JP2004324947A

JP2004324947A - Air conditioning system

Info

Publication number: JP2004324947A
Application number: JP2003117817A
Authority: JP
Inventors: Junichi Kameyama; 純一亀山; Tomohiko Kasai; 智彦河西
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2003-04-23
Filing date: 2003-04-23
Publication date: 2004-11-18

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning system having cost and energy saving effects by using normal indoor units as they are to produce required sensible heat capability even when using parts of the indoor units in a site such as a computer room in a building where there is a great sensible heat load. <P>SOLUTION: The air conditioning system comprises a heat source machine A having a compressor 1, the plurality of indoor units B, C, D each having an indoor side heat exchanger 5, and a relay E for connecting the heat source machine A to each indoor unit via first and second connecting pipes 6, 7 and switchably connecting the indoor side heat exchanger 5 to the first and second connecting pipes, the relay E consisting of a first branch portion 10 switchable to the first connecting pipe 6 via a capillary tube 22 and a second branch portion 11 connectable to the second connecting pipe 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
この発明は、空気調和装置に関し、特に熱源機１台に対して複数台の室内機を接続する多室型ヒートポンプ空気調和装置で、各室内機毎に冷暖房を選択的に行うことができ、冷房を行う室内機と暖房を行う室内機とを同時に運転することができる空気調和装置に関するものである。
【０００２】
【従来の技術】
図７は下記の特許文献に示された従来例の空気調和装置の全体構成を示す冷媒回路図である。この図において、Ａは熱源機、Ｂ，Ｃ，Ｄは後述するように互いに並列接続された複数台の室内機で、それぞれ同じ構成とされている。Ｅは熱源機Ａと室内機Ｂ，Ｃ，Ｄとを接続する中継機で、構成については後述する。
【０００３】
【特許文献１】特開平４−３３５９６７号公報（図１）
【０００４】
図７において、熱源機Ａは以下に述べる各構成要素によって構成されている。
即ち、１は圧縮機、２は圧縮機１に接続され冷媒の流通方向を切り換える四方切換弁、３は熱源機側熱交換器、４は四方切換弁２と圧縮機１との間に接続されたアキュムレータ、３２は熱源機側熱交換器３と後述する第２の接続配管７との間に設けられた第３の逆止弁であり、熱源機側熱交換器３から第２の接続配管７の方向へのみ冷媒流通を許容する。３３は四方切換弁２と後述する第１の接続配管６との間に設けられた第４の逆止弁であり、第１の接続配管６から四方切換弁２の方向へのみ冷媒流通を許容する。３４は四方切換弁２と第２の接続配管７との間に設けられた第５の逆止弁であり、四方切換弁２から第２の接続配管７の方向へのみ冷媒流通を許容する。３５は熱源機側熱交換器３と第１の接続配管６との間に設けられた第６の逆止弁であり、第１の接続配管６から熱源機側熱交換器３の方向へのみ冷媒流通を許容する。
【０００５】
また、室内機Ｂ，Ｃ，Ｄは、それぞれ室内側熱交換器５と、各室内側熱交換器５に近接して室内側熱交換器５に直列接続された第１の流量制御装置９とで構成されている。なお、第１の流量制御装置９は、冷房時は室内側熱交換器５の出口側の過熱度により、暖房時には同じく出口側の過冷却度により開閉状態が制御されている。更に、中継機Ｅは、四方切換弁２と接続された太い第１の接続配管６、及び熱源機側熱交換器３と接続され第１の接続配管６より細い第２の接続配管７によって熱源機Ａと接続され、室内機Ｂ，Ｃ，Ｄの室内側熱交換器５と接続された室内機側の第１の接続配管６ｂ，６ｃ，６ｄおよび室内機Ｂ，Ｃ，Ｄの第１の流量制御装置９に接続された室内機側の第２の接続配管７ｂ，７ｃ，７ｄによって各室内機Ｂ，Ｃ，Ｄと接続されると共に、以下に述べるような内部構成を有する。
【０００６】
即ち、１０は室内機側の第１の接続配管６ｂ，６ｃ，６ｄを、第１の接続配管６または第２の接続配管７に選択的に接続する第１の分岐部で、一端が室内機側の第１の接続配管６ｂ，６ｃ，６ｄにそれぞれ接続され、他端が一括接続されて第１の接続配管６に接続された３個の第１の弁装置８ａと、一端が室内機側の第１の接続配管６ｂ，６ｃ，６ｄにそれぞれ接続され、他端が一括接続されて第２の接続配管７に接続された３個の第４の弁装置８ｂとから構成され、第１の弁装置８ａを開路、第４の弁装置８ｂを閉路することにより、室内機側の第１の接続配管６ｂ，６ｃ，６ｄを第１の接続配管６に接続し、また、第１の弁装置８ａを閉路、第４の弁装置８ｂを開路することにより、室内機側の第１の接続配管６ｂ，６ｃ，６ｄを第２の接続配管７に接続するものである。
【０００７】
１１は室内機側の第２の接続配管７ｂ，７ｃ，７ｄの会合部を有する第２の分岐部、１２は第２の接続配管７の途中に設けられた気液分離装置で、その気相部は、第２の接続配管７を経て第４の弁装置８ｂに接続され、その液相部は第２の分岐部１１に接続されている。１３は気液分離装置１２と第２の分岐部１１との間に接続された開閉自在な第３の流量制御装置、１４は第２の分岐部１１と上記第１の接続配管６を結ぶバイパス配管、１５はバイパス配管１４の途中に設けられた第４の流量制御装置、１６ｂ，１６ｃ，１６ｄは第２の分岐部１１内でバイパス配管１４の第３の流量制御装置１５の下流部分と各室内機側の第２の接続配管７ｂ，７ｃ，７ｄとの間でそれぞれ熱交換を行う第３の熱交換部である。
【０００８】
１６ａはバイパス配管１４の第４の流量制御装置１５の下流で第３の熱交換部１６ｂ，１６ｃ，１６ｄの更に下流部分と各室内機側の第２の接続配管７ｂ，７ｃ，７ｄの会合部との間で熱交換を行う第２の熱交換部、１９はバイパス配管１４の第２の熱交換部１６ａより更に下流部分と、気液分離装置１２及び第３の流量制御装置１３を接続する配管との間で熱交換を行う第１の熱交換部、１７は第２の分岐部１１と第１の接続配管６との間に接続された開閉自在な第５の流量制御装置である。
中継機Ｅは上述した第１の分岐部１０、第２の分岐部１１、気液分離装置１２、第３、第４、第５の流量制御装置１３，１５，１７、第１、第２、第３の熱交換部１９，１６ａ，１６ｂ，１６ｃ，１６ｄ、及びバイパス配管１４等を内蔵するものである。
【０００９】
このように構成された従来の空気調和装置によって、大きく３つの形態の運転が行われる。即ち、複数台の室内機の総てで冷房運転を行う場合と、複数台の室内機の総てで暖房運転を行う場合と、複数台の室内機のうち一部は冷房運転を行い、他の一部は暖房運転を行う場合（冷暖房同時運転）とであり、以下で冷房運転と暖房運転の場合の運転動作を説明する。
【００１０】
まず、図８の運転動作状態図を示す説明図にて、上述した運転の形態のうち冷房運転のみの場合について説明する。図８に冷媒の流れを実線矢印で示すように、圧縮機１より吐出された高温高圧の冷媒ガスは四方切換弁２を通り、熱源機側熱交換器３で熱交換して凝縮された後、第３の逆止弁３２、第２の接続配管７を通り、中継機Ｅへ流入する。中継機Ｅへ流入した冷媒は気液分離装置１２、第３の流量制御装置１３の順に通り、第２の分岐部１１へ流入する。
第２の分岐部１１へ流入した冷媒は、会合部で室内機側の第２の接続配管７ｂ，７ｃ，７ｄに分流すると共に、各室内機Ｂ，Ｃ，Ｄに流入し、各室内側熱交換器５の出口の過熱度により制御される第１の流量制御装置９により低圧まで減圧された後、室内側熱交換器５で室内空気と熱交換して蒸発しガス化され室内を冷房する。そして、ガス状態となった冷媒は、室内機側の第１の接続配管６ｂ，６ｃ，６ｄ、第１の分岐部１０の第１の弁装置８ａ、第１の接続配管６、第４の逆止弁３３、四方切換弁２、アキュムレータ４を経て圧縮機１に吸入される循環サイクルを構成し、冷房運転を行う。このとき、第１の弁装置８ａは開路、第４の弁装置８ｂは閉路されている。
【００１１】
また、この時、第１の接続配管６は低圧、第２の接続配管７は高圧のため必然的に第３の逆止弁３２、第４の逆止弁３３へ冷媒が流通する。また、このサイクルの時、第３の流量制御装置１３を通過した冷媒の一部がバイパス配管１４へ入り、第４の流量制御装置１５で低圧まで減圧されて、第３の熱交換部１６ｂ，１６ｃ，１６ｄで各室内機側の第２の接続配管７ｂ，７ｃ，７ｄとの間で熱交換を行い、更に、第２の熱交換部１６ａで第２の分岐部１１の各室内機側の第２の接続配管７ｂ，７ｃ，７ｄの会合部との間で熱交換を行い、更にまた、第１の熱交換部１９で第３の流量制御装置１３に流入する冷媒との間で熱交換を行い蒸発した冷媒は、第１の接続配管６へ入り、第４の逆止弁３３、四方切換弁２、アキュムレータ４を経て圧縮機１に吸入される。
一方、第１及び第２並びに第３の熱交換部１９，１６ａ，１６ｂ，１６ｃ，１６ｄで熱交換し、冷却され過冷却度を十分につけられた上記第２の分岐部１１の冷媒は冷房しようとしている室内機Ｂ，Ｃ，Ｄへ流入する。
【００１２】
次に、図８を用いて暖房運転のみの場合について説明する。この場合は、四方切換弁２が切り換えられ、冷媒の流れが図８に破線矢印で示すようになる。即ち、圧縮機１より吐出された高温高圧の冷媒ガスは四方切換弁２を通り、第５の逆止弁３４、第２の接続配管７を通り、中継機Ｅへ流入する。中継機Ｅへ流入した冷媒は気液分離装置１２、第２の接続配管７を経て第１の分岐部１０に流入する。第１の分岐部１０に流入した冷媒は、第４の弁装置８ｂ、室内機側の第１の接続配管６ｂ，６ｃ，６ｄを通り、各室内機Ｂ，Ｃ，Ｄに流入し、室内側熱交換器５で室内空気と熱交換して凝縮液化し、室内を暖房する。そして、液状態となった冷媒は、各室内側熱交換器５の出口の過冷却度により制御される第１の流量制御装置９を通り、室内機側の第２の接続配管７ｂ，７ｃ，７ｄから第２の分岐部１１に流入して会合部で合流し、更に第５の流量制御装置１７で低圧の気液二相状態まで減圧される。そして、低圧まで減圧された冷媒は、第１の接続配管６に至る。
【００１３】
また、室内機側の第２の接続配管７ｂ，７ｃ，７ｄから会合部で合流した冷媒の一部は、バイパス配管１４に流入し、第４の流量制御装置１５で減圧された後、第３の熱交換部１６ｂ，１６ｃ，１６ｄ、第２の熱交換部１６ａ、第１の熱交換部１９を経て第１の接続配管６に至り、上述した第５の流量制御装置１７からの冷媒と合流し、第６の逆止弁３５、熱源機側熱交換器３に流入し熱交換して蒸発しガス状態となった冷媒は、四方切換弁２、アキュムレータ４を経て圧縮機１に吸入される循環サイクルを構成し、暖房運転を行う。この時、第１の弁装置８ａ閉路、第４の弁装置８ｂは開路されている。また、第１の接続配管６が低圧、第２の接続配管７が高圧のため必然的に第５の逆止弁３４、第６の逆止弁３５へ冷媒は流通する。
【００１４】
【発明が解決しようとする課題】
従来の空気調和装置は以上のように構成されているため冷房運転の場合において、室内機の一部がビル等のコンピュータールーム等の顕熱負荷の大きい場所、即ち冷房負荷の内、顕熱比（冷房負荷に対する顕熱負荷の比率）の大きい場所に使用される場合には、他の通常冷房運転負荷の場所に使用されている室内機では必要な顕熱能力が得られないという問題があった。
また、顕熱負荷が大きく潜熱負荷（冷房負荷から顕熱負荷を除いた負荷）が小さいため、冷凍サイクルのバランス上、蒸発温度が低下して室内熱交換器が凍結して水漏れが発生するという問題点があった。
また、必要な顕熱能力を得るためには顕熱比の大きい専用の室内機を使用するか、または顕熱比は小さいが冷房能力の大きな室内機を使用する必要があり、コンピュータの増設などにより室内側の顕熱負荷が変動する場合には、その都度これらの室内機に入れ替える必要があり、余分な費用が発生するという問題があった。
また、必要な顕熱能力を得るためには圧縮機の運転容量を増加させて冷房能力を増加させる必要があったため、消費電力が大きくなるという問題点があった。
【００１５】
この発明は、このような問題点を解決するためになされたもので、室内機の一部がビル等のコンピュータールーム等の顕熱負荷の大きい場所に使用される場合でも、通常の室内機をそのまま使用して必要な顕熱能力が得られ、かつ省コストで省エネ効果が得られる空気調和装置を提供するものである。
【００１６】
【課題を解決するための手段】
この発明に係る空気調和装置は、圧縮機と、この圧縮機から吐出された冷媒の流路を切り換える四方切換弁と、この四方切換弁に接続された熱源機側熱交換器とを有する１台の熱源機、室内側熱交換器と、これに接続された流量制御装置とを有する複数台の室内機、及び熱源機と各室内機とを第１及び第２の接続配管を介して接続し、各室内側熱交換器の一方の端部を第１及び第２の接続配管に切り換え可能に接続すると共に各室内側熱交換器の一方の端部を毛細管を介して第１の接続配管に切り換え可能に接続する弁装置を有する第１の分岐部と、各室内側熱交換器の他方の端部を第２の接続配管に接続し得る第２の分岐部からなる中継機を備えたものである。
【００１７】
この発明に係る空気調和装置は、また、冷房運転時には各室内側熱交換器の一方の端部を毛細管を介して第１の接続配管に接続する場合と、各室内側熱交換器の一方の端部を毛細管を介さずに第１の接続配管に接続する場合とを各室内機毎に選択できるよう制御する弁装置制御部を設けたものである。
【００１８】
この発明に係る空気調和装置は、また、圧縮機と、この圧縮機から吐出された冷媒の流路を切り換える四方切換弁と、この四方切換弁に接続された熱源機側熱交換器とを有する１台の熱源機、室内側熱交換器と、これに接続された流量制御装置とを有する複数台の室内機、及び熱源機と各室内機とを第１及び第２の接続配管を介して接続し、各室内側熱交換器の一方の端部を第１及び第２の接続配管に切り換え可能に接続すると共に各室内側熱交換器の一方の端部を流量制御装置を介して第１の接続配管に切り換え可能に接続する弁装置を有する第１の分岐部と、各室内側熱交換器の他方の端部を第２の接続配管に接続し得る第２の分岐部からなる中継機を備えたものである。
【００１９】
この発明に係る空気調和装置は、また、冷房運転時には各室内側熱交換器の一方の端部を流量制御装置を介して第１の接続配管に接続する場合と、各室内側熱交換器の一方の端部を流量制御装置を介さずに第１の接続配管に接続する場合とを各室内機毎に選択できるよう制御する弁装置制御部を設けたものである。
【００２０】
この発明に係る空気調和装置は、また、圧縮機は容量可変な圧縮機を使用するものである。
【００２１】
この発明に係る空気調和装置は、また、第１の分岐部の弁装置は、各室内側熱交換器の一方の端部にそれぞれ並列的に接続された２つ以上の弁を有し、一方の弁は第１の接続配管に接続され、他方の弁は第２の接続配管に接続されているものである。
【００２２】
【発明の実施の形態】
実施の形態１．
以下、この発明の実施の形態１を図に基づいて詳細に説明する。
図１は、実施の形態１による空気調和装置の全体構成を示す冷媒回路図である。なお、図１では熱源機１台に室内機３台、中継機１台を接続した場合について説明するが、４台以上の室内機、及び２台以上の中継機を接続した場合でも同様の効果が得られる。
【００２３】
図１において、Ａは熱源機、Ｂ，Ｃ，Ｄは後述するように互いに並列接続された室内機で、それぞれ同じ構成となっている。Ｅは熱源機Ａと室内機Ｂ，Ｃ，Ｄとを接続する中継機で、構成については後述する。
熱源機Ａは以下に述べる各構成要素によって構成されている。即ち、１は圧縮機、２は圧縮機１に接続され冷媒の流通方向を切り換える四方切換弁、３は熱源機側熱交換器、４は四方切換弁２と圧縮機１との間に接続されたアキュムレータ、３２は熱源機側熱交換器３と後述する第２の接続配管７との間に設けられた第３の逆止弁であり、熱源機側熱交換器３から第２の接続配管７の方向へのみ冷媒流通を許容する。
３３は四方切換弁２と後述する第１の接続配管６との間に設けられた第４の逆止弁であり、第１の接続配管６から四方切換弁２の方向へのみ冷媒流通を許容する。３４は四方切換弁２と第２の接続配管７との間に設けられた第５の逆止弁であり、四方切換弁２から第２の接続配管７の方向へのみ冷媒流通を許容する。３５は熱源機側熱交換器３と第１の接続配管６との間に設けられた第６の逆止弁であり、第１の接続配管６から熱源機側熱交換器３の方向へのみ冷媒流通を許容する。
【００２４】
また、室内機Ｂ，Ｃ，Ｄは、それぞれ室内側熱交換器５と、各室内側熱交換器５に近接して室内側熱交換器５に直列接続された第１の流量制御装置９とで構成されている。なお、第１の流量制御装置９は、冷房時は室内側熱交換器５の出口側の過熱度により、暖房時には同じく出口側の過冷却度により開閉状態が制御されている。更に、中継機Ｅは、四方切換弁２と接続された太い第１の接続配管６、及び熱源機側熱交換器３と接続され第１の接続配管６より細い第２の接続配管７によって熱源機Ａと接続され、室内機Ｂ，Ｃ，Ｄの室内側熱交換器５と接続された室内機側の第１の接続配管６ｂ，６ｃ，６ｄおよび室内機Ｂ，Ｃ，Ｄの第１の流量制御装置９に接続された室内機側の第２の接続配管７ｂ，７ｃ，７ｄによって各室内機Ｂ，Ｃ，Ｄと接続されると共に、以下に述べるような内部構成を有する。
【００２５】
即ち、１０は室内機側の第１の接続配管６ｂ，６ｃ，６ｄを、第１の接続配管６または第２の接続配管７に選択的に接続する第１の分岐部で、一端が室内機側の第１の接続配管６ｂ，６ｃ，６ｄにそれぞれ接続され、他端が一括接続されて第１の接続配管６に接続された３個の第１の弁装置８ａと、一端が室内機側の第１の接続配管６ｂ，６ｃ，６ｄにそれぞれ毛細管２２を介して接続され、他端が一括接続されて第１の接続配管６に接続された３個の第２の弁装置２０と、一端が室内機側の第１の接続配管６ｂ，６ｃ，６ｄにそれぞれ接続され、他端が一括接続されて第２の接続配管７に接続された３個の第４の弁装置８ｂとから構成され、第１の弁装置８ａまたは第２の弁装置２０を開路、第４の弁装置８ｂを閉路することにより、室内機側の第１の接続配管６ｂ，６ｃ，６ｄを第１の接続配管６に接続し、また、第１の弁装置８ａ及び第２の弁装置２０を閉路、第４の弁装置８ｂを開路することにより、室内機側の第１の接続配管６ｂ，６ｃ，６ｄを第２の接続配管７に接続するものである。
【００２６】
１１は室内機側の第２の接続配管７ｂ，７ｃ，７ｄにそれぞれ逆並列関係に一端が接続された第１の逆止弁１７及び第２の逆止弁１８と、第１の逆止弁１７の各他端を一括接続した会合部１７Ａと、第２の逆止弁１８の各他端を一括接続した会合部１８Ａとを有する第２の分岐部、１２は第２の接続配管７の途中に設けられた気液分離装置で、その気相部は、第２の接続配管７を経て第１の分岐部１０の第４の弁装置８ｂに接続され、その液相部は第２の分岐部１１に接続されている。１３は気液分離装置１２と第２の分岐部１１との間に接続された開閉自在な第３の流量制御装置、１４は第２の分岐部１１と上記第１の接続配管６を結ぶバイパス配管、１５はバイパス配管１４の途中に設けられた第４の流量制御装置、１６はバイパス配管１４の第４の流量制御装置１５の下流部分と第３の流量制御装置１３から第２の分岐部１１の会合部１８Ａに至る配管との間で熱交換を行う第２の熱交換部、１９はバイパス配管１４の第２の熱交換部１６の下流部分と、気液分離装置１２と第３の流量制御装置１３を接続する配管との間で熱交換を行う第１の熱交換部、２１は上記第１、第２の弁装置８ａ，２０の開閉を制御する弁装置制御部、また、４５は第３の流量制御装置１３と気液分離装置１２とを接続する配管に取り付けた第１の圧力検出器、４６は第３の流量制御装置１３と第２の分岐部１１とを接続する配管に取り付けた第２の圧力検出器である。
【００２７】
このように構成された実施の形態１の空気調和装置によって、大きく３つの形態の運転が行われる。即ち、複数台の室内機の総てで冷房運転を行う場合と、複数台の室内機の総てで暖房運転を行う場合と、複数台の室内機のうち一部は冷房運転を行い、他の一部は暖房運転を行う場合（冷暖房同時運転）とである。更に、冷暖房同時運転については、２つの形態の運転が行われる。即ち、複数の室内機のうち大部分の室内機が暖房運転を行う場合（暖房主体運転）と、複数の室内機のうち大部分が冷房運転を行う場合（冷房主体運転）とである。以下で上記各運転における運転状態を説明する。
【００２８】
まず、図２を用いて冷房運転のみの場合について説明する。図２に冷媒の流れを実線矢印で示すように、圧縮機１より吐出された高温高圧の冷媒ガスは四方切換弁２を通り、熱源機側熱交換器３で熱交換して凝縮された後、第３の逆止弁３２、第２の接続配管７を通り、中継機Ｅへ流入する。
中継機Ｅへ流入した冷媒は気液分離装置１２、第３の流量制御装置１３の順に通り、第２の分岐部１１へ流入する。第２の分岐部１１へ流入した冷媒は、会合部１７Ａで室内機側の第２の接続配管７ｂ，７ｃ，７ｄに分流すると共に、各室内機Ｂ，Ｃ，Ｄに流入し、各室内側熱交換器５の出口の過熱度により制御される第１の流量制御装置９により低圧まで減圧された後、室内側熱交換器５で室内空気と熱交換して蒸発しガス化され室内を冷房する。そして、ガス状態となった冷媒は、室内機側の第１の接続配管６ｂ，６ｃ，６ｄ、第１の分岐部１０の第１の弁装置８ａまたは第２の弁装置２０を通り、第１の接続配管６、第４の逆止弁３３、四方切換弁２、アキュムレータ４を経て圧縮機１に吸入される循環サイクルを構成し、冷房運転を行う。このとき、第１の弁装置８ａまたは第２の弁装置２０は開路、第４の弁装置８ｂは閉路されている。
【００２９】
また、この時、第１の接続配管６は低圧、第２の接続配管７は高圧のため必然的に第３の逆止弁３２、第４の逆止弁３３へ冷媒が流通する。また、このサイクルの時、第３の流量制御装置１３を通過した冷媒の一部がバイパス配管１４へ入り、第４の流量制御装置１５で低圧まで減圧されて、第２の熱交換部１６で各室内機側の第２の分岐部１１に流入する冷媒との間で熱交換を行い、また、第１の熱交換部１９で第３の流量制御装置１３に流入する冷媒との間で熱交換を行い蒸発した冷媒は、第１の接続配管６へ入り、第４の逆止弁３３、四方切換弁２、アキュムレータ４を経て圧縮機１に吸入される。一方、第１の熱交換部１９で熱交換し、冷却され過冷却度を十分につけられた上記第２の分岐部１１の冷媒は、第１の逆止弁１７、室内側の第２の接続配管７ｂ，７ｃ，７ｄを経由して冷房しようとしている室内機Ｂ，Ｃ，Ｄへ流入する。
【００３０】
弁装置制御部２１では冷房しようとしている室内機Ｂ，Ｃ，Ｄの室内側熱交換器５のいずれかの蒸発温度を高くする場合には、その室内機に相当する第１の弁装置８ａを閉、第２の弁装置２０を開とする制御を行い、冷房しようとしている室内機Ｂ，Ｃ，Ｄの室内側熱交換器５のいずれかの蒸発温度を通常の温度、または低くする場合には、その室内機に相当する第１の弁装置８ａを開、第２の弁装置２０を閉とする制御を行う。すなわち、第１の弁装置８ａを開、第２の弁装置２０を閉とした場合には、毛細管２２を経由せず冷媒が流通するため圧力損失が小さく室内側熱交換器５の蒸発温度を通常の温度または低くすることができる。
一方、第１の弁装置８ａを閉、第２の弁装置２０を開とした場合には、毛細管２２を経由して冷媒が流通するため圧力損失が大きく室内側熱交換器５の蒸発温度を高くすることが可能となる。このように、各室内機側熱交換器５の蒸発温度を選択的に高くすることが可能となる。
【００３１】
更に、圧縮機１にインバータコントロール等により容量可変な圧縮機を使用した場合には、圧縮機の運転容量を可変することで室内側熱交換器５での蒸発温度の設定をきめ細かく任意の温度に制御することが可能となる。すなわち、室内側熱交換器５での蒸発温度を上げる場合には圧縮機１の運転容量を小さくするよう制御を行い、逆に室内側熱交換器５での蒸発温度を下げる場合には圧縮機１の運転容量を大きくするよう制御を行う。
【００３２】
ここで、図５を用いて冷房運転時における室内側熱交換器の蒸発温度と顕熱能力との関係を説明する。図５は一般的な室内熱交換器を使用した時のある一定の空気条件下（一定の乾球温度及び湿球温度）での冷房運転時における蒸発温度を冷房能力（潜熱能力と顕熱能力の合計）、顕熱能力、顕熱比（冷房能力に対する顕熱能力の割合）を示した図であり、横軸が蒸発温度、縦軸左が冷房能力及び顕熱能力、縦軸右が顕熱比を示したものである。図５に示されているように蒸発温度が上昇すると冷房能力は減少するが、顕熱能力はほぼ一定能力を維持する。即ち、蒸発温度が上昇するほど顕熱比が大きくなる。
【００３３】
従って、コンピュータールームのように顕熱負荷が大きい場所で、その顕熱負荷に合致するように室内機の容量の選定を実施する場合には、通常の蒸発温度または蒸発温度が低い場合で選定すると大きな冷房能力を持った室内機、即ち製品形状が大きな室内機を選定する必要があるが、蒸発温度を上げることにより顕熱比が大きくなるので、小さな冷房能力を持った室内機、即ち製品形状が小さな室内機を選定することが可能となり、費用削減が可能となる。また、大きな冷房能力を持った室内機を使用して必要な顕熱能力を得ようとすると冷房能力が大きくなるため、冷凍サイクル上のバランスにおいて蒸発温度の低下を招き、室内側熱交換器が凍結して水漏れを引き起こす不具合が発生する可能性があるが、蒸発温度を上げることによりこの不具合を防止できる。
また、圧縮機としてインバータコントロール等による容量可変な圧縮機を使用した場合には、蒸発温度を上げるため圧縮機の運転容量を小さくできるので、消費電力の低減が可能であるため省エネ効果を得ることが可能となる。
【００３４】
上述した実施例１では、中継機を接続した冷凍サイクルで説明したが、熱源機と室内機のみとで構成される冷凍サイクルにおいても、容量可変な圧縮機を使用することで蒸発温度を上げることが可能であり、同様の効果を得ることができる。
【００３５】
次に、図２を用いて暖房運転のみの場合について説明する。この場合は、四方切換弁２が切り換えられ、冷媒の流れが図２に破線矢印で示すようになる。即ち、圧縮機１より吐出された高温高圧の冷媒ガスは四方切換弁２を通り、第５の逆止弁３４、第２の接続配管７を通り、中継機Ｅへ流入する。中継機Ｅへ流入した冷媒は気液分離装置１２、第２の接続配管７を経て第１の分岐部１０に流入する。第１の分岐部１０に流入した冷媒は、第４の弁装置８ｂ、室内機側の第１の接続配管６ｂ，６ｃ，６ｄを通り、各室内機Ｂ，Ｃ，Ｄに流入し、室内側熱交換器５で室内空気と熱交換して凝縮液化し、室内を暖房する。そして、液状態となった冷媒は、各室内側熱交換器５の出口の過冷却度により制御される第１の流量制御装置９を通り、室内機側の第２の接続配管７ｂ，７ｃ，７ｄから第２の分岐部１１に流入し、第２の逆止弁１８を通った後、会合部１８Ａで合流し、ここから第４の流量制御装置１５に流入して低圧の気液二相状態まで減圧される。低圧まで減圧された冷媒は、バイパス配管１４、第２の熱交換部１６、第１の熱交換部１９を経た後、第１の接続配管６に通り、第６の逆止弁３５、熱源機側熱交換器３に流入し熱交換して蒸発しガス状態となった冷媒は、四方切換弁２、アキュムレータ４を経て圧縮機１に吸入される循環サイクルを構成し、暖房運転を行う。
この時、第１及び第２の弁装置８ａ，２０は閉路、第４の弁装置８ｂは開路されている。また、第１の接続配管６が低圧、第２の接続配管７が高圧のため必然的に第５の逆止弁３４、第６の逆止弁３５へ冷媒は流通する。
【００３６】
次に、冷暖房同時運転における暖房主体の場合について図３を用いて説明する。ここでは室内機Ｂ，Ｃの２台が暖房、室内機Ｄの１台が冷房しようとしている場合について説明する。即ち、図３に実線矢印で示すように圧縮機１より吐出された高温高圧の冷媒ガスは四方切換弁２、第５の逆止弁３４、第２の接続配管７を通り、中継機Ｅに流入する。中継機Ｅに流入した冷媒は気液分離装置１２を経て、第１の分岐部１０に流入する。第１の分岐部１０へ流入した冷媒は、室内機Ｂ，Ｃに接続された第４の弁装置８ｂ、室内機側の第１の接続配管６ｂ，６ｃの順に通り、暖房しようとしている室内機Ｂ，Ｃに流入し、室内側熱交換器５で室内空気と熱交換して凝縮液化し、室内を暖房する。そして、この液状態となった冷媒は、室内側熱交換器５の出口の過冷却度により制御され、ほぼ全開状態の第１の流量制御装置９を通り少し減圧されて高圧と低圧の中間の圧力（中間圧）になり、室内機側の第２の接続配管７ｂ，７ｃから第２の逆止弁１８を通り会合部１８Ａで合流する。
【００３７】
冷房しようとしている室内機Ｄへの冷媒の流れは、中継機Ｅの第２の分岐部１１の会合部１８Ａで合流した冷媒の一部が第２の熱交換部１６を経て第２の分岐部１１の会合部１７Ａに至り、室内機Ｄに接続された第１の逆止弁１７、室内側の第２の接続配管７ｄを通り、室内側熱交換器５に入り熱交換して蒸発しガス状態となって室内を冷房し、第１の分岐部１０の室内機Ｄに接続された第１の弁装置８ａまたは第２の弁装置２０を介して第１の接続配管６に流入する。
一方、室内機Ｂ，Ｃから中継機Ｅの第２の分岐部１１の会合部１８Ａに流入した室内機Ｂ，Ｃの暖房用の冷媒の他の一部は、第２の接続配管７の高圧と第２の分岐部１１の中間圧との差を一定にするように制御される開閉自在な第４の流量制御装置１５を通って、バイパス配管１４に流入し、第１の接続配管６に至るため、ここで室内機Ｄを冷房した冷媒と合流して太い第１の接続配管６に流入し、第６の逆止弁３５、熱源機側熱交換器３に流入し熱交換して蒸発しガス状態となった冷媒は、四方切換弁２、アキュムレータ４を経て圧縮機１に吸入される循環サイクルを構成し、暖房主体運転を行う。
【００３８】
このとき、暖房しようとしている室内機Ｂ，Ｃに接続される第１、第２の弁装置８ａ，２０は閉路、第４の弁装置８ｂは開路され、冷房しようとしている室内機Ｄに接続される第１の弁装置８ａまたは第２の弁装置２０は開路、第４の弁装置８ｂは閉路されている。また、第１の接続配管６が低圧、第２の接続配管７が高圧のため必然的に第５の逆止弁３４、第６の逆止弁３５へ冷媒は流通する。
【００３９】
また、このサイクルの時、バイパス配管１４へ入った冷媒は、第４の流量制御装置１５で低圧まで減圧されて、第２の熱交換部１６で第２の分岐部１１へ流入する冷媒との間で、更に第１の熱交換部１９で第３の流量制御装置１３へ流入する冷媒との間で熱交換を行い蒸発した冷媒は、第１の接続配管６へ入り、第６の逆止弁３５を経て、熱源機側熱交換器３に流入し熱交換して蒸発しガス状態となる。そして、この冷媒は四方切換弁２、アキュムレータ４を経て圧縮機１に吸入される。一方、第１及び第２の熱交換部１９，１６で熱交換し冷却され過冷却度を十分につけられた冷媒は冷房しようとしている室内機Ｄへ流入する。
【００４０】
この暖房主体運転時において弁装置制御部２１では冷房しようとしている室内機Ｄの室内側熱交換器５の蒸発温度を高くする場合には、その室内機に相当する第１の弁装置８ａを閉、第２の弁装置２０を開とする制御を行い、冷房しようとしている室内機Ｄの室内側熱交換器５の蒸発温度を通常の温度、または低くする場合には、その室内機に相当する第１の弁装置８ａを開、第２の弁装置２０を閉とする制御を行う。すなわち、第１の弁装置８ａを開、第２の弁装置２０を閉とした場合には、毛細管２２を経由せず冷媒が流通するため圧力損失が小さく室内側熱交換器５の蒸発温度を通常の温度または低くすることができる。一方、第１の弁装置８ａを閉、第２の弁装置２０を開とした場合には、毛細管２２を経由して冷媒が流通するため圧力損失が大きく室内側熱交換器５の蒸発温度を高くすることが可能となる。このように、各室内側熱交換器５の蒸発温度を選択的に高くすることが可能となる。
このように、冷房しようとする室内機Ｄの蒸発温度を選択的に制御することの効果は、前述した冷房運転時の効果と同じであるので、ここでは説明を省略する。
【００４１】
次に、冷暖房同時運転における冷房主体の場合について図４を用いて説明する。ここでは、室内機Ｂ，Ｃの２台が冷房、室内機Ｄの１台が暖房しようとしている場合について説明する。即ち、図４に冷媒の流れを実線矢印で示すように、圧縮機１より吐出された高温高圧の冷媒ガスは四方切換弁２を通り、熱源機側熱交換器３で任意量熱交換して気液２相の高温高圧冷媒となり、第３の逆止弁３２、第２の接続配管７を通り、中継機Ｅに流入する。中継機Ｅに流入した冷媒は気液分離装置１２へ送られ、ここで、ガス冷媒と液冷媒に分離され、分離されたガス冷媒は、第２の接続配管７を経て中継機Ｅの第１の分岐部１０の第４の弁装置８ｂ、室内機側の第１の接続配管６ｄの順に通り、暖房しようとしている室内機Ｄに流入し、室内側熱交換器５で室内空気と熱交換して凝縮液化し、室内を暖房する。
【００４２】
更に、室内側熱交換器５の出口の過冷却度により制御されほぼ全開状態の第１の流量制御装置９を通り少し減圧されて、高圧と低圧の中間の圧力（中間圧）となり、室内側の第２の接続配管７ｄを経て、第２の分岐部１１の第２の逆止弁１８を通り会合部１８Ａからバイパス配管１４に流入し、第４の流量制御装置１５で低圧まで減圧されて、第２の熱交換部１６で第２の分岐部１１に流入する冷媒との間で熱交換を行い、また、第１の熱交換部１９で第３の流量制御装置１３へ流入する冷媒との間で熱交換を行い蒸発した冷媒は、第１の接続配管６に至る。
一方、中継機Ｅの気液分離装置１２で分離された残りの液冷媒は、第１の熱交換部１９で熱交換して冷却され過冷却度を十分につけた後、高圧と中間圧の差を一定にするように制御される第３の流量制御装置１３を通って第２の分岐部１１の会合部１７Ａに流入する。
【００４３】
冷房しようとしている室内機Ｂ，Ｃへの冷媒の流れは、中継機Ｅの第２の分岐部１１の会合部１７Ａから室内機Ｂ，Ｃに接続された第１の逆止弁１７、室内機側の第２の接続配管７ｂ，７ｃを通り、各室内機Ｂ，Ｃに流入する。そして、この冷媒は、室内機Ｂ，Ｃの室内側熱交換器５の出口の過熱度により制御される第１の流量制御装置９により低圧まで減圧されて室内側熱交換器５で室内空気と熱交換して蒸発しガス化され室内を冷房する。そして、このガス状態となった冷媒は、室内機側の第１の接続配管６ｂ，６ｃ、第１の分岐部１０の第１の弁装置８ａまたは第２の弁装置２０を経て、第１の接続配管６へ流入し、バイパス配管１４を経て第１の接続配管６に流入する上述の室内機Ｄの暖房用冷媒と合流した後、第４の逆止弁３３、四方切換弁２、アキュムレータ４を経て圧縮機１に吸入される循環サイクルを構成し、冷房主体運転を行う。
【００４４】
この時、冷房しようとしている室内機Ｂ，Ｃに接続される第１の弁装置８ａまたは第２の弁装置２０は開路、第４の弁装置８ｂは閉路され、暖房しようとしている室内機Ｄに接続される第１、第２の弁装置８ａ，２０は閉路、第４の弁装置８ｂは開路されている。また、第１の接続配管６は低圧、第２の接続配管７は高圧のため必然的に第３の逆止弁３２、第４の逆止弁３３へ冷媒は流通する。
【００４５】
この冷房主体運転時において弁装置制御部２１では冷房しようとしている室内機Ｂ，Ｃの室内側熱交換器５のいずれかの蒸発温度を高くする場合には、その室内機に相当する第１の弁装置８ａを閉、第２の弁装置２０を開とする制御を行い、冷房しようとしている室内機Ｂ，Ｃの室内側熱交換器５のいずれかの蒸発温度を通常の温度、または低くする場合には、その室内機に相当する第１の弁装置８ａを開、第２の弁装置２０を閉とする制御を行う。すなわち、第１の弁装置８ａを開、第２の弁装置２０を閉とした場合には、毛細管２２を経由せず冷媒が流通するため圧力損失が小さく室内側熱交換器５の蒸発温度を通常の温度または低くすることができる。一方、第１の弁装置８ａを閉、第２の弁装置２０を開とした場合には、毛細管２２を経由して冷媒が流通するため圧力損失が大きく室内側熱交換器５の蒸発温度を高くすることが可能となる。このように、各室内側熱交換器５の蒸発温度を選択的に高くすることが可能となる。
このように、冷房しようとする室内機Ｂ，Ｃの蒸発温度を選択的に制御することの効果は、前述した冷房運転時の効果と同じであるので、ここでは説明を省略する。
【００４６】
実施の形態２．
次に、この発明の実施の形態２を図６に基づいて詳細に説明する。
図６は、実施の形態２の全体構成を示す冷媒回路図である。この図において、図１と同一または相当部分には同一符号を付して説明を省略する。図６において、２３は一端が室内機側の第１の接続配管６ｂ，６ｃ，６ｄにそれぞれ接続され、他端が一括接続されて第１の接続配管６に接続された３個の第２の弁装置２０と第１の接続配管６ｂ，６ｃ，６ｄとの間に介在する第２の流量制御装置であり、冷房運転時に第１の接続配管６ｂ，６ｃ，６ｄから第１の接続配管６へ流通する冷媒の圧力損失をコントロールする。
２４は第２の流量制御装置２３の弁開度をコントロールする流量制御装置制御部であり、冷房運転時に室内側熱交換器における蒸発温度を任意に高くコントロールすることが可能である。
また、冷房運転、暖房運転、冷暖房同時運転（冷房主体運転及び暖房主体運転）時における冷媒の流れは、上述した実施の形態１と同じであるため説明は省略する。
【００４７】
ここで実施例２における冷房運転時の弁装置制御部２１及び流量制御装置制御部２４について説明する。
弁装置制御部２１では冷房しようとしている室内機Ｂ，Ｃ，Ｄの室内側熱交換器５のいずれかの蒸発温度を高くする場合には、その室内機に相当する第１の弁装置８ａを閉、第２の弁装置２０を開とする制御を行い、冷房しようとしている室内機Ｂ，Ｃ，Ｄの室内側熱交換器５のいずれかの蒸発温度を通常の温度、または低くする場合には、その室内機に相当する第１の弁装置８ａを開、第２の弁装置２０を閉とする制御を行う。すなわち、第１の弁装置８ａを開、第２の弁装置２０を閉とした場合には、第２の流量制御装置２３を経由せず冷媒が流通するため圧力損失が小さく室内側熱交換器５の蒸発温度を通常の温度または低くすることができる。一方、第１の弁装置８ａを閉、第２の弁装置２０を開とした場合には、第２の流量制御装置２３を経由して冷媒が流通するため圧力損失が大きく室内側熱交換器５の蒸発温度を高くすることが可能となる。
【００４８】
このとき、流量制御装置制御部２４により第２の流量制御装置２３の弁開度を任意にコントロールすることによって、第２の流量制御装置２３を経由して冷媒が流通するときの圧力損失を任意にコントロールできるので、各室内側熱交換器５の蒸発温度を選択的に、かつ任意の温度に高くすることが可能となる。また、室内機Ｂ，Ｃ，Ｄの一部がビル等のコンピュータールーム等の顕熱負荷の大きい場所に使用される場合にでも通常の室内機をそのまま使用して蒸発温度を任意の温度に高くコントロールして顕熱比の大きな運転を実施できるので、必要な顕熱能力をきめ細かく任意の温度に設定できると共に、低コストで実現することができる。
【００４９】
更に、圧縮機１にインバータコントロール等により容量可変な圧縮機を使用した場合には、圧縮機の運転容量の可変によるコントロールと、第２の流量制御装置２３の弁開度コントロールとの組合せで、室内側熱交換器５での蒸発温度の設定を各室内機の使用環境に応じてきめ細かく任意の温度に制御し、かつ消費電力を小さくする運転を自動的に実施することが可能となる。すなわち、室内機Ｂ，Ｃ，Ｄ全ての蒸発温度を高くする場合には、圧縮機１の運転容量を小さくするよう制御を行い消費電力を低減して省エネ運転を優先して行い、また、室内機の一部が通常の空調負荷の場所で使用され通常の冷房能力が必要であり、かつ他の室内機はコンピュータールームなど顕熱能力が大きい場所で使用され顕熱比を大きく設定したい場合、即ち蒸発温度を高く設定したい場合には、第２の流量制御装置２３の弁開度のコントロールのみで蒸発温度を高くするコントロールを行なうことで、通常の空調負荷で使用している室内機の冷房能力を減少させることなく運転を実施できる。このように個々の室内機の使用環境が異なっていても、蒸発温度コントロールと省エネ運転を自動的に切り換え可能となる。
【００５０】
【発明の効果】
この発明に係る空気調和装置では、室内機の一部がビル等のコンピュータールーム等の顕熱負荷の大きい場所に使用される場合でも、通常の室内機をそのまま使用して蒸発温度を高くコントロールして顕熱比の大きな運転を実施できるので、必要な顕熱能力を低コストで得ることができる。
【図面の簡単な説明】
【図１】この発明の実施の形態１を示す空気調和装置の全体構成図である。
【図２】図１に示す空気調和装置の冷房又は暖房のみの運転動作状態図である。
【図３】図１に示す空気調和装置の暖房主体の運転動作状態図である。
【図４】図１に示す空気調和装置の冷房主体の運転動作状態図である。
【図５】冷房運転時の室内側熱交換器の蒸発温度と顕熱能力の関係を示す図である。
【図６】この発明の実施の形態２を示す空気調和装置の全体構成図である。
【図７】従来の空気調和装置の全体構成図である。
【図８】図７に示す空気調和装置の冷房又は暖房のみの運転動作状態図である。
【符号の説明】
１圧縮機、２四方切換弁、３熱源機側熱交換器、４アキュムレータ、５室内側熱交換器、６第１の接続配管、６ｂ，６ｃ，６ｄ室内機側の第１の接続配管、７第２の接続配管、７ｂ，７ｃ，７ｄ室内機側の第２の接続配管、８ａ第１の弁装置、８ｂ第４の弁装置、９第１の流量制御装置、１０第１の分岐部、１１第２の分岐部、１２気液分離装置、１３第３の流量制御装置、１４バイパス配管、１５第４の流量制御装置、１６第２の熱交換部、１７第１の逆止弁、１７Ａ，１８Ａ会合部、１８第２の逆止弁、１９第１の熱交換部、２０第２の弁装置、２１弁装置制御部、２２毛細管、２３第２の流量制御装置、２４流量制御装置制御部、２５第３の熱交換部、２６第１の温度検出器、２７第２の温度検出器、３２第３の逆止弁、３３第４の逆止弁、３４第５の逆止弁、３５第６の逆止弁、４５第１の圧力検出器、４６第２の圧力検出器、Ａ熱源機、Ｂ，Ｃ，Ｄ室内機、Ｅ中継機。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air conditioner, and more particularly, to a multi-room heat pump air conditioner in which a plurality of indoor units are connected to one heat source unit, and air conditioning can be selectively performed for each indoor unit. The present invention relates to an air conditioner that can simultaneously operate an indoor unit that performs heating and an indoor unit that performs heating.
[0002]
[Prior art]
FIG. 7 is a refrigerant circuit diagram showing an entire configuration of a conventional air conditioner disclosed in the following Patent Document. In this figure, A is a heat source unit, and B, C and D are a plurality of indoor units connected in parallel to each other as described later, and have the same configuration. E is a repeater that connects the heat source unit A and the indoor units B, C, and D, and the configuration will be described later.
[0003]
[Patent Document 1] Japanese Patent Application Laid-Open No. 4-335959 (FIG. 1)
[0004]
In FIG. 7, the heat source device A is constituted by the components described below.
That is, 1 is a compressor, 2 is a four-way switching valve that is connected to the compressor 1 and switches the flow direction of the refrigerant, 3 is a heat source side heat exchanger, and 4 is connected between the four-way switching valve 2 and the compressor 1. The accumulator 32 is a third check valve provided between the heat source unit side heat exchanger 3 and a second connection pipe 7 described below, and is connected to the second connection pipe from the heat source unit side heat exchanger 3. The refrigerant flow is allowed only in the direction of 7. Reference numeral 33 denotes a fourth check valve provided between the four-way switching valve 2 and a first connection pipe 6 which will be described later, and allows refrigerant to flow only in the direction from the first connection pipe 6 to the four-way switching valve 2. I do. Reference numeral 34 denotes a fifth check valve provided between the four-way switching valve 2 and the second connection pipe 7, and allows the refrigerant to flow only in the direction from the four-way switching valve 2 to the second connection pipe 7. Reference numeral 35 denotes a sixth check valve provided between the heat source unit side heat exchanger 3 and the first connection pipe 6, and only in a direction from the first connection pipe 6 to the heat source unit side heat exchanger 3. Allow refrigerant flow.
[0005]
The indoor units B, C, and D each include an indoor heat exchanger 5 and a first flow control device 9 that is adjacent to each indoor heat exchanger 5 and connected in series to the indoor heat exchanger 5. It is composed of The opening and closing state of the first flow control device 9 is controlled by the degree of superheat on the outlet side of the indoor heat exchanger 5 during cooling and by the degree of supercooling on the outlet side during heating. Further, the relay machine E is connected to the heat source side heat exchanger 3 by the thick first connection pipe 6 connected to the four-way switching valve 2 and the second connection pipe 7 thinner than the first connection pipe 6 by the heat source. The first connection pipes 6b, 6c, 6d on the indoor unit side connected to the indoor unit A and connected to the indoor heat exchangers 5 of the indoor units B, C, D and the first of the indoor units B, C, D Each of the indoor units B, C, and D is connected to each of the indoor units B, C, and D by the second connection pipes 7b, 7c, and 7d on the indoor unit side connected to the flow rate control device 9, and has an internal configuration described below.
[0006]
That is, reference numeral 10 denotes a first branch portion for selectively connecting the first connection pipes 6b, 6c, 6d on the indoor unit side to the first connection pipe 6 or the second connection pipe 7, and one end of the first branch unit. Three first valve devices 8a connected respectively to the first connection pipes 6b, 6c, and 6d on one side and the other end collectively connected to the first connection pipe 6, and one end connected to the indoor unit. Are connected to the first connection pipes 6b, 6c, and 6d, respectively, and are connected to the second connection pipe 7 at the other end, and are connected to the second connection pipe 7. By opening the valve device 8a and closing the fourth valve device 8b, the first connection pipes 6b, 6c, 6d on the indoor unit side are connected to the first connection pipe 6, and the first valve device is connected. By closing the circuit 8a and opening the fourth valve device 8b, the first connection pipes 6b, 6c, 6d on the indoor unit side are connected to the second connection. It is intended to be connected to the connection pipe 7.
[0007]
Reference numeral 11 denotes a second branch portion having an associated portion of the second connection pipes 7b, 7c, and 7d on the indoor unit side. Reference numeral 12 denotes a gas-liquid separation device provided in the middle of the second connection pipe 7, The portion is connected to the fourth valve device 8b via the second connection pipe 7, and the liquid phase portion is connected to the second branch portion 11. Reference numeral 13 denotes an openable and closable third flow control device connected between the gas-liquid separation device 12 and the second branch portion 11, and reference numeral 14 denotes a bypass connecting the second branch portion 11 and the first connection pipe 6. A pipe 15 is a fourth flow control device provided in the middle of the bypass pipe 14, and 16 b, 16 c, and 16 d are each a downstream portion of the third flow control device 15 of the bypass pipe 14 in the second branch portion 11. This is a third heat exchange section that exchanges heat with the second connection pipes 7b, 7c, 7d on the indoor unit side.
[0008]
Reference numeral 16a denotes a downstream of the fourth flow control device 15 of the bypass pipe 14, a downstream portion of the third heat exchangers 16b, 16c, and 16d, and a junction of the second connection pipes 7b, 7c, and 7d on the indoor unit side. A second heat exchange section 19 for exchanging heat between the second heat exchange section 19 and the downstream side of the second heat exchange section 16 a of the bypass pipe 14 connects the gas-liquid separation device 12 and the third flow control device 13. A first heat exchange section 17 for exchanging heat with the pipe is a fifth open / closed flow control device connected between the second branch section 11 and the first connection pipe 6.
The repeater E is provided with the first branch 10, the second branch 11, the gas-liquid separator 12, the third, fourth, and fifth flow controllers 13, 15, 17, the first, second, It incorporates the third heat exchange sections 19, 16a, 16b, 16c, 16d, the bypass pipe 14, and the like.
[0009]
With the conventional air conditioner configured as described above, three major modes of operation are performed. That is, a case where the cooling operation is performed by all of the plurality of indoor units, a case where the heating operation is performed by all of the plurality of indoor units, a portion of the plurality of indoor units perform the cooling operation, and Is a case where the heating operation is performed (simultaneous cooling and heating operation), and the operation of the cooling operation and the heating operation will be described below.
[0010]
First, a description will be given of a case of only the cooling operation in the above-described operation modes with reference to an explanatory diagram showing the operation state diagram of FIG. As shown by the solid arrows in FIG. 8, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, and is condensed by exchanging heat with the heat source device side heat exchanger 3. , Through the third check valve 32 and the second connection pipe 7, and flows into the repeater E. The refrigerant that has flowed into the repeater E flows into the second branch 11 in the order of the gas-liquid separator 12 and the third flow controller 13.
The refrigerant that has flowed into the second branch portion 11 branches into the second connection pipes 7b, 7c, and 7d on the indoor unit side at the meeting portion, flows into each of the indoor units B, C, and D, and receives heat from each of the indoor units. After the pressure is reduced to a low pressure by the first flow control device 9 controlled by the degree of superheat at the outlet of the exchanger 5, the indoor heat exchanger 5 exchanges heat with room air to evaporate and gasify, thereby cooling the room. . The gaseous refrigerant is supplied to the first connection pipes 6b, 6c, and 6d on the indoor unit side, the first valve device 8a of the first branch portion 10, the first connection pipe 6, and the fourth reverse pipe. A circulation cycle is drawn into the compressor 1 via the stop valve 33, the four-way switching valve 2, and the accumulator 4, and the cooling operation is performed. At this time, the first valve device 8a is open, and the fourth valve device 8b is closed.
[0011]
Further, at this time, the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, so that the refrigerant necessarily flows to the third check valve 32 and the fourth check valve 33. At the time of this cycle, a part of the refrigerant that has passed through the third flow control device 13 enters the bypass pipe 14 and is reduced to a low pressure by the fourth flow control device 15, so that the third heat exchange unit 16b, Heat exchange is performed between the second connection pipes 7b, 7c, and 7d on the indoor unit side at 16c and 16d, and further, on the indoor unit side of the second branch unit 11 at the second heat exchange unit 16a. The heat exchange is performed between the associated portions of the second connection pipes 7b, 7c, and 7d, and further, the heat exchange is performed between the first heat exchange unit 19 and the refrigerant flowing into the third flow control device 13. Then, the evaporated refrigerant enters the first connection pipe 6 and is sucked into the compressor 1 through the fourth check valve 33, the four-way switching valve 2, and the accumulator 4.
On the other hand, the first, second, and third heat exchangers 19, 16a, 16b, 16c, 16d exchange heat, and the refrigerant in the second branch 11, which has been cooled and provided with a sufficient degree of supercooling, will be cooled. Flows into the indoor units B, C, and D.
[0012]
Next, a case of only the heating operation will be described with reference to FIG. In this case, the four-way switching valve 2 is switched, and the flow of the refrigerant is as shown by the dashed arrow in FIG. That is, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 flows through the four-way switching valve 2, the fifth check valve 34 and the second connection pipe 7, and flows into the relay E. The refrigerant flowing into the repeater E flows into the first branch 10 via the gas-liquid separator 12 and the second connection pipe 7. The refrigerant flowing into the first branch portion 10 passes through the fourth valve device 8b and the first connection pipes 6b, 6c, and 6d on the indoor unit side, flows into the indoor units B, C, and D, and flows into the indoor side. The heat exchanger 5 exchanges heat with room air to condense and liquefy, thereby heating the room. Then, the refrigerant in a liquid state passes through the first flow control device 9 controlled by the degree of supercooling at the outlet of each indoor heat exchanger 5, and passes through the second connection pipes 7b, 7c, From 7d, the fluid flows into the second branch portion 11, merges at the meeting portion, and is further reduced to a low-pressure gas-liquid two-phase state by the fifth flow control device 17. Then, the refrigerant decompressed to a low pressure reaches the first connection pipe 6.
[0013]
In addition, a part of the refrigerant that has joined at the meeting portion from the second connection pipes 7b, 7c, and 7d on the indoor unit side flows into the bypass pipe 14, is depressurized by the fourth flow control device 15, and Through the heat exchange sections 16b, 16c, 16d, the second heat exchange section 16a, and the first heat exchange section 19 to reach the first connection pipe 6, and merge with the refrigerant from the fifth flow control device 17 described above. Then, the refrigerant which flows into the sixth check valve 35 and the heat source unit side heat exchanger 3 and exchanges heat to evaporate into a gaseous state is sucked into the compressor 1 via the four-way switching valve 2 and the accumulator 4. Constructs a circulation cycle and performs heating operation. At this time, the first valve device 8a is closed, and the fourth valve device 8b is open. In addition, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, the refrigerant necessarily flows to the fifth check valve 34 and the sixth check valve 35.
[0014]
[Problems to be solved by the invention]
Since the conventional air conditioner is configured as described above, in the case of the cooling operation, a part of the indoor unit has a large sensible heat load such as a computer room of a building or the like, that is, the sensible heat ratio among the cooling loads. When used in a place where the ratio of the sensible heat load to the cooling load is large, there is a problem that the required sensible heat capacity cannot be obtained in an indoor unit used in a place of another normal cooling operation load. Was.
In addition, since the sensible heat load is large and the latent heat load (load obtained by subtracting the sensible heat load from the cooling load) is small, the evaporation temperature drops due to the balance of the refrigeration cycle, the indoor heat exchanger freezes, and water leakage occurs. There was a problem.
In order to obtain the required sensible heat capacity, it is necessary to use a dedicated indoor unit with a large sensible heat ratio, or use an indoor unit with a small sensible heat ratio but a large cooling capacity. Therefore, when the sensible heat load on the indoor side fluctuates, it is necessary to replace these indoor units each time, and there is a problem that extra cost is generated.
Further, in order to obtain the required sensible heat capacity, it is necessary to increase the operating capacity of the compressor to increase the cooling capacity, so that there is a problem that power consumption is increased.
[0015]
The present invention has been made in order to solve such a problem, and even when a part of the indoor unit is used in a place having a large sensible heat load such as a computer room such as a building, a normal indoor unit is used. It is an object of the present invention to provide an air conditioner which can obtain a required sensible heat capacity by using it as it is, and at the same time can save cost and save energy.
[0016]
[Means for Solving the Problems]
An air conditioner according to the present invention includes a compressor, a four-way switching valve for switching a flow path of a refrigerant discharged from the compressor, and a heat source device-side heat exchanger connected to the four-way switching valve. A plurality of indoor units having a heat source unit, an indoor side heat exchanger, and a flow control device connected thereto, and a heat source unit and each indoor unit connected through first and second connection pipes. One end of each indoor heat exchanger is switchably connected to the first and second connection pipes, and one end of each indoor heat exchanger is connected to the first connection pipe via a capillary tube. A relay device comprising a first branch having a switchable connection valve device and a second branch capable of connecting the other end of each indoor heat exchanger to a second connection pipe. It is.
[0017]
The air conditioner according to the present invention also includes a case where one end of each indoor heat exchanger is connected to the first connection pipe via a capillary tube during cooling operation, and a case where one end of each indoor heat exchanger is connected. A valve device control unit is provided which controls so that the end unit can be selected for each indoor unit without being connected to the first connection pipe without passing through a capillary tube.
[0018]
The air conditioner according to the present invention further includes a compressor, a four-way switching valve for switching a flow path of the refrigerant discharged from the compressor, and a heat source device side heat exchanger connected to the four-way switching valve. One heat source unit, a plurality of indoor units having an indoor heat exchanger, and a flow control device connected thereto, and the heat source unit and each indoor unit are connected via first and second connection pipes. And one end of each indoor heat exchanger is switchably connected to the first and second connection pipes, and one end of each indoor heat exchanger is connected to the first end via a flow control device. A first branch unit having a valve device that is switchably connected to the second connection pipe, and a second branch unit that can connect the other end of each indoor heat exchanger to the second connection pipe. It is provided with.
[0019]
The air conditioner according to the present invention also includes a case where one end of each indoor heat exchanger is connected to the first connection pipe via the flow control device during the cooling operation, and a case where each indoor heat exchanger is A valve device control unit is provided which controls so as to be able to select, for each indoor unit, a case where one end is connected to the first connection pipe without passing through the flow control device.
[0020]
In the air conditioner according to the present invention, the compressor uses a variable capacity compressor.
[0021]
In the air conditioner according to the present invention, the valve device of the first branch portion includes two or more valves connected in parallel to one end of each indoor heat exchanger, respectively. Is connected to the first connection pipe, and the other valve is connected to the second connection pipe.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a refrigerant circuit diagram illustrating an overall configuration of the air-conditioning apparatus according to Embodiment 1. Although FIG. 1 illustrates a case where three indoor units and one relay unit are connected to one heat source unit, the same effect is obtained when four or more indoor units and two or more relay units are connected. Is obtained.
[0023]
In FIG. 1, A is a heat source unit, and B, C, and D are indoor units connected in parallel to each other as described later, and have the same configuration. E is a repeater that connects the heat source unit A and the indoor units B, C, and D, and the configuration will be described later.
The heat source device A is constituted by the components described below. That is, 1 is a compressor, 2 is a four-way switching valve that is connected to the compressor 1 and switches the flow direction of the refrigerant, 3 is a heat source side heat exchanger, and 4 is connected between the four-way switching valve 2 and the compressor 1. The accumulator 32 is a third check valve provided between the heat source unit side heat exchanger 3 and a second connection pipe 7 described below, and is connected to the second connection pipe from the heat source unit side heat exchanger 3. The refrigerant flow is allowed only in the direction of 7.
Reference numeral 33 denotes a fourth check valve provided between the four-way switching valve 2 and a first connection pipe 6 which will be described later, and allows refrigerant to flow only in the direction from the first connection pipe 6 to the four-way switching valve 2. I do. Reference numeral 34 denotes a fifth check valve provided between the four-way switching valve 2 and the second connection pipe 7, and allows the refrigerant to flow only in the direction from the four-way switching valve 2 to the second connection pipe 7. Reference numeral 35 denotes a sixth check valve provided between the heat source unit side heat exchanger 3 and the first connection pipe 6, and only in a direction from the first connection pipe 6 to the heat source unit side heat exchanger 3. Allow refrigerant flow.
[0024]
The indoor units B, C, and D each include an indoor heat exchanger 5 and a first flow control device 9 that is adjacent to each indoor heat exchanger 5 and connected in series to the indoor heat exchanger 5. It is composed of The opening and closing state of the first flow control device 9 is controlled by the degree of superheat on the outlet side of the indoor heat exchanger 5 during cooling and by the degree of supercooling on the outlet side during heating. Further, the relay machine E is connected to the heat source side heat exchanger 3 by the thick first connection pipe 6 connected to the four-way switching valve 2 and the second connection pipe 7 thinner than the first connection pipe 6 by the heat source. The first connection pipes 6b, 6c, 6d on the indoor unit side connected to the indoor unit A and connected to the indoor heat exchangers 5 of the indoor units B, C, D and the first of the indoor units B, C, D Each of the indoor units B, C, and D is connected to each of the indoor units B, C, and D by the second connection pipes 7b, 7c, and 7d on the indoor unit side connected to the flow rate control device 9, and has an internal configuration described below.
[0025]
That is, reference numeral 10 denotes a first branch portion for selectively connecting the first connection pipes 6b, 6c, 6d on the indoor unit side to the first connection pipe 6 or the second connection pipe 7, and one end of the first branch unit. Three first valve devices 8a connected respectively to the first connection pipes 6b, 6c, and 6d on one side and the other end collectively connected to the first connection pipe 6, and one end connected to the indoor unit. Three second valve devices 20 connected respectively to the first connection pipes 6b, 6c, and 6d via the capillaries 22, and the other ends are connected together and connected to the first connection pipe 6. Are connected to the first connection pipes 6b, 6c, and 6d on the indoor unit side, respectively, and the other ends are collectively connected to three fourth valve devices 8b connected to the second connection pipe 7. By opening the first valve device 8a or the second valve device 20 and closing the fourth valve device 8b, the indoor The first connection pipes 6b, 6c, 6d on the side are connected to the first connection pipe 6, the first valve device 8a and the second valve device 20 are closed, and the fourth valve device 8b is opened. Thus, the first connection pipes 6b, 6c, 6d on the indoor unit side are connected to the second connection pipe 7.
[0026]
Reference numeral 11 denotes a first check valve 17 and a second check valve 18 each having one end connected to the second connection pipe 7b, 7c, 7d on the indoor unit side in an anti-parallel relationship, and a first check valve. A second branch portion having an associated portion 17A integrally connected to the other ends of the respective 17 and an associated portion 18A integrally connected to the respective other ends of the second check valve 18; In the gas-liquid separation device provided on the way, the gas phase portion is connected to the fourth valve device 8b of the first branch portion 10 via the second connection pipe 7, and the liquid phase portion is connected to the second valve device 8b. It is connected to the branch unit 11. Reference numeral 13 denotes an openable and closable third flow control device connected between the gas-liquid separation device 12 and the second branch portion 11, and reference numeral 14 denotes a bypass connecting the second branch portion 11 and the first connection pipe 6. A pipe, 15 a fourth flow control device provided in the middle of the bypass pipe 14, 16 a downstream portion of the fourth flow control device 15 of the bypass pipe 14 and a second branch from the third flow control device 13 A second heat exchange section 19 for performing heat exchange with a pipe reaching the meeting section 18A of 11 is a downstream section of the second heat exchange section 16 of the bypass pipe 14, the gas-liquid separation device 12 and the third A first heat exchange unit for exchanging heat with a pipe connecting the flow control device 13 is a valve device control unit for controlling the opening and closing of the first and second valve devices 8 a and 20. Was attached to a pipe connecting the third flow control device 13 and the gas-liquid separation device 12. 1 of the pressure detector, 46 denotes a second pressure detector which is mounted on the pipe connecting the third flow controller 13 and a second branch portion 11.
[0027]
The air conditioner according to the first embodiment configured as described above performs roughly three modes of operation. That is, a case where the cooling operation is performed by all of the plurality of indoor units, a case where the heating operation is performed by all of the plurality of indoor units, a portion of the plurality of indoor units perform the cooling operation, and Is a case where the heating operation is performed (simultaneous cooling and heating operation). Further, two modes of operation are performed for the simultaneous cooling and heating operation. That is, a case in which most of the indoor units among the plurality of indoor units perform the heating operation (heating-main operation), and a case in which most of the plurality of indoor units perform the cooling operation (cooling-main operation). The operation state in each of the above operations will be described below.
[0028]
First, the case of only the cooling operation will be described with reference to FIG. As shown by the solid line arrows in FIG. 2, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, and is condensed by heat exchange in the heat source device side heat exchanger 3. , Through the third check valve 32 and the second connection pipe 7, and flows into the repeater E.
The refrigerant that has flowed into the repeater E flows into the second branch 11 in the order of the gas-liquid separator 12 and the third flow controller 13. The refrigerant that has flowed into the second branch portion 11 branches into the second connection pipes 7b, 7c, and 7d on the indoor unit side at the meeting portion 17A, flows into the indoor units B, C, and D, and flows into each indoor unit B, C, and D. After the pressure is reduced to a low pressure by the first flow control device 9 controlled by the degree of superheat at the outlet of the heat exchanger 5, the indoor heat exchanger 5 exchanges heat with room air to evaporate and gasify, thereby cooling the room. I do. The refrigerant in the gaseous state passes through the first connection pipes 6b, 6c, 6d on the indoor unit side, the first valve device 8a or the second valve device 20 of the first branch portion 10, and the first connection device. Of the compressor 1 through the connection pipe 6, the fourth check valve 33, the four-way switching valve 2, and the accumulator 4, to perform the cooling operation. At this time, the first valve device 8a or the second valve device 20 is open, and the fourth valve device 8b is closed.
[0029]
Further, at this time, the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, so that the refrigerant necessarily flows to the third check valve 32 and the fourth check valve 33. At the time of this cycle, a part of the refrigerant that has passed through the third flow control device 13 enters the bypass pipe 14, is reduced to a low pressure by the fourth flow control device 15, and is reduced by the second heat exchange unit 16. The heat exchange is performed between the refrigerant flowing into the second branch portion 11 of each indoor unit and the heat exchange between the refrigerant flowing into the third flow control device 13 by the first heat exchange portion 19. The refrigerant evaporated after the exchange enters the first connection pipe 6 and is sucked into the compressor 1 through the fourth check valve 33, the four-way switching valve 2, and the accumulator 4. On the other hand, the refrigerant in the second branch portion 11 which has been cooled by heat exchange in the first heat exchange portion 19 and has a sufficient degree of subcooling is connected to the first check valve 17 and the second connection on the indoor side. The air flows into the indoor units B, C, and D to be cooled via the pipes 7b, 7c, and 7d.
[0030]
When the evaporation temperature of any of the indoor heat exchangers 5 of the indoor units B, C, and D to be cooled is increased, the valve device control unit 21 activates the first valve device 8a corresponding to the indoor unit. When performing control to close and open the second valve device 20 to reduce the evaporation temperature of any of the indoor heat exchangers 5 of the indoor units B, C, and D to be cooled to a normal temperature or a low temperature. Performs control to open the first valve device 8a corresponding to the indoor unit and close the second valve device 20. That is, when the first valve device 8a is opened and the second valve device 20 is closed, the refrigerant flows without passing through the capillary tube 22, so that the pressure loss is small and the evaporation temperature of the indoor heat exchanger 5 is reduced. Normal temperature or lower.
On the other hand, when the first valve device 8a is closed and the second valve device 20 is opened, the refrigerant flows through the capillary tube 22 so that the pressure loss is large and the evaporation temperature of the indoor heat exchanger 5 is reduced. It becomes possible to raise it. In this manner, the evaporation temperature of each indoor unit side heat exchanger 5 can be selectively increased.
[0031]
Further, when a compressor whose capacity is variable by an inverter control or the like is used as the compressor 1, the evaporating temperature in the indoor heat exchanger 5 can be finely set to an arbitrary temperature by changing the operating capacity of the compressor. It becomes possible to control. That is, when increasing the evaporation temperature in the indoor heat exchanger 5, control is performed to reduce the operating capacity of the compressor 1, and conversely, when decreasing the evaporation temperature in the indoor heat exchanger 5, the compressor is controlled. Control is performed so as to increase the operation capacity of No. 1.
[0032]
Here, the relationship between the evaporation temperature of the indoor heat exchanger and the sensible heat capacity during the cooling operation will be described with reference to FIG. FIG. 5 shows the evaporation temperature during cooling operation under certain air conditions (constant dry-bulb temperature and wet-bulb temperature) when using a general indoor heat exchanger, and the cooling capacity (latent heat capacity and sensible heat capacity). ), Sensible heat capacity, sensible heat ratio (ratio of sensible heat capacity to cooling capacity), the horizontal axis is the evaporation temperature, the left vertical axis is the cooling capacity and sensible heat capacity, the right vertical axis is the sensible heat capacity. It shows a heat ratio. As shown in FIG. 5, as the evaporating temperature increases, the cooling capacity decreases, but the sensible heat capacity remains almost constant. That is, the sensible heat ratio increases as the evaporation temperature increases.
[0033]
Therefore, when the capacity of the indoor unit is selected so as to match the sensible heat load in a place where the sensible heat load is large, such as in a computer room, it is better to select when the normal evaporation temperature or the evaporation temperature is low. It is necessary to select an indoor unit with a large cooling capacity, that is, an indoor unit with a large product shape, but since the sensible heat ratio is increased by increasing the evaporation temperature, an indoor unit with a small cooling capacity, that is, a product shape However, it is possible to select an indoor unit having a small size, and cost can be reduced. In addition, if an attempt is made to obtain the required sensible heat capacity using an indoor unit having a large cooling capacity, the cooling capacity becomes large. There is a possibility that a problem that causes water leakage due to freezing may occur, but this problem can be prevented by increasing the evaporation temperature.
In addition, when a compressor with a variable capacity, such as by inverter control, is used as the compressor, the operating capacity of the compressor can be reduced to increase the evaporating temperature, so that power consumption can be reduced and energy savings can be obtained. Becomes possible.
[0034]
In the first embodiment described above, the refrigerating cycle connected with the relay unit has been described. However, in the refrigerating cycle including only the heat source unit and the indoor unit, the evaporation temperature can be increased by using the variable capacity compressor. And the same effect can be obtained.
[0035]
Next, a case of only the heating operation will be described with reference to FIG. In this case, the four-way switching valve 2 is switched, and the flow of the refrigerant is as shown by the broken arrow in FIG. That is, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 flows through the four-way switching valve 2, the fifth check valve 34 and the second connection pipe 7, and flows into the relay E. The refrigerant flowing into the repeater E flows into the first branch 10 via the gas-liquid separator 12 and the second connection pipe 7. The refrigerant flowing into the first branch portion 10 passes through the fourth valve device 8b and the first connection pipes 6b, 6c, and 6d on the indoor unit side, flows into the indoor units B, C, and D, and flows into the indoor side. The heat exchanger 5 exchanges heat with room air to condense and liquefy, and heats the room. Then, the refrigerant in a liquid state passes through the first flow control device 9 controlled by the degree of supercooling at the outlet of each indoor heat exchanger 5, and passes through the second connection pipes 7b, 7c, 7d, flows into the second branch portion 11, passes through the second check valve 18, merges at the meeting portion 18A, flows into the fourth flow control device 15, and flows into the low-pressure gas-liquid two-phase. The pressure is reduced to the state. The refrigerant decompressed to a low pressure passes through the bypass pipe 14, the second heat exchange section 16, the first heat exchange section 19, and then passes through the first connection pipe 6, and passes through the sixth check valve 35, the heat source device. The refrigerant that has flowed into the side heat exchanger 3 and exchanged heat to evaporate into a gaseous state forms a circulation cycle that is sucked into the compressor 1 through the four-way switching valve 2 and the accumulator 4, and performs a heating operation.
At this time, the first and second valve devices 8a and 20 are closed, and the fourth valve device 8b is open. In addition, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, the refrigerant necessarily flows to the fifth check valve 34 and the sixth check valve 35.
[0036]
Next, a case of mainly heating in the simultaneous cooling and heating operation will be described with reference to FIG. Here, a case will be described in which two of the indoor units B and C are going to heat and one of the indoor units D is going to cool. That is, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, the fifth check valve 34, and the second connection pipe 7 as shown by a solid line arrow in FIG. Inflow. The refrigerant that has flowed into the repeater E flows into the first branch portion 10 via the gas-liquid separator 12. The refrigerant flowing into the first branch portion 10 passes through the fourth valve device 8b connected to the indoor units B and C, and the first connection pipes 6b and 6c on the indoor unit side in this order, and the indoor unit to be heated is heated. It flows into B and C and exchanges heat with the indoor air in the indoor heat exchanger 5 to condense and liquefy and heat the room. The refrigerant in the liquid state is controlled by the degree of supercooling at the outlet of the indoor side heat exchanger 5, passes through the first flow control device 9 which is almost fully opened, and is slightly depressurized to a pressure between the high pressure and the low pressure. It becomes pressure (intermediate pressure), and joins from the second connection pipes 7b and 7c on the indoor unit side through the second check valve 18 at the meeting portion 18A.
[0037]
The flow of the refrigerant to the indoor unit D to be cooled is such that a part of the refrigerant joined at the meeting part 18A of the second branch part 11 of the repeater E passes through the second heat exchange part 16 to the second branch part. 11 and passes through the first check valve 17 connected to the indoor unit D and the second connection pipe 7d on the indoor side, enters the indoor side heat exchanger 5 and exchanges heat to evaporate the gas. In this state, the room is cooled, and flows into the first connection pipe 6 via the first valve device 8a or the second valve device 20 connected to the indoor unit D of the first branch portion 10.
On the other hand, another part of the refrigerant for heating the indoor units B and C that has flowed from the indoor units B and C into the meeting part 18A of the second branch part 11 of the relay unit E is a high-pressure refrigerant in the second connection pipe 7. Through the openable and closable fourth flow control device 15, which is controlled to make the difference between the pressure and the intermediate pressure of the second branch portion 11 constant, flows into the bypass pipe 14, and flows into the first connection pipe 6. At this point, the indoor unit D joins the cooled refrigerant and flows into the thick first connection pipe 6, flows into the sixth check valve 35, the heat source unit side heat exchanger 3, exchanges heat, and evaporates. The refrigerant in the gaseous state passes through the four-way switching valve 2 and the accumulator 4 to be drawn into the compressor 1 to form a circulation cycle, and performs a heating-main operation.
[0038]
At this time, the first and second valve devices 8a and 20 connected to the indoor units B and C to be heated are closed, and the fourth valve device 8b is opened to be connected to the indoor unit D to be cooled. The first valve device 8a or the second valve device 20 is open, and the fourth valve device 8b is closed. In addition, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, the refrigerant necessarily flows to the fifth check valve 34 and the sixth check valve 35.
[0039]
At the time of this cycle, the refrigerant flowing into the bypass pipe 14 is decompressed to a low pressure by the fourth flow control device 15, and mixed with the refrigerant flowing into the second branch 11 in the second heat exchange unit 16. In the meantime, the refrigerant that has exchanged heat with the refrigerant flowing into the third flow control device 13 in the first heat exchange unit 19 and evaporates enters the first connection pipe 6 and is subjected to the sixth check. After passing through the valve 35, it flows into the heat source device side heat exchanger 3 and exchanges heat to evaporate to a gas state. Then, the refrigerant is sucked into the compressor 1 through the four-way switching valve 2 and the accumulator 4. On the other hand, the refrigerant that has undergone heat exchange in the first and second heat exchange units 19 and 16 and has been cooled and has a sufficient degree of supercooling flows into the indoor unit D to be cooled.
[0040]
In the heating-main operation, the valve device control unit 21 closes the first valve device 8a corresponding to the indoor unit D when the evaporation temperature of the indoor heat exchanger 5 of the indoor unit D to be cooled is increased. When the control to open the second valve device 20 is performed to reduce the evaporation temperature of the indoor heat exchanger 5 of the indoor unit D to be cooled to a normal temperature or a low temperature, this corresponds to the indoor unit. Control is performed to open the first valve device 8a and close the second valve device 20. That is, when the first valve device 8a is opened and the second valve device 20 is closed, the refrigerant flows without passing through the capillary tube 22, so that the pressure loss is small and the evaporation temperature of the indoor heat exchanger 5 is reduced. Normal temperature or lower. On the other hand, when the first valve device 8a is closed and the second valve device 20 is opened, the refrigerant flows through the capillary tube 22 so that the pressure loss is large and the evaporation temperature of the indoor heat exchanger 5 is reduced. It becomes possible to raise it. Thus, it is possible to selectively increase the evaporation temperature of each indoor side heat exchanger 5.
Since the effect of selectively controlling the evaporation temperature of the indoor unit D to be cooled is the same as the effect at the time of the cooling operation described above, the description is omitted here.
[0041]
Next, a case where cooling is mainly performed in simultaneous cooling and heating operation will be described with reference to FIG. Here, a case will be described in which two of the indoor units B and C are to be cooled, and one of the indoor units D is to be heated. That is, as shown by a solid line arrow in FIG. 4, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2 and exchanges an arbitrary amount of heat in the heat source device side heat exchanger 3. It becomes a gas-liquid two-phase high-temperature and high-pressure refrigerant, and flows into the repeater E through the third check valve 32 and the second connection pipe 7. The refrigerant flowing into the repeater E is sent to the gas-liquid separator 12 where it is separated into a gaseous refrigerant and a liquid refrigerant. The separated gaseous refrigerant passes through the second connection pipe 7 to the first refrigerant of the repeater E. Flows into the indoor unit D to be heated in the order of the fourth valve device 8b of the branch portion 10 and the first connection pipe 6d on the indoor unit side, and exchanges heat with the indoor air in the indoor heat exchanger 5. To condense and liquefy and heat the room.
[0042]
Further, the pressure is controlled by the degree of supercooling at the outlet of the indoor side heat exchanger 5 and slightly reduced through the first flow control device 9 which is almost fully opened, and becomes an intermediate pressure between the high pressure and the low pressure (intermediate pressure). Through the second connection pipe 7d, through the second check valve 18 of the second branch portion 11 and into the bypass pipe 14 from the meeting portion 18A, and is reduced to a low pressure by the fourth flow control device 15. The second heat exchanger 16 exchanges heat with the refrigerant flowing into the second branch 11, and the first heat exchanger 19 exchanges heat with the refrigerant flowing into the third flow controller 13. The refrigerant that has undergone heat exchange between and evaporates reaches the first connection pipe 6.
On the other hand, the remaining liquid refrigerant separated by the gas-liquid separation device 12 of the repeater E is cooled by exchanging heat in the first heat exchange unit 19 and has a sufficient degree of supercooling. Through the third flow control device 13 which is controlled so as to keep the flow rate constant.
[0043]
The flow of the refrigerant to the indoor units B and C to be cooled depends on the first check valve 17 connected to the indoor units B and C from the junction 17A of the second branch unit 11 of the repeater E and the indoor unit. Flows into the indoor units B and C through the second connection pipes 7b and 7c on the side. Then, the refrigerant is reduced to a low pressure by the first flow control device 9 controlled by the degree of superheat at the outlet of the indoor heat exchanger 5 of the indoor units B and C, and the indoor heat exchanger 5 is connected to the indoor air. It is evaporated and gasified by heat exchange to cool the room. Then, the refrigerant in the gas state passes through the first connection pipes 6b and 6c on the indoor unit side, the first valve device 8a or the second valve device 20 of the first branch portion 10, and then passes through the first valve. After flowing into the connection pipe 6 and flowing into the first connection pipe 6 via the bypass pipe 14 and joining with the above-mentioned heating refrigerant of the indoor unit D, the fourth check valve 33, the four-way switching valve 2, the accumulator 4 Constitute a circulation cycle in which the refrigerant is sucked into the compressor 1 through the above, and the cooling-main operation is performed.
[0044]
At this time, the first valve device 8a or the second valve device 20 connected to the indoor units B and C to be cooled is open, the fourth valve device 8b is closed, and the indoor unit D to be heated is closed. The connected first and second valve devices 8a and 20 are closed, and the fourth valve device 8b is open. Further, since the first connection pipe 6 has a low pressure and the second connection pipe 7 has a high pressure, the refrigerant necessarily flows to the third check valve 32 and the fourth check valve 33.
[0045]
In the cooling-main operation, when the evaporating temperature of any one of the indoor heat exchangers 5 of the indoor units B and C to be cooled is increased by the valve device control unit 21, the first unit corresponding to the indoor unit is used. Control is performed to close the valve device 8a and open the second valve device 20 to lower the evaporation temperature of one of the indoor heat exchangers 5 of the indoor units B and C to be cooled to a normal temperature or a lower temperature. In such a case, control is performed to open the first valve device 8a corresponding to the indoor unit and close the second valve device 20. That is, when the first valve device 8a is opened and the second valve device 20 is closed, the refrigerant flows without passing through the capillary tube 22, so that the pressure loss is small and the evaporation temperature of the indoor heat exchanger 5 is reduced. Normal temperature or lower. On the other hand, when the first valve device 8a is closed and the second valve device 20 is opened, the refrigerant flows through the capillary tube 22 so that the pressure loss is large and the evaporation temperature of the indoor heat exchanger 5 is reduced. It becomes possible to raise it. Thus, it is possible to selectively increase the evaporation temperature of each indoor side heat exchanger 5.
The effect of selectively controlling the evaporation temperatures of the indoor units B and C to be cooled is the same as the effect at the time of the cooling operation described above, and the description is omitted here.
[0046]
Embodiment 2 FIG.
Next, a second embodiment of the present invention will be described in detail with reference to FIG.
FIG. 6 is a refrigerant circuit diagram illustrating the overall configuration of the second embodiment. In this figure, the same or corresponding parts as those in FIG. In FIG. 6, three second terminals 23 are connected at one end to the first connection pipes 6 b, 6 c, and 6 d on the indoor unit side, respectively, and the other ends are collectively connected and connected to the first connection pipe 6. This is a second flow control device interposed between the valve device 20 and the first connection pipes 6b, 6c, 6d, and from the first connection pipes 6b, 6c, 6d to the first connection pipe 6 during cooling operation. Controls the pressure loss of the flowing refrigerant.
Reference numeral 24 denotes a flow controller control unit for controlling the valve opening of the second flow controller 23, which can control the evaporation temperature in the indoor heat exchanger to be arbitrarily high during the cooling operation.
Further, the flow of the refrigerant during the cooling operation, the heating operation, and the simultaneous cooling / heating operation (cooling-main operation and heating-main operation) is the same as that in the first embodiment described above, and thus the description is omitted.
[0047]
Here, the valve device control unit 21 and the flow control device control unit 24 during the cooling operation in the second embodiment will be described.
When the evaporation temperature of any of the indoor heat exchangers 5 of the indoor units B, C, and D to be cooled is increased, the valve device control unit 21 activates the first valve device 8a corresponding to the indoor unit. When performing control to close and open the second valve device 20 to reduce the evaporation temperature of any of the indoor heat exchangers 5 of the indoor units B, C, and D to be cooled to a normal temperature or a low temperature. Performs control to open the first valve device 8a corresponding to the indoor unit and close the second valve device 20. That is, when the first valve device 8a is opened and the second valve device 20 is closed, the refrigerant flows without passing through the second flow control device 23, so that the pressure loss is small and the indoor heat exchanger The evaporation temperature of 5 can be normal or low. On the other hand, when the first valve device 8a is closed and the second valve device 20 is opened, the refrigerant flows through the second flow control device 23, so that the pressure loss is large and the indoor heat exchanger is large. 5 can be increased.
[0048]
At this time, by controlling the valve opening of the second flow control device 23 arbitrarily by the flow control device control unit 24, the pressure loss when the refrigerant flows through the second flow control device 23 can be arbitrarily set. , It is possible to selectively and elevate the evaporation temperature of each indoor heat exchanger 5 to an arbitrary temperature. Further, even when a part of the indoor units B, C, and D is used in a place having a large sensible heat load such as a computer room such as a building, the evaporation temperature is increased to an arbitrary temperature by using the ordinary indoor unit as it is. Since the operation with a large sensible heat ratio can be performed by controlling, the required sensible heat capacity can be set to any desired temperature, and the cost can be reduced.
[0049]
Further, when a compressor whose capacity is variable by an inverter control or the like is used as the compressor 1, a combination of control by varying the operating capacity of the compressor and valve opening degree control of the second flow control device 23 provides: The setting of the evaporation temperature in the indoor heat exchanger 5 can be finely controlled to an arbitrary temperature in accordance with the usage environment of each indoor unit, and the operation for reducing power consumption can be automatically performed. That is, when increasing the evaporation temperature of all of the indoor units B, C, and D, control is performed to reduce the operating capacity of the compressor 1 to reduce power consumption and give priority to energy saving operation. If part of the unit is used in a place with normal air conditioning load and normal cooling capacity is required, and other indoor units are used in places with large sensible heat capacity such as computer rooms and want to set a large sensible heat ratio, That is, when it is desired to set the evaporating temperature high, the evaporating temperature is controlled only by controlling the valve opening degree of the second flow control device 23, so that the cooling of the indoor unit used under the normal air conditioning load is performed. Operation can be performed without reducing capacity. Thus, even if the use environment of each indoor unit is different, it is possible to automatically switch between the evaporating temperature control and the energy saving operation.
[0050]
【The invention's effect】
In the air conditioner according to the present invention, even when a part of the indoor unit is used in a place having a large sensible heat load such as a computer room such as a building, the evaporation temperature is controlled to be high using the normal indoor unit as it is. As a result, the operation having a large sensible heat ratio can be performed, so that the required sensible heat capacity can be obtained at low cost.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an air-conditioning apparatus according to Embodiment 1 of the present invention.
FIG. 2 is an operation state diagram of only cooling or heating of the air-conditioning apparatus shown in FIG.
FIG. 3 is a diagram showing an operation state of the air conditioning apparatus shown in FIG. 1 mainly for heating.
FIG. 4 is an operation state diagram mainly showing cooling of the air-conditioning apparatus shown in FIG. 1;
FIG. 5 is a diagram showing the relationship between the evaporation temperature of the indoor heat exchanger and the sensible heat capacity during the cooling operation.
FIG. 6 is an overall configuration diagram of an air-conditioning apparatus according to Embodiment 2 of the present invention.
FIG. 7 is an overall configuration diagram of a conventional air conditioner.
8 is an operation state diagram of only the cooling or heating of the air-conditioning apparatus shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor, 2 four-way switching valve, 3 heat source unit side heat exchanger, 4 accumulator, 5 indoor side heat exchanger, 6 first connection piping, 6b, 6c, 6d 1st connection piping on indoor unit side, 7 Second connection pipe, 7b, 7c, 7d Second connection pipe on the indoor unit side, 8a first valve device, 8b fourth valve device, 9 first flow control device, 10 first branching section, DESCRIPTION OF SYMBOLS 11 2nd branch part, 12 gas-liquid separation apparatus, 13 3rd flow control apparatus, 14 bypass piping, 15 4th flow control apparatus, 16 2nd heat exchange part, 17 1st check valve, 17A , 18A association unit, 18 second check valve, 19 first heat exchange unit, 20 second valve unit, 21 valve unit control unit, 22 capillary tube, 23 second flow control unit, 24 flow control unit control Part, 25 third heat exchange part, 26 first temperature detector, 27 second temperature detector, 32 third Check valve, 33 fourth check valve, 34 fifth check valve, 35 sixth check valve, 45 first pressure detector, 46 second pressure detector, A heat source unit, B, C, D indoor unit, E repeater.

Claims

A heat source unit having a compressor, a four-way switching valve for switching a flow path of a refrigerant discharged from the compressor, and a heat source device side heat exchanger connected to the four-way switching valve, an indoor heat exchanger And a plurality of indoor units each having a flow control device connected thereto, and the heat source unit and each indoor unit are connected via first and second connection pipes, and each of the indoor heat exchangers is connected. Is connected to the first and second connection pipes so as to be switchable, and one end of each indoor heat exchanger is switchably connected to the first connection pipe via a capillary tube. A first branch having a valve device to be connected, and a repeater including a second branch capable of connecting the other end of each indoor heat exchanger to the second connection pipe. And air conditioners.

At the time of cooling operation, one end of each indoor heat exchanger is connected to the first connection pipe via a capillary, and one end of each indoor heat exchanger is connected to the first end without the capillary. 2. The air conditioner according to claim 1, further comprising a valve device control unit configured to control selection of connection to one connection pipe for each indoor unit.

A heat source unit having a compressor, a four-way switching valve for switching a flow path of a refrigerant discharged from the compressor, and a heat source device side heat exchanger connected to the four-way switching valve, an indoor heat exchanger And a plurality of indoor units each having a flow control device connected thereto, and the heat source unit and each indoor unit are connected via first and second connection pipes, and each of the indoor heat exchangers is connected. Is connected to the first and second connection pipes in a switchable manner, and one end of each indoor heat exchanger is switchable to the first connection pipe via a flow control device. A first branch portion having a valve device connected to the second heat exchanger and a second branch portion capable of connecting the other end of each of the indoor heat exchangers to the second connection pipe. An air conditioner characterized by the above-mentioned.

During cooling operation, one end of each indoor heat exchanger is connected to the first connection pipe via a flow control device, and one end of each indoor heat exchanger is connected via a flow control device. 4. The air conditioner according to claim 3, further comprising a valve device control unit configured to control the selection of whether to connect to the first connection pipe for each indoor unit.

The air conditioner according to any one of claims 1 to 4, wherein the compressor uses a variable capacity compressor.

The valve device at the first branch has two or more valves connected in parallel to one end of each indoor heat exchanger, and one valve is connected to the first connection pipe. The air conditioner according to any one of claims 1 to 5, wherein the other valve is connected to a second connection pipe.