JP2004205109A

JP2004205109A - Pipe washing method for air conditioning equipment, its device and system and control device for pipe washing system

Info

Publication number: JP2004205109A
Application number: JP2002374641A
Authority: JP
Inventors: Takaaki Tamura; 隆明田村
Original assignee: Sanyo Electric Co Ltd; Sanyo Electric Air Conditioning Co Ltd
Current assignee: Sanyo Electric Co Ltd; Sanyo Electric Air Conditioning Co Ltd
Priority date: 2002-12-25
Filing date: 2002-12-25
Publication date: 2004-07-22

Abstract

PROBLEM TO BE SOLVED: To improve the washing efficiency of pipes between units. SOLUTION: The pipe washing system for air conditioning equipment 10 consisting of an outdoor unit 11 having a compressor 20 and an outdoor heat exchanger 24 arranged in an outdoor refrigerant pipe 19, indoor units 12A, 12B each having an indoor heat exchanger 18 arranged in an indoor refrigerant pipe 16, and unit-to-unit pipes 15 connecting the outdoor refrigerant pipe 19 to each of the indoor refrigerant pipes 16 and each having a gas pipe 13 and a liquid pipe 14, comprises an oil separator 32 and a solenoid valve 34 installed between the outdoor refrigerant pipe 19 and the gas pipe 13. With the solenoid valve 34 opened/closed during heating operation, refrigerant from which mineral oil is removed by the oil separator 32 is intermittently discharged to the gas pipe 13 to wash pipes 15 between the units. COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、建物等に設置されたユニット間配管を洗浄して利用可能とする空気調和装置の配管洗浄方法、配管洗浄装置、空気調和装置の配管洗浄システム、及び配管洗浄システムの制御装置に関する。
【０００２】
【従来の技術】
圧縮機及び室外熱交換器が室外冷媒配管に配設された室外機と、室内熱交換器が室内冷媒配管に配設された室内機と、室外冷媒配管と室内冷媒配管を接続し、ガス管及び液管を備えてなるユニット間配管とを有して構成される空気調和装置が知られている。
【０００３】
このような空気調和装置のうち、ビルディングなどの建物に設置されるものでは、室外機と室内機をつなぐユニット間配管が建物に埋め込まれ、更に配管長が長いことが一般的である。また、室内機が複数台存在する場合、これらの室内機に接続される上記ユニット間配管は、枝管が多く複雑な形状となっている。
【０００４】
空気調和装置の室外機及び室内機を交換する際に、建物内に設置された上記ユニット間配管をも交換することは、このユニット間配管の寿命に余裕がある場合に無駄であり、有効に利用されるべきである。
【０００５】
但し、既設の空気調和装置と新設の空気調和装置との間で使用される冷媒が異なる場合には、これらの冷媒に対応して冷凍機油も異なる。このため、既設の空気調和装置のユニット間配管を残し、室外機及び室内機を交換する際には、この据え置かれたユニット間配管内に残留する冷凍機油を除去する必要がある。
【０００６】
従来、既設の空気調和装置について、室外機と室内機を新規に交換し、室外機と室内機とを接続するユニット間配管を交換しないで、室外機側の室外冷媒配管に、ユニット間配管に流通する冷媒から冷凍機油等の異物を捕捉する手段を設けたものが知られている（例えば、特許文献１参照。）。
【０００７】
【特許文献１】
特開２０００−９３６８号公報
【０００８】
【発明が解決しようとする課題】
上述のユニット間配管を洗浄する空気調和装置では、ユニット間配管の液管内は、液冷媒が流れるため液管内の冷凍機油が流れやすく良好に洗浄できるものである。しかし、ユニット間配管のガス管内は、ガス冷媒が流れるため、冷凍機油が流れにくく残留しやすい。そして、ガス管内の冷凍機油を良好に除去するためには、洗浄のための運転が長時間となってしまい、効率的ではない。
【０００９】
本発明の目的は、上述の事情を考慮してなされたものであり、ユニット間配管の洗浄効率の向上を図る空気調和装置の配管洗浄方法、配管洗浄装置、空気調和装置の配管洗浄システム、及び配管洗浄システムの制御装置を提供することにある。
【００１０】
【課題を解決するための手段】
上記課題を解決するため、圧縮機及び室外熱交換器が室外冷媒配管に配設された室外機と、室内熱交換器が室内冷媒配管に配設された室内機と、前記室外冷媒配管と前記室内冷媒配管を接続し、ガス管及び液管を備えてなるユニット間配管と、を有する空気調和装置の配管洗浄方法において、前記圧縮機を運転し、前記室外冷媒配管と前記ガス管との間で、前記圧縮機から吐出されたガス冷媒に含まれる冷凍機油を除去する油除去工程と、前記冷凍機油が除去された冷媒を間欠的に前記ガス管に吐出させて、前記ユニット間配管を冷媒で洗浄する洗浄工程とを備えたことを特徴とするものである。
【００１１】
また、圧縮機及び室外熱交換器が室外冷媒配管に配設された室外機と、室内熱交換器が室内冷媒配管に配設された室内機と、前記室外冷媒配管と前記室内冷媒配管を接続し、ガス管及び液管を備えてなるユニット間配管と、を有する空気調和装置の配管洗浄方法において、暖房運転し、前記室外冷媒配管と前記ガス管との間で、前記圧縮機から吐出されたガス冷媒に含まれる冷凍機油を除去する油除去工程と、前記冷凍機油が除去された冷媒を間欠的に前記ガス管に吐出させて、前記ユニット間配管を冷媒で洗浄する洗浄工程とを備えたことを特徴とするものである。
【００１２】
また、圧縮機及び室外熱交換器が室外冷媒配管に配設された室外機と、室内熱交換器が室内冷媒配管に配設された室内機と、前記室外冷媒配管と前記室内冷媒配管を接続し、ガス管及び液管を備えてなるユニット間配管と、を有する空気調和装置に設置される配管洗浄装置おいて、前記室外冷媒配管と前記ガス管との間に設置され、オイルセパレータ及びバルブを有し、前記圧縮機から吐出され前記オイルセパレータで冷凍機油が除去された冷媒を、前記バルブの開閉により間欠的に前記ガス管に吐出させ、前記ユニット間配管を冷媒で洗浄することを特徴とするものである。
【００１３】
また、圧縮機及び室外熱交換器が室外冷媒配管に配設された室外機と、室内熱交換器が室内冷媒配管に配設された室内機と、前記室外冷媒配管と前記室内冷媒配管を接続し、ガス管及び液管を備えてなるユニット間配管と、を有する空気調和装置の配管洗浄システムにおいて、前記室外冷媒配管と前記ガス管との間で、前記圧縮機から吐出されたガス冷媒に含まれる冷凍機油を除去する油除去手段と、前記冷凍機油が除去された冷媒の前記ガス管への供給／遮断を切り替える切替手段とを備え、前記冷媒を間欠的に前記ガス管に吐出させることにより、前記ユニット間配管を洗浄することを特徴とするものである。
【００１４】
この場合において、前記切替手段を制御する制御手段を備えてもよい。
【００１５】
また、圧縮機及び室外熱交換器が室外冷媒配管に配設された室外機と、室内熱交換器が室内冷媒配管に配設された室内機と、前記室外冷媒配管と前記室内冷媒配管を接続し、ガス管及び液管を備えてなるユニット間配管と、を有する空気調和装置の配管洗浄システムにおいて、前記室外冷媒配管と前記ガス管との間にオイルセパレータ及びバルブを設置し、暖房運転を行い、前記バルブの開閉により、前記オイルセパレータで冷凍機油が除去された冷媒を、間欠的に前記ガス管に吐出させ、前記ユニット間配管を冷媒で洗浄することを特徴とするものである。
【００１６】
また、圧縮機及び室外熱交換器が室外冷媒配管に配設された室外機と、室内熱交換器が室内冷媒配管に配設された室内機と、前記室外冷媒配管と前記室内冷媒配管を接続し、ガス管及び液管を備えてなるユニット間配管と、を有する空気調和装置の配管洗浄システムの制御装置において、前記室外冷媒配管と前記ガス管との間に、前記圧縮機から吐出されたガス冷媒に含まれる冷凍機油を除去するオイルセパレータ及びバルブが設置され、暖房運転を行い、前記バルブを開閉する制御を行うことで、前記オイルセパレータで冷凍機油が除去された冷媒を、間欠的に前記ガス管に吐出させ、前記ユニット間配管を冷媒で洗浄するようにしたことを特徴とするものである。
【００１７】
【発明の実施の形態】
以下、本発明の実施の形態を、図面に基づき説明する。
【００１８】
図１は、本発明に係る空気調和装置の配管洗浄システムにおける一実施の形態を示す系統図である。
【００１９】
図２は、配管洗浄装置３１を取り付ける前の既設の空気調和装置１０を示している。この空気調和装置１０は、ガス管１３及び液管１４を備えてなるユニット間配管１５に室外機１１が接続されるとともに、複数台（図２では、２台）の室内機１２Ａ、１２Ｂが並列に接続されて構成される。
【００２０】
室内機１２Ａ、１２Ｂは、室内冷媒配管１６に室内電子膨張弁１７及び室内熱交換器１８が配設されて構成され、室内冷媒配管１６の一端がガス管１３に、他端が室内電子膨張弁１７を介して液管１４にそれぞれ接続される。室内熱交換器１８には、この室内熱交換器１８へ送風する室内ファン２２が隣接して配置されている。また、室内機１２Ａ、１２Ｂには、室内電子膨張弁１７及び室内ファン２２を制御する室内制御装置４２が設けられている。室内電子膨張弁１７は、室内制御装置４２により弁開度が空調負荷に応じて調整される。
【００２１】
室外機１１は、室外冷媒配管１９に圧縮機２０が配設され、この圧縮機２０の吸込側にアキュムレータ２１が配設され、吐出側に四方弁２３が配設され、更に、四方弁２３側の室外冷媒配管１９に室外熱交換器２４、室外電子膨張弁２５が順次配設されて構成される。また、室外熱交換器２４には、この室外熱交換器２４へ送風する室外ファン２６が隣接して配置されている。
【００２２】
この室外機１１には、三方弁のガス側閉鎖弁２７及び液側閉鎖弁２８が備えられている。これらガス側閉鎖弁２７及び液側閉鎖弁２８は、例えば、手動弁である。
【００２３】
ガス側閉鎖弁２７は、三つのポート２７Ａ、２７Ｂ、２７Ｃを有し、室外冷媒配管１９の四方弁２３側の端部１９Ａが、ガス側閉鎖弁２７のポート２７Ａに接続され、ユニット間配管１５のガス管１３の端部１３Ａがガス側閉鎖弁２７のポート２７Ｂに接続される。また、液側閉鎖弁２８は、三つのポート２８Ａ、２８Ｂ、２８Ｃを有し、室外冷媒配管１９の室外電子膨張弁２５側の端部１９Ｂが、液側閉鎖弁２８のポート２８Ａに接続され、ユニット間配管１５の液管１４の端部１４Ａが、液側閉鎖弁２８のポート２８Ｂに接続される。
【００２４】
ガス側閉鎖弁２７のポート２７Ｃ及び液側閉鎖弁２８のポート２８Ｃは、いわゆるサービスポートであり、冷媒回収や配管内のエアを抜く真空引き等を行うときに使用される。通常、ガス側閉鎖弁２７のポート２７Ａ、２７Ｂ及び液側閉鎖弁２８のポート２８Ａ、２８Ｂは、開弁されており、ガス側閉鎖弁２７のポート２７Ｃ及び液側閉鎖弁２８のポート２８Ｃは、閉弁されている。例えば、ガス側閉鎖弁２７のポート２７Ｃ及び液側閉鎖弁２８のポート２８Ｃには、虫弁（不図示）が設けられている。
【００２５】
室外機１１には、空気調和装置１０全体を制御する室外制御装置４１が設けられている。この室外制御装置４１は、圧縮機２０、四方弁２３、室外電子膨張弁２５、室外ファン２６等を制御するとともに、各室内機１２Ａ、１２Ｂの室内制御装置４２に室内電子膨張弁１７および室内ファン２２を制御するための指令を送る。
【００２６】
室外制御装置４１による四方弁２３の切換により空気調和装置１０が冷房運転又は暖房運転に設定される。冷房運転に設定された場合は、室外電子膨張弁２５が全開に制御され、暖房運転に設定された場合は、各室内機１２Ａ、１２Ｂの運転条件により室内電子膨張弁１７が適正な開度に調整（制御）される。
【００２７】
冷房運転に設定された場合、四方弁２３が冷房側に切り替えられ、冷媒が破線矢印Ａの如く流れる。そして、圧縮機２０の運転により圧縮機２０から吐出された冷媒は、四方弁２３を経て室外熱交換器２４に至り、この室外熱交換器２４で凝縮され、室外電子膨張弁２５を経て液管１４に流れ、各室内機１２Ａ、１２Ｂに分流され、これらの室内機１２Ａ、１２Ｂの室内電子膨張弁１７を経て減圧された後、室内熱交換器１８で蒸発されて室内を冷房する。各室内機１２Ａ、１２Ｂの室内熱交換器１８からの冷媒は、ガス管１３で合流し、室外機１１に流され、この室外機１１の四方弁２３及びアキュムレータ２１を経て圧縮機２０に戻される。
【００２８】
また、暖房運転に設定された場合、四方弁２３が暖房側に切り替えられ、冷媒が実線矢印Ｂの如く流れる。そして、圧縮機２０の運転により圧縮機２０から吐出された冷媒は、四方弁２３を経てガス管１３に吐出される。そして、室内機１２Ａ、１２Ｂで分流して、これら各室内機１２Ａ、１２Ｂの室内熱交換器１８にて凝縮して室内を暖房する。室内熱交換器１８にて凝縮された冷媒は室内電子膨張弁１７を経て液管１４にて合流され、室外機１１に流されて、この室外機１１の室外電子膨張弁２５で減圧され、室外熱交換器２４で蒸発された後、四方弁２３及びアキュムレータ２１を経て圧縮機２０に戻される。
【００２９】
上述のように構成された空気調和装置１０を流れる冷媒は、ＣＦＣ系やＨＣＦＣ系の冷媒（例えばＲ２２）である。この建物に既設の空気調和装置１０に代えて、ＨＦＣ系の冷媒（例えばＲ４１０Ａ、Ｒ４０７Ｃ）を用いた不図示の空気調和装置を建物に据え付ける場合、空気調和装置１０のうち室外機１１及び室内機１２Ａ、１２Ｂは新しいものに交換されるが、ユニット間配管１５は上記空気調和装置１０の既設のものが利用される。
【００３０】
この際、既設の空気調和装置１０と新設の空気調和装置とでは使用される冷媒が異なるため、これに応じて、圧縮機２０を潤滑するための冷凍機油も異なるものとなる。例えば、冷媒Ｒ２２では冷凍機油として鉱物油が使用され、冷媒Ｒ４１０ＡやＲ４０７Ｃではエーテル油やエステル油などの合成油が使用される。従って、ユニット間配管１５を再利用する際には、このユニット間配管１５内に残留する鉱物油を洗浄して除去する必要がある。
【００３１】
図１に、既設の室外機１１、室内機１２Ａ、１２Ｂ及び冷媒（例えば、Ｒ２２）を用いて、既設のユニット間配管１５を洗浄する空気調和装置の配管洗浄システム３０が示されている。つまり、室外機１１の室外冷媒配管１９とユニット間配管１５との間に配管洗浄装置３１を設置して配管洗浄システム３０を形成している。
【００３２】
この空気調和装置の配管洗浄システム３０は、既設の空気調和装置１０と、オイルセパレータ３２、キャピラリチューブ３３、及び電磁弁３４を有する配管洗浄装置３１とを備えて構成される。
【００３３】
オイルセパレータ３２は、圧縮機２０により吐出されたガス冷媒に含まれる冷凍機油としての鉱物油を分離して除去するものである。このオイルセパレータ３２は、冷媒入口３２Ａと、冷媒出口３２Ｂと、油出口３２Ｃとを備えている。そして、オイルセパレータ３２の冷媒入口３２Ａとガス側閉鎖弁２７のポート２７Ｂとは配管４３で接続される。また、オイルセパレータ３２の冷媒出口３２Ｂと電磁弁３４の一端部とは配管４４で接続される。更に、電磁弁３４の他端部とガス管１３の端部１３Ａが接続される。
【００３４】
つまり、配管洗浄装置３１のオイルセパレータ３２及び電磁弁３４は、室外機１１の室外冷媒配管１９における四方弁２３側の端部１９Ａと、ユニット間配管１５のガス管１３との間に設置されることとなる。
【００３５】
また、オイルセパレータ３２の油出口３２Ｃには、油戻し管４５の一端が接続され、油戻し管４５の他端が液管１４に接続される。この油戻し管４５には、上述のキャピラリチューブ３３が配設されている。
【００３６】
このキャピラリチューブ３３は、オイルセパレータ３２にて分離された鉱物油を室外冷媒配管１９を経て圧縮機２０へ導入し、この圧縮機２０の運転を円滑に実施させる。尚、キャピラリチューブ３３を配設した油戻し管４５は、液管１４に接続されず、圧縮機２０の吸込部に直接接続されてもよい。
【００３７】
電磁弁３４は、鉱物油が除去された冷媒のガス管１３への供給／遮断を切り替えるものである。この電磁弁３４は、室外制御装置４１によって開閉制御が行われる。
【００３８】
図３は、ユニット間配管１５を洗浄する際の手順を示すフローチャートである。
【００３９】
図３において、まず、配管洗浄装置３１を接続する前の既設の空気調和装置１０（図２）の冷房運転を行う（ステップＳ１）。
【００４０】
次いで、室外機１１に冷媒を溜め込むポンプダウン運転を行う（ステップＳ２）。このポンプダウン運転は、液側閉鎖弁２８のポート２８Ａを閉弁操作して冷房運転を行うことである。このポンプダウン運転が行われると、室内機１２Ａ、１２Ｂ及びユニット間配管１５に存在する冷媒が圧縮機２０の運転によりガス管１３を通じて圧縮機２０に吸込まれる。そして、圧縮機２０により吐出されたガス冷媒は、室外熱交換器２４で凝縮液化される。このとき、液側閉鎖弁２８が閉じられているので、液管１４に冷媒が流出することはない。このようにして、液冷媒が室外機１１の室外熱交換器２４に溜め込まれることとなる。
【００４１】
このポンプダウン運転は、例えば、５分間に亘って行い、室内機１２Ａ、１２Ｂ及びユニット間配管１５には、ほとんど冷媒がない状態になる。
【００４２】
このポンプダウン運転後、ガス側閉鎖弁２７のポート２７Ａを閉弁操作する。
【００４３】
次に、図１に示すように、室外冷媒配管１９とガス管１３との間にオイルセパレータ３２及びバルブとしての電磁弁３４を有する配管洗浄装置３１を設置する（ステップＳ３）。このポンプダウン運転の終了後は、空気調和装置１０、つまり、室外機１１及び室内機１２Ａ、１２Ｂの運転が停止している状態である。通常、空気調和装置が運転停止となる場合、室外制御装置及び室内制御装置は、室外電子膨張弁又は室内電子膨張弁のいずれか一方を全開となるように制御している。本実施の形態において、ポンプダウン運転の終了後は、室外電子膨張弁２５を全開にする制御を行っている。
【００４４】
この配管洗浄装置３１を設置する際、ユニット間配管１５、室内機１２Ａ、１２Ｂの室内冷媒配管１６、及び室内熱交換器１８には、エアが混入するので、配管洗浄装置３１を設置した後、エアを抜く真空引きを行う（ステップＳ４）。
【００４５】
つまり、図１において、ガス側閉鎖弁２７のポート２７Ｃ及び液側閉鎖弁２８のポート２８Ｃの少なくとも一方から真空引きを行う。
【００４６】
例えば、ガス側閉鎖弁２７のポート２７Ｃに図示しない真空ポンプを接続する。このとき、ガス側閉鎖弁２７のポート２７Ａ及び液側閉鎖弁２８のポート２８Ａを閉弁されている。更に、配管洗浄装置３１の電磁弁３４は開弁状態となるように制御されている。この状態で、図示しない真空ポンプの運転により、室内機１２Ａ、１２Ｂの室内冷媒配管１６及び室内熱交換器１８並びにユニット間配管１５のエアを抜く真空引きが行われる。
【００４７】
尚、ガス側閉鎖弁２７のポート２７Ｃに図示しない真空ポンプを接続した場合について説明したが、液側閉鎖弁２８のポート２８Ｃに真空ポンプを接続してもよいし、両ポート２７Ｃ、２８Ｃに真空ポンプを接続してもよい。
【００４８】
特に、複数台（図１では２台）の室内機１２Ａ、１２Ｂの室内電子膨張弁１７が開状態か閉状態か不明の場合は、前記両ポート２７Ｃ、２８Ｃ双方に真空ポンプを接続して真空引きを行うのが好ましい。
【００４９】
この真空引きは、例えば、５分間に亘って行う。真空引きが終了した場合、不図示の真空ポンプを撤去することで不図示の虫弁によりポート２７Ｃ（２８Ｃ）が閉鎖される。更に、ガス側閉鎖弁２７のポート２７Ａ及び液側閉鎖弁２８のポート２８Ａを開弁する操作を行う。
【００５０】
次に、室外機１１に設けた配管洗浄運転に移行するスイッチ（不図示）が操作された場合、室外制御装置４１は、ユニット間配管１５を洗浄するための処理に移行する。
【００５１】
まず、室外制御装置４１の制御の下、室外機１１及び室内機１２Ａ、１２Ｂの暖房運転が行われる（ステップＳ５）。この暖房運転は、予備洗浄に要する第１の所定時間（例えば、５分間）に亘って行われる。このステップＳ５では、電磁弁３４は、開弁状態であるので、ガス管１３内は、冷媒の圧力変動の少ない静圧状態となる。
【００５２】
このように配管洗浄装置３１を接続した状態で、既設の室外機１１及び室内機１２Ａ、１２Ｂの暖房運転が行われると、これら既設の室外機１１及び室内機１２Ａ、１２Ｂの冷媒は、実線矢印Ｂの如く循環する。このステップＳ５で、オイルセパレータ３２にて鉱物油が除去されたガス冷媒は、ガス管１３内を高速流動して、このガス管１３に残留した鉱物油やそのスラッジなどを除去する。また、室内熱交換器１８にて凝縮された液冷媒は、液管１４内を流れて、この液管１４内に残留した鉱物油やそのスラッジなどを除去する。つまり、オイルセパレータ３２がガス冷媒中の鉱物油を分離して除去するので、ガス管１３内は、鉱物油の存在しないガス冷媒の高速流により洗浄される。また、液管１４内は、室内熱交換器１８により凝縮された液冷媒によって洗浄される。オイルセパレータ３２で除去された鉱物油は、圧縮機２０に回収される。
【００５３】
次に、室外制御装置４１は、配管洗浄装置３１におけるバルブとしての電磁弁３４を閉鎖（閉弁操作）する（ステップＳ６）。次に、室外制御装置４１は、配管洗浄装置３１におけるバルブとしての電磁弁３４を開放（開弁操作）する（ステップＳ７）。つまり、ステップＳ６によりガス管１３へのガス冷媒の供給が遮断されてガス冷媒の圧力が高まり、ステップＳ７により電磁弁３４を開弁したときに、一気にガス冷媒がガス管１３に吐出される。ステップＳ６及びステップＳ７による開閉操作を複数回繰り返すことで、オイルセパレータ３２により鉱物油の除去された冷媒が、間欠的にガス管１３に吐出される。
【００５４】
このように、ガス冷媒が間欠的にガス管１３に吐出されることから、ガス管１３内は冷媒の圧力変動がある動圧状態となる。従って、ガス管１３内が動圧状態となるので、冷媒の圧力がほとんど変動しない静圧状態となる場合と比較してガス管１３内に残留している鉱物油が流れやすくなる。
【００５５】
ここで、ステップＳ６による電磁弁３４を閉弁する閉弁時間は、電磁弁３４を開弁したときにガス管１３に吐出される冷媒の圧力が、ガス管１３内に残留する鉱物油が流れる程度にまで上昇するように設定されている。
【００５６】
次に、電磁弁３４が開弁されている状態で、引き続き暖房運転が行われる（ステップＳ８）。このステップＳ８では、配管洗浄の仕上げに要する第２の所定期間（例えば、５分間）に亘って、更にユニット間配管１５が洗浄される。
【００５７】
ユニット間配管１５におけるガス管１３及び液管１４の洗浄終了後、図示しない冷媒回収機によって冷媒を回収する（ステップＳ９）。この冷媒回収は、ポンプダウン運転を行った後、例えば、液側閉鎖弁２８のポート２８Ｃから冷媒回収を行う。その後、室外機１１、室内機１２Ａ、１２Ｂ及び配管洗浄装置３１を撤去して（ステップＳ１０）、新しい室外機及び室内機を据え付け、これらを既設のユニット間配管１５に接続する。
【００５８】
以上、本実施の形態によれば、室外冷媒配管１９とユニット間配管１５におけるガス管１３との間にオイルセパレータ３２及び電磁弁３４を設置し、暖房運転を行い、電磁弁３４の開閉により、オイルセパレータ３２で冷凍機油としての鉱物油が除去された冷媒を、間欠的にガス管１３に吐出させ、ユニット間配管１５を冷媒で洗浄することから、ガス管１３内は冷媒の圧力変動がある動圧状態となり、冷媒の圧力がほとんど変動しない静圧状態となる場合と比較してガス管１３内の鉱物油が流れやすくなるので、特にユニット間配管１５におけるガス管１３の洗浄効果が向上する。また、ガス管１３内に動圧が作用することにより、ガス管１３内に残留している鉱物油が流れやすくなるので、洗浄に伴う時間を短縮することができ、ユニット間配管１５の洗浄効率が向上する。特に、室内機が複数台（例えば２台）のときは、ユニット間配管１５の経路が複雑となるので、ガス冷媒の動圧でより効果的にガス管１３を洗浄することができる。
【００５９】
また、本実施の形態によれば、電磁弁３４を開弁して予備洗浄に要する第１の所定時間（例えば、５分間）に亘って暖房運転を行い、第１の所定時間経過後の暖房運転中に、電磁弁３４を開閉することにより、鉱物油の除去されたガス冷媒を間欠的にガス管１３に吐出させて、ユニット間配管１５を洗浄することから、暖房運転を行った場合のガス冷媒の圧力がほとんど変動しない静圧状態で、ガス管１３内の予備洗浄が行われ、この予備洗浄で洗浄しきれずにガス管１３内に残留した鉱物油が、冷媒圧力が高められて間欠的に吐出される鉱物油の除去されたガス冷媒により洗い流されるので、特にユニット間配管１５におけるガス管１３の洗浄効果が向上する。
【００６０】
そして、万が一、ユニット間配管１５に鉱物油が残留しても、電磁弁３４の開閉操作によるユニット間配管１５の洗浄で残留する鉱物油は僅かである。また、この僅かにユニット間配管１５内に残留した鉱物油は、間欠的に吐出された冷媒によって流れやすい状態である。本実施の形態では、電磁弁３４の開閉操作後、配管洗浄の仕上げに要する第２の所定時間（例えば、５分間）に亘って暖房運転を行うようにしたことから、このユニット間配管１５内に僅かに残留した鉱物油が洗い流され、ユニット間配管１５の洗浄効果が更に向上する。
【００６１】
以上、本発明を上記実施の形態に基づいて説明したが、本発明はこれに限定されるものではない。
【００６２】
例えば、本実施の形態では、室内機が複数台の場合について説明したが、室内機の台数は任意であり、室内機が１台であってもよい。
【００６３】
また、本実施の形態では、室外冷媒配管とガス管との間にオイルセパレータとともに設置されるバルブが電磁弁であり、室外制御装置がこの電磁弁を制御する場合について説明したが、これに限るものではなく、室内制御装置が電磁弁を制御する場合であってもよいし、別途この電磁弁を制御する制御装置を設けてもよい。
【００６４】
また、本実施の形態では、室外冷媒配管とガス管との間にオイルセパレータとともに設置されるバルブが電磁弁である場合について説明したが、バルブが開閉可能な手動弁であってもよい。この場合、バルブを制御する制御装置は、省略可能である。そして、図３におけるステップＳ６では、操作者により手動でバルブとしての手動弁が閉鎖され、ステップＳ７では、操作者により手動でバルブとしての手動弁が開放される。このとき図３におけるステップＳ５及びステップＳ８では、例えば不図示のリモートコントローラ或いは室外機１１に設けた不図示のスイッチが操作者に操作されることにより暖房運転が行われる。
【００６５】
【発明の効果】
本発明によれば、ユニット間配管の洗浄効率を向上させることができる。
【図面の簡単な説明】
【図１】本発明に係る空気調和装置の配管洗浄システムにおける一実施の形態を示す系統図である。
【図２】既設の空気調和装置を示す系統図である。
【図３】ユニット間配管の洗浄を行う手順を示すフローチャートである。
【符号の説明】
１０空気調和装置
１１室外機
１２Ａ、１２Ｂ室内機
１３ガス管
１４液管
１５ユニット間配管
１６室内冷媒配管
１８室内熱交換器
１９室外冷媒配管
２０圧縮機
２４室外熱交換器
３０空気調和装置の配管洗浄システム
３１配管洗浄装置
３２オイルセパレータ
３４電磁弁（バルブ）
４１室外制御装置（制御手段、制御装置）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pipe cleaning method for an air conditioner, a pipe cleaning apparatus, a pipe cleaning system for an air conditioner, and a control device for a pipe cleaning system, which make a pipe between units installed in a building or the like usable by cleaning.
[0002]
[Prior art]
An outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and an outdoor refrigerant pipe and an indoor refrigerant pipe connected to each other; 2. Description of the Related Art There is known an air conditioner configured to include a liquid supply pipe and an inter-unit pipe having a liquid pipe.
[0003]
Among such air conditioners, when installed in a building such as a building, it is common that piping between units connecting the outdoor unit and the indoor unit is embedded in the building, and the piping length is generally longer. Further, when there are a plurality of indoor units, the interunit piping connected to these indoor units has a complicated shape with many branch pipes.
[0004]
When exchanging the outdoor unit and the indoor unit of the air conditioner, it is wasteful to replace the piping between the units installed in the building if the life of the piping between the units has a margin, and it is effective. Should be used.
[0005]
However, when the refrigerant used between the existing air conditioner and the new air conditioner is different, the refrigerating machine oil is also different corresponding to these refrigerants. Therefore, when exchanging the outdoor unit and the indoor unit while leaving the piping between the units of the existing air conditioner, it is necessary to remove the refrigerating machine oil remaining in the fixed piping between the units.
[0006]
Conventionally, for the existing air conditioner, the outdoor unit and the indoor unit are newly replaced, and the piping between the units connecting the outdoor unit and the indoor unit is not replaced. 2. Description of the Related Art There is known a device provided with a means for capturing foreign matter such as refrigerating machine oil from a circulating refrigerant (for example, see Patent Document 1).
[0007]
[Patent Document 1]
JP 2000-9368 A
[0008]
[Problems to be solved by the invention]
In the above-described air conditioner for cleaning the piping between the units, the liquid refrigerant flows in the liquid piping of the piping between the units, so that the refrigerating machine oil in the liquid piping flows easily and can be cleaned well. However, since the gas refrigerant flows in the gas pipe of the unit-to-unit pipe, the refrigerating machine oil hardly flows and tends to remain. Then, in order to remove the refrigerating machine oil in the gas pipes satisfactorily, the operation for cleaning takes a long time, which is not efficient.
[0009]
An object of the present invention has been made in consideration of the above circumstances, and a method of cleaning a pipe of an air conditioner, a pipe cleaning apparatus, a pipe cleaning system of an air conditioner, and a method of improving the cleaning efficiency of inter-unit pipes. A control device for a pipe cleaning system is provided.
[0010]
[Means for Solving the Problems]
To solve the above problems, an outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, the outdoor refrigerant pipe, In the method for cleaning a pipe of an air conditioner, comprising connecting an indoor refrigerant pipe, and an inter-unit pipe comprising a gas pipe and a liquid pipe, the compressor is operated, and the air conditioner is connected between the outdoor refrigerant pipe and the gas pipe. An oil removing step of removing refrigeration oil contained in the gas refrigerant discharged from the compressor, and intermittently discharging the refrigerant from which the refrigeration oil has been removed to the gas pipe, thereby forming And a washing step of washing with (1).
[0011]
Also, an outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and the outdoor refrigerant pipe and the indoor refrigerant pipe are connected. And a pipe cleaning method for an air conditioner having a gas pipe and an inter-unit pipe comprising a liquid pipe, wherein a heating operation is performed, and between the outdoor refrigerant pipe and the gas pipe, the air is discharged from the compressor. An oil removing step of removing the refrigerating machine oil contained in the gas refrigerant, and a washing step of intermittently discharging the refrigerant from which the refrigerating machine oil has been removed to the gas pipe and washing the inter-unit piping with the refrigerant. It is characterized by having.
[0012]
Also, an outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and the outdoor refrigerant pipe and the indoor refrigerant pipe are connected. A pipe cleaning device installed in an air conditioner having a gas pipe and a liquid pipe provided between units, wherein an oil separator and a valve are installed between the outdoor refrigerant pipe and the gas pipe. Wherein the refrigerant discharged from the compressor and from which the refrigerating machine oil has been removed by the oil separator is intermittently discharged into the gas pipe by opening and closing the valve, and the interunit piping is washed with the refrigerant. It is assumed that.
[0013]
Also, an outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and the outdoor refrigerant pipe and the indoor refrigerant pipe are connected. And an inter-unit pipe comprising a gas pipe and a liquid pipe, in a pipe cleaning system of an air conditioner, wherein the gas refrigerant discharged from the compressor is provided between the outdoor refrigerant pipe and the gas pipe. Oil removing means for removing the included refrigerating machine oil, and switching means for switching between supply and cutoff of the refrigerant from which the refrigerating machine oil has been removed to the gas pipe, and intermittently discharging the refrigerant to the gas pipe. Thus, the inter-unit piping is cleaned.
[0014]
In this case, control means for controlling the switching means may be provided.
[0015]
Also, an outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and the outdoor refrigerant pipe and the indoor refrigerant pipe are connected. And an inter-unit pipe comprising a gas pipe and a liquid pipe, and a pipe cleaning system for an air conditioner, comprising: an oil separator and a valve between the outdoor refrigerant pipe and the gas pipe to perform a heating operation. Then, by opening and closing the valve, the refrigerant from which the refrigerating machine oil has been removed by the oil separator is intermittently discharged to the gas pipe, and the interunit piping is washed with the refrigerant.
[0016]
Also, an outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and the outdoor refrigerant pipe and the indoor refrigerant pipe are connected. And, in the control device of the pipe cleaning system of the air conditioner having a gas pipe and an inter-unit pipe having a liquid pipe, the compressor is discharged from the compressor between the outdoor refrigerant pipe and the gas pipe. An oil separator and a valve for removing the refrigeration oil contained in the gas refrigerant are installed, and a heating operation is performed, and by controlling the opening and closing of the valve, the refrigerant from which the refrigeration oil has been removed by the oil separator is intermittently supplied. The gas is discharged to the gas pipe, and the inter-unit pipe is washed with a refrigerant.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
FIG. 1 is a system diagram showing one embodiment of a pipe cleaning system for an air conditioner according to the present invention.
[0019]
FIG. 2 shows the existing air conditioner 10 before the pipe cleaning device 31 is attached. In this air conditioner 10, an outdoor unit 11 is connected to an inter-unit pipe 15 including a gas pipe 13 and a liquid pipe 14, and a plurality (two in FIG. 2) of indoor units 12A and 12B are arranged in parallel. It is connected to and configured.
[0020]
The indoor units 12A and 12B are configured by arranging an indoor electronic expansion valve 17 and an indoor heat exchanger 18 in an indoor refrigerant pipe 16, one end of the indoor refrigerant pipe 16 is connected to the gas pipe 13, and the other end is connected to the indoor electronic expansion valve. 17 are connected to the liquid tubes 14 respectively. An indoor fan 22 that blows air to the indoor heat exchanger 18 is disposed adjacent to the indoor heat exchanger 18. Further, the indoor units 12A and 12B are provided with an indoor control device 42 for controlling the indoor electronic expansion valve 17 and the indoor fan 22. The degree of opening of the indoor electronic expansion valve 17 is adjusted by the indoor control device 42 according to the air conditioning load.
[0021]
In the outdoor unit 11, a compressor 20 is disposed in an outdoor refrigerant pipe 19, an accumulator 21 is disposed on a suction side of the compressor 20, a four-way valve 23 is disposed on a discharge side, and further, a four-way valve 23 side. , An outdoor heat exchanger 24 and an outdoor electronic expansion valve 25 are sequentially arranged in the outdoor refrigerant pipe 19. An outdoor fan 26 that blows air to the outdoor heat exchanger 24 is disposed adjacent to the outdoor heat exchanger 24.
[0022]
The outdoor unit 11 is provided with a gas-side shutoff valve 27 and a liquid-side shutoff valve 28, which are three-way valves. The gas side stop valve 27 and the liquid side stop valve 28 are, for example, manual valves.
[0023]
The gas-side shut-off valve 27 has three ports 27A, 27B, and 27C. An end 19A of the outdoor refrigerant pipe 19 on the four-way valve 23 side is connected to the port 27A of the gas-side shut-off valve 27. Of the gas pipe 13 is connected to the port 27B of the gas-side shut-off valve 27. The liquid-side stop valve 28 has three ports 28A, 28B, and 28C, and an end 19B of the outdoor refrigerant pipe 19 on the side of the outdoor electronic expansion valve 25 is connected to the port 28A of the liquid-side stop valve 28. An end 14A of the liquid pipe 14 of the unit-to-unit pipe 15 is connected to a port 28B of the liquid side closing valve 28.
[0024]
The port 27C of the gas-side shut-off valve 27 and the port 28C of the liquid-side shut-off valve 28 are so-called service ports, and are used when performing refrigerant recovery or evacuating to remove air from the piping. Normally, the ports 27A and 27B of the gas side closing valve 27 and the ports 28A and 28B of the liquid side closing valve 28 are opened, and the port 27C of the gas side closing valve 27 and the port 28C of the liquid side closing valve 28 are The valve has been closed. For example, a worm valve (not shown) is provided in the port 27C of the gas-side stop valve 27 and the port 28C of the liquid-side stop valve 28.
[0025]
The outdoor unit 11 is provided with an outdoor control device 41 that controls the entire air conditioner 10. The outdoor control device 41 controls the compressor 20, the four-way valve 23, the outdoor electronic expansion valve 25, the outdoor fan 26, and the like, and also controls the indoor electronic expansion valve 17 and the indoor fan in the indoor control devices 42 of the indoor units 12A and 12B. 22 to send a command to control 22.
[0026]
The air conditioner 10 is set to the cooling operation or the heating operation by switching the four-way valve 23 by the outdoor control device 41. When the cooling operation is set, the outdoor electronic expansion valve 25 is controlled to be fully opened, and when the heating operation is set, the indoor electronic expansion valve 17 is set to an appropriate opening according to the operating conditions of the indoor units 12A and 12B. It is adjusted (controlled).
[0027]
When the cooling operation is set, the four-way valve 23 is switched to the cooling side, and the refrigerant flows as indicated by a dashed arrow A. The refrigerant discharged from the compressor 20 by the operation of the compressor 20 reaches the outdoor heat exchanger 24 via the four-way valve 23, is condensed in the outdoor heat exchanger 24, passes through the outdoor electronic expansion valve 25, and flows through the liquid pipe. 14, the air is diverted to the indoor units 12A and 12B, the pressure is reduced through the indoor electronic expansion valves 17 of the indoor units 12A and 12B, and then the air is evaporated by the indoor heat exchanger 18 to cool the room. Refrigerant from the indoor heat exchanger 18 of each of the indoor units 12A and 12B joins in the gas pipe 13, flows into the outdoor unit 11, and returns to the compressor 20 via the four-way valve 23 and the accumulator 21 of the outdoor unit 11. .
[0028]
When the heating operation is set, the four-way valve 23 is switched to the heating side, and the refrigerant flows as indicated by the solid arrow B. Then, the refrigerant discharged from the compressor 20 by the operation of the compressor 20 is discharged to the gas pipe 13 through the four-way valve 23. Then, the air is divided by the indoor units 12A and 12B, and condensed by the indoor heat exchangers 18 of the indoor units 12A and 12B to heat the room. The refrigerant condensed in the indoor heat exchanger 18 passes through the indoor electronic expansion valve 17, joins in the liquid pipe 14, flows into the outdoor unit 11, is decompressed by the outdoor electronic expansion valve 25 of the outdoor unit 11, and After being evaporated in the heat exchanger 24, it is returned to the compressor 20 via the four-way valve 23 and the accumulator 21.
[0029]
The refrigerant flowing through the air-conditioning apparatus 10 configured as described above is a CFC-based or HCFC-based refrigerant (for example, R22). When an air conditioner (not shown) using an HFC-based refrigerant (for example, R410A, R407C) is installed in the building instead of the existing air conditioner 10 in the building, the outdoor unit 11 and the indoor unit of the air conditioner 10 are installed. Although 12A and 12B are replaced with new ones, the existing unit of the air conditioner 10 is used as the unit-to-unit piping 15.
[0030]
At this time, since the refrigerant used differs between the existing air conditioner 10 and the new air conditioner, the refrigerating machine oil for lubricating the compressor 20 is also different accordingly. For example, the refrigerant R22 uses mineral oil as the refrigerating machine oil, and the refrigerants R410A and R407C use synthetic oils such as ether oil and ester oil. Therefore, when reusing the inter-unit piping 15, it is necessary to wash and remove the mineral oil remaining in the inter-unit piping 15.
[0031]
FIG. 1 shows a piping cleaning system 30 of an air conditioner that cleans an existing inter-unit piping 15 using an existing outdoor unit 11, indoor units 12A and 12B, and a refrigerant (for example, R22). That is, the pipe cleaning device 31 is installed between the outdoor refrigerant pipe 19 of the outdoor unit 11 and the inter-unit pipe 15 to form the pipe cleaning system 30.
[0032]
The pipe cleaning system 30 of the air conditioner includes the existing air conditioner 10 and a pipe cleaning device 31 having an oil separator 32, a capillary tube 33, and a solenoid valve.
[0033]
The oil separator 32 separates and removes mineral oil as refrigeration oil contained in the gas refrigerant discharged from the compressor 20. The oil separator 32 has a refrigerant inlet 32A, a refrigerant outlet 32B, and an oil outlet 32C. The refrigerant inlet 32A of the oil separator 32 and the port 27B of the gas-side shut-off valve 27 are connected by a pipe 43. The refrigerant outlet 32B of the oil separator 32 and one end of the solenoid valve 34 are connected by a pipe 44. Further, the other end of the solenoid valve 34 and the end 13A of the gas pipe 13 are connected.
[0034]
That is, the oil separator 32 and the solenoid valve 34 of the pipe cleaning device 31 are installed between the end 19A of the outdoor refrigerant pipe 19 of the outdoor unit 11 on the four-way valve 23 side and the gas pipe 13 of the inter-unit pipe 15. It will be.
[0035]
Further, one end of an oil return pipe 45 is connected to the oil outlet 32 C of the oil separator 32, and the other end of the oil return pipe 45 is connected to the liquid pipe 14. The above-described capillary tube 33 is provided in the oil return pipe 45.
[0036]
The capillary tube 33 introduces the mineral oil separated by the oil separator 32 into the compressor 20 via the outdoor refrigerant pipe 19, and smoothly operates the compressor 20. Note that the oil return pipe 45 provided with the capillary tube 33 may not be connected to the liquid pipe 14 but may be directly connected to the suction part of the compressor 20.
[0037]
The solenoid valve 34 switches supply / cutoff of the refrigerant from which the mineral oil has been removed to the gas pipe 13. The opening and closing control of the electromagnetic valve 34 is performed by the outdoor control device 41.
[0038]
FIG. 3 is a flowchart showing a procedure for cleaning the inter-unit piping 15.
[0039]
In FIG. 3, first, the cooling operation of the existing air conditioner 10 (FIG. 2) before connecting the pipe cleaning device 31 is performed (step S1).
[0040]
Next, a pump-down operation for storing the refrigerant in the outdoor unit 11 is performed (step S2). This pump-down operation is to perform a cooling operation by closing the port 28A of the liquid side closing valve 28. When the pump-down operation is performed, the refrigerant existing in the indoor units 12A and 12B and the inter-unit piping 15 is sucked into the compressor 20 through the gas pipe 13 by the operation of the compressor 20. Then, the gas refrigerant discharged from the compressor 20 is condensed and liquefied in the outdoor heat exchanger 24. At this time, since the liquid side closing valve 28 is closed, the refrigerant does not flow out to the liquid pipe 14. In this way, the liquid refrigerant is stored in the outdoor heat exchanger 24 of the outdoor unit 11.
[0041]
This pump-down operation is performed, for example, for five minutes, and the indoor units 12A and 12B and the unit-to-unit piping 15 have almost no refrigerant.
[0042]
After this pump-down operation, the port 27A of the gas-side closing valve 27 is closed.
[0043]
Next, as shown in FIG. 1, a pipe cleaning device 31 having an oil separator 32 and an electromagnetic valve 34 as a valve is installed between the outdoor refrigerant pipe 19 and the gas pipe 13 (Step S3). After the end of the pump-down operation, the operation of the air conditioner 10, that is, the operation of the outdoor unit 11 and the indoor units 12A and 12B is stopped. Normally, when the operation of the air conditioner is stopped, the outdoor control device and the indoor control device control one of the outdoor electronic expansion valve and the indoor electronic expansion valve to be fully opened. In the present embodiment, after the pump-down operation is completed, control for fully opening the outdoor electronic expansion valve 25 is performed.
[0044]
When installing the pipe cleaning device 31, since air is mixed into the unit-to-unit pipe 15, the indoor refrigerant pipe 16 of the indoor units 12 A and 12 B, and the indoor heat exchanger 18, after installing the pipe cleaning device 31, A vacuum is drawn to remove air (step S4).
[0045]
That is, in FIG. 1, vacuum is drawn from at least one of the port 27C of the gas-side stop valve 27 and the port 28C of the liquid-side stop valve 28.
[0046]
For example, a vacuum pump (not shown) is connected to the port 27C of the gas side closing valve 27. At this time, the port 27A of the gas side closing valve 27 and the port 28A of the liquid side closing valve 28 are closed. Further, the solenoid valve 34 of the pipe cleaning device 31 is controlled to be in an open state. In this state, the vacuum pump (not shown) operates to evacuate the indoor refrigerant pipes 16 and the indoor heat exchangers 18 of the indoor units 12A and 12B and the air from the unit-to-unit pipes 15 to evacuate.
[0047]
Although a case has been described in which a vacuum pump (not shown) is connected to the port 27C of the gas side closing valve 27, a vacuum pump may be connected to the port 28C of the liquid side closing valve 28, or a vacuum may be connected to both ports 27C and 28C. A pump may be connected.
[0048]
In particular, when it is unclear whether the indoor electronic expansion valves 17 of the plurality of (two in FIG. 1) indoor units 12A and 12B are in the open state or the closed state, a vacuum pump is connected to both the ports 27C and 28C to evacuate the vacuum. Preferably, a pull is performed.
[0049]
This evacuation is performed, for example, for 5 minutes. When the evacuation is completed, the port 27C (28C) is closed by the insect valve (not shown) by removing the vacuum pump (not shown). Further, an operation of opening the port 27A of the gas side stop valve 27 and the port 28A of the liquid side stop valve 28 is performed.
[0050]
Next, when a switch (not shown) for shifting to the pipe cleaning operation provided in the outdoor unit 11 is operated, the outdoor control device 41 shifts to a process for cleaning the inter-unit pipe 15.
[0051]
First, the heating operation of the outdoor unit 11 and the indoor units 12A and 12B is performed under the control of the outdoor control device 41 (step S5). This heating operation is performed for a first predetermined time (for example, 5 minutes) required for the preliminary cleaning. In this step S5, since the solenoid valve 34 is in the open state, the inside of the gas pipe 13 is in a static pressure state in which the pressure fluctuation of the refrigerant is small.
[0052]
When the heating operation of the existing outdoor unit 11 and the indoor units 12A and 12B is performed in a state where the pipe cleaning device 31 is connected as described above, the refrigerant of the existing outdoor unit 11 and the indoor units 12A and 12B is solid arrows. Circulates as B. In step S5, the gas refrigerant from which the mineral oil has been removed by the oil separator 32 flows through the gas pipe 13 at high speed to remove the mineral oil remaining in the gas pipe 13 and its sludge. The liquid refrigerant condensed in the indoor heat exchanger 18 flows through the liquid pipe 14 to remove mineral oil, sludge, and the like remaining in the liquid pipe 14. That is, since the oil separator 32 separates and removes the mineral oil in the gas refrigerant, the inside of the gas pipe 13 is washed by the high-speed flow of the gas refrigerant without the mineral oil. The inside of the liquid pipe 14 is washed by the liquid refrigerant condensed by the indoor heat exchanger 18. The mineral oil removed by the oil separator 32 is collected by the compressor 20.
[0053]
Next, the outdoor control device 41 closes (closes) the electromagnetic valve 34 as a valve in the pipe cleaning device 31 (step S6). Next, the outdoor control device 41 opens (opens the valve) the electromagnetic valve 34 as a valve in the pipe cleaning device 31 (step S7). That is, the supply of the gas refrigerant to the gas pipe 13 is interrupted in step S6, and the pressure of the gas refrigerant increases. When the solenoid valve 34 is opened in step S7, the gas refrigerant is discharged to the gas pipe 13 at a stretch. By repeating the opening and closing operations in steps S6 and S7 a plurality of times, the refrigerant from which the mineral oil has been removed by the oil separator 32 is intermittently discharged to the gas pipe 13.
[0054]
Since the gas refrigerant is intermittently discharged to the gas pipe 13 in this manner, the inside of the gas pipe 13 is in a dynamic pressure state in which the pressure of the refrigerant fluctuates. Therefore, since the inside of the gas pipe 13 is in a dynamic pressure state, the mineral oil remaining in the gas pipe 13 is more likely to flow than in a case where the refrigerant pressure is in a static pressure state in which there is almost no change.
[0055]
Here, during the valve closing time in which the electromagnetic valve 34 is closed in step S6, the pressure of the refrigerant discharged to the gas pipe 13 when the electromagnetic valve 34 is opened causes the mineral oil remaining in the gas pipe 13 to flow. It is set to rise to the extent.
[0056]
Next, the heating operation is continuously performed with the electromagnetic valve 34 being opened (step S8). In this step S8, the interunit piping 15 is further cleaned for a second predetermined period (for example, 5 minutes) required for finishing the cleaning of the piping.
[0057]
After the cleaning of the gas pipe 13 and the liquid pipe 14 in the inter-unit pipe 15 is completed, the refrigerant is recovered by a refrigerant recovery device (not shown) (Step S9). In this refrigerant recovery, after the pump down operation is performed, for example, the refrigerant is recovered from the port 28C of the liquid side closing valve 28. Thereafter, the outdoor unit 11, the indoor units 12A and 12B, and the pipe cleaning device 31 are removed (step S10), and a new outdoor unit and an indoor unit are installed, and these are connected to the existing unit-to-unit piping 15.
[0058]
As described above, according to the present embodiment, the oil separator 32 and the solenoid valve 34 are installed between the outdoor refrigerant pipe 19 and the gas pipe 13 in the unit-to-unit pipe 15, and a heating operation is performed. The refrigerant from which the mineral oil as the refrigerating machine oil has been removed by the oil separator 32 is intermittently discharged into the gas pipe 13 and the inter-unit piping 15 is washed with the refrigerant. Since the mineral oil in the gas pipe 13 is more likely to flow than in the case of a dynamic pressure state and a static pressure state in which the pressure of the refrigerant hardly fluctuates, the cleaning effect of the gas pipe 13 on the inter-unit pipe 15 is particularly improved. . Further, the dynamic pressure acts on the gas pipe 13, so that the mineral oil remaining in the gas pipe 13 flows easily, so that the time required for cleaning can be shortened, and the cleaning efficiency of the inter-unit piping 15 can be reduced. Is improved. In particular, when the number of indoor units is two or more (for example, two), the path of the inter-unit pipe 15 becomes complicated, so that the gas pipe 13 can be more effectively cleaned with the dynamic pressure of the gas refrigerant.
[0059]
Further, according to the present embodiment, the heating operation is performed for the first predetermined time (for example, 5 minutes) required for the preliminary cleaning by opening the electromagnetic valve 34, and the heating operation after the first predetermined time has elapsed. During operation, by opening and closing the solenoid valve 34, the gas refrigerant from which the mineral oil has been removed is intermittently discharged into the gas pipe 13 to clean the unit-to-unit pipe 15, so that the heating operation is performed. Preliminary cleaning of the gas pipe 13 is performed in a static pressure state in which the pressure of the gas refrigerant hardly fluctuates. Mineral oil remaining in the gas pipe 13 that cannot be completely cleaned by the preliminary cleaning is intermittently increased by increasing the refrigerant pressure. Since the gas refrigerant from which the mineral oil is discharged is washed away, the cleaning effect of the gas pipe 13 in the inter-unit pipe 15 is particularly improved.
[0060]
Even if the mineral oil remains in the inter-unit piping 15, only a small amount of the mineral oil remains when the inter-unit piping 15 is washed by opening and closing the solenoid valve 34. Further, the mineral oil slightly remaining in the inter-unit pipe 15 is in a state where it is likely to flow due to the intermittently discharged refrigerant. In the present embodiment, after the opening and closing operation of the electromagnetic valve 34, the heating operation is performed for a second predetermined time (for example, 5 minutes) required for finishing the pipe cleaning. Mineral oil slightly remaining is washed away, and the cleaning effect of the interunit piping 15 is further improved.
[0061]
As described above, the present invention has been described based on the above embodiment, but the present invention is not limited to this.
[0062]
For example, in the present embodiment, a case has been described in which a plurality of indoor units are provided. However, the number of indoor units is arbitrary, and one indoor unit may be used.
[0063]
Further, in the present embodiment, a case is described in which the valve installed together with the oil separator between the outdoor refrigerant pipe and the gas pipe is a solenoid valve, and the outdoor control device controls the solenoid valve, but the present invention is not limited to this. Instead, the indoor control device may control the electromagnetic valve, or a separate control device for controlling the electromagnetic valve may be provided.
[0064]
Further, in the present embodiment, a case has been described in which the valve installed together with the oil separator between the outdoor refrigerant pipe and the gas pipe is an electromagnetic valve, but a manual valve that can be opened and closed may be used. In this case, the control device for controlling the valve can be omitted. Then, in step S6 in FIG. 3, the operator manually closes the manual valve as a valve, and in step S7, the operator manually opens the manual valve as a valve. At this time, in steps S5 and S8 in FIG. 3, for example, a heating operation is performed by an operator operating a not-shown remote controller or a switch (not shown) provided in the outdoor unit 11.
[0065]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the cleaning efficiency of the piping between units can be improved.
[Brief description of the drawings]
FIG. 1 is a system diagram showing one embodiment of a pipe cleaning system for an air conditioner according to the present invention.
FIG. 2 is a system diagram showing an existing air conditioner.
FIG. 3 is a flowchart showing a procedure for cleaning the piping between units.
[Explanation of symbols]
10 Air conditioner
11 outdoor units
12A, 12B indoor unit
13 Gas pipe
14 liquid tubes
15 Unit piping
16 Indoor refrigerant piping
18 Indoor heat exchanger
19 Outdoor refrigerant piping
20 Compressor
24 outdoor heat exchanger
30 Air conditioner piping cleaning system
31 Piping cleaning device
32 oil separator
34 Solenoid valve (valve)
41 Outdoor control device (control means, control device)

Claims

An outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and connecting the outdoor refrigerant pipe and the indoor refrigerant pipe, A pipe between units comprising a gas pipe and a liquid pipe; and
Operating the compressor, between the outdoor refrigerant pipe and the gas pipe, an oil removal step of removing refrigeration oil contained in the gas refrigerant discharged from the compressor,
A cleaning step of intermittently discharging the refrigerant from which the refrigerating machine oil has been removed to the gas pipe and cleaning the inter-unit pipe with the refrigerant.

An outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and connecting the outdoor refrigerant pipe and the indoor refrigerant pipe, A pipe between units comprising a gas pipe and a liquid pipe; and
Heating operation, between the outdoor refrigerant pipe and the gas pipe, an oil removal step of removing refrigeration oil contained in the gas refrigerant discharged from the compressor,
A cleaning step of intermittently discharging the refrigerant from which the refrigerating machine oil has been removed to the gas pipe and cleaning the inter-unit pipe with the refrigerant.

An outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and connecting the outdoor refrigerant pipe and the indoor refrigerant pipe, In a pipe cleaning device installed in an air conditioner having a gas pipe and an inter-unit pipe comprising a liquid pipe,
It is installed between the outdoor refrigerant pipe and the gas pipe, has an oil separator and a valve, and intermittently operates the refrigerant discharged from the compressor from which the refrigerating machine oil has been removed by the oil separator by opening and closing the valve. A pipe cleaning device, wherein the pipe is discharged into the gas pipe and the inter-unit pipe is cleaned with a refrigerant.

An outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and connecting the outdoor refrigerant pipe and the indoor refrigerant pipe, A pipe cleaning system for an air conditioner, comprising: an inter-unit pipe comprising a gas pipe and a liquid pipe;
Oil removing means for removing refrigeration oil contained in gas refrigerant discharged from the compressor, between the outdoor refrigerant pipe and the gas pipe,
Switching means for switching supply / shutoff of the refrigerant from which the refrigerating machine oil has been removed to the gas pipe,
A pipe cleaning system for an air conditioner, wherein the pipe between the units is cleaned by intermittently discharging the refrigerant to the gas pipe.

The piping cleaning system for an air conditioner according to claim 4,
A piping cleaning system for an air conditioner, comprising a control unit for controlling the switching unit.

An outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and connecting the outdoor refrigerant pipe and the indoor refrigerant pipe, A pipe cleaning system for an air conditioner, comprising: an inter-unit pipe comprising a gas pipe and a liquid pipe;
An oil separator and a valve are provided between the outdoor refrigerant pipe and the gas pipe, a heating operation is performed, and the refrigerant from which the refrigerating machine oil has been removed by the oil separator is opened and closed by intermittently supplying the gas pipe with the gas pipe. And cleaning the piping between the units with a refrigerant.

An outdoor unit in which a compressor and an outdoor heat exchanger are disposed in an outdoor refrigerant pipe, an indoor unit in which an indoor heat exchanger is disposed in an indoor refrigerant pipe, and connecting the outdoor refrigerant pipe and the indoor refrigerant pipe, In a control device of a pipe cleaning system of an air conditioner having a pipe between units including a gas pipe and a liquid pipe,
An oil separator and a valve are provided between the outdoor refrigerant pipe and the gas pipe to remove refrigerating machine oil contained in gas refrigerant discharged from the compressor,
By performing a heating operation and performing control to open and close the valve, the refrigerant from which the refrigerating machine oil has been removed by the oil separator is intermittently discharged to the gas pipe, and the inter-unit piping is washed with the refrigerant. A control device for a piping cleaning system of an air conditioner, characterized in that: