JP2004028370A

JP2004028370A - Refrigerator-freezer

Info

Publication number: JP2004028370A
Application number: JP2002181572A
Authority: JP
Inventors: Akihiro Noguchi; 野口　明裕; Takashi Doi; 土井　隆司; Koji Kashima; 鹿島　弘次
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2002-06-21
Filing date: 2002-06-21
Publication date: 2004-01-29

Abstract

<P>PROBLEM TO BE SOLVED: To make coolant flow selecting both at the same time or either one of an evaporator for a refrigerating chamber and an evaporator for a freezing chamber. <P>SOLUTION: In this refrigerator-freezer comprising a freezing cycle running through the evaporator 17 for the refrigerating chamber and the evaporator 25 for the freezing chamber, the coolant is made flow selecting, by a switch means 11, both at the same time or either one of the evaporator 17 for the refrigerating chamber and the evaporator 25 for the freezing chamber. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、冷蔵室用冷凍サイクルと冷凍室用冷凍サイクルを備えた冷凍冷蔵庫に関する。
【０００２】
【従来の技術】
近年の冷凍冷蔵庫は、冷蔵室を始めとして専用の野菜室、冷凍室を備えるようになっている。冷凍室は、冷蔵室・野菜室に比べて一段と低い庫内温度が求められるため、冷蔵室・野菜室は冷蔵室用冷凍サイクルによる温度設定領域で、冷凍室は冷凍室用冷凍サイクルによる温度設定領域でそれぞれ独立した温度管理が行なわれるようになっている。
【０００３】
【発明が解決しようとする課題】
冷蔵室用冷凍サイクルと冷凍室用冷凍サイクルを構成する圧縮機は、２段圧縮機となっていて、低圧側吸込口からの冷媒を中間圧まで加圧する機能と、中間圧まで加圧した冷媒と中間圧側吸込口からの冷媒とを合流、混合し高圧まで加圧し、吐出口から吐出する機能を備えている。
【０００４】
したがって、冷凍室用冷凍サイクルは、２段圧縮機の吐出口から吐出された冷媒が、凝縮器、キャピラリチューブ、冷凍室用蒸発器を通り、再び２段圧縮機の低圧側吸込口へ戻ることで、連続した冷凍室の庫内冷却が得られる。
【０００５】
冷蔵室用冷凍サイクルは、２段圧縮機の吐出口から吐出された冷媒が、凝縮器、キャピラリチューブ、冷蔵室用蒸発器を通り、再び、２段圧縮機の中間圧側吸込口へ戻ることで、連続した冷蔵室の庫内冷却が得られるようになっている。
【０００６】
この場合、冷凍室は冷凍室用ファンの回転数によって、ある程度の庫内温度の温度幅の制御が可能となる。同様に冷蔵室も、冷蔵室用ファンの回転数によって、ある程度の庫内温度の温度幅の制御が可能となるが、例えば、食料品を新たに詰め込む等の条件によって、冷凍室又は冷蔵室のいずれか一方の庫内負荷が大きく異なった時、ファンの回転数による制御では対応できず、一方の庫内では冷却不足が、他方の庫内では冷えすぎとなる不具合を招く。
【０００７】
そこで、この発明は、各庫内負荷が大きく異なった場合でも、冷却不足、あるいは、冷えすぎを起こすことのない冷凍冷蔵庫を提供することを目的としている。
【０００８】
【課題を解決するための手段】
前記目的を達成するために、この発明の請求項１にあっては、低圧側吸込口からの冷媒を中間圧まで加圧した冷媒と中間圧側吸込口からの冷媒と合流、混合し高圧まで加圧する２段圧縮機を有し、２段圧縮機から吐出された冷媒が少なくとも凝縮器、冷蔵室用蒸発器、冷凍室用蒸発器を通る冷凍サイクルを備えた冷凍冷蔵庫において、
前記冷蔵室用蒸発器と冷凍室用蒸発器両方同時に冷媒を流す回路と、冷蔵室用蒸発器又は冷凍室用蒸発器のいずれか一方を選択して冷媒を流す回路に切換制御する切換手段を備えていることを特徴とする。
【０００９】
これにより、切換手段による切換制御によって、例えば、冷蔵室用蒸発器と冷凍室用蒸発器の両方を通る冷凍サイクルにより、それぞれ連続する冷蔵室の庫内冷却と冷凍室の庫内冷却が行なえるようになる。
【００１０】
次に、例えば、冷凍食品を入れることで冷凍室の庫内負荷が大となる一方、冷蔵室の庫内負荷が小の場合には、切換手段による切換制御によって、冷凍室用蒸発器のみ冷媒が流れるよう切換制御する。この結果、冷凍室の庫内負荷に対応した庫内温度が得られるようになり、冷却不足を招くことはない。
【００１１】
一方、冷蔵室用蒸発器にあっては、庫内負荷が小さいため、冷媒が流れなくても庫内冷却に何等支障は起きない。この場合、この時間を利用して、例えば、ファンを回転させることで、冷蔵室用蒸発器の除霜運転が可能となる。
【００１２】
また、切換手段による切換制御によって、例えば、冷蔵室用蒸発器のみ冷媒が流れるよう切換制御することで、冷蔵室の庫内負荷に対応する庫内温度が得られるようになる。
【００１３】
また、この発明の請求項２にあっては、低圧側吸込口からの冷媒を中間圧まで加圧した冷媒と中間圧側吸込口からの冷媒と合流、混合し高圧まで加圧する２段圧縮機を有し、２段圧縮機から吐出された冷媒が少なくとも凝縮器、自然対流式冷蔵室用蒸発器、強制対流式冷蔵室用蒸発器、冷凍室用蒸発器を通る冷凍サイクルを備えた冷凍冷蔵庫において、
前記自然対流式冷蔵室用蒸発器と強制対流式冷蔵室用蒸発器は、切換手段により両方同時に、又は、一方の強制対流式冷蔵室用蒸発器のみ冷媒が流れるよう切換制御可能となっていることを特徴とする。
【００１４】
これにより、例えば、自然対流式冷蔵室用蒸発器と強制対流式冷蔵室用蒸発器の両方に冷媒が流れることで自然対流式冷蔵室用蒸発器の庫内冷却と、強制対流式冷蔵室用蒸発器の庫内冷却がそれぞれ同時に行なえるようになる。この場合、自然対流式冷蔵室用蒸発器の庫内にあっては、庫内湿度を低下させることなく、即ち、乾燥を招くことなく庫内冷却が行なえる。
【００１５】
一方、自然対流式冷蔵室用蒸発器の運転中に、その庫内壁面に結露が発生した際には、自然対流式冷蔵室用蒸発器への冷媒の流れを停止し、強制対流式冷蔵室用蒸発器へのみ冷媒を流す運転を行なうことで、自然対流式冷蔵室用蒸発器の庫内壁面に発生した結露を効率よく蒸発させることが可能となる。
【００１６】
また、この発明の請求項３にあっては、各庫内空気温度が設定温度域を越えた時に、切換手段を切換えることを特徴とする。
【００１７】
これにより、庫内へ食料品等を多量に詰め込み庫内負荷が増えた時に、その庫内温度を正確に把握管理し、庫内負荷の大きい蒸発器側へ冷媒を流すことが可能となる。
【００１８】
また、この発明の請求項４にあっては、冷媒に、炭化水素系冷媒を用いることを特徴とする。
【００１９】
これにより、二酸化炭素の発生が抑えられ、地球温暖化防止に大きく貢献できるようになる。
【００２０】
【発明の実施の形態】
以下、図１乃至図４の図面を参照しながらこの発明の第１の実施形態について具体的に説明する。
【００２１】
図１はこの発明にかかる冷凍冷蔵庫の冷凍サイクルを構成する冷媒回路を示している。この冷媒回路には冷蔵室用冷凍サイクル及び冷凍室用冷凍サイクルをそれぞれ構成する２段圧縮機を有し、冷媒にはＲ６００ａのような炭化水素系の自然冷媒が用いられている。２段圧縮機１は、低圧側吸込口３と中間圧側吸込口５と吐出口７とを備え、低圧側吸込口３からの冷媒は中間圧まで加圧されるようになっている。中間圧側吸込口５からの冷媒は、前記中間圧まで加圧された冷媒と合流、混合して高圧まで加圧され、高圧まで加圧された冷媒は吐出口７から吐出されるようになっている。
【００２２】
２段圧縮機１の吐出口７から吐出された冷媒は、凝縮器９を通過した後、切換手段１１となる三方式切換弁１３の切換制御により第１ポートＢと第２ポートＡとに切換可能となっている。
【００２３】
第１ポートＢから吐出された冷媒は、絞り手段となる第１のキャピラリチューブ１５、冷蔵室用蒸発器１７、気液分離器１９に入ることでガス冷媒と液冷媒とに分離される。
【００２４】
分離された一方のガス冷媒は、サクションパイプ２１を介して再び２段圧縮機１の中間圧側吸込口５へ戻る冷蔵室用冷凍サイクル（実線矢印）が構成されるようになっている。気液分離器１９で分離された他方の液冷媒は、第２キャピラリチューブ３、冷凍室用蒸発器２５を通り、サクションパイプ２７を介して、再び、２段圧縮機１の低圧側吸込口３へ戻る冷凍室用冷凍サイクル（破線矢印）が構成されるようになっている。
【００２５】
一方、三方式切換弁１３の第２ポートＡから吐出された冷媒は、バイパスキャピラリチューブ２９、冷凍室用蒸発器２５を通り、前記したサクションパイプ２７を介して再び、２段圧縮機１の低圧側吸込口３へ戻る冷凍室用冷凍サイクルを構成するようになっている。
【００２６】
第１のキャピラリチューブ１５は、気液分離器１９のガス冷媒出口側のサクションパイプ２１と、バイパスキャピラリチューブ２９は冷凍室用蒸発器２５の出口側のサクションパイプ２７との間で対向流となるよう接近し合う並列配置となっていて、この並列配置領域はサクションパイプ２１，２７との間で熱交換が行なわれる熱交換領域３１となっている。
【００２７】
第２のキャピラリチューブ２３は、冷凍室用蒸発器２５の出口側のサクションパイプ２７との間で対向流となるよう接近し合う並列配置となっていて、この並列配置領域はサクションパイプ２７との間で熱交換が行なわれる熱交換領域３３となっている。
【００２８】
三方式切換弁１３は、冷蔵室用蒸発器１７の冷蔵室１７ａの庫内温度を検知する第１の温度センサ３５と冷凍室用蒸発器２５の冷凍室２５ａの庫内温度を検知する第２の温度センサ３７からの検知信号に基づいて第１ポートＢと第２ポートＡの切換制御が可能となっている。
【００２９】
第１，第２の温度センサ３５，３７からの検知信号は制御部３９に入力される。制御部３９は、第１、第２の温度センサ３５、３７からの検知信号に基づき、第１ポートＢ、第２ポートＡを同時に開としたり、あるいは、いずれか一方のポートＡを開、他方のポートＢを閉にそれぞれ切換制御可能となっている。
【００３０】
制御部３９は、前記した三方式切換弁１３の外に、２段圧縮機１の回転数と、図示していないが冷蔵室用蒸発器１７、冷凍室用蒸発器２５の各ファンを回転制御するようになっている。
【００３１】
図３は冷蔵室１７ａと冷凍室２５ａの庫内温度と設定温度との温度差に基づく三方式切換弁１３の制御側と２段圧縮機１の回転数の具体的な制御例を示している。図３において、Ｋは庫内温度と設定温度との温度差を示し、「２Ｋ〜」とあるのは温度差が２度以上あることを示している。「〜−２Ｋ」とあるのは温度差がマイナス２度まであることを示している。回転数とあるのは２段圧縮機１の回転数を、Ｂとあるのは第１ポート、Ａとあるのは第２ポートであることをそれぞれ示している。
【００３２】
見方としては、冷凍室２５ａの温度差を横移動し、冷蔵室１７ａの温度差を下方へ移動し、その交わった所が三方式切換弁１３と回転数の制御状態であることを示している。
【００３３】
一例として、例えば、冷凍室２５ａの温度差が「２Ｋ〜」、冷蔵室１７ａの温度差が「〜−２Ｋ」であると仮定した場合、その交わった所をみると、三方式切換弁１３はＢにある時、Ｂ→Ａに、Ａにある時、Ａ→Ａ（この場合変更なし）となり、すべてＡに切換わる。
【００３４】
一方、回転数はＵＰとなり、各温度差に基づく三方式切換弁１３の制御と回転数の制御は図３に基づき行なわれるようになっている。
【００３５】
このように構成された冷凍冷蔵庫において、三方式切換弁１３の第１ポートＢを開、第２ポートＡを閉とすることで、２段圧縮機１の吐出口７から吐出された冷媒は、凝縮器９、第１のキャピラリチューブ１５、冷蔵室用蒸発器１７を通り、気液分離器１９に入る。気液分離器１９においてガス冷媒と液冷媒とに分離され、一方のガス冷媒はサクションパイプ２１を介して再び、２段圧縮機１の中間圧側吸込口５に戻る連続した冷蔵室用冷凍サイクルを構成し、冷蔵室１７ａの所定の庫内温度が得られるようになる。
【００３６】
一方、気液分離器１９において他方の液冷媒は、冷凍室用蒸発器２５を通り、サクションパイプ２７を介して、再び、２段圧縮機１の低圧側吸込口３へ戻る連続した冷凍室用冷凍サイクルを構成し、冷凍室２５ａの所定の庫内温度が得られるようになる。
【００３７】
次に、三方式切換弁１３の第１ポートＢを閉、第２ポートＡを開とすることで、図２に示すように２段圧縮機１から吐出された冷媒は、凝縮器９、バイパスキャピラリチューブ２９、冷凍室用蒸発器２５を通り、再び、２段圧縮機１の低圧側吸込口３へ戻る連続した冷凍室用冷凍サイクルを構成し、冷凍室２５ａの所定の庫内温度が得られるようになる。この結果、例えば、冷蔵室１７ａに対し冷凍室２５ａの冷凍負荷が増えた場合でも、冷却不足を起こすことなく十分対応可能となる。この時の冷蔵室温度と冷凍室温度の制御パターンを図４に示す。この制御パターンにおいて、冷蔵室温度の右下がりの下降領域は、冷蔵室用蒸発器１７への冷媒の流れが停止していることを示している。
【００３８】
この右下がりの下降領域の時、冷蔵室用ファン（図示していない）を回転させることで、効率のよい除霜運転が行なえるようになる。
【００３９】
図５は、冷蔵室用蒸発器１７にかわって自然対流式冷蔵室用蒸発器４１と強制対流式冷蔵室用蒸発器４３とを備えた第２の実施形態を示したものである。
【００４０】
なお、第１の実施形態と同一のものは同一符号を符して説明する。
【００４１】
即ち、切換手段１１となる第１、第２、第３ポートＡ、Ｂ、Ｃを有する四方弁４５によって切換え制御される自然対流式冷蔵室用蒸発器４１と強制対流式冷蔵室用蒸発器４３とを並列配置とし、四方弁４５が第１ポートＡに切換わった時、２段圧縮機１の吐出口７から吐出された冷媒は、凝縮器９、絞り手段となる第１のキャピラリチューブ１５、自然対流式冷蔵室用蒸発器４１、強制対流式冷蔵室用蒸発器４３、気液分離器１９に入るようになっている。気液分離器１９でガス冷媒と液冷媒とに分離された一方のガス冷媒は、サクションパイプ２１を介して再び２段圧縮機１の中間圧側吸込口５へ戻る冷蔵室用冷凍サイクルが構成されるようになっている。気液分離器１９で分離された他方の液冷媒は、第２のキャピラリチューブ２３、冷凍室用蒸発器２５を通り、サクションパイプ２７を介して再び、２段圧縮機１の低圧側吸込口３へ戻る冷凍室用冷凍サイクルが構成され、自然対流式冷蔵室用蒸発器４１、強制対流式冷蔵室用蒸発器４３、冷凍室用蒸発器２５全てに冷媒が流れるようになっている。
【００４２】
また、四方弁４５が第２ポートＢに切換わった時、２段圧縮機１の吐出口７から吐出された冷媒は、凝縮器９、バイパスキャピラリチューブ２９、冷凍室用蒸発器２５、サクションパイプ２７を介して再び、２段圧縮機１の低圧側吸込口３へ戻る冷凍室用冷凍サイクルが構成され、冷凍室用蒸発器２５のみ冷媒が流れるようになっている。
【００４３】
また、四方弁４５が第３ポートＣに切換わった時、２段圧縮機１の吐出口７から吐出された冷媒は、凝縮器９、バイパスキャピラリチューブ４７、強制対流式冷蔵室用蒸発器４３、気液分離器１９に入るようになっている。気液分離器１９でガス冷媒と液冷媒とに分離された一方のガス冷媒は、サクションパイプ２１を介して再び２段圧縮機１の中間圧側吸込口５へ戻る冷蔵室用冷凍サイクルが構成されるようになっている。気液分離器１９で分離された他方の液冷媒は、第２のキャピラリチューブ２３、冷凍室用蒸発器２５を通り、サクションパイプ２７を介して再び、２段圧縮機１の低圧側吸込口３へ戻る冷凍室用冷凍サイクルが構成され、強制対流式冷蔵室用蒸発器４３と冷凍室用蒸発器２５に冷媒が流れるようになっている。
【００４４】
四方弁４５の各ポートＡ、Ｂ、Ｃの切換え制御は、自然対流式冷蔵室用蒸発器４１の庫内４１ａと強制対流式冷蔵室用蒸発器４３の庫内４３ａと冷凍室用蒸発器２５の庫内２５ａにそれぞれ設けられた各温度センサ５１からの情報が制御部３９に入力されることで、その温度情報に基づき切換え制御が行なわれるようになっている。庫内温度と設定温度との温度差に基づく四方弁４５と２段圧縮機１の回転数の具体的な制御例を図６に示す。なお、具体的な見方は図３と同様である。
【００４５】
したがって、この第２の実施形態によれば、例えば、自然対流式冷蔵室用蒸発器４１と強制対流式冷蔵室用蒸発器４３の両方に冷媒が流れることで、自然対流式冷蔵室用蒸発器４１の庫内冷却と、強制対流式冷蔵室用蒸発器４３の庫内冷却がそれぞれ同時に行なえるようになる。この運転時、自然対流式冷蔵室用蒸発器４１の庫内４１ａにあっては、庫内湿度を低下させることなく、即ち、乾燥を招くことなく庫内冷却が行なえる。
【００４６】
一方、自然対流式冷蔵室用蒸発器４１の運転中に、その庫内壁面に結露が発生した際には、自然対流式冷蔵室用蒸発器４１への冷媒の流れを停止し、強制対流式冷蔵室用蒸発器４３へ冷媒を流す運転を行なうことで、自然対流式冷蔵室用蒸発器４１の壁内壁面に発生した結露を効率よく迅速に蒸発させることが可能となる。
【００４７】
図７は、図１の冷媒回路から気液分離器を省略した第３の実施形態を示したものである。
【００４８】
即ち、切換手段１１となる三方式切換弁１３の第１ポートＡにキャピラリチューブ１５を介し冷蔵室用蒸発器１７を、第２ポートＢにキャピラリチューブ２９を介して冷凍室用蒸発器２５をそれぞれ接続し、冷蔵室用蒸発器１７の戻り用のサクションパイプ２１は２段圧縮機１の中間圧側吸込口５と、冷凍室用蒸発器２５の戻り用のサクションパイプ２７は２段圧縮機１の低圧側吸込口３とそれぞれ接続し合う構造となっている。
【００４９】
三方式切換弁１３と２段圧縮機１の回転数は、庫内温度と設定温度との温度差に基づき切換え制御されるもので、その具体的な制御例を図８に示す。見方は図３と同様である。
【００５０】
なお、他の構成要素は第１の実施形態と同一のため、同一符号を符して詳細な説明を省略する。
【００５１】
したがって、この第３の実施形態によれば、例えば、第１ポートＡ、第２ポートＢが開となることで、冷蔵室用蒸発器１７と冷凍室用蒸発器２５の両方に冷媒が流れる。この結果、冷蔵室用蒸発器１７の庫内冷却と、冷凍室用蒸発器２５の庫内冷却がそれぞれ同時に行なえるようになる。
【００５２】
一方、第１ポートＡ又は第２ポートＢのいずれか一方を選択して開とすることで、冷蔵室用蒸発器１７又は冷凍室用蒸発器２５のいずれか一方に冷媒が流れ、冷蔵室用蒸発器１７の庫内冷却、又は、冷凍室用蒸発器２５の庫内冷却が行なえるようになる。
【００５３】
したがって、庫内負荷に対応する蒸発器側へ冷媒を流すことが可能となり、一方の庫内が冷却不足を、あるいは、他方の庫内が過冷却を起こす等の不具合いがなくなり安定した庫内温度が得られるようになる。
【００５４】
なお、運転中に万一冷媒漏れが起きたとしても、自然冷媒を用いているため、地球環境に悪影響を与えることはない。
【００５５】
【発明の効果】
以上、説明したように、この発明の請求項１によれば、連続する冷蔵室の庫内冷却と冷凍室の庫内冷却を同時に行なうことができる。
【００５６】
また、例えば冷凍室の庫内負荷が大で、冷蔵室の庫内負荷が小の時には、冷凍室用蒸発器側に冷媒を流すことができるため、庫内負荷に対応した庫内冷却が効率よく行なえるようになる。
【００５７】
また、この発明の請求項２によれば、自然対流式冷蔵室用蒸発器の庫内冷却と強制対流式冷蔵室用蒸発器の庫内冷却が同時に行なうことができると共に、自然対流式冷蔵室用蒸発器にあっては庫内冷却を低下させることなく、即ち、乾燥を招くことなく庫内冷却が行なえる。
【００５８】
また、運転中に自然対流式冷蔵室用蒸発器の庫内壁面に結露が発生した際には、自然対流式冷蔵室用蒸発器への冷媒の流れを停止し、強制対流式冷蔵室用蒸発器へ冷媒を流す運転を行なうことができるため、自然対流式冷蔵室用蒸発器の庫内壁面に発生した結露を効率よく迅速に蒸発させることができる。
【００５９】
また、この発明の請求項３によれば、庫内へ食料品等を多量に詰め込み庫内負荷が増えた時に、その庫内負荷を正確に把握管理し、庫内負荷の大きい蒸発器側へ冷媒を流すことができる。
【００６０】
また、この発明の請求項４にあっては、二酸化炭素の発生を抑えることが可能となり地球温暖化防止に大きく貢献することができる。
【図面の簡単な説明】
【図１】この発明にかかる冷凍冷蔵庫の第１の実施形態を示した冷媒回路図。
【図２】三方式切換弁により、冷凍室用蒸発器側にのみ冷媒が流れた状態を示す図１と同様の冷媒回路図。
【図３】冷凍室と冷蔵室の庫内温度を設定温度の温度差に基づく三方式切換弁と２段圧縮機の回転数の具体的な制御例の説明図。
【図４】三方式切換弁の制御時の冷蔵室温度と冷凍室温度の動作説明図。
【図５】第２の実施形態を示した図１と同様の冷媒回路図。
【図６】第２の実施形態による庫内温度と設定温度の温度差に基づく四方弁と２段圧縮機の回転数の具体的な制御例の説明図。
【図７】第３の実施形態を示した図１と同様の冷媒回路図。
【図８】第３の実施形態による庫内温度と設定温度の温度差に基づく三方式切換弁と２段圧縮機の回転数の具体的な制御例を示した説明図。
【符号の説明】
１　２段圧縮機
３　低圧側吸込口
５　中間圧側吸込口
７　吐出口
９　凝縮器
１１　切換手段
１７　冷蔵室用蒸発器
１９　気液分離器
２５　冷凍室用蒸発器
４１　自然対流式冷蔵室用蒸発器
４３　強制対流式冷蔵室用蒸発器[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a refrigerating refrigerator having a refrigerating cycle for a refrigerator and a refrigerating cycle for a refrigerating compartment.
[0002]
[Prior art]
Recent freezer refrigerators have been equipped with a dedicated vegetable room, a freezer room, a freezer room, and the like. The freezer compartment requires a much lower internal temperature than the refrigerator compartment / vegetable compartment.Therefore, the refrigerator compartment / vegetable compartment is the temperature setting area by the refrigerator compartment refrigeration cycle, and the freezer compartment is the temperature setting by the freezer compartment refrigeration cycle. Independent temperature management is performed in each area.
[0003]
[Problems to be solved by the invention]
The refrigerating compartment refrigeration cycle and the compressor constituting the refrigerating compartment refrigeration cycle are two-stage compressors, a function of pressurizing the refrigerant from the low-pressure side suction port to an intermediate pressure, and a function of pressurizing the refrigerant to the intermediate pressure. And the refrigerant from the intermediate pressure side suction port are combined, mixed, pressurized to a high pressure, and discharged from the discharge port.
[0004]
Therefore, in the freezing room refrigeration cycle, the refrigerant discharged from the discharge port of the two-stage compressor passes through the condenser, the capillary tube, and the evaporator for the freezer room, and returns to the low-pressure side suction port of the two-stage compressor again. Thus, continuous cooling in the refrigerator compartment is obtained.
[0005]
In the refrigerating room refrigeration cycle, the refrigerant discharged from the discharge port of the two-stage compressor passes through the condenser, the capillary tube, and the evaporator for the refrigerator compartment, and returns to the intermediate pressure side suction port of the two-stage compressor again. Thus, continuous cooling in the refrigerator compartment can be obtained.
[0006]
In this case, the temperature range of the internal temperature of the freezer compartment can be controlled to some extent by the rotation speed of the freezer fan. Similarly, in the refrigerating compartment, it is possible to control the temperature range of the internal temperature to some extent by the number of revolutions of the refrigerating compartment fan. When the load in one of the compartments is greatly different, control by the rotation speed of the fan cannot be used, and a problem occurs in that one compartment has insufficient cooling and the other compartment has excessive cooling.
[0007]
Accordingly, an object of the present invention is to provide a refrigerator-freezer that does not cause insufficient cooling or excessive cooling even when the loads in the refrigerators are greatly different.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to claim 1 of the present invention, the refrigerant from the low pressure side suction port is combined with the refrigerant pressurized to the intermediate pressure and the refrigerant from the intermediate pressure side suction port, mixed and added to the high pressure. A refrigerator having a refrigerating cycle having a two-stage compressor for compressing and having a refrigerant discharged from the two-stage compressor at least a condenser, a refrigerator evaporator, and a freezer evaporator.
A circuit for flowing the refrigerant at the same time for both the refrigerating room evaporator and the freezing room evaporator, and a switching means for switching and controlling a circuit for selecting one of the refrigerating room evaporator and the freezing room evaporator and flowing the refrigerant. It is characterized by having.
[0009]
Thereby, by the switching control by the switching means, for example, a refrigeration cycle passing through both the refrigerator-room evaporator and the freezer-room evaporator can perform continuous cooling in the refrigerator and cooling in the refrigerator, respectively. Become like
[0010]
Next, for example, when the load in the freezer compartment becomes large by putting the frozen food, while the load in the refrigerator compartment is small, the switching control by the switching means causes only the refrigerant in the freezer evaporator to change. Is controlled to flow. As a result, the inside temperature corresponding to the inside load of the freezing room can be obtained, and there is no possibility of insufficient cooling.
[0011]
On the other hand, in the refrigerating room evaporator, since the load in the refrigerator is small, there is no problem in cooling the refrigerator even if the refrigerant does not flow. In this case, by using this time, for example, by rotating a fan, the defrosting operation of the evaporator for a refrigerator can be performed.
[0012]
In addition, by the switching control by the switching means, for example, by performing switching control so that the refrigerant flows only in the refrigerator compartment evaporator, the inside temperature corresponding to the inside load of the refrigerator compartment can be obtained.
[0013]
According to a second aspect of the present invention, there is provided a two-stage compressor that combines and mixes a refrigerant obtained by pressurizing a refrigerant from a low pressure side suction port to an intermediate pressure and a refrigerant from an intermediate pressure side suction port and pressurizes the refrigerant to a high pressure. Wherein the refrigerant discharged from the two-stage compressor has a refrigerating cycle including at least a condenser, a natural convection type refrigerator evaporator, a forced convection type refrigerator evaporator, and a freezing room evaporator. ,
The natural convection refrigeration compartment evaporator and the forced convection refrigeration compartment evaporator can be switched and controlled by switching means so that the refrigerant flows only at the same time or only one forced convection refrigeration compartment evaporator. It is characterized by the following.
[0014]
Thus, for example, the refrigerant flows through both the natural convection type refrigerator compartment evaporator and the forced convection type refrigerator compartment evaporator, thereby cooling the inside of the natural convection type refrigerator compartment evaporator and the forced convection type refrigerator compartment. Cooling of the inside of the evaporator can be performed at the same time. In this case, in the refrigerator of the natural convection type refrigerator evaporator, the refrigerator can be cooled without lowering the humidity in the refrigerator, that is, without causing drying.
[0015]
On the other hand, during the operation of the natural convection refrigeration compartment evaporator, if dew condensation occurs on the inner wall surface of the refrigerator, the flow of the refrigerant to the natural convection refrigeration compartment evaporator is stopped, and the forced convection refrigeration compartment is stopped. By performing the operation of flowing the refrigerant only to the evaporator for use, it is possible to efficiently evaporate the dew condensation generated on the inner wall surface of the evaporator for the natural convection type refrigerator.
[0016]
Further, according to a third aspect of the present invention, the switching means is switched when each in-compartment air temperature exceeds a set temperature range.
[0017]
Thus, when a large amount of foodstuffs or the like is packed in the refrigerator and the load in the refrigerator increases, it is possible to accurately grasp and manage the temperature in the refrigerator and to flow the refrigerant to the evaporator side having a large load in the refrigerator.
[0018]
According to a fourth aspect of the present invention, a hydrocarbon-based refrigerant is used as the refrigerant.
[0019]
As a result, the generation of carbon dioxide can be suppressed, and can greatly contribute to the prevention of global warming.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the first embodiment of the present invention will be described in detail with reference to FIGS.
[0021]
FIG. 1 shows a refrigerant circuit constituting a refrigeration cycle of a refrigerator according to the present invention. This refrigerant circuit has a refrigerating cycle for the refrigerator compartment and a two-stage compressor which respectively constitutes a refrigerating cycle for the freezer compartment, and a natural hydrocarbon-based refrigerant such as R600a is used as the refrigerant. The two-stage compressor 1 includes a low pressure side suction port 3, an intermediate pressure side suction port 5, and a discharge port 7, and the refrigerant from the low pressure side suction port 3 is pressurized to an intermediate pressure. The refrigerant from the intermediate pressure side suction port 5 joins and mixes with the refrigerant pressurized to the intermediate pressure and is pressurized to a high pressure. The refrigerant pressurized to the high pressure is discharged from the discharge port 7. I have.
[0022]
After passing through the condenser 9, the refrigerant discharged from the discharge port 7 of the two-stage compressor 1 is switched between the first port B and the second port A by the switching control of the three-system switching valve 13 serving as the switching means 11. It is possible.
[0023]
The refrigerant discharged from the first port B enters the first capillary tube 15 serving as a throttle means, the evaporator 17 for a refrigerator, and the gas-liquid separator 19 and is separated into a gas refrigerant and a liquid refrigerant.
[0024]
One of the separated gas refrigerants returns to the intermediate pressure side suction port 5 of the two-stage compressor 1 again through the suction pipe 21 to form a refrigerating room refrigeration cycle (solid line arrow). The other liquid refrigerant separated by the gas-liquid separator 19 passes through the second capillary tube 3 and the freezer evaporator 25, passes through the suction pipe 27, and returns to the low-pressure side suction port 3 of the two-stage compressor 1. A refrigeration cycle for the freezer compartment (broken arrow) is configured.
[0025]
On the other hand, the refrigerant discharged from the second port A of the three-way switching valve 13 passes through the bypass capillary tube 29 and the evaporator 25 for the freezing room, passes through the suction pipe 27 again, and returns to the low pressure of the two-stage compressor 1. The refrigeration cycle for the freezer compartment returning to the side suction port 3 is constituted.
[0026]
The first capillary tube 15 has a counterflow between the suction pipe 21 on the gas refrigerant outlet side of the gas-liquid separator 19, and the bypass capillary tube 29 has a counterflow between the suction pipe 27 on the outlet side of the freezer evaporator 25. The juxtaposed arrangement is such that the parallel arrangement region is a heat exchange region 31 in which heat exchange is performed between the suction pipes 21 and 27.
[0027]
The second capillary tube 23 is arranged in parallel to approach the suction pipe 27 on the outlet side of the freezer evaporator 25 so as to form a counterflow. A heat exchange area 33 where heat exchange is performed between the two.
[0028]
The three-system switching valve 13 includes a first temperature sensor 35 for detecting the temperature in the refrigerator 17a of the refrigerator evaporator 17 and a second temperature for detecting the temperature in the refrigerator 25a of the evaporator 25. The switching control between the first port B and the second port A can be performed based on the detection signal from the temperature sensor 37.
[0029]
The detection signals from the first and second temperature sensors 35 and 37 are input to the control unit 39. Based on the detection signals from the first and second temperature sensors 35 and 37, the control unit 39 opens the first port B and the second port A at the same time, or opens one of the ports A and the other. Can be controlled to close each of the ports B.
[0030]
The control unit 39 controls the rotation speed of the two-stage compressor 1 and the fans of the refrigerating room evaporator 17 and the freezing room evaporator 25 (not shown) in addition to the three-way switching valve 13. It is supposed to.
[0031]
FIG. 3 shows a specific control example of the control side of the three-system switching valve 13 and the rotation speed of the two-stage compressor 1 based on the temperature difference between the internal temperature of the refrigerator compartment 17a and the freezer compartment 25a and the set temperature. . In FIG. 3, K indicates a temperature difference between the inside temperature and the set temperature, and “2K or more” indicates that the temperature difference is 2 degrees or more. "~ -2K" indicates that the temperature difference is up to minus 2 degrees. The number of rotations indicates the number of rotations of the two-stage compressor 1, B indicates that it is the first port, and A indicates that it is the second port.
[0032]
From a viewpoint, the temperature difference in the freezer compartment 25a is laterally moved, the temperature difference in the refrigerator compartment 17a is moved downward, and the intersection is a control state of the three-way switching valve 13 and the rotation speed. .
[0033]
As an example, for example, assuming that the temperature difference of the freezer compartment 25a is “2K〜” and the temperature difference of the refrigerating compartment 17a is “〜-2K”, the three-way switching valve 13 is located at the intersection. When it is at B, it becomes B → A, and when it is at A, it becomes A → A (in this case, there is no change), and all are switched to A.
[0034]
On the other hand, the rotation speed is UP, and the control of the three-system switching valve 13 and the control of the rotation speed based on each temperature difference are performed based on FIG.
[0035]
In the refrigerator configured as described above, by opening the first port B and closing the second port A of the three-way switching valve 13, the refrigerant discharged from the discharge port 7 of the two-stage compressor 1 becomes: After passing through the condenser 9, the first capillary tube 15, and the evaporator 17 for the refrigerator, it enters the gas-liquid separator 19. The gas refrigerant and the liquid refrigerant are separated in the gas-liquid separator 19, and one of the gas refrigerants is returned to the intermediate-pressure side suction port 5 of the two-stage compressor 1 again through the suction pipe 21. With this configuration, a predetermined internal temperature of the refrigerator compartment 17a can be obtained.
[0036]
On the other hand, in the gas-liquid separator 19, the other liquid refrigerant passes through the freezer evaporator 25, passes through the suction pipe 27, and returns to the low-pressure side suction port 3 of the two-stage compressor 1 again. A refrigeration cycle is constituted, and a predetermined internal temperature of the freezing room 25a can be obtained.
[0037]
Next, by closing the first port B and opening the second port A of the three-way switching valve 13, the refrigerant discharged from the two-stage compressor 1 as shown in FIG. A continuous refrigeration cycle for the freezer compartment is configured to return to the low-pressure side suction port 3 of the two-stage compressor 1 through the capillary tube 29 and the evaporator 25 for the freezer compartment, and to obtain a predetermined temperature in the freezer compartment 25a. Will be able to As a result, for example, even when the refrigerating load of the freezing room 25a is increased with respect to the refrigerating room 17a, it is possible to sufficiently cope with the shortage of cooling. FIG. 4 shows a control pattern of the refrigerator compartment temperature and the freezer compartment temperature at this time. In this control pattern, the falling area of the refrigerator compartment temperature falling to the right indicates that the flow of the refrigerant to the refrigerator compartment evaporator 17 is stopped.
[0038]
By rotating the refrigerating compartment fan (not shown) in the downward-sloping region, an efficient defrosting operation can be performed.
[0039]
FIG. 5 shows a second embodiment provided with a natural convection type refrigerator evaporator 41 and a forced convection type refrigerator evaporator 43 in place of the refrigerator room evaporator 17.
[0040]
The same components as those of the first embodiment are denoted by the same reference numerals.
[0041]
That is, the natural convection type refrigerator evaporator 41 and the forced convection type refrigerator refrigerator evaporator 43, which are switched and controlled by the four-way valve 45 having the first, second, and third ports A, B, and C serving as the switching means 11. Are arranged in parallel, and when the four-way valve 45 is switched to the first port A, the refrigerant discharged from the discharge port 7 of the two-stage compressor 1 is supplied to the condenser 9 and the first capillary tube 15 serving as a throttle means. , A natural convection type refrigerator evaporator 41, a forced convection type refrigerator refrigerator evaporator 43, and a gas-liquid separator 19. One of the gas refrigerants separated into the gas refrigerant and the liquid refrigerant by the gas-liquid separator 19 returns to the intermediate pressure side suction port 5 of the two-stage compressor 1 again through the suction pipe 21 to form a refrigerating room refrigeration cycle. It has become so. The other liquid refrigerant separated by the gas-liquid separator 19 passes through the second capillary tube 23 and the freezer evaporator 25, passes through the suction pipe 27, and returns to the low-pressure side suction port 3 of the two-stage compressor 1. The refrigeration cycle for the freezer compartment is configured so that the refrigerant flows through all of the natural convection type refrigerator evaporator 41, the forced convection type refrigerator compartment evaporator 43, and the freezer compartment evaporator 25.
[0042]
When the four-way valve 45 is switched to the second port B, the refrigerant discharged from the discharge port 7 of the two-stage compressor 1 is supplied to the condenser 9, the bypass capillary tube 29, the freezer evaporator 25, and the suction pipe. A refrigerating room refrigerating cycle is configured to return to the low-pressure side suction port 3 of the two-stage compressor 1 again via 27, and the refrigerant flows only through the freezing room evaporator 25.
[0043]
When the four-way valve 45 is switched to the third port C, the refrigerant discharged from the discharge port 7 of the two-stage compressor 1 is supplied to the condenser 9, the bypass capillary tube 47, the forced convection type refrigerator evaporator 43. , Into the gas-liquid separator 19. One of the gas refrigerants separated into the gas refrigerant and the liquid refrigerant by the gas-liquid separator 19 returns to the intermediate pressure side suction port 5 of the two-stage compressor 1 again through the suction pipe 21 to form a refrigerating room refrigeration cycle. It has become so. The other liquid refrigerant separated by the gas-liquid separator 19 passes through the second capillary tube 23 and the freezer evaporator 25, passes through the suction pipe 27, and returns to the low-pressure side suction port 3 of the two-stage compressor 1. The refrigerating room refrigerating cycle is configured so that the refrigerant flows through the forced convection type refrigerator compartment evaporator 43 and the freezer compartment evaporator 25.
[0044]
The switching control of each of the ports A, B, and C of the four-way valve 45 is performed by controlling the inside 41a of the natural convection type refrigerator evaporator 41, the inside of the forced convection type refrigerator evaporator 43a, and the freezer evaporator 25. When information from each temperature sensor 51 provided in each of the insides 25a is input to the control unit 39, switching control is performed based on the temperature information. FIG. 6 shows a specific control example of the rotational speeds of the four-way valve 45 and the two-stage compressor 1 based on the temperature difference between the inside temperature and the set temperature. The specific viewpoint is the same as in FIG.
[0045]
Therefore, according to the second embodiment, for example, the refrigerant flows through both the natural convection type refrigerator compartment evaporator 41 and the forced convection type refrigerator compartment evaporator 43, so that the natural convection type refrigerator evaporator is provided. The internal cooling of the refrigerator 41 and the internal cooling of the forced convection type refrigerator evaporator 43 can be simultaneously performed. During this operation, in the inside 41a of the natural convection type refrigerator evaporator 41, the inside can be cooled without lowering the inside humidity, that is, without causing drying.
[0046]
On the other hand, during the operation of the natural convection type refrigerator compartment evaporator 41, when dew condensation occurs on the inner wall surface of the refrigerator, the flow of the refrigerant to the natural convection type refrigerator compartment evaporator 41 is stopped, and the forced convection type evaporator 41 is stopped. By performing the operation of flowing the refrigerant to the refrigerator compartment evaporator 43, it is possible to efficiently and quickly evaporate the dew condensation generated on the inner wall surface of the natural convection refrigerator compartment evaporator 41.
[0047]
FIG. 7 shows a third embodiment in which the gas-liquid separator is omitted from the refrigerant circuit of FIG.
[0048]
That is, the evaporator 17 for the refrigerator compartment is connected to the first port A of the three-way switching valve 13 serving as the switching means 11 via the capillary tube 15, and the evaporator 25 for the freezer compartment is connected to the second port B via the capillary tube 29. The return suction pipe 21 of the refrigerator compartment evaporator 17 is connected to the intermediate pressure side suction port 5 of the two-stage compressor 1, and the return suction pipe 27 of the freezer compartment evaporator 25 is connected to the two-stage compressor 1. The low pressure side suction port 3 is connected to each other.
[0049]
The number of rotations of the three-system switching valve 13 and the two-stage compressor 1 is switched and controlled based on the temperature difference between the internal temperature and the set temperature, and a specific control example is shown in FIG. The viewpoint is the same as in FIG.
[0050]
The other components are the same as those in the first embodiment, and thus the same reference numerals are used and detailed description is omitted.
[0051]
Therefore, according to the third embodiment, for example, when the first port A and the second port B are opened, the refrigerant flows through both the refrigerator compartment evaporator 17 and the freezer compartment evaporator 25. As a result, cooling in the refrigerator evaporator 17 and cooling in the freezer evaporator 25 can be simultaneously performed.
[0052]
On the other hand, by selecting and opening one of the first port A and the second port B, the refrigerant flows into one of the refrigerator compartment evaporator 17 and the freezer compartment evaporator 25, and Cooling of the inside of the evaporator 17 or cooling of the inside of the freezer evaporator 25 can be performed.
[0053]
Therefore, it is possible to flow the refrigerant to the evaporator side corresponding to the load in the refrigerator, and there is no trouble such as insufficient cooling in one refrigerator or excessive cooling in the other refrigerator, and a stable refrigerator Temperature can be obtained.
[0054]
Note that even if a refrigerant leak occurs during operation, the natural environment is used, so that there is no adverse effect on the global environment.
[0055]
【The invention's effect】
As described above, according to the first aspect of the present invention, it is possible to simultaneously perform continuous cooling in the refrigerator compartment and cooling in the freezer compartment.
[0056]
In addition, for example, when the load in the freezer compartment is large and the load in the refrigerator compartment is small, the refrigerant can flow to the freezer evaporator side, so that the cooling in the compartment corresponding to the load in the refrigerator is efficient. You can do well.
[0057]
In addition, according to the second aspect of the present invention, the internal cooling of the evaporator for the natural convection type refrigerator compartment and the internal cooling of the evaporator for the forced convection type refrigerator compartment can be performed simultaneously, and the natural convection type refrigerator compartment is provided. In the evaporator for use, cooling in the refrigerator can be performed without lowering the cooling in the refrigerator, that is, without causing drying.
[0058]
If condensation forms on the inner wall of the natural convection refrigerator compartment evaporator during operation, the flow of the refrigerant to the natural convection refrigerator refrigerator evaporator is stopped, and the forced convection refrigerator refrigerator evaporator is stopped. Since the operation of flowing the refrigerant into the refrigerator can be performed, the dew condensation generated on the inner wall surface of the natural convection type refrigerator evaporator can be quickly and efficiently evaporated.
[0059]
According to the third aspect of the present invention, when a large amount of foodstuffs is packed in the refrigerator and the load in the refrigerator increases, the load in the refrigerator is accurately grasped and managed, and the evaporator having a large load in the refrigerator is controlled. Refrigerant can flow.
[0060]
Further, according to claim 4 of the present invention, it is possible to suppress the generation of carbon dioxide, which can greatly contribute to prevention of global warming.
[Brief description of the drawings]
FIG. 1 is a refrigerant circuit diagram showing a first embodiment of a refrigerator-freezer according to the present invention.
FIG. 2 is a refrigerant circuit diagram similar to FIG. 1 showing a state in which refrigerant flows only to the freezer evaporator side by a three-way switching valve.
FIG. 3 is an explanatory diagram of a specific control example of the rotation speed of a three-way switching valve and a two-stage compressor based on a temperature difference between a set temperature and a temperature inside a refrigerator room and a refrigerator room.
FIG. 4 is an explanatory diagram of the operation of the refrigerator compartment temperature and the freezer compartment temperature when controlling the three-way switching valve.
FIG. 5 is a refrigerant circuit diagram similar to FIG. 1 showing a second embodiment.
FIG. 6 is an explanatory diagram of a specific control example of the rotation speed of the four-way valve and the two-stage compressor based on the temperature difference between the inside temperature and the set temperature according to the second embodiment.
FIG. 7 is a refrigerant circuit diagram similar to FIG. 1 showing a third embodiment.
FIG. 8 is an explanatory diagram showing a specific control example of the rotation speed of the three-system switching valve and the two-stage compressor based on the temperature difference between the internal temperature and the set temperature according to the third embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 2 stage compressor 3 Low pressure side suction port 5 Intermediate pressure side suction port 7 Discharge port 9 Condenser 11 Switching means 17 Cold room evaporator 19 Gas-liquid separator 25 Freezing room evaporator 41 Natural convection type cold room evaporator 43 Evaporator for forced convection refrigerator

Claims

It has a two-stage compressor that joins, mixes, and pressurizes the refrigerant from the low-pressure side suction port to the intermediate pressure and the refrigerant from the intermediate-pressure side suction port, and pressurizes the refrigerant from the two-stage compressor to the high pressure. At least a condenser, a refrigerator refrigerator evaporator, a refrigerator having a refrigerating cycle passing through the freezer evaporator,
A circuit for flowing the refrigerant at the same time for both the refrigerating room evaporator and the freezing room evaporator, and a switching means for switching and controlling a circuit for selecting one of the refrigerating room evaporator and the freezing room evaporator and flowing the refrigerant. A refrigerator comprising: a refrigerator;

It has a two-stage compressor that joins, mixes, and pressurizes the refrigerant from the low-pressure side suction port to the intermediate pressure and the refrigerant from the intermediate-pressure side suction port, and pressurizes the refrigerant from the two-stage compressor to the high pressure. At least a condenser, a natural convection type cold room evaporator, a forced convection type cold room evaporator, a refrigerator having a refrigeration cycle through a freezing room evaporator,
The natural convection refrigeration compartment evaporator and the forced convection refrigeration compartment evaporator can be switched and controlled by switching means so that the refrigerant flows only at the same time or only one forced convection refrigeration compartment evaporator. A refrigerator-freezer comprising:

3. The refrigerator according to claim 1, wherein the switching means switches when the air temperature in each refrigerator exceeds a set temperature range.

The refrigerator according to claim 1 or 2, wherein the refrigerant is a hydrocarbon-based refrigerant.