【０００１】
【発明の属する技術分野】
本発明は、室内機と室外機とを備えた空調装置に係り、特に相変化する二次冷媒を用いた吸収式冷温熱発生装置に関する。
【０００２】
【従来の技術】
従来の吸収式冷温熱発生装置においては、図３に示す構成の吸収冷温水機（室外機）を用いた空調装置が知られている。空調装置は、冷温熱を発生する吸収冷温水機１００と、この吸収冷温水機１００に冷却水管４０，４１で接続され冷却水を冷却するクーリングタワー４２と、冷却水管４１に介装され冷却水をクーリングタワー４２から吸収冷温水機１００に循環させる冷却水循環ポンプ１４と、吸収冷温水機１００に冷温水管４３，４４で接続され空調対象空間に配置されて空間の空気との熱交換を行う図示しない空調用室内機（室内機）と、冷温水管４３に介装され冷温水管４３，４４に充填された二次冷媒を吸収冷温水機１００と空調用室内機との間に循環させる冷温水循環ポンプ１５とを含んで構成されている。
【０００３】
空調用室内機に対して、クーリングタワー４２と併せて通常、室外機と呼ばれる吸収冷温水機１００は、燃料を燃焼させその熱で希溶液を加熱する高温再生器１と、この高温再生器１で加熱された希溶液から冷媒蒸気と中間濃溶液とを分離する分離器２と、分離された冷媒蒸気を熱源として中間濃溶液を加熱してさらに二次冷媒蒸気を発生させる低温再生器３と、低温再生器３を通過した冷媒蒸気及び低温再生器３で発生した二次冷媒蒸気を冷却して凝縮液化させ液冷媒を生成する凝縮器４と、凝縮器４で生成された液冷媒を内装した冷媒分配器６Ｂから同じく内装した蒸発コイル上に滴下蒸発させ蒸発コイル中の二次冷媒を冷却する蒸発器６と、蒸発器６で蒸発した冷媒蒸気を濃溶液に吸収させ希溶液を生成する吸収器５と、希溶液を加圧し低温溶液熱交換器８及び高温溶液熱交換器７の被加熱流体側を経て高温再生器１に送りこむ溶液循環ポンプ９と、分離器２の底部と蒸発器６の底部を冷暖切換弁１０を介して連通する管路１０Ａと、低温溶液熱交換器８の加熱流体出側を吸収器５の上部に接続する濃溶液管８Ａと、濃溶液管８Ａと吸収器５の下部を溶液バイパス弁１３を介して接続する管路１３Ａと、濃溶液管８Ａと蒸発器５に内装された冷媒分配器６Ｂを凍結防止弁１２を介して連通する管路１２Ａと、冷媒分配器６Ｂに装着され冷媒分配器６Ｂ内の冷媒の温度を検知する蒸発器温度センサ１７と、凝縮器４から冷媒分配器６Ｂに液冷媒を導く水冷媒管１１Ｂと、水冷媒管１１Ｂに並列に接続され水冷媒比例弁１１を介装する管路１１Ａとを含んで構成されている。
【０００４】
また、分離器２で分離された中間濃溶液が高温溶液熱交換器７の加熱流体側を経て低温再生器３に導かれ、低温再生器３で冷媒を蒸発させて濃溶液となったのち、低温溶液熱交換器８の加熱流体側を経て濃溶液管８Ａに導かれるように管路が構成されている。吸収器５及び凝縮器４にはそれぞれ冷却水コイルが内装され、吸収器５の冷却水コイルの出口は凝縮器４の冷却水コイルの入り口に接続されていて、吸収器５の冷却水コイルの入り口は冷却水管４１に、凝縮器４の冷却水コイルの出口は冷却水管４０に、それぞれ接続されている。冷温水管４３は蒸発器６の蒸発コイル６Ａの入り側に、冷温水管４４は蒸発器６の蒸発コイル６Ａの出側に、それぞれ接続され、冷温水管４４の蒸発コイル出口近傍には二次冷媒の温度を検知する冷水出口温度センサ１６が装着されている。
【０００５】
室内機と室外機との間で循環して熱を搬送する二次冷媒として、相変化をしない流体、一般に液体が用いられてきたが、近年、二次冷媒に相変化を行わせることにより、単位流量あたりの熱搬送量を増加させるものが開発されている。図４はそのような構成の例を示すもので、図３に示す構成のうち、冷温水管４３，４４に代えて冷媒液管５０及び冷媒ガス管５１が蒸発コイル６Ａの下端及び上端にそれぞれ接続されている。冷媒液管５０及び冷媒ガス管５１の他端は、蒸発コイル６Ａよりも下方に配置された複数の室内機５２，５３の数だけ分岐しており、冷媒液管５０の分岐端は、室内機５２，５３にそれぞれ内装された熱交換器の下側入り口に膨張弁５４，５５を介して接続され、冷媒ガス管５１の分岐端は、熱交換器の上側入り口にそれぞれ接続されている。冷媒液管５０と蒸発コイル６Ａとの接続部近傍には、二次冷媒の温度を検出して電気信号としてコントローラ５９に出力する冷媒液温度センサ２１が装着されている。
【０００６】
冷媒液管５０は、途中に室内機５２，５３よりも低位置に配置された部分（Ｕ字管）があり、そこに冷媒液を加圧して蒸発コイル６Ａに送りこむ冷媒ポンプ５７が装着されている。冷媒ポンプ５７の吐出側には、逆止弁５８が設けられ、この逆止弁５８の出側と冷媒ポンプ５７の吸い込み側とは、冷暖切換弁５６を介して接続されている。相変化する二次冷媒（以下単に冷媒ともいう）として、ＨＦＣ−１３４ａが冷媒液管に充填されている。他の構成は図３の説明と同じであるので、説明は省略する。
【０００７】
図４に示す空調装置の冷房時の動作は次の通りである。冷房時には、冷暖切換弁５６は開かれている。冷媒蒸気（ＨＦＣ−１３４ａ）は、蒸発器６の蒸発コイル６Ａで冷却凝縮されて冷媒液となり、重力により、冷媒液管５０を下方に流れ、膨張弁５４，５５を経て各室内機５２，５３の熱交換器に流入する。熱交換器に流入した冷媒液は、空調対象空間の空気の熱を奪って蒸発し、冷媒蒸気となって冷媒ガス管５１を経て上昇し蒸発器６の蒸発コイル６Ａに流入する。室外機１００は冷房モードで運転されているから、蒸発器６の蒸発コイル６Ａは、その表面に滴下される水冷媒の蒸発により冷却され、蒸発コイル６Ａに流入してきた冷媒蒸気（ＨＦＣ−１３４ａ）は、凝縮液化する。この凝縮液化により、蒸発コイル６Ａ内部の圧力が低下し、室内機５２，５３の熱交換器で蒸発した冷媒蒸気は蒸発器６に吸引される。蒸発コイル６Ａ内部で凝縮液化した冷媒液は重力で室内機５２，５３に流入するから、冷房時の冷媒（ＨＦＣ−１３４ａ）は、自然循環し、冷媒ポンプによる冷媒の駆動を行う必要がない。
【０００８】
冷房運転が開始されると、前記のように、蒸発コイル６Ａ内部の圧力が低下し、冷媒ガス管５１内の飽和冷媒蒸気が圧力差により蒸発コイル６Ａ内に流入する。蒸発コイル６Ａ内で凝縮して生成された冷媒液は、冷媒液管５０内を自重で流下し、冷媒液ヘッド（液柱）が上昇してくる。冷媒の自然循環が成立するためには、（冷媒液ヘッド）−（冷媒ガスヘッド）が冷媒循環経路の全圧力損失以上であればよい。つまり、次式を満足する液ヘッドが形成されるまでは冷媒の自然循環は開始されない。このことは、冷房運転開始時点で蒸発器６に供給される熱負荷が少ないことを意味する。
【０００９】
【数１】
【００１０】
暖房時には、冷暖切換弁５６は閉じられている。冷媒液（ＨＦＣ−１３４ａ）は、蒸発器６の蒸発コイル６Ａで加熱されて冷媒蒸気となり、冷媒ガス管５１を下方に流れ、各室内機５２，５３の熱交換器に流入する。熱交換器に流入した冷媒蒸気は、空調対象空間の空気に熱を奪われて凝縮液化し、冷媒液となって冷媒液管を下方に流れて冷媒ポンプ５７入り側に流入する。冷媒液は冷媒ポンプ５７で加圧され、蒸発器６の蒸発コイル６Ａに流入して前記のサイクルを繰り返す。このとき、室外機１００は暖房モードで運転され、蒸発器６には分離器２で分離された高温の溶液が導かれ、蒸発コイル６Ａはこの熱により加熱される。
【００１１】
ここで、冷房運転時にＨｉｇｈ−Ｌｏｗ−ＯＦＦの段階制御を行うと、冷媒ガス管内と冷媒液管内の圧力が変動する。Ｈｉｇｈ運転時は、冷媒ガス管内と冷媒液管内との圧力差もあり、飽和冷媒蒸気が冷媒液管内で滞留することはない。一方、Ｌｏｗ〜ＯＦＦ運転時は、過冷却となり、蒸発コイル内に冷媒液が溜り、蒸発コイルが液封された状態となり冷媒ガス管と冷媒液管との圧力差が少なくなるため、通常の冷媒液ヘッドがとれない。このため、自然循環させる駆動力が弱くなる。
【００１２】
また暖房時にはＨｉｇｈ（高負荷）−Ｌｏｗ（低負荷）−ＯＦＦ（停止）運転で蒸発コイル内の冷媒の液面高さが異なる。Ｌｏｗ運転時は、負荷が少なく室内機の運転台数が少ないと、冷房時に一番圧力の低い室外機の蒸発器コイル内に、室内機の冷媒保有量に相当する量の冷媒が溜ってきて、蒸発器内の液面が上昇する。（ただしそれでもＬｏｗ運転時の必要伝熱面積は確保されている。）そしてＯＦＦ運転では、さらに液面が上昇して冷媒ガス管に流入する恐れがあり、また冷媒液管内に冷媒ガスが混在していて液面が不安定になる恐れがある。そこで冷媒液管と冷媒ガス管との間に冷媒のバイパス管を設け、このバイパス管に二方弁である冷媒電磁弁を設ける。そして、冷媒電磁弁を暖房運転時の全てのモードで開し、かつ冷房運転時に全てのモードで閉し、冷媒液内の冷媒ガスをバイパス管を経て冷媒ガス管へ逃がし、かつ液面の変化を液面レベルスイッチで検出して冷媒ポンプの発停を行うことが考えられる。しかし、冷媒ポンプ側の液面レベルスイッチとともに冷媒ポンプのＯＮ−ＯＦＦ発停を２個所の液面レベルスイッチで制御することになり、頻繁な発停となって安定した運転ができない。システムとして安定した運転をするためには、暖房時に冷媒ポンプが連続して運転される方がよく、冷媒ポンプ保護のため、冷媒ポンプの上流側にレシーバーを設置して液面レベルを監視してキャビテーションのない運転制御が必須要件である。
【００１３】
【発明が解決しようとする課題】
上記のような吸収式冷温熱発生装置にあっては、冷房時のＨｉｇｈ運転では、冷媒ガス管内と冷媒液管内との圧力差があり、飽和冷媒蒸気が冷媒液管内で滞留することはない。一方、Ｌｏｗ〜ＯＦＦ運転時は、過冷却となり、蒸発コイル内に冷媒液が溜り、蒸発コイルが液封された状態となり、冷媒ガス管と冷媒液管との圧力差が少なくなるため、通常の冷媒液ヘッドがとれない。このため、自然循環させる駆動力が弱くなる問題がある。
【００１４】
また暖房時のＬｏｗ運転で蒸発器内の液面が上昇し、ＯＦＦ運転では、さらに上昇して冷媒液が冷媒ガス管に流入する。また冷媒液管内に冷媒ガスが混入していて液面が不安定になる問題がある。さらに暖房時に冷媒ポンプの発停を２個所の液面レベルスイッチで制御すると、頻繁な発停となって安定した運転ができない問題がある。
【００１５】
本発明の目的は、相変化する二次冷媒を用いて冷房時に自然循環させ、暖房時に冷媒ポンプを連続運転させることのできる吸収式冷温熱発生装置を提供することにある。
【００１６】
【課題を解決するための手段】
前記の目的を達成するため、本発明に係る吸収式冷温熱発生装置は、再生器、凝縮器、吸収器及び蒸発器を含む室外機と、蒸発器内の蒸発コイルの下端と下降管及びＵ字管を経由して少なくとも一つの室内機に接続された二次冷媒の冷媒液管と、冷媒液管のＵ字管に配置された冷媒ポンプと、蒸発コイルの上端とそれぞれの室内機とに接続された冷媒ガス管とを備えた吸収式冷温熱発生装置において、冷媒ポンプとそれぞれの室内機との間の冷媒液管に液位レベルスイッチを設け、冷媒ガス管に蒸発コイルの上端より突出する立上り管を形成し、立上り管と冷媒液管との間にバイパス管を接続し、バイパス管に立上り管へ近接させて冷媒電磁弁を配置し、暖房時に、冷媒電磁弁を全開に制御するとともに、冷媒液量の低下による液位レベルスイッチの作動又は室外機の燃焼停止で冷媒ポンプを停止し、冷房時に、冷媒電磁弁を高負荷運転で全閉し、かつ低負荷運転又は停止運転で全開にする制御手段を備えた構成とする。
【００１７】
そして室外機に含まれる蒸発器と蒸発器より低位置の少なくとも一つの室内機との間に、冷媒ポンプを介して二次冷媒を自然循環させるように冷媒液管及び冷媒ガス管を備えた吸収式冷温熱発生装置において、冷媒ポンプとそれぞれの室内機との間の冷媒液管に液位レベルスイッチを設け、冷媒ガス管に蒸発器の上端より突出する立上り管を形成し、立上り管と冷媒液管との間にバイパス管を接続するとともに、バイパス管に冷媒電磁弁を配置した構成でもよい。
【００１８】
このとき、冷媒電磁弁は、暖房時に全開されるとともに、冷房時に高負荷運転で全閉され、かつ低負荷運転及び運転停止で全開に制御される構成とする。
【００１９】
さらにバイパス管及び冷媒電磁弁の口径は、蒸発器内の蒸発コイルとほぼ等しい圧力損失を生じるように決められる構成でもよい。
【００２０】
そして空調装置においては、前記いずれか一つの吸収式冷温熱発生装置を備えてなる構成とする。
【００２１】
本発明によれば、暖房時のＨｉｇｈ運転では蒸発器管内で冷媒を蒸発させるために液面は最も低い位置にある。Ｌｏｗ運転では負荷が少ない分、蒸発器の上下間の位置に液面がある。ＯＦＦ運転では液面はさらに上昇するが、冷媒ガス管の立上り管より下部に冷媒液面が保持されるため、冷媒ガス管へ流入しない。
【００２２】
冷房時のＨｉｇｈ運転では、冷媒電磁弁を閉とし、Ｌｏｗ運転では冷媒電磁弁を開とし、滞留する冷媒ガスをバイパス管を通して上方へ逃がし、冷媒液管内に冷媒ガスを含まない冷媒液ヘッドを形成することにより、自然循環サイクルが早く形成される。
【００２３】
【発明の実施の形態】
本発明の一実施例を図１を参照しながら説明する。図１に示すように、高温再生器１及び低温再生器３等の再生器、分離器２、凝縮器４、吸収器５、蒸発器６、高温溶液熱交換器７及び低温溶液熱交換器８等を含む室外機１００と、蒸発器６内の蒸発コイル６Ａの下端と下降管５０Ａ及びＵ字管５０Ｂを経由して一つ以上の室内機５２，５３に接続された二次冷媒の冷媒液管５０と、冷媒液管５０のＵ字管５０Ｂに配置された冷媒ポンプ５７と、蒸発コイル６Ａの上端とそれぞれの室内機５２，５３とに接続された冷媒ガス管５１とを備えた吸収式冷温熱発生装置であって、冷媒ポンプ５７とそれぞれの室内機５２，５３との間の冷媒液管５０にその管内の液面を検出する液位レベルスイッチ７０を設け、冷媒ガス管５１に蒸発コイル６Ａの上端より突出する立上り管５１Ａを形成し、立上り管５１Ａと冷媒液管５０との間にバイパス管６４Ａ，６４Ｂを設け、バイパス管６４Ａ，６４Ｂに立上り管５１Ａへ近接させて冷媒電磁弁６０を配置し、暖房時に、冷媒電磁弁６０を全開に制御するとともに、低負荷〜停止（Ｌｏｗ〜ＯＦＦ）運転では負荷が少ないため、室内機５２，５３の膨張弁５４，５５の弁開度が小さくなり、冷媒液量が絞られるため液面低下による液位レベルスイッチ７０の作動又は室外機１００の高温再生器１での燃焼停止で冷媒ポンプ５７を停止し、冷房時に、冷媒電磁弁６０を高負荷（Ｈｉｇｈ）運転で全閉し、かつ低負荷運転又は停止運転で全開にする制御手段（コントローラ）５９を備えた構成とする。
【００２４】
そして図２に示すように、蒸発コイル６Ａの上端より上方に位置するレシーバー管６２と、蒸発コイル６Ａの下端とほぼ同一位置のレシーバー管６３とを設け、それぞれのレシーバー管６２，６３にバイパス管６４Ａ，６４Ｂ及び冷媒電磁弁６０を接続させ、蒸発コイル６Ａとほぼ等しい圧力損失を生じるようにバイパス管６４Ａ，６４Ｂ及び冷媒電磁弁６０の口径を決定する。この構造により暖房時に液面が安定し、バイパス管６４Ａに液面レベルスイッチを設けて液面高さにより冷媒ポンプ５７を起動発停制御する必要がなくなる。
【００２５】
本実施例の暖房時の動作を説明する。暖房時のＨｉｇｈ−Ｌｏｗ−ＯＦＦ運転では蒸発器６内の液面高さが異なり、Ｈｉｇｈ運転時は全負荷と考えると、全ての蒸発器伝熱面積を必要とし、蒸発器管６Ａ内で冷媒液を蒸発させるために液面は最も低いＡ０の位置にある。Ｌｏｗ運転時は負荷が少なく室内機５２，５３の運転台数が少ない。したがって、冷房時に一番圧力の低い室外機１００の蒸発器コイル６Ａ内に、室内機５２，５３の冷媒保有量に相当する量の冷媒液が溜ってきて蒸発器６内の液面が上昇し、蒸発器６の上下間の位置Ａ１に液面がある。ＯＦＦ運転時に液面はさらに上昇するが、その液面が冷媒ガス取り出し高さＡ３以下であれば、システム上、冷媒ガス管５１へ流入しない。すなわち室外機１００の高温再生器１の燃焼停止時に、冷媒ポンプ５７が停止する制御であればよい。能力制御で、Ｌｏｗ→ＯＦＦ運転の場合、負荷が少ないため、室内機５２，５３の膨張弁５４，５５は弁開度が小さくなって冷媒液量が絞られ、液面レベルスイッチ７０が作動すると、冷媒ポンプ５７を停止させる。その間、図示されるｈ３の間に液面があっても問題はない。室外機１００の高温再生器１の燃焼が始まると、蒸発により液面が低下してくる。暖房時は、冷媒電磁弁６０が開動作であり、バイパス管６４Ａ，６４Ｂをできるだけ小さい管径にして抵抗を大きくする。管径が大きくて蒸発コイル６Ａとの圧力差が大きいとその分、液面が押し上げられる。液面が高さＡ３の位置にならないように押さえることが必要である。
【００２６】
次に冷房時の動作を説明する。Ｈｉｇｈ運転時は全負荷分の能力が必要となるため、冷媒電磁弁６０を閉して冷媒ガスがバイパスしないようにするが、Ｌｏｗ運転時は冷媒電磁弁６０を開とし、レシーバー管６３内に滞留する冷媒ガスをバイパス管６４Ａ，６４Ｂを通して上方へ逃がし、均圧管作用で、冷媒液管５０内に冷媒ガスを含まない冷媒液ヘッド（液柱）を形成することにより本来の冷媒液圧力が形成され、冷媒液の落し込み効果で自然循環サイクルが早く形成される。したがってＬｏｗ運転時としては、バイパス管６４Ａ，６４Ｂは圧力損失が小さくなるようにできるだけ大きい口径が望ましい。
【００２７】
【発明の効果】
本発明によれば、冷媒ガス管に立上り管と、立上り管と冷媒液管との間にバイパス管及び冷媒電磁弁を設けたため、冷房時の低負荷運転で冷媒ガスの液封が除去されて負荷の変化時間が短縮され、暖房時についても冷媒ポンプの制御が簡素化されて発停頻度が低減されるとともに、暖房時の安定運転が保持され、装置がコンパクトになる効果がある。
【図面の簡単な説明】
【図１】本発明の一実施例を示す図である。
【図２】図１の要部を示す図である。
【図３】従来の室外機を示す図である。
【図４】従来の空調装置を示す図である。
【符号の説明】
１ 高温再生器 ２ 分離器
３ 低温再生器 ４ 凝縮器
５ 吸収器 ６ 蒸発器
６Ｂ 冷媒分配器 ７ 高温溶液熱交換器
８ 低温溶液熱交換器 ８Ａ 濃溶液管
９ 溶液循環ポンプ １０ 冷暖切換弁
１０Ａ 管路 １１ 水冷媒比例弁
１１Ａ 管路 １１Ｂ 水冷媒管
１２ 凍結防止弁 １２Ａ 管路
１３ 溶液バイパス弁 １３Ａ 管路
１４ 冷却水循環ポンプ １５ 冷温水循環ポンプ
１６ 冷水出口温度センサ １７ 蒸発器温度センサ
２１ 冷媒液温度センサ ２２ 溶液バイパス弁
２５ 冷却水入口温度センサ ４０，４１ 冷却水管
４２ クーリングタワー ４２Ａ 送風機
４３，４４ 冷温水管 ５０ 冷媒液管
５１ 冷媒ガス管 ５１Ａ 立上り管
５２，５３ 室内機 ５４，５５ 膨張弁
５６ 冷暖切換弁 ５７ 冷媒ポンプ
５８ 逆止弁 ５９ コントローラ
６０ 冷媒電磁弁 ６４Ａ，６４Ｂ バイパス管
７０ 液面レベルスイッチ ７１ ポンプコントローラ
１００ 室外機[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air conditioner having an indoor unit and an outdoor unit, and more particularly, to an absorption-type cold / hot heat generator using a phase-change secondary refrigerant.
[0002]
[Prior art]
As a conventional absorption-type cooling / heating heat generating apparatus, an air conditioning apparatus using an absorption cooling / heating water heater (outdoor unit) having a configuration shown in FIG. 3 is known. The air conditioner includes an absorption chiller / heater 100 that generates cooling / heating heat, a cooling tower 42 connected to the absorption chiller / heater 100 via cooling water pipes 40 and 41 for cooling the cooling water, and a cooling water pipe interposed in the cooling water pipe 41 for cooling water. A cooling water circulation pump 14 that circulates from the cooling tower 42 to the absorption chiller / heater 100, and an air conditioner (not shown) that is connected to the absorption chiller / heater 100 via the cooling and heating water pipes 43 and 44 and that is disposed in the air conditioned space and exchanges heat with the air in the space. A cold / hot water circulation pump 15 for circulating the secondary refrigerant interposed between the cold / hot water pipes 43 and filled in the cold / hot water pipes 43 and 44 between the absorption cold / hot water machine 100 and the air conditioning indoor unit; It is comprised including.
[0003]
In contrast to the indoor unit for air conditioning, the absorption chiller-heater 100, which is usually called an outdoor unit together with the cooling tower 42, has a high-temperature regenerator 1 that burns fuel and heats a dilute solution with the heat thereof. A separator 2 for separating the refrigerant vapor and the intermediate concentrated solution from the heated dilute solution, a low-temperature regenerator 3 for heating the intermediate concentrated solution using the separated refrigerant vapor as a heat source and further generating a secondary refrigerant vapor, A condenser 4 for cooling and condensing and liquefying the refrigerant vapor passing through the low-temperature regenerator 3 and the secondary refrigerant vapor generated in the low-temperature regenerator 3 to generate a liquid refrigerant, and a liquid refrigerant generated by the condenser 4 are provided. An evaporator 6 for cooling the secondary refrigerant in the evaporator coil by dropping and evaporating the refrigerant from the refrigerant distributor 6B onto an evaporator coil similarly provided therein; and an absorber for absorbing the refrigerant vapor evaporated by the evaporator 6 into a concentrated solution to generate a dilute solution. Vessel 5 and pressurized dilute solution A solution circulating pump 9 which feeds into the high temperature regenerator 1 through the heated fluid side of the low temperature solution heat exchanger 8 and the high temperature solution heat exchanger 7, and the bottom of the separator 2 and the bottom of the evaporator 6 via a cooling / heating switching valve 10. And a concentrated solution pipe 8A connecting the heated fluid outlet side of the low-temperature solution heat exchanger 8 to the upper part of the absorber 5, and a solution bypass valve 13 connected to the concentrated solution pipe 8A and the lower part of the absorber 5. 13A, a pipe 12A connecting the concentrated solution pipe 8A and the refrigerant distributor 6B provided in the evaporator 5 through the antifreeze valve 12, and a refrigerant distributor attached to the refrigerant distributor 6B. An evaporator temperature sensor 17 for detecting the temperature of the refrigerant in the refrigerant refrigerant 6B, a water refrigerant pipe 11B for guiding the liquid refrigerant from the condenser 4 to the refrigerant distributor 6B, and a water refrigerant proportional valve 11 connected in parallel to the water refrigerant pipe 11B. And a pipeline 11A to be interposed.
[0004]
Further, the intermediate concentrated solution separated by the separator 2 is guided to the low temperature regenerator 3 via the heating fluid side of the high temperature solution heat exchanger 7, and the refrigerant is evaporated by the low temperature regenerator 3 to become a concentrated solution. The conduit is configured to be guided to the concentrated solution pipe 8A via the heated fluid side of the low-temperature solution heat exchanger 8. Each of the absorber 5 and the condenser 4 is provided with a cooling water coil, and the outlet of the cooling water coil of the absorber 5 is connected to the inlet of the cooling water coil of the condenser 4. The inlet is connected to the cooling water pipe 41, and the outlet of the cooling water coil of the condenser 4 is connected to the cooling water pipe 40. The cold / hot water pipe 43 is connected to the inlet side of the evaporator coil 6A of the evaporator 6, and the cold / hot water pipe 44 is connected to the outlet side of the evaporator coil 6A of the evaporator 6, respectively. A chilled water outlet temperature sensor 16 for detecting a temperature is mounted.
[0005]
As a secondary refrigerant that circulates heat between the indoor unit and the outdoor unit to transfer heat, a fluid that does not change phase, generally a liquid has been used.In recent years, by causing the secondary refrigerant to change phase, Devices that increase the amount of heat transport per unit flow rate have been developed. FIG. 4 shows an example of such a configuration. In the configuration shown in FIG. 3, the refrigerant liquid pipe 50 and the refrigerant gas pipe 51 are connected to the lower end and the upper end of the evaporation coil 6A, respectively, instead of the cold and hot water pipes 43 and 44. Have been. The other ends of the refrigerant liquid pipe 50 and the refrigerant gas pipe 51 are branched by the number of indoor units 52 and 53 arranged below the evaporating coil 6A. The lower inlets of the heat exchangers 52 and 53 are connected via expansion valves 54 and 55, respectively, and the branch end of the refrigerant gas pipe 51 is connected to the upper inlet of the heat exchanger. A refrigerant liquid temperature sensor 21 that detects the temperature of the secondary refrigerant and outputs it to the controller 59 as an electric signal is mounted near the connection between the refrigerant liquid pipe 50 and the evaporating coil 6A.
[0006]
The refrigerant liquid pipe 50 has a portion (U-shaped pipe) disposed at a lower position than the indoor units 52 and 53 on the way, and a refrigerant pump 57 for pressurizing the refrigerant liquid and sending the refrigerant liquid to the evaporation coil 6A is attached thereto. I have. A check valve 58 is provided on the discharge side of the refrigerant pump 57, and the outlet side of the check valve 58 and the suction side of the refrigerant pump 57 are connected via a cooling / heating switching valve 56. HFC-134a is filled in a refrigerant liquid pipe as a secondary refrigerant that changes phase (hereinafter, also simply referred to as refrigerant). The other configuration is the same as the description of FIG. 3, and the description is omitted.
[0007]
The operation of the air conditioner shown in FIG. 4 during cooling is as follows. During cooling, the cooling / heating switching valve 56 is open. The refrigerant vapor (HFC-134a) is cooled and condensed by the evaporator coil 6A of the evaporator 6 to become a refrigerant liquid, flows downward through the refrigerant liquid pipe 50 by gravity, passes through the expansion valves 54 and 55, and the respective indoor units 52 and 53. Into the heat exchanger. The refrigerant liquid that has flowed into the heat exchanger evaporates by removing the heat of the air in the air-conditioned space, becomes refrigerant vapor, rises through the refrigerant gas pipe 51, and flows into the evaporation coil 6A of the evaporator 6. Since the outdoor unit 100 is operated in the cooling mode, the evaporation coil 6A of the evaporator 6 is cooled by evaporation of the water refrigerant dropped on the surface thereof, and the refrigerant vapor (HFC-134a) flowing into the evaporation coil 6A. Is condensed and liquefied. Due to the condensation and liquefaction, the pressure inside the evaporation coil 6A decreases, and the refrigerant vapor evaporated in the heat exchangers of the indoor units 52 and 53 is sucked into the evaporator 6. Since the refrigerant liquid condensed and liquefied inside the evaporation coil 6A flows into the indoor units 52 and 53 by gravity, the refrigerant (HFC-134a) during cooling naturally circulates, and there is no need to drive the refrigerant by the refrigerant pump.
[0008]
When the cooling operation is started, the pressure inside the evaporation coil 6A decreases as described above, and the saturated refrigerant vapor in the refrigerant gas pipe 51 flows into the evaporation coil 6A due to the pressure difference. The refrigerant liquid generated by condensation in the evaporation coil 6A flows down by its own weight in the refrigerant liquid pipe 50, and the refrigerant liquid head (liquid column) rises. In order for the natural circulation of the refrigerant to be established, it is sufficient that (refrigerant liquid head)-(refrigerant gas head) is equal to or greater than the total pressure loss of the refrigerant circulation path. That is, the natural circulation of the refrigerant is not started until a liquid head satisfying the following expression is formed. This means that the heat load supplied to the evaporator 6 at the start of the cooling operation is small.
[0009]
(Equation 1)
[0010]
During heating, the cooling / heating switching valve 56 is closed. The refrigerant liquid (HFC-134a) is heated by the evaporator coil 6A of the evaporator 6 to become a refrigerant vapor, flows down the refrigerant gas pipe 51, and flows into the heat exchangers of the indoor units 52 and 53. The refrigerant vapor that has flowed into the heat exchanger is deprived of heat by the air in the air-conditioned space, condensed and liquefied, becomes a refrigerant liquid, flows down the refrigerant liquid pipe, and flows into the refrigerant pump 57 inlet. The refrigerant liquid is pressurized by the refrigerant pump 57, flows into the evaporator coil 6A of the evaporator 6, and repeats the above cycle. At this time, the outdoor unit 100 is operated in the heating mode, the high-temperature solution separated by the separator 2 is guided to the evaporator 6, and the evaporation coil 6A is heated by this heat.
[0011]
Here, when the phase control of the High-Low-OFF in the cold bunch operation, the pressure of the refrigerant gas pipe and the refrigerant liquid pipe varies. During the High operation, there is also a pressure difference between the refrigerant gas pipe and the refrigerant liquid pipe, and the saturated refrigerant vapor does not stay in the refrigerant liquid pipe. On the other hand, when Low~OFF operation, becomes supercooled, the refrigerant liquid reservoir is, the pressure difference between the state where the evaporation coil is liquid seal and the Do Ri refrigerant gas pipe and refrigerant liquid pipe is reduced in evaporation coils, A normal refrigerant liquid head cannot be obtained. Therefore, the driving force for natural circulation is weakened.
[0012]
Also during heating High (high load) -Low (low load) -OFF (STOP) is that Do different liquid level of the refrigerant in the evaporator coil operation. During Low operation, if the load is small and the number of operating indoor units is small , the amount of refrigerant corresponding to the refrigerant holding amount of the indoor units accumulates in the evaporator coil of the outdoor unit with the lowest pressure during cooling , The liquid level in the evaporator rises. (However, the required heat transfer area during the Low operation is still secured.) In the OFF operation, the liquid level may further rise and flow into the refrigerant gas pipe, and refrigerant gas may be mixed in the refrigerant liquid pipe. And the liquid level may be unstable. So the bypass pipe of the refrigerant is provided between the refrigerant liquid pipe and the refrigerant gas pipe, Ru provided refrigerant solenoid valve is a two-way valve in the bypass pipe. Then , the refrigerant solenoid valve is opened in all modes during the heating operation, and closed in all modes during the cooling operation, the refrigerant gas in the refrigerant liquid is released to the refrigerant gas pipe via the bypass pipe, and the liquid level changes. Is detected by the liquid level switch to start and stop the refrigerant pump . However , ON / OFF start / stop of the refrigerant pump is controlled by two liquid level switches together with the liquid level switch on the side of the refrigerant pump. For stable operation as a system, it is better to operate the refrigerant pump continuously during heating, and to protect the refrigerant pump, install a receiver upstream of the refrigerant pump and monitor the liquid level. Operation control without cavitation is an essential requirement.
[0013]
[Problems to be solved by the invention]
In the absorption-type cold / hot heat generator as described above, in High operation during cooling, there is a pressure difference between the inside of the refrigerant gas pipe and the inside of the refrigerant liquid pipe, and the saturated refrigerant vapor does not stay in the refrigerant liquid pipe. On the other hand, Low～OFF during operation becomes supercooled, Ri refrigerant liquid reservoir into the evaporation coil, a state where the evaporation coil is liquid-sealed, because the pressure difference is small between the refrigerant gas pipe and the refrigerant liquid pipe, A normal refrigerant liquid head cannot be obtained . For this reason, there is a problem that the driving force for natural circulation is weakened.
[0014]
Further, the liquid level in the evaporator rises in the Low operation at the time of heating, and further rises in the OFF operation, and the refrigerant liquid flows into the refrigerant gas pipe . In addition, there is a problem that the refrigerant gas is mixed in the refrigerant liquid pipe and the liquid level becomes unstable. Further, if the start and stop of the refrigerant pump are controlled by two liquid level switches during heating, there is a problem that frequent start and stop are performed and stable operation cannot be performed.
[0015]
An object of the present invention is to provide an absorption-type cold / hot heat generation device that can naturally circulate during cooling using a secondary refrigerant that changes in phase and continuously operate a refrigerant pump during heating.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, an absorption-type cold / hot heat generating apparatus according to the present invention includes an outdoor unit including a regenerator, a condenser, an absorber and an evaporator, a lower end of an evaporator coil in the evaporator, a downcomer pipe, and a U. A refrigerant liquid pipe of a secondary refrigerant connected to at least one indoor unit via a U-shaped pipe, a refrigerant pump disposed on a U-shaped pipe of the refrigerant liquid pipe, and an upper end of an evaporation coil and each indoor unit. In an absorption type cold / hot heat generating device having a connected refrigerant gas pipe, a liquid level switch is provided in a refrigerant liquid pipe between a refrigerant pump and each indoor unit, and the refrigerant gas pipe projects from an upper end of an evaporation coil. Forming a riser pipe, connecting a bypass pipe between the riser pipe and the refrigerant liquid pipe, disposing a refrigerant solenoid valve in close proximity to the riser pipe in the bypass pipe, and controlling the refrigerant solenoid valve to fully open during heating. And the liquid level level A control means for stopping the refrigerant pump when the switch is operated or stopping the combustion of the outdoor unit, and for cooling, the refrigerant solenoid valve is fully closed in a high-load operation and fully opened in a low-load operation or a stop operation. I do.
[0017]
And an absorption unit provided with a refrigerant liquid pipe and a refrigerant gas pipe between the evaporator included in the outdoor unit and at least one indoor unit located at a position lower than the evaporator so as to naturally circulate the secondary refrigerant via a refrigerant pump. In the type cold / hot heat generator, a liquid level switch is provided in a refrigerant liquid pipe between a refrigerant pump and each indoor unit, a riser pipe protruding from an upper end of an evaporator is formed in a refrigerant gas pipe, and a riser pipe and a refrigerant are formed. A configuration in which a bypass pipe is connected to the liquid pipe and a refrigerant solenoid valve is arranged in the bypass pipe may be used.
[0018]
At this time, refrigerant solenoid valve, while being fully opened during heating, fully closed is a high load operation during cooling, and a configuration that is controlled to fully open at a low load operation and shutdown.
[0019]
Further, the diameter of the bypass pipe and the diameter of the refrigerant solenoid valve may be determined so as to generate a pressure loss substantially equal to that of the evaporation coil in the evaporator.
[0020]
The air conditioner is provided with any one of the above-mentioned absorption type cold and hot heat generating devices.
[0021]
According to the present invention, in the High operation at the time of heating, the liquid level is at the lowest position to evaporate the refrigerant in the evaporator tube. In the Low operation, there is a liquid level at a position between the upper and lower sides of the evaporator because the load is small. In the OFF operation, the liquid level further rises, but does not flow into the refrigerant gas pipe because the refrigerant liquid level is held below the rising pipe of the refrigerant gas pipe.
[0022]
In the High operation at the time of cooling, the refrigerant solenoid valve is closed, and in the Low operation, the refrigerant solenoid valve is opened, and the stagnant refrigerant gas is released upward through the bypass pipe to form a refrigerant liquid head containing no refrigerant gas in the refrigerant liquid pipe. By doing so, a natural circulation cycle is formed quickly.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, regenerators such as a high-temperature regenerator 1 and a low-temperature regenerator 3, a separator 2, a condenser 4, an absorber 5, an evaporator 6, a high-temperature solution heat exchanger 7, and a low-temperature solution heat exchanger 8 And the refrigerant liquid of the secondary refrigerant connected to one or more indoor units 52 and 53 via the lower end of the evaporator coil 6A in the evaporator 6, the downcomer pipe 50A and the U-shaped pipe 50B. An absorption type including a pipe 50, a refrigerant pump 57 disposed in the U-shaped pipe 50 </ b> B of the refrigerant liquid pipe 50, and a refrigerant gas pipe 51 connected to the upper end of the evaporating coil 6 </ b> A and the indoor units 52 and 53. In the cooling / heating heat generating apparatus, a liquid level switch 70 for detecting a liquid level in the refrigerant liquid pipe 50 between the refrigerant pump 57 and the indoor units 52 and 53 is provided, and the refrigerant gas pipe 51 evaporates. A rising pipe 51A protruding from the upper end of the coil 6A is formed and Bypass pipes 64A, 64B are provided between 51A and refrigerant liquid pipe 50, and refrigerant electromagnetic valve 60 is arranged in bypass pipes 64A, 64B in close proximity to riser pipe 51A, and controls refrigerant electromagnetic valve 60 to fully open during heating. In addition, since the load is small in the low load to stop (Low to OFF) operation, the opening degrees of the expansion valves 54 and 55 of the indoor units 52 and 53 are reduced, and the refrigerant liquid amount is reduced, so that the liquid level is reduced. The refrigerant pump 57 is stopped by the operation of the level switch 70 or the stop of combustion in the high temperature regenerator 1 of the outdoor unit 100, and during cooling, the refrigerant solenoid valve 60 is fully closed in a high load (High) operation, and the low load operation is performed. Alternatively, a configuration is provided in which a control means (controller) 59 for fully opening in the stop operation is provided.
[0024]
As shown in FIG. 2, a receiver tube 62 located above the upper end of the evaporation coil 6A and a receiver tube 63 at substantially the same position as the lower end of the evaporation coil 6A are provided, and a bypass tube is provided in each of the receiver tubes 62 and 63. The diameters of the bypass pipes 64A and 64B and the refrigerant solenoid valve 60 are determined so that the pressure loss is substantially equal to that of the evaporation coil 6A by connecting the refrigerant valves 64A and 64B and the refrigerant solenoid valve 60. With this structure, the liquid level is stabilized during heating, and it is not necessary to provide a liquid level switch in the bypass pipe 64A and control the start / stop of the refrigerant pump 57 based on the liquid level.
[0025]
The operation of this embodiment during heating will be described. Different liquid level in the evaporator 6 in High-Low-OFF operation of the heating, High during operation considering that full load, require all of the evaporator heat transfer area, the refrigerant in the evaporator tubes 6A liquid surface to evaporate the liquid is in the position of the lowest a 0. At the time of the Low operation, the load is small and the number of operating indoor units 52 and 53 is small . Therefore, during cooling, the amount of refrigerant liquid corresponding to the refrigerant holding amount of the indoor units 52 and 53 is accumulated in the evaporator coil 6A of the outdoor unit 100 having the lowest pressure, and the liquid level in the evaporator 6 rises. , there is a liquid level position a 1 between the upper and lower evaporator 6. Liquid level rises further during OFF operation, but if the liquid level height A 3 or less was taken out refrigerant gas, the system does not flow into the refrigerant gas pipe 51. That is, any control may be used as long as the refrigerant pump 57 stops when the high-temperature regenerator 1 of the outdoor unit 100 stops burning. In the case of low-to-off operation in the capacity control, when the load is small, the expansion valves 54 and 55 of the indoor units 52 and 53 have a small valve opening degree, the refrigerant liquid amount is reduced, and the liquid level switch 70 operates. Then, the refrigerant pump 57 is stopped. Meanwhile, there is no problem even if the liquid level between h 3 illustrated. When the high-temperature regenerator 1 of the outdoor unit 100 starts burning, the liquid level decreases due to evaporation. At the time of heating, the refrigerant solenoid valve 60 is in the opening operation, and the bypass pipes 64A and 64B are made as small as possible in diameter to increase the resistance. When the pipe diameter is large and the pressure difference from the evaporation coil 6A is large, the liquid level is raised accordingly. It is necessary to press so that the liquid surface is not a position of the height A 3.
[0026]
Next, the operation during cooling will be described. For High during operation that requires a full load amount of capacity, although the refrigerant gas closed refrigerant solenoid valve 60 to block the bypass, Low during operation and open the refrigerant solenoid valve 60, into the receiver tube 63 The stagnant refrigerant gas is released upward through the bypass pipes 64A and 64B , and an original refrigerant liquid pressure is formed by forming a refrigerant liquid head (liquid column) containing no refrigerant gas in the refrigerant liquid pipe 50 by the pressure equalizing pipe action. As a result, the natural circulation cycle is quickly formed by the effect of the coolant liquid dropping. Therefore, at the time of the Low operation, it is desirable that the bypass pipes 64A and 64B have as large a diameter as possible so as to reduce the pressure loss.
[0027]
【The invention's effect】
According to the present invention, the riser pipe and the bypass pipe and the refrigerant solenoid valve are provided between the riser pipe and the refrigerant liquid pipe in the refrigerant gas pipe, so that the liquid seal of the refrigerant gas is removed in the low load operation during cooling. The load change time is shortened, the control of the refrigerant pump during heating is simplified, the frequency of starting and stopping is reduced, and stable operation during heating is maintained, and the device is compact.
[Brief description of the drawings]
FIG. 1 is a diagram showing one embodiment of the present invention.
FIG. 2 is a diagram showing a main part of FIG. 1;
FIG. 3 is a view showing a conventional outdoor unit.
FIG. 4 is a diagram showing a conventional air conditioner.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 high temperature regenerator 2 separator 3 low temperature regenerator 4 condenser 5 absorber 6 evaporator 6B refrigerant distributor 7 high temperature solution heat exchanger 8 low temperature solution heat exchanger 8A concentrated solution pipe 9 solution circulation pump 10 cooling / heating switching valve 10A pipe Channel 11 Water refrigerant proportional valve 11A Pipe 11B Water refrigerant pipe 12 Antifreeze valve 12A Pipe 13 Solution bypass valve 13A Pipe 14 Cooling water circulation pump 15 Cold and hot water circulation pump 16 Cold water outlet temperature sensor 17 Evaporator temperature sensor 21 Refrigerant liquid temperature sensor 22 Solution bypass valve 25 Cooling water inlet temperature sensor 40, 41 Cooling water pipe 42 Cooling tower 42A Blower 43, 44 Cooling / heating water pipe 50 Refrigerant liquid pipe 51 Refrigerant gas pipe 51A Rise pipe 52, 53 Indoor unit 54, 55 Expansion valve 56 Cooling / heating switching valve 57 Refrigerant pump 58 Check valve 59 Controller 60 Refrigerant solenoid valve 64A, 64B Bypass 70 liquid level switch 71 the pump controller 100 outdoor unit
