JP2005009725A

JP2005009725A - Air conditioner and control method of air conditioner

Info

Publication number: JP2005009725A
Application number: JP2003172813A
Authority: JP
Inventors: Kazunobu Okawa; 和伸大川; Ryota Hirata; 亮太平田
Original assignee: Sanyo Electric Co Ltd; Sanyo Commercial Service Co Ltd
Current assignee: Sanyo Electric Co Ltd; Sanyo Commercial Service Co Ltd
Priority date: 2003-06-18
Filing date: 2003-06-18
Publication date: 2005-01-13
Anticipated expiration: 2023-06-18
Also published as: JP4086719B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner and a control method of the air conditioner capable of avoiding discharging refrigerant pressure of a compressor from rising to a pressure causing stop of the compressor and securing air conditioning properties. <P>SOLUTION: This air conditioner is structured by an outdoor unit 1 having outdoor heat exchangers 4a, 4b and indoor units 2a, 2b having indoor heat exchangers 6a, 6b connected with a pipe 10 for connecting the units and the indoor units 2a, 2b are structured to enable cooling operation or a heating operation. The air conditioner has the control unit 40 for making the outdoor heat exchanger 4a functioning as a condenser to be in a rest state and making the outdoor heat exchanger 4b in a rest state to function as a condenser while the outdoor heat exchanger 4a is functioning as a condenser and making the outdoor heat exchanger 4a in a rest state while the second outdoor heat exchangers 4a and 4b are functioning as condensers at the time that the outdoor heat exchanger 4b in the rest state is made to function as a condenser. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、複数台の室外熱交換器を有する室外ユニットを備えた空気調和装置及び空気調和装置の制御方法に関する。
【０００２】
【従来の技術】
一般に、圧縮機及び並列接続された複数台の室外熱交換器を有する室外ユニットと、室内熱交換器を有する複数台の室内ユニットとがユニット間配管で接続され、前記室内ユニットを冷房運転或いは暖房運転を行えるように構成された空気調和装置が知られている（例えば、特許文献１参照。）。
【０００３】
そして、室内ユニット側の空調負荷に応じて室外熱交換器の運転台数を制御する熱交換器の容量制御を行っている。この熱交換器の容量制御において、複数台の室外熱交換器の内、凝縮器として機能している第１の室外熱交換器を休止状態にさせ、且つ、休止状態である第２の室外熱交換器を凝縮器として機能させるように切替制御するものが知られている。
【０００４】
【特許文献１】
特許第２７６５９７０号公報
【０００５】
【発明が解決しようとする課題】
しかしながら、複数台の室外熱交換器の内、凝縮器として機能している第１の室外熱交換器を休止状態にさせ、且つ、休止状態である第２の室外熱交換器を凝縮器として機能させる切替制御をダイレクトに行った場合、冷媒の流れが急激に変化するため、圧縮機の吐出冷媒圧力が、全ての圧縮機を停止させる制御を行う圧縮機停止の圧力（例えば、２．８ＭＰａ）にまで上昇することがあるという問題がある。
【０００６】
このように、圧縮機の吐出冷媒圧力が圧縮機停止の圧力以上となった場合、圧縮機を保護するために、全ての圧縮機を所定時間（例えば、３分間）停止させる制御を行っているが、この全ての圧縮機を停止させている所定時間内は、空調運転ができなくなってしまい、空調性が低いものとなってしまうという問題がある。更に、所定時間経過後、圧縮機の運転が再開されても、再び、冷媒回路における最適な熱バランスを実現するまでに時間がかかってしまい、空調性が低いものとなってしまうという問題がある。
【０００７】
本発明の目的は、上述の事情を考慮してなされたものであり、休止状態の室外熱交換器を凝縮器として機能させ、且つ、凝縮器として機能している室外熱交換器を休止状態にさせる際に、圧縮機の吐出冷媒圧力が圧縮機停止の圧力にまで上昇するのを回避し、空調性を確保することができる空気調和装置及び空気調和装置の制御方法を提供することにある。
【０００８】
【課題を解決するための手段】
請求項１に記載の発明は、圧縮機及び並列接続された複数台の室外熱交換器を有する室外ユニットと、室内熱交換器を有する複数台の室内ユニットとがユニット間配管で接続され、前記室内ユニットを冷房運転或いは暖房運転を行えるように構成された空気調和装置において、前記複数台の室外熱交換器の内、凝縮器として機能している第１の室外熱交換器を休止状態にさせ、且つ、休止状態である第２の室外熱交換器を凝縮器として機能させる際に、前記第１の室外熱交換器が凝縮器として機能している状態で、休止状態である前記第２の室外熱交換器を凝縮器として機能させる第１の制御手段と、前記第１及び前記第２の室外熱交換器が凝縮器として機能している状態で、前記第１の室外熱交換器を休止状態にする第２の制御手段とを備えたことを特徴とするものである。
【０００９】
請求項２に記載の発明は、圧縮機及び並列接続された複数台の室外熱交換器を有する室外ユニットと、室内熱交換器を有する複数台の室内ユニットとがユニット間配管で接続され、前記室内ユニットを冷房運転或いは暖房運転を行えるように構成された空気調和装置において、前記複数台の室外熱交換器の内、凝縮器として機能している第１の室外熱交換器を休止状態にさせ、且つ、前記第１の室外熱交換器よりも熱交換容量が小さく休止状態である第２の室外熱交換器を凝縮器として機能させる際に、前記第１の室外熱交換器が凝縮器として機能している状態で、休止状態である前記第２の室外熱交換器を凝縮器として機能させる第１の制御手段と、前記第１及び前記第２の室外熱交換器が凝縮器として機能している状態で、前記第１の室外熱交換器を休止状態にする第２の制御手段とを備えたことを特徴とするものである。
【００１０】
請求項３に記載の発明は、請求項１又は２に記載の発明において、前記室外ユニットと前記複数台の室内ユニットとは、高圧ガス管、低圧ガス管及び液管を有するユニット間配管で接続され、室内ユニット毎に冷房運転或いは暖房運転を行えるように構成されることを特徴とするものである。
【００１１】
請求項４に記載の発明は、圧縮機及び並列接続された複数台の室外熱交換器を有する室外ユニットと、室内熱交換器を有する複数台の室内ユニットとがユニット間配管で接続され、前記室内ユニットを冷房運転或いは暖房運転を行えるように構成された空気調和装置の制御方法において、前記複数台の室外熱交換器の内、凝縮器として機能している第１の室外熱交換器を休止状態にさせ、且つ、休止状態である第２の室外熱交換器を凝縮器として機能させる際に、前記第１の室外熱交換器が凝縮器として機能している状態で、休止状態である前記第２の室外熱交換器を凝縮器として機能させる第１の制御過程と、前記第１及び前記第２の室外熱交換器が凝縮器として機能している状態で、前記第１の室外熱交換器を休止状態にする第２の制御過程とを備えたことを特徴とするものである。
【００１２】
請求項５に記載の発明は、圧縮機及び並列接続された複数台の室外熱交換器を有する室外ユニットと、室内熱交換器を有する複数台の室内ユニットとがユニット間配管で接続され、前記室内ユニットを冷房運転或いは暖房運転を行えるように構成された空気調和装置の制御方法において、前記複数台の室外熱交換器の内、凝縮器として機能している第１の室外熱交換器を休止状態にさせ、且つ、前記第１の室外熱交換器よりも熱交換容量が小さく休止状態である第２の室外熱交換器を凝縮器として機能させる際に、前記第１の室外熱交換器が凝縮器として機能している状態で、休止状態である前記第２の室外熱交換器を凝縮器として機能させる第１の制御過程と、前記第１及び前記第２の室外熱交換器が凝縮器として機能している状態で、前記第１の室外熱交換器を休止状態にする第２の制御過程とを備えたことを特徴とするものである。
【００１３】
【発明の実施の形態】
以下、本発明の実施の形態を、図面に基づき説明する。
【００１４】
図１は、本発明に係る空気調和装置の実施の形態を示す冷媒回路図等である。この空気調和装置５０は、室外ユニット１と複数台（本実施の形態では、２台）の室内ユニット２ａ，２ｂとを有して構成される。
【００１５】
室外ユニット１は、圧縮機３及び室外熱交換器４を備えている。圧縮機３は、図２に示すように、並列に接続された複数台（本実施の形態では、２台）の圧縮機（第１の圧縮機３ａ及び第２の圧縮機３ｂ）を備えている。本実施の形態では、圧縮機３は、第１の圧縮機３ａ及び第２の圧縮機３ｂから成るツインコンプレッサである。第１の圧縮機３ａと第２の圧縮機３ｂとは、最大容量（定格容量）が同じものである。
【００１６】
圧縮機３ａ，３ｂは、ガスエンジン（エンジン）３０を駆動源としている。第１の圧縮機３ａは、ガスエンジン３０に直結される。また、第２の圧縮機３ｂは、ガスエンジンにクラッチ３１を介して接離される。具体的に説明すると、ガスエンジン３０には、エンジンプーリ３２が接続され、第１の圧縮機３ａには、第１のプーリ３３が接続され、第２の圧縮機３ｂには、クラッチ３１を介して第２のプーリ３４が接続される。そして、エンジンプーリ３２、第１のプーリ３３及び第２のプーリ３４にはベルト３５が巻回されている。
【００１７】
第１の圧縮機３ａは、空気調和装置５０の運転動作時は、常時、ガスエンジン３０により駆動される。また、第２の圧縮機３ｂは、クラッチ３１がオン状態（入り状態）のときのみガスエンジン３０により駆動される。つまり、クラッチ３１がオン状態（入り状態）のとき、第１の圧縮機３ａ及び第２の圧縮機３ｂの２台がガスエンジン３０により駆動され、クラッチ３１がオフ状態（切り状態）のとき、第１の圧縮機３ａの１台のみがガスエンジン３０により駆動される。
【００１８】
室外熱交換器４には、図１に示すように、室外ファン５が隣接して配置されている。室外熱交換器４は、複数台（本実施の形態では、２台）の室外熱交換器４ａ，４ｂから成り、第１の室外熱交換器４ａと第２の室外熱交換器４ｂは、並列接続されている。本実施の形態では、第１の室外熱交換器４ａと第２の室外熱交換器４ｂとは、熱交換容量（定格熱交換容量）が異なる。つまり、第２の室外熱交換器４ｂは、第１の室外熱交換器４ａよりも熱交換容量（定格熱交換容量）が小さい。ここで、定格熱交換容量とは、熱交換器の最大熱交換容量のことである。
【００１９】
また、室内ユニット２ａ，２ｂは、室内熱交換器６ａ，６ｂ及び室内電子膨張弁１８ａ，１８ｂを備えている。室内熱交換器６ａ，６ｂのそれぞれには、室内ファン９ａ，９ｂのそれぞれが隣接して配置される。
【００２０】
そして、室外ユニット１と室内ユニット２ａ，２ｂとが、高圧ガス管１１、低圧ガス管１２及び液管１３を有するユニット間配管１０により接続されて、空気調和装置５０は、室内ユニット２ａ，２ｂを同時に冷房運転もしくは暖房運転可能とし、または、冷房運転と暖房運転とを混在して実施可能とする。つまり、室内ユニット２ａ，２ｂ毎に冷房運転或いは暖房運転を行えるように構成されている。
【００２１】
室外ユニット１では、室外熱交換器４の一端が、圧縮機３の冷媒吐出管７と冷媒吸込管８とに、択一に分岐して接続されている。
【００２２】
具体的には、第１の室外熱交換器４ａの一端が、圧縮機３の冷媒吐出管７に吐出側電磁弁２１ａを介して接続されるとともに、圧縮機３の冷媒吸込管８に吸込側電磁弁２２ａを介して接続される。また、第２の室外熱交換器４ｂの一端が、圧縮機３の冷媒吐出管７に吐出側電磁弁２１ｂを介して接続されるとともに、圧縮機３の冷媒吸込管８に吸込側電磁弁２２ｂを介して接続される。
【００２３】
そして、ユニット間配管１０の高圧ガス管１１は、圧縮機３の冷媒吐出管７に接続される。また、低圧ガス管１２は、圧縮機３の冷媒吸込管８に接続される。また、液管１３は、室外電子膨張弁２７ａ，２７ｂのそれぞれを介して室外熱交換器４ａ，４ｂのそれぞれの他端に接続される。
【００２４】
冷媒吸込管８には、アキュムレータ２４が配設され、冷媒吐出管７には、オイルセパレータ２５が配設されている。また、冷媒吐出管７と冷媒吸込管８とをバイパスする高低圧バイパス弁（電動弁）２３が設けられている。また、液管１３には、レシーバタンク２６が配設されている。
【００２５】
上記室内ユニット２ａの室内熱交換器６ａは、その一端が、高圧ガス分岐管１４ａを介して高圧ガス管１１に接続されるとともに、低圧ガス分岐管１５ａを介して低圧ガス管１２に接続される。また、室内ユニット２ｂの室内熱交換器６ｂは、その一端が、高圧ガス分岐管１４ｂを介して高圧ガス管１１に接続されるとともに、低圧ガス分岐管１５ｂを介して低圧ガス管１２に接続される。
【００２６】
高圧ガス分岐管１４ａ，１４ｂのそれぞれに、第１開閉弁（第１電磁開閉弁）１６ａ，１６ｂが配設される。また、低圧ガス分岐管１５ａ，１５ｂのそれぞれに、第２開閉弁（第２電磁開閉弁）１７ａ，１７ｂが配設される。
【００２７】
また、上記室内ユニット２ａ，２ｂのそれぞれの室内熱交換器６ａ，６ｂは、それらの他端が、室内電子膨張弁１８ａを配設した液分岐管１９ａ、室内電子膨張弁１８ｂを配設した液分岐管１９ｂを介して液管１３にそれぞれ接続される。
【００２８】
第１開閉弁１６ａ，１６ｂ、第２開閉弁１７ａ，１７ｂのそれぞれは、電磁弁ユニット２０ａ，２０ｂのそれぞれに格納されている。
【００２９】
圧縮機３の冷媒吐出管７には、圧縮機３の吐出冷媒圧力を検出するための圧力センサ４１が設けられている。
【００３０】
室外ユニット１には、空気調和装置５０全体を制御する制御装置４０が備えられている。
【００３１】
具体的には、制御装置４０は、圧縮機３の容量、室外電子膨張弁２７ａ，２７ｂの弁開度、吐出側電磁弁２１ａ，２１ｂの弁開閉、吸込側電磁弁２２ａ，２２ｂの弁開閉、室外ファン５の回転数、及び高低圧バイパス弁２３の開度等を制御する。また、制御装置４０は、室内電子膨張弁１８ａ，１８ｂの弁開度、電磁弁ユニット２０ａ，２０ｂの各電磁弁の弁開閉及び室内ファン９ａ，９ｂの回転数等を制御する。
【００３２】
図１中、室外電子膨張弁２７ａ，２７ｂおよび室内電子膨張弁１８ａ，１８ｂは、例えば不図示のステッピングモータによって弁開度が調整される。そして、例えば、ステッピングモータへ入力されるパルス（ステップ）が、例えば、２０ステップのときが全閉、４８０ステップのときが全開となるように設定されている。
【００３３】
また、制御装置４０は、冷媒吐出管７の吐出冷媒圧力を検出する（吐出冷媒圧力検出手段）。具体的には、制御装置４０は、圧力センサ４１により冷媒吐出管７の吐出冷媒圧力を検出している。
【００３４】
そして、制御装置４０は、この検出した吐出冷媒圧力が圧縮機３を停止させる圧力（圧縮機停止の圧力）以上となる場合、圧縮機３を所定時間（例えば、３分間）停止させる制御を行っている。つまり、冷媒吐出管７の吐出冷媒圧力が圧縮機停止の圧力以上となる状態のまま圧縮機３の運転を継続した場合、空気調和装置５０を構成する各種機器（特に、圧縮機３）が破損する恐れがあるためである。圧縮機停止の圧力は、例えば、２．８ＭＰａである。このように、吐出冷媒圧力が圧縮機停止の圧力以上となる場合、圧縮機３が所定時間に亘って停止するので、空気調和装置５０を構成する各種機器（特に、圧縮機３）が破損するのを回避することができる。
【００３５】
さて、全室内ユニット２ａ，２ｂを同時に冷房運転する場合、或いは例えば室内ユニット２ａを冷房運転し、室内ユニット２ｂを暖房運転する場合において、室内ユニット２ａ，２ｂ側の冷房負荷Ｑｃと暖房負荷Ｑｈとの差（Ｑｃ−Ｑｈ）が第１のしきい値を下回る場合、制御装置４０は、第１の室外熱交換器４ａを凝縮器に機能させ、且つ、第２の室外熱交換器４ｂを休止状態にする制御を行う。
【００３６】
そして、室内ユニット２ａ，２ｂ側の冷房負荷と暖房負荷との差が第１のしきい値よりも小さい第２のしきい値を下回る場合、制御装置４０は、凝縮器として機能している第１の室外熱交換器４ａを休止状態にさせ、且つ、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させる制御を行う。但し、差（Ｑｃ−Ｑｈ）は正の値、つまり、Ｑｃ＞Ｑｈであるものとする。尚、全室内ユニット２ａ，２ｂを同時に冷房運転する場合、暖房負荷Ｑｈは０である。
【００３７】
第１の室外熱交換器４ａを休止させる場合、制御装置４０は、室外電子膨張弁２７ａを略全閉（全閉を含む。）に制御するとともに、吐出側電磁弁２１ａ及び吸込側電磁弁２２ａを閉弁する制御を行う。また、第２の室外熱交換器４ｂを休止させる場合、制御装置４０は、室外電子膨張弁２７ｂを略全閉（全閉を含む。）に制御するとともに、吐出側電磁弁２１ｂ及び吸込側電磁弁２２ｂを閉弁する制御を行う。
【００３８】
ところで、上記空気調和装置５０の運転状態において、仮に、凝縮器として機能している第１の室外熱交換器４ａを休止状態にさせ、且つ、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させる切替制御をダイレクトに行うと、室外熱交換器４において冷媒の流れが急激に変化するため、圧縮機３の吐出冷媒圧力が上昇して圧縮機３の吐出冷媒圧力が圧縮機停止の圧力（例えば、２．８ＭＰａ）に至り、圧縮機３を所定時間（例えば、３分間）停止させる制御に移行してしまうことがある。
【００３９】
特に、第２の室外熱交換器４ｂは、第１の室外熱交換器４ａよりも熱交換容量が小さい、つまり、第２の室外熱交換器４ｂは、第１の室外熱交換器４ａよりも小型であるので、仮に、凝縮器として機能している第１の室外熱交換器４ａを休止状態にさせ、且つ、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させる切替制御をダイレクトに行うと、圧縮機３の吐出冷媒圧力が圧縮機停止の圧力（例えば、２．８ＭＰａ）に至り易い。
【００４０】
本実施の形態では、凝縮器として機能している第１の室外熱交換器４ａを休止状態にさせ、且つ、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させる際、圧縮機３の吐出冷媒圧力が圧縮機停止の圧力（例えば、２．８ＭＰａ）に至らないように、室外熱交換器４の冷媒の流れを制御するものである。
【００４１】
以下、制御装置４０の制御動作について図３の室外熱交換器４の動作状況を示す説明図を参照しながら具体的に説明する。
【００４２】
まず、室内ユニット２ａ，２ｂ側の冷房負荷Ｑｃと暖房負荷Ｑｈとの差（Ｑｃ−Ｑｈ）が、第１のしきい値を下回り、且つ、第１のしきい値よりも小さい第２のしきい値を上回る場合、制御装置４０（図１）は、第１の室外熱交換器４ａを凝縮器として機能させ、第２の室外熱交換器４ｂを休止状態にさせる制御を行う（ステップＳ１）。具体的には、第１の室外熱交換器４ａを凝縮器として機能させるために、制御装置４０は、吐出側電磁弁２１ａを開弁制御、吸込側電磁弁２２ａを閉弁制御し、室外電子膨張弁２７ａを略全開（全開を含む。）に制御する。更に、制御装置４０は、第２の室外熱交換器４ｂを休止状態にさせるために、吐出側電磁弁２１ｂを閉弁制御、吸込側電磁弁２２ｂを閉弁制御し、室外電子膨張弁２７ｂを略全閉（全閉を含む。）に制御する。ここで、本実施の形態では、室外熱交換器４は、第１の室外熱交換器４ａが１台と、第２の室外熱交換器４ｂが１台とで構成されているので、圧縮機３から吐出された冷媒は、室外熱交換器４の内、第１の室外熱交換器４ａにのみ流れる。
【００４３】
このステップＳ１における状態で、室内ユニット２ａ，２ｂ側の冷房負荷Ｑｃと暖房負荷Ｑｈとの差（Ｑｃ−Ｑｈ）が第２のしきい値を下回る場合、制御装置４０は、凝縮器として機能している第１の室外熱交換器４ａを休止状態にさせ、且つ、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させるに先立って、第１の室外熱交換器４ａが凝縮器として機能している状態で、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させる制御を行う（ステップＳ２）。
【００４４】
具体的には、制御装置４０は、第１の室外熱交換器４ａを凝縮器として機能させる状態を継続するために、制御装置４０は、吐出側電磁弁２１ａを開弁制御、吸込側電磁弁２２ａを閉弁制御し、室外電子膨張弁２７ａを略全開（全開を含む。）にする制御を継続しつつ、更に、第２の室外熱交換器４ｂを凝縮器として機能させるために、吐出側電磁弁２１ｂを開弁制御、吸込側電磁弁２２ｂを閉弁制御し、室外電子膨張弁２７ｂを略全開（全開を含む。）に制御する。このとき、圧縮機３は、空調負荷（冷房負荷Ｑｃと暖房負荷Ｑｈとの差）に応じた容量で運転されている。これによって、第１の室外熱交換器４ａ及び第２の室外熱交換器４ｂに冷媒が流れることになる。
【００４５】
このステップＳ２において、第１及び第２の室外熱交換器４ａ，４ｂを凝縮器として機能させる制御は、第２の室外熱交換器４ｂを凝縮器として機能させてから予め設定した時間（例えば、２０秒）に亘って行われる。
【００４６】
次いで、制御装置４０は、ステップＳ２において、予め設定した時間（例えば、２０秒）経過後、第１及び第２の室外熱交換器４ａ，４ｂを凝縮器として機能させている状態から、第１の室外熱交換器４ｂを休止状態にする制御を行う（ステップＳ３）。
【００４７】
具体的には、制御装置４０は、第１の室外熱交換器４ａを休止状態にするために、吐出側電磁弁２１ａ及び吸込側電磁弁２２ａを閉弁制御し、室外電子膨張弁２７ａを略全閉（全閉を含む。）にする制御を行う。
【００４８】
このように、第１の室外熱交換器４ａを休止状態にした直後、圧縮機３の吐出冷媒圧力は、第１の室外熱交換器４ａを休止状態にする直前よりも上昇することとなるが、圧縮機停止の圧力（例えば、２．８ＭＰａ）にまで上昇することはない。つまり、ステップＳ１からステップＳ２を経てステップＳ３に切り替えるようにしたことで、圧縮機３の吐出冷媒圧力が圧縮機停止の圧力（例えば、２．８ＭＰａ）にまで急激に上昇するのを回避することができる。
【００４９】
特に、第２の室外熱交換器４ｂは、第１の室外熱交換器４ａよりも熱交換容量が小さい、つまり、第２の室外熱交換器４ｂは、第１の室外熱交換器４ａよりも小型であるので、凝縮器として機能している第１の室外熱交換器４ａを休止状態にさせ、且つ、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させる際、圧縮機３の吐出冷媒圧力は、圧縮機停止の圧力にまで上昇するのをより効果的に回避することができる。
【００５０】
このように、圧縮機３の吐出冷媒圧力は、圧縮機停止の圧力にまで上昇することはないので、圧縮機３が停止する制御に移行することはない。従って、凝縮器として機能している第１の室外熱交換器４ａを休止状態にさせ、且つ、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させる制御を行った後に、速やかに冷媒の熱バランスを安定させることができるので、空調性を確保することができる。
【００５１】
さて、以下に本実施形態における空気調和装置５０の空調運転動作について詳細に説明する。
【００５２】
まず、全室内ユニット２ａ，２ｂを同時に冷房運転する場合は、高圧ガス管１１が休止状態におかれる。
【００５３】
この場合、制御装置４０は、吐出側電磁弁２１ａ，２１ｂを開くとともに吸込側電磁弁２２ａ，２２ｂを閉じ、且つ電磁弁ユニット２０ａ，２０ｂの第１開閉弁１６ａ，１６ｂを閉じるとともに、第２開閉弁１７ａ，１７ｂを開く。更に、制御装置４０は、室外電子膨張弁２７ａ，２７ｂを略全開（全開を含む）に制御するとともに、室内電子膨張弁１８ａ，１８ｂの開度を制御する。つまり、室外熱交換器４ａ，４ｂを凝縮器として機能させるとともに、室内熱交換器６ａ，６ｂを蒸発器として機能させている。
【００５４】
これにより、圧縮機３から吐出された冷媒は、冷媒吐出管７、オイルセパレータ２５、吐出側電磁弁２１ａ，２１ｂ、室外熱交換器４ａ，４ｂへと順次流れ、室外熱交換器４ａ，４ｂで凝縮液化する。凝縮液化した冷媒は、室外電子膨張弁２７ａ，２７ｂ及びレシーバタンク２６を通過し、液管１３と液分岐管１９ａ，１９ｂを経て各室ユニット２ａ，２ｂの室内電子膨張弁１８ａ，１８ｂに分配され、ここで減圧される。
【００５５】
しかる後、室内電子膨張弁１８ａ，１８ｂで減圧された冷媒は、各室内熱交換器６ａ，６ｂで蒸発気化した後、それぞれ第２開閉弁１７ａ，１７ｂを流れ、低圧ガス管１２、冷媒吸込管８、アキュムレータ２４を順次経て圧縮機３に吸入される。
【００５６】
このように、蒸発器として機能する各室内熱交換器６ａ，６ｂで全室内ユニット２ａ，２ｂが同時に冷房運転される。
【００５７】
また、全室内ユニット２ａ，２ｂを同時に暖房運転する場合は、低圧ガス管１２が休止状態におかれる。
【００５８】
この場合、制御装置４０は、吐出側電磁弁２１ａ，２１ｂを閉じるとともに、吸込側電磁弁２２ａ，２２ｂを開き、且つ電磁弁ユニット２０ａ，２０ｂの第１開閉弁１６ａ，１６ｂを開くとともに、第２開閉弁１７ａ，１７ｂを閉じる。更に、制御装置４０は、室内電子膨張弁１８ａ，１８ｂを略全開（全開を含む）に制御するとともに、室外電子膨張弁２７ａ，２７ｂの開度を制御する。つまり、室外熱交換器４ａ，４ｂを蒸発器として機能させるとともに、室内熱交換器６ａ，６ｂを凝縮器として機能させている。
【００５９】
これにより、圧縮機３から吐出された冷媒は、冷媒吐出管７、オイルセパレータ２５、高圧ガス管１１を順次経て高圧ガス分岐管１４ａ，１４ｂに分配された後、第１開閉弁１６ａ，１６ｂ、室内熱交換器６ａ，６ｂへと流れ、ここでそれぞれ凝縮液化する。
【００６０】
凝縮液化した冷媒は、液分岐管１９ａ，１９ｂを経て液管１３で合流される。
【００６１】
しかる後、液管１３の液冷媒は、レシーバタンク２６を通過し、各室外電子膨張弁２７ａ，２７ｂで減圧された後、各室外熱交換器４ａ，４ｂで蒸発気化する。この蒸発気化した冷媒は、吸込側電磁弁２２ａ，２２ｂ、冷媒吸込管８、アキュムレータ２４を順次経て圧縮機３に吸入される。このように凝縮器として機能する各室内熱交換器６ａ，６ｂで、全室内ユニット２ａ，２ｂが同時に暖房運転される。
【００６２】
次に、例えば室内ユニット２ａを冷房運転し、室内ユニット２ｂを暖房運転する場合は、ユニット間配管１０のうち、全ての冷媒管１１，１２，１３が使用される。まず、室内ユニット２ａ側の冷房負荷が室内ユニット２ｂ側の暖房負荷よりも大きい場合について説明する。
【００６３】
この場合、制御装置４０は、吐出側電磁弁２１ａ，２１ｂを開くとともに吸込側電磁弁２２ａ，２２ｂを閉じ、且つ、冷房運転する室内ユニット２ａの電磁弁ユニット２０ａにおける第１開閉弁１６ａを閉じるとともに、第２開閉弁１７ａを開き、且つ暖房運転する室内ユニット２ｂの電磁弁ユニット２０ｂにおける第１開閉弁１６ｂを開くとともに、第２開閉弁１７ｂとを閉じる。更に、制御装置４０は、室外電子膨張弁２７ａ，２７ｂ及び室内電子膨張弁１８ｂを略全開（全開を含む）に制御するとともに、室内電子膨張弁１８ａの開度を制御する。つまり、室外熱交換器４ａ，４ｂ及び室内熱交換器６ｂを凝縮器として機能させるとともに、室内熱交換器６ａを蒸発器として機能させている。
【００６４】
すると、圧縮機３から吐出され、冷媒吐出管７及びオイルセパレータ２５を通過した冷媒の一部が、吐出側電磁弁２１ａ，２１ｂを経て室外熱交換器４ａ，４ｂに流れるとともに、残りの冷媒が高圧ガス管１１を経て暖房運転する室内ユニット２ｂの電磁弁ユニット２０ｂにおける第１開閉弁１６ｂ、室内熱交換器６ｂへと流れる。これによって、冷媒が室外熱交換器４ａ，４ｂ及び室内熱交換器６ｂで凝縮液化される。
【００６５】
そして、室外熱交換器４ａ，４ｂ及び室内熱交換器６ｂで凝縮液化された冷媒は、液管１３を経て室内ユニット２ａの室内電子膨張弁１８ａで減圧された後、室内熱交換器６ａで蒸発気化される。しかる後、冷媒は、第２開閉弁１７ａを流れて低圧ガス管１２、冷媒吸込管８、アキュムレータ２４を順次経て圧縮機３に吸入される。このように、凝縮器として機能する室内熱交換器６ｂで室内ユニット２ｂが暖房運転され、蒸発器として機能する室内熱交換器６ａで室内ユニット２ａが冷房運転される。
【００６６】
次に、室内ユニット２ｂ側の暖房負荷が室内ユニット２ａ側の冷房負荷よりも大きい場合について説明する。
【００６７】
この場合、制御装置４０は、吐出側電磁弁２１ａ，２１ｂを閉じるとともに吸込側電磁弁２２ａ，２２ｂを開き、且つ冷房運転する室内ユニット２ａの電磁弁ユニット２０ａにおける第１開閉弁１６ａを閉じるとともに、第２開閉弁１７ａを開き、且つ暖房運転する室内ユニット２ｂの電磁弁ユニット２０ｂにおける第１開閉弁１６ｂを開くとともに、第２開閉弁１７ｂを閉じる。更に、制御装置４０は、室内電子膨張弁１８ｂを略全開（全開を含む）に制御するとともに、室外電子膨張弁２７ａ，２７ｂ及び室内電子膨張弁１８ａの開度を制御する。つまり、室内熱交換器６ｂを凝縮器として機能させるとともに、室外熱交換器４ａ，４ｂ及び室内熱交換器６ａを蒸発器として機能させている。
【００６８】
すると、圧縮機３から吐出された冷媒は、冷媒吐出管７、高圧ガス管１１を順次経て第１開閉弁１６ｂを通過して室内熱交換器６ｂで凝縮液化される。
【００６９】
そして、この液化された冷媒は、略全開された室内電子膨張弁１８ｂを経て液管１３に流れる。この液管中の液冷媒の一部が、室内電子膨張弁１８ａで減圧された後に室内熱交換器６ｂで、且つ、残りの液冷媒が室外電子膨張弁２７ａ，２７ｂで減圧された後に室外熱交換器４ａ，４ｂでそれぞれ蒸発気化され、冷媒吸込管８、アキュムレータ２４を順次経て圧縮機３に吸入される。このように、凝縮器として機能する室内熱交換器６ｂで室内ユニット２ｂが暖房運転され、蒸発器として機能する室内熱交換器６ａで室内ユニット２ａが冷房運転される。
【００７０】
以上の如く、冷房運転する室内ユニット２ａ側の冷房負荷が、暖房運転する室内ユニット２ｂ側の暖房負荷よりも大きいときは、室外熱交換器４ａ，４ｂを凝縮器として機能させる。一方、冷房する室内ユニット２ａ側の冷房負荷が、暖房する室内ユニット２ｂ側の暖房負荷よりも小さいときは、室外熱交換器４ａ，４ｂを蒸発器として機能させる。従って、任意の室内ユニット２ａ，２ｂを自由に冷暖房することができる。
【００７１】
更に、室内ユニット２ａ，２ｂの冷房負荷と暖房負荷とが同じ場合、制御装置４０は、第１の室外熱交換器４ａ及び第２の室外熱交換器４ｂを休止させる。つまり、制御装置４０は、室外電子膨張弁２７ａ及び２７ｂを略全閉（全閉を含む。）に制御するとともに、吐出側電磁弁２１ａ，２１ｂ及び吸込側電磁弁２２ａ、２２ｂを閉弁する制御を行う。
【００７２】
以上、本実施の形態によれば、複数台の室外熱交換器４ａ，４ｂの内、凝縮器として機能している第１の室外熱交換器４ａを休止状態にさせ、且つ、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させる際に、第１の室外熱交換器４ａが凝縮器として機能している状態で、休止状態である第２の室外熱交換器４ｂを凝縮器として機能させるようにしたことから、圧縮機３の吐出冷媒圧力が圧縮機停止の圧力に至るのを回避することができ、圧縮機３が停止することはないので、空調性を確保することができる。
【００７３】
特に、第２の室外熱交換器４ｂが、第１の室外熱交換器４ａよりも小さい場合、より効果的に圧縮機３の吐出冷媒圧力が圧縮機停止の圧力に至るのを回避することができる。
【００７４】
以上、本発明を上記実施の形態に基づいて説明したが、本発明はこれに限定されるものではない。
【００７５】
例えば、上記実施の形態では、冷媒吐出管に圧力センサを設け、吐出冷媒圧力を検出する場合について説明したが、冷媒吐出管に温度センサを設け、この温度センサによる温度検出結果に基づいて吐出冷媒圧力を算出するようにしてもよい。
【００７６】
また、上記実施の形態では、圧縮機が複数台の場合について説明したが、圧縮機が１台の場合であってもよい。
【００７７】
また、上記実施の形態では、圧縮機がエンジンとしてのガスエンジンにより駆動される場合について説明したが、これに限るものではなく、圧縮機が電動モータ（例えば、ブラシレスＤＣモータ）を内蔵し、このモータがインバータ装置等を介して電力供給されることで、圧縮機が駆動されるものでもよい。
【００７８】
また、上記実施の形態では、第２の室外熱交換器は第１の室外熱交換器よりも熱交換容量が小さい、つまり、第２の室外熱交換器は第１の室外熱交換器よりも小型である場合について説明したが、これに限るものではない。例えば、第２の室外熱交換器は第１の室外熱交換器よりも熱交換容量が大きい、つまり、第２の室外熱交換器は第１の室外熱交換器よりも大型である場合であってもよいし、第１の室外熱交換器及び第２の室外熱交換器の熱交換容量が同じ、つまり、第１の室外熱交換器及び第２の室外熱交換器が同型であってもよい。
【００７９】
そして、第１の室外熱交換器及び第２の室外熱交換器の熱交換容量が同じ、つまり、第１の室外熱交換器及び第２の室外熱交換器が同型である場合においては、休止状態の第２の室外熱交換器に冷媒が過剰に寝込んだとき、凝縮器として機能している第１の室外熱交換器を休止状態にさせ、且つ、休止状態である第２の室外熱交換器を凝縮器として機能させることで、冷媒のガス欠の防止を図ることができる。このようにガス欠防止制御を行う場合であっても、凝縮器として機能している第１の室外熱交換器を休止状態にさせ、且つ、休止状態である第２の室外熱交換器を凝縮器として機能させる際に、第１の室外熱交換器が凝縮器として機能している状態で、休止状態である第２の室外熱交換器を凝縮器として機能させるようにしたことから、圧縮機の吐出冷媒圧力が圧縮機停止の圧力に至るのを回避することができ、圧縮機が停止することはないので、空調性を確保することができる。
【００８０】
また、上記実施の形態では、複数台の室外熱交換器として、１台の第１の室外熱交換器と１台の第２の室外熱交換器から成る２台の室外熱交換器の場合について説明したが、これに限るものではなく、第１の室外熱交換器が複数台の場合であってもよいし、第２の室外熱交換器が複数台の場合であってもよい。また、第１、第２の室外熱交換器のほかに、これら第１、第２の室外熱交換器に並列に接続される他の室外熱交換器があってもよい。
【００８１】
【発明の効果】
本発明によれば、休止状態の室外熱交換器を凝縮器として機能させ、且つ、凝縮器として機能している室外熱交換器を休止状態にさせる際に、圧縮機の吐出冷媒圧力が圧縮機停止の圧力にまで上昇するのを回避し、空調性を確保することができる。
【図面の簡単な説明】
【図１】本発明による空気調和装置の一実施の形態を示す冷媒回路図等である。
【図２】圧縮機の駆動系を示すブロック図である。
【図３】室外熱交換器の動作状況を示す説明図である。
【符号の説明】
１室外ユニット
２ａ，２ｂ室内ユニット
３圧縮機
４室外熱交換器
４ａ第１の室外熱交換器
４ｂ第２の室外熱交換器
１０ユニット間配管
１１高圧ガス管
１２低圧ガス管
１３液管
３０ガスエンジン（エンジン）
４０制御装置（第１の制御手段、第２の制御手段）
５０空気調和装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner including an outdoor unit having a plurality of outdoor heat exchangers and a method for controlling the air conditioner.
[0002]
[Prior art]
In general, an outdoor unit having a compressor and a plurality of outdoor heat exchangers connected in parallel and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, and the indoor unit is cooled or heated. An air conditioner configured to be able to operate is known (for example, see Patent Document 1).
[0003]
And the capacity control of the heat exchanger which controls the number of operating outdoor heat exchangers according to the air conditioning load on the indoor unit side is performed. In the capacity control of the heat exchanger, the first outdoor heat exchanger functioning as a condenser among the plurality of outdoor heat exchangers is put into a dormant state, and the second outdoor heat that is in a dormant state There is known a switch that performs switching control so that the exchanger functions as a condenser.
[0004]
[Patent Document 1]
Japanese Patent No. 2765970
[0005]
[Problems to be solved by the invention]
However, among the plurality of outdoor heat exchangers, the first outdoor heat exchanger functioning as a condenser is put into a dormant state, and the second outdoor heat exchanger in a dormant state functions as a condenser. When the switching control is performed directly, the flow of the refrigerant changes abruptly. Therefore, the discharge refrigerant pressure of the compressor is a compressor stop pressure (for example, 2.8 MPa) that controls to stop all the compressors. There is a problem that it may rise to.
[0006]
Thus, when the discharge refrigerant pressure of the compressor becomes equal to or higher than the compressor stop pressure, control is performed to stop all the compressors for a predetermined time (for example, 3 minutes) in order to protect the compressors. However, there is a problem that the air-conditioning operation cannot be performed within a predetermined time during which all the compressors are stopped, and the air-conditioning performance is low. Furthermore, even if the operation of the compressor is resumed after a predetermined time has passed, there is a problem that it takes time to realize the optimum heat balance in the refrigerant circuit again, resulting in poor air conditioning. .
[0007]
The object of the present invention has been made in consideration of the above-mentioned circumstances. The outdoor heat exchanger in a dormant state functions as a condenser, and the outdoor heat exchanger that functions as a condenser is put in a dormant state. It is an object of the present invention to provide an air conditioner and a control method for the air conditioner that can prevent the discharge refrigerant pressure of the compressor from rising to the compressor stop pressure and ensure air conditioning.
[0008]
[Means for Solving the Problems]
In the first aspect of the present invention, an outdoor unit having a compressor and a plurality of outdoor heat exchangers connected in parallel and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, In the air conditioner configured to allow the indoor unit to perform a cooling operation or a heating operation, the first outdoor heat exchanger functioning as a condenser among the plurality of outdoor heat exchangers is put into a dormant state. And when making the 2nd outdoor heat exchanger which is a dormant state function as a condenser, in the state where the 1st outdoor heat exchanger is functioning as a condenser, the 2nd above-mentioned dormant state The first control means for causing the outdoor heat exchanger to function as a condenser, and the first outdoor heat exchanger being suspended in a state where the first and second outdoor heat exchangers are functioning as condensers. A second control means for setting the state It is characterized in that the.
[0009]
In the invention according to claim 2, an outdoor unit having a compressor and a plurality of outdoor heat exchangers connected in parallel, and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, In the air conditioner configured to allow the indoor unit to perform a cooling operation or a heating operation, the first outdoor heat exchanger functioning as a condenser among the plurality of outdoor heat exchangers is put into a dormant state. And when making the 2nd outdoor heat exchanger which has a heat exchange capacity smaller than the 1st outdoor heat exchanger and is a dormant state function as a condenser, the 1st outdoor heat exchanger serves as a condenser. In a functioning state, the first control means for functioning the second outdoor heat exchanger in a dormant state as a condenser, and the first and second outdoor heat exchangers function as a condenser. The first chamber It is characterized in that a second control means for the heat exchanger into hibernation.
[0010]
The invention according to claim 3 is the invention according to claim 1 or 2, wherein the outdoor unit and the plurality of indoor units are connected by inter-unit piping having a high pressure gas pipe, a low pressure gas pipe and a liquid pipe. In addition, each indoor unit is configured to perform a cooling operation or a heating operation.
[0011]
In the invention according to claim 4, an outdoor unit having a compressor and a plurality of outdoor heat exchangers connected in parallel, and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, In the control method of the air conditioner configured to perform the cooling operation or the heating operation of the indoor unit, the first outdoor heat exchanger functioning as a condenser is paused among the plurality of outdoor heat exchangers. When the second outdoor heat exchanger that is in a resting state and functioning as a condenser functions as a condenser, the first outdoor heat exchanger that is functioning as a condenser is in the resting state A first control process for causing the second outdoor heat exchanger to function as a condenser; and the first outdoor heat exchanger in a state in which the first and second outdoor heat exchangers function as a condenser. Second control to put the instrument into a dormant state It is characterized in that a degree.
[0012]
In the invention according to claim 5, an outdoor unit having a compressor and a plurality of outdoor heat exchangers connected in parallel, and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, In the control method of the air conditioner configured to perform the cooling operation or the heating operation of the indoor unit, the first outdoor heat exchanger functioning as a condenser is paused among the plurality of outdoor heat exchangers. When the first outdoor heat exchanger is caused to function as a condenser and the second outdoor heat exchanger having a heat exchange capacity smaller than that of the first outdoor heat exchanger and being in a dormant state is used as the condenser A first control process in which the second outdoor heat exchanger in a resting state functions as a condenser while functioning as a condenser, and the first and second outdoor heat exchangers are condensers. Functioning as before It is characterized in that a second control process of the first outdoor heat exchanger dormant.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a refrigerant circuit diagram showing an embodiment of an air-conditioning apparatus according to the present invention. The air conditioner 50 includes an outdoor unit 1 and a plurality of (in the present embodiment, two) indoor units 2a and 2b.
[0015]
The outdoor unit 1 includes a compressor 3 and an outdoor heat exchanger 4. As illustrated in FIG. 2, the compressor 3 includes a plurality of (two in the present embodiment) compressors (first compressor 3 a and second compressor 3 b) connected in parallel. Yes. In the present embodiment, the compressor 3 is a twin compressor including a first compressor 3a and a second compressor 3b. The first compressor 3a and the second compressor 3b have the same maximum capacity (rated capacity).
[0016]
The compressors 3a and 3b use a gas engine (engine) 30 as a drive source. The first compressor 3 a is directly connected to the gas engine 30. The second compressor 3b is connected to and separated from the gas engine via the clutch 31. Specifically, an engine pulley 32 is connected to the gas engine 30, a first pulley 33 is connected to the first compressor 3a, and a clutch 31 is connected to the second compressor 3b. Thus, the second pulley 34 is connected. A belt 35 is wound around the engine pulley 32, the first pulley 33 and the second pulley 34.
[0017]
The first compressor 3 a is always driven by the gas engine 30 during the operation of the air conditioner 50. The second compressor 3b is driven by the gas engine 30 only when the clutch 31 is in an on state (an engaged state). That is, when the clutch 31 is in the on state (on state), the two units, the first compressor 3a and the second compressor 3b, are driven by the gas engine 30, and when the clutch 31 is in the off state (disengaged state), Only one of the first compressors 3 a is driven by the gas engine 30.
[0018]
As shown in FIG. 1, an outdoor fan 5 is disposed adjacent to the outdoor heat exchanger 4. The outdoor heat exchanger 4 is composed of a plurality of (in this embodiment, two) outdoor heat exchangers 4a and 4b, and the first outdoor heat exchanger 4a and the second outdoor heat exchanger 4b are arranged in parallel. It is connected. In the present embodiment, the first outdoor heat exchanger 4a and the second outdoor heat exchanger 4b have different heat exchange capacities (rated heat exchange capacities). That is, the second outdoor heat exchanger 4b has a smaller heat exchange capacity (rated heat exchange capacity) than the first outdoor heat exchanger 4a. Here, the rated heat exchange capacity is the maximum heat exchange capacity of the heat exchanger.
[0019]
The indoor units 2a and 2b include indoor heat exchangers 6a and 6b and indoor electronic expansion valves 18a and 18b. The indoor fans 9a and 9b are respectively disposed adjacent to the indoor heat exchangers 6a and 6b.
[0020]
And the outdoor unit 1 and indoor unit 2a, 2b are connected by the inter-unit piping 10 which has the high pressure gas pipe 11, the low pressure gas pipe 12, and the liquid pipe 13, and the air conditioning apparatus 50 is the indoor unit 2a, 2b. At the same time, the cooling operation or the heating operation can be performed, or the cooling operation and the heating operation can be performed together. That is, the indoor unit 2a, 2b is configured to perform a cooling operation or a heating operation.
[0021]
In the outdoor unit 1, one end of the outdoor heat exchanger 4 is alternatively branched and connected to the refrigerant discharge pipe 7 and the refrigerant suction pipe 8 of the compressor 3.
[0022]
Specifically, one end of the first outdoor heat exchanger 4a is connected to the refrigerant discharge pipe 7 of the compressor 3 via the discharge-side electromagnetic valve 21a, and is connected to the refrigerant suction pipe 8 of the compressor 3 on the suction side. It is connected via a solenoid valve 22a. One end of the second outdoor heat exchanger 4b is connected to the refrigerant discharge pipe 7 of the compressor 3 via the discharge side electromagnetic valve 21b, and the suction side electromagnetic valve 22b is connected to the refrigerant suction pipe 8 of the compressor 3. Connected through.
[0023]
The high-pressure gas pipe 11 of the inter-unit pipe 10 is connected to the refrigerant discharge pipe 7 of the compressor 3. The low-pressure gas pipe 12 is connected to the refrigerant suction pipe 8 of the compressor 3. The liquid pipe 13 is connected to the other end of each of the outdoor heat exchangers 4a and 4b via each of the outdoor electronic expansion valves 27a and 27b.
[0024]
The refrigerant suction pipe 8 is provided with an accumulator 24, and the refrigerant discharge pipe 7 is provided with an oil separator 25. Further, a high / low pressure bypass valve (electric valve) 23 that bypasses the refrigerant discharge pipe 7 and the refrigerant suction pipe 8 is provided. A receiver tank 26 is disposed in the liquid pipe 13.
[0025]
One end of the indoor heat exchanger 6a of the indoor unit 2a is connected to the high pressure gas pipe 11 via the high pressure gas branch pipe 14a and to the low pressure gas pipe 12 via the low pressure gas branch pipe 15a. . One end of the indoor heat exchanger 6b of the indoor unit 2b is connected to the high pressure gas pipe 11 via the high pressure gas branch pipe 14b and to the low pressure gas pipe 12 via the low pressure gas branch pipe 15b. The
[0026]
First on-off valves (first electromagnetic on-off valves) 16a and 16b are disposed in the high-pressure gas branch pipes 14a and 14b, respectively. In addition, second on-off valves (second electromagnetic on-off valves) 17a and 17b are disposed in the low-pressure gas branch pipes 15a and 15b, respectively.
[0027]
The indoor heat exchangers 6a and 6b of the indoor units 2a and 2b have a liquid branch pipe 19a provided with the indoor electronic expansion valve 18a and a liquid provided with the indoor electronic expansion valve 18b at the other end. Each is connected to the liquid pipe 13 via the branch pipe 19b.
[0028]
The first on-off valves 16a and 16b and the second on-off valves 17a and 17b are respectively stored in the electromagnetic valve units 20a and 20b.
[0029]
The refrigerant discharge pipe 7 of the compressor 3 is provided with a pressure sensor 41 for detecting the discharge refrigerant pressure of the compressor 3.
[0030]
The outdoor unit 1 is provided with a control device 40 that controls the entire air conditioner 50.
[0031]
Specifically, the control device 40 includes the capacity of the compressor 3, the valve opening degree of the outdoor electronic expansion valves 27a and 27b, the valve opening and closing of the discharge side electromagnetic valves 21a and 21b, the valve opening and closing of the suction side electromagnetic valves 22a and 22b, The rotational speed of the outdoor fan 5 and the opening degree of the high / low pressure bypass valve 23 are controlled. Further, the control device 40 controls the valve opening degree of the indoor electronic expansion valves 18a, 18b, the opening / closing of each electromagnetic valve of the electromagnetic valve units 20a, 20b, the rotational speed of the indoor fans 9a, 9b, and the like.
[0032]
In FIG. 1, the opening degree of the outdoor electronic expansion valves 27a and 27b and the indoor electronic expansion valves 18a and 18b are adjusted by, for example, a stepping motor (not shown). For example, the pulse (step) input to the stepping motor is set to be fully closed when, for example, 20 steps are fully open when it is 480 steps.
[0033]
Further, the control device 40 detects the discharge refrigerant pressure of the refrigerant discharge pipe 7 (discharge refrigerant pressure detection means). Specifically, the control device 40 detects the discharge refrigerant pressure of the refrigerant discharge pipe 7 by the pressure sensor 41.
[0034]
Then, when the detected discharge refrigerant pressure becomes equal to or higher than the pressure at which the compressor 3 is stopped (pressure at which the compressor is stopped), the control device 40 performs control to stop the compressor 3 for a predetermined time (for example, 3 minutes). ing. That is, when the operation of the compressor 3 is continued in a state where the refrigerant pressure discharged from the refrigerant discharge pipe 7 is equal to or higher than the pressure at which the compressor is stopped, various devices (particularly, the compressor 3) constituting the air conditioner 50 are damaged. Because there is a risk of doing. The pressure for stopping the compressor is, for example, 2.8 MPa. Thus, when the discharge refrigerant pressure is equal to or higher than the compressor stop pressure, the compressor 3 is stopped for a predetermined time, so that various devices (particularly, the compressor 3) constituting the air conditioner 50 are damaged. Can be avoided.
[0035]
Now, when all the indoor units 2a and 2b are operated for cooling at the same time, or when the indoor unit 2a is operated for cooling and the indoor unit 2b is operated for heating, for example, the cooling loads Qc and heating loads Qh on the indoor units 2a and 2b side When the difference (Qc−Qh) is less than the first threshold value, the control device 40 causes the first outdoor heat exchanger 4a to function as a condenser and deactivates the second outdoor heat exchanger 4b. Control to put in the state.
[0036]
When the difference between the cooling load and the heating load on the indoor unit 2a, 2b side is lower than the second threshold value which is smaller than the first threshold value, the control device 40 functions as a condenser. Control is performed so that the first outdoor heat exchanger 4a is in a dormant state and the second outdoor heat exchanger 4b in a dormant state functions as a condenser. However, the difference (Qc−Qh) is a positive value, that is, Qc> Qh. In addition, when all the indoor units 2a and 2b are air-cooled at the same time, the heating load Qh is zero.
[0037]
When the first outdoor heat exchanger 4a is suspended, the control device 40 controls the outdoor electronic expansion valve 27a to be substantially fully closed (including fully closed), and the discharge side solenoid valve 21a and the suction side solenoid valve 22a. Control to close the valve. When the second outdoor heat exchanger 4b is suspended, the control device 40 controls the outdoor electronic expansion valve 27b to be substantially fully closed (including fully closed), as well as the discharge-side solenoid valve 21b and the suction-side solenoid. Control is performed to close the valve 22b.
[0038]
By the way, in the operation state of the air conditioner 50, the first outdoor heat exchanger 4a functioning as a condenser is temporarily put into a dormant state, and the second outdoor heat exchanger 4b that is in a dormant state is put into the dormant state. If the switching control to function as a condenser is performed directly, the refrigerant flow in the outdoor heat exchanger 4 changes abruptly, so that the discharge refrigerant pressure of the compressor 3 rises and the discharge refrigerant pressure of the compressor 3 changes to the compressor. A stop pressure (for example, 2.8 MPa) may be reached, and control may be shifted to stop the compressor 3 for a predetermined time (for example, 3 minutes).
[0039]
In particular, the second outdoor heat exchanger 4b has a smaller heat exchange capacity than the first outdoor heat exchanger 4a, that is, the second outdoor heat exchanger 4b is smaller than the first outdoor heat exchanger 4a. Since it is small in size, it is assumed that the first outdoor heat exchanger 4a functioning as a condenser is put into a dormant state, and the second outdoor heat exchanger 4b that is in a dormant state functions as a condenser. If it is directly performed, the discharge refrigerant pressure of the compressor 3 tends to reach the compressor stop pressure (for example, 2.8 MPa).
[0040]
In the present embodiment, when the first outdoor heat exchanger 4a functioning as a condenser is put into a dormant state and the second outdoor heat exchanger 4b that is in a dormant state is made to function as a condenser, compression is performed. The refrigerant flow in the outdoor heat exchanger 4 is controlled so that the refrigerant discharge pressure of the machine 3 does not reach the compressor stop pressure (for example, 2.8 MPa).
[0041]
Hereinafter, the control operation of the control device 40 will be specifically described with reference to an explanatory diagram showing an operation state of the outdoor heat exchanger 4 in FIG. 3.
[0042]
First, a second process is performed in which the difference (Qc−Qh) between the cooling load Qc and the heating load Qh on the indoor units 2a and 2b side is less than the first threshold value and smaller than the first threshold value. When the threshold value is exceeded, the control device 40 (FIG. 1) controls the first outdoor heat exchanger 4a to function as a condenser and causes the second outdoor heat exchanger 4b to be in a dormant state (step S1). . Specifically, in order to cause the first outdoor heat exchanger 4a to function as a condenser, the control device 40 performs valve opening control on the discharge side electromagnetic valve 21a and valve closing control on the suction side electromagnetic valve 22a. The expansion valve 27a is controlled to be substantially fully open (including fully open). Further, the control device 40 controls the discharge side electromagnetic valve 21b to close, the suction side electromagnetic valve 22b to close, and sets the outdoor electronic expansion valve 27b to make the second outdoor heat exchanger 4b inactive. It is controlled to be substantially fully closed (including fully closed). Here, in the present embodiment, the outdoor heat exchanger 4 is composed of one first outdoor heat exchanger 4a and one second outdoor heat exchanger 4b. The refrigerant discharged from 3 flows only to the first outdoor heat exchanger 4a in the outdoor heat exchanger 4.
[0043]
When the difference (Qc−Qh) between the cooling load Qc and the heating load Qh on the indoor units 2a and 2b side is lower than the second threshold value in the state in step S1, the control device 40 functions as a condenser. The first outdoor heat exchanger 4a is condensed before the first outdoor heat exchanger 4a is in a quiescent state and the second outdoor heat exchanger 4b in a quiescent state is made to function as a condenser. Control is performed so that the second outdoor heat exchanger 4b in the resting state functions as a condenser while functioning as a condenser (step S2).
[0044]
Specifically, in order to continue the state in which the control device 40 functions the first outdoor heat exchanger 4a as a condenser, the control device 40 controls the opening of the discharge-side electromagnetic valve 21a and the suction-side electromagnetic valve. In order to make the second outdoor heat exchanger 4b function as a condenser while continuing the control to close the valve 22a and to make the outdoor electronic expansion valve 27a substantially fully open (including fully open), the discharge side The solenoid valve 21b is controlled to open, the suction side solenoid valve 22b is controlled to close, and the outdoor electronic expansion valve 27b is controlled to be substantially fully open (including fully open). At this time, the compressor 3 is operated with a capacity corresponding to the air conditioning load (difference between the cooling load Qc and the heating load Qh). As a result, the refrigerant flows through the first outdoor heat exchanger 4a and the second outdoor heat exchanger 4b.
[0045]
In this step S2, the control for causing the first and second outdoor heat exchangers 4a and 4b to function as a condenser is a time set in advance after the second outdoor heat exchanger 4b functions as a condenser (for example, 20 seconds).
[0046]
Next, in step S2, the control device 40 starts from the state in which the first and second outdoor heat exchangers 4a and 4b function as condensers after a preset time (for example, 20 seconds) has elapsed. The outdoor heat exchanger 4b is controlled to be in a dormant state (step S3).
[0047]
Specifically, the control device 40 controls the discharge-side solenoid valve 21a and the suction-side solenoid valve 22a to be closed in order to put the first outdoor heat exchanger 4a into a dormant state, and the outdoor electronic expansion valve 27a is substantially omitted. Control to make it fully closed (including fully closed).
[0048]
As described above, immediately after the first outdoor heat exchanger 4a is put into a dormant state, the discharge refrigerant pressure of the compressor 3 rises more than immediately before the first outdoor heat exchanger 4a is put into a dormant state. The pressure does not increase to the compressor stop pressure (for example, 2.8 MPa). That is, by switching from step S1 to step S3 via step S2, it is possible to avoid a sudden increase in the discharge refrigerant pressure of the compressor 3 to a compressor stop pressure (for example, 2.8 MPa). Can do.
[0049]
In particular, the second outdoor heat exchanger 4b has a smaller heat exchange capacity than the first outdoor heat exchanger 4a, that is, the second outdoor heat exchanger 4b is smaller than the first outdoor heat exchanger 4a. When the first outdoor heat exchanger 4a functioning as a condenser is in a dormant state and the second outdoor heat exchanger 4b in a dormant state is functioning as a condenser because of its small size, the compressor It is possible to more effectively avoid the discharge refrigerant pressure No. 3 from increasing to the compressor stop pressure.
[0050]
Thus, since the discharge refrigerant | coolant pressure of the compressor 3 does not raise to the pressure of a compressor stop, it does not transfer to the control which the compressor 3 stops. Therefore, immediately after performing the control which makes the 1st outdoor heat exchanger 4a which functions as a condenser a dormant state, and makes the 2nd outdoor heat exchanger 4b which is a dormant state function as a condenser, immediately In addition, since the heat balance of the refrigerant can be stabilized, air conditioning can be ensured.
[0051]
Now, the air conditioning operation of the air conditioner 50 in the present embodiment will be described in detail below.
[0052]
First, in the case where all the indoor units 2a and 2b are cooled at the same time, the high-pressure gas pipe 11 is put into a resting state.
[0053]
In this case, the control device 40 opens the discharge-side solenoid valves 21a and 21b, closes the suction-side solenoid valves 22a and 22b, closes the first on-off valves 16a and 16b of the solenoid valve units 20a and 20b, and opens the second on-off valve. The valves 17a and 17b are opened. Further, the control device 40 controls the outdoor electronic expansion valves 27a and 27b to be fully open (including fully open), and controls the opening degree of the indoor electronic expansion valves 18a and 18b. That is, the outdoor heat exchangers 4a and 4b function as a condenser, and the indoor heat exchangers 6a and 6b function as an evaporator.
[0054]
As a result, the refrigerant discharged from the compressor 3 sequentially flows to the refrigerant discharge pipe 7, the oil separator 25, the discharge-side electromagnetic valves 21a and 21b, and the outdoor heat exchangers 4a and 4b, and in the outdoor heat exchangers 4a and 4b. Condensed liquid. The condensed and liquefied refrigerant passes through the outdoor electronic expansion valves 27a and 27b and the receiver tank 26, and is distributed to the indoor electronic expansion valves 18a and 18b of the chamber units 2a and 2b via the liquid pipe 13 and the liquid branch pipes 19a and 19b. , Where the pressure is reduced.
[0055]
Thereafter, the refrigerant depressurized by the indoor electronic expansion valves 18a and 18b evaporates and evaporates in the indoor heat exchangers 6a and 6b, and then flows through the second on-off valves 17a and 17b, respectively. The low-pressure gas pipe 12 and the refrigerant suction pipe 8. The air is sucked into the compressor 3 through the accumulator 24 sequentially.
[0056]
In this way, all the indoor units 2a and 2b are simultaneously cooled in the indoor heat exchangers 6a and 6b functioning as evaporators.
[0057]
Moreover, when heating all the indoor units 2a and 2b simultaneously, the low-pressure gas pipe 12 is put into a resting state.
[0058]
In this case, the control device 40 closes the discharge-side solenoid valves 21a and 21b, opens the suction-side solenoid valves 22a and 22b, and opens the first on-off valves 16a and 16b of the solenoid valve units 20a and 20b. The on-off valves 17a and 17b are closed. Further, the control device 40 controls the indoor electronic expansion valves 18a and 18b to be fully open (including fully open) and the opening degree of the outdoor electronic expansion valves 27a and 27b. That is, the outdoor heat exchangers 4a and 4b function as an evaporator, and the indoor heat exchangers 6a and 6b function as a condenser.
[0059]
Thereby, the refrigerant discharged from the compressor 3 is distributed to the high-pressure gas branch pipes 14a and 14b through the refrigerant discharge pipe 7, the oil separator 25, and the high-pressure gas pipe 11 in order, and then the first on-off valves 16a and 16b, It flows to the indoor heat exchangers 6a and 6b, where it condensates.
[0060]
The condensed and liquefied refrigerant is merged in the liquid pipe 13 through the liquid branch pipes 19a and 19b.
[0061]
Thereafter, the liquid refrigerant in the liquid pipe 13 passes through the receiver tank 26, is decompressed by the outdoor electronic expansion valves 27a and 27b, and then evaporates and evaporates in the outdoor heat exchangers 4a and 4b. The evaporated and evaporated refrigerant is sucked into the compressor 3 through the suction side solenoid valves 22a and 22b, the refrigerant suction pipe 8, and the accumulator 24 in order. Thus, in each indoor heat exchanger 6a, 6b functioning as a condenser, all the indoor units 2a, 2b are simultaneously heated.
[0062]
Next, for example, when the indoor unit 2 a is cooled and the indoor unit 2 b is heated, all the refrigerant pipes 11, 12, and 13 of the inter-unit pipe 10 are used. First, the case where the cooling load on the indoor unit 2a side is larger than the heating load on the indoor unit 2b side will be described.
[0063]
In this case, the control device 40 opens the discharge-side electromagnetic valves 21a and 21b, closes the suction-side electromagnetic valves 22a and 22b, and closes the first on-off valve 16a in the electromagnetic valve unit 20a of the indoor unit 2a that performs the cooling operation. The second on-off valve 17a is opened, and the first on-off valve 16b in the electromagnetic valve unit 20b of the indoor unit 2b to be heated is opened, and the second on-off valve 17b is closed. Further, the control device 40 controls the outdoor electronic expansion valves 27a and 27b and the indoor electronic expansion valve 18b to be substantially fully open (including fully open), and also controls the opening degree of the indoor electronic expansion valve 18a. That is, the outdoor heat exchangers 4a and 4b and the indoor heat exchanger 6b function as a condenser, and the indoor heat exchanger 6a functions as an evaporator.
[0064]
Then, a part of the refrigerant discharged from the compressor 3 and passing through the refrigerant discharge pipe 7 and the oil separator 25 flows to the outdoor heat exchangers 4a and 4b via the discharge-side electromagnetic valves 21a and 21b, and the remaining refrigerant flows. It flows to the first on-off valve 16b and the indoor heat exchanger 6b in the electromagnetic valve unit 20b of the indoor unit 2b that performs heating operation via the high-pressure gas pipe 11. As a result, the refrigerant is condensed and liquefied in the outdoor heat exchangers 4a and 4b and the indoor heat exchanger 6b.
[0065]
The refrigerant condensed and liquefied in the outdoor heat exchangers 4a and 4b and the indoor heat exchanger 6b is reduced in pressure in the indoor electronic expansion valve 18a of the indoor unit 2a via the liquid pipe 13, and then evaporated in the indoor heat exchanger 6a. Vaporized. Thereafter, the refrigerant flows through the second on-off valve 17 a and is sucked into the compressor 3 through the low-pressure gas pipe 12, the refrigerant suction pipe 8, and the accumulator 24 in order. Thus, the indoor unit 2b is heated by the indoor heat exchanger 6b that functions as a condenser, and the indoor unit 2a is cooled by the indoor heat exchanger 6a that functions as an evaporator.
[0066]
Next, a case where the heating load on the indoor unit 2b side is larger than the cooling load on the indoor unit 2a side will be described.
[0067]
In this case, the control device 40 closes the discharge-side electromagnetic valves 21a and 21b, opens the suction-side electromagnetic valves 22a and 22b, closes the first on-off valve 16a in the electromagnetic valve unit 20a of the indoor unit 2a that performs the cooling operation, The second on-off valve 17a is opened, the first on-off valve 16b in the electromagnetic valve unit 20b of the indoor unit 2b to be heated is opened, and the second on-off valve 17b is closed. Further, the control device 40 controls the indoor electronic expansion valve 18b to be fully open (including fully open) and also controls the opening degrees of the outdoor electronic expansion valves 27a and 27b and the indoor electronic expansion valve 18a. That is, the indoor heat exchanger 6b functions as a condenser, and the outdoor heat exchangers 4a and 4b and the indoor heat exchanger 6a function as an evaporator.
[0068]
Then, the refrigerant discharged from the compressor 3 sequentially passes through the refrigerant discharge pipe 7 and the high-pressure gas pipe 11, passes through the first on-off valve 16b, and is condensed and liquefied in the indoor heat exchanger 6b.
[0069]
The liquefied refrigerant flows into the liquid pipe 13 through the indoor electronic expansion valve 18b that is substantially fully opened. A part of the liquid refrigerant in the liquid pipe is decompressed by the indoor electronic expansion valve 18a and then the indoor heat exchanger 6b, and the remaining liquid refrigerant is decompressed by the outdoor electronic expansion valves 27a and 27b and the outdoor heat. The gas is evaporated and vaporized by the exchangers 4a and 4b, and sucked into the compressor 3 through the refrigerant suction pipe 8 and the accumulator 24 in order. Thus, the indoor unit 2b is heated by the indoor heat exchanger 6b that functions as a condenser, and the indoor unit 2a is cooled by the indoor heat exchanger 6a that functions as an evaporator.
[0070]
As described above, when the cooling load on the indoor unit 2a side in the cooling operation is larger than the heating load on the indoor unit 2b side in the heating operation, the outdoor heat exchangers 4a and 4b are caused to function as condensers. On the other hand, when the cooling load on the indoor unit 2a side to be cooled is smaller than the heating load on the indoor unit 2b side to be heated, the outdoor heat exchangers 4a and 4b are caused to function as evaporators. Therefore, any indoor units 2a and 2b can be freely cooled and heated.
[0071]
Furthermore, when the cooling load and the heating load of the indoor units 2a and 2b are the same, the control device 40 pauses the first outdoor heat exchanger 4a and the second outdoor heat exchanger 4b. That is, the control device 40 controls the outdoor electronic expansion valves 27a and 27b to be substantially fully closed (including fully closed), and closes the discharge side electromagnetic valves 21a and 21b and the suction side electromagnetic valves 22a and 22b. I do.
[0072]
As described above, according to the present embodiment, among the plurality of outdoor heat exchangers 4a and 4b, the first outdoor heat exchanger 4a functioning as a condenser is put into a dormant state and is in a dormant state. When the second outdoor heat exchanger 4b functions as a condenser, the second outdoor heat exchanger 4b that is in a resting state is condensed while the first outdoor heat exchanger 4a functions as a condenser. Since the compressor 3 functions as a compressor, the discharge refrigerant pressure of the compressor 3 can be prevented from reaching the compressor stop pressure, and the compressor 3 never stops. Can do.
[0073]
In particular, when the second outdoor heat exchanger 4b is smaller than the first outdoor heat exchanger 4a, the discharge refrigerant pressure of the compressor 3 can be more effectively avoided from reaching the compressor stop pressure. it can.
[0074]
As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this.
[0075]
For example, in the above embodiment, the case where the pressure sensor is provided in the refrigerant discharge pipe and the discharge refrigerant pressure is detected has been described, but the temperature sensor is provided in the refrigerant discharge pipe, and the discharge refrigerant is based on the temperature detection result by the temperature sensor The pressure may be calculated.
[0076]
Moreover, although the said embodiment demonstrated the case where there were two or more compressors, the case where there is one compressor may be sufficient.
[0077]
Moreover, although the said embodiment demonstrated the case where a compressor was driven by the gas engine as an engine, it is not restricted to this, A compressor incorporates an electric motor (for example, brushless DC motor), and this The compressor may be driven by supplying electric power to the motor via an inverter device or the like.
[0078]
In the above embodiment, the second outdoor heat exchanger has a smaller heat exchange capacity than the first outdoor heat exchanger, that is, the second outdoor heat exchanger is smaller than the first outdoor heat exchanger. Although the case where it was small was demonstrated, it does not restrict to this. For example, the second outdoor heat exchanger has a larger heat exchange capacity than the first outdoor heat exchanger, that is, the second outdoor heat exchanger is larger than the first outdoor heat exchanger. The heat exchange capacities of the first outdoor heat exchanger and the second outdoor heat exchanger may be the same, that is, the first outdoor heat exchanger and the second outdoor heat exchanger may be the same type. Good.
[0079]
Then, when the heat exchange capacities of the first outdoor heat exchanger and the second outdoor heat exchanger are the same, that is, when the first outdoor heat exchanger and the second outdoor heat exchanger are the same type, When the refrigerant has excessively stagnated in the second outdoor heat exchanger in the state, the first outdoor heat exchanger functioning as a condenser is put into a dormant state, and the second outdoor heat exchange in a dormant state By causing the condenser to function as a condenser, it is possible to prevent the refrigerant from running out of gas. Even in the case of performing the gas shortage prevention control in this way, the first outdoor heat exchanger functioning as a condenser is put into a dormant state, and the second outdoor heat exchanger that is in a dormant state is condensed. When the first outdoor heat exchanger is functioning as a condenser when the first outdoor heat exchanger functions as a condenser, the second outdoor heat exchanger in a dormant state is allowed to function as a condenser. Therefore, it is possible to prevent the discharged refrigerant pressure from reaching the pressure at which the compressor stops and the compressor does not stop, so that air conditioning can be ensured.
[0080]
Moreover, in the said embodiment, about the case of the two outdoor heat exchangers which consist of one 1st outdoor heat exchanger and one 2nd outdoor heat exchanger as several outdoor heat exchangers. Although it demonstrated, it is not restricted to this, The case where two or more 1st outdoor heat exchangers may be sufficient, and the case where two or more 2nd outdoor heat exchangers are sufficient may be sufficient. In addition to the first and second outdoor heat exchangers, there may be other outdoor heat exchangers connected in parallel to the first and second outdoor heat exchangers.
[0081]
【The invention's effect】
According to the present invention, when the outdoor heat exchanger in a dormant state functions as a condenser and the outdoor heat exchanger that functions as a condenser is set in a dormant state, the refrigerant discharge pressure of the compressor is reduced. It is possible to avoid the rise to the stop pressure and to ensure air conditioning.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram showing an embodiment of an air conditioner according to the present invention.
FIG. 2 is a block diagram showing a drive system of the compressor.
FIG. 3 is an explanatory diagram showing an operation state of the outdoor heat exchanger.
[Explanation of symbols]
1 outdoor unit
2a, 2b Indoor unit
3 Compressor
4 outdoor heat exchangers
4a First outdoor heat exchanger
4b Second outdoor heat exchanger
10 Inter-unit piping
11 High-pressure gas pipe
12 Low pressure gas pipe
13 Liquid pipe
30 Gas engine (engine)
40 control device (first control means, second control means)
50 Air conditioner

Claims

An outdoor unit having a compressor and a plurality of outdoor heat exchangers connected in parallel and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, and the indoor unit is cooled or heated. In an air conditioner configured to be able to
Of the plurality of outdoor heat exchangers, the first outdoor heat exchanger functioning as a condenser is put into a dormant state, and the second outdoor heat exchanger in a dormant state is made to function as a condenser In the state where the first outdoor heat exchanger is functioning as a condenser, the first control means for functioning the second outdoor heat exchanger in a dormant state as a condenser,
And a second control means for putting the first outdoor heat exchanger into a dormant state in a state where the first and second outdoor heat exchangers function as a condenser. Air conditioner.

An outdoor unit having a compressor and a plurality of outdoor heat exchangers connected in parallel and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, and the indoor unit is cooled or heated. In an air conditioner configured to be able to
Among the plurality of outdoor heat exchangers, the first outdoor heat exchanger functioning as a condenser is put into a dormant state, and the heat exchange capacity is smaller than the first outdoor heat exchanger and the dormant state. When the second outdoor heat exchanger as a function is a condenser, the second outdoor heat exchanger is in a resting state with the first outdoor heat exchanger functioning as a condenser. First control means for functioning as a condenser;
And a second control means for putting the first outdoor heat exchanger into a dormant state in a state where the first and second outdoor heat exchangers function as a condenser. Air conditioner.

In the air conditioning apparatus according to claim 1 or 2,
The outdoor unit and the plurality of indoor units are connected by inter-unit piping having a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe, and are configured to be able to perform a cooling operation or a heating operation for each indoor unit. An air conditioner characterized.

An outdoor unit having a compressor and a plurality of outdoor heat exchangers connected in parallel and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, and the indoor unit is cooled or heated. In the control method of the air conditioner configured to be able to perform,
Of the plurality of outdoor heat exchangers, the first outdoor heat exchanger functioning as a condenser is put into a dormant state, and the second outdoor heat exchanger in a dormant state is made to function as a condenser In the state where the first outdoor heat exchanger is functioning as a condenser, a first control process for causing the second outdoor heat exchanger in a dormant state to function as a condenser,
And a second control process for putting the first outdoor heat exchanger in a dormant state in a state where the first and second outdoor heat exchangers function as a condenser. Control method of air conditioner.

An outdoor unit having a compressor and a plurality of outdoor heat exchangers connected in parallel and a plurality of indoor units having an indoor heat exchanger are connected by inter-unit piping, and the indoor unit is cooled or heated. In the control method of the air conditioner configured to be able to perform,
Among the plurality of outdoor heat exchangers, the first outdoor heat exchanger functioning as a condenser is put into a dormant state, and the heat exchange capacity is smaller than the first outdoor heat exchanger and the dormant state. When the second outdoor heat exchanger as a function is a condenser, the second outdoor heat exchanger is in a resting state with the first outdoor heat exchanger functioning as a condenser. A first control process to function as a condenser;
And a second control process for putting the first outdoor heat exchanger in a dormant state in a state where the first and second outdoor heat exchangers function as a condenser. Control method of air conditioner.