JP2004309088A - Refrigerating or air-conditioning system and its replacement method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating or air-conditioning system and its replacement method diverting existing refrigerant piping to shorten a construction period of replacement work and to reduce a replacement cost and reducing a pressure loss in refrigerant piping to improve the efficiency of the system while being useful for global environment protection. <P>SOLUTION: This refrigerating or air-conditioning system is provided with a heat source machine A having a compressor 1, a four-way selector valve 2 and a heat source side heat exchanger 3; indoor units B, C having load side heat exchangers 11b, 11c and flow control devices 12b, 12c; and a flow dividing controller D connecting the heat source machine A and the indoor units B, C through first and second connection piping 6, 7 and having a valve device 13 for connecting one end part of load side heat exchangers 11b, 11c selectively to the first and second connection piping 6, 7. The first and second connection piping 6, 7 are formed of the existing connection piping for an old refrigerant, and at least one of the heat source machine and indoor units is formed of a replacing machine for a new refrigerant higher in operating pressure than the old refrigerant. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００７】
一方、冷媒にＲ２２やＲ４０７Ｃを使用するビル用マルチエアコンでは、表２に示すように高圧の設計圧力はガス管の許容圧力に近いため、熱源機と室内機を更新する場合には、更新後の熱源機と室内機が、更新前の熱源機と室内機の動作圧力に近い冷媒を用いるものに限られていた。
【表２】

既設の冷凍または空気調和装置の動作圧力よりも高い動作圧力の冷媒（例えばＲ４１０Ａ）を用いるシステムへの更新では、既設の冷媒配管が使用できないため工期が長くなり、また、コストも大きくなるという問題点があった。
更に、年々、省エネ性への要求が高まる中、機器に使用される要素の性能改善だけでは、これらの要求を満足することができず、また、機器のコスト耐力が低下するなどの問題点があった。
【０００８】
この発明は、上記のような問題点を解消するためになされたもので、既設冷媒配管を流用して更新工事の工期を短縮し、更新コストを低減すると共に、冷媒配管での圧力損失を低減して装置の効率を改善し、地球環境保護にも役立つ冷凍または空気調和装置及びその更新方法を提供することを目的とする。
【０００９】
【課題を解決するための手段】
この発明に係る冷凍または空気調和装置は、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側熱交換器とを有する熱源機、負荷側熱交換器と、これに接続された流量制御装置とを有する室内機、及び上記熱源機と室内機とを第１及び第２の接続配管を介して接続すると共に、上記負荷側熱交換器の一方の端部を上記第１及び第２の接続配管に切り換え可能に接続する弁装置を有する分流コントローラを備えた冷凍または空気調和装置において、上記第１および第２の接続配管を旧冷媒用の既設の接続配管とし、上記熱源機及び室内機の少なくとも一方を上記旧冷媒より動作圧力が高い新冷媒用の更新機としたことを特徴とするものである。
【００１０】
【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を図にもとづいて説明する。図１は、実施の形態１による冷凍または空気調和装置の構成を示す冷媒回路図で、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の例を示しており、各室内機毎に冷暖房を選択的に行なうことができ、冷房を行なう室内機と、暖房を行なう室内機とを同時に運転することができる例を示している。なお、図１では熱源機１台に室内機２台、分流コントローラ１台を接続した場合について説明するが、３台以上の室内機、及び２台以上の分流コントローラを接続した場合でも同様に実施できることは云うまでもない。
【００１１】
図１において、Ａは熱源機、Ｂ、Ｃ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されている。Ｄは熱源機Ａと室内機Ｂ、Ｃとを接続する分流コントローラで、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、圧縮機１と、この圧縮機１に接続され、冷媒の流通方向を切り換える四方切換弁２と、熱源側熱交換器３と、四方切換弁２及び圧縮機１の間に接続されたアキュムレータ４と、熱源側熱交換器３及び後述する第１の接続配管６の間に設けられ、熱源側熱交換器３から第１の接続配管６の方向へのみ冷媒流通を許容する第１の逆止弁５ａと、四方切換弁２及び後述する第２の接続配管７の間に設けられ、第２の接続配管７から四方切換弁２の方向へのみ冷媒流通を許容する第２の逆止弁５ｂと、四方切換弁２及び第１の接続配管６の間に設けられ、四方切換弁２から第１の接続配管６の方向へのみ冷媒流通を許容する第３の逆止弁５ｃと、熱源側熱交換器３及び第２の接続配管７の間に設けられ、第２の接続配管７から熱源側熱交換器３の方向へのみ冷媒流通を許容する第４の逆止弁５ｄとから構成されている。
【００１２】
また、室内機Ｂ、Ｃは、それぞれ負荷側熱交換器１１ｂ、１１ｃと、各負荷側熱交換器１１ｂ、１１ｃに直列接続された絞り装置等の流量制御装置１２ｂ、１２ｃとで構成されている。なお、各流量制御装置１２ｂ、１２ｃは、冷房時は負荷側熱交換器１１ｂ、１１ｃの出口側の過熱度により、暖房時は同じく出口側の過冷却度により開閉状態が制御されるようにされている。更に、分流コントローラＤは四方切換弁２と接続された太い第２の接続配管７及び熱源側熱交換器３と接続され、第２の接続配管７より細い第１の接続配管６によって熱源機Ａと接続され、室内機Ｂ、Ｃの負荷側熱交換器１１ｂ、１１ｃと接続された負荷側の第２の接続配管７ｂ、７ｃ及び室内機Ｂ、Ｃの流量制御装置１２ｂ、１２ｃに接続された負荷側の第１の接続配管６ｂ、６ｃによって各室内機Ｂ、Ｃ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。
【００１３】
即ち、１３は負荷側の第２の接続配管７ｂ、７ｃを、第１の接続配管６または第２の接続配管７に切り換え可能に接続する弁装置で、一端が負荷側の第２の接続配管７ｂ、７ｃ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２個の第１の弁装置１３ａと、一端が負荷側の第２の接続配管７ｂ、７ｃ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２個の第２の弁装置１３ｂとから構成され、第１の弁装置１３ａを開路、第２の弁装置１３ｂを閉路することにより、負荷側の第２の接続配管７ｂ、７ｃを第１の接続配管６に接続し、また、第１の弁装置１３ａを閉路、第２の弁装置１３ｂを開路することにより、負荷側の第２の接続配管７ｂ、７ｃを第２の接続配管７に接続するものである。
【００１４】
また、第１の接続配管６の途中に気液分離器１４が設けられ、その気相部が、第１の接続配管６の後半部を経て第１の弁装置１３ａに接続され、その液相部が第１の熱交換部１５、開閉自在な第２の流量制御装置１６及び第２の熱交換部１７を介して負荷側の第１の接続配管６ｂ、６ｃに接続されている。また、バイパス配管１８に設けられた第３の流量制御装置１９を経て気液分離器１４からの液冷媒の一部が第２の熱交換部１７及び第１の熱交換部１５で熱交換し、気液分離器１４からの液冷媒を過冷却して第２の接続配管７に戻るようにされている。
【００１５】
このように構成された実施の形態１の冷凍または空気調和装置によって、上述したように大きく分けて３つの形態の運転が行なわれる。即ち、複数の室内機の総てで冷房運転を行なう場合と、複数の室内機の総てで暖房運転を行なう場合と、複数の室内機のうち一部は冷房運転を行ない、他の一部は暖房運転を行なう場合（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なわれる。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なう場合（暖房主体運転）と、複数の室内機のうち大部分の室内機が冷房運転を行なう場合（冷房主体運転）とである。
【００１６】
まず、図２を用いて総ての室内機を冷房運転する全冷房運転について説明する。即ち、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、熱源側熱交換器３で熱交換して凝縮された後、第１の逆止弁５ａ、第１の接続配管６を通り、分流コントローラＤへ流入する。分流コントローラＤへ流入した冷媒は気液分離器１４、第２の流量制御装置１６の順に通り、負荷側の第１の接続配管６ｂ、６ｃを通り、各室内機Ｂ、Ｃに流入し、各負荷側熱交換器１１ｂ、１１ｃの出口の過熱度により制御される流量制御装置１２ｂ、１２ｃにより低圧まで減圧されて負荷側熱交換器１１ｂ、１１ｃ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、負荷側の第２の接続配管７ｂ、７ｃ、第２の弁装置１３ｂを通り、第２の接続配管７、第２の逆止弁５ｂ、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、冷房運転を行なう。この時、第１の弁装置１３ａは閉路、第２の弁装置１３ｂは開路されている。
【００１７】
また、第２の接続配管７は低圧、第１の接続配管６は高圧のため必然的に第１の逆止弁５ａ、第２の逆止弁５ｂへ冷媒が流通する。
更に、このサイクルの時、第２の流量制御装置１６を通過した冷媒の一部が第２の熱交換部１７及び第３の流量制御装置１９を経てバイパス配管１８へ入り、第３の流量制御装置１９で低圧まで減圧されて、第２の熱交換部１７で負荷側の第１の接続配管６ｂ、６ｃに流入する冷媒との間で熱交換を行ない、また、第１の熱交換部１５で第２の流量制御装置１６に流入する冷媒との間で熱交換を行ない蒸発した冷媒は、第２の接続配管７へ入り、第２の逆止弁５ｂ、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１５で熱交換し、過冷却度が増大された冷媒は、負荷側の第１の接続配管６ｂ、６ｃを経由して冷房しようとしている室内機Ｂ、Ｃへ流入する。
【００１８】
次に、図３を用いて総ての室内機を暖房運転する全暖房運転について説明する。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３に実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３の逆止弁５ｃ、第１の接続配管６を通り、分流コントローラＤへ流入する。分流コントローラＤへ流入した冷媒は気液分離器１４、第１の接続配管６の後半部を経て第１の弁装置１３ａ、負荷側の第２の接続配管７ｂ、７ｃを通り、各室内機Ｂ、Ｃに流入し、室内空気と熱交換して凝縮液化し、室内を暖房する。
【００１９】
そして、液状態となった冷媒は、各負荷側熱交換器１１ｂ、１１ｃの出口の過冷却度により制御される流量制御装置１２ｂ、１２ｃを通り、負荷側の第１の接続配管６ｂ、６ｃからバイパス配管１８の第３の流量制御装置１９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、第２の熱交換部１７、第１の熱交換部１５を経た後、第２の接続配管７を通り、第４の逆止弁５ｄ、熱源側熱交換器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、暖房運転を行なう。この時、第１の弁装置１３ａは開路、第２の弁装置１３ｂは閉路されている。また、第２の接続配管７は低圧、第１の接続配管６は高圧のため必然的に第３の逆止弁５ｃ、第４の逆止弁５ｄへ冷媒が流通する。
【００２０】
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４を用いて説明する。ここでは、室内機Ｂが暖房、室内機Ｄが冷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、第３の逆止弁５ｃ、第１の接続配管６を通り、分流コントローラＤに流入する。分流コントローラＤに流入した冷媒は気液分離器１４、第１の接続配管６の後半部を経て第１の弁装置１３ａ、負荷側の第２の接続配管７ｂの順に通り、暖房しようとしている室内機Ｂに流入し、負荷側熱交換器１１ｂ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、負荷側熱交換器１１ｂの出口の過冷却度により制御され、ほぼ全開状態の流量制御装置１２ｂ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、負荷側の第１の接続配管６ｂに流入した冷媒の一部が矢印Ｒのように第２の熱交換部１７を経て冷房しようとしている室内機Ｃに接続された負荷側の第１の接続配管６ｃを通り、負荷側熱交換器１１ｃの出口の過熱度により制御される流量制御装置１２ｃにより減圧された後に室内機Ｃの負荷側熱交換器１１ｃ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、室内機Ｃに接続された第２の弁装置１３ｂを介して第２の接続配管７に流入する。
【００２１】
一方、室内機Ｂから分流コントローラＤの第２の熱交換部１７に流入した室内機Ｂの暖房用の冷媒の他の一部は、バイパス配管１８を経て第１の接続配管６の高圧と流量制御装置１２ｂの出口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３の流量制御装置１９を通って上述のように第２の接続配管７に至るため、ここで室内機Ｃを冷房した冷媒と合流して太い第２の接続配管７に流入し、第４の逆止弁５ｄ、熱源側熱交換器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、暖房主体運転を行なう。
【００２２】
この時、暖房しようとしている室内機Ｂに接続されている第１の弁装置１３ａは開路、第２の弁装置１３ｂは閉路され、冷房しようとしている室内機Ｃに接続されている第１の弁装置１３ａは閉路、第２の弁装置１３ｂは開路されている。
また、第２の接続配管７は低圧、第１の接続配管６は高圧のため必然的に第３の逆止弁５ｃ、第４の逆止弁５ｄへ冷媒が流通する。
【００２３】
また、このサイクルの時、バイパス配管１８へ入った冷媒は、第３の流量制御装置１９で低圧まで減圧されて、第２の熱交換部１７で負荷側の第１の接続配管６ｃへ流入する冷媒との間で熱交換を行ない、更に第１の熱交換部１５で第２の流量制御装置１６へ流入する冷媒との間で熱交換を行ない蒸発した冷媒は、第２の接続配管７へ入り、第４の逆止弁５ｄを経て、熱源側熱交換器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２の熱交換部１７で熱交換し過冷却度が増大された冷媒は、上述のように、冷房しようとしている室内機Ｃへ流入する。
【００２４】
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５を用いて説明する。ここでは、室内機Ｂが暖房、室内機Ｃが冷房しようとしている場合について説明する。即ち、図５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１の逆止弁５ａ、第１の接続配管６を通り、分流コントローラＤに流入する。分流コントローラＤに流入した冷媒は気液分離器１４へ送られ、ここで、ガス冷媒と液冷媒に分離される。分離されたガス冷媒は、第１の接続配管６の後半部を経て分流コントローラＤの弁装置１３の第１の弁装置１３ａ、負荷側の第２の接続配管７ｂの順に通り、暖房しようとしている室内機Ｂに流入し、負荷側熱交換器１１ｂで室内空気と熱交換して凝縮液化し、室内を暖房する。
【００２５】
更に、負荷側熱交換器１１ｂの出口の過冷却度により制御されほぼ全開状態の流量制御装置１２ｂ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、負荷側の第１の接続配管６ｂを経てバイパス配管１８に流入し、第３の流量制御装置１９で低圧まで減圧されて、第２の熱交換部１７で負荷側の第１の接続配管６ｃに流入する冷媒との間で熱交換を行ない、また、第１の熱交換部１５で第２の流量制御装置１６へ流入する冷媒との間で熱交換を行ない蒸発した冷媒は、第２の接続配管７に至る。一方、分流コントローラＤの気液分離器１４で分離された残りの液冷媒は、第１の熱交換部１５で熱交換して過冷却度が増大された後、高圧と中間圧の差を一定にするように制御される第２の流量制御装置１６を通って矢印で示すように、負荷側の第１の接続配管６ｃを通り、室内機Ｃに流入する。そして、この冷媒は、室内機Ｃの負荷側熱交換器１１ｃの出口の過熱度により制御される流量制御装置１２ｃにより低圧まで減圧されて負荷側熱交換器１１ｃ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、負荷側の第２の接続配管７ｃ、第２の弁装置１３ｂを経て第２の接続配管７へ流入し、バイパス配管１８を経て第２の接続配管７に流入する上述の室内機Ｂの暖房用冷媒と合流した後、第２の逆止弁５ｂ、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、冷房主体運転を行なう。
【００２６】
この時、冷房しようとしている室内機Ｃに接続されている第１の弁装置１３ａは閉路、第２の弁装置１３ｂは開路され、暖房しようとしている室内機Ｂに接続されている第１の弁装置１３ａは開路、第２の弁装置１３ｂは閉路されている。また、第２の接続配管７は低圧、第１の接続配管６は高圧のため必然的に第１の逆止弁５ａ、第２の逆止弁５ｂへ冷媒が流通する。
【００２７】
この実施の形態による冷凍または空気調和装置は、以上のように構成されているため、液冷媒が流通する冷媒配管である第１の接続配管６は常に高圧で使用され、ガス冷媒が流通する冷媒配管である第２の接続配管７は常に低圧で使用される。従って、第１の接続配管６は高圧の設計圧力、第２の接続配管７は低圧の設計圧力で設計することができる。なお、一般にビル用マルチエアコンで使用されている冷媒としてＲ２２があるが、この冷媒は高圧の設計圧力が約３ＭＰａ、低圧側で約１．６ＭＰａであるため、冷媒にＲ２２を使用する空気調和装置の既設配管として、市場で使用されている銅配管の許容圧力は表２に示されるようになっている。この空気調和装置の熱源機と室内機を例えばＲ４１０Ａを冷媒に使用する空気調和装置に更新する場合には、高圧の設計圧力は表２に示すように、約４．２ＭＰａ、低圧の設計圧力は約２．２ＭＰａである。
【００２８】
このため、この発明における空気調和装置において、第１の接続配管６として径が１５．８８のものを、また、第２の接続配管７として径が２８．６のものを使用すれば、両接続配管は、各々、設計圧力が配管の許容値以下となり、使用が可能である。従って、冷媒にＲ２２を使用する冷凍または空気調和装置で使用していた既設配管がＲ４１０Ａを使用する空気調和装置で流用可能となるので、空気調和装置の更新時に生じる既設の冷媒配管の廃材化や新規の冷媒配管を施工するための既設構造物の取り壊し等をなくすることができる他、工事期間も短縮することができる。
【００２９】
また、一般に、動作圧力が高い冷媒では、配管を流れる冷媒の密度が大きくなり、同じ径の冷媒配管を使用しても、動作圧力が低い冷媒よりも動作圧力が高い冷媒の方が、圧力損失が小さくなる傾向がある。図６は、配管長に対する能力の低下比率を動作圧力の異なる冷媒に関して比較した図である。この図から、動作圧力が低い冷媒（Ｒ４０７Ｃ）よりも動作圧力が高い冷媒（Ｒ４１０Ａ）の方が、能力が高くなることが分かる。従って、既設の冷媒配管を流用して動作圧力が高い冷媒を使用する冷凍または空気調和装置に更新することにより、冷凍または空気調和装置の効率を向上させることができる。
【００３０】
更に、このような冷凍または空気調和装置を施工する場合の施工フローを図７に示す。手順は、まず、ステップＳ１で既設ユニット内の旧冷媒を回収する。
次に、ステップＳ２で既設の熱源機と室内機を撤去する。その後、ステップＳ３で既設の冷媒配管を洗浄する。次に、ステップＳ４で新規の熱源機と室内機を据え付ける。続いてステップＳ５で熱源機と室内機を既設もしくは新規の冷媒配管で接続する。次にステップＳ６で冷媒配管内を真空引きし、冷媒チャージを行なう。その後、ステップＳ７で試運転を実施し、更新工事を終了する。
これによって、既設配管内に残留するコンタミを除去した状態で既設配管を流用することができるので、冷凍または空気調和装置におけるコンタミ物質による装置の劣化や膨張弁の詰まりを防止し、機器の信頼性を高めることができる。
【００３１】
また、冷媒としてＲ４１０Ａを使用する場合には、冷凍または空気調和装置の運転を行なう時の動作圧力が高いため、上述のように、圧力損失が小さくなる。
この結果、熱源機と室内機とを接続する冷媒配管での圧力損失が小さくなることで、ロスが削減され、冷凍または空気調和装置の効率を向上させることができる。この効果は、更新前の冷凍または空気調和装置に使用される冷媒の動作圧力が更新後の装置に使用される冷媒の動作圧力よりも低いものであれば、Ｒ４０７Ｃ、Ｒ１３４ａ、Ｒ１２、Ｒ１３等、どのような冷媒を使用した場合にも期待することができる。また、Ｒ２２は塩素を含む冷媒であるが、Ｒ４１０Ａに置き換えることでオゾン破壊係数が０の冷媒となるので、地球環境保護にも役立つものである。
【００３２】
更に、更新後の冷媒をＲ３２とすることによって、地球温暖化係数を小さくすることができるので、この場合にも地球環境保護に役立つものである。
また、流用する既設冷媒配管を装置の更新時に洗浄することにより、既設システムで発生し既設冷媒配管中に残留していた冷凍機油の劣化物等のコンタミを除去した状態で、新しいシステムを構成することができるので、冷凍または空気調和装置の信頼性を高めることができる。
【００３３】
【発明の効果】
この発明に係る冷凍または空気調和装置によれば、既設の冷媒配管を用いて更新前の冷凍または空気調和装置の設計圧力よりも高い設計圧力を持つ冷凍または空気調和装置に更新するようにしているため、熱源機及び室内機の少なくとも一方を更新する場合における更新工事の工期を短縮し、更新コストを低減することができる。また、冷媒配管での圧力損失を低減することで冷凍または空気調和装置の効率を改善することができる。更に、Ｒ２２のように塩素を含む冷媒をＲ４１０Ａのようにオゾン破壊係数が０の冷媒と置き換えれば地球環境保護にも役立つことができ、さらに、更新後の冷媒をＲ３２とすれば、地球温暖化係数を小さくすることができ、地球環境保護に役立つものである。
また、流用する既設冷媒配管を洗浄することにより、既設システムで発生し既設冷媒配管中に残留していた冷凍機油の劣化物等のコンタミを除去した状態で新しいシステムを構成することができるので、冷凍または空気調和装置の信頼性を高めることができる。
【図面の簡単な説明】
【図１】この発明の実施の形態１による冷凍または空気調和装置の構成を示す冷媒回路図である。
【図２】実施の形態１における全冷房運転時の冷媒の流れを示す説明図である。
【図３】実施の形態１における全暖房運転時の冷媒の流れを示す説明図である。
【図４】実施の形態１における暖房主体運転時の冷媒の流れを示す説明図である。
【図５】実施の形態１における冷房主体運転時の冷媒の流れを示す説明図である。
【図６】配管長に対する冷媒の性能比率を示す説明図である。
【図７】この発明における装置更新時の手順を示すフロー図である。
【符号の説明】
１ 圧縮機、 ２ 四方切換弁、 ３ 熱源側熱交換器、４ アキュムレータ、 ５ａ 第１の逆止弁、 ５ｂ 第２の逆止弁、５ｃ 第３の逆止弁、 ５ｄ 第４の逆止弁、 ６ 第１の接続配管、６ｂ、６ｃ 負荷側の第１の接続配管、 ７ 第２の接続配管、７ｂ、７ｃ 負荷側の第２の接続配管、１１ｂ、１１ｃ 負荷側熱交換器、 １２ｂ、１２ｃ 流量制御装置、１３ 弁装置、 １３ａ 第１の弁装置、 １３ｂ 第２の弁装置、１４ 気液分離器、 １５ 第１の熱交換部、１６ 第２の流量制御装置、 １７ 第２の熱交換部、１８ バイパス配管、 １９ 第３の流量制御装置、 Ａ 熱源機、Ｂ、Ｃ 室内機、 Ｄ 分流コントローラ。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention diverts an existing refrigerant pipe for an old refrigerant to a refrigerant pipe connecting a refrigeration or air conditioning apparatus, particularly, a heat source unit and an indoor unit, and updates the heat source unit and the indoor unit to equipment for a new refrigerant. It relates to a refrigeration or air conditioner.
[0002]
[Prior art]
This type of conventional refrigeration or air conditioner generally includes a refrigerant circuit having the following devices and functions. That is, a compressor, a four-way switching valve that switches the direction in which the high-temperature and high-pressure gas refrigerant discharged from the compressor flows between a cooling operation and a heating operation, and acts as a condenser during cooling, and as an evaporator during heating. A heat source side heat exchanger that acts, and a heat source unit composed of an accumulator that separates the gas refrigerant returned from the evaporator into gas-liquid and returns it to the compressor, and acts as an evaporator during cooling and as a condenser during heating An indoor unit including a load-side heat exchanger that operates and a flow control device such as a throttle device connected to the load-side heat exchanger, and first and second connection pipes that connect the heat source unit and the indoor unit. Constitute a refrigerant circuit.
[0003]
In the refrigeration or air-conditioning apparatus having such a refrigerant circuit, the flow of the refrigerant when performing the cooling operation will be described. The high-temperature, high-pressure gas refrigerant discharged from the compressor flows into the heat source side heat exchanger via the four-way switching valve, where it is condensed and liquefied.
The liquefied refrigerant flows through the first connection pipe, which is a liquid pipe, into the expansion device of the indoor unit, where it is throttled to a low pressure, flows into the load side heat exchanger, and evaporates and evaporates.
The low-pressure gas refrigerant that has exited the load-side heat exchanger reaches the four-way switching valve of the heat source unit via the second connection pipe, which is a gas pipe, and then returns to the compressor via the accumulator.
[0004]
Next, the flow of the refrigerant when performing the heating operation will be described. The flow path of the high-temperature, high-pressure gas refrigerant discharged from the compressor is switched by a four-way switching valve, flows into the load-side heat exchanger of the indoor unit via the second connection pipe that is a gas pipe, and condenses there. Liquefy. The liquefied refrigerant is throttled to a low pressure by the expansion device to become a low-pressure two-phase refrigerant, and flows into the heat source side heat exchanger of the heat source device via the first connection pipe which is a liquid pipe. Here, after the two-phase refrigerant evaporates and evaporates, the low-pressure gas refrigerant returns to the compressor via the four-way switching valve and the accumulator. (See, for example, Patent Document 1).
[0005]
[Patent Document 1]
Japanese Patent No. 3361765 (paragraphs 0063-0073, FIG. 1)
[0006]
[Problems to be solved by the invention]
Since the conventional refrigeration or air-conditioning apparatus is configured as described above, the four-way switching valve switches between the cooling operation and the heating operation, and the flow of the refrigerant flowing to the indoor unit is reversed. As a result, in the first and second connection pipes connecting the heat source unit and the indoor unit, the first connection pipe, which is a liquid pipe, has a high pressure and the second connection pipe, which is a gas pipe, has a low pressure during cooling. On the other hand, during heating, the first connection pipe, which is a liquid pipe, has a low pressure, and the second connection pipe, which is a gas pipe, has a high pressure. Here, the allowable pressure of a refrigerant pipe for an air conditioner generally used in the market differs depending on the pipe diameter, and as shown in Table 1, as the pipe diameter increases, the allowable pressure decreases.
[Table 1]

[0007]
On the other hand, in a multi-air conditioner for buildings using R22 or R407C as a refrigerant, as shown in Table 2, the design pressure of the high pressure is close to the allowable pressure of the gas pipes. Of the heat source units and the indoor units are limited to those using a refrigerant close to the operating pressure of the heat source unit and the indoor units before the update.
[Table 2]

In the case of updating to a system that uses a refrigerant (for example, R410A) having an operating pressure higher than the operating pressure of the existing refrigeration or air conditioner, the existing refrigerant pipe cannot be used, so that the construction period becomes longer and the cost increases. There was a point.
Furthermore, as the demand for energy savings has been increasing year by year, it has not been possible to satisfy these demands simply by improving the performance of the elements used in the equipment, and the cost tolerance of the equipment has been reduced. there were.
[0008]
The present invention has been made to solve the above-described problems, and the existing refrigerant piping is diverted to shorten the period of renewal work, reduce renewal costs, and reduce pressure loss in the refrigerant piping. Accordingly, it is an object of the present invention to provide a refrigeration or air-conditioning apparatus that improves the efficiency of the apparatus and also contributes to protection of the global environment, and a method of updating the same.
[0009]
[Means for Solving the Problems]
A refrigeration or air-conditioning apparatus according to the present invention is a heat source having a compressor, a four-way switching valve for switching a flow path of a refrigerant discharged from the compressor, and a heat source side heat exchanger connected to the four-way switching valve. Unit, an indoor unit having a load-side heat exchanger and a flow control device connected thereto, and connecting the heat source unit and the indoor unit via first and second connection pipes, In a refrigeration or air conditioner equipped with a flow dividing controller having a valve device for switchably connecting one end of a heat exchanger to the first and second connection pipes, the first and second connection pipes are connected to each other. An existing connection pipe for the old refrigerant is provided, and at least one of the heat source unit and the indoor unit is an updater for a new refrigerant having a higher operating pressure than the old refrigerant.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a refrigerant circuit diagram illustrating a configuration of a refrigeration or air-conditioning apparatus according to Embodiment 1, illustrating an example of a multi-room heat pump air-conditioning apparatus that connects a plurality of indoor units to one heat source unit. In addition, an example is shown in which cooling and heating can be selectively performed for each indoor unit, and an indoor unit that performs cooling and an indoor unit that performs heating can be simultaneously operated. Although FIG. 1 illustrates the case where two indoor units and one shunt controller are connected to one heat source unit, the same operation is performed when three or more indoor units and two or more shunt controllers are connected. Needless to say, we can do it.
[0011]
In FIG. 1, A is a heat source unit, and B and C are indoor units connected in parallel to each other as described later, and have the same configuration. D is a shunt controller that connects the heat source unit A and the indoor units B and C, and the configuration will be described later.
The heat source device A is constituted by the components described below. That is, a compressor 1, a four-way switching valve 2 connected to the compressor 1 for switching the flow direction of the refrigerant, a heat source side heat exchanger 3, and an accumulator connected between the four-way switching valve 2 and the compressor 1. 4 and a first reverse which is provided between the heat source side heat exchanger 3 and a first connection pipe 6 described later, and allows the refrigerant to flow only in the direction from the heat source side heat exchanger 3 to the first connection pipe 6. A second check valve that is provided between the stop valve 5a, the four-way switching valve 2 and a second connection pipe 7 described later, and allows the refrigerant to flow only in the direction from the second connection pipe 7 to the four-way switching valve 2. 5b, a third check valve 5c provided between the four-way switching valve 2 and the first connection pipe 6 and allowing the refrigerant to flow only in the direction from the four-way switching valve 2 to the first connection pipe 6; The heat source side heat exchanger 3 is provided between the second heat exchanger 3 and the second connection pipe 7. It is composed of a fourth check valve 5d that allows only refrigerant flow in the direction.
[0012]
Further, the indoor units B and C are respectively constituted by load-side heat exchangers 11b and 11c, and flow control devices 12b and 12c such as expansion devices connected in series to the load-side heat exchangers 11b and 11c. . Each of the flow control devices 12b and 12c is controlled to open and close by the degree of superheat on the outlet side of the load side heat exchangers 11b and 11c during cooling, and by the degree of supercooling on the outlet side during heating. ing. Further, the branch controller D is connected to the thick second connection pipe 7 connected to the four-way switching valve 2 and the heat source side heat exchanger 3, and the heat source unit A is connected to the first connection pipe 6 which is thinner than the second connection pipe 7. Connected to the load-side second heat exchangers 11b and 11c of the indoor units B and C, and to the flow control devices 12b and 12c of the indoor units B and C on the load side. The first connection pipes 6b and 6c on the load side are connected to the indoor units B and C, respectively, and have the following internal configuration.
[0013]
That is, reference numeral 13 denotes a valve device for switchably connecting the second connection pipes 7b and 7c on the load side to the first connection pipe 6 or the second connection pipe 7, one end of which is the second connection pipe on the load side. 7b, 7c, two other valve devices 13a, the other ends of which are connected together and connected to the first connection pipe 6, and one end of which is connected to the second connection pipes 7b, 7c on the load side. And two second valve devices 13b connected together and the other end collectively connected to the second connection pipe 7. The first valve device 13a is opened, and the second valve device 13b is opened. , The second connection pipes 7b and 7c on the load side are connected to the first connection pipe 6, and the first valve device 13a is closed and the second valve device 13b is opened. Connecting the second connection pipes 7b and 7c on the load side to the second connection pipe 7. .
[0014]
Further, a gas-liquid separator 14 is provided in the middle of the first connection pipe 6, and a gas phase portion thereof is connected to the first valve device 13 a via the latter half of the first connection pipe 6, The unit is connected to the first connection pipes 6b and 6c on the load side via the first heat exchange unit 15, the second open / close flow control device 16 and the second heat exchange unit 17. In addition, a part of the liquid refrigerant from the gas-liquid separator 14 exchanges heat with the second heat exchange unit 17 and the first heat exchange unit 15 via the third flow control device 19 provided in the bypass pipe 18. The liquid refrigerant from the gas-liquid separator 14 is supercooled and returned to the second connection pipe 7.
[0015]
With the refrigeration or air-conditioning apparatus of the first embodiment configured as described above, the three types of operation are roughly divided as described above. That is, when the cooling operation is performed by all of the plurality of indoor units, when the heating operation is performed by all of the plurality of indoor units, a part of the plurality of indoor units performs the cooling operation, and the other Is the case where the heating operation is performed (simultaneous cooling and heating operation). Further, for simultaneous cooling and heating operation, two modes of operation are performed. That is, a case where most of the indoor units among the plurality of indoor units perform the heating operation (heating-main operation), and a case where most of the indoor units among the plurality of indoor units perform the cooling operation (cooling-main operation). is there.
[0016]
First, a cooling only operation for cooling all the indoor units will be described with reference to FIG. That is, as shown by a solid line arrow in FIG. 2, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, exchanges heat with the heat source side heat exchanger 3, and is condensed. Thereafter, the gas flows into the diversion controller D through the first check valve 5a and the first connection pipe 6. The refrigerant flowing into the branch flow controller D passes through the gas-liquid separator 14 and the second flow control device 16 in this order, passes through the first connection pipes 6b and 6c on the load side, flows into the indoor units B and C, and The pressure is reduced to a low pressure by the flow controllers 12b and 12c controlled by the degree of superheat at the outlets of the load-side heat exchangers 11b and 11c, and the load-side heat exchangers 11b and 11c exchange heat with room air to evaporate and gasify. Cool the room.
The gaseous refrigerant passes through the second connection pipes 7b and 7c on the load side and the second valve device 13b, passes through the second connection pipe 7, the second check valve 5b, and the four-way switching valve 2 A circulation cycle is drawn into the compressor 1 via the accumulator 4 to perform a cooling operation. At this time, the first valve device 13a is closed and the second valve device 13b is open.
[0017]
Further, since the second connection pipe 7 has a low pressure and the first connection pipe 6 has a high pressure, the refrigerant necessarily flows to the first check valve 5a and the second check valve 5b.
Further, during this cycle, a part of the refrigerant that has passed through the second flow control device 16 enters the bypass pipe 18 via the second heat exchange unit 17 and the third flow control device 19, and the third flow control The pressure is reduced to a low pressure in the device 19, heat is exchanged with the refrigerant flowing into the first connection pipes 6 b and 6 c on the load side in the second heat exchange section 17, and the first heat exchange section 15 Then, the evaporated refrigerant that exchanges heat with the refrigerant flowing into the second flow control device 16 enters the second connection pipe 7 and passes through the second check valve 5 b, the four-way switching valve 2, and the accumulator 4. After that, it is sucked into the compressor 1. On the other hand, the refrigerant that has undergone heat exchange in the first heat exchange unit 15 and has an increased degree of subcooling flows into the indoor units B and C that are about to be cooled via the first connection pipes 6b and 6c on the load side. I do.
[0018]
Next, a heating only operation for heating all the indoor units will be described with reference to FIG. In this case, the four-way switching valve 2 is switched, and the flow of the refrigerant becomes as shown by the solid 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 third check valve 5c, and the first connection pipe 6, and flows into the branch controller D. The refrigerant flowing into the branch controller D passes through the gas-liquid separator 14, the second half of the first connection pipe 6, the first valve device 13a, the second connection pipes 7b and 7c on the load side, and , C and exchanges heat with room air to condense and liquefy, thereby heating the room.
[0019]
Then, the refrigerant in the liquid state passes through the flow control devices 12b, 12c controlled by the degree of supercooling at the outlets of the load-side heat exchangers 11b, 11c, from the first connection pipes 6b, 6c on the load side. The gas flows into the third flow control device 19 in the bypass pipe 18 and is reduced to a low-pressure gas-liquid two-phase state. The refrigerant decompressed to a low pressure passes through the second heat exchange section 17 and the first heat exchange section 15, passes through the second connection pipe 7, passes through the fourth check valve 5 d, and the heat source side heat exchanger 3 The refrigerant which has flowed into the refrigerant, exchanged heat and evaporated to be in a gaseous state forms a circulation cycle which 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 valve device 13a is open, and the second valve device 13b is closed. In addition, since the second connection pipe 7 has a low pressure and the first connection pipe 6 has a high pressure, the refrigerant necessarily flows to the third check valve 5c and the fourth check valve 5d.
[0020]
Next, the case of mainly heating in the simultaneous cooling and heating operation will be described with reference to FIG. Here, a case where the indoor unit B is about to heat and the indoor unit D is about to cool will be described. That is, as shown by the solid arrows in FIG. 4, the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 passes through the four-way switching valve 2, the third check valve 5 c, and the first connection pipe 6. , Flows into the shunt controller D. The refrigerant flowing into the diversion controller D passes through the gas-liquid separator 14, the second half of the first connection pipe 6, the first valve device 13 a, and the second connection pipe 7 b on the load side in that order, and the room to be heated is heated. The heat flows into the heat exchanger B and exchanges heat with the room air in the load side heat exchanger 11b to condense and liquefy, thereby heating the room.
The refrigerant in the liquid state is controlled by the degree of supercooling at the outlet of the load side heat exchanger 11b, and is slightly reduced in pressure through the flow control device 12b in a substantially fully opened state, so that the intermediate pressure between the high pressure and the low pressure (intermediate pressure) ), A part of the refrigerant flowing into the first connection pipe 6b on the load side passes through the second heat exchange unit 17 as shown by the arrow R, and the refrigerant on the load side connected to the indoor unit C to be cooled. After passing through the first connection pipe 6c, the pressure is reduced by the flow controller 12c controlled by the degree of superheat at the outlet of the load-side heat exchanger 11c, and then enters the load-side heat exchanger 11c of the indoor unit C to exchange heat and evaporate. It becomes a gas state, cools the room, and flows into the second connection pipe 7 via the second valve device 13b connected to the indoor unit C.
[0021]
On the other hand, another part of the refrigerant for heating the indoor unit B flowing from the indoor unit B to the second heat exchange unit 17 of the branching controller D passes through the bypass pipe 18 to the high pressure and flow rate of the first connection pipe 6. Since it reaches the second connection pipe 7 as described above through the openable and closable third flow control device 19 which is controlled so as to keep the difference from the intermediate pressure at the outlet of the control device 12b constant, the room here is used. The refrigerant which has cooled the unit C and flows into the second connection pipe 7 having a large thickness, flows into the fourth check valve 5d and the heat source side heat exchanger 3 and exchanges heat to evaporate into a gaseous state. Constitutes a circulation cycle that is sucked into the compressor 1 through the four-way switching valve 2 and the accumulator 4, and performs the heating main operation.
[0022]
At this time, the first valve device 13a connected to the indoor unit B to be heated is open, the second valve device 13b is closed, and the first valve connected to the indoor unit C to be cooled. The device 13a is closed and the second valve device 13b is open.
In addition, since the second connection pipe 7 has a low pressure and the first connection pipe 6 has a high pressure, the refrigerant necessarily flows to the third check valve 5c and the fourth check valve 5d.
[0023]
In this cycle, the refrigerant that has entered the bypass pipe 18 is reduced in pressure to a low pressure by the third flow control device 19 and flows into the first connection pipe 6c on the load side in the second heat exchange unit 17. Heat exchange is performed with the refrigerant, and further, heat exchange is performed with the refrigerant flowing into the second flow control device 16 in the first heat exchange unit 15, and the evaporated refrigerant flows to the second connection pipe 7. Then, the gas flows into the heat source side heat exchanger 3 via the fourth check valve 5d, exchanges heat, and evaporates 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 second heat exchange unit 17 and has an increased degree of subcooling flows into the indoor unit C that is about to be cooled as described above.
[0024]
Next, a case where cooling is mainly performed in simultaneous cooling and heating operation will be described with reference to FIG. Here, a case where the indoor unit B is about to heat and the indoor unit C is about to cool will be described. That is, as shown by the solid line arrows in FIG. 5, 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 side heat exchanger 3 to be cooled. The refrigerant becomes a liquid two-phase high-temperature and high-pressure refrigerant and flows into the branch controller D through the first check valve 5a and the first connection pipe 6. The refrigerant flowing into the diversion controller D is sent to the gas-liquid separator 14, where it is separated into a gas refrigerant and a liquid refrigerant. The separated gas refrigerant passes through the second half of the first connection pipe 6 and is going to be heated in the order of the first valve device 13a of the valve device 13 of the branch controller D and the second connection pipe 7b on the load side. The refrigerant flows into the indoor unit B, exchanges heat with the indoor air in the load side heat exchanger 11b, condenses and liquefies, and heats the room.
[0025]
Further, the pressure is controlled by the degree of supercooling at the outlet of the load-side heat exchanger 11b, and is slightly reduced through the flow control device 12b in a substantially fully opened state, and becomes an intermediate pressure between the high pressure and the low pressure (intermediate pressure). Flows into the bypass pipe 18 through the connection pipe 6b, and is reduced to a low pressure by the third flow control device 19, and the refrigerant flows into the first connection pipe 6c on the load side in the second heat exchange section 17 with the refrigerant. Heat exchange is performed between the refrigerant and the refrigerant that has exchanged heat with the refrigerant flowing into the second flow control device 16 in the first heat exchange unit 15, and the evaporated refrigerant reaches the second connection pipe 7. On the other hand, the remaining liquid refrigerant separated by the gas-liquid separator 14 of the branch controller D is heat-exchanged in the first heat exchange unit 15 to increase the degree of supercooling. As shown by an arrow through the second flow control device 16 which is controlled so as to flow into the indoor unit C through the first connection pipe 6c on the load side. The refrigerant is reduced in pressure to a low pressure by the flow controller 12c controlled by the degree of superheat at the outlet of the load side heat exchanger 11c of the indoor unit C, and exchanges heat with indoor air in the load side heat exchanger 11c to evaporate. It is gasified and cools the room.
Then, the gaseous refrigerant flows into the second connection pipe 7 via the second connection pipe 7c on the load side and the second valve device 13b, and flows into the second connection pipe 7 via the bypass pipe 18. After merging with the above-mentioned heating refrigerant of the indoor unit B that flows in, a circulation cycle is drawn into the compressor 1 through the second check valve 5b, the four-way switching valve 2, and the accumulator 4, and the cooling main operation is performed. Do.
[0026]
At this time, the first valve device 13a connected to the indoor unit C to be cooled is closed, the second valve device 13b is opened, and the first valve connected to the indoor unit B to be heated. The device 13a is open and the second valve device 13b is closed. Further, since the second connection pipe 7 has a low pressure and the first connection pipe 6 has a high pressure, the refrigerant necessarily flows to the first check valve 5a and the second check valve 5b.
[0027]
Since the refrigeration or air-conditioning apparatus according to this embodiment is configured as described above, the first connection pipe 6, which is the refrigerant pipe through which the liquid refrigerant flows, is always used at a high pressure, and the refrigerant through which the gas refrigerant flows. The second connection pipe 7, which is a pipe, is always used at a low pressure. Therefore, the first connection pipe 6 can be designed at a high design pressure and the second connection pipe 7 can be designed at a low design pressure. Note that R22 is generally used as a refrigerant in a building multi-air conditioner. Since this refrigerant has a high-pressure design pressure of about 3 MPa and a low-pressure side of about 1.6 MPa, an air conditioner using R22 as the refrigerant is used. Table 2 shows the allowable pressures of copper pipes used in the market as existing pipes. When the heat source unit and the indoor unit of this air conditioner are updated to an air conditioner using, for example, R410A as a refrigerant, as shown in Table 2, the design pressure of high pressure is about 4.2 MPa, and the design pressure of low pressure is It is about 2.2 MPa.
[0028]
For this reason, in the air conditioner of the present invention, if the first connection pipe 6 having a diameter of 15.88 and the second connection pipe 7 having a diameter of 28.6 are used, the two connection pipes can be connected. Each of the pipes can be used because the design pressure is below the allowable value of the pipe. Therefore, the existing piping used in the refrigeration or air conditioner using R22 as the refrigerant can be diverted in the air conditioner using R410A. In addition to eliminating the destruction of the existing structure for installing a new refrigerant pipe, the construction period can be shortened.
[0029]
Also, in general, in a refrigerant having a high operating pressure, the density of the refrigerant flowing through the pipe increases, and even when a refrigerant pipe having the same diameter is used, a refrigerant having a high operating pressure has a higher pressure loss than a refrigerant having a low operating pressure. Tend to be smaller. FIG. 6 is a diagram comparing the rate of decrease in capacity with respect to pipe length for refrigerants having different operating pressures. From this figure, it can be seen that the capacity of the refrigerant (R410A) having a higher operating pressure is higher than that of the refrigerant (R407C) having a lower operating pressure. Therefore, the efficiency of the refrigeration or air-conditioning apparatus can be improved by diverting the existing refrigerant pipe to a refrigeration or air-conditioning apparatus using a refrigerant having a high operating pressure.
[0030]
FIG. 7 shows a construction flow when such a refrigeration or air-conditioning apparatus is constructed. The procedure first recovers the old refrigerant in the existing unit in step S1.
Next, in step S2, the existing heat source unit and indoor unit are removed. Then, the existing refrigerant pipe is washed in step S3. Next, in step S4, a new heat source unit and an indoor unit are installed. Subsequently, in step S5, the heat source unit and the indoor unit are connected by an existing or new refrigerant pipe. Next, in step S6, the inside of the refrigerant pipe is evacuated to charge the refrigerant. Thereafter, a trial operation is performed in step S7, and the renewal work ends.
As a result, the existing pipes can be reused in a state where the contaminants remaining in the existing pipes are removed, thereby preventing equipment deterioration and clogging of expansion valves due to contaminants in the refrigeration or air-conditioning apparatus, and reliability of the equipment. Can be increased.
[0031]
Further, when R410A is used as the refrigerant, the operating pressure during operation of the refrigeration or air conditioner is high, so that the pressure loss is reduced as described above.
As a result, the pressure loss in the refrigerant pipe connecting the heat source unit and the indoor unit is reduced, so that the loss is reduced and the efficiency of the refrigeration or air conditioner can be improved. This effect can be obtained if the operating pressure of the refrigerant used in the refrigeration or air-conditioning apparatus before the update is lower than the operating pressure of the refrigerant used in the apparatus after the update, such as R407C, R134a, R12, R13, and the like. This can be expected when any refrigerant is used. Further, R22 is a refrigerant containing chlorine, but since it becomes a refrigerant having an ozone depletion coefficient of 0 by replacing it with R410A, it is also useful for protecting the global environment.
[0032]
Furthermore, by setting the refrigerant after the update to R32, the global warming potential can be reduced, which is also useful for protecting the global environment.
In addition, a new system is configured by cleaning existing refrigerant pipes to be diverted at the time of updating the apparatus, thereby removing contaminants such as deterioration of refrigerating machine oil generated in the existing system and remaining in the existing refrigerant pipes. Therefore, the reliability of the refrigeration or air conditioner can be improved.
[0033]
【The invention's effect】
According to the refrigeration or air-conditioning apparatus according to the present invention, the refrigeration or air-conditioning apparatus having a design pressure higher than the design pressure of the refrigeration or air-conditioning apparatus before the update is updated using the existing refrigerant pipe. Therefore, it is possible to shorten the period of the renewal work when renewing at least one of the heat source unit and the indoor unit, and to reduce the renewal cost. Further, the efficiency of the refrigeration or air conditioner can be improved by reducing the pressure loss in the refrigerant pipe. Further, replacing a refrigerant containing chlorine such as R22 with a refrigerant having an ozone depletion potential of 0, such as R410A, can also help protect the global environment. Further, if the updated refrigerant is R32, global warming can be achieved. The coefficient can be reduced, which is useful for protecting the global environment.
In addition, by cleaning the existing refrigerant pipe to be diverted, a new system can be configured in a state in which contamination such as deterioration of refrigerating machine oil generated in the existing system and remaining in the existing refrigerant pipe has been removed, The reliability of the refrigeration or air conditioner can be improved.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram showing a configuration of a refrigeration or air-conditioning apparatus according to Embodiment 1 of the present invention.
FIG. 2 is an explanatory diagram showing a flow of a refrigerant during a cooling only operation in the first embodiment.
FIG. 3 is an explanatory diagram illustrating a flow of a refrigerant during a heating only operation in the first embodiment.
FIG. 4 is an explanatory diagram illustrating a flow of a refrigerant during a heating-main operation according to the first embodiment.
FIG. 5 is an explanatory diagram showing a flow of a refrigerant during a cooling main operation in the first embodiment.
FIG. 6 is an explanatory diagram showing a performance ratio of a refrigerant to a pipe length.
FIG. 7 is a flowchart showing a procedure at the time of updating a device according to the present invention.
[Explanation of symbols]
Reference Signs List 1 compressor, 2 four-way switching valve, 3 heat source side heat exchanger, 4 accumulator, 5a first check valve, 5b second check valve, 5c third check valve, 5d fourth check valve 6 First connection pipe, 6b, 6c First connection pipe on the load side, 7 Second connection pipe, 7b, 7c Second connection pipe on the load side, 11b, 11c Load side heat exchanger, 12b, 12c flow control device, 13 valve device, 13a first valve device, 13b second valve device, 14 gas-liquid separator, 15 first heat exchange section, 16 second flow control device, 17 second heat Exchange unit, 18 bypass piping, 19 third flow control device, A heat source unit, B, C indoor unit, D diversion controller.

Claims (4)

A heat source machine having a compressor, a four-way switching valve for switching the flow path of the refrigerant discharged from the compressor, and a heat source side heat exchanger connected to the four-way switching valve, a load side heat exchanger, An indoor unit having a flow control device connected thereto, and connecting the heat source unit and the indoor unit via first and second connection pipes, and connecting one end of the load-side heat exchanger to the In a refrigeration or air-conditioning apparatus provided with a branch controller having a valve device switchably connected to the first and second connection pipes, the first and second connection pipes may be existing connection pipes for old refrigerant, A refrigeration or air-conditioning apparatus, wherein at least one of the heat source unit and the indoor unit is a renewal unit for a new refrigerant having a higher operating pressure than the old refrigerant. The valve device has two valves connected in parallel to one end of the load-side heat exchanger, one valve is connected to the first connection pipe, and the other valve is connected to the second connection pipe. The refrigeration or air-conditioning apparatus according to claim 1, wherein the refrigeration or air-conditioning apparatus is connected to a connection pipe. 3. The refrigeration or air-conditioning apparatus according to claim 1, wherein the first connection pipe forms a flow path of a high-pressure refrigerant, and the second connection pipe forms a flow path of a low-pressure refrigerant. The refrigeration or air-conditioning apparatus according to any one of claims 1 to 3, wherein the first and second connection pipes are washed when at least one of the heat source unit and the indoor unit is updated. Refrigeration or air conditioner renewal method.

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