JP3780834B2

JP3780834B2 - Air conditioner

Info

Publication number: JP3780834B2
Application number: JP2000278662A
Authority: JP
Inventors: 一朗藤林; 勉井本; 信夫稲垣; 昭二高久; 啓夫中村
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2000-09-08
Filing date: 2000-09-08
Publication date: 2006-05-31
Anticipated expiration: 2020-09-08
Also published as: JP2002081803A

Description

【０００１】
【発明の属する技術分野】
本発明はＲ２２，Ｒ４０７ＣあるいはＲ４１０Ａ等の冷媒を使用している空気調和機等において、気液分離器を設けてガスインジェクションが可能な冷凍サイクルとした空気調和機に関するものである。
【０００２】
【従来の技術】
圧縮機、四方弁、冷房時に凝縮器として暖房時に蒸発器として機能する室外熱交換器、第１の減圧装置、気液分離器、第２の減圧装置、暖房時に凝縮器として冷房時に蒸発器として機能する室内熱交換器を順次配管によって接続する冷凍サイクルとし、気液分離器にて分離したガス冷媒を圧縮機の中間圧力段に注入する所謂ガスインジェクション回路を有する冷凍サイクルが実開平１-８８３６２号（実願昭６２-１８３７４６号のマイクロフィルム、以下文献という）に記載されている。
【０００３】
この文献に記載された気液分離器は、それぞれ減圧装置と接続される第１冷媒管及び第２冷媒管を、円筒形状の容器底面から立設された遮蔽板によって区画された２つの空間にそれぞれ容器側面から挿入し、それぞれの先端を底面方向に曲げた構造となっている。そして、一方の冷媒管から流入した気液２相冷媒は筒体容器の底面に衝突し、容器内面と遮蔽板側面とで形成される空間を上昇し、液冷媒は他方の冷媒管が挿入されている隣の空間へ、ガス冷媒は容器上部に挿入されたガスインジェクション回路を構成する配管へと導かれることで、二相流冷媒が気液分離される。
【０００４】
【発明が解決しようとする課題】
ところで、この文献では、気液分離器の構造が記述されているものの、気液分離器の形状や寸法について論じておらず、形状や寸法によっては充分気液に分離されず、気相の混じった冷媒が液保存室空間に流入してそのまま下流側冷媒管から流出してしまう問題がある。
【０００５】
本発明の目的は、冷媒の気液分離精度がよい気液分離器の形状や寸法を提供することにある。
【０００６】
【課題を解決するための手段】
上記目的は、圧縮機、熱源側となる第１熱交換器、第１減圧器、気液分離器、第２減圧器、利用側となる第２熱交換器とを順次配管で接続した冷凍サイクルと、この気液分離器と前記圧縮機とを配管によって接続するインジェクション回路とを備えた空気調和機において、前記気液分離器を、筒状容器底面に遮蔽板を設け、前記第１減圧器に接続された第１冷媒管及び前記第２減圧器に接続された第２冷媒管をこれら冷媒管下端が前記遮蔽板と気液分離器の容器内壁面によって囲まれる空間まで挿入し、前記インジェクション回路に接続される第３の冷媒管を前記気液分離器上部に挿入して構成し、前記遮蔽板の上端から前記冷媒管の下端までの距離を７ｍｍから１５ｍｍの範囲になるようにすることで達成される。
【０００７】
さらに、上記目的は、圧縮機、熱源側となる第１熱交換器、第１減圧器、気液分離器、第２減圧器、利用側となる第２熱交換器とを順次配管で接続した冷凍サイクルと、この気液分離器と前記圧縮機とを配管によって接続するインジェクション回路とを備えた空気調和機において、前記気液分離器を、筒状容器底面に遮蔽板を設け、前記第１減圧器に接続された第１冷媒管及び前記第２減圧器に接続された第２冷媒管をこれら冷媒管下端が前記遮蔽板と気液分離器の容器内壁面によって囲まれる空間まで挿入し、前記インジェクション回路に接続される第３の冷媒管を前記気液分離器上部に挿入して構成し、前記筒状容器の底面を平面状にし、前記筒状容器の内径を３６ｍｍから５５ｍｍの範囲にし、前記第１及び第２の冷媒管の下端から筒状容器の内底面までの距離を８ｍｍから１５ｍｍの範囲になるようにし、前記遮蔽板の上端から前記冷媒管の下端までの距離を７ｍｍから１５ｍｍの範囲になるようにすることで達成される。
【０００９】
【発明の実施の形態】
以下本発明の実施の形態を図を用いて説明する。図１は、本実施の形態に係る気液分離器を用いたガスインジェクション可能な冷凍サイクルの構成を示したものである。インジェクション可能な圧縮機１（インジェクションポートを設けたレシプロ、ロータリ、スクロール圧縮機、文献と同様２段圧縮機等がある）、サイクルの冷媒流れ方向を変更し冷房と暖房を切り替える四方弁８、熱源側の第１熱交換器２、第１減圧器で本実施の形態では電動膨張弁３、気液分離器４、第２減圧器で本実施の形態では電動膨張弁５、利用側の第２熱交換器６が順次配管によって接続して冷凍サイクルが構成され、気液分離器４から圧縮機１へのインジェクション量を制御する流量調整弁７を介してインジェクションガスを圧縮室１内に取り込むためのインジェクションポート９に配管により接続することでガスインジェクション回路が形成される。
【００１０】
次に、図２に気液分離器４の一実施の形態を示した。筒状の本体（容器）２０に図１の冷凍サイクルへの接続用としての冷媒管を設けた構成となっている。筒状本体２０は円環状の容器側面を構成する筒体１３と上フタ１４及び下フタ１５から形成されている。容器底面（下フタ１５の内面）から遮蔽板１６が立設されることで容器内の下部空間が第１冷媒室１７及び第２冷媒室１８に区画されている。第１減圧器３に接続される第１冷媒管１０、及び第２減圧器５に接続される第２冷媒管１１は、それぞれ先端が第１冷媒室１７及び第２冷媒室１８内となるように、上フタ１４から挿入される。流量制御弁７に接続される第３冷媒管１２は上フタ１４の内面より筒上本体２０の内部に若干飛び出る位置まで挿入されている。
【００１１】
また、図示するように、第１冷媒管１０と第２冷媒管１１の間に設けられた遮蔽版１６の下フタ１５内面からの高さをｂとし、第１および第２冷媒管１０、１１の先端は下フタ１５の内面より長さａのギャップが開けられている。
【００１２】
以上説明した冷凍サイクルにおいて、冷房運転時における動作を次に説明する。なお、図１において冷房時の冷媒の流れる方向は破線矢印にて示されている。圧縮機１によって圧縮された高温高圧のガス冷媒は四方弁８を介して凝縮器となる第１熱交換器２に至る。第１熱交換器２よって凝縮された低温高圧の液冷媒は、第１減圧器３にて圧縮機１の吸込圧力と吐出圧力の間の中間圧に減圧されて気液二相流となって第１冷媒管１０より気液分離器４内に入る。
【００１３】
第１冷媒管１０を通過した冷媒は下フタ１５に衝突し、遮蔽版１６と筒体１３で形成されるる空間（第１冷媒室１７）に沿って上昇する。この上昇過程で、比重の小さいガス冷媒と比重の大きい液冷媒に分離される。ガス冷媒は重力に抗して筒体１３内に拡散され、上部の第３冷媒管１２へ入り、開となっている流量調節弁７を介してインジェクションポート９から圧縮機１内にインジェクションされる。
【００１４】
これに対して、第1冷媒室１７に残った液冷媒は、遮蔽板１６を乗り越えて第２冷媒管側で遮蔽板と筒体で形成される空間（第2冷媒室１８）に流れ込んで第２冷媒室１８に溜まり、さらに第２冷媒管１１を通って第２減圧弁５へと向かい、減圧された後蒸発器となる第２熱交換器６に流入し、室内の空気と熱交換することにより蒸発して高温低圧のガス冷媒となり四方弁８を介して圧縮機の吸入パイプに至る。
【００１５】
さて、第2冷媒室１８に溜まった冷媒の液面高さが第２冷媒管１１の下端より高く、かつガス冷媒を含まなければ第２冷媒管１１からは液冷媒のみが流れ出すことになる。このような動作の結果、第１冷媒管１０より入ってきた気液二相流中のガス冷媒を第３冷媒管１２、液冷媒を第２冷媒管１１へ流すことにより気液分離することができる。
【００１６】
この冷房サイクルの場合、気液分離性を向上するためには、第２冷媒室１８に溜まる冷媒にガス冷媒が混入しないようにすることが重要である。このためには、第１冷媒室１７及び第2冷媒室１８に溜まる冷媒の乱れをできるだけ抑える必要があり、このための最も有効な方法は筒体１３内の断面積を大きくして第１および第2冷媒室１７、１８内の冷媒流速を下げることである。ここで特に第１冷媒室１７の断面積を大きくすると、第１冷媒管１０から出てきた冷媒の流速は減速され、気相と液相の密度差により気液分離しやすくなる。しかし、断面積を大きくすることは、筒体１３の径を大きくすることであり、気液分離器４が大型化することになる。この結果、冷凍サイクルを収納する機械室内での気液分離器の占有空間が大きくなり、ひいては室外機全体が大型化するという問題が生じる。
【００１７】
そこで、気液分離器としては、十分な気液分離性能を確保しつつ、かつできるだけ筒体の径を抑える必要がある。
【００１８】
また、暖房の場合、冷媒の流れが逆転し、第１冷媒管１０と第２冷媒管１１の関係および第１冷媒室１７と第2冷媒室１８との関係が逆転する。このため第2冷媒室１８は冷媒の入口空間となるので、ここでも流速を遅くするために断面積を広げる必要がある。なお、冷房と暖房とでは冷媒の流れが逆転するだけで、冷媒の振る舞いは冷房と同様である。
【００１９】
ところで気液分離器４の容器内圧力は２０ｋｇ／ｃｍ２以上の高圧になるので圧力容器でなければならない。圧力容器としては球形が最も優れているが、製作が難しく高価となるので、スクロール圧縮機やロータリ圧縮機などの密閉容器と同様、円筒形とする。上記のように、気液分離器４の底面には遮蔽板１６が配置されるため、この遮蔽板を下フタ１５の中心を通る位置に置くと、第１冷媒室１７及び第２冷媒室１８ともに横断面が半円形状となる。このような冷媒室に冷媒管を挿入するため、下フタ１７の内面と衝突した冷媒は上昇する際に、例えば遮蔽板１６と冷媒管との間等の狭い部分では流速が増し、広い部分では流速が遅くなる。このため、冷媒管の径を変えずに気液分離器の内径を変化させると気液分離性能の面から何らかの最適な条件が見出されるはずである。
【００２０】
図３は、一例として、ＪＩＳ定格条件で定格冷房能力２．８ｋＷのルームエアコンを用いて、気液分離器４の筒体１３の内径を変えたときの冷房及び暖房のガスインジェクションによる性能向上の実測結果を、横軸に筒体１３の内径、縦軸にルームエアコンのＣＯＰ（能力／入力）の向上率を取ってプロットしたものである。なお、遮蔽板１６の厚みは０．５ｍｍから０．８ｍｍ、挿入した冷媒管の外径は9．５２ｍｍのものを用いた。
【００２１】
この図より、冷房の場合には筒体１３の内径の広い範囲にわたってＣＯＰを向上できるが、暖房の場合には筒体１３の内径が約３６ｍｍ以下ではＣＯＰが下がってしまう。これより、冷房及び暖房の場合ともにＣＯＰを向上させるには筒体１３の内径を約３６mm以上にする必要がある。また筒体１３の内径が４０ｍｍ〜５５ｍｍ位では冷房及び暖房の場合ともＣＯＰの向上率はあまり変わらずしかも高い値が得られている。
【００２２】
但し、冷房の場合には筒体１３の内径が４９ｍｍ位からＣＯＰ向上率が低下する傾向を示している。これは、気液分離器４内に流入する二相流における気体の割合が暖房に比べて冷房の方が大きく、気体の冷媒は細い冷媒管１０から急激に内径が大きくなる筒体１３内を広がり、そして内径が小さい第３冷媒管１２へと吸い込まれていく。筒体１３の内径を大きくしすぎると、ＣＯＰ向上率が低下していく理由は、冷媒が第1接続管１０から筒状の本体２０内に流出するときの拡大損失や、筒状の本体２０から第３接続管１２に流入するときの縮小損失が増大することが関係していると考えられる。一方暖房では、気体の割合が少なく、流速を低下、筒体１３の内径を大きくした方が分離率が向上するため、冷房時にＣＯＰ向上率が低下する内径レベルではまだ低下する傾向が示されない。
【００２３】
従って、筒体１３の内径を決める要素は、内径の下限は、暖房時のＣＯＰ向上率によって決め、内径の上限は冷房時のＣＯＰ向上率によって決めるという考え方に基づく。
【００２４】
以上に述べた気液分離器４をできるだけコンパクトにしたいこと及び図４の結果から、筒体１３の内径としては、ＣＯＰの向上効果を得るためには３５〜５５ｍｍ位にする必要があり、特に冷房及び暖房の場合とも高いＣＯＰ向上率を得るためには４０〜５５ｍｍ位の範囲が最も適切である。
【００２５】
冷媒室内における冷媒流の乱れが発生する原因は、冷房の場合を考えると、冷媒が第１冷媒管１０から第１冷媒室１７に噴出するときの流れの速度が考えられる。この冷媒の噴出速度を落とすには、第１冷媒管１０の内径を大きくすることが考えられるが、これをあまり大きくすると、当然ながら外径も大きくなり、筒体１３の内壁面や遮蔽板１６とのギャップがとれなくなる。このため、場合によっては製作時や運搬時に第１冷媒管１０が変形することが有り、この状態で運転すると第1冷媒管１０が筒体１３の内壁面や遮蔽板１６に当たり異常音の発生や動作不良の原因となる。更に、第１冷媒室１７の断面積から第１冷媒管１０の断面積を引いた第１冷媒室１７の有効断面積が小さくなり、第１冷媒室１７での冷媒流速が上昇し気液分離性能が改善されないこともある。
【００２６】
このため、第１冷媒管１０の断面積（内径が大きくなると噴出速度が下がるが、同時に外径が大きくなり噴出した以降の上昇流速が増速する）及び第１冷媒室１７の断面積と、気液分離性能との間に何らかの関係があるとみてよい。気液分離器をガラスで製作して可視化実験を行った結果、内径４.９５（外径６.３５）の冷媒管と、内径８.１２（外径９.５２）の冷媒管との気液分離状況を比較すると、ＣＯＰを測定する迄もなく明らかに後者の径が広い冷媒管の方が良く分離されていることが確認された。このことから、冷媒管出口流速を決める管径の要素が強く働き、先ず関係（内径）が小さいものは排除されなければならない。なお、暖房の場合には、冷媒の流れが逆転し、第１冷媒管１０と第２冷媒管１１の関係および第１冷媒室１７と第2冷媒室との関係が逆転するだけで、同様な動作を行う。
【００２７】
図４に、ＪＩＳ定格条件で定格冷房能力２．８ｋＷのルームエアコンを用いて、冷房及び暖房の場合に対して、横軸に入口側冷媒室（１７あるいは１８）の断面積と入口側冷媒管（１０あるいは１１）の内断面積の比（Ｒ）を取り、縦軸に冷房及び暖房の場合のＣＯＰ向上率を取ってプロットした図を示す。
【００２８】
図４（図３のと同様の傾向を示す）から、冷房の場合は、断面積比Ｒの広い範囲にわたってＣＯＰを向上でき、気液分離器４をコンパクト化したいことも考慮して、４％以上のＣＯＰ向上率が見込める断面積比Ｒは７から２０位である。但し、断面積比Ｒが約１７．５以上になるとＣＯＰ向上率が低下する傾向を示しているが、これは前述した拡大・縮小損失によるものであると考えられる。
【００２９】
これに対して、暖房の場合、多少なりともＣＯＰの向上が見込めるのは断面積比Ｒが約１０以上の場合であり、１％以上では断面積比Ｒが１１以上、２％以上では１３以上の断面積比Ｒの場合である。従って、暖房においては、断面積比Ｒが１２〜２０位とすると一定のＣＯＰの向上率が見込める。
【００３０】
そして、第１冷媒室１７と第２冷媒室１８の断面積を同一とした場合、冷房、暖房とも高いＣＯＰ向上率を得るには、断面積比Ｒは１２〜２０位の範囲が適切である。なおこの場合、筒体１３の内径を４０〜５５とすると、第１冷媒管１０及び第２冷媒管１１の内径は６．３〜１１．２ｍｍ程度となる。
【００３１】
さらに、第１あるいは第２冷媒室１７、１８内の冷媒流の乱れは、第１あるいは第２冷媒管１０、１１から噴出された冷媒が下フタ１５に衝突する場合にも発生する。この場合、少なくとも冷媒管１７、１８の出口直下およびその周辺において傾斜や変形があると、そのために冷媒流に偏りが生じ流速が速くなり、分離性能が低下する。一方、下フタ１５において冷媒管１０、１１の出口直下およびその周辺が平板の場合には、冷媒が一様に広がることから、冷媒流の偏りが少なくなり流速が下がり気液分離性能が良くなる。
【００３２】
この場合の例を図５（ａ）（ｂ）に示す。図５（ａ）では気液分離器４の下端が逆円錐形になっており、この場合には、冷媒管からの噴出冷媒流が底面に衝突すると、この冷媒流が逆円錐状の斜面により遮蔽板の方に集められることから遮蔽板にそって流れる冷媒流量が増加し、流れの乱れが大きくなる。この結果、気液分離性能が低下し、特に暖房の場合に気液分離状態が悪かった。これに対し図５（ｂ）のように気液分離器底面に底仕切を入れて底面を平面化すると気液分離性能が向上した。従って、気液分離性能を良くするには、気液分離器４における冷媒管１０あるいは１１の出口直下およびその周辺はほぼ平面にすることが望ましい。
【００３３】
また、図２において、第１，第２冷媒管の下端と下フタ１５との距離ａは、気液二相流冷媒が流れ出す上流側の冷媒管では、ａが狭すぎると冷媒管下端で下フタ１５によって流れが阻害されて乱れが増大し、分離性能の低下や圧力損失の増加による冷凍性能の低下が起こる可能性がある。
【００３４】
一方、冷媒を吸い出す下流側の冷媒管の挙動について説明する。冷媒室に液冷媒が溜まっていない状態では、下流側冷媒管はガス冷媒を吸っている。液冷媒が溜まり始め、下流側冷媒管の下端部に到達すると、液冷媒を吸込み始める。このため、液面の上昇はここで止まる。換言すると、冷媒管の下端位置はその冷媒管が下流側（吸い込み側）冷媒管であれば、冷媒室に滞留する液冷媒の液面高さを意味する。
【００３５】
以上のことから、液冷媒のみを吸い出すためには液面高さは下流側冷媒管の先端までなければならないことから、下フタ１５とのギャップａが高ければ高いほど液面を確保するための冷媒が必要であり、その分余分な冷媒が必要となる。従って、このギャップａに関しても最適値があるはずである。本実施の形態では、冷房・暖房において第１，第２冷媒管の役割が逆転することを考慮してギャップａの長さを同じとした場合、筒体１３の径が４０〜５５ｍｍ位では、ａを８ｍｍから１５ｍｍ（採用値は約１０ｍｍ）で良好な結果が得られた。
【００３６】
また遮蔽板１６の高さも最適値が存在すると考えられる。遮蔽板１６の高さｂは気液を分離する上流側の冷媒管側を考えると、液面乱れにより十分な気液分離ができず下流側冷媒管にガス冷媒が混入するのを防止するには、ｂは高いほうがよい。しかし、冷媒を吸い出す側の下流側冷媒管を考えると、遮蔽板１６の上端から冷媒が落下してくることになり、ｂが大きく液面と遮蔽板１６の上端との距離が大きいほど落下してくる冷媒による撹拌作用が増し、下流側冷媒管より吸い出す冷媒に気体が混合される可能性が高くなり分離性能が低下することになる。
【００３７】
したがって、下流側冷媒管の下端と遮蔽板１６の上端との差（重なり部分：ｂ−ａ）としては、筒体１３の内径が４０〜５５ｍｍの時、７ｍｍから１５ｍｍ（採用値は約１０ｍｍ）で良好な結果が得られる。
【００３８】
ここで、以上に述べた各部の適正仕様を盛り込んだ気液分離器の概略構造と空気調和機としての性能向上を図５（ｃ）（ｄ）に示し、気液分離器の仕様を適正にすればＣＯＰを大きく向上できることがわかる。
【００３９】
すなわち、（ｃ）においては、筒体内径を３６ｍｍから５５ｍｍの範囲内の４８．６ｍｍとし、断面積比Ｒを１１から２０の範囲の約１３．０とし、接続管内径を８．１２ｍｍとし、底面と接続管先端との距離を８ｍｍから１５ｍｍの範囲内の１０ｍｍとし、接続管下端と遮蔽板の上端との差を７ｍｍから１５ｍｍの範囲内の１０ｍｍとし、下フタ形状を平板とした時、目視による気液分離性能は冷房及び暖房において良好になされ、この結果ＣＯＰは冷房時４.７％、暖房時２.１％それぞれ向上した。
【００４０】
また、（ｄ）においては、筒体内径を３６ｍｍから５５ｍｍの範囲内の４５．４ｍｍとし、断面積比Ｒを１１から２０の範囲の約１１．４とし、接続管内径を８．１２ｍｍとし、底面と接続管先端との距離を８ｍｍから１５ｍｍの範囲内の１０ｍｍとし、接続管下端と遮蔽板の上端との差を７ｍｍから１５ｍｍの範囲内の１０ｍｍとし、下フタ形状を平板とした時、目視による気液分離性能は冷房及び暖房において良好になされ、この結果ＣＯＰは冷房時４.９％、暖房時１.７％それぞれ向上した。
【００４１】
なお、これまでに述べた動作・効果は、定格冷房能力が更に大きな４〜５ｋＷの空気調和機においても十分得られており、例えば、定格冷房能力４ｋＷの空気調和機で、図５（ｄ）の仕様の気液分離器を用いた場合、気液分離状態は良好で、冷房定格運転で７〜８％、暖房定格運転で３〜４％の高いＣＯＰ向上率が得られた。従って、上記で述べた気液分離器の寸法及び形状の仕様は、少なくとも家庭用あるいは業務用程度の容量の空気調和機に対して適用でき、十分なＣＯＰ向上効果を得ることができる。
【００４２】
【発明の効果】
以上本発明によれば、気液分離精度がよい形状や寸法を気液分離器を備えた空気調和機を提供することができる。
【図面の簡単な説明】
【図１】本発明による気液分離器の実施の形態を用いるガスインジェクション冷凍サイクルの基本的構成を示す。
【図２】本発明による気液分離器の基本構造を示す。
【図３】本発明における気液分離器の筒体径とＣＯＰ向上効果の関係を示す。
【図４】本発明における気液分離器の冷媒室断面積と冷媒管内断面積の比に対するＣＯＰ向上効果の関係を示す
【図５】本発明において検討したいくつかの気液分離器の構造と性能の関係を示す。
【符号の説明】
１…圧縮機、２…第１熱交換器、３…第１減圧器（電動膨張弁）、４…気液分離器、５…第２減圧器（電動膨張弁）、６…第２熱交換器、７…流量調整弁、８…四方弁、９…インジェクションポート、１０…第１冷媒管、１１…第２冷媒管、１２…第３冷媒管、１３…筒体、１４…上フタ、１５…下フタ、１６…遮蔽板、１７…第１冷媒室、１８…第２冷媒室、２０…筒状の本体。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner using a refrigerant such as R22, R407C, or R410A, etc., and providing a gas-liquid separator to form a refrigeration cycle capable of gas injection.
[0002]
[Prior art]
Compressor, four-way valve, outdoor heat exchanger that functions as a condenser during heating and an evaporator during heating, first decompressor, gas-liquid separator, second decompressor, condenser during heating and evaporator during cooling A refrigeration cycle having a so-called gas injection circuit for injecting gas refrigerant separated by a gas-liquid separator into an intermediate pressure stage of a compressor is used as a refrigeration cycle in which functioning indoor heat exchangers are sequentially connected by piping. (Microfilm of Japanese Utility Model Application No. Sho 62-183746, hereinafter referred to as literature).
[0003]
In the gas-liquid separator described in this document, the first refrigerant pipe and the second refrigerant pipe respectively connected to the decompression device are divided into two spaces partitioned by a shielding plate erected from the bottom surface of the cylindrical container. Each is inserted from the side of the container, and each tip is bent toward the bottom. Then, the gas-liquid two-phase refrigerant flowing from one refrigerant pipe collides with the bottom surface of the cylindrical container and rises in the space formed by the inner surface of the container and the side surface of the shielding plate, and the other refrigerant pipe is inserted into the liquid refrigerant. The gas refrigerant is guided to a pipe constituting a gas injection circuit inserted in the upper part of the container into the adjacent space, whereby the two-phase refrigerant is separated into gas and liquid.
[0004]
[Problems to be solved by the invention]
By the way, this document describes the structure of a gas-liquid separator, but does not discuss the shape and dimensions of the gas-liquid separator. There is a problem that the refrigerant flowing into the liquid storage chamber space flows out of the downstream refrigerant pipe as it is.
[0005]
The objective of this invention is providing the shape and dimension of a gas-liquid separator with the sufficient gas-liquid separation precision of a refrigerant | coolant.
[0006]
[Means for Solving the Problems]
The purpose is to provide a refrigeration cycle in which a compressor, a first heat exchanger on the heat source side, a first pressure reducer, a gas-liquid separator, a second pressure reducer, and a second heat exchanger on the usage side are sequentially connected by piping. And an air conditioner having an injection circuit for connecting the gas-liquid separator and the compressor by piping, the gas-liquid separator is provided with a shielding plate on the bottom surface of the cylindrical container, and the first pressure reducer The first refrigerant pipe connected to the second refrigerant pipe and the second refrigerant pipe connected to the second pressure reducer are inserted into a space where the lower ends of the refrigerant pipes are surrounded by the shielding plate and the inner wall surface of the gas-liquid separator, and the injection is performed. A third refrigerant pipe connected to the circuit is inserted into the upper part of the gas-liquid separator, and the distance from the upper end of the shielding plate to the lower end of the refrigerant pipe is in the range of 7 mm to 15 mm. To be achieved.
[0007]
Furthermore, the said objective connected the compressor, the 1st heat exchanger by the side of a heat source, the 1st decompressor, the gas-liquid separator, the 2nd decompressor, and the 2nd heat exchanger by the side of use in order by piping. In an air conditioner including a refrigeration cycle and an injection circuit for connecting the gas-liquid separator and the compressor by piping, the gas-liquid separator is provided with a shielding plate on a bottom surface of a cylindrical container, and the first Inserting the first refrigerant pipe connected to the pressure reducer and the second refrigerant pipe connected to the second pressure reducer to a space where the lower ends of these refrigerant pipes are surrounded by the shielding plate and the inner wall surface of the gas-liquid separator; A third refrigerant pipe connected to the injection circuit is inserted into the upper part of the gas-liquid separator, the bottom surface of the cylindrical container is planar, and the inner diameter of the cylindrical container is in the range of 36 mm to 55 mm. The cylinder from the lower end of the first and second refrigerant tubes The distance to the inner bottom surface of the container to be in the range of 15mm from 8 mm, is achieved by such the range distance from 7mm to 15mm from the upper end of the shielding plate to the lower end of the refrigerant pipe.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a refrigeration cycle capable of gas injection using a gas-liquid separator according to the present embodiment. Injectable compressor 1 (reciprocator with injection port, rotary, scroll compressor, two-stage compressor as in the literature, etc.), four-way valve 8 that changes the refrigerant flow direction of the cycle and switches between cooling and heating, heat source The first heat exchanger 2 on the side, the first pressure reducer in the present embodiment, the electric expansion valve 3, the gas-liquid separator 4, the second pressure reducer in the present embodiment on the electric expansion valve 5, the second on the use side. The heat exchanger 6 is sequentially connected by piping to constitute a refrigeration cycle, and the injection gas is taken into the compression chamber 1 through the flow rate adjusting valve 7 that controls the injection amount from the gas-liquid separator 4 to the compressor 1. A gas injection circuit is formed by connecting to the injection port 9 by piping.
[0010]
Next, FIG. 2 shows an embodiment of the gas-liquid separator 4. A cylindrical main body (container) 20 is provided with a refrigerant pipe for connection to the refrigeration cycle of FIG. The cylindrical main body 20 is formed of a cylindrical body 13, an upper lid 14, and a lower lid 15 that constitute an annular container side surface. The lower space in the container is partitioned into a first refrigerant chamber 17 and a second refrigerant chamber 18 by the shielding plate 16 being erected from the container bottom surface (the inner surface of the lower lid 15). The first refrigerant pipe 10 connected to the first pressure reducer 3 and the second refrigerant pipe 11 connected to the second pressure reducer 5 have tips in the first refrigerant chamber 17 and the second refrigerant chamber 18, respectively. And inserted from the upper lid 14. The third refrigerant pipe 12 connected to the flow control valve 7 is inserted from the inner surface of the upper lid 14 to a position where it slightly protrudes into the cylinder upper body 20.
[0011]
Further, as shown in the drawing, the height from the inner surface of the lower cover 15 of the shielding plate 16 provided between the first refrigerant pipe 10 and the second refrigerant pipe 11 is b, and the first and second refrigerant pipes 10, 11 are arranged. A gap of a length a is opened from the inner surface of the lower lid 15.
[0012]
In the refrigeration cycle described above, the operation during the cooling operation will be described next. In FIG. 1, the flow direction of the refrigerant during cooling is indicated by broken line arrows. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 reaches the first heat exchanger 2 serving as a condenser via the four-way valve 8. The low-temperature and high-pressure liquid refrigerant condensed by the first heat exchanger 2 is reduced to an intermediate pressure between the suction pressure and the discharge pressure of the compressor 1 by the first pressure reducer 3 and becomes a gas-liquid two-phase flow. The gas enters the gas-liquid separator 4 through the first refrigerant pipe 10.
[0013]
The refrigerant that has passed through the first refrigerant pipe 10 collides with the lower lid 15 and rises along a space (first refrigerant chamber 17) formed by the shielding plate 16 and the cylindrical body 13. In this ascending process, the refrigerant is separated into a gas refrigerant having a small specific gravity and a liquid refrigerant having a large specific gravity. The gas refrigerant is diffused into the cylindrical body 13 against gravity, enters the upper third refrigerant pipe 12, and is injected into the compressor 1 from the injection port 9 through the open flow control valve 7. .
[0014]
On the other hand, the liquid refrigerant remaining in the first refrigerant chamber 17 gets over the shielding plate 16 and flows into the space (second refrigerant chamber 18) formed by the shielding plate and the cylinder on the second refrigerant tube side. 2 accumulates in the refrigerant chamber 18, further passes through the second refrigerant pipe 11 to the second pressure reducing valve 5, flows into the second heat exchanger 6 that becomes an evaporator after being depressurized, and exchanges heat with indoor air. As a result, it evaporates into a high-temperature and low-pressure gas refrigerant and reaches the intake pipe of the compressor through the four-way valve 8.
[0015]
When the liquid level of the refrigerant accumulated in the second refrigerant chamber 18 is higher than the lower end of the second refrigerant pipe 11 and does not contain gas refrigerant, only the liquid refrigerant flows out from the second refrigerant pipe 11. As a result of such an operation, gas-liquid separation can be achieved by flowing the gas refrigerant in the gas-liquid two-phase flow that has entered from the first refrigerant pipe 10 to the third refrigerant pipe 12 and the liquid refrigerant to the second refrigerant pipe 11. it can.
[0016]
In the case of this cooling cycle, in order to improve the gas-liquid separation, it is important to prevent the gas refrigerant from being mixed into the refrigerant accumulated in the second refrigerant chamber 18. For this purpose, it is necessary to suppress the disturbance of the refrigerant accumulated in the first refrigerant chamber 17 and the second refrigerant chamber 18 as much as possible. The most effective method for this is to increase the cross-sectional area in the cylindrical body 13 and This is to reduce the refrigerant flow rate in the second refrigerant chambers 17 and 18. Here, in particular, when the cross-sectional area of the first refrigerant chamber 17 is increased, the flow velocity of the refrigerant that has come out of the first refrigerant pipe 10 is reduced, and gas-liquid separation is facilitated due to the density difference between the gas phase and the liquid phase. However, increasing the cross-sectional area means increasing the diameter of the cylinder 13, and the gas-liquid separator 4 becomes larger. As a result, the space occupied by the gas-liquid separator in the machine room that houses the refrigeration cycle becomes large, and as a result, the entire outdoor unit becomes large.
[0017]
Therefore, it is necessary for the gas-liquid separator to suppress the diameter of the cylinder as much as possible while ensuring sufficient gas-liquid separation performance.
[0018]
In the case of heating, the refrigerant flow is reversed, and the relationship between the first refrigerant tube 10 and the second refrigerant tube 11 and the relationship between the first refrigerant chamber 17 and the second refrigerant chamber 18 are reversed. For this reason, since the second refrigerant chamber 18 serves as a refrigerant inlet space, it is necessary to increase the cross-sectional area in order to reduce the flow velocity. In addition, only the flow of the refrigerant is reversed between the cooling and the heating, and the behavior of the refrigerant is the same as that of the cooling.
[0019]
By the way, since the pressure inside the container of the gas-liquid separator 4 becomes a high pressure of 20 kg / cm 2 or more, it must be a pressure container. As the pressure vessel, a spherical shape is the best. However, since it is difficult and expensive to manufacture, it is a cylindrical shape like a closed vessel such as a scroll compressor or a rotary compressor. As described above, since the shielding plate 16 is disposed on the bottom surface of the gas-liquid separator 4, when the shielding plate is placed at a position passing through the center of the lower lid 15, the first refrigerant chamber 17 and the second refrigerant chamber 18. Both have a semicircular cross section. Since the refrigerant pipe is inserted into such a refrigerant chamber, when the refrigerant colliding with the inner surface of the lower lid 17 rises, the flow velocity increases in a narrow part such as between the shielding plate 16 and the refrigerant pipe, and in a wide part. The flow rate becomes slow. For this reason, if the inner diameter of the gas-liquid separator is changed without changing the diameter of the refrigerant tube, some optimum condition should be found from the aspect of gas-liquid separation performance.
[0020]
As an example, FIG. 3 shows an improvement in performance by gas injection of cooling and heating when the inner diameter of the cylinder 13 of the gas-liquid separator 4 is changed using a room air conditioner having a rated cooling capacity of 2.8 kW under JIS rated conditions. The measurement results are plotted with the horizontal axis indicating the inner diameter of the cylinder 13 and the vertical axis indicating the COP (capacity / input) improvement rate of the room air conditioner. The shielding plate 16 has a thickness of 0.5 mm to 0.8 mm, and the inserted refrigerant pipe has an outer diameter of 9.52 mm.
[0021]
From this figure, it is possible to improve the COP over a wide range of the inner diameter of the cylinder 13 in the case of cooling, but in the case of heating, the COP is lowered when the inner diameter of the cylinder 13 is about 36 mm or less. Thus, in order to improve COP in both the cooling and heating cases, the inner diameter of the cylinder 13 needs to be about 36 mm or more. Further, when the inner diameter of the cylindrical body 13 is about 40 mm to 55 mm, the improvement rate of the COP is not so changed in both the cooling and heating, and a high value is obtained.
[0022]
However, in the case of cooling, the COP improvement rate tends to decrease from the inner diameter of the cylinder 13 of about 49 mm. This is because the ratio of the gas in the two-phase flow flowing into the gas-liquid separator 4 is larger in the cooling than in the heating, and the gaseous refrigerant passes through the cylindrical body 13 where the inner diameter suddenly increases from the thin refrigerant pipe 10. It expands and is sucked into the third refrigerant pipe 12 having a small inner diameter. The reason why the COP improvement rate decreases when the inner diameter of the cylindrical body 13 is excessively increased is that the expansion loss when the refrigerant flows out from the first connecting pipe 10 into the cylindrical main body 20, or the cylindrical main body 20. This is considered to be related to an increase in the reduction loss when flowing into the third connecting pipe 12 from the second connecting pipe 12. On the other hand, in heating, since the ratio of gas is small, the flow rate is reduced, and the inner diameter of the cylindrical body 13 is increased, the separation rate is improved. Therefore, there is no tendency to decrease at the inner diameter level where the COP improvement rate decreases during cooling.
[0023]
Therefore, the factors that determine the inner diameter of the cylinder 13 are based on the idea that the lower limit of the inner diameter is determined by the COP improvement rate during heating, and the upper limit of the inner diameter is determined by the COP improvement rate during cooling.
[0024]
From the fact that the gas-liquid separator 4 described above is desired to be as compact as possible and the result of FIG. 4, the inner diameter of the cylinder 13 needs to be about 35 to 55 mm in order to obtain the COP improvement effect. In order to obtain a high COP improvement rate for both cooling and heating, a range of about 40 to 55 mm is most appropriate.
[0025]
The cause of the disturbance of the refrigerant flow in the refrigerant chamber is considered to be the flow speed when the refrigerant is ejected from the first refrigerant pipe 10 to the first refrigerant chamber 17 in the case of cooling. In order to reduce the jetting speed of the refrigerant, it is conceivable to increase the inner diameter of the first refrigerant pipe 10. However, if the inner diameter of the first refrigerant pipe 10 is increased too much, the outer diameter naturally increases, and the inner wall surface of the cylindrical body 13 and the shielding plate 16. The gap with can not be taken. Therefore, in some cases, the first refrigerant pipe 10 may be deformed at the time of production or transportation, and when operated in this state, the first refrigerant pipe 10 hits the inner wall surface of the cylindrical body 13 or the shielding plate 16 to generate abnormal noise, It may cause malfunction. Furthermore, the effective cross-sectional area of the first refrigerant chamber 17 obtained by subtracting the cross-sectional area of the first refrigerant tube 10 from the cross-sectional area of the first refrigerant chamber 17 becomes smaller, the refrigerant flow rate in the first refrigerant chamber 17 increases, and gas-liquid separation occurs. Performance may not be improved.
[0026]
For this reason, the cross-sectional area of the first refrigerant tube 10 (when the inner diameter increases, the ejection speed decreases, but at the same time the outer diameter increases and the rising flow rate increases after ejection), and the cross-sectional area of the first refrigerant chamber 17; It may be considered that there is some relationship between gas-liquid separation performance. As a result of visualizing the gas-liquid separator made of glass, it was found that the gas between the refrigerant tube having an inner diameter of 4.95 (outer diameter 6.35) and the refrigerant tube having an inner diameter of 8.12 (outer diameter 9.52) was obtained. Comparing the liquid separation situation, it was confirmed that the refrigerant pipe having the larger diameter obviously was better separated without measuring COP. For this reason, the element of the pipe diameter that determines the refrigerant pipe outlet flow velocity works strongly, and first, the one having a small relationship (inner diameter) must be excluded. In the case of heating, the flow of the refrigerant is reversed, and only the relationship between the first refrigerant tube 10 and the second refrigerant tube 11 and the relationship between the first refrigerant chamber 17 and the second refrigerant chamber is reversed. Perform the action.
[0027]
FIG. 4 shows the cross-sectional area of the inlet side refrigerant chamber (17 or 18) and the inlet side refrigerant pipe on the horizontal axis in the case of cooling and heating using a room air conditioner with a rated cooling capacity of 2.8 kW under the JIS rated conditions. The figure which took the ratio (R) of the inner cross-sectional area of (10 or 11), and took and plotted the COP improvement rate in the case of cooling and heating on the vertical axis is shown.
[0028]
From FIG. 4 (showing the same tendency as in FIG. 3), in the case of cooling, the COP can be improved over a wide range of the cross-sectional area ratio R, and considering that the gas-liquid separator 4 is desired to be compact, 4% The cross-sectional area ratio R in which the above COP improvement rate can be expected is 7th to 20th. However, when the cross-sectional area ratio R is about 17.5 or more, the COP improvement rate tends to decrease, which is considered to be due to the above-described expansion / reduction loss.
[0029]
On the other hand, in the case of heating, the COP can be expected to improve somewhat when the cross-sectional area ratio R is about 10 or higher. When the cross-sectional area ratio R is 1% or higher, the cross-sectional area ratio R is 11 or higher. This is the case of the cross-sectional area ratio R. Therefore, in heating, a constant COP improvement rate can be expected when the cross-sectional area ratio R is about 12-20.
[0030]
And when the cross-sectional area of the 1st refrigerant | coolant chamber 17 and the 2nd refrigerant | coolant chamber 18 is made the same, in order to obtain a high COP improvement rate for both air_conditioning | cooling and heating, the range of 12-20 rank is suitable for cross-sectional area ratio R. . In this case, when the inner diameter of the cylinder 13 is 40 to 55, the inner diameters of the first refrigerant pipe 10 and the second refrigerant pipe 11 are about 6.3 to 11.2 mm.
[0031]
Further, the turbulence of the refrigerant flow in the first or second refrigerant chambers 17 and 18 also occurs when the refrigerant ejected from the first or second refrigerant pipes 10 and 11 collides with the lower lid 15. In this case, if there is an inclination or deformation at least directly under the outlets of the refrigerant pipes 17 and 18 and in the vicinity thereof, the refrigerant flow is biased to increase the flow velocity and lower the separation performance. On the other hand, when the lower lid 15 has a flat plate directly below and around the outlets of the refrigerant tubes 10 and 11, the refrigerant spreads uniformly, so that the deviation of the refrigerant flow is reduced, the flow velocity is reduced, and the gas-liquid separation performance is improved. .
[0032]
An example of this case is shown in FIGS. In FIG. 5A, the lower end of the gas-liquid separator 4 has an inverted conical shape. In this case, when the refrigerant flow ejected from the refrigerant pipe collides with the bottom surface, the refrigerant flow is caused by the inverted conical slope. Since the refrigerant is collected toward the shielding plate, the flow rate of the refrigerant flowing along the shielding plate increases, and the turbulence of the flow increases. As a result, the gas-liquid separation performance was lowered, and the gas-liquid separation state was poor particularly in the case of heating. On the other hand, as shown in FIG. 5B, when a bottom partition is placed on the bottom surface of the gas-liquid separator and the bottom surface is planarized, the gas-liquid separation performance is improved. Therefore, in order to improve the gas-liquid separation performance, it is desirable that the portion immediately below the outlet of the refrigerant pipe 10 or 11 in the gas-liquid separator 4 and its periphery be substantially flat.
[0033]
In FIG. 2, the distance a between the lower ends of the first and second refrigerant pipes and the lower lid 15 is lower at the lower end of the refrigerant pipe when a is too narrow in the upstream refrigerant pipe from which the gas-liquid two-phase refrigerant flows. The flow is obstructed by the lid 15 and the turbulence increases, which may cause a decrease in separation performance and a decrease in refrigeration performance due to an increase in pressure loss.
[0034]
On the other hand, the behavior of the downstream refrigerant pipe that sucks out the refrigerant will be described. In a state where liquid refrigerant is not accumulated in the refrigerant chamber, the downstream refrigerant pipe sucks gas refrigerant. When the liquid refrigerant starts to accumulate and reaches the lower end of the downstream refrigerant pipe, the liquid refrigerant starts to be sucked. For this reason, the rise of the liquid level stops here. In other words, the lower end position of the refrigerant pipe means the liquid level height of the liquid refrigerant staying in the refrigerant chamber if the refrigerant pipe is a downstream (suction side) refrigerant pipe.
[0035]
From the above, in order to suck out only the liquid refrigerant, the liquid level must reach the tip of the downstream refrigerant pipe, so that the higher the gap a with the lower lid 15, the higher the liquid level. A refrigerant is required, and an extra refrigerant is required. Therefore, there should be an optimum value for the gap a. In the present embodiment, when the length of the gap a is the same considering that the roles of the first and second refrigerant tubes are reversed in cooling / heating, the diameter of the cylinder 13 is about 40 to 55 mm. Good results were obtained when a was 8 to 15 mm (adopted value was about 10 mm).
[0036]
It is also considered that there is an optimum value for the height of the shielding plate 16. The height b of the shielding plate 16 is considered to prevent the gas refrigerant from being mixed into the downstream refrigerant pipe because sufficient gas-liquid separation cannot be performed due to the liquid level disturbance considering the upstream refrigerant pipe side separating the gas and liquid. B should be higher. However, when considering the downstream refrigerant pipe on the side of sucking out the refrigerant, the refrigerant falls from the upper end of the shielding plate 16 and falls as the distance between the liquid level and the upper end of the shielding plate 16 increases. The agitation action by the incoming refrigerant increases, and there is a high possibility that gas will be mixed with the refrigerant sucked out from the downstream refrigerant pipe, resulting in a decrease in separation performance.
[0037]
Therefore, the difference between the lower end of the downstream refrigerant pipe and the upper end of the shielding plate 16 (overlapping portion: ba) is 7 mm to 15 mm when the inner diameter of the cylinder 13 is 40 to 55 mm (adopted value is about 10 mm). Gives good results.
[0038]
Here, the schematic structure of the gas-liquid separator incorporating the appropriate specifications of each part described above and the performance improvement as an air conditioner are shown in FIGS. 5C and 5D, and the specifications of the gas-liquid separator are appropriately set. It can be seen that the COP can be greatly improved.
[0039]
That is, in (c), the cylinder inner diameter is 48.6 mm in the range of 36 mm to 55 mm, the cross-sectional area ratio R is about 13.0 in the range of 11 to 20, the connection pipe inner diameter is 8.12 mm, When the distance between the bottom surface and the tip of the connecting tube is 10 mm within the range of 8 mm to 15 mm, the difference between the lower end of the connecting tube and the upper end of the shielding plate is 10 mm within the range of 7 mm to 15 mm, and the lower lid shape is a flat plate, The gas-liquid separation performance by visual inspection was good in cooling and heating, and as a result, COP was improved by 4.7% during cooling and by 2.1% during heating.
[0040]
In (d), the cylinder inner diameter is 45.4 mm in the range of 36 mm to 55 mm, the cross-sectional area ratio R is about 11.4 in the range of 11 to 20, the connecting pipe inner diameter is 8.12 mm, When the distance between the bottom surface and the tip of the connecting tube is 10 mm within the range of 8 mm to 15 mm, the difference between the lower end of the connecting tube and the upper end of the shielding plate is 10 mm within the range of 7 mm to 15 mm, and the lower lid shape is a flat plate, The gas-liquid separation performance by visual inspection was good in cooling and heating. As a result, COP was improved by 4.9% during cooling and 1.7% during heating.
[0041]
The operations and effects described so far are sufficiently obtained even in a 4 to 5 kW air conditioner having a larger rated cooling capacity. For example, in an air conditioner having a rated cooling capacity of 4 kW, FIG. When the gas-liquid separator of the specifications was used, the gas-liquid separation state was good, and a high COP improvement rate of 7 to 8% in the cooling rated operation and 3 to 4% in the heating rated operation was obtained. Therefore, the size and shape specifications of the gas-liquid separator described above can be applied to an air conditioner having a capacity of at least a household or business use, and a sufficient COP improvement effect can be obtained.
[0042]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an air conditioner including a gas-liquid separator having a shape and size with good gas-liquid separation accuracy.
[Brief description of the drawings]
FIG. 1 shows a basic configuration of a gas injection refrigeration cycle using an embodiment of a gas-liquid separator according to the present invention.
FIG. 2 shows the basic structure of a gas-liquid separator according to the present invention.
FIG. 3 shows the relationship between the cylinder diameter of the gas-liquid separator and the COP improvement effect in the present invention.
FIG. 4 shows the relationship of COP improvement effect to the ratio of the refrigerant chamber cross-sectional area and the refrigerant pipe cross-sectional area of the gas-liquid separator in the present invention. FIG. 5 shows the structures of several gas-liquid separators examined in the present invention. The relationship of performance is shown.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... 1st heat exchanger, 3 ... 1st decompressor (electric expansion valve), 4 ... Gas-liquid separator, 5 ... 2nd decompressor (electric expansion valve), 6 ... 2nd heat exchange 7 ... Flow rate adjusting valve, 8 ... Four-way valve, 9 ... Injection port, 10 ... First refrigerant pipe, 11 ... Second refrigerant pipe, 12 ... Third refrigerant pipe, 13 ... Cylindrical body, 14 ... Upper lid, 15 ... lower cover, 16 ... shielding plate, 17 ... first refrigerant chamber, 18 ... second refrigerant chamber, 20 ... cylindrical main body.

Claims

圧縮機、熱源側となる第１熱交換器、第１減圧器、気液分離器、第２減圧器、利用側となる第２熱交換器とを順次配管で接続した冷凍サイクルと、この気液分離器と前記圧縮機とを配管によって接続するインジェクション回路とを備えた空気調和機において、前記気液分離器を、筒状容器底面に遮蔽板を設け、前記第１減圧器に接続された第１冷媒管及び前記第２減圧器に接続された第２冷媒管をこれら冷媒管下端が前記遮蔽板と気液分離器の容器内壁面によって囲まれる空間まで挿入し、前記インジェクション回路に接続される第３の冷媒管を前記気液分離器上部に挿入して構成し、前記遮蔽板の上端から前記冷媒管の下端までの距離を７ｍｍから１５ｍｍの範囲になるようにした空気調和機。 A refrigeration cycle in which a compressor, a first heat exchanger on the heat source side, a first pressure reducer, a gas-liquid separator, a second pressure reducer, and a second heat exchanger on the usage side are sequentially connected by piping, In an air conditioner including an injection circuit for connecting a liquid separator and the compressor by piping, the gas-liquid separator is provided with a shielding plate on a bottom surface of a cylindrical container, and connected to the first decompressor. The second refrigerant pipe connected to the first refrigerant pipe and the second pressure reducer is inserted into a space surrounded by the shielding plate and the inner wall surface of the gas-liquid separator container, and connected to the injection circuit. An air conditioner in which a third refrigerant pipe is inserted into the upper part of the gas-liquid separator so that the distance from the upper end of the shielding plate to the lower end of the refrigerant pipe is in the range of 7 mm to 15 mm.

圧縮機、熱源側となる第１熱交換器、第１減圧器、気液分離器、第２減圧器、利用側となる第２熱交換器とを順次配管で接続した冷凍サイクルと、この気液分離器と前記圧縮機とを配管によって接続するインジェクション回路とを備えた空気調和機において、前記気液分離器を、筒状容器底面に遮蔽板を設け、前記第１減圧器に接続された第１冷媒管及び前記第２減圧器に接続された第２冷媒管をこれら冷媒管下端が前記遮蔽板と気液分離器の容器内壁面によって囲まれる空間まで挿入し、前記インジェクション回路に接続される第３の冷媒管を前記気液分離器上部に挿入して構成し、前記筒状容器の底面を平面状にし、前記筒状容器の内径を３６ｍｍから５５ｍｍの範囲にし、前記第１及び第２の冷媒管の下端から筒状容器の内底面までの距離を８ｍｍから１５ｍｍの範囲になるようにし、前記遮蔽板の上端から前記冷媒管の下端までの距離を７ｍｍから１５ｍｍの範囲になるようにした空気調和機。 A refrigeration cycle in which a compressor, a first heat exchanger on the heat source side, a first pressure reducer, a gas-liquid separator, a second pressure reducer, and a second heat exchanger on the usage side are sequentially connected by piping, In an air conditioner including an injection circuit for connecting a liquid separator and the compressor by piping, the gas-liquid separator is provided with a shielding plate on a bottom surface of a cylindrical container, and connected to the first decompressor. The second refrigerant pipe connected to the first refrigerant pipe and the second pressure reducer is inserted into a space surrounded by the shielding plate and the inner wall surface of the gas-liquid separator container, and connected to the injection circuit. A third refrigerant pipe is inserted into the upper part of the gas-liquid separator, the bottom surface of the cylindrical container is planar, the inner diameter of the cylindrical container is in the range of 36 mm to 55 mm, and the first and first 2 from the lower end of the refrigerant pipe to the inner bottom surface of the cylindrical container A release to be in the range of 15mm from 8 mm, the air conditioner was set to the range of 15mm the distance to the lower end of the refrigerant pipe from 7mm from the upper end of the shielding plate.