JP3576040B2

JP3576040B2 - Cooling systems and refrigerators

Info

Publication number: JP3576040B2
Application number: JP16329699A
Authority: JP
Inventors: 哲哉斎藤; 義人木村; 泰樹浜野; 信雄下村
Original assignee: 松下冷機株式会社
Priority date: 1999-06-10
Filing date: 1999-06-10
Publication date: 2004-10-13
Anticipated expiration: 2019-06-10
Also published as: JP2000346526A

Description

【０００１】
【発明の属する技術分野】
本発明は、冷蔵庫などにもちいる冷却システムに関するものである。
【０００２】
【従来の技術】
図１２に従来の冷却サイクル並びに冷蔵庫の一例として、特公昭６２−２２３９６号公報に開示されている冷蔵庫の概略図を示す。
【０００３】
１は一定速圧縮機、２は凝縮器、３は冷蔵室４内に配設された第一の蒸発器であり、５は冷凍室６内に配設された第二の蒸発器である。
【０００４】
７は冷蔵室冷却用である第一の蒸発器３の冷媒回路上流側に配設された第一の減圧手段（キャピラリ）であり、８は冷凍室冷却用である第二の蒸発器５の冷媒回路上流側に配設された第二の減圧手段（キャピラリ）であり、９は冷凍室冷却用の第二の蒸発器５の下流側に設けた逆止弁である。
【０００５】
１０は第一の蒸発器３の冷媒回路下流側に配設された第一の開閉弁であり、１１は第二のキャピラリ８の冷媒回路上流側に設けられた第二の開閉弁である。
【０００６】
以上のように構成された従来例の冷蔵庫について、以下その動作を説明する。
【０００７】
冷凍サイクルの運転は以下のように行われる。まず圧縮機１により圧縮された冷媒が凝縮器２で凝縮液化される。凝縮された冷媒は第一のキャピラリ７もしくは第二のキャピラリ８で減圧されて、それぞれ第一の蒸発器３、第二の蒸発器５へ流入、蒸発気化された後、再び圧縮機１へと吸入される。
【０００８】
冷媒が蒸発気化することにより比較的低温となった第一の蒸発器３、第二の蒸発器５と冷蔵室４、冷凍室６の空気が熱交換することにより各室が冷却される。
【０００９】
冷蔵庫の冷却運転は図示しない各室の温度検知手段と制御手段により以下のように行われる。
【００１０】
冷蔵室４、冷凍室６の各温度検知手段が所定値以上の温度上昇を検知すると圧縮機１が起動し、冷凍サイクルの運転が行われる。冷蔵室４の温度検知手段が所定値以下となるまで第一の開閉弁１０が開放となり、第二の開閉弁１１は閉止となる。
【００１１】
これにより冷媒は第二の蒸発器５には流入することなく、第一の蒸発器３へのみ流れる。このときの冷凍サイクルの蒸発温度の設定は、冷蔵室４の温度設定が５℃程度に対して−５〜０℃であり、通常の−３０〜−２５℃の蒸発温度に対して２〜２．５倍の成績係数で圧縮機の運転が可能である。
【００１２】
冷蔵室４が冷却されて温度が低下し、温度検知手段が所定値以下を検知すると、第一の開閉弁１０が閉止し、第二の開閉弁１１が開放となる。
【００１３】
これにより冷媒は第二の蒸発器５へと流入し、冷凍室６の冷却が行われる。このときの冷凍サイクルの蒸発温度は冷凍室の温度設定が−１８℃程度に対し通常の蒸発温度で冷却される。
【００１４】
以上のように冷蔵室４と冷凍室６とを蒸発器への冷媒供給時間を分配して、交互に繰り返し冷却するので、冷蔵室４冷却時は独立的に冷媒を第一の蒸発器へと循環させることで低圧圧力調整弁が不要で高蒸発温度（−５〜０℃）が可能であり、圧縮機１の圧縮比を小さくでき、高い成績係数で運転を行い効率化を図るものである。
【００１５】
さらに、逆止弁９は冷蔵室４冷却中の蒸発温度が高いので、第二の蒸発器５に冷媒が流れ込むを防止するものである。
【００１６】
また、冷凍室６の冷却を行う場合、冷蔵室４の冷却中に比較して冷媒量が少なくてすむので、通常は冷媒量過多となる。しかしながら第一の開閉弁１０が第一の蒸発器３の下流側に設けてあり、これを閉止するので第一の蒸発器３に冷媒を溜め込むことが可能であり、冷媒量調節ができる。
【００１７】
【発明が解決しようとする課題】
上記従来の冷蔵庫にあっては、冷蔵室４と冷凍室６とを蒸発器への冷媒供給時間を分配して、交互に繰り返し冷却することで冷蔵室４冷却時の冷凍サイクルを圧縮機１の成績係数がよい比較的高蒸発温度（−５〜０℃）で運転することを可能としている。
【００１８】
しかし、冷蔵室４冷却時において冷凍室６の温度が例えば約−１８℃と低いために冷凍室６内に配設された第二の蒸発器５の圧力は低圧となるので、第二の蒸発器５に滞留した冷媒は第二の蒸発器５から流出しにくい。その結果、第一の蒸発器３に十分な冷媒が供給されず、冷媒循環量不足となり効率が低下することとなる。
【００１９】
上記の要因により、必要な冷媒量が増大し、可燃性冷媒を用いる場合には冷媒漏洩時の危険性が大きく問題がある。
【００２０】
また、圧縮機１停止中に冷凍室６の温度が例えば約−１８℃と最も低いために冷凍室６内に配設された第二の蒸発器５の圧力が冷凍サイクル内で最も低圧となり、凝縮器内の高圧冷媒が第二の蒸発器５に移動し滞留するので、圧縮機１起動時に圧縮機１に液冷媒が流入し、圧縮機１が故障する原因となるばかりでなく、圧縮機起動時に速やかに蒸発器に安定して冷媒が供給されるまでに時間的遅れが生じ、効率低下の原因となる。
【００２１】
本発明は、以上のような従来の課題を解決するもので、冷蔵室と冷凍室の冷却を切り替えて行う冷却システムの冷媒量削減と効率向上を行うことで、省エネルギーが可能な冷蔵庫を提供することを目的とする。
【００２２】
【課題を解決するための手段】
本発明の請求項１に記載の冷却システムは、圧縮機と、凝縮器と、この凝縮器からの冷媒を分流する第一の流路制御手段と第二の流路制御手段と、前記第一の流路制御手段に連結された第一の減圧手段と、この第一の減圧手段と連結された第一の蒸発器と、前記第二の流路制御手段に連結された第二の減圧手段と、この第二の減圧手段と連結された第二の蒸発器と、前記第二の蒸発器の配管温度を検出する温度検出手段とを備え、前記冷媒を可燃性冷媒とし、前記第一の流路制御手段の流路が閉でかつ第二の流路制御手段の流路が開であり前記第二の蒸発器に冷媒が流入している状態から、前記第一の流路制御手段の流路が開でかつ前記第二の流路制御手段の流路が閉となり前記第一の蒸発器に冷媒が流入する状態に冷媒の流れを切り替えるとき、前記第一、第二の流路制御弁を閉とした後に、前記第二の蒸発器の配管温度を検出する温度検出手段が所定温度まで上昇した時、前記第一の流路制御手段の流路を開とする制御手段を備えたものである。
【００２３】
このことにより、第二の蒸発器に冷媒が流入した冷凍室の冷却状態から、第一の蒸発器に冷媒が流入する冷蔵室の冷却状態へ切り替わるとき、両流量制御手段を所定時間閉とするので、冷媒の流れが完全に遮断された状態で圧縮機が運転されるため、圧縮機内の圧力が通常運転と比較して低圧となるので、第二の蒸発器内に滞留していた冷媒を第二の蒸発器から追い出すことが可能となる。
【００２４】
その結果、冷媒の循環量が不足することが無く効率よく運転できるものである。
【００２５】
また、冷媒が効率よく利用されることは従来に比べて冷媒量を削減できるので、可燃性冷媒の冷媒漏れによる危険性を小さくすることができる。
【００２７】
また、冷媒の流れが完全に遮断された状態で圧縮機を運転すると第二の蒸発器内に滞留していた気液二層状態の冷媒は、圧力が下がるために蒸発しながら第二の蒸発器から圧縮機へ移動するので第二の蒸発器に冷媒が残留している間は、第二の蒸発器の配管温度は低温となる。
【００２８】
すなわち、速やかに第一の蒸発器の冷却に冷媒を供給できるので冷媒循環量不足になることがない。
【００２９】
本発明の請求項２記載の冷却システムは、圧縮機と、凝縮器と、この凝縮器からの冷媒を分流する第一の流路制御手段と第二の流路制御手段と、前記第一の流路制御手段に連結された第一の減圧手段と、この第一の減圧手段と連結された第一の蒸発器と、前記第二の流路制御手段に連結された第二の減圧手段と、この第二の減圧手段と連結された第二の蒸発器とを備え、前記冷媒を可燃性冷媒とし、前記第一の流路制御手段の流路が閉でかつ第二の流路制御手段の流路が開であり前記第二の蒸発器に冷媒が流入している状態から、前記第一の流路制御手段の流路が開でかつ前記第二の流路制御手段の流路が閉となり前記第一の蒸発器に冷媒が流入する状態に冷媒の流れを切り替えるとき、前記第一の流路制御弁を断続的に所定時間閉とした後に、前記第一の流路制御手段の流路を開とする制御手段を備えたものである。
【００３０】
このように圧縮機を断続運転することにより、圧縮機に流れる冷媒の圧力を段階的に低下させることができるので、圧力の急低下による圧縮機の損傷を防ぐことができる。
【００３１】
また、冷媒が効率よく利用されることは従来に比べて冷媒量を削減できるので、可燃性冷媒の冷媒漏れによる危険性を小さくすることができる。
【００３２】
本発明の請求項３記載の冷蔵庫は、冷蔵室と冷凍室を備えた箱体と、圧縮機、凝縮器、この凝縮器からの冷媒を分流する第一の流路制御手段と第二の流路制御手段、前記第一の流路制御手段の下流側に連結された第一の減圧手段、この第一の減圧手段と連結された第一の蒸発器、前記第二の流路制御手段の下流側に連結された第二の減圧手段、及び、この第二の減圧手段と連結された第二の蒸発器を備えた冷凍サイクルとを有し、前記第一の冷却器により前記冷蔵室を冷却し、前記第二の冷却器により前記冷凍室を冷却するものであって、前記冷媒を可燃性冷媒とし、前記圧縮機は、吸入冷媒が圧縮機内空間に放出される低圧容器型でかつインバーターによる回転数制御で冷媒循環量を変化できる能力可変型であり、前記第一の流路制御手段と第二の流路制御手段とを機械室内に配設する三方弁で構成したものであって、前記冷蔵室及び前記冷凍室の温度検知手段がともに設定温度以下になったとき、前記三方弁を閉として前記圧縮機を停止し、前記圧縮機の停止中は前記三方弁を閉としたまま前記冷媒の前記第一、第二の蒸発器への移動を防止するものである。
【００３３】
このことにより、圧縮機停止中は冷凍室の温度が最も低いために第二の蒸発器の圧力が冷凍サイクル内で最も低圧となり、凝縮器内の高圧冷媒が第二の蒸発器内へ移動し滞留するので冷却開始時に第二の蒸発器に速やかに冷媒を供給できず効率低下の原因となっていたが、圧縮機停止中は第一の電動弁と第二の電動弁を閉止するために第一の蒸発器と第二の蒸発器への冷媒の移動は妨げられ、圧縮機起動時に速やかに第二の蒸発器に冷媒を供給することができるので冷媒循環量不足にならず、効率よく冷凍室を冷却することが可能となる。
【００３４】
本発明の請求項４に記載の冷蔵庫は、圧縮機を停止する前に、第一の流路制御手段と第二の流路制御手段を閉止し、冷媒の流れが完全に遮断された状態で圧縮機を所定時間運転するので、圧縮機に流入する冷媒の圧力は低下し第一の蒸発器と第二の蒸発器に滞留している冷媒を圧縮機側へ追い出すことが可能となる。
【００３６】
【発明の実施の形態】
本発明の請求項１に記載の発明は、圧縮機と、凝縮器と、この凝縮器からの冷媒を分流する第一の流路制御手段と第二の流路制御手段と、前記第一の流路制御手段に連結された第一の減圧手段と、この第一の減圧手段と連結された第一の蒸発器と、前記第二の流路制御手段に連結された第二の減圧手段と、この第二の減圧手段と連結された第二の蒸発器と、前記第二の蒸発器の配管温度を検出する温度検出手段とを備え、前記冷媒を可燃性冷媒とし、前記第一の流路制御手段の流路が閉でかつ第二の流路制御手段の流路が開であり前記第二の蒸発器に冷媒が流入している状態から、前記第一の流路制御手段の流路が開でかつ前記第二の流路制御手段の流路が閉となり前記第一の蒸発器に冷媒が流入する状態に冷媒の流れを切り替えるとき、前記第一、第二の流路制御弁を閉とした後に、前記第二の蒸発器の配管温度を検出する温度検出手段が所定温度まで上昇した時、前記第一の流路制御手段の流路を開とする制御手段を備えたことを特徴とする。
【００４１】
このことにより、第一の流路制御手段および第二の流路制御手段の流路を閉とし、冷媒の流れが完全に遮断された状態で圧縮機を運転すると第二の蒸発器内に滞留していた気液二相状態の冷媒は、圧力が下がるために蒸発しながら第二の蒸発器から圧縮機へ移動するので第二の蒸発器に冷媒が残留している間は、第二の蒸発器の配管温度は冷凍室温度より低温となる。そして、冷媒の残留量が少なくなるにつれて上昇し冷凍室温度に近づく。
【００４２】
第二の蒸発器の配管温度が、例えば冷凍室温度と等しくなった時、第二の蒸発器内に滞留していた冷媒がほとんどなくなったと判断し、第一の流路制御手段を開放し冷蔵室の冷却を開始する。
【００４３】
これにより、蒸発器の運転が切り替わる時、最も効率よく第二の蒸発器内に滞留していた冷媒を追い出すことができ、速やかに第一の蒸発器に冷媒を供給できるので冷媒循環量不足にならず、さらに効率よく運転することが可能となる。
【００４４】
本発明の請求項２に記載の発明は、圧縮機と、凝縮器と、この凝縮器からの冷媒を分流する第一の流路制御手段と第二の流路制御手段と、前記第一の流路制御手段に連結された第一の減圧手段と、この第一の減圧手段と連結された第一の蒸発器と、前記第二の流路制御手段に連結された第二の減圧手段と、この第二の減圧手段と連結された第二の蒸発器とを備え、前記冷媒を可燃性冷媒とし、前記第一の流路制御手段の流路が閉でかつ第二の流路制御手段の流路が開であり前記第二の蒸発器に冷媒が流入している状態から、前記第一の流路制御手段の流路が開でかつ前記第二の流路制御手段の流路が閉となり前記第一の蒸発器に冷媒が流入する状態に冷媒の流れを切り替えるとき、前記第一の流路制御弁を断続的に所定時間閉とした後に、前記第一の流路制御手段の流路を開とする制御手段を備えたものである。
【００４５】
これにより、冷凍室冷却から冷蔵室冷却に切り替わる時に圧縮機に流入する冷媒の圧力を段階的に低下させることができるので、圧力の急低下による圧縮機への負担を低減し、損傷を防ぐことが可能となる。
【００４６】
また、その結果、第一の流路制御手段と第二の流路制御手段を共に閉止して第二の蒸発器内に滞留した冷媒を追い出す場合と比較して、より長い間第二の蒸発器内に滞留した冷媒を追い出すことができるので、さらに効率よく冷蔵室の冷却を行うことが可能となる。
【００４７】
また、上記の結果より冷媒を効率よく利用することができるので可燃性冷媒の冷媒量を削減でき、冷媒漏洩時の危険性を小さくすることが可能となる。
【００４８】
本発明の請求項３に記載の発明は、冷蔵室と冷凍室を備えた箱体と、圧縮機、凝縮器、この凝縮器からの冷媒を分流する第一の流路制御手段と第二の流路制御手段、前記第一の流路制御手段の下流側に連結された第一の減圧手段、この第一の減圧手段と連結された第一の蒸発器、前記第二の流路制御手段の下流側に連結された第二の減圧手段、及び、この第二の減圧手段と連結された第二の蒸発器を備えた冷凍サイクルとを有し、前記第一の冷却器により前記冷蔵室を冷却し、前記第二の冷却器により前記冷凍室を冷却するものであって、前記冷媒を可燃性冷媒とし、前記圧縮機は、吸入冷媒が圧縮機内空間に放出される低圧容器型でかつインバーターによる回転数制御で冷媒循環量を変化できる能力可変型であり、前記第一の流路制御手段と第二の流路制御手段とを機械室内に配設する三方弁で構成したものであって、前記冷蔵室及び前記冷凍室の温度検知手段がともに設定温度以下になったとき、前記三方弁を閉として前記圧縮機を停止し、前記圧縮機の停止中は前記三方弁を閉としたまま前記冷媒の前記第一、第二の蒸発器への移動を防止する冷蔵庫である。
【００４９】
圧縮機停止中は冷凍室の温度が最も低いために第二の蒸発器の圧力が冷凍サイクル内で最も低圧となり、凝縮器内の高圧冷媒が第二の蒸発器内へ移動し滞留するので冷却開始時に第二の蒸発器に速やかに冷媒を供給できず効率低下の原因となっていたが、圧縮機停止中は第一の電動弁と第二の電動弁を閉止するために第一の蒸発器と第二の蒸発器への冷媒の移動は妨げられ、圧縮機起動時に速やかに第二の蒸発器に冷媒を供給することができるので冷媒循環量不足にならず、効率よく冷凍室を冷却することが可能となる。
また、冷媒を効率よく利用することができるので可燃性冷媒の冷媒量を削減でき、冷媒漏洩時の危険性を小さくすることが可能となる。
【００５０】
本発明の請求項４に記載の発明は、圧縮機を停止する前に、第一の流路制御手段と第二の流路制御手段を閉止し、冷媒の流れが完全に遮断された状態で圧縮機を所定時間運転するので、圧縮機に流入する冷媒の圧力は低下し第一の蒸発器と第二の蒸発器に滞留している冷媒を圧縮機側へ追い出すことが可能となる。
【００５２】
以下、本発明の実施の形態について図１〜図６を用いて説明する。従来例と同一構成についてはその詳細な説明を省略し、同一符号を付す。
【００５３】
（実施の形態１）
図１は、本発明の実施例１における冷蔵庫の概略図、図２は同実施例のタイムチャートである。
【００５４】
２０は冷蔵庫箱体であり、上方部に比較的高温の区画である冷蔵室４を、下方部に比較的低温の冷凍室６を配置してあり、例えばウレタンのような断熱材で周囲を断熱して構成している。食品等の収納物の出し入れは図示しない断熱ドアを介して行われる。
【００５５】
冷蔵室４は冷蔵保存のために通常３〜５℃で設定されているが、保鮮性向上のため若干低めの温度、例えば−３〜０℃で設定されることもあり、収納物によって、使用者が自由に上記のような温度設定を切り替えることを可能としている場合もある。また、ワインや根野菜等の保鮮のために、例えば１０℃前後の若干高めの温度設定とする場合もある。
【００５６】
冷凍室６は冷凍保存のために通常−２２〜−１８℃で設定されているが、保鮮性向上のためより低温の温度、例えば−３０〜−２５℃で設定されることもある。
【００５７】
冷凍サイクル１２は圧縮機１と凝縮器２と第一の流路制御手段である第一の電動弁１０と第一の減圧手段である第一のキャピラリ７と第一の蒸発器３を順次接続し、第一の電動弁１０と第一のキャピラリ７と第一の蒸発器３と並列になるように第二の流路制御手段である第二の電動弁１１と第二の減圧手段である第二のキャピラリ８と第二の蒸発器５を接続してある。
【００５８】
第一の蒸発器３は冷蔵室４内の、例えば冷蔵室奥面に配設されており、近傍には冷蔵室４の区画内空気を第一の蒸発器３に通過させて循環させる第一の電動ファン１３が設けてある。
【００５９】
また、第二の蒸発器５は冷凍室６内の、例えば冷凍室奥面に配設されており、近傍には冷凍室６の区画内空気を第二の蒸発器５を通過させて循環させる第二の電動ファン１４が設けてある。
【００６０】
圧縮機１と凝縮器２と第一の電動弁１０と第二の電動弁１１は可燃性冷媒を使用した場合に安全性向上の面から冷蔵庫箱体２０内での配管接続箇所削減のために機械室１５に配設されている。
【００６１】
各蒸発器から戻ってくる冷媒は圧縮機吸入管１６を通って、圧縮機１内空間へ放出された後、圧縮機吐出管１７を通じて吐出される構成である。
【００６２】
さらに圧縮機１は例えばインバーターによる回転数制御で冷媒循環量を制御し冷凍能力を変化させることができる能力可変型としてある。
【００６３】
また、冷蔵室４と冷凍室６には区画内温度を検知する、例えばサーミスタである温度検知手段Ｔｈ１，Ｔｈ２を設けてあり、能力可変型圧縮機１と第一の電動弁１０と第二の電動弁１１と第一の電動ファン１３と第二の電動ファン１４とを制御する制御手段Ｃ１とを備えている。２１は逆止弁で、第二の蒸発器５と圧縮機１の間に介在され、冷媒の逆流を防止している。
【００６４】
ここで、第一の電動弁と第二の電動弁と第一のファンと第二のファンの基本動作について説明する。
【００６５】
圧縮機運転中、第一の電動弁１０は冷蔵室４の温度検知手段が予め設定された所定の温度を超えている場合は開放動作を行い、また予め設定された所定の温度より低い場合は閉止動作を行う。また、第一の電動ファン１３も同様に冷蔵室４の温度検知手段が予め設定された所定の温度を超えている場合は運転を行い、また予め設定された所定の温度より低い場合は停止する。
【００６６】
また、圧縮機運転中、第二の電動弁１１は冷蔵室４の温度検知手段が予め設定された所定の温度より低い場合は開放動作を行い、また予め設定された所定の温度より高い場合は閉止動作を行う。また、第二の電動ファン１４も同様に冷蔵室４の温度検知手段が予め設定された所定の温度より低い場合は運転を行い、また予め設定された所定の温度より高い場合は停止する。
【００６７】
以上のように構成された冷蔵庫について、冷蔵室４と冷凍室６の冷却タイミングについて図２のタイムチャートをもとに説明する。
【００６８】
圧縮機停止中に、冷凍室６内の温度が上昇すると、冷凍室６の温度検知手段が、予め設定された所定の温度を超えることを検知する。制御手段はこの信号を受けて、圧縮機１と第二の電動ファン１４を作動し、第二の電動弁１１を開放し、第一の電動弁を閉止する（Ｔ１）。
【００６９】
圧縮機１の動作により吐出された高温高圧の冷媒は、凝縮器２にて放熱して凝縮液化し、第二の電動弁１１を経て第二のキャピラリ８に至る。その後、第二のキャピラリ８で第二のサクションライン１９と熱交換しながら減圧されて第二の蒸発器５に至る。第二の電動ファン１４の作動により冷凍室６内の空気と積極的に熱交換されて冷媒は第二の蒸発器５内で蒸発気化し熱交換された空気はより低温の空気となって吐出され冷凍室６を冷却する。気化した冷媒は、第二のサクションライン１９を経て圧縮機１に吸入される。
【００７０】
冷凍室６冷却中に冷蔵室４の温度検知手段が予め設定された所定の温度を超えていることを検知すると、第二の電動弁１１を閉止し同時に第二の電動ファン１４を停止する（Ｔ２）。
【００７１】
所定時間、第一の電動弁１０と第二の電動弁１１を閉止し冷媒の流れを遮断する（Ｔ２〜Ｔ３）。
【００７２】
所定時間経過後、第一の電動弁１０を開放し第一の電動ファン１３を作動する（Ｔ３）。
【００７３】
冷媒は、第一の電動弁１０を経て第一のキャピラリ７に至る。その後、第一のキャピラリ７で第一のサクションライン１８と熱交換しながら減圧されて第一の蒸発器３に至る。第一の電動ファン１３の作動により冷蔵室４内の空気と積極的に熱交換されて冷媒は第一の蒸発器３内で蒸発気化し熱交換された空気は比較的低温の空気となって吐出され冷蔵室４を冷却する。気化した冷媒は、第一のサクションライン１８を経て圧縮機１に吸入される。
【００７４】
冷蔵室４冷却中に冷蔵室４の温度検知手段が予め設定された所定の温度より低いことを検知すると、第一の電動弁１０を閉止し同時に第一の電動ファン１３を停止し、同時に第二の電動弁１１を開放し第二の電動ファン１４を作動し、冷凍室６の冷却を開始する（Ｔ４）。
【００７５】
以上の動作を繰り返し、冷媒の流れを切り替えることにより、冷蔵室４と冷凍室６を交互に冷却し、冷蔵室４と冷凍室６の温度検知手段が共に予め設定された所定の温度より低いことを検知すると、圧縮機を停止する（Ｔ５）。
【００７６】
第一の電動弁１０が閉止であり第二の電動弁１１が開放である、第二の蒸発器５に冷媒が流入する冷凍室６冷却状態から、第一の電動弁１０が開放し第二の電動弁１１が閉止となる、第一の蒸発器３に冷媒が流入する冷蔵室４冷却状態に冷媒の流れが切り替わる時、第一の電動弁１０と第二の電動弁１１を所定時間閉止し（Ｔ２〜Ｔ３）、冷媒の流れが完全に遮断された状態で圧縮機を運転するために圧縮機内の圧力が通常運転時と比較してかなり低圧となり、第二の蒸発器５内に滞留していた冷媒を第二の蒸発器５から追い出すことが可能となる。
【００７７】
その結果、第一の電動弁１０が開放となり冷蔵室４冷却状態に切り替わった時（Ｔ３）、速やかに第一の蒸発器３に冷媒が供給されるので冷媒循環量不足にならず、効率よく冷蔵室４を冷却することが可能となる。
【００７８】
なお、例えば可燃性冷媒を用いる場合には上記の結果より冷媒を効率よく利用することができるので冷蔵室４冷却時に必要冷媒量が増加することがなく冷媒量を削減でき、冷媒漏洩時の危険性を小さくすることが可能となる。
【００７９】
（実施の形態２）
実施例１と同一構成についてはその詳細な説明を省略し、同一符号を付す。
【００８０】
第一の電動弁１０が閉止であり第二の電動弁１１が開放である。第二の蒸発器５に冷媒が流入する冷凍室６冷却状態から、第一の電動弁１０が開放し第二の電動弁１１が閉止となる、第一の蒸発器３に冷媒が流入する冷蔵室４冷却状態に冷媒の流れが切り替わる時、第一の電動弁１０と第二の電動弁１１を共に閉止する時間（Ｔ２〜Ｔ３）を制御するタイマーＴを備えた制御手段Ｃ２を設ける。
【００８１】
以上のように構成された冷蔵庫について、冷蔵室４冷却から冷凍室６冷却に切り替わる時の、第一の電動弁１０と第二の電動弁１１の動作のタイミングについて図２のタイムチャートをもとに説明する。
【００８２】
冷凍室６冷却中に冷蔵室４の温度検知手段が予め設定された所定の温度を超えていることを検知すると、第二の電動弁１１を閉止し同時に第二の電動ファン１４を停止する（Ｔ２）。
【００８３】
タイマーＴにより所定時間、第一の電動弁１０と第二の電動弁１１を閉止し冷媒の流れを遮断する（Ｔ２〜Ｔ３）。
【００８４】
所定時間経過後、第一の電動弁１０を開放し第一の電動ファン１３を作動し、冷蔵室４の冷却を開始する（Ｔ３）。
【００８５】
タイマーＴによる制御は、安価であり、制御手段が複雑でなく、且つ容易に設定時間を変更することができるので、最も簡単に冷媒の流れを制御することが可能となる。
【００８６】
（実施の形態３）
図４は本発明の実施例３における冷蔵庫の概略図、図５は本発明の実施例３のタイムチャートである。
【００８７】
実施例１と同一構成についてはその詳細な説明を省略し、同一符号を付す。
【００８８】
第二の蒸発器５の配管温度を検出する温度検知手段Ｔｈ３を設け、第一の電動弁１０が閉止であり第二の電動弁１１が開放である。第二の蒸発器５に冷媒が流入する冷凍室６冷却状態から、第一の電動弁１０が開放し第二の電動弁１１が閉止となる、第一の蒸発器３に冷媒が流入する冷蔵室４冷却状態に冷媒の流れが切り替わる時、第一の電動弁１０と第二の電動弁１１を前記温度検知手段により所定の温度設定値以上を検知するまで閉止した後、第一の電動弁１０を開放し冷蔵室４の冷却を開始する制御手段Ｃ３を設ける。
【００８９】
以上のように構成された冷蔵庫について、冷蔵室４冷却から冷凍室６冷却に切り替わる時の、第一の電動弁１０と第二の電動弁１１の動作のタイミングについて図５のタイムチャートをもとに説明する。
【００９０】
冷凍室６冷却中、第二の蒸発器５に流入した冷媒は冷凍室６内の空気と積極的に熱交換を行い、比較的低い温度（ｔ１）で蒸発気化している（Ｔ６〜Ｔ７）。
【００９１】
冷凍室６冷却中に冷蔵室４の温度検知手段が予め設定された所定の温度を超えていることを検知すると、第二の電動弁１１を閉止する（Ｔ７）。
【００９２】
第一の電動弁１０と第二の電動弁１１を共に閉止し、冷媒の流れが完全に遮断された状態で圧縮機１を運転すると第二の蒸発器５内に滞留していた気液二相状態の冷媒は、圧力が下がるために蒸発しながら第二の蒸発器５から圧縮機１へ移動する。
【００９３】
その結果、第二の蒸発器に冷媒が残留している間は、第二の蒸発器５の配管温度は冷凍室温度（ｔ２）より低温となる。そして、冷媒の残留量が少なくなるにつれて上昇し冷凍室温度（ｔ２）に近づく（Ｔ７〜Ｔ８）。
【００９４】
第二の蒸発器５の配管温度が、例えば冷凍室温度（ｔ２）と等しくなった時、第二の蒸発器５内に滞留していた冷媒がほとんどなくなったと判断し、第一の電動弁１０を開放し冷蔵室４の冷却を開始する（Ｔ８）。
【００９５】
これにより、冷凍室６冷却から冷蔵室４冷却に切り替わる時、最も効率よく第二の蒸発器５内に滞留していた冷媒を追い出すことができ、冷蔵室４冷却開始時に、速やかに第一の蒸発器３に冷媒を供給できるので冷媒循環量不足にならず、さらに効率よく冷蔵室４を冷却することが可能となる。
【００９６】
（実施の形態４）
図６は本発明の実施例４における冷蔵庫の概略図、図７は本発明の実施例４のタイムチャートである。
【００９７】
実施例１と同一構成についてはその詳細な説明を省略し、同一符号を付す。
【００９８】
圧縮機１に流入する冷媒の圧力を検出する圧力検知手段（Ｐ）を設け、第一の電動弁１０が閉止であり第二の電動弁１１が開放である。第二の蒸発器５に冷媒が流入する冷凍室６冷却状態から、第一の電動弁１０が開放し第二の電動弁１１が閉止となる。第一の蒸発器３に冷媒が流入する冷蔵室４冷却状態に冷媒の流れが切り替わる時、第一の電動弁１０と第二の電動弁１１を前記圧力検知手段により所定の圧力設定値以下を検知するまで閉止した後、第一の電動弁１０を開放し冷蔵室４の冷却を開始する制御手段Ｃ４を設ける。
【００９９】
以上のように構成された冷蔵庫について、冷蔵室４冷却から冷凍室６冷却に切り替わる時の、第一の電動弁１０と第二の電動弁１１の動作のタイミングについて図７のタイムチャートをもとに説明する。
【０１００】
冷凍室６冷却中、圧縮機１に流入する冷媒の圧力は比較的低圧（ｐ１）である（Ｔ９〜Ｔ１０）。
【０１０１】
冷凍室６冷却中に冷蔵室４の温度検知手段が予め設定された所定の温度を超えていることを検知すると、第二の電動弁１１を閉止する（Ｔ１０）。
【０１０２】
第一の電動弁１０と第二の電動弁１１を共に閉止し、冷媒の流れを完全に遮断された状態で圧縮機１を運転すると圧縮機１に流入する冷媒の圧力は急速に低下し、最終的に０ＭＰａに近づく。しかし、この状態で圧縮機１の運転を繰り返すと圧縮機１に損傷をきたす恐れがあるので、圧縮機１に流入する冷媒の圧力検知手段が例えば０．０２ＭＰａ以下を検知した時、第一の電動弁１０を開放し冷蔵室４の冷却を開始する。
【０１０３】
これにより、冷凍室６冷却から冷蔵室４冷却に切り替わる時に圧縮機１にかかる負担を低減でき、圧縮機１の損傷を防ぐことが可能となる。
【０１０４】
（実施の形態５）
図８は本発明の実施例５における冷蔵庫の概略図、図９は本発明の実施例５のタイムチャートである。
【０１０５】
実施例１と同一構成についてはその詳細な説明を省略し、同一符号を付す。
【０１０６】
第一の電動弁１０が閉止であり第二の電動弁１１が開放である、第二の蒸発器５に冷媒が流入する冷凍室６冷却状態から、第一の電動弁１０が開放し第二の電動弁１１が閉止となる、第一の蒸発器３に冷媒が流入する冷蔵室４冷却状態に冷媒の流れが切り替わる時、第二の電動弁１１を閉止し、第一の電動弁１０を断続的に所定時間開閉した後、第一の電動弁１０を開放し冷蔵室４の冷却を開始する制御手段Ｃ５を設ける。
【０１０７】
以上のように構成された冷蔵庫について、冷蔵室４冷却から冷凍室６冷却に切り替わる時の、第一の電動弁１０と第二の電動弁１１の動作のタイミングについて、圧縮機１に流入する冷媒の圧力変化を参考に図９のタイムチャートをもとに説明する。
【０１０８】
冷凍室６冷却中、圧縮機１に流入する冷媒の圧力は比較的低圧（ｐ３）である（Ｔ１２〜１３）。
【０１０９】
冷凍室６冷却中に冷蔵室４の温度検知手段が予め設定された所定の温度を超えていることを検知すると、第二の電動弁１１を閉止する（Ｔ１３）。
【０１１０】
第一の電動弁１０と第二の電動弁１１を共に閉止し、冷媒の流れが完全に遮断された状態で圧縮機１を運転すると圧縮機１に流入する冷媒の圧力は低下を始める（Ｔ１３〜１４）。
【０１１１】
所定時間経過後、第一の電動弁１０を開放する。この時、圧縮機１に流入する圧力は運転中の圧力（ｐ３）から（ｐ４）に低下している（Ｔ１４）。
【０１１２】
第一の電動弁１０を開放すると、閉塞していた冷凍サイクルが開となり冷媒が循環し始めるので圧縮機１に流入する冷媒の圧力は上昇する（Ｔ１４〜Ｔ１５）。
【０１１３】
所定時間経過後、第一の電動弁１０を閉止する。この時、圧縮機１に流入する冷媒の圧力は（ｐ４）から（ｐ５）にやや上昇している（Ｔ１５）。
【０１１４】
第一の電動弁１０を閉止すると、冷媒の流れが完全に遮断された状態で圧縮機１を運転するために圧縮機１に流入する冷媒の圧力は再び低下を始める。
【０１１５】
以上の動作を繰り返し、所定時間経過後、第一の電動弁１０を開放し冷蔵室４の冷却を開始する。この時の、圧縮機１に流入する冷媒の圧力は冷凍室６冷却中の圧力（ｐ３）から（ｐ６）に低下している（Ｔ１７）。
【０１１６】
これにより、冷凍室６冷却から冷蔵室４冷却に切り替わる時に圧縮機１に流入する冷媒の圧力を段階的に低下させることができるので、圧力の急低下による圧縮機１への負担を低減し、損傷を防ぐことが可能となる。
【０１１７】
また、その結果、第一の電動弁１０と第二の電動弁１１を共に完全に閉止して第二の蒸発器５内に滞留した冷媒を追い出す手段と比較して、より長い間第二の蒸発器５内に滞留した冷媒を追い出すことができるので、さらに効率よく冷蔵室４の冷却を行うことが可能となる。
【０１１８】
（実施の形態６）
図１０は本発明の実施例６における冷蔵庫の概略図、図１１は本発明の実施例６のタイムチャートである。
【０１１９】
実施例１と同一構成についてはその詳細な説明を省略し、同一符号を付す。
【０１２０】
冷蔵室４と冷凍室６の図示しない温度検知手段が共に所定の温度設定値以下を検知すると、第一の電動弁１０と第二の電動弁１１を閉止し、所定時間経過後圧縮機１を停止させ、圧縮機停止中は第一の電動弁１０と第二の電動弁１１を常に閉止する制御手段Ｃ６を設ける。
【０１２１】
以上のように構成された冷蔵庫について、圧縮機が停止する時の第一の電動弁１０と第二の電動弁１１の動作について、図１１のタイムチャートをもとに説明する。
【０１２２】
例えば冷凍室６冷却中、冷蔵室４と冷凍室６の図示しない温度検知手段が共に所定の温度設定値以下を検知すると、第一の電動弁１０と第二の電動弁１１を閉止する（Ｔ１８）。
【０１２３】
所定時間経過後、圧縮機１を停止する。（Ｔ１９）。
【０１２４】
圧縮機１停止中、第一の電動弁１０と第二の電動弁１１は常に閉止する（Ｔ１９〜Ｔ２０）。
【０１２５】
圧縮機１停止中に、例えば冷凍室６の温度検知手段Ｔｈ２が所定の温度設定値以上を検知すると、圧縮機１を作動させ、同時に第二の電動弁１１を開放し冷凍室６の冷却を開始する（Ｔ２０）。
【０１２６】
圧縮機１を停止する前
に、第一の電動弁１０と第二の電動弁１１を閉止し、冷媒の流れが完全に遮断された状態で圧縮機１を所定時間運転するので、圧縮機１に流入する冷媒の圧力は低下し第一の蒸発器３と第二の蒸発器５に滞留している冷媒を圧縮機側へ追い出すことが可能となる。
【０１２７】
また、圧縮機１停止中は冷凍室の温度が例えば約−１８℃と最も低いために冷凍室６内に配設された第二の蒸発器５の圧力が冷凍サイクル内で最も低圧となり、凝縮器２内の高圧冷媒が第二の蒸発器５内へ移動し滞留するので冷却開始時に例えば第二の蒸発器５に速やかに冷媒を供給できず効率低下の原因となっていたが、圧縮機１停止中は第一の電動弁１０と第二の電動弁１１を常に閉止するために第一の蒸発器３と第二の蒸発器５への冷媒の移動は妨げられ、圧縮機１起動時に速やかに例えば第二の蒸発器に冷媒を供給することができるので冷媒循環量不足にならず、効率よく冷凍室を冷却することが可能となる。
【０１２８】
尚、実施例においては第一の流路制御手段と第二の流路制御手段とがそれぞれ独立して説明したが、三方弁を用いても同様の効果が得られる。
【０１２９】
【発明の効果】
本発明は、以上説明したような形態で実施され、以下に記載されるような効果を奏する。
【０１３０】
第一の流路制御手段が閉止であり第二の流路制御手段が開放で、第二の蒸発器に可燃性冷媒が流入する状態から、第一の流路制御手段が開放し第二の流路制御手段が閉となり、第一の蒸発器に可燃性冷媒が流入する状態に冷媒の流れが切り替わる時、第一の流路制御手段と第二の流路制御手段をともに所定時間閉止し、冷媒の流れが完全に遮断された状態で圧縮機を運転するために圧縮機内の圧力が通常運転時と比較してかなり低圧となり、第二の蒸発器内に滞留していた可燃性冷媒を第二の蒸発器から追い出すことが可能となる。
【０１３１】
その結果、第一の流路制御手段が開放となり切り替わった時、速やかに第一の蒸発器に冷媒が供給されるので冷媒循環量不足にならず、効率よく冷蔵室を冷却することが可能となる。
【０１３２】
また、可燃性冷媒を効率よく利用することができるので必要冷媒量が増加することがなく冷媒量を削減でき、冷媒漏洩時の危険性を小さくすることが可能となる。
【０１３３】
また、第二の蒸発器の配管温度を検出する温度検知手段を設け、この温度検知手段により所定の温度設定値以上を検知するまで閉止した後、第一の流路制御手段を開放して冷却を開始することにより、最も効率よく第二の蒸発器内に滞留していた冷媒を追い出すことができ、冷却開始時に、速やかに第一の蒸発器に冷媒を供給できるので冷媒循環量不足にならず、さらに効率よく冷却することが可能となる。
【０１３４】
また、第一の流路制御手段が閉止であり第二の流路制御手段が開放である第二の蒸発器５に冷媒が流入する状態から、第一の流路制御手段が開放し第二の流路制御手段が閉止となる第一の蒸発器３に冷媒が流入する冷却状態に冷媒の流れが切り替わる時、第二の流路制御手段を閉止し、第一の流路制御手段を断続的に所定時間開閉した後、第一の流路制御手段を開放し冷却を開始することにより、切り替わる時に圧縮機に流入する冷媒の圧力を段階的に低下させることができるので、圧力の急低下による圧縮機への負担を低減し、損傷を防ぐことが可能となる。
【０１３５】
また、その結果、第一の流路制御手段と第二の流路制御手段を共に閉止して第二の蒸発器内に滞留した冷媒を追い出す手段と比較して、より長い間第二の蒸発器内に滞留した冷媒を追い出すことができるので、さらに効率よく冷却を行うことが可能となる。
【０１３６】
また、冷蔵室と冷凍室を備えた箱体と、圧縮機、凝縮器、この凝縮器からの冷媒を分流する第一の流路制御手段と第二の流路制御手段、前記第一の流路制御手段の下流側に連結された第一の減圧手段、この第一の減圧手段と連結された第一の蒸発器、前記第二の流路制御手段の下流側に連結された第二の減圧手段、及び、この第二の減圧手段と連結された第二の蒸発器を備えた冷凍サイクルとを有し、前記第一の冷却器により前記冷蔵室を冷却し、前記第二の冷却器により前記冷凍室を冷却するものであって、前記冷媒を可燃性冷媒とし、前記圧縮機は、吸入冷媒が圧縮機内空間に放出される低圧容器型でかつインバーターによる回転数制御で冷媒循環量を変化できる能力可変型であり、前記第一の流路制御手段と第二の流路制御手段とを機械室内に配設する三方弁で構成したものであって、前記冷蔵室及び前記冷凍室の温度検知手段がともに設定温度以下になったとき、前記三方弁を閉として前記圧縮機を停止し、前記圧縮機の停止中は前記三方弁を閉としたまま前記冷媒の前記第一、第二の蒸発器への移動を防止する冷蔵庫であるので冷媒を効率よく利用することができるので可燃性冷媒の冷媒量を削減でき、冷媒漏洩時の危険性を小さくすることが可能となる。
【０１３７】
また、第一の流路制御手段と第二の流路制御手段を閉止し、所定時間経過後圧縮機を停止させることにより、第一の蒸発器と第二の蒸発器に滞留している冷媒を圧縮機側へ追い出すことが可能となる。
【図面の簡単な説明】
【図１】本発明の請求項１の実施例における冷蔵庫の概略図
【図２】本発明の請求項１と請求項２の実施例における冷蔵庫のタイムチャート
【図３】本発明の請求項２の実施例における冷蔵庫の概略図
【図４】本発明の請求項３の実施例における冷蔵庫の概略図
【図５】本発明の請求項３の実施例における冷蔵庫のタイムチャート
【図６】本発明の請求項４の実施例における冷蔵庫の概略図
【図７】本発明の請求項４の実施例における冷蔵庫のタイムチャート
【図８】本発明の請求項５の実施例における冷蔵庫の概略図
【図９】本発明の請求項５の実施例における冷蔵庫のタイムチャート
【図１０】本発明の請求項６の実施例における冷蔵庫の概略図
【図１１】本発明の請求項６の実施例における冷蔵庫のタイムチャート
【図１２】従来の冷蔵庫の概略図
【符号の説明】
１圧縮機
２凝縮器
３第一の蒸発器
５第二の蒸発器
７第一の減圧手段（キャピラリ）
８第二の減圧手段（キャピラリ）
１０第一の流路制御手段（電動弁）
１１第二の流路制御手段（電動弁）
Ｃ１，Ｃ２，Ｃ３，Ｃ４，Ｃ５，Ｃ６制御手段
Ｔタイマー
Ｔｈ３温度検知手段
Ｐ圧力検知手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooling system used for a refrigerator or the like.
[0002]
[Prior art]
FIG. 12 shows a schematic diagram of a refrigerator disclosed in Japanese Patent Publication No. 62-22396 as an example of a conventional cooling cycle and a refrigerator.
[0003]
1 is a constant speed compressor, 2 is a condenser, 3 is a first evaporator disposed in the refrigerator compartment 4, and 5 is a second evaporator disposed in the freezer compartment 6.
[0004]
Reference numeral 7 denotes a first decompression means (capillary) disposed upstream of the first evaporator 3 for cooling the refrigerator in the refrigerant circuit, and 8 denotes a second evaporator 5 for cooling the freezer. Reference numeral 9 denotes a second pressure reducing means (capillary) disposed upstream of the refrigerant circuit, and reference numeral 9 denotes a check valve provided downstream of the second evaporator 5 for cooling the freezing compartment.
[0005]
Reference numeral 10 denotes a first opening / closing valve provided on the downstream side of the first evaporator 3 in the refrigerant circuit, and reference numeral 11 denotes a second opening / closing valve provided on the upstream side of the second capillary 8 in the refrigerant circuit.
[0006]
The operation of the conventional refrigerator configured as described above will be described below.
[0007]
The operation of the refrigeration cycle is performed as follows. First, the refrigerant compressed by the compressor 1 is condensed and liquefied in the condenser 2. The condensed refrigerant is decompressed by the first capillary 7 or the second capillary 8, flows into the first evaporator 3 and the second evaporator 5, respectively, is evaporated and vaporized, and then returns to the compressor 1. Inhaled.
[0008]
Each room is cooled by the heat exchange between the first evaporator 3, the second evaporator 5, and the air in the refrigerator compartment 4 and the freezer compartment 6, which have become relatively low in temperature by evaporating the refrigerant.
[0009]
The cooling operation of the refrigerator is performed as follows by temperature detecting means and control means of each room (not shown).
[0010]
When each of the temperature detecting means of the refrigerator compartment 4 and the freezing compartment 6 detects a temperature rise equal to or higher than a predetermined value, the compressor 1 is started and the refrigeration cycle is operated. The first on-off valve 10 is opened and the second on-off valve 11 is closed until the temperature detecting means of the refrigerator compartment 4 becomes lower than a predetermined value.
[0011]
Thereby, the refrigerant does not flow into the second evaporator 5 but flows only to the first evaporator 3. At this time, the evaporating temperature of the refrigeration cycle is set to -5 to 0 ° C. when the temperature of the refrigerating compartment 4 is about 5 ° C. The compressor can be operated with a coefficient of performance of .5 times.
[0012]
When the refrigerator compartment 4 is cooled and the temperature drops, and the temperature detecting means detects the temperature below a predetermined value, the first on-off valve 10 is closed and the second on-off valve 11 is opened.
[0013]
Thereby, the refrigerant flows into the second evaporator 5, and the freezing compartment 6 is cooled. At this time, the evaporating temperature of the refrigerating cycle is cooled at a normal evaporating temperature while the temperature of the freezing room is set at about −18 ° C.
[0014]
As described above, since the refrigerant supply time to the evaporator is distributed to the refrigerating compartment 4 and the freezing compartment 6 to alternately cool the refrigerating compartment 4, the refrigerant is independently supplied to the first evaporator when the refrigerating compartment 4 is cooled. By circulating, a high evaporation temperature (−5 to 0 ° C.) is possible without the need for a low-pressure pressure regulating valve, the compression ratio of the compressor 1 can be reduced, and operation is performed with a high coefficient of performance to improve efficiency. .
[0015]
Further, the check valve 9 prevents the refrigerant from flowing into the second evaporator 5 because the evaporation temperature during the cooling of the refrigerator compartment 4 is high.
[0016]
In addition, when cooling the freezing room 6, the amount of the refrigerant may be smaller than during the cooling of the refrigerator compartment 4, so that the amount of the refrigerant is usually excessive. However, the first on-off valve 10 is provided downstream of the first evaporator 3 and is closed, so that the refrigerant can be stored in the first evaporator 3 and the amount of the refrigerant can be adjusted.
[0017]
[Problems to be solved by the invention]
In the above-mentioned conventional refrigerator, the refrigerating room 4 and the freezing room 6 are distributed with the supply time of the refrigerant to the evaporator, and are cooled alternately and repeatedly. It is possible to operate at a relatively high evaporation temperature (−5 to 0 ° C.) with a good coefficient of performance.
[0018]
However, when the refrigerator compartment 4 is cooled, the temperature of the freezer compartment 6 is low, for example, about −18 ° C., so that the pressure of the second evaporator 5 disposed in the freezer compartment 6 becomes low, so that the second evaporation The refrigerant retained in the vessel 5 is less likely to flow out of the second evaporator 5. As a result, a sufficient amount of refrigerant is not supplied to the first evaporator 3, and the amount of circulating refrigerant becomes insufficient, resulting in a decrease in efficiency.
[0019]
Due to the above factors, the required amount of refrigerant increases, and when a flammable refrigerant is used, there is a large risk of refrigerant leakage and a problem.
[0020]
Further, since the temperature of the freezing compartment 6 is the lowest, for example, about −18 ° C. while the compressor 1 is stopped, the pressure of the second evaporator 5 disposed in the freezing compartment 6 becomes the lowest in the refrigeration cycle, Since the high-pressure refrigerant in the condenser moves to the second evaporator 5 and stays therein, the liquid refrigerant flows into the compressor 1 when the compressor 1 is started, which not only causes the compressor 1 to fail but also causes the compressor 1 to fail. At the time of startup, a time delay occurs until the refrigerant is supplied stably to the evaporator, which causes a reduction in efficiency.
[0021]
The present invention solves the above-described conventional problems, and provides a refrigerator capable of saving energy by reducing the amount of refrigerant and improving the efficiency of a cooling system that performs cooling by switching between a refrigerator compartment and a freezer compartment. The purpose is to:
[0022]
[Means for Solving the Problems]
The cooling system according to claim 1 of the present invention includes a compressor, a condenser, a first flow path control means and a second flow path control means for dividing a refrigerant from the condenser, A first decompression means connected to the flow path control means, a first evaporator connected to the first pressure reduction means, and a second decompression means connected to the second flow path control means And a second evaporator connected to the second decompression means, and a temperature detection means for detecting a pipe temperature of the second evaporator, the refrigerant as a flammable refrigerant, the first From the state where the flow path of the flow path control means is closed and the flow path of the second flow path control means is open and the refrigerant flows into the second evaporator, the flow path of the first flow path control means The flow path is open and the flow path of the second flow path control means is closed, and the flow of the refrigerant is switched to a state in which the refrigerant flows into the first evaporator. Come, the first, the second flow path control valveAfter closing, when the temperature detecting means for detecting the pipe temperature of the second evaporator rises to a predetermined temperatureAnd control means for opening the flow path of the first flow path control means.
[0023]
Thereby, when switching from the cooling state of the freezing compartment into which the refrigerant has flowed into the second evaporator to the cooling state of the refrigerator compartment into which the refrigerant has flowed into the first evaporator, the two flow control means are closed for a predetermined time. Therefore, since the compressor is operated in a state where the flow of the refrigerant is completely shut off, the pressure in the compressor becomes lower than that in the normal operation, so that the refrigerant remaining in the second evaporator is removed. It can be driven out of the second evaporator.
[0024]
As a result, efficient operation can be achieved without shortage of the circulation amount of the refrigerant.
[0025]
In addition, the efficient use of refrigerant can reduce the amount of refrigerant compared to the conventional method,ofThe danger due to refrigerant leakage can be reduced.
[0027]
AlsoWhen the compressor is operated in a state where the flow of the refrigerant is completely shut off, the refrigerant in the gas-liquid two-layer state that has stayed in the second evaporator evaporates due to a decrease in pressure, and the second evaporator evaporates. Since the refrigerant moves to the compressor, while the refrigerant remains in the second evaporator, the pipe temperature of the second evaporator becomes low.
[0028]
That is, the refrigerant can be quickly supplied to the cooling of the first evaporator, so that the refrigerant circulation amount does not become insufficient.
[0029]
Claims of the invention2The cooling system described above is connected to a compressor, a condenser, a first flow path control means, a second flow path control means, and a first flow path control means for dividing a refrigerant from the condenser. First decompression means, a first evaporator connected to the first decompression means, a second decompression means connected to the second flow path control means, and a second decompression means A second evaporator connected to the means, wherein the refrigerant is a flammable refrigerant, the flow path of the first flow path control means is closed, and the flow path of the second flow path control means is open. From the state where the refrigerant is flowing into the second evaporator, the flow path of the first flow path control means is open and the flow path of the second flow path control means is closed and the first flow path is closed. When switching the flow of the refrigerant to a state where the refrigerant flows into the evaporator, the first flow control valve is intermittently closed for a predetermined time, and then the first flow is controlled. Those having a control means for the passage of the control means open.
[0030]
By intermittently operating the compressor in this manner, the pressure of the refrigerant flowing through the compressor can be reduced in a stepwise manner, so that damage to the compressor due to a sudden drop in pressure can be prevented.
[0031]
Further, efficient use of the refrigerant can reduce the amount of the refrigerant as compared with the related art, so that danger due to refrigerant leakage of the flammable refrigerant can be reduced.
[0032]
Claims of the invention3The refrigerator according to the present invention includes a box having a refrigerator compartment and a freezer compartment, a compressor, a condenser, a first flow path control means and a second flow path control means for dividing the refrigerant from the condenser, One flow path control meansDownstream ofA first decompression means connected to the first evaporator connected to the first decompression means, a second decompression means connected to the downstream side of the second flow path control means, and Having a refrigeration cycle with a second evaporator connected to the second decompression means,The first cooler cools the refrigerator compartment, the second cooler cools the freezer compartment, wherein the refrigerant is a flammable refrigerant,The compressor is a low-pressure container type in which the suction refrigerant is discharged into the internal space of the compressor, and is a variable capacity type capable of changing the refrigerant circulation amount by controlling the rotation speed by an inverter. Flow path control means and machine room installedComposed of three-way valveWhen both the temperature detection means of the refrigerator compartment and the freezer compartment fall below a set temperature,Three-way valveTo close the compressor and stop the compressorPrevents the refrigerant from moving to the first and second evaporators while the three-way valve is closedTo do.
[0033]
As a result, when the compressor is stopped, the pressure in the second evaporator becomes the lowest in the refrigeration cycle because the temperature of the freezer is the lowest, and the high-pressure refrigerant in the condenser moves into the second evaporator. Since the refrigerant stayed at the start of cooling, the refrigerant could not be quickly supplied to the second evaporator, causing a decrease in efficiency.However, during the stop of the compressor, the first motor-operated valve and the second motor-operated valve were closed. The movement of the refrigerant to the first evaporator and the second evaporator is prevented, and the refrigerant can be supplied to the second evaporator quickly at the time of starting the compressor. It becomes possible to cool the freezer compartment.
[0034]
In the refrigerator according to claim 4 of the present invention, before stopping the compressor, the first flow path control means and the second flow path control means are closed, and the flow of the refrigerant is completely shut off. Since the compressor is operated for a predetermined time, the pressure of the refrigerant flowing into the compressor decreases, and the refrigerant remaining in the first evaporator and the second evaporator can be expelled to the compressor side.
[0036]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention described in claim 1 of the present inventionA compressor, a condenser, a first flow path control means and a second flow path control means for dividing the refrigerant from the condenser, and a first decompression connected to the first flow path control means. Means, a first evaporator connected to the first pressure reducing means, a second pressure reducing means connected to the second flow path control means, and a second pressure reducing means connected to the second pressure reducing means. A second evaporator, and a temperature detecting means for detecting a pipe temperature of the second evaporator, wherein the refrigerant is a flammable refrigerant, the flow path of the first flow path control means is closed and the second From the state where the flow path of the flow path control means is open and the refrigerant is flowing into the second evaporator, the flow path of the first flow path control means is open and the second flow control When the flow path of the means is closed and the flow of the refrigerant is switched to a state where the refrigerant flows into the first evaporator, the first and second flow path control valves are closed. Later, the temperature detecting means for detecting the piping temperature of the second evaporator when raised to a predetermined temperature, comprising a control means for the flow path of the first flow path control means and to openIt is characterized by the following.
[0041]
Thus, when the flow paths of the first flow path control means and the second flow path control means are closed and the compressor is operated in a state in which the flow of the refrigerant is completely shut off, the refrigerant stays in the second evaporator. The refrigerant in the gas-liquid two-phase state that has been moved from the second evaporator to the compressor while evaporating due to a decrease in pressure, so that while the refrigerant remains in the second evaporator, the second The pipe temperature of the evaporator is lower than the freezing room temperature. Then, as the residual amount of the refrigerant decreases, the temperature rises and approaches the freezing room temperature.
[0042]
When the pipe temperature of the second evaporator becomes equal to, for example, the freezing room temperature, it is determined that the refrigerant remaining in the second evaporator has almost disappeared, and the first flow path control means is opened to refrigerate. Start cooling the chamber.
[0043]
Thereby, when the operation of the evaporator is switched, the refrigerant that has stayed in the second evaporator can be driven out most efficiently, and the refrigerant can be supplied to the first evaporator quickly, so that the refrigerant circulation amount becomes insufficient. In addition, it is possible to operate more efficiently.
[0044]
Of the present inventionClaim 2The invention described in the above is connected to a compressor, a condenser, a first flow path control means, a second flow path control means for dividing the refrigerant from the condenser, and the first flow path control means First decompression means, a first evaporator connected to the first decompression means, a second decompression means connected to the second flow path control means, and a second decompression means A second evaporator connected to the means, wherein the refrigerant is a flammable refrigerant, the flow path of the first flow path control means is closed, and the flow path of the second flow path control means is open. From the state where the refrigerant is flowing into the second evaporator, the flow path of the first flow path control means is open and the flow path of the second flow path control means is closed and the first flow path is closed. When switching the flow of the refrigerant to a state where the refrigerant flows into the evaporator, after the first flow path control valve is intermittently closed for a predetermined time, the first flow path control is performed. Those having a control means for the flow path of the stage and opened.
[0045]
This makes it possible to gradually reduce the pressure of the refrigerant flowing into the compressor when switching from freezer compartment cooling to refrigerator compartment cooling, thereby reducing the load on the compressor due to a sudden drop in pressure and preventing damage. Becomes possible.
[0046]
Further, as a result, the second evaporating operation is performed for a longer time as compared with the case where both the first flow path control means and the second flow path control means are closed and the refrigerant that has accumulated in the second evaporator is expelled. Since the refrigerant staying in the vessel can be expelled, it is possible to more efficiently cool the refrigerator compartment.
[0047]
In addition, since the refrigerant can be used efficiently from the above results, the amount of the flammable refrigerant can be reduced, and the risk of refrigerant leakage can be reduced.
[0048]
Of the present inventionClaim 3The invention described in the above, a box having a refrigerator compartment and a freezer compartment, a compressor, a condenser, a first flow path control means and a second flow path control means for diverting the refrigerant from the condenser, First flow path control meansDownstream ofA first decompression means connected to the first evaporator connected to the first decompression means, a second decompression means connected to the downstream side of the second flow path control means, and Having a refrigeration cycle with a second evaporator connected to the second decompression means,The first cooler cools the refrigerator compartment, the second cooler cools the freezer compartment, wherein the refrigerant is a flammable refrigerant,The compressor is a low-pressure container type in which the suction refrigerant is discharged into the internal space of the compressor, and is a variable capacity type capable of changing the refrigerant circulation amount by controlling the rotation speed by an inverter. Flow path control means and machine room installedComposed of three-way valveWhen both the temperature detection means of the refrigerator compartment and the freezer compartment fall below a set temperature,Three-way valveTo close the compressor and stop the compressorDuring the stop of the operation, the refrigerant is prevented from moving to the first and second evaporators while the three-way valve is closed.It is a refrigerator.
[0049]
While the compressor is stopped, the pressure in the second evaporator becomes the lowest in the refrigeration cycle because the temperature of the freezing room is the lowest, and the high-pressure refrigerant in the condenser moves into the second evaporator and stays there, so cooling is performed. At the start, the refrigerant could not be quickly supplied to the second evaporator, causing a decrease in efficiency.However, during the stop of the compressor, the first evaporator and the second The movement of the refrigerant to the evaporator and the second evaporator is prevented, and the refrigerant can be supplied to the second evaporator quickly at the time of starting the compressor. It is possible to do.
In addition, since the refrigerant can be used efficiently, the amount of the flammable refrigerant can be reduced, and the risk of leakage of the refrigerant can be reduced.
[0050]
Of the present inventionClaim 4In the invention described in the above, before stopping the compressor, the first flow path control means and the second flow path control means are closed, and the compressor is operated for a predetermined time while the flow of the refrigerant is completely shut off. Therefore, the pressure of the refrigerant flowing into the compressor decreases, and the refrigerant remaining in the first evaporator and the second evaporator can be expelled to the compressor side.
[0052]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Detailed descriptions of the same components as those of the conventional example are omitted, and the same reference numerals are given.
[0053]
(Embodiment 1)
FIG. 1 is a schematic diagram of a refrigerator in Embodiment 1 of the present invention, and FIG. 2 is a time chart of the embodiment.
[0054]
Reference numeral 20 denotes a refrigerator box, in which a refrigerating compartment 4 which is a relatively high temperature compartment is disposed in an upper portion, and a relatively low temperature freezing compartment 6 is disposed in a lower portion, and the periphery is insulated with a heat insulating material such as urethane. It is composed. Loading and unloading of stored items such as food is performed via an insulated door (not shown).
[0055]
The refrigerator compartment 4 is usually set at 3 to 5 ° C. for refrigerated storage, but may be set at a slightly lower temperature, for example, -3 to 0 ° C. to improve freshness. In some cases, it is possible for the user to freely switch the temperature setting as described above. In some cases, the temperature may be set slightly higher, for example, around 10 ° C. to preserve wine and root vegetables.
[0056]
The freezer compartment 6 is normally set at -22 to -18 ° C for freezing storage, but may be set at a lower temperature, for example, -30 to -25 ° C, for improving freshness.
[0057]
The refrigeration cycle 12 sequentially connects the compressor 1, the condenser 2, the first motor-operated valve 10 as the first flow path control means, the first capillary 7 as the first pressure reducing means, and the first evaporator 3. The second motor-operated valve 11, which is the second flow path control means, and the second pressure-reducing means are arranged in parallel with the first motor-operated valve 10, the first capillary 7, and the first evaporator 3. The second capillary 8 and the second evaporator 5 are connected.
[0058]
The first evaporator 3 is disposed in the refrigerator compartment 4, for example, on the inner surface of the refrigerator compartment, and near the first evaporator 3, the air in the compartment of the refrigerator compartment 4 is passed and circulated. Of the electric fan 13 is provided.
[0059]
The second evaporator 5 is disposed in the freezing compartment 6, for example, on the inner surface of the freezing compartment, and circulates air in the compartment of the freezing compartment 6 through the second evaporator 5 in the vicinity. A second electric fan 14 is provided.
[0060]
The compressor 1, the condenser 2, the first motor-operated valve 10, and the second motor-operated valve 11 are used to reduce the number of pipe connection points in the refrigerator box 20 from the viewpoint of improving safety when a flammable refrigerant is used. It is arranged in the machine room 15.
[0061]
The refrigerant returning from each evaporator passes through the compressor suction pipe 16, is discharged into the internal space of the compressor 1, and is then discharged through the compressor discharge pipe 17.
[0062]
Further, the compressor 1 is of a variable capacity type in which the amount of refrigerant circulated can be controlled by, for example, controlling the rotation speed by an inverter to change the refrigeration capacity.
[0063]
The refrigerating compartment 4 and the freezing compartment 6 are provided with temperature detecting means Th1 and Th2, for example, thermistors for detecting the temperature in the compartment, and the variable capacity compressor 1, the first electric valve 10, and the second A control unit C1 for controlling the electric valve 11, the first electric fan 13, and the second electric fan 14 is provided. A check valve 21 is interposed between the second evaporator 5 and the compressor 1 to prevent the refrigerant from flowing backward.
[0064]
Here, the basic operation of the first motor-operated valve, the second motor-operated valve, the first fan, and the second fan will be described.
[0065]
During the operation of the compressor, the first motor-operated valve 10 performs an opening operation when the temperature detecting means of the refrigerator compartment 4 exceeds a predetermined temperature, and when the temperature detecting means is lower than the predetermined temperature. Perform the closing operation. Similarly, the first electric fan 13 operates when the temperature detecting means of the refrigerator compartment 4 exceeds a predetermined temperature, and stops when the temperature is lower than the predetermined temperature. .
[0066]
Further, during the operation of the compressor, the second motor-operated valve 11 performs an opening operation when the temperature detecting means of the refrigerator compartment 4 is lower than a predetermined temperature, and when the temperature detecting means is higher than a predetermined temperature. Perform the closing operation. Similarly, the second electric fan 14 operates when the temperature detecting means of the refrigerator compartment 4 is lower than a predetermined temperature, and stops when the temperature detecting means is higher than the predetermined temperature.
[0067]
With respect to the refrigerator configured as described above, the cooling timing of the refrigerator compartment 4 and the freezer compartment 6 will be described based on the time chart of FIG.
[0068]
When the temperature in the freezing compartment 6 rises while the compressor is stopped, the temperature detecting means of the freezing compartment 6 detects that the temperature exceeds a predetermined temperature. The control means receives this signal, operates the compressor 1 and the second electric fan 14, opens the second electric valve 11, and closes the first electric valve (T1).
[0069]
The high-temperature and high-pressure refrigerant discharged by the operation of the compressor 1 releases heat in the condenser 2 to be condensed and liquefied, and reaches the second capillary 8 via the second electric valve 11. Then, the pressure is reduced while exchanging heat with the second suction line 19 in the second capillary 8, and reaches the second evaporator 5. The heat is actively exchanged with the air in the freezing room 6 by the operation of the second electric fan 14, the refrigerant evaporates and evaporates in the second evaporator 5, and the heat-exchanged air is discharged as lower-temperature air. Then, the freezing room 6 is cooled. The vaporized refrigerant is sucked into the compressor 1 via the second suction line 19.
[0070]
When the temperature detecting means of the refrigerator compartment 4 detects that the temperature exceeds a predetermined temperature during the cooling of the freezer compartment 6, the second electric valve 11 is closed and the second electric fan 14 is stopped at the same time ( T2).
[0071]
For a predetermined time, the first motor-operated valve 10 and the second motor-operated valve 11 are closed to shut off the flow of the refrigerant (T2 to T3).
[0072]
After a lapse of a predetermined time, the first electric valve 10 is opened and the first electric fan 13 is operated (T3).
[0073]
The refrigerant reaches the first capillary 7 via the first electric valve 10. Thereafter, the pressure is reduced while exchanging heat with the first suction line 18 in the first capillary 7 and reaches the first evaporator 3. The operation of the first electric fan 13 actively exchanges heat with the air in the refrigerator compartment 4, the refrigerant evaporates and evaporates in the first evaporator 3, and the heat exchanged air becomes relatively low-temperature air. The discharged refrigerator cools the refrigerator compartment 4. The vaporized refrigerant is sucked into the compressor 1 via the first suction line 18.
[0074]
When the temperature detecting means of the refrigerator compartment 4 detects that the temperature is lower than a predetermined temperature during the cooling of the refrigerator compartment 4, the first electric valve 10 is closed and the first electric fan 13 is stopped at the same time. The second electric valve 11 is opened, the second electric fan 14 is operated, and cooling of the freezing compartment 6 is started (T4).
[0075]
By repeating the above operation and switching the flow of the refrigerant, the refrigerating compartment 4 and the freezing compartment 6 are alternately cooled, and both the temperature detecting means of the refrigerating compartment 4 and the freezing compartment 6 are lower than a predetermined temperature. Is detected, the compressor is stopped (T5).
[0076]
When the first electric valve 10 is closed and the second electric valve 11 is open, the first electric valve 10 is opened and the second electric valve 10 is opened from the cooling state of the freezing chamber 6 in which the refrigerant flows into the second evaporator 5. When the flow of the refrigerant is switched to the cooling state of the refrigerating compartment 4 in which the refrigerant flows into the first evaporator 3, the first electric valve 10 and the second electric valve 11 are closed for a predetermined time. However, since the compressor is operated in a state where the flow of the refrigerant is completely shut off (T2 to T3), the pressure in the compressor becomes considerably lower than that in the normal operation and stays in the second evaporator 5. The used refrigerant can be driven out of the second evaporator 5.
[0077]
As a result, when the first motor-operated valve 10 is opened and switched to the cooling state of the refrigerator compartment 4 (T3), the refrigerant is quickly supplied to the first evaporator 3, so that the amount of circulating refrigerant does not become insufficient, and the efficiency is improved. The refrigerator compartment 4 can be cooled.
[0078]
In the case of using a flammable refrigerant, for example, the refrigerant can be efficiently used based on the above results. Therefore, the amount of refrigerant can be reduced without increasing the required amount of refrigerant when cooling the refrigerator compartment 4, and the risk of refrigerant leakage can be reduced. It is possible to reduce the performance.
[0079]
(Embodiment 2)
Detailed descriptions of the same components as those of the first embodiment are omitted, and the same reference numerals are given.
[0080]
The first motor-operated valve 10 is closed and the second motor-operated valve 11 is open. From the cooling state of the freezing compartment 6 in which the refrigerant flows into the second evaporator 5, the first electric valve 10 is opened and the second electric valve 11 is closed, and refrigeration in which the refrigerant flows into the first evaporator 3 When the flow of the refrigerant is switched to the cooling state of the chamber 4, a control means C2 having a timer T for controlling a time (T2 to T3) for closing both the first electric valve 10 and the second electric valve 11 is provided.
[0081]
Regarding the refrigerator configured as described above, the operation timing of the first motor-operated valve 10 and the second motor-operated valve 11 when switching from the cooling of the refrigerator compartment 4 to the cooling of the freezer compartment 6 will be described with reference to the time chart of FIG. Will be described.
[0082]
When the temperature detecting means of the refrigerator compartment 4 detects that the temperature exceeds a predetermined temperature during the cooling of the freezer compartment 6, the second electric valve 11 is closed and the second electric fan 14 is stopped at the same time ( T2).
[0083]
The first motor-operated valve 10 and the second motor-operated valve 11 are closed for a predetermined time by the timer T to shut off the flow of the refrigerant (T2 to T3).
[0084]
After a lapse of a predetermined time, the first electric valve 10 is opened, the first electric fan 13 is operated, and the cooling of the refrigerator compartment 4 is started (T3).
[0085]
The control by the timer T is inexpensive, the control means is not complicated, and the set time can be easily changed, so that the flow of the refrigerant can be controlled most easily.
[0086]
(Embodiment 3)
FIG. 4 is a schematic diagram of a refrigerator according to the third embodiment of the present invention, and FIG. 5 is a time chart of the third embodiment of the present invention.
[0087]
Detailed descriptions of the same components as those of the first embodiment are omitted, and the same reference numerals are given.
[0088]
A temperature detecting means Th3 for detecting a pipe temperature of the second evaporator 5 is provided, the first electric valve 10 is closed, and the second electric valve 11 is open. From the cooling state of the freezing compartment 6 in which the refrigerant flows into the second evaporator 5, the first electric valve 10 is opened and the second electric valve 11 is closed, and refrigeration in which the refrigerant flows into the first evaporator 3 When the flow of the refrigerant is switched to the cooling state of the chamber 4, the first motor-operated valve 10 and the second motor-operated valve 11 are closed until the temperature detecting means detects a temperature equal to or higher than a predetermined temperature set value. A control means C3 for opening the refrigerator compartment 10 and starting the cooling of the refrigerator compartment 4 is provided.
[0089]
Regarding the refrigerator configured as described above, the timing of the operation of the first motor-operated valve 10 and the second motor-operated valve 11 when switching from the cooling of the refrigerator compartment 4 to the cooling of the freezer compartment 6 will be described with reference to the time chart of FIG. Will be described.
[0090]
During cooling of the freezing compartment 6, the refrigerant flowing into the second evaporator 5 actively exchanges heat with the air in the freezing compartment 6, and evaporates at a relatively low temperature (t1) (T6 to T7). .
[0091]
When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds a predetermined temperature during cooling of the freezing compartment 6, the second electric valve 11 is closed (T7).
[0092]
When the compressor 1 is operated in a state in which the first motor-operated valve 10 and the second motor-operated valve 11 are both closed and the flow of the refrigerant is completely shut off, the gas-liquid mixture retained in the second evaporator 5 The refrigerant in the phase moves from the second evaporator 5 to the compressor 1 while evaporating due to a decrease in pressure.
[0093]
As a result, while the refrigerant remains in the second evaporator, the pipe temperature of the second evaporator 5 is lower than the freezing room temperature (t2). The temperature rises as the residual amount of the refrigerant decreases and approaches the freezing room temperature (t2) (T7 to T8).
[0094]
When the pipe temperature of the second evaporator 5 becomes equal to, for example, the freezing room temperature (t2), it is determined that the refrigerant remaining in the second evaporator 5 has almost disappeared, and the first electric valve 10 And the cooling of the refrigerator compartment 4 is started (T8).
[0095]
Thereby, when switching from the freezing room 6 cooling to the refrigerating room 4 cooling, the refrigerant that has stayed in the second evaporator 5 can be expelled most efficiently, and the first refrigerating room 4 cooling is immediately started when the refrigerating room 4 cooling starts. Since the refrigerant can be supplied to the evaporator 3, the amount of circulating refrigerant does not become insufficient, and the refrigerator compartment 4 can be cooled more efficiently.
[0096]
(Embodiment 4)
FIG. 6 is a schematic diagram of a refrigerator according to the fourth embodiment of the present invention, and FIG. 7 is a time chart of the fourth embodiment of the present invention.
[0097]
Detailed descriptions of the same components as those of the first embodiment are omitted, and the same reference numerals are given.
[0098]
A pressure detecting means (P) for detecting the pressure of the refrigerant flowing into the compressor 1 is provided. The first electric valve 10 is closed and the second electric valve 11 is open. From the cooling state of the freezing compartment 6 in which the refrigerant flows into the second evaporator 5, the first electric valve 10 is opened and the second electric valve 11 is closed. When the flow of the refrigerant is switched to the cooling state of the refrigerator compartment 4 in which the refrigerant flows into the first evaporator 3, the first electric valve 10 and the second electric valve 11 are set to a predetermined pressure set value or less by the pressure detecting means. After closing until the detection, a control means C4 for opening the first motor-operated valve 10 and starting cooling of the refrigerator compartment 4 is provided.
[0099]
Regarding the refrigerator configured as described above, the operation timing of the first motor-operated valve 10 and the second motor-operated valve 11 when switching from the cooling of the refrigerator compartment 4 to the cooling of the freezer compartment 6 will be described with reference to the time chart of FIG. Will be described.
[0100]
During the cooling of the freezing compartment 6, the pressure of the refrigerant flowing into the compressor 1 is relatively low (p1) (T9 to T10).
[0101]
When the temperature detecting means of the refrigerating compartment 4 detects that the temperature exceeds a predetermined temperature while cooling the freezing compartment 6, the second motor-operated valve 11 is closed (T10).
[0102]
When the first motor-operated valve 10 and the second motor-operated valve 11 are both closed and the compressor 1 is operated in a state where the flow of the refrigerant is completely shut off, the pressure of the refrigerant flowing into the compressor 1 rapidly decreases, Eventually, it approaches 0 MPa. However, if the operation of the compressor 1 is repeated in this state, the compressor 1 may be damaged. Therefore, when the pressure detecting means of the refrigerant flowing into the compressor 1 detects, for example, 0.02 MPa or less, the first The electric valve 10 is opened to start cooling the refrigerator compartment 4.
[0103]
This reduces the load on the compressor 1 when switching from cooling the freezer compartment 6 to cooling the refrigerator compartment 4, and prevents damage to the compressor 1.
[0104]
(Embodiment 5)
FIG. 8 is a schematic diagram of a refrigerator according to the fifth embodiment of the present invention, and FIG. 9 is a time chart of the fifth embodiment of the present invention.
[0105]
Detailed descriptions of the same components as those of the first embodiment are omitted, and the same reference numerals are given.
[0106]
When the first electric valve 10 is closed and the second electric valve 11 is open, the first electric valve 10 is opened and the second electric valve 10 is opened from the cooling state of the freezing chamber 6 in which the refrigerant flows into the second evaporator 5. When the flow of the refrigerant is switched to the cooling state of the refrigerating chamber 4 in which the refrigerant flows into the first evaporator 3, the second electric valve 11 is closed, and the first electric valve 10 is closed. After opening and closing intermittently for a predetermined time, a control means C5 for opening the first motor-operated valve 10 and starting cooling of the refrigerator compartment 4 is provided.
[0107]
Regarding the refrigerator configured as described above, the timing of the operation of the first motor-operated valve 10 and the second motor-operated valve 11 when switching from the cooling in the refrigerator compartment 4 to the cooling in the freezer compartment 6 will be described. This will be described with reference to the time chart of FIG.
[0108]
During cooling of the freezing compartment 6, the pressure of the refrigerant flowing into the compressor 1 is relatively low (p3) (T12 to T13).
[0109]
When the temperature detecting means of the refrigerator compartment 4 detects that the temperature exceeds the predetermined temperature during the cooling of the freezer compartment 6, the second motor-operated valve 11 is closed (T13).
[0110]
When the first motor-operated valve 10 and the second motor-operated valve 11 are both closed and the compressor 1 is operated in a state where the flow of the refrigerant is completely shut off, the pressure of the refrigerant flowing into the compressor 1 starts to decrease (T13). ~ 14).
[0111]
After a lapse of a predetermined time, the first motor-operated valve 10 is opened. At this time, the pressure flowing into the compressor 1 has decreased from the operating pressure (p3) to (p4) (T14).
[0112]
When the first motor-operated valve 10 is opened, the closed refrigeration cycle is opened and the refrigerant starts to circulate, so that the pressure of the refrigerant flowing into the compressor 1 increases (T14 to T15).
[0113]
After a lapse of a predetermined time, the first motor-operated valve 10 is closed. At this time, the pressure of the refrigerant flowing into the compressor 1 has slightly increased from (p4) to (p5) (T15).
[0114]
When the first motor-operated valve 10 is closed, the pressure of the refrigerant flowing into the compressor 1 in order to operate the compressor 1 in a state where the flow of the refrigerant is completely shut off starts to decrease again.
[0115]
The above operation is repeated, and after a lapse of a predetermined time, the first motor-operated valve 10 is opened to start cooling the refrigerator compartment 4. At this time, the pressure of the refrigerant flowing into the compressor 1 decreases from the pressure (p3) during cooling of the freezing compartment 6 to (p6) (T17).
[0116]
Thereby, the pressure of the refrigerant flowing into the compressor 1 when switching from the cooling of the freezing compartment 6 to the cooling of the refrigerator compartment 4 can be reduced step by step, so that the load on the compressor 1 due to a sudden drop in pressure can be reduced. Damage can be prevented.
[0117]
As a result, the first motor-operated valve 10 and the second motor-operated valve 11 are both completely closed to expel the refrigerant remaining in the second evaporator 5 for a longer period of time. Since the refrigerant staying in the evaporator 5 can be expelled, the refrigerating compartment 4 can be cooled more efficiently.
[0118]
(Embodiment 6)
FIG. 10 is a schematic diagram of a refrigerator according to the sixth embodiment of the present invention, and FIG. 11 is a time chart of the sixth embodiment of the present invention.
[0119]
Detailed descriptions of the same components as those of the first embodiment are omitted, and the same reference numerals are given.
[0120]
When the temperature detecting means (not shown) of the refrigerating compartment 4 and the freezing compartment 6 both detect a predetermined temperature or less, the first motor-operated valve 10 and the second motor-operated valve 11 are closed, and the compressor 1 is operated after a predetermined time has elapsed. A control means C6 is provided to stop the compressor and always close the first motor-operated valve 10 and the second motor-operated valve 11 while the compressor is stopped.
[0121]
The operation of the first motor-operated valve 10 and the second motor-operated valve 11 when the compressor stops in the refrigerator configured as described above will be described with reference to the time chart of FIG.
[0122]
For example, during cooling of the freezer compartment 6, if both the temperature detecting means (not shown) of the refrigerating compartment 4 and the freezer compartment 6 detect a predetermined temperature or less, the first electric valve 10 and the second electric valve 11 are closed (T18). ).
[0123]
After a lapse of a predetermined time, the compressor 1 is stopped. (T19).
[0124]
While the compressor 1 is stopped, the first electric valve 10 and the second electric valve 11 are always closed (T19 to T20).
[0125]
If, for example, the temperature detecting means Th2 of the freezing room 6 detects a temperature equal to or higher than a predetermined temperature while the compressor 1 is stopped, the compressor 1 is operated, and at the same time, the second electric valve 11 is opened to cool the freezing room 6. Start (T20).
[0126]
Before stopping compressor 1
Since the first motor-operated valve 10 and the second motor-operated valve 11 are closed and the compressor 1 is operated for a predetermined time in a state where the flow of the refrigerant is completely shut off, the pressure of the refrigerant flowing into the compressor 1 becomes It is possible to expel the refrigerant that has decreased and stays in the first evaporator 3 and the second evaporator 5 to the compressor side.
[0127]
Further, while the compressor 1 is stopped, the temperature of the freezing compartment is the lowest, for example, about -18 ° C., so that the pressure of the second evaporator 5 disposed in the freezing compartment 6 becomes the lowest in the refrigerating cycle, and The high-pressure refrigerant in the evaporator 2 moves into the second evaporator 5 and stays therein, so that it is not possible to quickly supply the refrigerant to the second evaporator 5 at the start of cooling, for example. During one stop, the movement of the refrigerant to the first evaporator 3 and the second evaporator 5 is prevented because the first motor-operated valve 10 and the second motor-operated valve 11 are always closed. For example, since the refrigerant can be quickly supplied to the second evaporator, the amount of circulating refrigerant does not become insufficient, and the freezing room can be efficiently cooled.
[0128]
In the embodiment, the first flow path control means and the second flow path control means have been described independently, but the same effect can be obtained by using a three-way valve.
[0129]
【The invention's effect】
The present invention is implemented in the form described above, and has the following effects.
[0130]
The first flow path control means is closed, the second flow path control means is open, and the second evaporatorFlammableFrom the state where the refrigerant flows, the first flow path control means is opened and the second flow path control means is closed, and the first evaporator is closed.FlammabilityWhen the flow of the refrigerant is switched to a state in which the refrigerant flows, both the first flow path control means and the second flow path control means are closed for a predetermined time, and the compressor is operated in a state where the flow of the refrigerant is completely shut off. The pressure inside the compressor became considerably lower than that during normal operation, and remained in the second evaporator.FlammabilityThe refrigerant can be driven out of the second evaporator.
[0131]
As a result, when the first flow path control means is opened and switched, the refrigerant is quickly supplied to the first evaporator, so that the refrigerant circulation amount is not insufficient, and the refrigerator compartment can be efficiently cooled. Become.
[0132]
Also,FlammabilitySince the refrigerant can be used efficiently, the amount of the refrigerant can be reduced without increasing the required refrigerant amount, and the danger at the time of refrigerant leakage can be reduced.
[0133]
Further, a temperature detecting means for detecting a pipe temperature of the second evaporator is provided. After the temperature detecting means is closed until a predetermined temperature set value or more is detected, the first flow path controlling means is opened and cooled. By starting, the refrigerant that has accumulated in the second evaporator can be driven out most efficiently, and when the cooling starts, the refrigerant can be quickly supplied to the first evaporator, so that if the refrigerant circulation amount is insufficient, And cooling can be performed more efficiently.
[0134]
Further, from the state where the refrigerant flows into the second evaporator 5 in which the first flow path control means is closed and the second flow path control means is open, the first flow path control means is opened and the second flow path is opened. When the flow of the refrigerant is switched to a cooling state in which the refrigerant flows into the first evaporator 3 in which the first flow path control means is closed, the second flow path control means is closed, and the first flow path control means is intermittently operated. After opening and closing for a predetermined period of time, by opening the first flow path control means and starting cooling, the pressure of the refrigerant flowing into the compressor at the time of switching can be reduced stepwise, so that the pressure drops sharply. This reduces the load on the compressor and prevents damage.
[0135]
Further, as a result, the second evaporator is closed for a longer time as compared with the means for closing both the first flow path control means and the second flow path control means to expel the refrigerant accumulated in the second evaporator. Since the refrigerant staying in the vessel can be expelled, cooling can be performed more efficiently.
[0136]
Also,A box having a refrigerator compartment and a freezer compartment, a compressor, a condenser, first flow path control means and second flow path control means for dividing the refrigerant from the condenser, and the first flow path control A first decompression means connected to the downstream side of the means, a first evaporator connected to the first decompression means, and a second decompression means connected to the downstream side of the second flow path control means And a refrigeration cycle including a second evaporator connected to the second pressure reducing means, wherein the first refrigerator cools the refrigerator compartment, and the second refrigerator cools the refrigerator. The refrigerant is used for cooling a freezing room, wherein the refrigerant is a flammable refrigerant, and the compressor is a low-pressure container type in which a suction refrigerant is discharged into a space inside the compressor, and can change a refrigerant circulation amount by controlling a rotation speed by an inverter. A variable capacity type, wherein the first flow path control means and the second flow path control means When the temperature detecting means of the refrigerator compartment and the freezing compartment both become lower than a set temperature, the compressor is stopped by closing the three-way valve, and the compressor is stopped. While the three-way valve is closed, the refrigerator is a refrigerator that prevents the refrigerant from moving to the first and second evaporators while the three-way valve is closed. Can be reduced, and the danger at the time of refrigerant leakage can be reduced.
[0137]
Also,The first flow path control means and the second flow path control means are closed, and the pressure By stopping the compressor, it is possible to expel the refrigerant remaining in the first evaporator and the second evaporator to the compressor side.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a refrigerator according to an embodiment of the present invention.
FIG. 2 is a time chart of the refrigerator according to the first and second embodiments of the present invention.
FIG. 3 is a schematic view of a refrigerator according to a second embodiment of the present invention.
FIG. 4 is a schematic view of a refrigerator according to a third embodiment of the present invention.
FIG. 5 is a time chart of a refrigerator according to the third embodiment of the present invention.
FIG. 6 is a schematic view of a refrigerator according to a fourth embodiment of the present invention.
FIG. 7 is a time chart of the refrigerator according to the fourth embodiment of the present invention.
FIG. 8 is a schematic view of a refrigerator according to a fifth embodiment of the present invention.
FIG. 9 is a time chart of the refrigerator in the embodiment of claim 5 of the present invention.
FIG. 10 is a schematic view of a refrigerator according to a sixth embodiment of the present invention.
FIG. 11 is a time chart of a refrigerator according to the sixth embodiment of the present invention.
FIG. 12 is a schematic diagram of a conventional refrigerator.
[Explanation of symbols]
1 compressor
2 condenser
3 First evaporator
5 Second evaporator
7 First decompression means (capillary)
8 Second decompression means (capillary)
10 First flow path control means (motorized valve)
11 Second flow control means (motorized valve)
C1, C2, C3, C4, C5, C6 control means
T timer
Th3 temperature detection means
P Pressure detection means

Claims

A compressor, a condenser, a first flow path control means and a second flow path control means for dividing the refrigerant from the condenser, and a first decompression connected to the first flow path control means. Means, a first evaporator connected to the first pressure reducing means, a second pressure reducing means connected to the second flow path control means, and a second pressure reducing means connected to the second pressure reducing means. A second evaporator, and a temperature detecting means for detecting a pipe temperature of the second evaporator, wherein the refrigerant is a flammable refrigerant, the flow path of the first flow path control means is closed and the second From the state where the flow path of the flow path control means is open and the refrigerant is flowing into the second evaporator, the flow path of the first flow path control means is open and the second flow control When the flow path of the means is closed and the flow of the refrigerant is switched to a state where the refrigerant flows into the first evaporator, the first and second flow path control valves are closed. Later, when the temperature detecting means for detecting the pipe temperature of the second evaporator rises to a predetermined temperature, a control means for opening the flow path of the first flow path control means is provided. Cooling system.

A compressor, a condenser, a first flow path control means and a second flow path control means for dividing the refrigerant from the condenser, and a first decompression connected to the first flow path control means. Means, a first evaporator connected to the first pressure reducing means, a second pressure reducing means connected to the second flow path control means, and a second pressure reducing means connected to the second pressure reducing means. A second evaporator, wherein the refrigerant is a flammable refrigerant, the flow path of the first flow path control means is closed, and the flow path of the second flow path control means is open, From the state where the refrigerant flows into the vessel, the flow path of the first flow path control means is opened and the flow path of the second flow path control means is closed, and the refrigerant flows into the first evaporator. When the flow of the refrigerant is switched to a state in which the first flow path control means is intermittently closed for a predetermined time, the flow path of the first flow path control means is opened. Cooling system characterized by comprising a control unit that.

A box having a refrigerator compartment and a freezer compartment, a compressor, a condenser, first flow path control means and second flow path control means for diverting the refrigerant from the condenser, and the first flow path control A first decompression means connected to the downstream side of the means, a first evaporator connected to the first decompression means, and a second decompression means connected to the downstream side of the second flow path control means And a refrigeration cycle including a second evaporator connected to the second pressure reducing means, wherein the first refrigerator cools the refrigerator compartment, and the second refrigerator cools the refrigerator. A compressor for cooling a freezer, wherein the refrigerant is a flammable refrigerant, and the compressor is a low-pressure container type in which a suction refrigerant is discharged into a space inside the compressor, and can change a refrigerant circulation amount by controlling a rotation speed by an inverter. A variable capacity type, wherein the first flow path control means and the second flow path control means Be those constructed by three-way valve arranged, when the temperature detecting means of the refrigerating chamber and the freezing chamber are both equal to or less than the set temperature, the compressor stops the three-way valve is closed, the compressor A refrigerator that prevents the refrigerant from moving to the first and second evaporators while the three-way valve is closed while the operation is stopped .

4. The refrigerator according to claim 3, wherein the compressor is stopped a predetermined time after the first and second flow path control means are both closed.