JP2004176967A

JP2004176967A - Refrigerating unit and defrosting method of refrigerating unit

Info

Publication number: JP2004176967A
Application number: JP2002342255A
Authority: JP
Inventors: Yoshiyasu Azuma; 義康東; Tokuo Takekoshi; 徳夫竹越
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2002-11-26
Filing date: 2002-11-26
Publication date: 2004-06-24
Anticipated expiration: 2022-11-26
Also published as: JP4131163B2

Abstract

<P>PROBLEM TO BE SOLVED: To relatively reduce the deterioration in temperature adjusting performance and useless consumption of energy. <P>SOLUTION: This refrigerating unit has two refrigerating circuits of first and second refrigerating circuits 11 and 12 in respective first to fourth outdoor units 1, 2, 3 and 4. This refrigerating unit is constituted so as to control defrosting operation with respective refrigerating circuits 11 and 12 by a control system. Thus, the second refrigerating circuit 12 of the first outdoor unit in close vicinity to a wall 8 and the second refrigerating circuit 22 of the second outdoor unit can be simultaneously operated for defrosting in spite of being different in the mutually belonging outdoor units. Since only the refrigerating circuits requiring the defrosting are simultaneously defrosted, the defrosting operation can be quickly performed, and useless consumption of the energy can be eliminated. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、冷凍装置および冷凍装置の除霜方法に関する。
【０００２】
【従来の技術】
従来、冷凍装置としては、冷媒配管に複数の室外ユニットを接続し、上記室外ユニットに１つの圧縮機と２つの熱交換器とを備え、この２つの熱交換器を上記冷媒配管に対して、並列および直列に切り換え可能に接続したものがある（例えば特許文献１参照）。上記冷媒配管に室内ユニットを接続し、この室内ユニットで室の暖房を行なう際、上記複数の室外ユニットのうちの１つの室外ユニットについて、除霜運転が必要になる場合がある。この場合、上記除霜運転すべき１つの室外ユニットが備える２つの熱交換器を、上記冷媒配管に対して並列に切り換え、上記冷媒配管を介して、上記他の室外ユニットから上記１つの室外ユニットに高温冷媒を供給して、この１つの室外ユニットの除霜運転を行なっている。
【０００３】
上記冷媒配管に複数の室外ユニットを接続した冷凍装置は、上記他の室外ユニットから上記１つの室外ユニットに高温冷媒を供給して除霜を行なうので、上記室内ユニットに供給する高温冷媒が大幅に減少して、暖房性能が大幅に低下するという問題がある。
【０００４】
そこで、従来、他の冷凍装置では、除霜運転をすべき室外ユニットのみによって、他の室外ユニットから冷媒の供給を受けないで除霜運転を行なっている。すなわち、上記他の冷凍装置は、水配管に複数の室外ユニットを接続し、この室外ユニットに、圧縮機と、第１熱交換器と、膨張器と、第２熱交換器とを有する冷凍回路を複数系統備える。上記複数の室外ユニットのうちの１つについて、この室外ユニットが備える複数系統の冷凍回路のうちの１つの冷凍回路の熱交換器が着霜した場合、この冷凍回路における冷媒の循環方向を逆転させる。これによって、上記着霜した熱交換器を凝縮器として働かせて、冷媒の凝縮熱によって除霜するようにしている。このとき、上記室外ユニットに設けられた上記複数の冷凍回路は、同一の室外ユニットに設けられて着霜条件が略同一であるから略同程度に着霜しているとして、全ての冷凍回路について、冷媒の循環方向を逆転して除霜運転を行なうようにしている。
【０００５】
【特許文献１】
特許第３１２３８７３号公報（第１図）
【０００６】
【発明が解決しようとする課題】
しかしながら、上記水配管に室外ユニットを接続した従来の冷凍装置は、上記除霜すべき熱交換器が属する室外ユニットについて、複数の冷凍回路の全てを除霜運転するので、この複数の冷凍回路のうちのいずれかが除霜が不用な熱交換器を含む場合であっても、この冷凍回路も除霜運転を行なうことになる。その結果、除霜時の温度調節性能の低下が比較的大きく、また、エネルギーの無駄な消費が比較的多いという問題がある。
【０００７】
そこで、本発明の目的は、除霜時の温度調節性能の低下が比較的少なく、エネルギーの無駄な消費が比較的少ない冷凍装置を提供することにある。
【０００８】
【課題を解決するための手段】
上記目的を達成するため、請求項１の発明の冷凍装置は、少なくとも圧縮機と、蒸発器と、膨張器と、凝縮器とを有する冷凍回路が複数系統設けられた室外ユニットを、水配管に複数個接続した冷凍装置において、
上記複数個の室外ユニットが備える全系統の冷凍回路について、冷凍回路毎に除霜運転を行なう制御装置を備えることを特徴としている。
【０００９】
請求項１の冷凍装置によれば、上記制御装置は、上記複数個の室外ユニットが備える全系統の冷凍回路について、冷凍回路毎に除霜運転を行なうので、除霜運転すべき冷凍回路のみが除霜運転される。したがって、従来におけるように、除霜運転すべき冷凍回路が属する室外ユニットに設けられた全ての冷凍回路を、除霜運転が不用な冷凍回路を含むにも拘らず除霜運転することが無いので、無駄な除霜運転が確実に回避される。その結果、除霜が必要な冷凍回路を除霜運転する間においても、除霜が不用な冷凍回路は通常の運転を継続することができるので、この冷凍装置の温度調節性能が安定にできる。したがって、この冷凍装置は、上記水配管を流れる水を安定して温度調節できる。その結果、上記水配管に例えば室内機を接続した場合、この室内機による暖房性能が安定にできる。また、この冷凍装置は、不用な除霜運転を削除できるので、エネルギーの無駄な消費が削減できる。
【００１０】
本発明において、１系統の冷凍回路とは、１つの圧縮機に、凝縮器と、膨張機構と、蒸発器とが接続されて冷媒の循環路を形成するものを言う。上記凝縮器および蒸発器は、同一ユニット内の他の系統の冷凍回路の凝縮器および蒸発器と一体に形成されていてもよい。
【００１１】
また、本発明において、１台の室外ユニットとは、フレーム等に複数の冷凍回路が搭載されて一体に形成されたものを言う。
【００１２】
従来、複数の冷凍回路を備える室外ユニットにおいて、上記複数の冷凍回路が各々有する熱交換器は、同一の室外ユニットに設けられているので、熱交換条件が互いに略同一であると想定されていた。したがって、上記複数の冷凍回路の熱交換器の１つについて、除霜運転が必要であると判断された場合、他の熱交換器についても除霜運転が必要であるとして、全ての冷凍回路について除霜運転を行なうようにしていた。しかしながら、室外ユニットが例えば建物の壁などに近接して配置されている場合、この壁に近い側の熱交換器は、上記壁から遠い側の熱交換器よりも、熱交換器を通過する空気の速度および量が少なくなる。したがって、上記壁に近い側の空気熱交換器は、上記壁から遠い側の熱交換器よりも熱交換量が少なくて温度が上昇し難くて、着霜し易い。この場合、上記壁に近い側の空気熱交換器への着霜に応じて除霜運転を行なうと、上記壁から遠い熱交換器は、除霜が不用であるにも拘らず除霜運転を行なうことになる。その結果、冷凍装置による水の温度調整性能の低下や、エネルギーの無駄な消費が増大していた。本発明者は、このような従来着目されていなかった課題を見出し、この課題を解決すべく本発明をなした。
【００１３】
請求項２の発明の冷凍装置は、請求項１に記載の冷凍装置において、
上記制御装置は、複数系統の冷凍回路について、同時に除霜運転を行なうことを特徴としている。
【００１４】
請求項２の冷凍装置によれば、上記制御装置は、上記複数系統の冷凍回路について、同時に除霜運転を行なうので、着霜した複数の熱交換器を迅速に除霜して、この冷凍装置による上記水配管の水の温度調整性能を迅速に回復できる。
【００１５】
請求項３の発明の冷凍装置は、請求項２に記載の冷凍装置において、
上記制御装置が同時に除霜運転を行なう複数系統の冷凍回路のうちの少なくとも１つの系統の冷凍回路は、他の系統の冷凍回路が属する室外ユニットと異なる室外ユニットに属することを特徴としている。
【００１６】
請求項３の冷凍装置によれば、上記制御装置が同時に除霜運転を行なう複数系統の冷凍回路のうちの少なくとも１つの系統の冷凍回路は、他の系統の冷凍回路が属する室外ユニットと異なる室外ユニットに属するので、除霜が必要な熱交換器のみを、迅速かつ良好な効率で除霜できる。
【００１７】
請求項４の発明の冷凍装置は、請求項２または３に記載の冷凍装置において、上記制御装置が同時に除霜運転を行なう冷凍回路の系統の数は、上記室外ユニットの個数に応じて予め定められた数以下であることを特徴としている。
【００１８】
請求項４の冷凍装置によれば、上記制御装置が同時に除霜運転を行なう冷凍回路の系統の数は、上記室外ユニットの個数に応じて予め定められた数以下であるので、この冷凍装置による上記水配管の水の温度調整性能が大幅に変化することが回避される。
【００１９】
請求項５の発明の冷凍装置の除霜方法は、少なくとも圧縮機と、蒸発器と、膨張器と、凝縮器とを有する冷凍回路が複数系統設けられた室外ユニットを、水配管に複数個接続し、
上記複数個の室外ユニットが備える全系統の冷凍回路のうち、複数系統の冷凍回路を同時に除霜運転を行ない、かつ、上記同時に除霜運転を行なう複数系統の冷凍回路のうちの少なくとも１つの系統の冷凍回路は、他の系統の冷凍回路が属する室外ユニットと異なる室外ユニットに属することを特徴としている。
【００２０】
請求項５の冷凍装置の除霜方法によれば、冷凍回路が複数系統設けられた室外ユニットが水配管に複数個接続され、この冷凍装置の全系統の冷凍回路のうち、属する室外ユニットが異なる複数系統の冷凍回路が同時に除霜運転されるので、除霜が必要な熱交換器を含む冷凍回路のみが除霜運転されるので、従来におけるように、除霜運転すべき冷凍回路と共に除霜運転が不用な冷凍回路が除霜運転されることが確実に回避できる。その結果、除霜運転時の冷凍装置の温度調節性能の低下や、エネルギーの無駄な消費が効果的に防止できる。
【００２１】
【発明の実施の形態】
以下、本発明を図示の実施の形態により詳細に説明する。
【００２２】
図１は、本実施形態の冷凍装置を示す図である。この冷凍装置は、第１，第２，第３，第４室外ユニット１，２，３，４の４つの室外ユニットを備える。この第１乃至第４室外ユニット１，２，…は、後述の水配管に並列に接続されている。
【００２３】
図２は、上記第１室外ユニット１が備える冷凍回路を示す図である。図２に示すように、この第１室外ユニット１は、圧縮機１１１と、水熱交換器１３と、膨張器１１４と、第１空気熱交換器１１５とが順に接続されてなる第１系統の冷凍回路１１を備える。上記圧縮機１１１と水熱交換器１３の間と、上記圧縮機１１１と第１空気熱交換器１１５の間とを、４路切り換え弁１１７で接続している。この４切り換え弁１１７を切り換えることによって、上記水熱交換器１３を凝縮器として働かせると共に上記第１空気熱交換器１１５を蒸発器として働かせる一方、上記水熱交換器１３を蒸発器として働かせると共に上記第１空気熱交換器１１５を凝縮器として働かせるように形成されている。上記第１空気熱交換器１１５には、温度センサ１１９を設けている。
【００２４】
また、この第１室外ユニット１は、圧縮機１２１と、上記水熱交換器１３と、膨張器１２４と、第２空気熱交換器１２５とが順に接続されてなる第２系統の冷凍回路１２を備える。上記圧縮機１２１と水熱交換器１３の間と、上記圧縮機１２１と第２空気熱交換器１２５の間とを、４路切り換え弁１２７で接続している。この４切り換え弁１２７を切り換えることによって、上記水熱交換器１３を凝縮器として働かせると共に上記第２空気熱交換器１２５を蒸発器として働かせる一方、上記水熱交換器１３を蒸発器として働かせると共に上記第２空気熱交換器１２５を凝縮器として働かせるように形成されている。上記第２空気熱交換器１２５には、温度センサ１２９を設けている。
【００２５】
上記第１室外ユニットの水熱交換器１３は、第１系統の冷凍回路１１と第２系統の冷凍回路１２とで共有されている。この水熱交換器１３には、水配管としての水供給管１５と水排出管１６が接続されている。上記水熱交換器１３は、上記水供給管１５から矢印Ｃで示すように供給される水と、冷媒とを熱交換させて、この熱交換されて昇温または降温した水を、矢印Ｄで示すように水排出管１６で排出するように形成されている。
【００２６】
上記第１冷凍回路１１および第２冷凍回路１２は、図示しないフレームに搭載されて一体に形成されて、第１室外ユニット１を構成している。
【００２７】
上記第２乃至第４室外ユニット２，３，４のいずれも、図２の第１室外ユニット１が備える冷凍回路と同一の冷凍回路を備える。すなわち、図１に示すように、上記第１乃至第４室外ユニット１，２，…のいずれも、第１系統の冷凍回路１１，２１，…と、第２系統の冷凍回路１２，２２，…との２つの系統の冷凍回路を各々備える。つまり、本実施形態の冷凍装置は、合計で８つの冷凍回路１１，１２，２１，２２，…を備える。なお、図１において、各冷凍回路１１，１２，２１，２２，…は、簡略化して矩形で示している。
【００２８】
また、上記第２乃至第４室外ユニット２，３，４のいずれも、図２の第１室外ユニット１が備える水供給管１５および水排出管１６と同一の水供給管および水排出管を備える。これら第１乃至第４室外ユニット１，２，…の水供給管１５，…および水排出管１６，…は、各々並列に接続されて、室内ユニットの熱交換器に接続されている。
【００２９】
上記第１乃至第４室外ユニット１，２，３，４は、建物の屋上に設置されている。上記第１乃至第４室外ユニット１，２，…は、上記屋上の壁８に近接して設置されている。より詳しくは、上記第１室外ユニット１と第２室外ユニット１，２の第２系統の冷凍回路１２，２２が、上記壁８に近接している。
【００３０】
上記第１室外ユニット１は、上記第１乃至第４室外ユニットの運転を制御する制御装置を備える。この制御装置は、各室外ユニットの第１空気熱交換器１１５，…および第２空気熱交換器１２５，…に取り付けた温度センサ１１９，１２９，…からの信号に基いて、上記室外ユニットの第１および第２系統の冷凍回路１１，１２，２１，２２，…を制御するようになっている。
【００３１】
上記構成の冷凍装置は、以下のように動作する。
【００３２】
上記冷凍装置の制御装置は、図示しない室内ユニットから、この室内ユニットに水配管を介して所定温度の水を送る指令を受けると、この室内ユニットからの指令に対応して、所定数の上記室外ユニットを起動する。この起動された各室外ユニットは、上記水配管の出口温度が所定温度になるように、上記各冷凍回路の圧縮機の容量等を調節する。
【００３３】
上記室内ユニットが室内を暖房する場合、上記制御装置は、例えば図２に示した第１室外ユニット１について、以下のような制御を行なう。
【００３４】
上記第１系統の冷凍回路において、上記４路切り換え弁１１７の弁方向を、上記水熱交換器１３が凝縮器として働くと共に上記第１空気熱交換器１１５が蒸発器として働く方向にする。そして、上記圧縮機１１１の運転を開始する。そうすると、この圧縮機１１１で圧縮された高温高圧の冷媒ガスが、上記水熱交換器１３に供給され、この水熱交換器１３で、上記水供給管１５からの水と熱交換して凝縮する。凝縮して低温高圧になった冷媒は、上記膨張器１１４によって膨張されて低圧になり、上記第１空気熱交換器１１５に導かれる。この第１空気熱交換器１１５に導かれた低温低圧の冷媒は、この第１空気熱交換器１１５に図示しないファンによって導かれる外気と熱交換して蒸発し、その後、上記圧縮機１１１に戻される。
【００３５】
また、上記第２系統の冷凍回路において、上記４路切り換え弁１２７の弁方向を、上記水熱交換器１３が凝縮器として働くと共に上記第２空気熱交換器１２５が蒸発器として働く方向にする。そして、上記圧縮機１２１の運転を開始する。そうすると、上記圧縮機１２１で圧縮された高温高圧の冷媒ガスが、上記水熱交換器１３に供給され、この水熱交換器１３で、上記水供給管１５からの水と熱交換して凝縮する。凝縮して低温高圧になった冷媒は、上記膨張器１２４を経て低圧になり、上記第２空気熱交換器１２５に導かれる。この第２空気熱交換器１２５に導かれた低温低圧の冷媒は、この第２空気熱交換器１２５に図示しないファンによって導かれる外気と熱交換して蒸発し、その後、上記圧縮機１１１に戻される。
【００３６】
上記水熱交換器１３において、上記第１および第２系統の冷凍回路の冷媒と熱交換して昇温した水は、上記水排出管１６に導かれて室内ユニットに戻る。この室内ユニットは、上記昇温した水を用いて、室内の暖房を行なう。
【００３７】
上記室内ユニットが行なうべき温度調節量に応じて、上記第１室外ユニット１と共に、第２乃至第４室外ユニットの少なくとも１つが適宜起動される。この第２乃至第４室外ユニットにおいても、図２の第１室外ユニット１と同様に、第１空気熱交換器および第２空気熱交換器によって外気から得た熱を、水配管で供給される水に、水熱交換器によって与える。こうして、上記室内ユニットに所定温度の水を供給する。
【００３８】
ここで、例えば第１室外ユニット１において、第１および第２冷凍回路１１，１２の運転が継続されるに連れて、上記第１空気熱交換器１１５および第２空気熱交換器１２５の外面に霜が付着する。この第１および第２空気熱交換器１１５，１２５の着霜量が過大になると、この第１および第２空気熱交換器１１５，１２５による熱交換効率が低下するので、上記着霜量が過大にならないうちに第１および第２空気熱交換器１１５，１２５の除霜を行なう必要がある。
【００３９】
図３は、本実施形態の冷凍装置で除霜運転が行なわれる際に、上記制御装置によって実行される処理を示すフロー図である。上記制御装置は、上記各室外ユニット１，２，…が備える全系統の冷凍回路毎について除霜の制御を行なう。
【００４０】
まず、冷凍装置が起動されて、起動すべき室外ユニットの第１および第２系統の冷凍回路について、圧縮機の運転が行なわれる（Ｓ１）。この圧縮機の運転が継続され、上記冷凍回路における冷媒の循環が継続されるに伴って、空気熱交換器の温度が降下する。上記制御装置は、各空気熱交換器の温度センサからの信号に基いて、各冷凍回路の空気熱交換器について、予め定められた除霜条件が成立するか否かを確認する（Ｓ２）。上記除霜条件が成立しないと判断すると、いずれの上記空気熱交換器も着霜していないとして、再びステップＳ２を繰り返して着霜条件の成否を確認する。
【００４１】
ステップＳ２において、所定の空気熱交換器が着霜したと判断すると、この着霜した空気熱交換器を含む冷凍回路の系統数が、除霜運転可能な系統数より少ないか否かを判断する（Ｓ３）。上記冷凍回路の除霜運転可能な系統数は、冷凍装置が備える室外ユニットの全台数に応じて予め定められた数である。表１は、上記室外ユニットの全台数に対応して、冷凍回路の全系統数と、この全系統数のうち、同時に除霜運転可能な系統数とを示した表である。
【００４２】
【表１】

【００４３】
表１に基いて、上記着霜した空気熱交換器を含む冷凍回路の系統数が、上記除霜運転可能な系統数よりも少ないと判断した場合、着霜した空気熱交換器を含む冷凍回路について、除霜運転を開始する（Ｓ４）。すなわち、上記着霜した空気熱交換器を含む冷凍回路について、４路切り換え弁を切り換えて冷媒の循環方向を逆転させると共に、圧縮機の容量を調節する。これによって、空気熱交換器を凝縮器として働かせると共に水熱交換器を蒸発器として働かせて、上記空気熱交換器の温度を上昇させて除霜を行なう。この除霜運転を、上記空気熱交換器に設けた温度センサが検出する温度が所定温度になるまで継続する（Ｓ５）。
【００４４】
上記制御装置は、上記温度センサからの信号に基いて、上記空気熱交換器の除霜が終了したことを検知すると、除霜運転を終了する（Ｓ６）。
【００４５】
この後、上記制御装置は、上記室内ユニットからの指令に基いて、上記水熱交換器からの水の温度調節を行なう通常の運転に戻る。
【００４６】
上記冷凍装置によれば、上記制御装置によって、上記４つの室外ユニット１，２，３，４が備える全系統の冷凍回路１１，１２，２１，２２…について、冷凍回路毎に除霜運転が行なわれるので、除霜運転すべき冷凍回路のみが除霜運転できる。
【００４７】
例えば、図１に示すように冷凍装置が奥条の壁８に近接して配置されている場合、第１室外ユニットと第２室外ユニットとに亘ってＡで示す部分が着霜し易い。すなわち、上記第１室外ユニットについて、上記壁８に近い側の第２系統の冷凍回路１２の空気熱交換器が、上記壁８に遠い側の第１系統の冷凍回路１１の空気熱交換器よりも着霜しやすい。また、上記第２室外ユニットについて、上記壁８に近い側の第２系統の冷凍回路２２の空気熱交換器が、上記壁８に遠い側の第１系統の冷凍回路２１の空気熱交換器よりも着霜しやすい。これは、上記壁８の存在によって、この壁８に近い側の空気熱交換器を通過する空気量が、上記壁８よりも遠い側の空気熱交換器を通過する空気量よりも少ないからである。
【００４８】
従来の冷凍装置では、室外ユニット毎に除霜運転を行なっていたので、図１に示すようなＡの部分に着霜が生じて、第１室外ユニットの第２系統の冷凍回路１２と、第２室外ユニットの第２系統の冷凍回路２２との除霜が必要になると、まず、第１室外ユニット１の第１および第２冷凍回路１１，１２を除霜運転していた。この後、第２室外ユニット２の第１および第２冷凍回路２１，２２を除霜運転していた。
【００４９】
これに対して、本実施形態の冷凍装置によれば、上記制御装置によって、上記第１室外ユニットの第２系統の冷凍回路１２と、上記第２室外ユニットの第２系統の冷凍回路２２とについて、同時に除霜運転を行なう。したがって、従来におけるように、第１室外ユニット１の除霜運転時に、除霜運転が不要な第１系統の冷凍回路１１までも除霜運転されることが回避される。また、第２室外ユニット２の除霜運転時に、除霜運転が不要な第１系統の冷凍回路２１までも除霜運転されることが回避される。その結果、エネルギーの無駄な消費が効果的に低減できる。また、除霜が不用な冷凍回路１１、２１は通常の運転が継続できるので、室内ユニットに送る水の温度調節性能が安定にできる。また、上記除霜運転が必要な冷凍回路１２，２２を同時に除霜運転するので、除霜運転に起因して冷凍装置の温度調節能力が低下する時間が、効果的に短くできる。これによって、上記水配管に接続された室内ユニットは、安定した暖房性能を得ることができる。
【００５０】
上記実施形態において、水配管１５，１６に４つの室外ユニット１，２，３，４を接続したが、２つ以上の幾つの室外ユニットを水配管に接続してもよい。
【００５１】
また、上記室外ユニットには、第１系統と第２系統との２つの系統の冷凍回路を設けたが、室外ユニットには２つ以上の幾つの冷凍回路を設けてもよい。この場合でも、制御装置によって冷凍回路毎に除霜運転が行なわれるので、各冷凍回路の着霜の程度に応じて、除霜が必要な冷凍回路のみを、適切な時期に除霜運転することができる。
【００５２】
【発明の効果】
以上より明らかなように、請求項１の発明の冷凍装置によれば、少なくとも圧縮機と、蒸発器と、膨張器と、凝縮器とを有する冷凍回路が複数系統設けられた室外ユニットを、水配管に複数個接続した冷凍装置において、上記複数個の室外ユニットが備える全系統の冷凍回路について、冷凍回路毎に除霜運転を行なう制御装置を備えるので、除霜運転すべき冷凍回路のみが除霜運転できて、無駄な除霜運転が確実に回避できる。したがって、エネルギーの無駄な消費が削減できる。また、除霜が不用な冷凍回路は通常の運転を継続することができるので、この冷凍装置の温度調節性能が安定にでき、その結果、上記水配管の水を安定して温度調節できる。
【００５３】
請求項２の発明の冷凍装置によれば、上記制御装置は、複数系統の冷凍回路について、同時に除霜運転を行なうので、着霜した複数の熱交換器を迅速に除霜して、この冷凍装置による上記水配管の水の温度調整性能を迅速に回復できる。
【００５４】
請求項３の発明の冷凍装置によれば、上記制御装置が同時に除霜運転を行なう複数系統の冷凍回路のうちの少なくとも１つの系統の冷凍回路は、他の系統の冷凍回路が属する室外ユニットと異なる室外ユニットに属するので、除霜が必要な熱交換器のみを、迅速かつ良好な効率で除霜できる。
【００５５】
請求項４の発明の冷凍装置によれば、上記制御装置が同時に除霜運転を行なう冷凍回路の系統の数は、上記室外ユニットの個数に応じて予め定められた数以下であるので、この冷凍装置による上記水配管の水の温度調整性能が大幅に変化することが防止できる。
【００５６】
請求項５の発明の冷凍装置の除霜方法によれば、少なくとも圧縮機と、蒸発器と、膨張器と、凝縮器とを有する冷凍回路が複数系統設けられた室外ユニットを、水配管に複数個接続し、上記複数個の室外ユニットが備える全系統の冷凍回路のうち、複数系統の冷凍回路を同時に除霜運転を行ない、かつ、上記同時に除霜運転を行なう複数系統の冷凍回路のうちの少なくとも１つの系統の冷凍回路は、他の系統の冷凍回路が属する室外ユニットと異なる室外ユニットに属するので、除霜が必要な熱交換器を含む冷凍回路のみが除霜運転できて、除霜運転時の冷凍装置の温度調節性能の低下や、エネルギーの無駄な消費が効果的に防止できる。
【図面の簡単な説明】
【図１】本発明の実施形態の冷凍装置を示す図である。
【図２】第１室外ユニットが備える冷凍回路を示す図である。
【図３】本実施形態の冷凍装置で除霜運転が行なわれる際に、制御装置によって実行される処理を示すフロー図である。
【符号の説明】
１第１室外ユニット
２第２室外ユニット
３第３室外ユニット
４第４室外ユニット
１１第１室外ユニットの第１系統の冷媒回路
１２第１室外ユニットの第２系統の冷媒回路
１３水熱交換器
２１第２室外ユニットの第１系統の冷媒回路
２２第２室外ユニットの第２系統の冷媒回路
３１第３室外ユニットの第１系統の冷媒回路
３２第３室外ユニットの第２系統の冷媒回路
４１第４室外ユニットの第１系統の冷媒回路
４２第４室外ユニットの第２系統の冷媒回路
１１１圧縮機
１１４膨張器
１１５第１空気熱交換器
１１７４路切り換え弁
１１９温度センサ
１２１圧縮機
１２４膨張器
１２５第２空気熱交換器
１２７４路切り換え弁
１２９温度センサ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a refrigeration apparatus and a method for defrosting the refrigeration apparatus.
[0002]
[Prior art]
Conventionally, as a refrigerating device, a plurality of outdoor units are connected to a refrigerant pipe, and the outdoor unit includes one compressor and two heat exchangers. The two heat exchangers are connected to the refrigerant pipe by: There is one that is switchably connected in parallel and in series (for example, see Patent Document 1). When an indoor unit is connected to the refrigerant pipe and the indoor unit is heated by the indoor unit, a defrosting operation may be required for one of the plurality of outdoor units. In this case, two heat exchangers provided in one outdoor unit to be subjected to the defrosting operation are switched in parallel to the refrigerant pipe, and the other outdoor unit is connected to the one outdoor unit via the refrigerant pipe. , A high-temperature refrigerant is supplied to this one outdoor unit to perform a defrosting operation.
[0003]
The refrigeration system in which a plurality of outdoor units are connected to the refrigerant pipe performs defrosting by supplying a high-temperature refrigerant from the other outdoor unit to the one outdoor unit, so that the high-temperature refrigerant supplied to the indoor unit is greatly reduced. Therefore, there is a problem that the heating performance is greatly reduced.
[0004]
Therefore, conventionally, in another refrigerating apparatus, the defrosting operation is performed only by the outdoor unit that should perform the defrosting operation without receiving the supply of the refrigerant from the other outdoor unit. That is, in the other refrigeration apparatus, a plurality of outdoor units are connected to a water pipe, and the outdoor unit has a refrigeration circuit including a compressor, a first heat exchanger, an expander, and a second heat exchanger. Are provided in multiple systems. For one of the plurality of outdoor units, when the heat exchanger of one of the refrigeration circuits of the plurality of refrigeration circuits provided in the outdoor unit is frosted, the circulation direction of the refrigerant in the refrigeration circuit is reversed. . Thus, the frosted heat exchanger is operated as a condenser, and defrost is performed by the heat of condensation of the refrigerant. At this time, the plurality of refrigeration circuits provided in the outdoor unit are provided in the same outdoor unit, and the frosting conditions are substantially the same, so that the frosting conditions are substantially the same, so that all the refrigeration circuits are assumed to be substantially the same. The defrosting operation is performed by reversing the circulation direction of the refrigerant.
[0005]
[Patent Document 1]
Japanese Patent No. 3123873 (FIG. 1)
[0006]
[Problems to be solved by the invention]
However, the conventional refrigeration apparatus in which an outdoor unit is connected to the water pipe performs the defrosting operation on all of the plurality of refrigeration circuits for the outdoor unit to which the heat exchanger to be defrosted belongs. Even if any of them includes a heat exchanger that does not require defrosting, this refrigeration circuit also performs defrosting operation. As a result, there is a problem that the temperature control performance at the time of defrosting is relatively reduced, and that wasteful consumption of energy is relatively large.
[0007]
Therefore, an object of the present invention is to provide a refrigeration apparatus in which the temperature control performance at the time of defrosting is relatively small and energy useless consumption is relatively small.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the refrigeration apparatus according to the first aspect of the present invention provides, in a water pipe, an outdoor unit provided with a plurality of refrigeration circuits including at least a compressor, an evaporator, an expander, and a condenser. In a refrigeration system with multiple connections,
The refrigeration circuit of the entire system included in the plurality of outdoor units includes a control device that performs a defrosting operation for each refrigeration circuit.
[0009]
According to the refrigeration apparatus of claim 1, the control device performs a defrosting operation for each refrigeration circuit for all refrigeration circuits provided in the plurality of outdoor units. Defrost operation is performed. Therefore, unlike the conventional case, all the refrigeration circuits provided in the outdoor unit to which the refrigeration circuit to be subjected to the defrosting operation belongs do not perform the defrosting operation even though the defrosting operation includes the unnecessary refrigeration circuit. In addition, useless defrosting operation is reliably avoided. As a result, even during the defrosting operation of the refrigeration circuit that requires defrosting, the refrigeration circuit that does not require defrosting can continue normal operation, so that the temperature control performance of the refrigeration apparatus can be stabilized. Therefore, this refrigeration apparatus can stably adjust the temperature of the water flowing through the water pipe. As a result, when, for example, an indoor unit is connected to the water pipe, the heating performance of the indoor unit can be stabilized. In addition, the refrigeration apparatus can eliminate unnecessary defrosting operation, thereby reducing wasteful consumption of energy.
[0010]
In the present invention, one system of refrigeration circuit refers to one in which a condenser, an expansion mechanism, and an evaporator are connected to one compressor to form a refrigerant circulation path. The condenser and the evaporator may be formed integrally with the condenser and the evaporator of another refrigeration circuit in the same unit.
[0011]
Further, in the present invention, one outdoor unit refers to one in which a plurality of refrigeration circuits are mounted on a frame or the like and are integrally formed.
[0012]
Conventionally, in an outdoor unit including a plurality of refrigeration circuits, since the heat exchangers of the plurality of refrigeration circuits are provided in the same outdoor unit, it has been assumed that the heat exchange conditions are substantially the same. . Therefore, when it is determined that the defrosting operation is necessary for one of the heat exchangers of the plurality of refrigeration circuits, it is determined that the defrosting operation is necessary for the other heat exchangers, and that all the refrigeration circuits are required. Defrosting operation was performed. However, when the outdoor unit is arranged close to, for example, a wall of a building, the heat exchanger on the side closer to the wall has more air passing through the heat exchanger than the heat exchanger on the side farther from the wall. Speed and quantity are reduced. Therefore, the air heat exchanger on the side closer to the wall has a smaller amount of heat exchange than the heat exchanger on the side farther from the wall, is less likely to rise in temperature, and is liable to frost. In this case, when the defrosting operation is performed according to the frost on the air heat exchanger on the side closer to the wall, the heat exchanger far from the wall performs the defrosting operation despite the fact that defrosting is unnecessary. Will do it. As a result, the temperature control performance of the water by the refrigeration system has been reduced, and wasteful energy consumption has been increased. The present inventor has found such a problem that has not been noticed in the past, and has made the present invention to solve the problem.
[0013]
A refrigeration apparatus according to a second aspect of the present invention is the refrigeration apparatus according to the first aspect,
The control device is characterized in that the defrosting operation is performed simultaneously on a plurality of refrigeration circuits.
[0014]
According to the refrigeration apparatus of claim 2, the control device performs the defrosting operation on the plurality of refrigeration circuits at the same time, so that the plurality of frosted heat exchangers are quickly defrosted. Thus, the water temperature adjustment performance of the water pipe can be quickly recovered.
[0015]
A refrigeration apparatus according to a third aspect of the present invention is the refrigeration apparatus according to the second aspect,
The refrigeration circuit of at least one of the plurality of refrigeration circuits in which the control device performs the defrosting operation at the same time belongs to an outdoor unit different from the outdoor unit to which the refrigeration circuits of the other systems belong.
[0016]
According to the refrigeration apparatus of claim 3, the refrigeration circuit of at least one of the plurality of refrigeration circuits in which the control device performs the defrosting operation at the same time is different from the outdoor unit to which the refrigeration circuits of the other systems belong. Since it belongs to the unit, only the heat exchanger that needs defrosting can be quickly and efficiently defrosted.
[0017]
According to a fourth aspect of the present invention, in the refrigeration apparatus according to the second or third aspect, the number of systems of the refrigeration circuit in which the control device performs the defrosting operation simultaneously is predetermined according to the number of the outdoor units. It is characterized by being less than the number given.
[0018]
According to the refrigerating apparatus of claim 4, the number of systems of the refrigerating circuit in which the control device performs the defrosting operation at the same time is equal to or less than a predetermined number according to the number of the outdoor units. A large change in the temperature control performance of the water in the water pipe is avoided.
[0019]
According to a fifth aspect of the present invention, there is provided a defrosting method for a refrigeration apparatus, wherein a plurality of outdoor units provided with a plurality of refrigeration circuits having at least a compressor, an evaporator, an expander, and a condenser are connected to a water pipe. And
Of the refrigeration circuits of all the systems provided by the plurality of outdoor units, the plurality of refrigeration circuits simultaneously perform the defrosting operation, and at least one of the plurality of refrigeration circuits simultaneously performing the defrosting operation. Is characterized by belonging to an outdoor unit different from the outdoor unit to which a refrigeration circuit of another system belongs.
[0020]
According to the method of defrosting a refrigeration system of claim 5, a plurality of outdoor units provided with a plurality of refrigeration circuits are connected to a water pipe, and the outdoor units to which the refrigeration circuits of all the refrigeration systems belong are different. Since the refrigeration circuits of a plurality of systems are simultaneously defrosted, only the refrigeration circuit including the heat exchanger that needs defrosting is defrosted. The defrosting operation of a refrigeration circuit that does not require operation can be reliably avoided. As a result, it is possible to effectively prevent the temperature control performance of the refrigeration apparatus from deteriorating during the defrosting operation and wasteful consumption of energy.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.
[0022]
FIG. 1 is a diagram showing a refrigeration apparatus of the present embodiment. This refrigerating apparatus includes four outdoor units, namely, first, second, third, and fourth

outdoor units

1, 2, 3, and 4. The first to fourth

outdoor units

1, 2, ... are connected in parallel to a water pipe described later.
[0023]
FIG. 2 is a diagram illustrating a refrigeration circuit included in the first outdoor unit 1. As shown in FIG. 2, the first outdoor unit 1 has a first system in which a compressor 111, a water heat exchanger 13, an expander 114, and a first air heat exchanger 115 are sequentially connected. A refrigeration circuit 11 is provided. The four-way switching valve 117 connects between the compressor 111 and the water heat exchanger 13 and between the compressor 111 and the first air heat exchanger 115. By switching the four-way switching valve 117, the water heat exchanger 13 works as a condenser and the first air heat exchanger 115 works as an evaporator, while the water heat exchanger 13 works as an evaporator. The first air heat exchanger 115 is formed to operate as a condenser. The first air heat exchanger 115 is provided with a temperature sensor 119.
[0024]
Further, the first outdoor unit 1 includes a second-system refrigeration circuit 12 in which a compressor 121, the water heat exchanger 13, the expander 124, and the second air heat exchanger 125 are sequentially connected. Prepare. The four-way switching valve 127 connects between the compressor 121 and the water heat exchanger 13 and between the compressor 121 and the second air heat exchanger 125. By switching the four-way switching valve 127, the water heat exchanger 13 works as a condenser and the second air heat exchanger 125 works as an evaporator, while the water heat exchanger 13 works as an evaporator. The second air heat exchanger 125 is configured to act as a condenser. The second air heat exchanger 125 is provided with a temperature sensor 129.
[0025]
The water heat exchanger 13 of the first outdoor unit is shared by the first system refrigeration circuit 11 and the second system refrigeration circuit 12. The water heat exchanger 13 is connected with a water supply pipe 15 and a water discharge pipe 16 as water pipes. The water heat exchanger 13 exchanges heat between the water supplied from the water supply pipe 15 as shown by the arrow C and the refrigerant, and the heat-exchanged water whose temperature has been increased or decreased is indicated by the arrow D. As shown, it is formed to be discharged by a water discharge pipe 16.
[0026]
The first refrigeration circuit 11 and the second refrigeration circuit 12 are mounted on a frame (not shown) and are integrally formed to constitute the first outdoor unit 1.
[0027]
Each of the second to fourth

outdoor units

2, 3, and 4 includes the same refrigeration circuit as the refrigeration circuit included in the first outdoor unit 1 in FIG. That is, as shown in FIG. 1, each of the first to fourth

outdoor units

1, 2,... Has a first refrigeration circuit 11, 21,. And two systems of refrigeration circuits. That is, the refrigeration apparatus of the present embodiment includes a total of eight

refrigeration circuits

11, 12, 21, 22,. In FIG. 1, each of the

refrigeration circuits

11, 12, 21, 22,... Is represented by a simplified rectangle.
[0028]
Further, each of the second to fourth

outdoor units

2, 3, and 4 has the same water supply pipe and water discharge pipe as the water supply pipe 15 and the water discharge pipe 16 provided in the first outdoor unit 1 of FIG. . The water supply pipes 15,... And the water discharge pipes 16,... Of the first to fourth

outdoor units

1, 2,... Are respectively connected in parallel and connected to the heat exchanger of the indoor unit.
[0029]
The first to fourth

outdoor units

1, 2, 3, and 4 are installed on the roof of a building. The first to fourth

outdoor units

1, 2,... Are installed close to the rooftop wall 8. More specifically, the

second refrigeration circuits

12 and 22 of the first outdoor unit 1 and the second

outdoor units

1 and 2 are close to the wall 8.
[0030]
The first outdoor unit 1 includes a control device that controls the operation of the first to fourth outdoor units. This control device is based on signals from the

temperature sensors

119, 129,... Attached to the first air heat exchangers 115,... And the second air heat exchangers 125,. The first and

second refrigeration circuits

11, 12, 21, 22,... Are controlled.
[0031]
The refrigerating apparatus having the above configuration operates as follows.
[0032]
Upon receiving a command to send water of a predetermined temperature to the indoor unit via a water pipe from an indoor unit (not shown), the control device of the refrigeration apparatus responds to the command from the indoor unit and outputs a predetermined number of the outdoor units. Start the unit. Each of the activated outdoor units adjusts the capacity and the like of the compressor of each of the refrigeration circuits so that the outlet temperature of the water pipe becomes a predetermined temperature.
[0033]
When the indoor unit heats the room, the control device performs the following control on the first outdoor unit 1 shown in FIG. 2, for example.
[0034]
In the refrigeration circuit of the first system, the valve direction of the four-way switching valve 117 is set so that the water heat exchanger 13 functions as a condenser and the first air heat exchanger 115 functions as an evaporator. Then, the operation of the compressor 111 is started. Then, the high-temperature and high-pressure refrigerant gas compressed by the compressor 111 is supplied to the water heat exchanger 13, where the refrigerant exchanges heat with water from the water supply pipe 15 and condenses. . The refrigerant that has been condensed to have a low temperature and a high pressure is expanded to a low pressure by the expander 114 and guided to the first air heat exchanger 115. The low-temperature and low-pressure refrigerant guided to the first air heat exchanger 115 exchanges heat with the outside air guided by a fan (not shown) to the first air heat exchanger 115 to evaporate, and then returns to the compressor 111. It is.
[0035]
Further, in the refrigeration circuit of the second system, the valve direction of the four-way switching valve 127 is set so that the water heat exchanger 13 functions as a condenser and the second air heat exchanger 125 functions as an evaporator. . Then, the operation of the compressor 121 is started. Then, the high-temperature and high-pressure refrigerant gas compressed by the compressor 121 is supplied to the water heat exchanger 13, where the refrigerant exchanges heat with water from the water supply pipe 15 and condenses. . The refrigerant that has been condensed to have a low temperature and a high pressure becomes a low pressure through the expander 124 and is guided to the second air heat exchanger 125. The low-temperature and low-pressure refrigerant guided to the second air heat exchanger 125 exchanges heat with the outside air guided by a fan (not shown) to the second air heat exchanger 125 to evaporate, and then returns to the compressor 111. It is.
[0036]
In the water heat exchanger 13, the water that has been heated by exchanging heat with the refrigerant in the first and second refrigeration circuits is guided to the water discharge pipe 16 and returns to the indoor unit. This indoor unit heats the room using the heated water.
[0037]
At least one of the second to fourth outdoor units is activated together with the first outdoor unit 1 according to the temperature adjustment amount to be performed by the indoor unit. Also in the second to fourth outdoor units, similarly to the first outdoor unit 1 in FIG. 2, heat obtained from the outside air by the first air heat exchanger and the second air heat exchanger is supplied by a water pipe. The water is fed by a water heat exchanger. Thus, water of a predetermined temperature is supplied to the indoor unit.
[0038]
Here, for example, in the first outdoor unit 1, as the operation of the first and second refrigeration circuits 11 and 12 is continued, the outer surfaces of the first air heat exchanger 115 and the second air heat exchanger 125 Frost adheres. If the amount of frost formed by the first and second

air heat exchangers

115 and 125 becomes excessive, the heat exchange efficiency of the first and second

air heat exchangers

115 and 125 decreases. It is necessary to perform defrosting of the first and second

air heat exchangers

115 and 125 before the temperature changes.
[0039]
FIG. 3 is a flowchart showing a process executed by the control device when a defrosting operation is performed in the refrigeration apparatus of the present embodiment. The control device controls defrosting for each of the refrigeration circuits of all the systems included in the

outdoor units

1, 2,....
[0040]
First, the refrigerating apparatus is started, and the compressor is operated for the first and second refrigerating circuits of the outdoor unit to be started (S1). As the operation of the compressor is continued and the circulation of the refrigerant in the refrigeration circuit is continued, the temperature of the air heat exchanger falls. The control device checks whether or not a predetermined defrosting condition is satisfied for the air heat exchanger of each refrigeration circuit based on a signal from the temperature sensor of each air heat exchanger (S2). If it is determined that the defrosting condition is not satisfied, it is determined that none of the air heat exchangers is frosted, and step S2 is repeated again to confirm whether the frosting condition is satisfied.
[0041]
When it is determined in step S2 that the predetermined air heat exchanger has formed frost, it is determined whether the number of systems of the refrigeration circuit including the frosted air heat exchanger is smaller than the number of systems capable of defrosting operation. (S3). The number of systems capable of performing the defrosting operation of the refrigeration circuit is a number determined in advance according to the total number of outdoor units provided in the refrigeration apparatus. Table 1 is a table showing the total number of refrigeration circuits and the number of systems that can be simultaneously defrosted among the total number of refrigeration circuits, corresponding to the total number of the outdoor units.
[0042]
[Table 1]

[0043]
Based on Table 1, when it is determined that the number of systems of the refrigeration circuit including the frosted air heat exchanger is smaller than the number of systems capable of the defrosting operation, the refrigeration circuit including the frosted air heat exchanger , A defrosting operation is started (S4). That is, in the refrigeration circuit including the frosted air heat exchanger, the four-way switching valve is switched to reverse the refrigerant circulation direction and adjust the capacity of the compressor. This allows the air heat exchanger to function as a condenser and the water heat exchanger to function as an evaporator, thereby increasing the temperature of the air heat exchanger and performing defrosting. This defrosting operation is continued until the temperature detected by the temperature sensor provided in the air heat exchanger reaches a predetermined temperature (S5).
[0044]
When the controller detects that the defrost of the air heat exchanger has been completed based on the signal from the temperature sensor, the controller ends the defrost operation (S6).
[0045]
Thereafter, the control device returns to the normal operation of adjusting the temperature of the water from the water heat exchanger based on a command from the indoor unit.
[0046]
According to the refrigerating apparatus, the defrosting operation is performed for each refrigerating circuit of the refrigerating

circuits

11, 12, 21, 22,... Of all the systems provided in the four

outdoor units

1, 2, 3, 4 by the control device. Therefore, only the refrigeration circuit that should perform the defrost operation can perform the defrost operation.
[0047]
For example, as shown in FIG. 1, when the refrigeration apparatus is disposed close to the inner wall 8, the portion indicated by A over the first outdoor unit and the second outdoor unit is easily frosted. That is, for the first outdoor unit, the air heat exchanger of the second refrigeration circuit 12 closer to the wall 8 is more than the air heat exchanger of the first refrigeration circuit 11 farther from the wall 8. Also easy to frost. Further, in the second outdoor unit, the air heat exchanger of the second refrigeration circuit 22 on the side closer to the wall 8 is different from the air heat exchanger of the first refrigeration circuit 21 on the side farther from the wall 8. Also easy to frost. This is because, due to the presence of the wall 8, the amount of air passing through the air heat exchanger near the wall 8 is smaller than the amount of air passing through the air heat exchanger farther than the wall 8. is there.
[0048]
In the conventional refrigeration apparatus, since the defrosting operation is performed for each outdoor unit, frost is formed on the portion A as shown in FIG. 1 and the second refrigeration circuit 12 of the first outdoor unit and the second refrigeration circuit 12 When defrosting of the two outdoor units with the second-system refrigeration circuit 22 is required, first, the first and second refrigeration circuits 11 and 12 of the first outdoor unit 1 are operated for defrosting. Thereafter, the first and

second refrigeration circuits

21 and 22 of the second outdoor unit 2 were operated for defrosting.
[0049]
On the other hand, according to the refrigeration apparatus of the present embodiment, the control device controls the refrigeration circuit 12 of the second system of the first outdoor unit and the refrigeration circuit 22 of the second system of the second outdoor unit. At the same time, a defrosting operation is performed. Therefore, it is possible to prevent the defrosting operation of the first refrigeration circuit 11 that does not require the defrosting operation during the defrosting operation of the first outdoor unit 1 as in the related art. Further, at the time of the defrosting operation of the second outdoor unit 2, the defrosting operation of even the first-system refrigeration circuit 21 that does not require the defrosting operation is avoided. As a result, wasteful consumption of energy can be effectively reduced. In addition, since the refrigeration circuits 11 and 21 that do not require defrosting can continue normal operation, the temperature control performance of the water sent to the indoor unit can be stabilized. In addition, since the

refrigeration circuits

12 and 22 that require the defrosting operation are simultaneously defrosted, the time during which the temperature control capability of the refrigeration apparatus is reduced due to the defrosting operation can be effectively shortened. Thereby, the indoor unit connected to the water pipe can obtain stable heating performance.
[0050]
In the above embodiment, the four

outdoor units

1, 2, 3, 4 are connected to the

water pipes

15, 16, but two or more outdoor units may be connected to the water pipes.
[0051]
Further, the outdoor unit has two refrigeration circuits, a first system and a second system, but the outdoor unit may have two or more refrigeration circuits. Even in this case, since the defrosting operation is performed for each refrigeration circuit by the control device, only the refrigeration circuit that needs defrosting at the appropriate time should be defrosted according to the degree of frost formation in each refrigeration circuit. Can be.
[0052]
【The invention's effect】
As is clear from the above, according to the refrigerating apparatus of the first aspect of the present invention, an outdoor unit provided with a plurality of refrigerating circuits each having at least a compressor, an evaporator, an expander, and a condenser is provided with a water supply system. In the refrigeration apparatus connected to a plurality of pipes, a control device for performing a defrost operation for each refrigeration circuit is provided for all refrigeration circuits provided in the plurality of outdoor units. Defrosting operation can be performed, and wasteful defrosting operation can be reliably avoided. Therefore, useless consumption of energy can be reduced. Further, since the refrigeration circuit that does not require defrosting can continue normal operation, the temperature control performance of the refrigeration apparatus can be stabilized, and as a result, the temperature of the water in the water pipe can be stably controlled.
[0053]
According to the refrigeration apparatus of the second aspect of the present invention, since the control device performs the defrosting operation simultaneously on a plurality of refrigeration circuits, it quickly defrosts the plurality of frosted heat exchangers, The water temperature adjustment performance of the water pipe by the device can be quickly restored.
[0054]
According to the refrigeration apparatus of the third aspect of the present invention, the refrigeration circuit of at least one of the plurality of refrigeration circuits in which the control device performs the defrosting operation at the same time is connected to the outdoor unit to which the refrigeration circuits of the other systems belong. Since it belongs to a different outdoor unit, only the heat exchanger that needs defrosting can be quickly and efficiently defrosted.
[0055]
According to the refrigerating apparatus of the fourth aspect, the number of systems of the refrigerating circuit in which the control device performs the defrosting operation at the same time is equal to or less than a predetermined number according to the number of the outdoor units. The water temperature adjustment performance of the water pipe by the device can be prevented from changing significantly.
[0056]
According to the method for defrosting a refrigerating apparatus of the invention of claim 5, a plurality of outdoor units provided with a plurality of refrigerating circuits having at least a compressor, an evaporator, an expander, and a condenser are provided in a water pipe. The refrigeration circuits of the plurality of outdoor units provided in the plurality of outdoor units are simultaneously connected to perform the defrosting operation of the plurality of refrigeration circuits, and the refrigeration circuits of the plurality of systems performing the defrosting operation simultaneously. Since the refrigeration circuit of at least one system belongs to an outdoor unit different from the outdoor unit to which the refrigeration circuit of the other system belongs, only the refrigeration circuit including the heat exchanger requiring defrost can perform the defrost operation, and the defrost operation can be performed. In this case, it is possible to effectively prevent the temperature control performance of the refrigeration apparatus from deteriorating and wasteful energy consumption.
[Brief description of the drawings]
FIG. 1 is a diagram showing a refrigeration apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a refrigeration circuit provided in a first outdoor unit.
FIG. 3 is a flowchart illustrating a process executed by a control device when a defrosting operation is performed in the refrigeration apparatus of the present embodiment.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 First outdoor unit 2 Second outdoor unit 3 Third outdoor unit 4 Fourth outdoor unit 11 First refrigerant circuit 12 of first outdoor unit Second refrigerant circuit 13 of first outdoor unit Water heat exchanger 21 The first system refrigerant circuit 22 of the second outdoor unit The second system refrigerant circuit 31 of the second outdoor unit The first system refrigerant circuit 32 of the third outdoor unit The second system refrigerant circuit 41 of the third outdoor unit 41 The fourth First-system refrigerant circuit of outdoor unit 42 Second-system refrigerant circuit of fourth outdoor unit 111 Compressor 114 Expander 115 First air heat exchanger 117 Four-way switching valve 119 Temperature sensor 121 Compressor 124 Expander 125 2 air heat exchanger 127 4-way switching valve 129 Temperature sensor

Claims

An outdoor in which a plurality of refrigeration circuits (11, 12) having at least compressors (111, 121), condensers (13), expanders (114, 124), and evaporators (115, 125) are provided. In a refrigerating apparatus in which a plurality of units (1, 2, 3, 4) are connected to water pipes (15, 16),
The defrosting operation is performed for each of the refrigeration circuits for the refrigeration circuits (11, 12, 21, 22, 31, 32, 41, 42) of the entire system included in the plurality of outdoor units (1, 2, 3, 4). A refrigeration apparatus comprising a control device.

The refrigeration apparatus according to claim 1,
The refrigerating apparatus is characterized in that the control device simultaneously performs a defrosting operation on a plurality of refrigerating circuits (11, 12, 21, 22, 31, 32, 41, 42).

The refrigeration apparatus according to claim 2,
At least one of the refrigeration circuits (11, 12, 21, 22, 22) of the plurality of refrigeration circuits (11, 12, 21, 22, 31, 32, 41, 42) in which the control device performs the defrosting operation at the same time. , 31, 32, 41, 42) are different from the outdoor units (1, 2, 3, 4) to which the refrigeration circuits (11, 12, 21, 22, 31, 32, 41, 42) of the other systems belong. A refrigeration apparatus, which belongs to the unit (1, 2, 3, 4).

The refrigeration apparatus according to claim 2 or 3,
The number of systems of the refrigeration circuits (11, 12, 21, 22, 31, 32, 41, 42) in which the control device simultaneously performs the defrosting operation is equal to the number of the outdoor units (1, 2, 3, 4). A refrigerating apparatus, wherein the number is equal to or less than a predetermined number.

A refrigeration circuit (11, 12, 21, 22, 31, 32) having at least a compressor (111, 121), a condenser (13), an expander (114, 124), and an evaporator (115, 125). , 41, 42) are connected to the water pipes (15, 16) by connecting a plurality of outdoor units (1, 2, 3, 4) provided with a plurality of systems,
Of the refrigeration circuits (11, 12, 21, 22, 31, 32, 41, 42) of the entire system provided in the plurality of outdoor units (1, 2, 3, 4), the refrigeration circuits (11, 12,21,22,31,32,41,42) and a plurality of refrigeration circuits (11,12,21,22,31,32,41) for performing the defrosting operation simultaneously. , 42), the refrigeration circuits (11, 12, 21, 22, 31, 32, 41, 42) of at least one system are refrigeration circuits (11, 12, 21, 22, 31, 31, 32) of another system. , 41, 42) belonging to an outdoor unit (1, 2, 3, 4) different from the outdoor unit (1, 2, 3, 4).