JP3799947B2 - Refrigeration and air conditioning equipment - Google Patents

Refrigeration and air conditioning equipment Download PDF

Info

Publication number
JP3799947B2
JP3799947B2 JP2000092852A JP2000092852A JP3799947B2 JP 3799947 B2 JP3799947 B2 JP 3799947B2 JP 2000092852 A JP2000092852 A JP 2000092852A JP 2000092852 A JP2000092852 A JP 2000092852A JP 3799947 B2 JP3799947 B2 JP 3799947B2
Authority
JP
Japan
Prior art keywords
refrigerant
liquid
pipe
refrigeration
gas
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
JP2000092852A
Other languages
Japanese (ja)
Other versions
JP2001280763A (en
Inventor
修 森本
智彦 河西
博文 高下
史武 畝崎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP2000092852A priority Critical patent/JP3799947B2/en
Publication of JP2001280763A publication Critical patent/JP2001280763A/en
Application granted granted Critical
Publication of JP3799947B2 publication Critical patent/JP3799947B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/18—Refrigerant conversion

Landscapes

  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Description

【０００１】
【発明の属する技術分野】
この発明は、前の冷媒、冷凍機油（第１の冷媒、冷凍機油）で使用した既設の延長配管および既設の負荷側熱交換器のうち少なくとも一方を再使用する冷凍・空調装置に関し、該冷凍・空調装置を新たに使用する冷媒、冷凍機油（第２の冷媒、冷凍機油）の冷媒で洗浄して使用するようにした冷凍・空調装置に関するものである。
【０００２】
【従来の技術】
図３０、特開平11‐083247号公報に記載の既設の延長配管（既設の配管）の洗浄方法を示す図である。図３０において、１は圧縮機、２はサブ熱交換器、３は四方弁、４ａは第一搬送熱交換器、４ｂは第二搬送熱交換器、５ａ〜５ｄはブリッジ整流回路、６は感温式膨張弁、７は熱交換器であり、これらを接続して熱ポンプ回路１０３を構成する。また、８は異物分離器、９ａ〜９ｄは逆止弁、１０、１１、１２は開閉弁、１０１は既設の液管、１０２は既設のガス管、１３はタンクであり、これらにより洗浄回路１０４を構成する。
【０００３】
既設の液管１０１および既設のガス管１０２を洗浄する動作について説明する。四方弁３を実線の向きにした後、圧縮機１を起動する。圧縮機１を吐出した高温の冷媒ガスは、サブ熱交換器２にてある熱量を放熱し、四方弁３を介して第一搬送熱交換器４ａで凝縮する。この凝縮した冷媒液もしくは気液二相冷媒は、ブリッジ回路５ａを流れて異物分離器８内の熱交換器７に至る。冷媒は熱交換器７を流れる際に、洗浄回路中を流れ回収した異物を含む洗浄剤を加熱・蒸発させるとともに、自身は冷却されて過冷却した液冷媒となる。この液冷媒は感温式膨張弁６で低圧まで絞られて低温の気液二相状態となり、ブリッジ回路５ｃを流れて第二搬送熱交換器４ｂを流れ蒸発・気化し、四方弁３を介して圧縮機１へ戻る。
【０００４】
以上のように冷媒が熱ポンプ回路１０３上を流れた場合には、洗浄回路１０４において、第二搬送熱交換器４ｂ内には洗浄剤が凝縮液化し、やがて第二搬送熱交換器内は洗浄液で満たされるようになる。この時、熱ポンプ回路１０３上では、第二搬送熱交換器４ｂ内で蒸発しきれなかった液冷媒が圧縮機１へ吸入されて、吐出温度が低下するので、この温度低下が所定値以下になった場合には、四方弁３を破線の向きに切り替える。
【０００５】
四方弁３が破線の向きに切り替わった場合の熱ポンプ回路１０３の冷媒の流れについて説明する。圧縮機１を吐出した高温の冷媒は、サブ熱交換器２である熱量を放熱し、四方弁３を介して第二搬送熱交換器４ｂで凝縮する。この凝縮した冷媒液もしくは気液二相冷媒は、ブリッジ回路５ｄを流れて異物分離器８内の熱交換器７に至る。冷媒は熱交換器７を流れる際に、洗浄回路中を流れ回収した異物を含む洗浄剤を加熱・蒸発させるとともに、自身は冷却されて過冷却した液冷媒となる。この液冷媒は感温式膨張弁６で低圧まで絞られて低温の気液二相状態となり、ブリッジ回路５ｂを流れて第一搬送熱交換器４ａを流れ蒸発・気化し、四方弁３を介して圧縮機１へ戻る。
【０００６】
ここで、洗浄回路１０４では、第二搬送熱交換器４ｂ内の洗浄剤が加熱され一部気化し、洗浄液が逆止弁９ｄを介して第二搬送熱交換器４ｂから流出する。流出した洗浄液は液管１０１およびガス管１０２を流れると共に、該配管中の鉱油等の異物を溶解し、異物分離器８に流入する。異物を溶解した洗浄液は、熱交換器７から吸熱して気化し異物を分離後、低温となっている第一搬送熱交換器４ａ内で凝縮・液化する。
【０００７】
かかる動作によって、第一搬送熱交換器４ａと第二搬送熱交換器４ｂとが交互に洗浄液を溜める動作と洗浄液を放出する動作を所定の間繰返し行い、既設の液管１０１およびガス管１０２を洗浄する。洗浄運転後は、洗浄液をタンク１３に回収し、洗浄を終了する。
【０００８】
【発明が解決しようとする課題】
かかる構成の洗浄方法は、配管内を完全に洗浄剤で満たすため、洗浄剤を多量に準備する必要がある。特に、クロロフルオロカーボン系（CFC系）冷媒やハイドロクロロフルオロカーボン系（HCFC系）冷媒の冷凍機油として用いられる鉱油を洗浄するためには、HCFC系の洗浄剤を用いる必要があり、環境上、問題がある。また、配管内に液状態で存在する洗浄剤を概ね回収する場合でも、洗浄剤の回収に時間がかかる。また、１台の室外ユニットに対し、複数の室内ユニットを接続するマルチ型冷凍・空調装置では、洗浄の際に、洗浄剤を前記各室内ユニットと接続する冷媒配管の１本ずつに流すための流量制御手段がなく、前記各室内ユニットの高低差、接続配管長のアンバランスによって、前記各室内ユニットの接続配管の洗浄が不十分になる可能性があるという課題があった。
【０００９】
この発明は、前記の問題点を解消するためになされたものであり、既設配管や既設室内ユニットを用いる冷凍・空調装置において、既設配管や既設室内ユニットの洗浄に関し、環境に配慮しつつ、洗浄剤の回収の必要がなく、制御が容易であり、洗浄効率の高い、洗浄が迅速で、さらに、洗浄の信頼性が高い冷凍・空調装置を得ることを目的とする。
【００１０】
【課題を解決するための手段】
この発明に係る冷凍・空調装置は、圧縮機、熱源側熱交換器等により構成される室外機ユニットと、複数の負荷側熱交換器等により構成される室内機ユニットと、前記室内機ユニットもしくは前記室外機ユニットの少なくとも一方に設けた絞り装置と、前記室外機ユニットと前記室内機ユニットを接続する液管、ガス管と、を備え、前記液管及び前記ガス管、並びに前記室内機ユニットのうち少なくとも一方が第1の冷媒、冷凍機油で使用したものの再使用であるものであり、前記第１の冷媒、冷凍機油とは相違する第２の冷媒、冷凍機油を使用するに際して、制御手段により、前記第２の冷媒を液もしくは気液二相とし、該液もしくは気液二相の第２の冷媒で前記再使用部分を洗浄するとともに、前記複数の負荷側熱交換器の接続配管である枝管は、１本ずつ、液もしくは気液二相冷媒を順次流して洗浄するものである。
ことを特徴とする。
【００１１】
本発明の請求項２に関わる冷凍・空調装置は、請求項１の冷凍・空調装置において、異物回収器と冷媒熱交換器を有する洗浄回路を備えたものである。
【００１２】
本発明の請求項３に関わる冷凍・空調装置は、請求項１または請求項２の冷凍・空調装置において、負荷側熱交換器をバイパスするバイパス回路と、前記バイパス回路の冷媒流量を制御する流量制御手段を設けたものである。
【００１３】
本発明の請求項４に関わる冷凍、空調装置は、請求項３の冷凍・空調装置において、流量制御手段に、ロ−タリ−バルブを使用するものである。
【００１４】
また、枝管を、１本ずつ液もしくは気液二相冷媒を順次流して洗浄する場合、当該洗浄される枝管以外の枝管には小量の冷媒を流すものである。
【００１５】
また、この発明に係る冷凍・空調装置は、圧縮機、熱源側熱交換器等により構成される室外機ユニットと、複数の負荷側熱交換器等により構成される室内機ユニットと、前記室内機ユニットもしくは前記室外機ユニットの少なくとも一方に設けた絞り装置と、前記室外機ユニットと前記室内機ユニットを接続する液管、ガス管と、を備え、前記液管及び前記ガス管、並びに前記室内機ユニットのうち少なくとも一方が第1の冷媒、冷凍機油で使用したものの再使用であるものであり、前記第１の冷媒、冷凍機油とは相違する第２の冷媒、冷凍機油を使用するに際して、制御手段により、前記第２の冷媒を液もしくは気液二相とし、該液もしくは気液二相の第２の冷媒で前記再使用部分を洗浄するとともに、前記負荷側熱交換器の接続配管である枝管は、これらの枝管をグル−プに分けて液もしくは気液二相冷媒で洗浄するものである。
【００１６】
また、洗浄する枝管の配管断面積の和がほぼ等しくなるようにグル−プ分けするものである。
【００１７】
また、負荷側熱交換器の容量の和がほぼ等しくなるようにグル−プ分けするものである。
【００１８】
また、流量制御手段の開度を各負荷側熱交換器の容量に応じた固定開度としたものである。
【００１９】
また、流量制御手段の開度を負荷側熱交換器の接続配管である枝管で生じる圧力損失以上の圧力損失がつく固定開度とすること、または、そのような固定絞りを設けるものである。
【００２０】
また、流量制御手段の上流及び下流の圧力と流量制御手段の開度とから冷媒流量を算出し、流量制御手段の開度を補正するものである。
【００２１】
また、液管およびガス管の洗浄途中において、冷媒の流れの向きを反転させるものである。
【００２２】
また、洗浄途中において、洗浄する冷媒に相溶な油を流すものである。
【００２３】
また、洗浄途中において、洗浄する冷媒に非相溶もしくはわずかに相溶で、残留する油よりも粘度が低い油を流すものである。
【００２４】
また、洗浄途中において、洗浄する冷媒に相溶もしくは非相溶な油を流す時には、該油を冷媒ガスと共に循環させた後に、液もしくは気液二相冷媒を流すものである。
【００２８】
【発明の実施の形態】
実施の形態１．
本発明の実施の形態１を示す冷媒回路図を図１に示す。図１において、１は圧縮機、３は四方弁、１４は熱源側熱交換器、１５はアキュムレ−タ、１０６は開閉弁３４を有しホットガスを導入するバイパス回路でありこれらによって室外機ユニット５０を構成する。また、１６ａ、１６ｂは絞り装置、１７ａ、１７ｂは負荷側熱交換器（室内熱交換器）であり、これらによって室内機ユニット５１ａ、５１ｂを構成する。なお、室内機ユニットはａ、ｂの２系統を持つマルチ式空調機を示している。室外機ユニット５０と室内機ユニット５１は既設の液管１０１（Ａ〜Ｂ）および既設のガス管１０２（Ｃ〜Ｄ）で接続される。この際、既設の液管１０１の配管端部Ａ、Ｂは、それぞれ、室外ユニット５０の熱源側熱交換器１４側の配管端部、室内機ユニット５１の絞り装置１６側の配管端部と接続し、既設のガス管１０２の配管端部Ｃ、Ｄは、それぞれ、室外ユニット５０の四方弁３側の配管端部、室内機ユニット５１の負荷側熱交換器１７側の配管端部と接続する。これらで冷凍サイクルの冷媒回路を構成する。但し、室内機ユニット５１は、既設のものを使用してもよく、室内機ユニット５１は２系統に限らず、３系統以上でも、さらに１系統でもよい。４０、４１は、それぞれ圧縮機１の吐出圧力、吸入圧力を検知する圧力センサ、４２は吐出温度を検知する温度センサ、１１０は圧縮機の容量および熱源側熱交換器の容量等を決定、制御する制御器である。
【００２９】
この冷凍サイクルでは、例えば、R４０７Cのようなハイドロフルオロカーボン（ＨＦＣ）系冷媒
を使用する。また、既設配管１０１、１０２には、Ｒ２２のようなハイドロクロロフルオロカーボン（ＨＣＦＣ）系冷媒や、Ｒ５０２のようなクロロフルオロカーボン（ＣＦＣ）系冷媒を使った冷凍サイクルの潤滑油として用いられる鉱油がハイドロフルオロカーボン（ＨＦＣ）系冷媒に対する残留異物として既設配管１０１、１０２内に存在する（既設の室内機ユニット５１使用時は室内機ユニット５１にも存在する）。残留した鉱油が、ＨＦＣ系冷媒の冷凍機油として用いられるエステル油のような合成油と混合すると、冷凍機油の冷媒への溶解度が変化し、二相分離温度が上昇することから、圧縮機１の潤滑性が悪化したり、アキュムレータ１５から圧縮機１への返油ができず問題になる。このため、このような問題がない鉱油の残留量を予め試験的に決定しておき、その鉱油の残留量を洗浄の目標とする。
【００３０】
既設配管である液管１０１とガス管１０２を洗浄する場合には、前記冷媒回路へ必要量の、例えばＲ４０７Ｃのような冷媒を封入し、四方弁３を実線の向きに切替え、圧縮機１を起動する。圧縮機１を吐出したガス冷媒は、熱源側熱交換器１４で熱交換し、高圧の液もしくは二相冷媒となって液管１０１を流れる。液管１０１を流れた冷媒は、絞り装置１６ａ，１６ｂによって低圧の二相状態となって負荷側熱交換器１７ａ，１７ｂおよびガス管１０２を流れ四方弁３を介してアキュムレータに流れ込む。
【００３１】
このように冷媒が流れた際に、液もしくは二相状態の冷媒はせん断力によって、配管内壁面に付着した鉱油を壁面より分離し、その分離した鉱油を冷媒液中もしくは気液の界面を浮遊させながら輸送する。図２に、配管内をガスの状態で洗浄した場合と、気液二相状態で洗浄した場合の残油量を比較する。図２から、気液二相状態で洗浄した場合の方が、残油量が少なく、洗浄に適していることがわかる。一定時間、既設配管を洗浄した後、既設配管から回収された鉱油は、アキュムレータ１５の底部に滞留するので、開閉弁３５を開いて回収する。なお、アキュムレータ１５に液冷媒がある場合には、鉱油が液冷媒の気液界面に浮くため、開閉弁３４によりバイパス回路１０６を開きホットガスをアキュムレータ１５に導くこと、熱源側熱交換器１４を最大容量とすること、絞り装置１６ａ，１６ｂをより絞って運転すること、を適宜選択してアキュムレータ１５の液冷媒を予め蒸発させてから鉱油を回収することが望ましい。
【００３２】
従って、冷凍サイクル内に充填した冷媒によって配管内を洗浄した後、そのまま冷凍・空調運転を行うことができるので、工事を簡略化することができるとともに、スム−ズに冷凍・空調運転に移ることができる。
【００３３】
次に、洗浄運転時の制御器１１０の制御について図３の制御ブロック図で説明する。
図１の冷媒回路において、洗浄用の冷媒を液または二相状態とするために、図３に示すように、制御器１１０は、圧力センサ４０、４１及び温度センサ４２の検出値により、圧縮機１の運転周波数、絞り装置１６の開度、熱源側熱交換器１４の容量（熱交換器自体の容量及びファン回転数等）、開閉弁３４の開度および負荷側熱交換器の容量（熱交換器自体の容量及びファン回転数等）を決定、制御する。
一般的な制御として圧力センサ４０、４１により、圧縮機１の運転周波数、絞り装置１６の開度、熱源側熱交換器１４の容量（熱交換器自体の容量及びファン回転数等）の設定、制御の例を説明する。
図４はこの制御のフロ−チャ−トである。図４において、ステップ１（以下Ｓ１と記載する）で熱源側熱交換器１４の容量ＡＫ１４を予め設定した容量に設定する。このＡＫ１４の設定容量は外気温度、冷媒配管長等の条件によって適宜変更してもよい。Ｓ２で圧力センサ４０、４１から圧縮機１の吐出圧力Ｐｄ、圧縮機の吸入圧力Ｐｓを検知する。Ｓ３で予め設定しておいた目標吐出圧力Ｐｄｍと吐出圧力Ｐｄの差ΔＰｄ、目標吸入圧力Ｐｓｍと吸入圧力Ｐｓの差ΔＰｓを算出する。これらの算出値により、Ｓ４で圧縮機の運転周波数の補正値ΔＦｃｏｍｐと絞り装置１６の補正値ΔＡ１６を算出し、それぞれ算出値により制御して、Ｓ１に戻る。
なお、図４のａ、ｂ、ｃ、ｄは定数である。
【００３４】
また、圧縮機の吐出温度の過昇温及び液バック防止のために、図５のフロ−チャ−トに示すように、下記の制御をする。Ｓ１１では、温度センサ４２により圧縮機吐出温度Ｔｄ、圧力センサ４２から圧縮機吐出圧力Ｐｄを検知する。Ｓ１２では、予め設定しておく吐出温度の上限値Ｔｄｍａｘと吐出温度の検出値Ｔｄとを比較し、Ｔｄ＜Ｔｄｍａｘの場合はＳ１３へ移り熱源側熱交換器１４の容量の変更を行わない。Ｔｄ＞Ｔｄｍａｘの場合は、Ｓ１４へ移りＴｄｍａｘとＴｄの差に応じて、熱源側熱交換器１４の容量の補正値ΔＡＫ１４を算出し、制御する。Ｓ１５ではＴｄ−Ｔｓａｔ（吐出過熱度であり、飽和温度Ｔｓａｔは圧縮機吐出圧力Ｐｄから推定する）と予め設定しておく吐出過熱度の最小値ΔＴＳＨを比較し、Ｔｄ−Ｔｓａｔ＞ΔＴＳＨの場合はＳ１６へ進み熱源側熱交換器１４の容量の変更は行わない。Ｔｄ−Ｔｓａｔ＜ΔＴＳＨの場合は、圧縮機への液バックが大きいとしてＳ１７へ進み、熱源側熱交換器１４の容量ＡＫ１４と予め設定しておく最小値ＡＫｍｉｎとを比較し、ＡＫ１４＞ＡＫｍｉｎの場合は、Ｓ１８へ移り、熱源側熱交換器１４の容量の補正値ΔＡＫ１４を求め、制御する。ＡＫ１４＜ＡＫｍｉｎの場合は、Ｓ１９へ移り、開閉弁３４の開度の補正値ΔＡ３４を求め、制御する。
なお、図５のｅ、ｆ、ｇは定数である。
【００３５】
前記は、既設の液管１０１、既設のガス管１０２の洗浄とともに既設の室内機ユニット５１も洗浄可能とした場合（室内機ユニット５１のみが既設の場合は室内機ユニット５１を洗浄）であったが、室内機ユニット５１を新規に設置する場合には、図６のように室内機ユニット５１をバイパスする室内機バイパス回路１０７を設置し、洗浄時、開閉弁３０、３１を閉じ、流量制御手段である流量制御弁３２を開き、絞り装置１６ａ，１６ｂおよび室内熱交換器１７ａ，１７ｂをバイパスして液管１０１およびガス管１０２を洗浄後、開閉弁３０、３１を開き、流量制御弁３２を閉じれば、室内機ユニット５１を新設し、既設の液管１０１およびガス管１０２のみを洗浄することも可能である。洗浄運転時における洗浄用の冷媒を液または二相状態とするための制御器１１０の制御については、図６の冷媒回路において、制御器１１０は、圧力センサ４０、４１及び温度センサ４２の検出値により、圧縮機１の運転周波数、熱源側熱交換器１４の容量（熱交換器自体の容量及びファン回転数等）および開閉弁３４の開度を決定、制御する。
【００３６】
また、本実施の形態では、冷凍サイクル内に充填する冷媒としてＨＦＣ系冷媒を用いる例を示したが、そのまま冷凍・空調運転を行う冷媒で、環境に配慮した冷媒であればＨＦＣ系冷媒に限らなくてもよく、例えば、プロパン系やイソブタン系のハイドロカーボン（ＨＣ）系冷媒でもよい。
また、絞り装置１６を室内機ユニット５１側に設けたが、室外機ユニット５０側で、熱源側熱交換器１４の下流に設けてもよい。
【００３７】
実施の形態２．
図７は、本発明の実施の形態２を示す冷媒回路図である。図中、実施の形態１と同一部分には、同一の記号を付し、説明を省略する。図７において、１９は油分離器、２０は異物回収器、２１は減圧装置、２２は冷媒熱交換器、２３は油戻し回路、２４、２５，２６，２７，２８，２９は開閉弁であり、これらを配管接続して、洗浄回路である洗浄ユニット５２を構成する。洗浄ユニット５２は、既設の液管１０１の配管端部Ａ、既設のガス管１０２の配管端部Ｃ及び室外ユニット５０の両配管端部間に配管接続される。
【００３８】
既設配管である液管１０１とガス管１０２を洗浄する場合には、前記冷媒回路へ必要量の冷媒を封入し、四方弁３を実線の向きに切替え、開閉弁２６、２９を閉とし、圧縮機１を起動する。圧縮機１を吐出したガス冷媒は、熱源側熱交換器１４で熱交換し、ここで適度の熱量を放熱し、開閉弁２４を経て、洗浄ユニット５２に入り、油分離器１９に至る。油分離器１９では、新しくユニット内に充填された冷凍機油を分離し、分離した冷凍機油を油戻し回路２３、開閉弁２７を経て、室外ユニット５０へ戻す。油分離器１９で油を分離したガス冷媒は、冷媒熱交換器２２で凝縮して液もしくは気液二相状態の冷媒となって、開閉弁２５を経て既設の液管１０１を流れる。液管１０１を流れた冷媒は、絞り装置１６ａ、１６ｂによって低圧の二相状態となって負荷側熱交換器１７ａ、１７ｂおよび既設のガス管１０２を流れると共に、液もしくは二相状態の冷媒のせん断力によって、配管内壁面に付着した鉱油を壁面より分離し、その分離した鉱油を冷媒液中もしくは気液の界面を浮遊させながら輸送する。既設のガス管１０２を流れた気液二相冷媒は、開閉弁２８を経て洗浄ユニット５２に入り、減圧装置２１で若干絞られた後、冷媒熱交換器２２で油分離器１９から流出した高温の冷媒と熱交換し、自身は蒸発気化して異物回収器２０へ流れる。異物回収器２０では、既設配管である液管１０１およびガス管１０２から回収した鉱油を分離し、開閉弁２７を経て冷媒のみを室外ユニット５０へ戻す。
【００３９】
よって、既存の配管内に残留している劣化した冷凍機油を回収し、洗浄後、回収した冷凍機油が再び冷媒回路内に散乱することを防止することができる。また、洗浄運転中に必要な液もしくは気液二相状態の冷媒を冷媒熱交換器２２を使用することで得ることができるので、熱源側熱交換器１４、負荷側熱交換器１７のファンの駆動動力やファンの制御が不必要であり、経済的であり、制御も簡易である。
【００４０】
また、図８には、液管１０１からガス管１０２の向きに冷媒を流した場合の冷媒の流れ方向の乾き度の変化を、図９には、液管１０１からガス管１０２の向きに冷媒を流した場合の冷媒の流れ方向の配管内の圧力の分布を示す。図８から、液管１０１での冷媒の乾き度の変化が大きく、ガス管１０２での乾き度の変化は小さいことがわかる。さらに、図９から、圧力の変化は液管１０１で大きいことがわかる。一般に同一流量において配管での圧力損失は乾き度が小さいほど小さくなるので、配管が細くガス管１０２よりも流路抵抗が大きくなる液管１０１で、冷媒の乾き度を小さくするれば、圧力損失は小さくなる。冷凍サイクル内に充填した冷媒充填量が一定の場合、液管１０１側からガス管１０２側に流す場合の配管中の平均の乾き度はガス管１０２側から液管１０１側へ冷媒を流した場合の配管中の平均の乾き度よりも小さく、液管１０１からガス管１０２の向きに冷媒を流すことによって、ガス管１０２から液管１０１の向きに冷媒を流した場合よりも圧力損失を小さくすることができる。従って、液管１０１からガス管１０２へ洗浄することにより、配管全体の圧力損失を支配する液管１０１での冷媒の乾き度を小さくすることで圧力損失を低減でき、冷媒流量をより大きくし洗浄時間を短縮することができる。
【００４１】
前記は、既設の液管１０１、既設のガス管１０２の洗浄とともに既設の室内機ユニット５１も洗浄可能とした場合（室内機ユニット５１のみが既設の場合は室内機ユニット５１を洗浄する）であったが、室内機ユニット５１を新規に設置する場合には、図１０に示すように、負荷側熱交換器１７および絞り装置１６をバイパスする室内機バイパス回路１０８を設け、このバイパス回路１０８上に流量制御手段である流量制御弁３２を設けると共に、既設の液管１０１と絞り１６の間に開閉弁３０と、既設のガス管１０２と負荷側熱交換器１７の間に開閉弁３１を設けることにより、室内機ユニット５１を新設し、既設の液管１０１およびガス管１０２のみを洗浄することも可能である。
【００４２】
また、負荷側熱交換器１７および絞り装置１６をバイパスする室内機バイパス回路１０８と、このバイパス配管１０８上に設けた流量制御弁３２と、液管１０１と絞り１６の間の開閉弁３０と、ガス管１０２と負荷側熱交換器１７の間の開閉弁３１とにより構成されるバイパスユニット５３において、流量制御弁３２および開閉弁３０、３１の変わりに、図１１に示すロータリーバルブを使用すると、洗浄の信頼性を高めることができる。つまり、ロータリーバルブを、駆動モータ４３、ギヤ４４、第一弁４５、第二弁４６等で構成し、第一弁４５のリフト量で挟部４７の開度調節し、配管１０３ｂと１０３ｄの間の流路抵抗を変更する。この時、配管１０３ｂおよび１０３ｄは、配管１０３ａ、１０３ｃをは完全に分離された状態となっている。また、第一弁４５の下面と第二弁４６の上面とが接した場合、第一弁４５と第二弁４６は一体となって回転し、配管１０３ｂと１０３ｄを閉塞し、配管１０３ａと１０３ｂが孔４８を介して流路を形成すると共に、配管１０３ｃと１０３ｄが孔４９を介して流路を形成する。このロータリーバルブの配管１０３ａを負荷側熱交換器のガス管側と接続し、配管１０３ｃを絞り装置１６と接続する。また、室内機バイパス回路１０８の一端を配管１０３ｂ、他端を１０３ｄと接続する。
【００４３】
洗浄の際には、配管１０３ｂと配管１０３ｄを前記挟部４７を介して接続し、挟部４７の開度を調節しながら液管１０１およびガス管１０２を洗浄する。また、洗浄終了後は、前記第一弁４４をリフトし、第一弁４５と第二弁４６を回転し、配管１０３ａと配管１０３ｂとを流通させると共に、配管１０３ｃと配管１０３ｄとを流通させることによって、通常の冷凍・空調運転を行う。このことによって、バイパスユニット５３を安価に製造できると共に、開閉弁３０、３１を閉じて洗浄する際の、メイン冷媒配管（既設の液管１０１、既設のガス管１０２に接続している主管）の枝管における室内機バイパス回路１０８への分岐部（Ｅａ、Ｅｂ、Ｆａ、Ｆｂ）から開閉弁３０、３１までの盲腸配管部への異物の溜まり込みを防止し、洗浄の信頼性を高めることができる。
このロ−タリバルブは、実施の形態１の図６の冷媒回路にも利用できる。
【００４４】
また、洗浄ユニット５２は、既設配管１０１、１０２、室内機ユニット５１を洗浄後は、開閉弁２４，２５，２７，２８を閉じ、開閉弁２４，２５，２７，２８を該冷凍・空調装置の一部として残した状態で取外し（開閉弁２６，２９は開として残す）、他の冷凍・空調装置の既設配管洗浄時に使用してもよい。
また、本実施の形態でも、絞り装置１６を室内機ユニット５１側に設けたが、室外機ユニット５０側で、熱源側熱交換器１４の下流に設けてもよい。
なお、本実施の形態においても、制御器により洗浄冷媒を液もしくは気液二相冷媒に制御する。
【００４５】
実施の形態３．
実施の形態３は、複数の室内機ユニット５１の洗浄に関するもので、その他の点は実施の形態１、２と同様である。図１２は、図１、図１０に示すような冷媒回路構成において、負荷側熱交換器１７の接続台数の変化に対する負荷側熱交換器１７の接続配管（既設の液管１０１と既設のガス管１０２にそれぞれ接続されている主管間の接続配管で、負荷側熱交換器１７が接続されている枝管）トータルの流路断面積および単位断面積当りの冷媒流量の変化を示す。図１２から、負荷側熱交換器１７の接続台数の増加に合せて負荷側熱交換器１７と接続する配管トータルの流路断面積が増大し、この結果、これら複数の配管１本ずつに流れる冷媒流量が減少するので、配管１本ずつを洗浄することにより、洗浄に必要な冷媒流量を確保することが可能である。
【００４６】
また、図１３には、主管１１１と各室内機ユニット５１を接続する枝管１１２との接続部付近の洗浄中の冷媒の流れの様子を示す。ここで主管１１１とは、例えばガス管１０２に接続している配管で、複数の負荷側熱交換器１７が分岐している配管であり、枝管１１２とは、負荷側熱交換器１７を主管１１１に接続する配管である。図１３のように、気液二相冷媒が枝管１１２を上昇し主管１１１へ流入する場合には、枝管１１２内の流動様式は、気泡流もしくは環状流のような流動様式となる。このため、開閉弁３０、３１を閉じて枝管１１２の流れを止めると、図１４に示すように、冷媒ガスが浮力によって上昇し、冷媒液は主管１１１から枝管１１２へ流れ込むようになる。この時、開閉弁３０、３１を閉じる配管には、開閉弁３０、３１を完全に閉じずに、少し開けて多少の冷媒流量を流すことによって、洗浄配管への異物の逆流を防止することができる。また、開閉弁３０、３１を閉じる配管への冷媒の寝込みによる冷媒不足も解消できる。
【００４７】
さらに、複数の配管を１本ずつ洗浄する場合には、１本ずつ所定の時間洗浄してもよいが、始めに洗浄した枝管と最後に洗浄した枝管を比較すると、始めに洗浄した枝管の方が枝管上流の残油量が多く、冷媒中を流れる鉱油が洗浄中の枝管に再付着する可能性が大きくなるので、まず、所定の洗浄時間のうち、例えば、１／３の時間洗浄し、次の配管を洗浄して再度初めの配管を洗浄する等、配管１本ずつを数回に分けて洗浄してもよく、このようにすることで各枝管について、洗浄のばらつきを低減することができる。
【００４８】
実施の形態４．
図１５は、図1、図１０に示す冷媒回路において、負荷側熱交換器１７の接続台数の変化に対する負荷側熱交換器１７の接続配管（枝管）トータルの流路断面積および単位断面積当りの冷媒流量の変化を示す。ここで、負荷側熱交換器１７と接続される枝管の管径は全て等しいとすると、配管を洗浄する場合、１本ずつ洗浄するよりも、洗浄に必要な冷媒流量が確保できる配管をグルーピングして、各グループ毎に洗浄する方が洗浄時間を短縮できる。つまり、予め試験室で試験をして洗浄に必要な冷媒流量を設定し、即ち、単位断面積当りの必要な冷媒流量を設定し、図１５から、洗浄に必要な流量が得られるような台数ｎを設定し、ｎ台を１グル−プとして洗浄することによって、即ち、洗浄に必要な冷媒流量が得られる配管断面積で、かつ、グル−ピングされる配管の断面積の和が等しくなるように枝管をグル−プ分けして（1本で１グル−プの場合もある）洗浄することによって、１度で複数の枝管を洗浄することができるので、洗浄時間を短縮できる。
さらに、負荷側熱交換器１７の容量と該負荷側熱交換器１７と接続される配管径とは図１６に示すような１対１の関係があるため、洗浄に必要な冷媒流量が得られる配管断面積で、かつ、グル−ピングされる負荷側熱交換器１７の容量の和が等しくなるように枝管をグル−プ分けしても同様の効果を奏する。
但し、グル−ピングされる配管の断面積の和、負荷側熱交換器１７の容量の和が等しくなくても、洗浄に必要な冷媒流量が確保されるようにグル−ピングしてもよい。
【００４９】
また、洗浄に必要な冷媒流量は、配管の長さ・配管径のアンバランス、洗浄時間、冷媒流量、油の種類、鉱油の粘度等によって変化するので、グループ分けの際には、予め、最適なグループ台数を選定しておくことが望ましい。
【００５０】
また、図１６は、各負荷側熱交換器１７の容量と、その負荷側熱交換器１７に接続される液管またはガス管の枝管の管径の対比を示す。図１６に示すように、一定の範囲内毎に、接続される配管径が決まっている。そこで、図16に示すように、負荷側熱交換器１７の容量と配管径との間には1対１の関係が成立ち、かつ、図１７に示すように、負荷側熱交換器１７の容量と洗浄に必要な冷媒流量にも１対１の関係が成立つので、流量制御弁３２の開度を負荷側熱交換器１７の容量によって決まる固定開度とすると、配管径に応じた冷媒流量分配を行うことができるので、各配管ごとに洗浄に必要な冷媒分配が可能となる。つまり、流量制御弁３２の開度を予め負荷側熱交換器１７の容量に応じた固定開度とすることで、配管の施工状態を調べることなく、洗浄に必要な冷媒流量が得られるように冷媒分配量をコントロ−ルすることができる。従って、各グル−プ内での各枝管へ分配される冷媒流量のアンバランスを小さくし、洗浄の信頼性を容易に確保できる。
なお、枝管上に流量制御弁３２とは別の固定絞りを設けても同様の効果が得られる。
【００５１】
また、図１８は、配管長さが異なるものが同じグル−プにグル−ピングされた場合における、流量制御手段である流量制御弁３２での圧力損失の変化に対する該グル−プ内での平均冷媒流量と該グル−プでの最小流量の変化とを示している。図１８に示すように、流量制御弁３２での圧力損失が大きくなるとともに、最小流量は平均流量に漸近し、枝配管の圧力損失とほぼ同等の圧力損失ΔＰ（図に実線で示したΔＰ値）をつけた場合には、平均流量のおよそ３分の２以上とすることが可能である。従って、各グル−プ内での各枝管へ分配される冷媒流量のアンバランスを小さくし、洗浄の信頼性を容易に確保することができる。
なお、洗浄に必要な冷媒流量が得られる圧力損失を予め求めておけば、流量制御弁３２でつける圧力損失は枝管の圧力損失と同等以下でもかまわない。さらに、グル−ピングされる配管の配管径が異なる場合でも、枝配管の圧力損失とほぼ同等の圧力損失ΔＰをつけた場合には、各枝管へ分配される冷媒流量のアンバランスを小さくし、洗浄の信頼性を容易に確保することができる。
【００５２】
実施の形態５．
図１９は、発明の実施の形態５を示す冷媒回路図である。図中、１は圧縮機、３は四方弁、１４は源側熱交換器、１５はアキュムレータであり、これらによって室外機ユニット５０を構成する。１６は流量制御手段である絞り装置、１７は負荷側熱交換器であり、これらによって室内機ユニットを構成する。１０１は、前記室外機ユニット５０と前記室内機ユニットを接続する既設配管である液管、１０２は前記室外機ユニット５０と前記室内機ユニットを接続する既設配管であるガス管である。１９は油分離器、２０は異物回収器、２１は減圧装置、２２は冷媒熱交換器、２３は油戻し回路、２４、２５，２６，２７，２８，２９は開閉弁であり、これらによって、洗浄ユニット５２を構成する。さらに、３４、３５は、絞り装置１６の入口側、出口側の温度センサを示す。
【００５３】
既設配管である液管１０１とガス管１０２を洗浄する場合には、前記冷媒回路へ必要量の冷媒を封入し、四方弁３を実線の向きに切替え、開閉弁２６，２９を閉として、圧縮機１を起動する。圧縮機１を吐出したガス冷媒は、熱源側熱交換器１４で熱交換し、ここで適度の熱量を放熱し油分離器１９に至る。油分離器１９では、新しくユニット内に充填された冷凍機油を分離し、分離した冷凍機油を油戻し回路２３を介して室外機ユニット５０へ戻す。油分離器１９で油を分離したガス冷媒は、冷媒熱交換器２２で凝縮して液もしくは気液二相状態の冷媒となって、液管１０１を流れる。液管１０１を流れた冷媒は、絞り装置１６ａ，１６ｂによって低圧の二相状態となって負荷側熱交換器１７ａ，１７ｂおよびガス管１０２を流れると共に、液もしくは二相状態の冷媒のせん断力によって、配管内壁面に付着した鉱油を壁面より分離し、その分離した鉱油を冷媒液中もしくは気液の界面を浮遊させながら輸送する。ガス管１０２を流れた気液二相冷媒は、減圧装置２１で若干絞られた後、冷媒熱交換器２２で油分離器１９から流出した高温の冷媒と熱交換し、自身は蒸発気化して異物回収器２０へ流れる。異物回収器２０では、既設配管である液管１０１およびガス管１０２から回収した鉱油を分離し、冷媒のみを室外機ユニット５０へ戻す。
【００５４】
図２０は絞り装置１６ａおよび１６ｂの開度の設定方法を示すフローチャートである。図２０に従って、絞り装置１６ａおよび１６ｂの開度の設定方法を説明する。以下の記載において、添え字のｉは、複数の室内ユニットのｉ番目を示し、Pi1、Pi2は絞り装置１６の入口側、出口側の圧力であり、温度センサ３４，３５の検出値から飽和圧力として推定する。Aiは絞り装置１６の開度であり、Ci、ｋｉは係数（定数）である。
図２０において、ステップ１（以下Ｓ１、Ｓ２…と記す）では、温度センサ３４、３５の検知値から圧力Pi1、Pi2を推定する。Ｓ２では、差圧ΔPi＝ Pi1‐Pi2を算出する。Ｓ３では、各室内熱交換器を流れる配管の単位断面当りの冷媒流量G i = Ci・Ai・√ΔPiを算出する。Ｓ４では、各室内機を流れる配管の単位断面積当りの冷媒流量の平均値を算出する。Ｓ５では、各室内機を流れる配管の単位断面積当りの冷媒流量の平均値Gmと先に算出した冷媒流量G iとの差ΔG iを算出する。Ｓ６では、絞り装置１６の開度の変更値Ai’を算出、制御する。 Ｓ７では、洗浄運転終了時間を判断し、洗浄終了時間に達した場合は絞り装置１６の制御を終了する。洗浄終了時間に達しない場合には、絞り装置１６の開度を設定し、Ｓ１に戻る。
【００５５】
以上のように、絞り装置１６の開度を設定することにより、配管長や配管径の違いによる枝管への冷媒分配の不均一を低減し、配管長、配管径・高低差等による各グループ内での配管への冷媒分配量のアンバランスを高精度に補正し、洗浄の信頼性を高めることができる。
図19の冷媒回路図は、負荷側熱交換器１７に室内機バイパス配管のない例であるが、図10のようにバイパス配管１０８を有する場合は、流量制御手段としての流量制御弁３２を、その前後の圧力で前記の絞り装置１６と同様に制御する。
【００５６】
実施の形態６．
図２１は、本発明の実施の形態６を示す冷媒回路図である。図中、実施の形態１と同一部分には、同一の記号を付し、説明を省略する。図２１において、１９は油分離器、２０は異物回収器、２１は減圧装置、２２は冷媒熱交換器、２３は油戻し回路、２４、２５，２６，２７，２８，２９は開閉弁であり、これらによって洗浄ユニット５２を構成する。
【００５７】
既設配管である液管１０１とガス管１０２を洗浄する場合には、前記冷媒回路へ必要量の冷媒を封入し、四方弁３を破線の向きに切替え、開閉弁２６，２９を閉とし、圧縮機１を起動する。圧縮機１を吐出したガス冷媒は、四方弁を介し、開閉弁２７を経て油分離器１９に至る。油分離器１９では、新しくユニット内に充填された冷凍機油を分離し、分離した冷凍機油を油戻し回路２３および開閉弁２４を介して室外ユニット５０へ戻す。油分離器１９で油を分離したガス冷媒は、冷媒熱交換器２２で凝縮して液もしくは気液二相状態の冷媒となって、開閉弁２８を経てガス管１０２を流れる。ガス管１０２を流れた冷媒は、負荷側熱交換器１７ａ、１７ｂと絞り装置１６ａ、１６ｂをバイパスし、バイパスユニット５３ａ、５３ｂを流れ、流量制御弁３２ａ、３２ｂによって若干絞られた後、液管１０１を流れるとともに、液もしくは二相状態の冷媒のせん断力によって、配管内壁面に付着した鉱油を壁面より分離し、その分離した鉱油を冷媒液中もしくは気液の界面を浮遊させながら輸送する。液管１０１を流れた気液二相冷媒は、開閉弁２５を経て洗浄ユニット５２に入り、減圧装置２１で若干絞られた後、冷媒熱交換器２２で油分離器１９から流出した高温の冷媒と熱交換し、自身は蒸発気化して異物回収器２０へ流れる。異物回収器２０では、既設配管である液管１０１およびガス管１０２から回収した鉱油を分離し、冷媒のみを開閉弁２４を経て室外ユニット５０へ戻す。
【００５８】
図２２に冷媒の流れ方向に対する冷媒の圧力の変化を示す。図２２から、圧力はガス管１０２部でほぼ一定値であり、圧力は液管１０１部で大きく低下することがわかる。この結果、冷媒の流れ方向の温度分布は、図２３に示すようにガス管１０２部で一様に高圧の飽和温度になることがわかる。
【００５９】
この結果、ガス管１０２には高温・高圧の気液二相冷媒が流れるので、ガス管１０２中に残留する鉱油の粘度を低減させ、冷媒のせん断力によってスムーズに移動させることができので、洗浄時間を低減することができる。
【００６０】
なお、ヘッダ等による分岐管を使った枝管の分岐では、図２４および図２５に示すような袋小路の配管が存在する場合がある。このとき、冷媒を流す向きが、図２４のように袋小路の先端に向かって垂直に流れる場合は、洗浄冷媒が袋小路の先端まで十分に行届かず洗浄が不充分になる。そこで、図２５に示すように袋小路の先端に向かって平行に冷媒を流入させ、液冷媒の慣性力によって袋小路先端部まで液冷媒を飛ばすことで、袋小路の洗浄を行うことが望ましい。ところが、既設の冷媒配管の場合には、配管の施工状態が予めわからないことがあるので、図２６（図２７）に示すように、四方弁３５を配置し（図２１の冷媒回路図に四方弁３５を配管接続する）、冷媒の流れ方向を、洗浄途中で図２６から図２７、または図２７から図２６のように反転させると、冷媒配管中に袋小路状の分岐管部を持つような冷媒配管を洗浄する場合でも、十分に洗浄することができるので、洗浄の信頼性が高まる。
また、熱源側熱交換器１４は、既設配管での吸熱または放熱の加減から、高圧側、もしくは、低圧側のどちらかに選択して使用することが望ましい。
【００６１】
実施の形態７．
図２８は、本発明の実施の形態７を示す冷媒回路図である。図中、実施の形態１と同一部分には、同一の記号を付し、説明を省略する。図２８において、３６、３７、３８は開閉弁、３９は油タンクであり、配管等を用いてもよい。油タンク３９内部には、冷媒液に相溶な油を封入する。ここで油タンク３９に封入する油は、室外ユニット５０に内蔵された圧縮機１の冷凍機油と同じでも、異なってもかまわない。
【００６２】
既設配管である液管１０１とガス管１０２を洗浄する場合には、前記冷媒回路へ必要量の冷媒を封入し、四方弁３を実線の向きに切替え、開閉弁２６、２９、３７、３８を閉とし、開閉弁３６を開とし、圧縮機１を起動する。圧縮機１を吐出したガス冷媒は、熱源側熱交換器１４で熱交換し、ここで適度の熱量を放熱し油分離器１９に至る。油分離器１９では、新しく室外ユニット５０内に充填された冷凍機油を分離し、分離した冷凍機油を室外ユニット５０へ戻す。油分離器１９で油を分離したガス冷媒は、冷媒熱交換器２２で凝縮して液もしくは気液二相状態の冷媒となって、液管１０１を流れる。液管１０１を流れた冷媒は、絞り装置１６ａ，１６ｂと負荷側熱交換器１７ａ、１７ｂをバイパスし、バイパスユニット５３ａ、５３ｂを流れ、流量制御弁３２ａ、３２ｂによって若干絞られた後、ガス管１０２を流れるとともに、液もしくは二相状態の冷媒のせん断力によって、配管内壁面に付着した鉱油を壁面より分離し、その分離した鉱油を冷媒液中もしくは気液の界面を浮遊させながら輸送する。ガス管１０２を流れた気液二相冷媒は、減圧装置２１で若干絞られた後、冷媒熱交換器２２で油分離器１９から流出した高温の冷媒と熱交換し、自身は蒸発気化して異物回収器２０へ流れる。異物回収器２０では、既設配管である液管１０１およびガス管１０２から回収した鉱油を分離し、冷媒のみを室外ユニット３０へ戻す。
【００６３】
洗浄において、ある一定時間後において、配管内に残留する鉱油の量が一定値以下になったと推定される時間において、開閉弁３６を閉じ、開閉弁３７，３８を開放することによって、油タンク３９内部の油を既設配管である液管１０１およびガス管１０２へ導く。この結果、油タンク３９から流出した油と液管１０１およびガス管１０２内部に残留する油とが混合し、冷媒液への溶解度が増加し、配管内面に液膜状に残留する鉱油が液冷媒に相溶な油とともに液冷媒に溶解するので、鉱油の回収速度が増大する。図２９はこの効果を示した図であり、横軸に洗浄時間、縦軸に配管内に残留する鉱油の量をとっている。図中、ラインＡは、油タンク３９から液冷媒に相溶な油を流さない場合の残油量であり、ラインＢは、洗浄開始後、適当な時間後に油タンク３９から液冷媒に相溶な油を流した場合の残油量を示している。図２９からわかるように、油タンク３９から液冷媒に相溶な油を流した場合には、油タンク３９から液冷媒に相溶な油を流さない場合に比べて、配管内に残留する鉱油の量が同一量となるまでの洗浄時間が半分以下になることがわかる。したがって、適当な時間に油タンク３９から液冷媒に相溶な油を流すことで、目標の残油量まで洗浄する時間を短縮する効果がある。ここで、適当な時間とは、例えば、洗浄によって配管内壁面に付着した油が液滴状もしくは膜状となるまでの時間のことである。
【００６４】
ここで、油タンク３９内に予め充填しておく油の量は、洗浄中に油タンク３９から油を投入する時の液管およびガス管に残留する油の量を考えて、油タンク３９内の油と液管およびガス管に残留する油とが混合した際に、この混合油が冷媒液にある程度の溶解性が確保できる量とする。
【００６５】
また、液管１０１およびガス管１０２の長さが長い場合において、油タンク３９に封入する油を冷媒液に相溶な油とすると、液管およびガス管中の鉱油と該相溶な油とが直接接触する前に、該相溶な油に液冷媒が溶解し、該相溶な油が希釈されるので、配管中に残留する鉱油を溶解する効果が小さくなることがある。この場合には、油タンク３９に封入する油を冷媒液に非相溶な油とし、その油の粘度を配管中に残留する鉱油の粘度よりも小さくすることで、該非相溶な油を液もしくは気液二相冷媒とともに流しても該非相溶な油に冷媒が溶けることがなく、液管およびガス管内の鉱油と該非相溶な油とを直接接触させて混合油とすることが可能となり、さらに、この混合油は、もともと配管中に残留していた鉱油の粘度よりも小さく流動性に富むので、液管およびガス管中の鉱油をすばやく回収することができ、洗浄時間を短縮することができる。
【００６６】
さらに、油タンク３９に封入する油を液管１０１およびガス管１０２へ導入する際には、冷媒熱交換器２２をバイパスし、ガス冷媒と共に油タンク３９に封入する油を液管１０１およびガス管１０２へ導くことで、油タンク３９内の油は液管１０１およびガス管１０２の内壁面を薄い膜状になって流れ、液管１０１およびガス管１０２内に存在する鉱油と一様に接触させることが可能となるので、液管１０１およびガス管１０２内の鉱油と油タンク３９に封入する油との混合油を気液二相冷媒を使って回収することで、油タンク内に相溶な油を充填した場合には液冷媒に溶解することで鉱油の洗浄速度を上げることができる。また、油タンク内に非相溶で液管１０１およびガス管１０２中に残留する鉱油の粘度より小さな油を充填した場合には鉱油と該非相溶油の混合油の粘度を下げ、流動性を向上させることで、洗浄速度を上げることが可能となり、洗浄の信頼性を高めることができる。
【００６７】
【発明の効果】
以上のように、この発明の冷凍・空調装置によれば、圧縮機、熱源側熱交換器等により構成される室外機ユニットと、複数の負荷側熱交換器等により構成される室内機ユニットと、前記室内機ユニットもしくは前記室外機ユニットの少なくとも一方に設けた絞り装置と、前記室外機ユニットと前記室内機ユニットを接続する液管、ガス管と、を備え、前記液管及び前記ガス管、並びに前記室内機ユニットのうち少なくとも一方が第1の冷媒、冷凍機油で使用したものの再使用であるものであり、前記第１の冷媒、冷凍機油とは相違する第２の冷媒、冷凍機油を使用するに際して、制御手段により、前記第２の冷媒を液もしくは気液二相とし、該液もしくは気液二相の第２の冷媒で前記再使用部分を洗浄するとともに、前記複数の負荷側熱交換器の接続配管である枝管は、１本ずつ、液もしくは気液二相冷媒を順次流して洗浄するものである。これにより、劣化した第１の冷凍機油を速やかに洗浄・回収し、洗浄運転後には、そのまま、通常の冷凍・空調機として使用できるので、工事が簡単にできる。
また、負荷側熱交換器の接続配管である枝管を、１本ずつ、液もしくは気液二相冷媒を順次流して洗浄するので、枝管を洗浄する冷媒流量が不足することがない。また、室外機ユニットと室内機ユニットを接続する液管もしくはガス管の流路断面積よりも各負荷側熱交換器が接続する枝管の流路断面積の和が大きくなる場合でも、配管の洗浄に必要な冷媒流量を確保し洗浄の信頼性を高めることができる。
【００６８】
本発明の請求項２に関わる冷凍・空調装置は、請求項１の冷凍・空調装置において、異物回収器と冷媒熱交換器を有する洗浄回路を備えたので、既存の配管内に残留している劣化した冷凍機油を回収し、洗浄後、回収した冷凍機油が再び冷媒回路内に散乱することを防止することができる。また、洗浄運転中に必要な液冷媒を冷媒熱交換器を使用することで得ることができるので、ファンの駆動動力やファンの制御が不必要であり、経済的であり、制御も簡易である。
【００６９】
本発明の請求項３に関わる冷凍・空調装置は、請求項１または請求項２の冷凍・空調装置において、負荷側熱交換器をバイパスするバイパス回路と、前記バイパス回路の冷媒流量を制御する流量制御手段を設けたので、室内機を新規に交換したときは、バイパス回路を介して液管およびガス管の洗浄ができ、洗浄効率が向上する。
【００７０】
本発明の請求項４に関わる冷凍・空調装置は、請求項３の冷凍・空調装置において、流量制御手段に、ロ−タリ−バルブを使用するので、簡易な構成で流量を制御することができ、また、枝管にできる盲腸配管部をなくし、洗浄時に劣化した冷凍機油が盲腸配管部にに滞留することを防止することで、洗浄の信頼性を高めることができる。
【００７２】
本発明の請求項５に関わる冷凍・空調装置は、請求項１に記載の冷凍・空調装置において、負荷側熱交換器の接続配管である枝管に、１本ずつ液もしくは気液二相冷媒を順次流して洗浄する場合、他の負荷側熱交換器の枝管には、小量の冷媒を流すので、負荷側熱交換器へ連絡する液管およびガス管のうち、洗浄していない枝管へ冷媒が逆流し、洗浄した配管に劣化した冷凍機油が再付着することを防止することができる。
【００７３】
本発明の請求項６に関わる冷凍・空調装置は、請求項１乃至請求項４のいずれか１項に記載の冷凍・空調装置において、複数の負荷側熱交換器を備え、前記負荷側熱交換器の接続配管である枝管の洗浄は、前記枝管をグル−プに分けて液もしくは気液二相冷媒で洗浄するので、洗浄時間を短縮することができる。
【００７４】
本発明の請求項７に関わる冷凍・空調装置は、請求項６記載の冷凍・空調装置において、洗浄する枝管の配管断面積の和がほぼ等しくなるようにグル−プ分けするので、各グループ毎に配管へ一定の冷媒流量を流すことができるので、洗浄の信頼性を高めることができる。
【００７５】
本発明の請求項８に関わる冷凍・空調装置は、請求項６記載の冷凍・空調装置において、負荷側熱交換器の容量の和がほぼ等しくなるようにグル−プ分けするので、液管およびガス管が建物に埋設されたり、配管の施工図面がなく配管の断面積が直接わからない場合でも、各グループ毎に一定の冷媒流量を配管へ流すことができるので、洗浄の信頼性を高めることができる。
【００７６】
本発明の請求項９に関わる冷凍・空調装置は、請求項６乃至請求項８のいずれか１項に記載の冷凍・空調装置において、流量制御手段の開度を各負荷側熱交換器の容量に応じた固定開度としたので、グル−プ内での各枝管へ分配される冷媒流量のアンバランスを小さくし、洗浄の信頼性を高めることができる。
【００７７】
本発明の請求項１０に関わる冷凍・空調装置は、請求項６乃至請求項８のいずれか１項に記載の冷凍・空調装置において、流量制御手段の開度を負荷側熱交換器の接続配管である枝管で生じる圧力損失以上の圧力損失がつく固定開度とすること、または、そのような固定絞りを設けるので、グル−プ内での各枝管へ分配される冷媒流量のアンバランスを小さくし、洗浄の信頼性を高めることができる。
【００７８】
本発明の請求項１１に関わる冷凍・空調装置は、請求項６乃至請求項８のいずれか１項に記載の冷凍・空調装置において、流量制御手段の上流の圧力、下流の圧力と流量制御手段の開度とから冷媒流量を算出し、流量制御手段の開度を補正するので、各グループ内での流量のアンバランスを高精度に補正し配管長・高低差に対する制御範囲を広げ、洗浄の信頼性をさらに高めることができる。
【００８１】
本発明の請求項１２に関わる冷凍・空調装置は、請求項１乃至請求項９のいずれか１項の冷凍・空調装置において、液管およびガス管の洗浄途中において、冷媒の流れの向きを反転させるので、複数の負荷側熱交換器へ連絡する液管およびガス管への冷媒分配器等へ溜まりこむ油の滞留量を低減することができる。
【００８２】
本発明の請求項１３に関わる冷凍・空調装置は、請求項１乃至請求項１２の冷凍・空調装置において、洗浄途中において、洗浄する冷媒に相溶な油を流すので、既設の液管およびガス管中の劣化した油を該油と混合させ、その混合油を冷媒に溶かして回収することによって、洗浄時間を短縮することができる。
【００８３】
本発明の請求項１４に関わる冷凍・空調装置は、請求項１乃至請求項１２の冷凍・空調装置において、洗浄途中において、洗浄する冷媒に非相溶もしくはわずかに相溶で、粘度が残留する油よりも低い油を流すので、冷媒液により該油が希釈されることを防止し、該油を既設配管中の劣化した油と確実に混合し、粘度を低下させることで、前記混合油の移動速度を高め、洗浄時間を短縮することができる。
【００８４】
本発明の請求項１５に関わる冷凍・空調装置は、請求項１４記載の冷凍・空調装置において、洗浄途中において、洗浄する冷媒に相溶もしくは非相溶な油を流す時には、該油を冷媒ガスと共に循環させた後に、液もしくは気液二相冷媒を流すので、該油と既設配管中の冷凍機油の混合を確実にし、洗浄時間をさらに短縮することができる。
【図面の簡単な説明】
【図１】本発明の実施の形態１を示す冷凍・空調装置の冷媒回路図である。
【図２】洗浄する冷媒の状態に対する配管内の残油量の相違を示す図である。
【図３】本発明の実施の形態1の制御器の制御ブロック図。
【図４】本発明の実施の形態１の一般的な制御のフロ−チャ−ト図。
【図５】本発明の実施の形態１の過昇温、液バック防止の制御フロ−チャ−ト図。
【図６】本発明の実施の形態１を示す他の冷凍・空調装置の冷媒回路図である。
【図７】本発明の実施の形態２を示す冷凍・空調装置の冷媒回路図である。
【図８】冷媒の流れ方向の乾き度の変化を示す図である。
【図９】冷媒の流れ方向の圧力分布を示す図である。
【図１０】本発明の実施の形態２を示す他の冷凍・空調装置の冷媒回路図である。
【図１１】本発明の実施の形態２のロータリーバルブの断面図である。
【図１２】本発明の実施の形態３の負荷側熱交換器の接続台数の変化に対するトータルの流路断面積および単位断面積当りの冷媒流量の変化を示す図。
【図１３】本発明の実施の形態３の主管と枝管の接続部付近での冷媒の流動様式を示す図である。
【図１４】本発明の実施の形態３の枝管の開閉弁を閉じた場合の冷媒の挙動を示す図である。
【図１５】本発明の実施の形態４の負荷側熱交換器の接続台数の変化に対するトータルの流路断面積および単位断面積当りの冷媒流量の変化を示す図。
【図１６】本発明の実施の形態４の負荷側熱交換器の容量の変化に対する負荷側熱交換器と接続される液管またはガス管の径の変化を示す図。
【図１７】本発明の実施の形態４の負荷側熱交換器の容量の変化に対する必要冷媒流量と流量制御弁の開度の変化を示す図。
【図１８】本発明の実施の形態４の流量制御弁の圧力損失と平均冷媒流量、最小冷媒流量の関係を示す図。
【図１９】本発明の実施の形態５を示す冷凍・空調装置の冷媒回路図。
【図２０】本発明の実施の形態５における絞り装置の制御のフローチャート図。
【図２１】本発明の実施の形態６を示す冷凍・空調装置の冷媒回路図である。
【図２２】本発明の実施の形態６の冷媒の流れ方向の圧力の変化を示す図。
【図２３】本発明の実施の形態６の冷媒の流れ方向の温度の変化を示す図。
【図２４】本発明の実施の形態６の袋小路状の配管の洗浄を説明する図。
【図２５】本発明の実施の形態６の袋小路状の配管の洗浄を説明する別の図。
【図２６】本発明の実施の形態６の反転洗浄を説明冷凍・空調装置の冷媒回路図。
【図２７】本発明の実施の形態６の反転洗浄説明する冷凍・空調装置の別の冷媒回路図である。
【図２８】本発明の実施の形態７を示す冷凍・空調装置の冷媒回路図である。
【図２９】本発明の実施の形態７の油タンクより油を投入した場合と投入しない場合の残油量の時間変化を示す図。
【図３０】従来の冷凍・空調装置の冷媒回路図。
【符号の説明】
１圧縮機、１４熱源側熱交換器、１６絞り装置、１７負荷側熱交換器、２０異物回収器、２２冷媒熱交換器、３２流量制御手段、５０室外機ユニット、５１室内機ユニット、１０１液管、１０２ガス管、
１０７、１０８バイパス回路、１１０制御手段。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigeration / air-conditioning apparatus that reuses at least one of an existing extension pipe and an existing load-side heat exchanger used in the previous refrigerant, refrigeration oil (first refrigerant, refrigeration oil), The present invention relates to a refrigeration / air conditioning apparatus that is cleaned and used with a refrigerant that newly uses an air conditioner and a refrigerant of refrigeration oil (second refrigerant, refrigeration oil).
[0002]
[Prior art]
FIG. 30 is a diagram showing a method of cleaning an existing extension pipe (existing pipe) described in JP-A-11-083247. In FIG. 30, 1 is a compressor, 2 is a sub heat exchanger, 3 is a four-way valve, 4a is a first transfer heat exchanger, 4b is a second transfer heat exchanger, 5a to 5d are bridge rectifier circuits, and 6 is a feeling. A thermal expansion valve 7 is a heat exchanger, and these are connected to constitute a heat pump circuit 103. 8 is a foreign matter separator, 9a to 9d are check valves, 10, 11 and 12 are on-off valves, 101 is an existing liquid pipe, 102 is an existing gas pipe, and 13 is a tank. Configure.
[0003]
The operation of cleaning the existing liquid pipe 101 and the existing gas pipe 102 will be described. After setting the four-way valve 3 to the direction of the solid line, the compressor 1 is started. The high-temperature refrigerant gas discharged from the compressor 1 dissipates a certain amount of heat in the sub heat exchanger 2 and is condensed in the first transport heat exchanger 4a via the four-way valve 3. The condensed refrigerant liquid or gas-liquid two-phase refrigerant flows through the bridge circuit 5 a and reaches the heat exchanger 7 in the foreign matter separator 8. When the refrigerant flows through the heat exchanger 7, it heats and evaporates the cleaning agent containing the collected foreign matter that flows through the cleaning circuit, and is itself cooled and becomes a supercooled liquid refrigerant. This liquid refrigerant is squeezed to a low pressure by the temperature-sensitive expansion valve 6 to be in a low-temperature gas-liquid two-phase state, flows through the bridge circuit 5c, flows through the second transport heat exchanger 4b, and is evaporated and vaporized, via the four-way valve 3. To return to the compressor 1.
[0004]
When the refrigerant flows on the heat pump circuit 103 as described above, in the cleaning circuit 104, the cleaning agent condenses and liquefies in the second transfer heat exchanger 4b, and eventually the cleaning liquid in the second transfer heat exchanger It will be filled with. At this time, on the heat pump circuit 103, the liquid refrigerant that could not evaporate in the second transfer heat exchanger 4b is sucked into the compressor 1 and the discharge temperature is lowered. If this happens, the four-way valve 3 is switched to the direction of the broken line.
[0005]
The refrigerant flow in the heat pump circuit 103 when the four-way valve 3 is switched in the direction of the broken line will be described. The high-temperature refrigerant discharged from the compressor 1 dissipates the amount of heat that is the sub heat exchanger 2, and is condensed in the second transport heat exchanger 4 b via the four-way valve 3. The condensed refrigerant liquid or gas-liquid two-phase refrigerant flows through the bridge circuit 5 d and reaches the heat exchanger 7 in the foreign matter separator 8. When the refrigerant flows through the heat exchanger 7, it heats and evaporates the cleaning agent containing the collected foreign matter that flows through the cleaning circuit, and is itself cooled and becomes a supercooled liquid refrigerant. This liquid refrigerant is throttled to a low pressure by the temperature-sensitive expansion valve 6 to be in a low-temperature gas-liquid two-phase state, flows through the bridge circuit 5b, flows through the first transfer heat exchanger 4a, evaporates and vaporizes, and passes through the four-way valve 3. To return to the compressor 1.
[0006]
Here, in the cleaning circuit 104, the cleaning agent in the second transport heat exchanger 4b is heated and partially vaporized, and the cleaning liquid flows out from the second transport heat exchanger 4b through the check valve 9d. The cleaning liquid that has flowed out flows through the liquid pipe 101 and the gas pipe 102, dissolves foreign matters such as mineral oil in the pipe, and flows into the foreign matter separator 8. The cleaning liquid in which the foreign matters are dissolved absorbs heat from the heat exchanger 7 and vaporizes and separates the foreign matters, and then condenses and liquefies in the first transport heat exchanger 4a at a low temperature.
[0007]
By such an operation, the first transfer heat exchanger 4a and the second transfer heat exchanger 4b alternately repeat the operation of accumulating the cleaning liquid and the operation of discharging the cleaning liquid for a predetermined period, and the existing liquid pipe 101 and the gas pipe 102 are connected. Wash. After the washing operation, the washing liquid is collected in the tank 13 and the washing is finished.
[0008]
[Problems to be solved by the invention]
Since the cleaning method having such a configuration completely fills the inside of the pipe with the cleaning agent, it is necessary to prepare a large amount of the cleaning agent. In particular, in order to clean mineral oil used as refrigeration oil for chlorofluorocarbon (CFC) refrigerants and hydrochlorofluorocarbon (HCFC) refrigerants, it is necessary to use HCFC cleaners, which is an environmental problem. is there. Further, even when the cleaning agent present in the liquid state in the pipe is generally recovered, it takes time to recover the cleaning agent. Further, in a multi-type refrigeration / air-conditioning apparatus in which a plurality of indoor units are connected to one outdoor unit, a cleaning agent is supplied to each of the refrigerant pipes connected to each of the indoor units during cleaning. There is a problem that there is no flow rate control means, and there is a possibility that the connection pipes of the indoor units may be insufficiently washed due to the height difference of the indoor units and the unbalance of the connection pipe lengths.
[0009]
The present invention has been made to solve the above-mentioned problems, and in a refrigeration / air-conditioning apparatus using existing pipes and existing indoor units, the cleaning of existing pipes and existing indoor units is performed while considering the environment. It is an object of the present invention to obtain a refrigeration / air-conditioning apparatus that does not require the recovery of the agent, is easy to control, has high cleaning efficiency, is quick to clean, and has high cleaning reliability.
[0010]
[Means for Solving the Problems]
The refrigeration / air-conditioning apparatus according to the present invention includes an outdoor unit composed of a compressor, a heat source side heat exchanger, etc., an indoor unit composed of a plurality of load side heat exchangers, and the indoor unit or A throttle device provided in at least one of the outdoor unit, and a liquid pipe and a gas pipe for connecting the outdoor unit and the indoor unit, the liquid pipe, the gas pipe, and the indoor unit At least one of the first refrigerant and the refrigerating machine oil is reused. When the second refrigerant or the refrigerating machine oil different from the first refrigerant or the refrigerating machine oil is used, the control means The second refrigerant is liquid or gas-liquid two-phase, the reused part is washed with the liquid or gas-liquid two-phase second refrigerant, and the connection pipes of the plurality of load-side heat exchangers The branch pipes are washed by flowing a liquid or a gas-liquid two-phase refrigerant sequentially one by one.
It is characterized by that.
[0011]
The refrigeration / air-conditioning apparatus according to claim 2 of the present invention is the refrigeration / air-conditioning apparatus according to claim 1, comprising a cleaning circuit having a foreign matter collecting unit and a refrigerant heat exchanger.
[0012]
The refrigeration / air-conditioning apparatus according to claim 3 of the present invention is the refrigeration / air-conditioning apparatus according to claim 1 or 2, wherein the bypass circuit bypasses the load-side heat exchanger and the flow rate that controls the refrigerant flow rate of the bypass circuit. Control means are provided.
[0013]
The refrigeration and air-conditioning apparatus according to claim 4 of the present invention is the refrigeration / air-conditioning apparatus according to claim 3, wherein a rotary valve is used as the flow rate control means.
[0014]
When the branch pipes are washed one by one with liquid or gas-liquid two-phase refrigerant sequentially, a small amount of refrigerant is caused to flow through branch pipes other than the branch pipe to be washed.
[0015]
The refrigeration / air-conditioning apparatus according to the present invention includes an outdoor unit composed of a compressor, a heat source side heat exchanger, etc., an indoor unit composed of a plurality of load side heat exchangers, etc., and the indoor unit A throttle device provided in at least one of the unit or the outdoor unit, and a liquid pipe and a gas pipe for connecting the outdoor unit and the indoor unit, the liquid pipe, the gas pipe, and the indoor unit When at least one of the units is a reuse of the first refrigerant and the refrigerating machine oil, the second refrigerant and the refrigerating machine oil different from the first refrigerant and the refrigerating machine oil are used for the control. The second refrigerant is liquid or gas-liquid two-phase by means, and the reused part is washed with the liquid or gas-liquid two-phase second refrigerant, and the connecting pipe of the load-side heat exchanger. The branch pipes are divided into groups and washed with a liquid or gas-liquid two-phase refrigerant.
[0016]
Further, the pipes are grouped so that the sum of the pipe cross-sectional areas of the branch pipes to be cleaned is substantially equal.
[0017]
In addition, the load-side heat exchangers are grouped so that the sum of the capacities of the load side heat exchangers is substantially equal.
[0018]
Further, the opening degree of the flow rate control means is a fixed opening degree corresponding to the capacity of each load-side heat exchanger.
[0019]
Further, the opening degree of the flow rate control means is set to a fixed opening degree with a pressure loss equal to or higher than the pressure loss generated in the branch pipe which is a connecting pipe of the load side heat exchanger, or such a fixed throttle is provided. .
[0020]
Further, the refrigerant flow rate is calculated from pressures upstream and downstream of the flow rate control means and the opening degree of the flow rate control means, and the opening degree of the flow rate control means is corrected.
[0021]
Further, the direction of the refrigerant flow is reversed during the cleaning of the liquid pipe and the gas pipe.
[0022]
In addition, oil that is compatible with the refrigerant to be washed is allowed to flow during the washing.
[0023]
Further, in the middle of washing, oil that is incompatible or slightly compatible with the refrigerant to be washed and whose viscosity is lower than that of the remaining oil is allowed to flow.
[0024]
In addition, when flowing compatible or incompatible oil in the refrigerant to be cleaned, the liquid or gas-liquid two-phase refrigerant is flowed after circulating the oil together with the refrigerant gas.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
A refrigerant circuit diagram showing the first embodiment of the present invention is shown in FIG. In FIG. 1, 1 is a compressor, 3 is a four-way valve, 14 is a heat source side heat exchanger, 15 is an accumulator, and 106 is a bypass circuit having an on-off valve 34 for introducing hot gas. 50. Reference numerals 16a and 16b denote expansion devices, and reference numerals 17a and 17b denote load-side heat exchangers (indoor heat exchangers), which constitute indoor unit units 51a and 51b. The indoor unit is a multi-type air conditioner having two systems a and b. The outdoor unit 50 and the indoor unit 51 are connected by existing liquid pipes 101 (A to B) and existing gas pipes 102 (C to D). At this time, the pipe ends A and B of the existing liquid pipe 101 are connected to the pipe end on the heat source side heat exchanger 14 side of the outdoor unit 50 and the pipe end on the expansion device 16 side of the indoor unit 51, respectively. The pipe ends C and D of the existing gas pipe 102 are connected to the pipe end on the four-way valve 3 side of the outdoor unit 50 and the pipe end on the load side heat exchanger 17 side of the indoor unit 51, respectively. . These constitute the refrigerant circuit of the refrigeration cycle. However, the existing indoor unit 51 may be used, and the indoor unit 51 is not limited to two systems, but may be three or more systems or one system. 40 and 41 are pressure sensors for detecting the discharge pressure and suction pressure of the compressor 1, 42 is a temperature sensor for detecting the discharge temperature, and 110 is for determining and controlling the capacity of the compressor and the capacity of the heat source side heat exchanger, etc. Controller.
[0029]
In this refrigeration cycle, for example, a hydrofluorocarbon (HFC) refrigerant such as R407C
Is used. In addition, in the existing pipes 101 and 102, a mineral oil used as a lubricating oil for a refrigeration cycle using a hydrochlorofluorocarbon (HCFC) refrigerant such as R22 or a chlorofluorocarbon (CFC) refrigerant such as R502 is hydrofluorocarbon. Residual foreign matter for the (HFC) refrigerant exists in the existing pipes 101 and 102 (also present in the indoor unit 51 when the existing indoor unit 51 is used). When the remaining mineral oil is mixed with a synthetic oil such as ester oil used as a refrigeration oil for an HFC refrigerant, the solubility of the refrigeration oil in the refrigerant changes and the two-phase separation temperature rises. Lubricity deteriorates, and oil cannot be returned from the accumulator 15 to the compressor 1. For this reason, the residual amount of mineral oil which does not have such a problem is previously determined experimentally, and the residual amount of mineral oil is set as a cleaning target.
[0030]
When cleaning the existing pipes such as the liquid pipe 101 and the gas pipe 102, the refrigerant circuit is filled with a necessary amount of refrigerant such as R407C, the four-way valve 3 is switched to the direction of the solid line, and the compressor 1 is to start. The gas refrigerant discharged from the compressor 1 is heat-exchanged by the heat source side heat exchanger 14 and flows through the liquid pipe 101 as a high-pressure liquid or a two-phase refrigerant. The refrigerant that has flowed through the liquid pipe 101 becomes a low-pressure two-phase state by the expansion devices 16a and 16b, flows through the load side heat exchangers 17a and 17b and the gas pipe 102, and flows into the accumulator through the four-way valve 3.
[0031]
When the refrigerant flows in this way, the liquid or two-phase refrigerant separates the mineral oil adhering to the inner wall surface of the pipe from the wall surface by shearing force, and the separated mineral oil floats in the refrigerant liquid or gas-liquid interface. Transport while FIG. 2 compares the amount of residual oil when the inside of the pipe is cleaned in a gas state and when the pipe is cleaned in a gas-liquid two-phase state. From FIG. 2, it can be seen that the case of washing in the gas-liquid two-phase state has less residual oil and is suitable for washing. After washing the existing piping for a certain period of time, the mineral oil collected from the existing piping stays at the bottom of the accumulator 15, and is thus recovered by opening the on-off valve 35. If the accumulator 15 has liquid refrigerant, the mineral oil floats at the gas-liquid interface of the liquid refrigerant. Therefore, the bypass circuit 106 is opened by the on-off valve 34 and the hot gas is guided to the accumulator 15, and the heat source side heat exchanger 14 is turned on. It is desirable to recover the mineral oil after evaporating the liquid refrigerant of the accumulator 15 in advance by appropriately selecting the maximum capacity and operating the throttle devices 16a and 16b more narrowly.
[0032]
Therefore, after the inside of the pipe is washed with the refrigerant filled in the refrigeration cycle, the refrigeration / air conditioning operation can be performed as it is, so that the construction can be simplified and the refrigeration / air conditioning operation can be smoothly performed. Can do.
[0033]
Next, the control of the controller 110 during the cleaning operation will be described with reference to the control block diagram of FIG.
In the refrigerant circuit of FIG. 1, in order to bring the cleaning refrigerant into a liquid or two-phase state, as shown in FIG. 3, the controller 110 detects the compressor by the detected values of the pressure sensors 40 and 41 and the temperature sensor 42. 1 operating frequency, opening degree of the expansion device 16, capacity of the heat source side heat exchanger 14 (capacity of the heat exchanger itself, fan rotational speed, etc.), opening degree of the on-off valve 34 and capacity of the load side heat exchanger (heat Decide and control the capacity of the exchanger itself and fan speed.
As general controls, the pressure sensors 40 and 41 are used to set the operating frequency of the compressor 1, the opening of the expansion device 16, the capacity of the heat source side heat exchanger 14 (capacity of the heat exchanger itself, fan rotation speed, etc.) An example of control will be described.
FIG. 4 is a flowchart of this control. In FIG. 4, the capacity AK14 of the heat source side heat exchanger 14 is set to a preset capacity in Step 1 (hereinafter referred to as S1). The set capacity of the AK 14 may be appropriately changed according to conditions such as the outside air temperature and the refrigerant pipe length. In S2, the pressure sensors 40 and 41 detect the discharge pressure Pd of the compressor 1 and the suction pressure Ps of the compressor. A difference ΔPd between the target discharge pressure Pdm and the discharge pressure Pd and a difference ΔPs between the target suction pressure Psm and the suction pressure Ps set in advance in S3 are calculated. Based on these calculated values, a correction value ΔFcomp of the compressor operating frequency and a correction value ΔA16 of the expansion device 16 are calculated in S4, and each control is performed based on the calculated values, and the process returns to S1.
Note that a, b, c, and d in FIG. 4 are constants.
[0034]
Further, in order to prevent an excessive increase in the discharge temperature of the compressor and prevention of liquid back, the following control is performed as shown in the flowchart of FIG. In S <b> 11, the compressor discharge temperature Td is detected by the temperature sensor 42, and the compressor discharge pressure Pd is detected from the pressure sensor 42. In S12, an upper limit value Tdmax of the discharge temperature set in advance and the detected value Td of the discharge temperature are compared. If Td <Tdmax, the process proceeds to S13, and the capacity of the heat source side heat exchanger 14 is not changed. When Td> Tdmax, the process proceeds to S14, and the correction value ΔAK14 of the capacity of the heat source side heat exchanger 14 is calculated and controlled according to the difference between Tdmax and Td. In S15, Td−Tsat (the degree of discharge superheat, and the saturation temperature Tsat is estimated from the compressor discharge pressure Pd) is compared with a preset minimum value of discharge superheat ΔTSH. If Td−Tsat> ΔTSH, Proceeding to S16, the capacity of the heat source side heat exchanger 14 is not changed. In the case of Td−Tsat <ΔTSH, it is determined that the liquid back to the compressor is large, and the process proceeds to S17, where the capacity AK14 of the heat source side heat exchanger 14 is compared with the preset minimum value AKmin, and AK14> AKmin. Moves to S18, and obtains and controls the correction value ΔAK14 of the capacity of the heat source side heat exchanger 14. When AK14 <AKmin, the routine proceeds to S19, where a correction value ΔA34 for the opening degree of the on-off valve 34 is obtained and controlled.
Note that e, f, and g in FIG. 5 are constants.
[0035]
The above is the case where the existing indoor unit 51 can be cleaned along with the cleaning of the existing liquid pipe 101 and the existing gas pipe 102 (if only the indoor unit 51 is already installed, the indoor unit 51 is cleaned). However, when the indoor unit 51 is newly installed, an indoor unit bypass circuit 107 that bypasses the indoor unit 51 is installed as shown in FIG. The flow control valve 32 is opened, the expansion devices 16a and 16b and the indoor heat exchangers 17a and 17b are bypassed, the liquid pipe 101 and the gas pipe 102 are washed, the on-off valves 30 and 31 are opened, and the flow control valve 32 is opened. If it is closed, it is possible to newly install the indoor unit 51 and clean only the existing liquid pipe 101 and gas pipe 102. Regarding the control of the controller 110 for bringing the cleaning refrigerant into a liquid or two-phase state during the cleaning operation, in the refrigerant circuit of FIG. 6, the controller 110 detects the detected values of the pressure sensors 40 and 41 and the temperature sensor 42. Thus, the operating frequency of the compressor 1, the capacity of the heat source side heat exchanger 14 (capacity of the heat exchanger itself, fan rotation speed, etc.) and the opening degree of the on-off valve 34 are determined and controlled.
[0036]
In this embodiment, an example in which an HFC refrigerant is used as a refrigerant to be filled in the refrigeration cycle has been described. However, the refrigerant is a refrigerant that performs refrigeration and air conditioning operation as it is, and is an HFC refrigerant that is environmentally friendly. For example, a propane-based or isobutane-based hydrocarbon (HC) -based refrigerant may be used.
Although the expansion device 16 is provided on the indoor unit unit 51 side, it may be provided downstream of the heat source side heat exchanger 14 on the outdoor unit unit 50 side.
[0037]
Embodiment 2. FIG.
FIG. 7 is a refrigerant circuit diagram showing Embodiment 2 of the present invention. In the figure, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 7, 19 is an oil separator, 20 is a foreign matter collector, 21 is a decompressor, 22 is a refrigerant heat exchanger, 23 is an oil return circuit, and 24, 25, 26, 27, 28, and 29 are on-off valves. These are connected by piping to constitute a cleaning unit 52 which is a cleaning circuit. The cleaning unit 52 is pipe-connected between the pipe end A of the existing liquid pipe 101, the pipe end C of the existing gas pipe 102, and both pipe ends of the outdoor unit 50.
[0038]
When cleaning the existing liquid pipe 101 and gas pipe 102, the refrigerant circuit is filled with a necessary amount of refrigerant, the four-way valve 3 is switched to the direction of the solid line, the on-off valves 26 and 29 are closed, and compression is performed. The machine 1 is started. The gas refrigerant discharged from the compressor 1 exchanges heat with the heat source side heat exchanger 14, dissipates an appropriate amount of heat, enters the washing unit 52 through the on-off valve 24, and reaches the oil separator 19. In the oil separator 19, the refrigerating machine oil newly filled in the unit is separated, and the separated refrigerating machine oil is returned to the outdoor unit 50 through the oil return circuit 23 and the on-off valve 27. The gas refrigerant from which the oil has been separated by the oil separator 19 is condensed by the refrigerant heat exchanger 22 to become a liquid or gas-liquid two-phase refrigerant, and flows through the existing liquid pipe 101 via the on-off valve 25. The refrigerant that has flowed through the liquid pipe 101 becomes a low-pressure two-phase state by the expansion devices 16a and 16b, flows through the load side heat exchangers 17a and 17b and the existing gas pipe 102, and shears the liquid or two-phase refrigerant. The mineral oil adhering to the inner wall surface of the pipe is separated from the wall surface by force, and the separated mineral oil is transported while floating in the refrigerant liquid or the gas-liquid interface. The gas-liquid two-phase refrigerant that has flowed through the existing gas pipe 102 enters the cleaning unit 52 through the on-off valve 28, is slightly throttled by the decompression device 21, and then flows out of the oil separator 19 by the refrigerant heat exchanger 22. It exchanges heat with the refrigerant and evaporates itself and flows to the foreign material recovery device 20. In the foreign matter recovery device 20, the mineral oil recovered from the existing liquid pipe 101 and gas pipe 102 is separated, and only the refrigerant is returned to the outdoor unit 50 via the on-off valve 27.
[0039]
Therefore, it is possible to collect the deteriorated refrigeration oil remaining in the existing piping and prevent the recovered refrigeration oil from being scattered again in the refrigerant circuit after washing. Further, since the refrigerant in the liquid or gas-liquid two-phase state required during the cleaning operation can be obtained by using the refrigerant heat exchanger 22, the heat source side heat exchanger 14 and the load side heat exchanger 17 fan Control of driving power and fan is unnecessary, economical and easy to control.
[0040]
8 shows a change in the dryness in the flow direction of the refrigerant when the refrigerant flows from the liquid pipe 101 to the gas pipe 102. FIG. 9 shows the refrigerant in the direction from the liquid pipe 101 to the gas pipe 102. The distribution of the pressure in the pipe in the flow direction of the refrigerant when flowing is shown. 8 that the change in the dryness of the refrigerant in the liquid pipe 101 is large and the change in the dryness in the gas pipe 102 is small. Furthermore, it can be seen from FIG. 9 that the change in pressure is large in the liquid pipe 101. In general, the pressure loss in the pipe at the same flow rate becomes smaller as the degree of dryness becomes smaller. Therefore, if the degree of dryness of the refrigerant is reduced in the liquid pipe 101 where the pipe is thin and the flow resistance is larger than that of the gas pipe 102, the pressure loss is reduced. Becomes smaller. When the refrigerant filling amount filled in the refrigeration cycle is constant, the average dryness in the pipe when flowing from the liquid pipe 101 side to the gas pipe 102 side is when the refrigerant flows from the gas pipe 102 side to the liquid pipe 101 side. The pressure loss is smaller than when the refrigerant is flowed from the gas pipe 102 to the liquid pipe 101 by flowing the refrigerant in the direction from the liquid pipe 101 to the gas pipe 102. be able to. Therefore, by washing from the liquid pipe 101 to the gas pipe 102, the pressure loss can be reduced by reducing the dryness of the refrigerant in the liquid pipe 101 that governs the pressure loss of the entire pipe, and the washing is performed by increasing the refrigerant flow rate. Time can be shortened.
[0041]
The above is a case where the existing indoor unit 51 can be cleaned along with the cleaning of the existing liquid pipe 101 and the existing gas pipe 102 (if only the indoor unit 51 is already installed, the indoor unit 51 is cleaned). However, when newly installing the indoor unit 51, as shown in FIG. 10, an indoor unit bypass circuit 108 for bypassing the load-side heat exchanger 17 and the expansion device 16 is provided. A flow control valve 32 serving as a flow control means is provided, and an open / close valve 30 is provided between the existing liquid pipe 101 and the throttle 16, and an open / close valve 31 is provided between the existing gas pipe 102 and the load side heat exchanger 17. Thus, it is possible to newly install the indoor unit 51 and clean only the existing liquid pipe 101 and gas pipe 102.
[0042]
Further, an indoor unit bypass circuit 108 that bypasses the load-side heat exchanger 17 and the expansion device 16, a flow control valve 32 provided on the bypass pipe 108, an on-off valve 30 between the liquid pipe 101 and the expansion unit 16, When the rotary valve shown in FIG. 11 is used instead of the flow control valve 32 and the on-off valves 30 and 31 in the bypass unit 53 configured by the on-off valve 31 between the gas pipe 102 and the load side heat exchanger 17, The reliability of cleaning can be increased. That is, the rotary valve is configured by the drive motor 43, the gear 44, the first valve 45, the second valve 46, and the like, and the opening degree of the clamping portion 47 is adjusted by the lift amount of the first valve 45, and between the pipes 103b and 103d. Change the channel resistance. At this time, the pipes 103b and 103d are completely separated from the pipes 103a and 103c. When the lower surface of the first valve 45 and the upper surface of the second valve 46 are in contact with each other, the first valve 45 and the second valve 46 rotate together to close the pipes 103b and 103d, and the pipes 103a and 103b. Forms a flow path through the hole 48, and the pipes 103 c and 103 d form a flow path through the hole 49. The pipe 103a of this rotary valve is connected to the gas pipe side of the load side heat exchanger, and the pipe 103c is connected to the expansion device 16. One end of the indoor unit bypass circuit 108 is connected to the pipe 103b and the other end is connected to 103d.
[0043]
At the time of cleaning, the pipe 103b and the pipe 103d are connected via the pinching portion 47, and the liquid pipe 101 and the gas pipe 102 are washed while adjusting the opening degree of the pinching portion 47. Moreover, after completion | finish of washing | cleaning, the said 1st valve 44 is lifted, the 1st valve 45 and the 2nd valve 46 are rotated, and while piping 103a and piping 103b are distribute | circulated, piping 103c and piping 103d are distribute | circulated. Normal refrigeration and air conditioning operation is performed by As a result, the bypass unit 53 can be manufactured at a low cost, and the main refrigerant pipes (main pipes connected to the existing liquid pipe 101 and the existing gas pipe 102) when the on-off valves 30 and 31 are closed and cleaned are used. It is possible to prevent accumulation of foreign matters in the cecal piping from the branching portion (Ea, Eb, Fa, Fb) to the indoor unit bypass circuit 108 in the branch pipe to the on-off valves 30 and 31, and to improve cleaning reliability. it can.
This rotary valve can also be used in the refrigerant circuit of FIG.
[0044]
In addition, after cleaning the existing pipes 101 and 102 and the indoor unit 51, the cleaning unit 52 closes the on-off valves 24, 25, 27, and 28, and closes the on-off valves 24, 25, 27, and 28 of the refrigeration / air-conditioning apparatus. It may be removed when left as a part (the on-off valves 26 and 29 are left open) and used when cleaning the existing pipes of other refrigeration / air conditioners.
Also in this embodiment, the expansion device 16 is provided on the indoor unit unit 51 side. However, the expansion device 16 may be provided on the outdoor unit unit 50 side and downstream of the heat source side heat exchanger 14.
Also in the present embodiment, the cleaning refrigerant is controlled to be liquid or gas-liquid two-phase refrigerant by the controller.
[0045]
Embodiment 3 FIG.
The third embodiment relates to the cleaning of the plurality of indoor unit units 51, and the other points are the same as those of the first and second embodiments. 12 shows a refrigerant circuit configuration as shown in FIG. 1 and FIG. 10, and connection pipes (the existing liquid pipe 101 and the existing gas pipe) of the load side heat exchanger 17 with respect to changes in the number of connected load side heat exchangers 17. The branch pipes connected to the load side heat exchanger 17 are connected pipes between the main pipes connected to 102 respectively, and the change in the refrigerant flow rate per total cross-sectional area and unit cross-sectional area is shown. As shown in FIG. 12, the total cross-sectional area of the pipes connected to the load-side heat exchanger 17 increases as the number of connected load-side heat exchangers 17 increases. As a result, each of the plurality of pipes flows. Since the refrigerant flow rate decreases, it is possible to secure the refrigerant flow rate necessary for washing by washing each pipe.
[0046]
FIG. 13 shows the state of the refrigerant flow during cleaning near the connection between the main pipe 111 and the branch pipe 112 connecting each indoor unit 51. Here, the main pipe 111 is a pipe connected to the gas pipe 102, for example, and a plurality of load-side heat exchangers 17 are branched. The branch pipe 112 is a pipe that connects the load-side heat exchanger 17 to the main pipe. 111 is a pipe connected to 111. As shown in FIG. 13, when the gas-liquid two-phase refrigerant moves up the branch pipe 112 and flows into the main pipe 111, the flow pattern in the branch pipe 112 is a flow pattern such as a bubble flow or an annular flow. For this reason, when the on-off valves 30 and 31 are closed and the flow of the branch pipe 112 is stopped, the refrigerant gas rises by buoyancy, and the refrigerant liquid flows from the main pipe 111 into the branch pipe 112 as shown in FIG. At this time, the pipes for closing the on-off valves 30 and 31 are not completely closed, but a little refrigerant flow is allowed to flow slightly without opening the on-off valves 30 and 31, thereby preventing foreign substances from flowing back to the washing pipe. it can. In addition, the refrigerant shortage due to the stagnation of the refrigerant in the piping that closes the on-off valves 30 and 31 can be solved.
[0047]
Further, when cleaning a plurality of pipes one by one, the pipes may be washed one by one for a predetermined time. However, when the first washed branch pipe is compared with the last washed branch pipe, the first washed branch pipe is cleaned. Since the pipe has a larger amount of residual oil upstream of the branch pipe, there is a greater possibility that the mineral oil flowing in the refrigerant will reattach to the branch pipe being washed. It is possible to wash each pipe several times, such as washing the next pipe and then washing the first pipe again. By doing this, each branch pipe can be washed. Variations can be reduced.
[0048]
Embodiment 4 FIG.
FIG. 15 shows a total cross-sectional area and unit cross-sectional area of the connecting pipe (branch pipe) of the load-side heat exchanger 17 with respect to changes in the number of connected load-side heat exchangers 17 in the refrigerant circuit shown in FIGS. The change in the refrigerant flow rate per unit is shown. Here, assuming that the diameters of the branch pipes connected to the load-side heat exchanger 17 are all equal, when washing the pipes, the pipes that can secure the refrigerant flow rate necessary for washing are grouped rather than washing one by one. Thus, the cleaning time can be shortened by cleaning each group. That is, the number of refrigerants that can be tested in the test room in advance and set the flow rate of refrigerant necessary for cleaning, that is, the required flow rate of refrigerant per unit cross-sectional area is obtained from FIG. By setting n and cleaning n units as one group, that is, the pipe cross-sectional area that provides the refrigerant flow rate necessary for cleaning, and the sum of the cross-sectional areas of the pipes to be grouped becomes equal. As described above, by washing the branch pipes into groups (in some cases, one branch may be used as one group), a plurality of branch pipes can be washed at a time, so that the washing time can be shortened.
Further, since the capacity of the load-side heat exchanger 17 and the pipe diameter connected to the load-side heat exchanger 17 have a one-to-one relationship as shown in FIG. 16, a refrigerant flow rate necessary for cleaning can be obtained. Even if the branch pipes are grouped so that the sum of the capacities of the load-side heat exchangers 17 to be grouped is equal to the pipe cross-sectional area, the same effect can be obtained.
However, even if the sum of the cross-sectional areas of the pipes to be grouped and the sum of the capacities of the load-side heat exchangers 17 are not equal, they may be grouped so as to ensure the refrigerant flow rate necessary for cleaning.
[0049]
In addition, the refrigerant flow rate required for cleaning varies depending on the unbalance of pipe length and pipe diameter, cleaning time, refrigerant flow rate, oil type, mineral oil viscosity, and so on. It is desirable to select the correct number of groups.
[0050]
FIG. 16 shows a comparison between the capacity of each load-side heat exchanger 17 and the diameter of a liquid pipe or a gas pipe branch pipe connected to the load-side heat exchanger 17. As shown in FIG. 16, the diameter of the pipe to be connected is determined for each predetermined range. Therefore, as shown in FIG. 16, a one-to-one relationship is established between the capacity of the load-side heat exchanger 17 and the pipe diameter, and as shown in FIG. Since there is a one-to-one relationship between the capacity and the refrigerant flow rate required for cleaning, if the opening degree of the flow control valve 32 is a fixed opening degree determined by the capacity of the load-side heat exchanger 17, the refrigerant according to the pipe diameter Since flow rate distribution can be performed, refrigerant distribution necessary for cleaning can be performed for each pipe. That is, by setting the opening degree of the flow rate control valve 32 to a fixed opening degree corresponding to the capacity of the load side heat exchanger 17 in advance, the refrigerant flow rate necessary for cleaning can be obtained without checking the construction state of the piping. The refrigerant distribution amount can be controlled. Therefore, the imbalance of the refrigerant flow rate distributed to each branch pipe in each group can be reduced, and the cleaning reliability can be easily ensured.
The same effect can be obtained even if a fixed throttle other than the flow control valve 32 is provided on the branch pipe.
[0051]
FIG. 18 shows an average in the group with respect to a change in pressure loss in the flow rate control valve 32 which is a flow rate control means when different pipe lengths are grouped into the same group. The refrigerant flow rate and the change in the minimum flow rate in the group are shown. As shown in FIG. 18, the pressure loss at the flow rate control valve 32 increases, and the minimum flow rate gradually approaches the average flow rate. The pressure loss ΔP (ΔP value indicated by a solid line in the figure) is almost equal to the pressure loss of the branch pipe. ), It is possible to set the average flow rate to about two-thirds or more. Accordingly, it is possible to reduce unbalance of the refrigerant flow rate distributed to each branch pipe in each group, and to easily ensure the reliability of cleaning.
In addition, if the pressure loss which can obtain the refrigerant | coolant flow volume required for washing | cleaning is calculated | required previously, the pressure loss applied with the flow control valve 32 may be equal to or less than the pressure loss of the branch pipe. Furthermore, even if the pipe diameters of the pipes to be grouped are different, if a pressure loss ΔP substantially equal to the pressure loss of the branch pipes is applied, the unbalance of the refrigerant flow amount distributed to each branch pipe is reduced. The reliability of cleaning can be easily secured.
[0052]
Embodiment 5 FIG.
FIG. 19 is a refrigerant circuit diagram showing Embodiment 5 of the invention. In the figure, 1 is a compressor, 3 is a four-way valve, 14 is a source side heat exchanger, and 15 is an accumulator, and these constitute an outdoor unit 50. Reference numeral 16 denotes a throttle device which is a flow rate control means, and reference numeral 17 denotes a load side heat exchanger, which constitutes an indoor unit. 101 is a liquid pipe that is an existing pipe that connects the outdoor unit 50 and the indoor unit, and 102 is a gas pipe that is an existing pipe that connects the outdoor unit 50 and the indoor unit. 19 is an oil separator, 20 is a foreign matter collector, 21 is a decompressor, 22 is a refrigerant heat exchanger, 23 is an oil return circuit, 24, 25, 26, 27, 28, and 29 are on-off valves. A cleaning unit 52 is configured. Reference numerals 34 and 35 denote temperature sensors on the inlet side and the outlet side of the expansion device 16.
[0053]
When cleaning the existing pipes of the liquid pipe 101 and the gas pipe 102, a necessary amount of refrigerant is sealed in the refrigerant circuit, the four-way valve 3 is switched to the direction of the solid line, the on-off valves 26 and 29 are closed, and compression is performed. The machine 1 is started. The gas refrigerant discharged from the compressor 1 is heat-exchanged by the heat source side heat exchanger 14, where an appropriate amount of heat is radiated to the oil separator 19. In the oil separator 19, the refrigerating machine oil newly filled in the unit is separated, and the separated refrigerating machine oil is returned to the outdoor unit 50 through the oil return circuit 23. The gas refrigerant from which the oil has been separated by the oil separator 19 is condensed by the refrigerant heat exchanger 22 and becomes a liquid or gas-liquid two-phase refrigerant and flows through the liquid pipe 101. The refrigerant that has flowed through the liquid pipe 101 becomes a low-pressure two-phase state by the expansion devices 16a and 16b and flows through the load-side heat exchangers 17a and 17b and the gas pipe 102, and by the shearing force of the liquid or two-phase refrigerant. The mineral oil adhering to the inner wall surface of the pipe is separated from the wall surface, and the separated mineral oil is transported while floating in the refrigerant liquid or the gas-liquid interface. The gas-liquid two-phase refrigerant that has flowed through the gas pipe 102 is slightly squeezed by the decompression device 21 and then exchanges heat with the high-temperature refrigerant that has flowed out of the oil separator 19 by the refrigerant heat exchanger 22. It flows to the foreign material recovery device 20. In the foreign material recovery device 20, the mineral oil recovered from the existing liquid pipe 101 and gas pipe 102 is separated, and only the refrigerant is returned to the outdoor unit 50.
[0054]
FIG. 20 is a flowchart showing a method for setting the opening degree of the expansion devices 16a and 16b. A method for setting the opening degree of the expansion devices 16a and 16b will be described with reference to FIG. In the following description, the subscript i indicates the i-th of the plurality of indoor units, Pi1 and Pi2 are the pressure on the inlet side and the outlet side of the expansion device 16, and the saturation pressure is determined from the detected values of the temperature sensors 34 and 35. Estimate as Ai is the opening of the expansion device 16, and Ci and ki are coefficients (constants).
In FIG. 20, in steps 1 (hereinafter referred to as S1, S2,...), Pressures Pi1 and Pi2 are estimated from detection values of the temperature sensors 34 and 35. In S2, the differential pressure ΔPi = Pi1-Pi2 is calculated. In S3, the refrigerant flow rate G i = Ci · Ai · √ΔPi per unit section of the pipe flowing through each indoor heat exchanger is calculated. In S4, the average value of the refrigerant flow rate per unit cross-sectional area of the piping flowing through each indoor unit is calculated. In S5, a difference ΔG i between the average value Gm of the refrigerant flow rate per unit cross-sectional area of the pipe flowing through each indoor unit and the previously calculated refrigerant flow rate Gi is calculated. In S6, the change value Ai ′ of the opening degree of the expansion device 16 is calculated and controlled. In S7, the cleaning operation end time is determined. When the cleaning end time is reached, the control of the expansion device 16 is ended. If the cleaning end time is not reached, the opening degree of the expansion device 16 is set, and the process returns to S1.
[0055]
As described above, by setting the opening degree of the expansion device 16, the uneven distribution of refrigerant to the branch pipes due to differences in pipe length and pipe diameter is reduced, and each group according to pipe length, pipe diameter, height difference, etc. It is possible to correct the imbalance of the refrigerant distribution amount to the pipe in the interior with high accuracy and to improve the reliability of cleaning.
The refrigerant circuit diagram of FIG. 19 is an example in which the load-side heat exchanger 17 has no indoor unit bypass piping. However, when the bypass piping 108 is provided as shown in FIG. Control is performed in the same manner as the expansion device 16 by the pressure before and after that.
[0056]
Embodiment 6 FIG.
FIG. 21 is a refrigerant circuit diagram showing Embodiment 6 of the present invention. In the figure, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 21, 19 is an oil separator, 20 is a foreign matter collector, 21 is a pressure reducing device, 22 is a refrigerant heat exchanger, 23 is an oil return circuit, and 24, 25, 26, 27, 28, and 29 are on-off valves. These constitute the cleaning unit 52.
[0057]
When cleaning the existing liquid pipe 101 and gas pipe 102, a necessary amount of refrigerant is sealed in the refrigerant circuit, the four-way valve 3 is switched to the direction of the broken line, the on-off valves 26 and 29 are closed, and compression is performed. The machine 1 is started. The gas refrigerant discharged from the compressor 1 reaches the oil separator 19 via the open / close valve 27 via the four-way valve. In the oil separator 19, the refrigerating machine oil newly filled in the unit is separated, and the separated refrigerating machine oil is returned to the outdoor unit 50 through the oil return circuit 23 and the on-off valve 24. The gas refrigerant from which the oil has been separated by the oil separator 19 is condensed by the refrigerant heat exchanger 22 to become a liquid or gas-liquid two-phase refrigerant, and flows through the gas pipe 102 via the on-off valve 28. The refrigerant that has flowed through the gas pipe 102 bypasses the load-side heat exchangers 17a and 17b and the expansion devices 16a and 16b, flows through the bypass units 53a and 53b, is slightly throttled by the flow control valves 32a and 32b, and then the liquid pipe The mineral oil adhering to the inner wall surface of the pipe is separated from the wall surface by the shearing force of the liquid or two-phase refrigerant while flowing through 101, and the separated mineral oil is transported while floating in the refrigerant liquid or the gas-liquid interface. The gas-liquid two-phase refrigerant that has flowed through the liquid pipe 101 enters the cleaning unit 52 through the on-off valve 25, is slightly throttled by the decompression device 21, and then flows out of the oil separator 19 by the refrigerant heat exchanger 22. The heat exchanges with itself and evaporates and flows to the foreign matter collector 20. In the foreign material recovery device 20, the mineral oil recovered from the liquid pipe 101 and the gas pipe 102, which are existing pipes, is separated, and only the refrigerant is returned to the outdoor unit 50 via the on-off valve 24.
[0058]
FIG. 22 shows changes in the refrigerant pressure with respect to the flow direction of the refrigerant. From FIG. 22, it can be seen that the pressure is almost constant at 102 parts of the gas pipe, and the pressure is greatly reduced at the liquid pipe 101 part. As a result, it can be seen that the temperature distribution in the refrigerant flow direction is uniformly high-pressure saturation temperature in the gas pipe 102 as shown in FIG.
[0059]
As a result, since a high-temperature, high-pressure gas-liquid two-phase refrigerant flows through the gas pipe 102, the viscosity of the mineral oil remaining in the gas pipe 102 can be reduced and moved smoothly by the shearing force of the refrigerant. Time can be reduced.
[0060]
In branching of a branch pipe using a branch pipe by a header or the like, there is a case where a pipe having a small path as shown in FIGS. 24 and 25 exists. At this time, when the flow direction of the refrigerant flows vertically toward the front end of the bag path as shown in FIG. 24, the cleaning refrigerant does not reach the front end of the bag path sufficiently, and the cleaning becomes insufficient. Therefore, as shown in FIG. 25, it is desirable to clean the bag path by flowing the refrigerant in parallel toward the front end of the bag path and letting the liquid refrigerant fly to the end of the path by the inertia of the liquid refrigerant. However, in the case of existing refrigerant piping, the pipe construction state may not be known in advance, so a four-way valve 35 is arranged as shown in FIG. 26 (FIG. 27) (four-way valve in the refrigerant circuit diagram of FIG. 21). 35), when the flow direction of the refrigerant is reversed as shown in FIG. 26 to FIG. 27 or FIG. 27 to FIG. Even when the pipe is washed, the washing can be sufficiently washed, so that the washing reliability is improved.
Further, it is desirable that the heat source side heat exchanger 14 is selected and used on either the high pressure side or the low pressure side in view of heat absorption or heat dissipation in the existing piping.
[0061]
Embodiment 7 FIG.
FIG. 28 is a refrigerant circuit diagram showing Embodiment 7 of the present invention. In the figure, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 28, 36, 37, and 38 are on-off valves, 39 is an oil tank, and piping etc. may be used. Inside the oil tank 39, oil compatible with the refrigerant liquid is sealed. Here, the oil to be sealed in the oil tank 39 may be the same as or different from the refrigerating machine oil of the compressor 1 built in the outdoor unit 50.
[0062]
When cleaning the existing liquid pipe 101 and gas pipe 102, the refrigerant circuit is filled with a necessary amount of refrigerant, the four-way valve 3 is switched to the direction of the solid line, and the on-off valves 26, 29, 37, 38 are It is closed, the on-off valve 36 is opened, and the compressor 1 is started. The gas refrigerant discharged from the compressor 1 is heat-exchanged by the heat source side heat exchanger 14, where an appropriate amount of heat is radiated to the oil separator 19. In the oil separator 19, the refrigerating machine oil newly filled in the outdoor unit 50 is separated, and the separated refrigerating machine oil is returned to the outdoor unit 50. The gas refrigerant from which the oil has been separated by the oil separator 19 is condensed by the refrigerant heat exchanger 22 and becomes a liquid or gas-liquid two-phase refrigerant and flows through the liquid pipe 101. The refrigerant that has flowed through the liquid pipe 101 bypasses the expansion devices 16a and 16b and the load side heat exchangers 17a and 17b, flows through the bypass units 53a and 53b, and is slightly throttled by the flow control valves 32a and 32b, and then the gas pipe The mineral oil adhering to the inner wall surface of the pipe is separated from the wall surface by the shearing force of the liquid or two-phase refrigerant while flowing through 102, and the separated mineral oil is transported while floating in the refrigerant liquid or the gas-liquid interface. The gas-liquid two-phase refrigerant that has flowed through the gas pipe 102 is slightly squeezed by the decompression device 21 and then exchanges heat with the high-temperature refrigerant that has flowed out of the oil separator 19 by the refrigerant heat exchanger 22. It flows to the foreign material recovery device 20. In the foreign material recovery device 20, the mineral oil recovered from the existing liquid pipe 101 and gas pipe 102 is separated, and only the refrigerant is returned to the outdoor unit 30.
[0063]
In the cleaning, the oil tank 39 is closed by closing the on-off valve 36 and opening the on-off valves 37 and 38 at a time when it is estimated that the amount of mineral oil remaining in the pipe becomes below a certain value after a certain time. The internal oil is guided to the liquid pipe 101 and the gas pipe 102 which are existing pipes. As a result, the oil flowing out from the oil tank 39 and the oil remaining in the liquid pipe 101 and the gas pipe 102 are mixed, the solubility in the refrigerant liquid is increased, and the mineral oil remaining in the form of a liquid film on the inner surface of the pipe becomes the liquid refrigerant. The oil is dissolved in the liquid refrigerant together with the oil compatible with the oil, so that the recovery rate of the mineral oil is increased. FIG. 29 is a diagram showing this effect, with the horizontal axis representing the cleaning time and the vertical axis representing the amount of mineral oil remaining in the pipe. In the figure, line A is the amount of residual oil when no oil compatible with the liquid refrigerant flows from the oil tank 39, and line B is compatible with the liquid refrigerant from the oil tank 39 after an appropriate time after the start of cleaning. The amount of residual oil is shown when a fresh oil is poured. As can be seen from FIG. 29, when the oil compatible with the liquid refrigerant is caused to flow from the oil tank 39, the mineral oil remaining in the pipe is compared with the case where the oil compatible with the liquid refrigerant is not allowed to flow from the oil tank 39. It can be seen that the cleaning time until the same amount becomes the same amount is less than half. Accordingly, by flowing oil compatible with the liquid refrigerant from the oil tank 39 at an appropriate time, there is an effect of shortening the time for washing to the target residual oil amount. Here, the appropriate time is, for example, the time until the oil adhering to the inner wall surface of the pipe by the cleaning becomes a droplet or film.
[0064]
Here, the amount of oil to be filled in the oil tank 39 in advance is determined based on the amount of oil remaining in the liquid pipe and the gas pipe when oil is supplied from the oil tank 39 during cleaning. When the remaining oil is mixed with the oil remaining in the liquid pipe and the gas pipe, the amount of the mixed oil is such that a certain degree of solubility can be secured in the refrigerant liquid.
[0065]
Further, when the liquid pipe 101 and the gas pipe 102 are long, if the oil sealed in the oil tank 39 is oil compatible with the refrigerant liquid, the mineral oil in the liquid pipe and the gas pipe and the compatible oil Since the liquid refrigerant is dissolved in the compatible oil and the compatible oil is diluted before the oil directly contacts, the effect of dissolving the mineral oil remaining in the pipe may be reduced. In this case, the oil sealed in the oil tank 39 is made incompatible with the refrigerant liquid, and the viscosity of the oil is made smaller than the viscosity of the mineral oil remaining in the pipe, thereby removing the incompatible oil. Or even if it flows with a gas-liquid two-phase refrigerant, the refrigerant does not dissolve in the incompatible oil, and it becomes possible to make the mixed oil by directly contacting the incompatible oil with the mineral oil in the liquid pipe and the gas pipe. Furthermore, this mixed oil is smaller than the viscosity of the mineral oil originally remaining in the pipe and has a high fluidity, so that the mineral oil in the liquid and gas pipes can be quickly recovered and the washing time can be shortened. Can do.
[0066]
Further, when the oil sealed in the oil tank 39 is introduced into the liquid pipe 101 and the gas pipe 102, the refrigerant heat exchanger 22 is bypassed, and the oil sealed in the oil tank 39 together with the gas refrigerant is supplied to the liquid pipe 101 and the gas pipe. By guiding to 102, the oil in the oil tank 39 flows in the form of a thin film on the inner wall surface of the liquid pipe 101 and the gas pipe 102, and is uniformly brought into contact with the mineral oil existing in the liquid pipe 101 and the gas pipe 102. Therefore, the mixed oil of the mineral oil in the liquid pipe 101 and the gas pipe 102 and the oil sealed in the oil tank 39 is recovered by using a gas-liquid two-phase refrigerant, so that it is compatible in the oil tank. When the oil is filled, the washing speed of the mineral oil can be increased by dissolving in the liquid refrigerant. In addition, when the oil tank is filled with an incompatible oil smaller than the viscosity of the mineral oil remaining in the liquid pipe 101 and the gas pipe 102, the viscosity of the mixed oil of the mineral oil and the incompatible oil is lowered to improve the fluidity. By improving it, it becomes possible to increase a cleaning speed and to improve the reliability of cleaning.
[0067]
【The invention's effect】
As described above, according to the refrigeration / air-conditioning apparatus of the present invention, an outdoor unit composed of a compressor, a heat source side heat exchanger, etc., and an indoor unit unit composed of a plurality of load side heat exchangers, etc. A throttle device provided in at least one of the indoor unit or the outdoor unit, and a liquid pipe and a gas pipe for connecting the outdoor unit and the indoor unit, the liquid pipe and the gas pipe, In addition, at least one of the indoor unit units is a reuse of the first refrigerant and the refrigerating machine oil, and the second refrigerant and the refrigerating machine oil different from the first refrigerant and the refrigerating machine oil are used. In this case, the control means converts the second refrigerant into a liquid or gas-liquid two-phase, cleans the reused portion with the liquid or gas-liquid two-phase second refrigerant, and also performs the plurality of load-side heat exchanges. vessel The branch pipes, which are the connection pipes, are cleaned by sequentially flowing liquid or gas-liquid two-phase refrigerant one by one. As a result, the deteriorated first refrigerating machine oil can be quickly washed and recovered, and can be used as a normal refrigeration / air conditioner as it is after the washing operation, so that the construction can be simplified.
In addition, since the branch pipes that are connection pipes of the load-side heat exchanger are washed one by one by sequentially flowing liquid or gas-liquid two-phase refrigerant, there is no shortage of refrigerant flow for washing the branch pipes. Even when the sum of the cross-sectional areas of the branch pipes connected to each load-side heat exchanger is larger than the cross-sectional area of the liquid pipe or gas pipe connecting the outdoor unit and the indoor unit, It is possible to secure the refrigerant flow rate necessary for cleaning and improve the reliability of cleaning.
[0068]
The refrigeration / air-conditioning apparatus according to claim 2 of the present invention is the refrigeration / air-conditioning apparatus according to claim 1, which is provided with a cleaning circuit having a foreign matter recovery unit and a refrigerant heat exchanger, and therefore remains in existing piping. It is possible to collect the deteriorated refrigeration oil and prevent the recovered refrigeration oil from being scattered again in the refrigerant circuit after washing. In addition, since the liquid refrigerant required during the cleaning operation can be obtained by using a refrigerant heat exchanger, fan driving power and fan control are unnecessary, economical, and easy to control. .
[0069]
The refrigeration / air-conditioning apparatus according to claim 3 of the present invention is the refrigeration / air-conditioning apparatus according to claim 1 or 2, wherein the bypass circuit bypasses the load-side heat exchanger and the flow rate that controls the refrigerant flow rate of the bypass circuit. Since the control means is provided, when a new indoor unit is replaced, the liquid pipe and the gas pipe can be cleaned through the bypass circuit, and the cleaning efficiency is improved.
[0070]
Since the refrigeration / air conditioning apparatus according to claim 4 of the present invention uses a rotary valve as the flow rate control means in the refrigeration / air conditioning apparatus according to claim 3, the flow rate can be controlled with a simple configuration. Moreover, the reliability of cleaning can be improved by eliminating the caecum piping part that can be made into a branch pipe and preventing the refrigerating machine oil deteriorated during the cleaning from staying in the caecum piping part.
[0072]
The refrigeration / air-conditioning apparatus according to claim 5 of the present invention is the refrigeration / air-conditioning apparatus according to claim 1, wherein one liquid or gas-liquid two-phase refrigerant is provided in each branch pipe that is a connection pipe of the load-side heat exchanger. When a flow is sequentially washed, a small amount of refrigerant flows through the branch pipes of the other load-side heat exchangers. Therefore, of the liquid pipes and gas pipes connected to the load-side heat exchanger, the branches that are not washed It is possible to prevent the refrigerant from flowing back to the pipe and reattaching the deteriorated refrigeration oil to the cleaned pipe.
[0073]
The refrigeration / air conditioning apparatus according to claim 6 of the present invention is the refrigeration / air conditioning apparatus according to any one of claims 1 to 4, comprising a plurality of load-side heat exchangers, wherein the load-side heat exchange is performed. Since the branch pipes, which are connecting pipes of the vessel, are divided into groups and washed with a liquid or gas-liquid two-phase refrigerant, the washing time can be shortened.
[0074]
The refrigeration / air-conditioning apparatus according to claim 7 of the present invention is the refrigeration / air-conditioning apparatus according to claim 6, wherein the refrigeration / air-conditioning apparatus is grouped so that the sum of the pipe cross-sectional areas of the branch pipes to be cleaned is substantially equal. Since it is possible to flow a constant refrigerant flow rate to the pipe every time, it is possible to improve the reliability of cleaning.
[0075]
The refrigeration / air-conditioning apparatus according to claim 8 of the present invention is the refrigeration / air-conditioning apparatus according to claim 6, wherein the refrigeration / air-conditioning apparatus is grouped so that the sum of the capacities of the load-side heat exchangers is substantially equal. Even when a gas pipe is buried in a building, or when there is no piping construction drawing and the cross-sectional area of the pipe is not directly known, a constant coolant flow rate can be flowed into the pipe for each group, thus improving the cleaning reliability. it can.
[0076]
The refrigeration / air-conditioning apparatus according to claim 9 of the present invention is the refrigeration / air-conditioning apparatus according to any one of claims 6 to 8, wherein the opening degree of the flow control means is set to the capacity of each load-side heat exchanger. Accordingly, the unbalance of the flow rate of the refrigerant distributed to each branch pipe in the group can be reduced, and the cleaning reliability can be improved.
[0077]
The refrigeration / air-conditioning apparatus according to claim 10 of the present invention is the refrigeration / air-conditioning apparatus according to any one of claims 6 to 8, wherein the opening of the flow rate control means is connected to the connection pipe of the load-side heat exchanger. A fixed opening with a pressure loss greater than the pressure loss generated in the branch pipe, or by providing such a fixed throttle, the flow rate of refrigerant distributed to each branch pipe in the group is unbalanced. The reliability of cleaning can be increased.
[0078]
The refrigeration / air-conditioning apparatus according to claim 11 of the present invention is the refrigeration / air-conditioning apparatus according to any one of claims 6 to 8, wherein the pressure upstream of the flow rate control means, the downstream pressure and the flow rate control means. The flow rate of the refrigerant is calculated from the opening degree of the flow rate and the opening degree of the flow rate control means is corrected, so that the flow rate imbalance within each group is corrected with high accuracy and the control range for pipe length / height difference is widened. Reliability can be further increased.
[0081]
The refrigeration / air conditioning apparatus according to claim 12 of the present invention is the refrigeration / air conditioning apparatus according to any one of claims 1 to 9, wherein the flow direction of the refrigerant is reversed during the cleaning of the liquid pipe and the gas pipe. As a result, the amount of oil accumulated in the refrigerant distributor and the like connected to the plurality of load-side heat exchangers can be reduced.
[0082]
The refrigeration / air-conditioning apparatus according to claim 13 of the present invention is the refrigeration / air-conditioning apparatus according to any one of claims 1 to 12, in which oil that is compatible with the refrigerant to be washed is caused to flow in the middle of washing. Washing time can be shortened by mixing the deteriorated oil in the pipe with the oil and dissolving the mixed oil in a refrigerant and collecting it.
[0083]
The refrigeration / air-conditioning apparatus according to claim 14 of the present invention is the refrigeration / air-conditioning apparatus according to any one of claims 1 to 12, wherein in the course of cleaning, the refrigerant to be cleaned is incompatible or slightly compatible with viscosity remaining. Since oil lower than oil flows, the oil is prevented from being diluted by the refrigerant liquid, the oil is reliably mixed with the deteriorated oil in the existing piping, and the viscosity of the mixed oil is reduced. The moving speed can be increased and the cleaning time can be shortened.
[0084]
The refrigeration / air-conditioning apparatus according to claim 15 of the present invention is the refrigeration / air-conditioning apparatus according to claim 14, wherein the oil is used as a refrigerant gas when a compatible or incompatible oil is supplied to the refrigerant to be cleaned during the cleaning. Since the liquid or gas-liquid two-phase refrigerant flows after being circulated together, the oil and the refrigerating machine oil in the existing piping can be reliably mixed, and the cleaning time can be further shortened.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram of a refrigeration / air conditioning apparatus showing Embodiment 1 of the present invention.
FIG. 2 is a diagram showing the difference in the amount of residual oil in the piping with respect to the state of the refrigerant to be cleaned.
FIG. 3 is a control block diagram of the controller according to the first embodiment of the present invention.
FIG. 4 is a flowchart of general control according to the first embodiment of the present invention.
FIG. 5 is a control flowchart for preventing excessive temperature rise and liquid back according to the first embodiment of the present invention.
FIG. 6 is a refrigerant circuit diagram of another refrigeration / air-conditioning apparatus showing Embodiment 1 of the present invention.
FIG. 7 is a refrigerant circuit diagram of a refrigeration / air conditioning apparatus showing Embodiment 2 of the present invention.
FIG. 8 is a diagram showing a change in dryness in the refrigerant flow direction.
FIG. 9 is a diagram showing a pressure distribution in a refrigerant flow direction.
FIG. 10 is a refrigerant circuit diagram of another refrigeration / air-conditioning apparatus showing Embodiment 2 of the present invention.
FIG. 11 is a sectional view of a rotary valve according to a second embodiment of the present invention.
FIG. 12 is a diagram showing a change in the total flow path cross-sectional area and the refrigerant flow rate per unit cross-sectional area with respect to a change in the number of connected load-side heat exchangers according to the third embodiment of the present invention.
FIG. 13 is a diagram showing a refrigerant flow pattern in the vicinity of the connection between the main pipe and the branch pipe according to the third embodiment of the present invention.
FIG. 14 is a diagram showing the behavior of the refrigerant when the branch pipe on-off valve according to the third embodiment of the present invention is closed.
FIG. 15 is a diagram illustrating a change in the total flow passage cross-sectional area and the refrigerant flow rate per unit cross-sectional area with respect to a change in the number of connected load-side heat exchangers according to the fourth embodiment of the present invention.
FIG. 16 is a diagram illustrating a change in the diameter of a liquid pipe or a gas pipe connected to the load side heat exchanger with respect to a change in the capacity of the load side heat exchanger according to the fourth embodiment of the present invention.
FIG. 17 is a diagram showing a change in the required refrigerant flow rate and the opening degree of the flow control valve with respect to a change in the capacity of the load-side heat exchanger according to the fourth embodiment of the present invention.
FIG. 18 is a diagram showing the relationship between the pressure loss, the average refrigerant flow rate, and the minimum refrigerant flow rate of the flow control valve according to the fourth embodiment of the present invention.
FIG. 19 is a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to Embodiment 5 of the present invention.
FIG. 20 is a flowchart of control of a diaphragm device according to Embodiment 5 of the present invention.
FIG. 21 is a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to Embodiment 6 of the present invention.
FIG. 22 is a diagram showing a change in pressure in the refrigerant flow direction according to the sixth embodiment of the present invention.
FIG. 23 is a diagram showing a change in temperature in the refrigerant flow direction according to the sixth embodiment of the present invention.
FIG. 24 is a view for explaining cleaning of a pouch-like pipe according to a sixth embodiment of the present invention.
FIG. 25 is another diagram for explaining the cleaning of the pavement-like pipe according to the sixth embodiment of the present invention.
FIG. 26 is a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus, illustrating reverse cleaning according to Embodiment 6 of the present invention.
FIG. 27 is another refrigerant circuit diagram of the refrigeration / air-conditioning apparatus for explaining the reverse cleaning according to the sixth embodiment of the present invention.
FIG. 28 is a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to Embodiment 7 of the present invention.
FIG. 29 is a diagram showing a temporal change in the amount of residual oil when oil is supplied from an oil tank according to Embodiment 7 of the present invention and when oil is not supplied.
FIG. 30 is a refrigerant circuit diagram of a conventional refrigeration / air conditioning apparatus.
[Explanation of symbols]
1 compressor, 14 heat source side heat exchanger, 16 expansion device, 17 load side heat exchanger, 20 foreign matter recovery device, 22 refrigerant heat exchanger, 32 flow rate control means, 50 outdoor unit, 51 indoor unit, 101 liquid Pipe, 102 gas pipe,
107, 108 bypass circuit, 110 control means.

Claims (15)

圧縮機、熱源側熱交換器等により構成される室外機ユニットと、複数の負荷側熱交換器等により構成される室内機ユニットと、前記室内機ユニットもしくは前記室外機ユニットの少なくとも一方に設けた絞り装置と、前記室外機ユニットと前記室内機ユニットを接続する液管、ガス管と、を備え、前記液管及び前記ガス管、並びに前記室内機ユニットのうち少なくとも一方が第1の冷媒、冷凍機油で使用したものの再使用である冷凍・空調装置において、前記第１の冷媒、冷凍機油とは相違する第２の冷媒、冷凍機油を使用するに際して、制御手段により、前記第２の冷媒を液もしくは気液二相とし、該液もしくは気液二相の第２の冷媒で前記再使用部分を洗浄するとともに、前記複数の負荷側熱交換器の接続配管である枝管は、１本ずつ、液もしくは気液二相冷媒を順次流して洗浄することを特徴とする冷凍・空調装置。Provided in at least one of an outdoor unit composed of a compressor, a heat source side heat exchanger, etc., an indoor unit composed of a plurality of load side heat exchangers, etc., and the indoor unit or the outdoor unit A throttle device, and a liquid pipe and a gas pipe for connecting the outdoor unit and the indoor unit, and at least one of the liquid pipe, the gas pipe, and the indoor unit is a first refrigerant, a refrigeration In the refrigerating / air-conditioning apparatus that is reused for the machine oil used, when the second refrigerant and the refrigerating machine oil different from the first refrigerant and the refrigerating machine oil are used, the second refrigerant is liquefied by the control means. Alternatively, it is a gas-liquid two-phase, and the reuse part is washed with the liquid or the gas-liquid two-phase second refrigerant, and branch pipes that are connection pipes of the plurality of load-side heat exchangers, one by one, liquid Alternatively , a refrigeration / air-conditioning apparatus that is washed by sequentially flowing a gas-liquid two-phase refrigerant . 異物回収器と冷媒熱交換器を有する洗浄回路を備えたことを特徴とする請求項１記載の冷凍・空調装置。  The refrigeration / air-conditioning apparatus according to claim 1, further comprising a cleaning circuit having a foreign matter collector and a refrigerant heat exchanger. 負荷側熱交換器をバイパスするバイパス回路と、前記バイパス回路の冷媒流量を制御する流量制御手段を設けたことを特徴とする請求項１または請求項２記載の冷凍・空調装置。  The refrigeration / air conditioning apparatus according to claim 1 or 2, further comprising: a bypass circuit that bypasses the load-side heat exchanger; and a flow rate control unit that controls a refrigerant flow rate of the bypass circuit. 流量制御手段に、ロ−タリ−バルブを使用することを特徴とする請求項３記載の冷凍・空調装置。  4. The refrigeration / air conditioning apparatus according to claim 3, wherein a rotary valve is used as the flow rate control means. 枝管を、１本ずつ液もしくは気液二相冷媒を順次流して洗浄する場合、当該洗浄される枝管以外の枝管には小量の冷媒を流すことを特徴とする請求項１記載の冷凍・空調装置。 2. The branch pipe according to claim 1, wherein when the branch pipes are washed one by one by flowing liquid or gas-liquid two-phase refrigerant sequentially, a small amount of refrigerant is caused to flow through branch pipes other than the branch pipe to be washed. Refrigeration and air conditioning equipment. 圧縮機、熱源側熱交換器等により構成される室外機ユニットと、複数の負荷側熱交換器等により構成される室内機ユニットと、前記室内機ユニットもしくは前記室外機ユニットの少なくとも一方に設けた絞り装置と、前記室外機ユニットと前記室内機ユニットを接続する液管、ガス管と、を備え、前記液管及び前記ガス管、並びに前記室内機ユニットのうち少なくとも一方が第 1 の冷媒、冷凍機油で使用したものの再使用である冷凍・空調装置において、前記第１の冷媒、冷凍機油とは相違する第２の冷媒、冷凍機油を使用するに際して、制御手段により、前記第２の冷媒を液もしくは気液二相とし、該液もしくは気液二相の第２の冷媒で前記再使用部分を洗浄するとともに、前記負荷側熱交換器の接続配管である枝管は、これらの枝管をグル−プに分けて液もしくは気液二相冷媒で洗浄することを特徴とする冷凍・空調装置。 Provided in at least one of an outdoor unit composed of a compressor, a heat source side heat exchanger, etc., an indoor unit composed of a plurality of load side heat exchangers, etc., and the indoor unit or the outdoor unit A throttle device, and a liquid pipe and a gas pipe for connecting the outdoor unit and the indoor unit, and at least one of the liquid pipe, the gas pipe, and the indoor unit is a first refrigerant, a refrigeration In the refrigerating / air-conditioning apparatus that is reused for the machine oil used, when the second refrigerant and the refrigerating machine oil different from the first refrigerant and the refrigerating machine oil are used, the second refrigerant is liquefied by the control means. Alternatively, a gas-liquid two-phase system is used, and the reused portion is washed with the liquid or the gas-liquid two-phase second refrigerant, and the branch pipes that are connection pipes of the load-side heat exchanger are connected to the branch pipes. -A refrigeration / air-conditioning apparatus characterized by being washed with a liquid or a gas-liquid two-phase refrigerant separately . 洗浄する枝管の配管断面積の和がほぼ等しくなるようにグル−プ分けすることを特徴とする請求項６記載の冷凍・空調装置。 7. The refrigeration / air-conditioning apparatus according to claim 6, wherein the refrigeration / air-conditioning apparatus is grouped so that the sum of the cross-sectional areas of the branch pipes to be cleaned is substantially equal . 負荷側熱交換器の容量の和がほぼ等しくなるようにグル−プ分けすることを特徴とする請求項６記載の冷凍・空調装置。 7. The refrigeration / air conditioning apparatus according to claim 6, wherein the load-side heat exchangers are grouped so that the sum of the capacities of the load side heat exchangers is substantially equal . 流量制御手段の開度を各負荷側熱交換器の容量に応じた固定開度としたことを特徴とする請求項６乃至請求項８のいずれかに記載の冷凍・空調装置。 The refrigeration / air conditioning apparatus according to any one of claims 6 to 8, wherein the opening degree of the flow rate control means is a fixed opening degree corresponding to the capacity of each load-side heat exchanger . 流量制御手段の開度を負荷側熱交換器の接続配管である枝管で生じる圧力損失以上の圧力損失がつく固定開度とすること、または、そのような固定絞りを設けることを特徴とする請求項６乃至請求項８のいずれかに記載の冷凍・空調装置。 The opening degree of the flow rate control means is set to a fixed opening degree with a pressure loss equal to or higher than the pressure loss generated in the branch pipe which is a connecting pipe of the load side heat exchanger, or such a fixed throttle is provided. The refrigeration / air conditioning apparatus according to any one of claims 6 to 8 . 流量制御手段の上流及び下流の圧力と流量制御手段の開度とから冷媒流量を算出し、流量制御手段の開度を補正することを特徴とする請求項６乃至請求項８のいずれかに記載の冷凍・空調装置。 9. The refrigerant flow rate is calculated from pressures upstream and downstream of the flow rate control unit and the opening degree of the flow rate control unit, and the opening degree of the flow rate control unit is corrected. refrigeration and air-conditioning device. 液管およびガス管の洗浄途中において、冷媒の流れの向きを反転させることを特徴とする請求項１乃至請求項１１のいずれかに記載の冷凍・空調装置。 12. The refrigeration / air conditioning apparatus according to claim 1, wherein the flow direction of the refrigerant is reversed during the cleaning of the liquid pipe and the gas pipe . 洗浄途中において、洗浄する冷媒に相溶な油を流すことを特徴とする請求項１乃至請求項１２のいずれかに記載の冷凍・空調装置。 The refrigeration / air-conditioning apparatus according to any one of claims 1 to 12, wherein oil compatible with the refrigerant to be washed is caused to flow during washing . 洗浄途中において、洗浄する冷媒に非相溶もしくはわずかに相溶で、残留する油よりも粘度が低い油を流すことを特徴とする請求項１乃至請求項１２のいずれかに記載の冷凍・空調装置。 The refrigeration / air conditioning according to any one of claims 1 to 12, wherein an oil that is incompatible or slightly compatible with the refrigerant to be cleaned and having a viscosity lower than that of the remaining oil is allowed to flow during cleaning. apparatus. 洗浄途中において、洗浄する冷媒に相溶もしくは非相溶な油を流す時には、該油を冷媒ガスと共に循環させた後に、液もしくは気液二相冷媒を流すことを特徴とする請求項１３または請求項１４に記載の冷凍・空調装置。 The liquid or gas-liquid two-phase refrigerant is caused to flow after circulating the oil together with the refrigerant gas when flowing the compatible or incompatible oil to the refrigerant to be cleaned during the cleaning. Item 15. The refrigeration / air conditioning apparatus according to item 14 .
JP2000092852A 2000-03-30 2000-03-30 Refrigeration and air conditioning equipment Expired - Lifetime JP3799947B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000092852A JP3799947B2 (en) 2000-03-30 2000-03-30 Refrigeration and air conditioning equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000092852A JP3799947B2 (en) 2000-03-30 2000-03-30 Refrigeration and air conditioning equipment

Publications (2)

Publication Number Publication Date
JP2001280763A JP2001280763A (en) 2001-10-10
JP3799947B2 true JP3799947B2 (en) 2006-07-19

Family

ID=18608118

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2000092852A Expired - Lifetime JP3799947B2 (en) 2000-03-30 2000-03-30 Refrigeration and air conditioning equipment

Country Status (1)

Country Link
JP (1) JP3799947B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111023265A (en) * 2019-12-27 2020-04-17 宁波奥克斯电气股份有限公司 Self-cleaning control method and air conditioner

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4550635B2 (en) * 2005-03-17 2010-09-22 シャープ株式会社 Air conditioner
JP2008057941A (en) * 2006-09-04 2008-03-13 Fuji Electric Retail Systems Co Ltd Refrigerant cycle device
JP2008215697A (en) * 2007-03-02 2008-09-18 Mitsubishi Electric Corp Air conditioning device
JP4803234B2 (en) * 2008-09-29 2011-10-26 三菱電機株式会社 Pipe cleaning device
JP5197444B2 (en) * 2009-03-10 2013-05-15 三菱電機株式会社 Gas-liquid separator and refrigeration cycle equipment equipped with it
JP5014367B2 (en) * 2009-03-10 2012-08-29 三菱電機株式会社 Gas-liquid separator and refrigeration cycle equipment equipped with it
JP4902723B2 (en) * 2009-11-12 2012-03-21 三菱電機株式会社 Condensation pressure detection system and refrigeration cycle system
JP5063670B2 (en) * 2009-12-03 2012-10-31 三菱電機株式会社 AIR CONDITIONER AND METHOD OF CLEANING OPERATION OF AIR CONDITIONER
JP6391825B2 (en) * 2015-06-15 2018-09-19 三菱電機株式会社 Refrigeration cycle equipment

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111023265A (en) * 2019-12-27 2020-04-17 宁波奥克斯电气股份有限公司 Self-cleaning control method and air conditioner
CN111023265B (en) * 2019-12-27 2020-07-03 宁波奥克斯电气股份有限公司 Self-cleaning control method and air conditioner

Also Published As

Publication number Publication date
JP2001280763A (en) 2001-10-10

Similar Documents

Publication Publication Date Title
EP1970653B1 (en) Air conditioner
JP4120676B2 (en) Air conditioner
EP2017556A1 (en) Air conditioner
EP1970652A1 (en) Air conditioner
EP2048458B1 (en) Air conditioning apparatus
JP2008089292A (en) Air conditioner
JP3799947B2 (en) Refrigeration and air conditioning equipment
EP1970654B1 (en) Air conditioner
JP3840564B2 (en) Piping cleaning method and piping cleaning apparatus for refrigeration equipment
JP7005172B2 (en) Air conditioner
JP4289901B2 (en) Oil recovery method for air conditioner and air conditioner
JP2008025935A (en) Air conditioner
JP4665748B2 (en) Air conditioner
JP2005049057A (en) Refrigerating cycle device
JP4141339B2 (en) Air conditioner and refrigerating machine oil recovery method thereof
JP6715961B2 (en) Refrigeration cycle equipment
JP3255149B2 (en) Refrigerant flow path cleaning apparatus and refrigerant flow path cleaning method
JP5574638B2 (en) Refrigeration air conditioner
JP3494069B2 (en) Refrigerant recovery device and refrigerant recovery method
JP2001133087A (en) Piping-washing device and refrigerant-recovery device
JP2004308934A (en) Freezing apparatus and method of washing piping
JP2000304387A (en) Refrigerant circulating apparatus
JP2000297973A (en) Refrigerant recovering device
JP2001255044A (en) Piping cleaner and refrigerant regenerator

Legal Events

Date Code Title Description
RD01 Notification of change of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7421

Effective date: 20040629

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20050308

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20050428

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20060404

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20060417

R151 Written notification of patent or utility model registration

Ref document number: 3799947

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100512

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100512

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110512

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110512

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120512

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120512

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130512

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140512

Year of fee payment: 8

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

EXPY Cancellation because of completion of term