer to the third heat exchanger (13) than the connection point between the second gas branch pipe (32) and the third gas branch pipe (33). Branching from 33).
[0062]
  The first gas branch pipe (31) is provided with a gas-side first electromagnetic valve (57), and is connected to the third gas branch pipe (33). The second gas branch pipe (32) is provided with a gas-side second electromagnetic valve (58) and is connected to the third gas branch pipe (33). The third gas branch pipe (33) includes a connection point between the third gas branch pipe (33) and the second gas branch pipe (32), a third gas branch pipe (33), and a first gas branch pipe ( A gas-side third solenoid valve (59) is provided between the connection point to 31). The first gas branch pipe (31) and the second gas branch pipe (32) are disposed between the first heat exchanger (11) and the gas side first electromagnetic valve (57) in the first gas branch pipe (31), The second heat exchanger (12) and the gas side second electromagnetic valve (58) in the second gas branch pipe (32) are connected via a gas side fourth electromagnetic valve (60).
[0063]
  In this embodiment, during the cooling operation, the four-way switching valve (4) is set to the first communication state, the gas side first solenoid valve (57) and the gas side second solenoid valve (58) are closed, The gas side third solenoid valve (59) and the gas side fourth solenoid valve (60) are opened. By doing so, the refrigerant flows in order through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) in the same manner as in the second embodiment, thereby efficiently cooling the indoor air. Is done.
[0064]
  During the dehumidifying operation, the gas side first solenoid valve (57), the gas side second solenoid valve (58) are opened, and the gas side third solenoid valve (59) and the gas side fourth solenoid valve (60) are closed. The By doing so, the refrigerant flows in order through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12) in the same manner as in the second embodiment, and the indoor air is efficiently dehumidified. Is done.
[0065]
  During heating operation, the gas side first solenoid valve (57), the gas side second solenoid valve (58) are closed, and the gas side third solenoid valve (59) and the gas side fourth solenoid valve (60) are closed. Opened. By doing so, the refrigerant flows through the third heat exchanger (13), the second heat exchanger (12), and the first heat exchanger (11) in order as in the second embodiment, and the indoor air is efficiently heated. Is done.
[0066]
  In the third embodiment, the same refrigerant flow as in the second embodiment can be realized, so that it is possible to suppress a decrease in efficiency during each operation of cooling, dehumidification, and heating, and the total operation efficiency of the air conditioner (1) can be increased. . Further, since the switching means (8) is composed of a plurality of solenoid valves (55) (57 to 60), a significant cost increase of the apparatus can be suppressed.
[0067]
【The invention's effect】
  According to the first aspect of the present invention, in the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) constituting the indoor heat exchanger (7), By switching the flow direction and order of the refrigerant by the switching means (4) and (8), it becomes possible to select an efficient refrigerant flow even during the dehumidifying operation, the cooling operation, and the heating operation. Even if the efficiency is high during the dehumidifying operation, it is possible to avoid the conventional problem that the efficiency decreases during the cooling operation or the heating operation, and it is possible to increase the total operation efficiency of the air conditioner (1).
[0068]
  Also,Claims 1 to 3In the first to third heat exchangers (11) to (13), the refrigerant flows in series or in parallel in accordance with the operating state, so that the air flows appropriately. The total operating efficiency of the harmony device (1) can be reliably increased. In particular,Claim 3According to the invention, during the dehumidifying operation, a state in which the refrigerant flows through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12) in order (in series) is selected, and cooling is performed. By selecting a state in which the refrigerant flows in parallel through the heat exchangers (11, 12, 13) during operation or heating operation, the effect can be ensured.
[0069]
  Also,Claim 4According to the invention described in the above, the configuration of the refrigerant circuit is specified, and the refrigerant flow with high processing efficiency during the dehumidifying operation and the refrigerant flow with high efficiency during the cooling operation and heating operation can be selected. The total operating efficiency of the device (1) can be reliably increased. Further, the above effect can be realized only by using a plurality of on-off valves (51, 52, 53), and the cost of the device (1) can be suppressed.
[0070]
  Also,Claims 5 and 6According to the invention described in the above, the state in which the refrigerant flows in series in the first heat exchanger (11), the second heat exchanger (12) and the third heat exchanger (13) is an operating state from among three types. By appropriately selecting according to the above, the total operation efficiency as the air conditioner (1) can be reliably increased. In particular,Claim 6According to the invention, the refrigerant flows through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) in order during the cooling operation, and the refrigerant is the first during the dehumidifying operation. A state in which the heat exchanger (11), the third heat exchanger (13), and the third heat exchanger (13) flow in that order, and the refrigerant flows during the heating operation in the third heat exchanger (13) and the second heat exchanger ( 12) By selecting the state in which the first heat exchanger (11) sequentially flows, the effect can be ensured.
[0071]
  Also,Claims 7 to 9According to the invention described in the above, the second switching mechanism including the four-way switching valve (56) and the plurality of on-off valves (57-60) and the first switching mechanism (55) are appropriately operated,Claim 6By realizing the three types of refrigerant flow of the invention, efficient operation is possible in each of the cooling operation, the dehumidifying operation, and the heating operation, and the total operation efficiency as the air conditioner (1) is increased. It is done. Also especiallyClaims 8 and 9According to this invention, since the above-described effect can be realized only by using the four-way switching valve (56) and the plurality of on-off valves (57-60), the cost of the apparatus can be suppressed.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 2 of the present invention.
FIG. 3 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 3 of the present invention.
[Explanation of symbols]
(1) Air conditioner
(2) Refrigerant circuit
(3) Compressor
(5) Outdoor heat exchanger
(6) Expansion mechanism
(7) Indoor heat exchanger
(8) Switching means
(11) First heat exchanger
(12) Second heat exchanger
(13) Third heat exchanger
(20) Main liquid pipe
(21) First liquid branch pipe
(22) Second liquid branch pipe
(23) Third liquid branch pipe
(24) Bypass passage
(30) Main gas pipe
(31) First gas branch pipe
(32) Second gas branch pipe
(33) Third gas branch pipe
(41) First expansion mechanism
(42) Second expansion mechanism
(43) Third expansion mechanism
(51) First on-off valve
(52) Second on-off valve
(53) Third on-off valve
(55) Liquid side solenoid valve (open / close valve, first switching mechanism)
(56) Second four-way switching valve (second switching mechanism)
(57-59) Gas side solenoid valve (open / close valve, second switching mechanism)
(PL) Liquid side piping
(PG) Gas side piping

Claims

A refrigerant circuit (2) in which a compressor (3), an outdoor heat exchanger (5), an expansion mechanism (6), and an indoor heat exchanger (7) are connected in order, and the indoor heat exchanger (7) is an air An air conditioner comprising a first heat exchanger (11), a second heat exchanger (12) and a third heat exchanger (13) arranged in order from the upstream side to the downstream side of the flow,
Switching means (4) (8) for switching the flow of refrigerant in each heat exchanger (11, 12, 13) constituting the indoor heat exchanger (7) ,
The switching means (4) and (8) are configured to switch the refrigerant flow in each heat exchanger (11, 12, 13) constituting the indoor heat exchanger (7) in series and in parallel. Air conditioner.

The switching means (4) and (8) switch the refrigerant flow in each heat exchanger (11, 12, 13) constituting the indoor heat exchanger (7) in series and in parallel, and at least one of the series and parallel 2. The air conditioner according to claim 1, wherein the air conditioner is configured to allow a reversible refrigerant flow .

The switching means (4) and (8) include a serial flow in which the refrigerant flows in order through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12), and a reversible parallel flow. The air conditioner according to claim 2, wherein the air conditioner is configured to enable the air conditioning.

The refrigerant circulation direction in the refrigerant circuit (2) is configured reversibly,
The liquid side pipe (PL) of the refrigerant circuit (2) includes a first liquid branch pipe (21) and a second liquid branch pipe (22) branched from the main liquid pipe (20), and the second liquid branch pipe (22 ), A first liquid branch pipe (21) is provided at the first end of the first heat exchanger (11), and a second liquid branch pipe (22) is provided. The third liquid branch pipe (23) is connected to the first end of the third heat exchanger (13) at the first end of the second heat exchanger (12),
The gas side pipe (PG) of the refrigerant circuit (2) includes a second gas branch pipe (32) and a third gas branch pipe (33) branched from the main gas pipe (30), and the third gas branch pipe (33 ) And a first gas branch pipe (31) at the second end of the first heat exchanger (11) and a second gas branch pipe (32). A third gas branch pipe (33) is connected to the second end of the third heat exchanger (13) at the second end of the second heat exchanger (12),
The expansion mechanism (6) includes a first expansion mechanism (41) provided in the first liquid branch pipe (21), a second expansion mechanism (42) provided in the second liquid branch pipe (22), and a third A third expansion mechanism (43) provided in the liquid branch pipe (23),
A first on-off valve (51) is provided between a connection point of the second liquid branch pipe (22) with the first liquid branch pipe (21) and a connection point of the third liquid branch pipe (23);
Between the second expansion mechanism (42) and the second heat exchanger (12) in the second liquid branch pipe (22), and between the third expansion mechanism (43) and the third heat in the third liquid branch pipe (23). A bypass passage (24) is connected to the exchanger (13) and a second on-off valve (52) is provided in the bypass passage (24).
A third on-off valve (53) is provided between the connection point of the third gas branch pipe (33) with the second gas branch pipe (32) and the connection point of the first gas branch pipe (31).
The air conditioner according to claim 3, wherein the first on-off valve (51), the second on-off valve (52), and the third on-off valve (53) constitute switching means (8) .

A refrigerant circuit (2) in which a compressor (3), an outdoor heat exchanger (5), an expansion mechanism (6), and an indoor heat exchanger (7) are connected in order, and the indoor heat exchanger (7) is an air An air conditioner comprising a first heat exchanger (11), a second heat exchanger (12) and a third heat exchanger (13) arranged in order from the upstream side to the downstream side of the flow,
Switching means (4) (8) for switching the flow of refrigerant in each heat exchanger (11, 12, 13) constituting the indoor heat exchanger (7),
The switching means (4) and (8) are configured to switch the refrigerant flow in each heat exchanger (11, 12, 13) constituting the indoor heat exchanger (7) into three types of serial flows. An air conditioner characterized by .

The switching means (4) and (8) include a first serial flow in which the refrigerant flows in order through the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13), and the refrigerant A second series flow that flows in order through the first heat exchanger (11), the third heat exchanger (13), and the second heat exchanger (12), and the refrigerant is the third heat exchanger (13) and the second heat. 6. The air conditioner according to claim 5 , wherein the air conditioner is configured to enable a third serial flow that sequentially flows through the exchanger (12) and the first heat exchanger (11) .

The refrigerant circulation direction in the refrigerant circuit (2) is configured reversibly,
The liquid side pipe (PL) of the refrigerant circuit (2) is connected to the first end of the first heat exchanger (11) via the first expansion mechanism (41),
A second expansion mechanism (42) and a refrigerant can bypass the expansion mechanism (42) at the first end of the second heat exchanger (12) and the first end of the third heat exchanger (13). Connected to the first switching mechanism (55),
The second end of the first heat exchanger (11), the second heat exchanger (12), and the third heat exchanger (13) is connected to the third heat exchanger (13) of the gas side pipe (PG). The first state where the main heat pipe (30) communicates with the first heat exchanger (11) and the second heat exchanger (12), and the second heat exchanger (12) is connected to the gas side pipe (PG The second switching mechanism (56) (57 to 59) that switches between the second state in which the first heat exchanger (11) and the third heat exchanger (13) communicate with each other. )
The air conditioner according to claim 6, wherein the first switching mechanism (55) and the second switching mechanism (56) (57 to 59) constitute switching means (8) .

The air conditioner according to claim 7, wherein the second switching mechanism is constituted by a four-way switching valve (56) .

The air conditioner according to claim 7, wherein the second switching mechanism is constituted by a plurality of on-off valves (57 to 59) .