JP2004085105A

JP2004085105A - Refrigerator

Info

Publication number: JP2004085105A
Application number: JP2002247860A
Authority: JP
Inventors: Hitoshi Aoki; 青木　均史; Nobuhisa Koumoto; 甲元　伸央; Hirotaka Kakinuma; 柿沼　裕貴; Junichi Kubota; 久保田　順一; Hiroshi Mukoyama; 向山　洋; Akira Sugawara; 菅原　晃; Haruhisa Yamazaki; 山崎　晴久
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 2002-08-27
Filing date: 2002-08-27
Publication date: 2004-03-18
Anticipated expiration: 2022-08-27
Also published as: JP3995562B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerator optimum for using a cooling medium with the state varied at a super-critical region at a high pressure side of a refrigeration cycle and not liquefied. <P>SOLUTION: The refrigerator is provided with a compressor (16) provided with a primary compression mechanism for compressing the cooling medium from a flowing-in port (16d) at a first stage and delivering it from a delivery port (16a) at the first stage and a secondary compression mechanism for compressing the cooling medium from a flowing-in port (16b) at a second stage and delivering it from the delivery port at the second stage. The refrigerator is provided with a refrigeration cycle at the first stage starting from a delivery port at the first stage and returning the flowing-in port at the second stage through a primary air-cooling heat exchange part (17a); a refrigeration cycle at the second stage starting from the delivery port and returning to the flowing-in port at the first stage through a secondary air-cooling heat exchange part (17b), pressure reduction devices (22, 23) and a cooling unit (24); and a bedewing prevention pipe (19) for preventing bedewing on an opening of the heat insulation box (1). Further, a drain evaporation pipe (26) is provided at a downstream of the delivery port at the first stage. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、庫内の貯蔵物を冷蔵する冷蔵庫に関する。
【０００２】
【従来の技術】
従来の冷蔵庫は、庫内が冷凍サイクルの冷却器で冷却されており、この庫内に貯蔵物を貯蔵している。冷凍サイクルの冷媒は、一般的にはフロン系冷媒が用いられ、凝縮器で液化している。したがって、この凝縮器において、冷媒は略一定の温度（すなわち、凝縮温度）となる。
【０００３】
【発明が解決しようとする課題】
ところで、近年、フロン系冷媒の使用を削減する方向であり、冷蔵庫においても、フロン系冷媒以外の冷媒（たとえば、二酸化炭素など）の使用が考慮されている。この様な冷媒を使用すると、冷凍サイクルの高圧側において、冷媒が超臨界域で状態変化し液化しないことがあり、減圧装置における冷媒の膨張を大きくするために、コンプレッサの圧縮比を高くしている。この様に、圧縮比を高くすると、圧縮された冷媒の温度は大きく上昇する。そして、この冷媒の熱は、外部に廃棄されており、殆ど有効利用されていない。
【０００４】
本発明は、以上のような課題を解決するためのもので、冷凍サイクルの高圧側において超臨界域で状態変化し液化しない状態の冷媒を使用するのに最適な冷蔵庫を提供することを目的としている。
【０００５】
【課題を解決するための手段】
本出願の請求項１記載の冷蔵庫は、外郭が断熱箱体（１）で構成されるとともに、その前面開口が断熱扉で開閉可能に閉じられる冷蔵庫において、一段目の流入口（１６ｄ）からの冷媒を圧縮して一段目の吐出口（１６ａ）から吐出する一次圧縮機構および、二段目の流入口（１６ｂ）からの冷媒を圧縮して二段目の吐出口（１６ｃ）から吐出する二次圧縮機構を具備するコンプレッサ（１６）と、このコンプレッサの一段目の吐出口から、コンプレッサの一次圧縮機構で圧縮されて高温・高圧となったガス状冷媒が空冷される一次空冷熱交換部（１７ａ）を経て、コンプレッサの二段目の流入口に戻る一段目の冷凍サイクルと、前記コンプレッサの二段目の吐出口から、二次圧縮機構で圧縮されて高温・高圧となったガス状冷媒が超臨界域で状態変化しながら空冷される二次空冷熱交換部（１７ｂ）、減圧装置（２２，２３）および、この減圧装置により減圧されて低温となった冷媒で庫内を冷却する冷却器（２４）を経て、コンプレッサの一段目の流入口に戻る二段目の冷凍サイクルと、前記冷却器に付着した霜を融解させる除霜手段（２９）と、この除霜手段により融解したドレン水が流入するドレン容器（３２）と、冷凍サイクルの冷媒が流れてドレン容器のドレン水を蒸発させるドレン蒸発パイプ（２６）とを備え、前記ドレン蒸発パイプが、前記一段目の冷凍サイクルのコンプレッサの一段目の吐出口から一次空冷熱交換部への冷媒回路中に設けられていることを特徴とする。
【０００６】
請求項２記載の冷蔵庫は、請求項１記載の冷蔵庫において、前記断熱箱体の間口の露付を防止する露付防止パイプ（１９）が、冷凍サイクルの二次空冷熱交換部から減圧装置への冷媒回路中に設けられていることを特徴とする。
【０００７】
請求項３記載の冷蔵庫は、請求項１または２記載の冷蔵庫において、ドレン容器内の水の有無を検知する水検知手段（３６）、前記ドレン蒸発パイプから一次空冷熱交換部への冷媒回路中に設けられ、冷媒の流れを切り換えて一次空冷熱交換部をバイパスするバイパス切換弁（２７）、および、水検知手段がドレン容器内の水を検知した際には、バイパス切換弁をバイパス側に切り換える制御手段（４１）を備えていることを特徴とする。
【０００８】
請求項４記載の冷蔵庫は、請求項１または２記載の冷蔵庫において、一次空冷熱交換部の冷媒を空冷する一次空冷熱交換部用送風機（５１）、二次空冷熱交換部の冷媒を空冷する二次空冷熱交換部用送風機（５２）、ドレン容器内の水の有無を検知する水検知手段、および、水検知手段がドレン容器内の水を検知した際には、一次空冷熱交換部用送風機を停止させる制御手段を備えていることを特徴とする。
【０００９】
請求項５記載の冷蔵庫は、外郭が断熱箱体で構成されるとともに、その前面開口が断熱扉で開閉可能に閉じられる冷蔵庫において、冷媒を圧縮するコンプレッサ、このコンプレッサで圧縮されて高温・高圧となったガス状冷媒が超臨界域で状態変化しながら送風機で空冷される空冷熱交換器（１７）、減圧装置および、この減圧装置により減圧されて低温となった冷媒で庫内を冷却する冷却器を順次冷媒配管（２１）で環状に接続してコンプレッサに戻る冷凍サイクルと、前記冷却器に付着した霜を融解させる除霜手段と、この除霜手段により融解したドレン水が流入するドレン容器と、冷凍サイクルの冷媒が流れてドレン容器のドレン水を蒸発させるドレン蒸発パイプとを備え、前記ドレン蒸発パイプは、コンプレッサの下流側の冷媒回路に配置され、コンプレッサからの高温・高圧の冷媒が流れることを特徴とする。
【００１０】
請求項６記載の冷蔵庫は、請求項５記載の冷蔵庫において、断熱箱体の間口の露付を防止する露付防止パイプが、冷凍サイクルの空冷熱交換器から減圧装置への冷媒回路中に設けられていることを特徴とする。
【００１１】
請求項７記載の冷蔵庫は、請求項５または６記載の冷蔵庫において、ドレン容器内の水の有無を検知する水検知手段、前記ドレン蒸発パイプから空冷熱交換器への冷媒回路中に設けられ、冷媒の流れを切り換えて空冷熱交換器をバイパスするバイパス切換弁（４７）、および、水検知手段がドレン容器内の水を検知した際には、バイパス切換弁をバイパス側に切り換える制御手段を備えていることを特徴とする。
【００１２】
請求項８記載の冷蔵庫は、外郭が断熱箱体で構成されるとともに、その前面開口が断熱扉で開閉可能に閉じられる冷蔵庫において、一段目の流入口からの冷媒を圧縮して一段目の吐出口から吐出する一次圧縮機構および、二段目の流入口からの冷媒を圧縮して二段目の吐出口から吐出する二次圧縮機構を具備するコンプレッサと、このコンプレッサの一段目の吐出口から、コンプレッサの一次圧縮機構で圧縮されて高温・高圧となったガス状冷媒が空冷される一次空冷熱交換部を経て、コンプレッサの二段目の流入口に戻る一段目の冷凍サイクルと、前記コンプレッサの二段目の吐出口から、二次圧縮機構で圧縮されて高温・高圧となったガス状冷媒が超臨界域で状態変化しながら空冷される二次空冷熱交換部、減圧装置および、この減圧装置により減圧されて低温となった冷媒で庫内を冷却する冷却器を経て、コンプレッサの一段目の流入口に戻る二段目の冷凍サイクルと、前記冷却器に付着した霜を融解させる除霜手段と、この除霜手段により融解したドレン水が流入するドレン容器と、二段目の冷凍サイクルのコンプレッサの二段目の吐出口から二次空冷熱交換部への冷媒回路中に設けられ、冷凍サイクルの冷媒が流れてドレン容器のドレン水を蒸発させるドレン蒸発パイプと、一次空冷熱交換部の冷媒を空冷する一次空冷熱交換部用送風機と、二次空冷熱交換部の冷媒を空冷する二次空冷熱交換部用送風機と、ドレン容器内の水の有無を検知する水検知手段と、水検知手段がドレン容器内の水を検知した際には、二次空冷熱交換部用送風機を停止させる制御手段とを備えていることを特徴とする。
【００１３】
【発明の実施の形態】
次に、本発明における冷蔵庫の実施の第１の形態を図１ないし図６を用いて説明する。図１は本発明にかかる冷蔵庫の実施の第１の形態の冷媒回路の説明図である。図２は図１の冷蔵庫の冷媒回路の具体例の図である。図３は図２における露付防止パイプの図である。図４は制御装置の入出力図である。図５は切換弁をバイパス側に切り換えた状態における実施の第１の形態の冷媒回路の説明図である。図６は切換弁の作動のフローチャートである。
【００１４】
家庭用冷蔵庫は、その外郭が断熱箱体１（図３参照）で構成されている。この断熱箱体１の内部空間すなわち庫内は、設定温度の異なる複数の部屋（この実施の形態では４室）に仕切られており、上側から冷蔵室６、野菜室７、冷凍室８および冷凍室９となっている。各冷却室６〜９の前面は開口し、この前面開口は断熱扉（図示せず）で開閉自在に閉じられている。また、冷凍室９の奥側は、機械室１１となっている。
【００１５】
機械室１１には、庫内を冷却するための機器、すなわち、二段圧縮式のコンプレッサ１６、空冷熱交換器１７、空冷熱交換器用送風機１８などが設けられている。コンプレッサ１６および空冷熱交換器１７などは、冷媒配管２１で接続されて冷凍サイクルを構成し、冷凍サイクルの冷媒としては、ＣＯ_２　（二酸化炭素）が用いられる。この冷凍サイクルは、図１に図示するように、コンプレッサ１６の一段目の吐出口１６ａから、順次、ドレン蒸発パイプ２６、空冷熱交換器１７の一次空冷熱交換部１７ａを通ってコンプレッサ１６の二段目の流入口１６ｂに戻る一段目のサイクルと、コンプレッサ１６の二段目の吐出口１６ｃから、順次、空冷熱交換器１７の二次空冷熱交換部１７ｂ、断熱箱体１の間口（前端面）に沿って配管されている露付防止パイプ１９、内部熱交換器２０の高圧側配管２０ａ、キャピラリーチューブ２２、電動膨張弁２３、冷却器２４、および、内部熱交換器２０の低圧側配管２０ｂから再びコンプレッサ１６の一段目の流入口１６ｄに戻る二段目のサイクルとを有している。
【００１６】
キャピラリーチューブ２２および電動膨張弁２３が減圧装置を構成している。また、内部熱交換器２０において、高圧側配管２０ａと低圧側配管２０ｂとは密着しており、高圧側配管２０ａの比較的高温の冷媒と、低圧側配管２０ｂの低温の冷媒とが熱交換をする。そして、コンプレッサ１６は、一段目の圧縮機構が、一段目の流入口１６ｄから流入した冷媒を圧縮して吐出口１６ａから吐出し、また、二段目の圧縮機構が、二段目の流入口１６ｂから流入した冷媒を圧縮して吐出口１６ｃから吐出する。さらに、一段目のサイクルにおけるドレン蒸発パイプ２６と一次空冷熱交換部１７ａとの間の冷媒回路中に、バイパス切換弁として三方切換弁２７が設けられ、この三方切換弁２７により、ドレン蒸発パイプ２６からの冷媒を一次空冷熱交換部１７ａに流す空冷熱交換側（図１に図示した状態）と、ドレン蒸発パイプ２６からの冷媒を一次空冷熱交換部１７ａをバイパスしてコンプレッサ１６の二段目の流入口１６ｂに戻すバイパス側（図５に図示した状態）とに切り換えることができる。
【００１７】
そして、冷却器２４は低温となり、周囲の空気の温度を低下させる。この冷却器２４の周囲の冷気は、庫内ファン２８が庫内に送風して循環させ、庫内を冷却する。この様にして、冷却器２４で庫内を冷却することができる。冷却器２４には霜が付着するため、除霜手段としての除霜ヒータ２９により、適宜時間間隔で霜を融解して除霜を行っている。冷却器２４からの除霜水であるドレン水は、露受皿３１で受けられ、この露受皿３１から落下してドレン容器３２に溜められる。このドレン容器３２には、前述のドレン蒸発パイプ２６が配管されており、ドレン容器３２のドレン水は、ドレン蒸発パイプ２６の高温の冷媒により加熱されて蒸発する。
【００１８】
また、コンプレッサ１６の吐出口１６ｃから電動膨張弁２３までが冷凍サイクルの高圧側で、電動膨張弁２３からコンプレッサ１６の流入口１６ｄまでが冷凍サイクルの低圧側となっている。そして、検出手段として、ドレン容器３２の水の有無を検知する水検知手段として水検知センサ３６や、庫内温度（この実施の形態では冷却室である冷凍室８の温度）を検出する冷却室温度検出手段としての庫内温度センサ３７が設けられている。
【００１９】
また、図４に図示するように、冷蔵庫には、制御装置４１が設けられており、この制御装置４１はマイコンなどで構成されている。そして、制御装置４１には、種々の電気部品が接続されているが、特に三方切換弁２７などの制御のための電気部品として、入力側に、水検知センサ３６および庫内温度センサ３７などが接続され、一方、出力側に、空冷熱交換器用送風機１８、電動膨張弁２３、庫内ファン２８、コンプレッサ１６、三方切換弁２７および除霜ヒータ２９などが接続されている。なお、制御装置４１の記憶部（ＲＯＭやＲＡＭなど）には種々の設定値が記憶されるとともに、図示しないタイマを内蔵している。また、制御装置４１は、三方切換弁２７の制御以外に種々の制御（たとえば、庫内の温度制御や除霜ヒータ２９の制御など）を行っている。
【００２０】
この様に構成されている実施の第１の形態の冷蔵庫は、三方切換弁２７が空冷熱交換側に切り換わっている状態で、コンプレッサ１６が稼働すると、ガス状の冷媒（ＣＯ_２　）はコンプレッサ１６の一段目で圧縮され、高温・高圧のガス状冷媒となり、ドレン蒸発パイプ２６を通り、空冷熱交換器１７の一次空冷熱交換部１７ａにおいて、空冷熱交換器用送風機１８からの空気（冷蔵庫の設置されている部屋の空気）で空冷されて温度が低下し、コンプレッサ１６に戻る。
【００２１】
そして、冷媒はコンプレッサ１６の二段目でさらに圧縮され、高温・高圧のガス状冷媒となり、空冷熱交換器１７の二次空冷熱交換部１７ｂにおいて、空冷熱交換器用送風機１８からの空気で空冷されて、超臨界域で状態変化しながら、冷媒の温度は大気温度（すなわち、冷蔵庫が設置されている部屋の温度である室温）付近まで低下する。この室温付近まで低下した冷媒は、露付防止パイプ１９に流入する。この露付防止パイプ１９は、前述のように、断熱箱体１の間口に沿って配管されているが、露付防止パイプ１９内の冷媒は、漸次温度が低下するため、冷却室６〜９の結露し易い順（すなわち、冷却室６〜９の温度の低い順）に、その周囲を巡って配管されている。この実施の形態では、冷凍室８と冷凍室９とは略同じ温度で一番低く、ついで、冷蔵室６で、一番温度の高い冷却室が野菜室７となっている。したがって、露付防止パイプ１９は、図３に図示するように、冷媒の流入側から順に、冷凍室８の右辺、冷凍室９の右辺、下辺、左辺、上辺、ついで、冷凍室８の下辺、左辺、上辺、そして、折り返して、野菜室７の下辺、左辺、冷蔵室６の左辺、上辺、右辺、下辺、ついで、折り返して、野菜室７の上辺、右辺を通り、内部熱交換器２０に向かって流出している。この様にして、露付防止パイプ１９は極力、冷凍室８，９を最初に、ついで、冷蔵室６を、その後、野菜室７の周囲を巡っており、断熱箱体１の間口の露付を効率よく防止する。
【００２２】
ついで、露付防止パイプ１９を出た冷媒は、内部熱交換器２０で冷却器２４からの戻りの冷媒で冷却され、その後、減圧装置であるキャピラリーチューブ２２および電動膨張弁２３を通って減圧され、温度が低下する。この低温の冷媒は、冷却器２４に流入し、冷却器２４の周囲の空気の温度を低下させる。冷却器２４により温度が低下した空気は、庫内ファン２８により庫内を循環し、冷却室６〜９を冷却する。冷却器２４から流れ出た冷媒は、内部熱交換器２０で高圧側の冷媒と熱交換して、温度が上昇した後に、コンプレッサ１６の流入口１６ｄに戻る。
【００２３】
制御装置４１は、庫内温度センサ３７の検出値である庫内温度（冷却室温度）が、制御装置４１に設定された冷却室設定温度になったか否かを判定し、庫内温度が冷却室設定温度以下の場合にはコンプレッサ１６を停止させ、一方、庫内温度が冷却室設定温度を越えた場合にはコンプレッサ１６を稼働させて、冷却器２４により庫内を冷却する。また、制御装置４１は、空冷熱交換器用送風機１８および庫内ファン２８を、コンプレッサ１６と略連動して稼働させており、コンプレッサ１６とともに稼働を開始させ、コンプレッサ１６が停止すると、少し遅延して停止させている。さらに、制御装置４１は、設定された時間間隔で、除霜ヒータ２９を稼働させて、冷却器２４に付着した霜を融解している。
【００２４】
冷却器２４からの除霜水であるドレン水は、ドレン容器３２に溜まる。このドレン水は、ドレン蒸発パイプ２６の高温の冷媒により加熱されて蒸発される。この際に、ドレン蒸発パイプ２６の冷媒は、逆にドレン水により冷却される。そして、この様にして、ドレン容器３２にドレン水が有り、このドレン水でドレン蒸発パイプ２６の高温の冷媒が冷却される場合には、冷媒温度は大気温度よりも低くなることがあるため、一次空冷熱交換部１７ａで逆に温められるおそれがある。そこで、三方切換弁２７をバイパス側に切り換えて、ドレン蒸発パイプ２６を通った冷媒は、一次空冷熱交換部１７ａをバイパスしてコンプレッサ１６の二段目の流入口１６ｂに流入している。なお、二段目の流入口１６ｂに流入する冷媒の温度が低い場合に、高い場合よりも、冷凍サイクルの冷却効率は向上する。
【００２５】
一方、ドレン容器３２にドレン水が無い場合には、冷凍サイクルの冷却効率を向上させるために、冷媒を一次空冷熱交換部１７ａで空冷する必要がある。そこで、三方切換弁２７を空冷熱交換側に切り換えて、ドレン蒸発パイプ２６を通った冷媒は、一次空冷熱交換部１７ａを通った後に、コンプレッサ１６の二段目の流入口１６ｂに流入している。
【００２６】
この三方切換弁２７の切り換えの作動のフローを、図６のフローチャートに基づいて説明する。
ステップ１において、制御装置４１は、水検知センサ３６からの検知信号に基づいて、ドレン容器３２に水が有るか否かを判断し、有る場合には、ステップ２に行き、制御装置４１は三方切換弁２７をバイパス側に切り換え、ステップ１に戻る。一方、ドレン水が無い場合には、ステップ３に行き、制御装置４１は三方切換弁２７を空冷熱交換側に切り換え、ステップ１に戻る。
【００２７】
前述のように、実施の形態の冷蔵庫では、コンプレッサ１６から吐出された高温の冷媒で、ドレン容器３２のドレン水を加熱して効率よく蒸発させることができる。したがって、ドレン容器３２の容積を小さくすることができる。また、ドレン蒸発パイプ２６で冷媒が水冷されており、空冷の場合よりも効率よく冷媒の温度を低下させることができる。その結果、冷凍サイクルの冷却効率を向上させることができる。特に、ドレン容器３２の水の有無で、三方切換弁２７を切り換えて、冷媒を効率よく冷却できる。
【００２８】
次に、本発明における冷蔵庫の実施の第２の形態を説明する。図７は本発明にかかる冷蔵庫の実施の第２の形態の冷媒回路の説明図である。なお、この実施の第２の形態の説明において、前記実施の第１の形態の構成要素に対応する構成要素には同一符号を付して、その詳細な説明は省略する。
【００２９】
前述の実施の第１の形態では、ドレン蒸発パイプ２６は冷凍サイクルの一段目のサイクルに設けられているが、実施の第２の形態では、ドレン蒸発パイプ４６が冷凍サイクルの二段目のサイクルに設けられている。ドレン蒸発パイプ４６は、コンプレッサ１６の二段目の吐出口１６ｃから空冷熱交換器１７の二次空冷熱交換部１７ｂへの冷媒回路中に設けられている。また、実施の第１の形態の三方切換弁２７の代わりに、バイパス切換弁としての三方切換弁４７がドレン蒸発パイプ４６の下流側すなわちドレン蒸発パイプ４６から二次空冷熱交換部１７ｂへの冷媒回路中に設けられ、この三方切換弁４７により、ドレン蒸発パイプ４６からの冷媒を二次空冷熱交換部１７ｂに流す空冷熱交換側（図７に図示した状態）と、ドレン蒸発パイプ４６からの冷媒を二次空冷熱交換部１７ｂをバイパスして露付防止パイプ１９に流すバイパス側とに切り換えることができる。
【００３０】
実施の第２の形態のドレン蒸発パイプ４６および三方切換弁４７は、実施の第１の形態のドレン蒸発パイプ２６および三方切換弁２７と、略同じ作用を行う。すなわち、ドレン容器３２に溜まったドレン水は、ドレン蒸発パイプ４６の高温の冷媒により加熱されて蒸発される。そして、ドレン容器３２にドレン水が有り、このドレン水でドレン蒸発パイプ４６の高温の冷媒が冷却される場合には、三方切換弁４７をバイパス側に切り換えて、ドレン蒸発パイプ４６を通った冷媒は、二次空冷熱交換部１７ｂをバイパスしている。
【００３１】
一方、ドレン容器３２にドレン水が無い場合には、三方切換弁４７を空冷熱交換側に切り換えて、ドレン蒸発パイプ４６を通った冷媒は、二次空冷熱交換部１７ｂを通った後に、露付防止パイプ１９に流入している。そして、制御装置４１による切り換えのフローは、三方切換弁２７が三方切換弁４７に代わる以外は、実施の第１の形態と略同じである。
【００３２】
次に、本発明における冷蔵庫の実施の第３の形態を説明する。図８は本発明にかかる冷蔵庫の実施の第３の形態の冷媒回路の説明図である。図９は一次空冷熱交換部用送風機の作動のフローチャートである。なお、この実施の第３の形態の説明において、前記実施の第１の形態の構成要素に対応する構成要素には同一符号を付して、その詳細な説明は省略する。
【００３３】
前述の実施の第１の形態では、ドレン容器３２に水がある場合には、一次空冷熱交換部１７ａで冷媒を空冷しないように、三方切換弁２７が設けられているのに対して、実施の第３の形態では、三方切換弁２７を設けずに、一次空冷熱交換部１７ａおよび二次空冷熱交換部１７ｂに対して各々送風機５１，５２を設けている。そして、送風機５１，５２は、前述の空冷熱交換器用送風機１８と同様に、コンプレッサ１６に略連動しているが、ドレン容器３２に水がある場合には、一次空冷熱交換部１７ａ用の送風機５１は停止している。
【００３４】
この一次空冷熱交換部用送風機５１の作動のフローを、図９のフローチャートに基づいて説明する。
ステップ１１において、制御装置４１は、コンプレッサ１６が稼働状態か否かを判断し、稼働状態の場合には、ステップ１２に行く。一方、コンプレッサ１６が停止状態の場合には、ステップ１１に戻る。
【００３５】
そして、ステップ１２において、制御装置４１は、水検知センサ３６からの検知信号に基づいて、ドレン容器３２に水が有るか否かを判断し、有る場合には、ステップ１３に行き、制御装置４１は送風機５１を停止させて、ステップ１１に戻る。一方、ドレン水が無い場合には、ステップ１４に行き、制御装置４１は送風機５１を稼働させて、ステップ１１に戻る。
【００３６】
この様にして、制御装置４１は、コンプレッサ１６の稼働状態で、かつ、ドレン容器３２に水が有る場合には、送風機５１を停止させ、一方、コンプレッサ１６の稼働状態で、かつ、ドレン水が無い場合には、制御装置４１は送風機５１を稼働させる。
【００３７】
前述の様にして、制御装置４１は、（１）水検知手段がドレン容器内の水を検知した際には、バイパス切換弁をバイパス側に切り換える手段、（２）水検知手段がドレン容器内の水を検知しない際には、バイパス切換弁を空冷熱交換側に切り換える手段などを具備している。
この様に、制御装置４１は、上記手段以外にも、実行される各作用に対応して各々作用を実行する手段を具備している。また、全ての手段を具備している必要は必ずしもない。
【００３８】
以上、本発明の実施の形態を詳述したが、本発明は、前記実施の形態に限定されるものではなく、特許請求の範囲に記載された本発明の要旨の範囲内で、種々の変更を行うことが可能である。本発明の変更例を下記に例示する。
（１）冷凍サイクルの冷媒は、適宜選択可能である。ただし、ＣＯ_２　が最適である。
【００３９】
（２）冷蔵庫の形式や構造などは適宜選択可能であるが、好ましくは、家庭用である。また、冷蔵庫は冷蔵室だけでなく、冷凍室も備えていることが可能である。
（３）減圧装置は、膨張弁およびキャピラリーチューブで構成されているが、他の構成でも可能である。
（４）この実施の形態では、コンプレッサは、二段圧縮式であるが、一段圧縮式でも可能である。なお、一段圧縮式の場合には、冷凍サイクルは一段目のサイクルがなくなり、二段目のサイクルのみとなる。
【００４０】
（５）この実施の形態では、内部熱交換器２０が設けられているが、キャピラリーチューブ２２と、冷凍サイクルの低圧側の冷媒配管２１とを密着させて、内部熱交換器２０の機能を果たさせることも可能である。また、内部熱交換器２０を設けないことも可能である。
（６）水検知センサ３６は、ドレン容器３２に水が有るか否かを検知することができれば、その形式は適宜選択可能である。たとえば、水位計や水温計などでも可能である。水温計の場合には、水が有ると大気温度よりも低くなるので、水温計の検出温度が低いと水が有ると分かる。
【００４１】
（７）ドレン容器３２のドレン水を、ドレン蒸発パイプ２６で加熱することができれば、その加熱構造は適宜変更可能である。この実施の形態では、ドレン蒸発パイプ２６はドレン容器３２内に配置されているが、たとえば、ドレン蒸発パイプ２６をドレン容器３２の外側に接触した状態で配管することも可能である。また、送風機によりドレン蒸発パイプ２６からドレン容器３２へ熱風を送り、ドレン容器３２のドレン水を加熱することも可能である。なお、ドレン蒸発パイプ２６をドレン水で水冷できるように、ドレン蒸発パイプ２６はドレン容器３２内に配置されるか、または、ドレン容器３２の外側に接触した状態で配管されることが好ましい。
（８）冷却器２４に付着した霜を融解させる除霜手段は、除霜ヒータ２９以外の手段でも可能である。たとえば、ホットガスで除霜することも可能である。
（９）実施の第３の形態において、ドレン蒸発パイプ２６を実施の第２の形態と同様にして、コンプレッサ１６の二段目の吐出口１６ｃと二次空冷熱交換部１７ｂとの間に設けることも可能である。そして、制御装置４１は、ドレン容器３２の水が有る場合には、一次空冷熱交換部用送風機５１ではなく二次空冷熱交換部用送風機５２を停止させる。
【００４２】
【発明の効果】
請求項１記載の発明によれば、ドレン蒸発パイプには、コンプレッサの一段目の吐出口からの高温の冷媒が流れてドレン容器のドレン水を蒸発させる。したがって、圧縮されて高温となった冷媒の熱を有効利用して、ドレン容器のドレン水を効率よく蒸発させることができる。その結果、ドレン容器の容量を小さくすることができる。
また、ドレン容器のドレン水で、一段目の冷凍サイクルの冷媒を効率よく冷却することができる。その結果、冷凍サイクルの冷却効率を向上させることができる。
【００４３】
請求項２記載の発明によれば、さらに、露付防止パイプが、冷凍サイクルの二次空冷熱交換部から減圧装置への冷媒回路中に設けられており、この露付防止パイプで断熱箱体の間口の露付を効率よく防止することができる。
【００４４】
請求項３記載の発明によれば、さらに、水検知手段がドレン容器内の水を検知した際には、バイパス切換弁をバイパス側に切り換えており、ドレン水で冷却された冷媒は一次空冷熱交換部をバイパスして流れている。したがって、ドレン水で冷却された冷媒が一次空冷熱交換部で温められることを防止することができる。
【００４５】
請求項４記載の発明によれば、さらに、水検知手段がドレン容器内の水を検知した際には、一次空冷熱交換部用送風機を停止させており、ドレン水で冷却された冷媒が、一次空冷熱交換部で空気と熱交換することが減少する。したがって、ドレン水で冷却された冷媒が一次空冷熱交換部で温められることを極力防止することができる。
【００４６】
請求項５記載の発明によれば、ドレン蒸発パイプには、コンプレッサの吐出口からの高温の冷媒が流れてドレン容器のドレン水を蒸発させる。したがって、圧縮されて高温となった冷媒の熱を有効利用して、ドレン容器のドレン水を効率よく蒸発させることができる。その結果、ドレン容器の容量を小さくすることができる。
【００４７】
請求項６記載の発明によれば、さらに、露付防止パイプが、冷凍サイクルの二次空冷熱交換部から減圧装置への冷媒回路中に設けられており、この露付防止パイプで断熱箱体の間口の露付を効率よく防止することができる。
【００４８】
請求項７記載の発明によれば、さらに、水検知手段がドレン容器内の水を検知した際には、バイパス切換弁をバイパス側に切り換えており、ドレン水で冷却された冷媒は一次空冷熱交換部をバイパスして流れている。したがって、ドレン水で冷却された冷媒が一次空冷熱交換部で温められることを防止することができる。
【００４９】
請求項８記載の発明によれば、ドレン蒸発パイプには、コンプレッサの二段目の吐出口からの高温の冷媒が流れてドレン容器のドレン水を蒸発させる。したがって、圧縮されて高温となった冷媒の熱を有効利用して、ドレン容器のドレン水を効率よく蒸発させることができる。その結果、ドレン容器の容量を小さくすることができる。さらに、水検知手段がドレン容器内の水を検知した際には、二次空冷熱交換部用送風機を停止させており、ドレン水で冷却された冷媒が、二次空冷熱交換部で空気と熱交換することが減少する。したがって、ドレン水で冷却された冷媒が二次空冷熱交換部で温められることを極力防止することができる。
【図面の簡単な説明】
【図１】図１は本発明にかかる冷蔵庫の実施の第１の形態の冷媒回路の説明図である。
【図２】図２は図１の冷蔵庫の冷媒回路の具体例の図である。
【図３】図３は図２における露付防止パイプの図である。
【図４】図４は制御装置の入出力図である。
【図５】図５は切換弁をバイパス側に切り換えた状態における実施の第１の形態の冷媒回路の説明図である。
【図６】図６は切換弁の作動のフローチャートである。
【図７】図７は本発明にかかる冷蔵庫の実施の第２の形態の冷媒回路の説明図である。
【図８】図８は本発明にかかる冷蔵庫の実施の第３の形態の冷媒回路の説明図である。
【図９】図９は一次空冷熱交換部用送風機の作動のフローチャートである。
【符号の説明】
１　断熱箱体
１６　コンプレッサ
１６ａ　一段目の吐出口
１６ｂ　二段目の流入口
１６ｃ　二段目の吐出口
１６ｄ　一段目の流入口
１７　空冷熱交換器
１７ａ　一次空冷熱交換部
１７ｂ　二次空冷熱交換部
１９　露付防止パイプ
２１　冷媒配管
２２　キャピラリーチューブ（減圧装置）
２３　電動膨張弁（減圧装置）
２４　冷却器
２６　ドレン蒸発パイプ
２７　三方切換弁（バイパス切換弁）
２９　除霜ヒータ（除霜手段）
３２　ドレン容器
３６　水検知センサ（水検知手段）
４１　制御装置（制御手段）
４７　三方切換弁（バイパス切換弁）
５１　一次空冷熱交換部用送風機
５２　二次空冷熱交換部用送風機[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a refrigerator for refrigerated storage in a refrigerator.
[0002]
[Prior art]
In a conventional refrigerator, the inside of a refrigerator is cooled by a cooler of a refrigeration cycle, and stored items are stored in the refrigerator. The refrigerant of the refrigeration cycle is generally a CFC-based refrigerant, and is liquefied in a condenser. Therefore, in this condenser, the refrigerant has a substantially constant temperature (that is, the condensation temperature).
[0003]
[Problems to be solved by the invention]
By the way, in recent years, the use of Freon-based refrigerants has been reduced, and the use of refrigerants other than Freon-based refrigerants (for example, carbon dioxide) has also been considered in refrigerators. When such a refrigerant is used, on the high pressure side of the refrigeration cycle, the refrigerant may change state in the supercritical region and not liquefy, and in order to increase the expansion of the refrigerant in the decompression device, increase the compression ratio of the compressor. I have. As described above, when the compression ratio is increased, the temperature of the compressed refrigerant greatly increases. And the heat of this refrigerant is discarded outside and is hardly used effectively.
[0004]
The present invention has been made in order to solve the above-described problems, and has an object to provide a refrigerator that is optimal for using a refrigerant that changes state in a supercritical region on the high pressure side of a refrigeration cycle and does not liquefy. I have.
[0005]
[Means for Solving the Problems]
The refrigerator according to claim 1 of the present application is a refrigerator in which an outer shell is formed of an insulated box (1), and a front opening of the refrigerator is opened and closed by an insulated door. A primary compression mechanism that compresses the refrigerant and discharges it from a first-stage discharge port (16a); and a second compression mechanism that compresses refrigerant from a second-stage inlet (16b) and discharges the refrigerant from a second-stage discharge port (16c). A compressor (16) having a secondary compression mechanism, and a primary air-cooled heat exchange unit (1) that air-cools a high-temperature, high-pressure gaseous refrigerant that has been compressed by the primary compression mechanism of the compressor from a first-stage discharge port of the compressor. 17a), the first-stage refrigeration cycle returning to the second-stage inlet of the compressor, and the gaseous refrigerant which has been compressed by the secondary compression mechanism to high temperature and high pressure from the second-stage discharge port of the compressor. Is supercritical A secondary air-cooling heat exchange unit (17b) that is air-cooled while changing the state, a decompression device (22, 23), and a cooler (24) that cools the inside of the refrigerator with a refrigerant that has been depressurized by the decompression device and has become low temperature. Then, a second-stage refrigeration cycle returning to the first-stage inlet of the compressor, a defrosting means (29) for melting frost attached to the cooler, and a drain into which drain water melted by the defrosting means flows A container (32); and a drain evaporating pipe (26) through which refrigerant in the refrigeration cycle flows to evaporate drain water in the drain container. The drain evaporating pipe is connected to the first stage of the compressor of the first stage refrigeration cycle. It is characterized by being provided in a refrigerant circuit from an outlet to a primary air-cooled heat exchange section.
[0006]
According to a second aspect of the present invention, in the refrigerator according to the first aspect, a dew-prevention pipe (19) for preventing dew of the front opening of the heat-insulating box is provided from a secondary air-cooled heat exchange part of a refrigeration cycle to a decompression device. In the refrigerant circuit.
[0007]
The refrigerator according to claim 3 is the refrigerator according to claim 1 or 2, wherein a water detecting means (36) for detecting the presence or absence of water in the drain container is provided in a refrigerant circuit from the drain evaporation pipe to a primary air-cooled heat exchange unit. And a bypass switching valve (27) for switching the flow of the refrigerant to bypass the primary air-cooling heat exchange section, and when the water detecting means detects water in the drain container, the bypass switching valve is moved to the bypass side. A switching means (41) for switching is provided.
[0008]
A refrigerator according to a fourth aspect of the present invention is the refrigerator according to the first or second aspect, wherein the primary air-cooling heat exchange section blower (51) for air-cooling the refrigerant in the primary air-cooling heat exchange section, and the refrigerant in the secondary air-cooling heat exchange section is air-cooled. A blower (52) for the secondary air-cooling heat exchange unit, a water detection unit for detecting the presence or absence of water in the drain container, and a water detection unit for the primary air-cooling heat exchange unit when the water detection unit detects water in the drain container. It is characterized by comprising control means for stopping the blower.
[0009]
The refrigerator according to claim 5, wherein the outer shell is formed of an insulated box, and a front opening of the refrigerator is opened and closed by an insulated door. An air-cooled heat exchanger (17) in which the gaseous refrigerant that has become air-cooled by a blower while changing its state in the supercritical region, a decompression device, and a cooling device that cools the inside of the refrigerator with a refrigerant that has been depressurized by the decompression device and has a low temperature. Refrigeration cycle in which units are sequentially connected in an annular manner by a refrigerant pipe (21) to return to the compressor; defrosting means for melting frost attached to the cooler; and a drain container into which drain water melted by the defrosting means flows. And a drain evaporation pipe through which the refrigerant of the refrigeration cycle flows to evaporate the drain water in the drain container, wherein the drain evaporation pipe is a refrigerant circuit downstream of the compressor. Is arranged, characterized in that the flow of high-temperature, high-pressure refrigerant from the compressor.
[0010]
According to a sixth aspect of the present invention, there is provided the refrigerator according to the fifth aspect, wherein a dew-prevention pipe for preventing dew of the front opening of the heat-insulating box is provided in a refrigerant circuit from the air-cooled heat exchanger of the refrigeration cycle to the pressure reducing device. It is characterized by having been done.
[0011]
The refrigerator according to claim 7 is the refrigerator according to claim 5 or 6, wherein a water detection unit that detects the presence or absence of water in the drain container is provided in a refrigerant circuit from the drain evaporation pipe to the air-cooled heat exchanger, A bypass switching valve (47) for switching the flow of the refrigerant to bypass the air-cooled heat exchanger; and a control means for switching the bypass switching valve to the bypass side when the water detecting means detects water in the drain container. It is characterized by having.
[0012]
The refrigerator according to claim 8 is a refrigerator in which an outer shell is formed of an insulated box, and a front opening of the refrigerator is opened and closed by an insulated door. A compressor having a primary compression mechanism that discharges from an outlet and a secondary compression mechanism that compresses refrigerant from a second-stage inflow port and discharges it from a second-stage discharge port; A first-stage refrigeration cycle that returns to a second-stage inlet of a compressor through a primary air-cooling heat exchange unit in which a high-temperature and high-pressure gaseous refrigerant compressed by a primary compression mechanism of a compressor is air-cooled; From the second-stage discharge port, a secondary air-cooled heat exchange unit, in which the gaseous refrigerant that has been compressed by the secondary compression mechanism and becomes high temperature and high pressure is air-cooled while changing its state in the supercritical region, Decompression equipment A second-stage refrigeration cycle that returns to the first-stage inlet of the compressor via a cooler that cools the inside of the refrigerator with a refrigerant that has been decompressed to a low temperature, and a defrosting unit that melts frost attached to the cooler And a drain container into which drain water melted by the defrost means flows, and a refrigerant circuit provided in a refrigerant circuit from a second-stage discharge port of a compressor of a second-stage refrigeration cycle to a secondary air-cooled heat exchange unit. A drain evaporating pipe through which the refrigerant of the cycle flows to evaporate the drain water in the drain container, a blower for the primary air-cooling heat exchange unit that air-cools the refrigerant of the primary air-cooling heat exchange unit, and a second air-cooling unit that cools the refrigerant of the secondary air-cooling heat exchange unit. Blower for secondary air cooling heat exchange unit, water detection means for detecting the presence or absence of water in drain container, and blower for secondary air cooling heat exchange unit when water detection means detects water in drain container Control means And wherein the Rukoto.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a first embodiment of a refrigerator according to the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram of a refrigerant circuit of a first embodiment of a refrigerator according to the present invention. FIG. 2 is a diagram of a specific example of a refrigerant circuit of the refrigerator of FIG. FIG. 3 is a view of the anti-dew pipe in FIG. FIG. 4 is an input / output diagram of the control device. FIG. 5 is an explanatory diagram of the refrigerant circuit of the first embodiment in a state where the switching valve is switched to the bypass side. FIG. 6 is a flowchart of the operation of the switching valve.
[0014]
The outer periphery of the household refrigerator is constituted by the heat insulating box 1 (see FIG. 3). The internal space of the heat-insulating box 1, that is, the inside of the refrigerator, is partitioned into a plurality of rooms (four in this embodiment) having different set temperatures, and a refrigerator room 6, a vegetable room 7, a freezer room 8 and a freezer room from the upper side. It is room 9. The front surfaces of the cooling chambers 6 to 9 are open, and the front openings are openably closed by heat insulating doors (not shown). Further, a rear side of the freezing room 9 is a machine room 11.
[0015]
The machine room 11 is provided with equipment for cooling the inside of the refrigerator, that is, a two-stage compression type compressor 16, an air-cooled heat exchanger 17, an air-cooled heat exchanger blower 18, and the like. The compressor 16 and the air-cooled heat exchanger 17 are connected by a refrigerant pipe 21 to form a refrigeration cycle, and CO ₂ (carbon dioxide) is used as a refrigerant of the refrigeration cycle. As shown in FIG. 1, the refrigeration cycle starts from the first-stage discharge port 16 a of the compressor 16, sequentially passes through the drain evaporation pipe 26, the primary air-cooled heat exchanger 17 a of the air-cooled heat exchanger 17, and the second compressor 16. The first-stage cycle returning to the first-stage inlet 16b and the second-stage air-cooling heat exchange part 17b of the air-cooling heat exchanger 17 and the frontage (front end) of the air-cooling heat exchanger 17 sequentially from the second-stage discharge port 16c of the compressor 16 Surface), the high pressure side pipe 20a of the internal heat exchanger 20, the capillary tube 22, the electric expansion valve 23, the cooler 24, and the low pressure side pipe of the internal heat exchanger 20. And a second-stage cycle from 20b to the first-stage inlet 16d of the compressor 16 again.
[0016]
The capillary tube 22 and the electric expansion valve 23 constitute a pressure reducing device. In the internal heat exchanger 20, the high-pressure side pipe 20a and the low-pressure side pipe 20b are in close contact with each other, and the relatively high-temperature refrigerant in the high-pressure side pipe 20a and the low-temperature refrigerant in the low-pressure side pipe 20b exchange heat. I do. In the compressor 16, the first stage compression mechanism compresses the refrigerant flowing from the first stage inlet 16d and discharges the refrigerant through the outlet 16a, and the second stage compression mechanism switches the second stage inlet The refrigerant flowing from the outlet 16b is compressed and discharged from the outlet 16c. Further, a three-way switching valve 27 is provided as a bypass switching valve in the refrigerant circuit between the drain evaporation pipe 26 and the primary air-cooling heat exchange section 17a in the first cycle, and the three-way switching valve 27 allows the drain evaporation pipe 26 -Cooling heat exchange side (the state shown in FIG. 1) in which the refrigerant from the compressor 16 flows into the primary air-cooling heat exchange unit 17a, and the refrigerant from the drain evaporation pipe 26 bypasses the primary air-cooling heat exchange unit 17a to the second stage of the compressor 16. Can be switched to the bypass side (the state shown in FIG. 5) which returns to the inflow port 16b.
[0017]
Then, the cooler 24 has a low temperature, and lowers the temperature of the surrounding air. The cool air around the cooler 24 is blown and circulated by the fan 28 in the refrigerator to cool the refrigerator. Thus, the inside of the refrigerator can be cooled by the cooler 24. Since frost adheres to the cooler 24, the frost is melted at appropriate time intervals by a defrost heater 29 as defrosting means to perform defrost. Drain water as defrost water from the cooler 24 is received by the dew tray 31, falls from the dew tray 31, and is stored in the drain container 32. The above-described drain evaporation pipe 26 is provided in the drain container 32, and the drain water in the drain container 32 is heated by the high-temperature refrigerant in the drain evaporation pipe 26 to evaporate.
[0018]
Further, the area from the discharge port 16c of the compressor 16 to the electric expansion valve 23 is on the high pressure side of the refrigeration cycle, and the area from the electric expansion valve 23 to the inlet 16d of the compressor 16 is on the low pressure side of the refrigeration cycle. As a detecting means, a water detecting sensor 36 as a water detecting means for detecting the presence or absence of water in the drain container 32, and a cooling chamber for detecting the temperature in the refrigerator (in this embodiment, the temperature of the freezing room 8, which is a cooling room). An internal temperature sensor 37 is provided as temperature detecting means.
[0019]
Further, as shown in FIG. 4, the refrigerator is provided with a control device 41, and the control device 41 is configured by a microcomputer or the like. Various electrical components are connected to the control device 41. In particular, as the electrical components for controlling the three-way switching valve 27 and the like, a water detection sensor 36 and an in-compartment temperature sensor 37 are provided on the input side. On the other hand, an air-cooling heat exchanger blower 18, an electric expansion valve 23, an internal fan 28, a compressor 16, a three-way switching valve 27, a defrost heater 29, and the like are connected to the output side. Note that various setting values are stored in a storage unit (ROM, RAM, or the like) of the control device 41, and a timer (not shown) is built in. Further, the control device 41 performs various controls other than the control of the three-way switching valve 27 (for example, the temperature control in the refrigerator, the control of the defrost heater 29, and the like).
[0020]
When the compressor 16 is operated in a state in which the three-way switching valve 27 is switched to the air-cooled heat exchange side, the refrigerator according to the first embodiment having the above-described configuration converts the gaseous refrigerant (CO ₂ ) into the compressor. 16 is compressed in the first stage to become a high-temperature and high-pressure gaseous refrigerant, passes through a drain evaporation pipe 26, and in a primary air-cooling heat exchange section 17a of an air-cooling heat exchanger 17, air from an air-cooling heat exchanger blower 18 (of a refrigerator). The air is cooled by the air in the installed room), the temperature is reduced, and the flow returns to the compressor 16.
[0021]
Then, the refrigerant is further compressed in the second stage of the compressor 16 to become a high-temperature and high-pressure gaseous refrigerant, and is air-cooled by air from the air-cooling heat exchanger blower 18 in the secondary air-cooling heat exchanger 17 b of the air-cooling heat exchanger 17. Then, while changing the state in the supercritical region, the temperature of the refrigerant drops to near the atmospheric temperature (that is, room temperature which is the temperature of the room where the refrigerator is installed). The refrigerant that has dropped to around room temperature flows into the dew-prevention pipe 19. As described above, the dew-prevention pipe 19 is provided along the frontage of the heat-insulating box 1. However, since the temperature of the refrigerant in the dew-prevention pipe 19 gradually decreases, the cooling chambers 6 to 9 are formed. (That is, the order of decreasing the temperature of the cooling chambers 6 to 9). In this embodiment, the freezing compartment 8 and the freezing compartment 9 have the lowest temperature at substantially the same temperature, and the cooling compartment 6 having the highest temperature in the refrigerator compartment 6 is the vegetable compartment 7. Therefore, as shown in FIG. 3, the dew-prevention pipe 19 includes, in order from the refrigerant inflow side, the right side of the freezing room 8, the right side, the lower side, the left side, the upper side of the freezing room 9, the lower side of the freezing room 8, The left side, the upper side, and then turned back, the lower side, the left side of the vegetable compartment 7, the left side, the upper side, the right side, the lower side of the refrigerator compartment 6, and then turned back, passed through the upper side, the right side of the vegetable room 7, to the internal heat exchanger 20. It is flowing out. In this way, the dew-prevention pipe 19 travels as much as possible in the freezing compartments 8 and 9 first, then in the refrigerator compartment 6 and then in the periphery of the vegetable compartment 7, and is exposed to the dew at the frontage of the heat insulating box 1. Is efficiently prevented.
[0022]
Next, the refrigerant that has exited the dew-prevention pipe 19 is cooled by the refrigerant returned from the cooler 24 in the internal heat exchanger 20, and then depressurized through the capillary tube 22 and the electric expansion valve 23 which are pressure reducing devices. , The temperature drops. This low-temperature refrigerant flows into the cooler 24 and lowers the temperature of the air around the cooler 24. The air whose temperature has been lowered by the cooler 24 is circulated in the refrigerator by the fan 28 in the refrigerator, and cools the cooling chambers 6 to 9. The refrigerant flowing out of the cooler 24 exchanges heat with the refrigerant on the high pressure side in the internal heat exchanger 20 and returns to the inlet 16 d of the compressor 16 after the temperature rises.
[0023]
The control device 41 determines whether or not the inside temperature (cooling room temperature) detected by the inside temperature sensor 37 has reached the cooling room set temperature set in the control device 41, and the inside temperature is cooled. When the temperature is equal to or lower than the chamber set temperature, the compressor 16 is stopped. On the other hand, when the internal temperature exceeds the cooling chamber set temperature, the compressor 16 is operated and the cooler 24 cools the internal space. Further, the control device 41 operates the blower 18 for the air-cooling heat exchanger and the fan 28 in the refrigerator substantially in conjunction with the compressor 16. The controller 41 starts the operation together with the compressor 16. Has been stopped. Further, the control device 41 operates the defrost heater 29 at set time intervals to melt frost attached to the cooler 24.
[0024]
Drain water as defrost water from the cooler 24 accumulates in the drain container 32. The drain water is heated and evaporated by the high-temperature refrigerant in the drain evaporation pipe 26. At this time, the refrigerant in the drain evaporation pipe 26 is cooled by the drain water. When the drain water is present in the drain container 32 and the high-temperature refrigerant in the drain evaporation pipe 26 is cooled by the drain water, the refrigerant temperature may be lower than the atmospheric temperature. There is a possibility that the primary air-cooled heat exchange section 17a may be heated on the contrary. Therefore, the three-way switching valve 27 is switched to the bypass side, and the refrigerant that has passed through the drain evaporation pipe 26 flows into the second-stage inlet 16b of the compressor 16 bypassing the primary air-cooling heat exchange unit 17a. In addition, when the temperature of the refrigerant flowing into the second-stage inlet 16b is low, the cooling efficiency of the refrigeration cycle is higher than when the temperature is high.
[0025]
On the other hand, when there is no drain water in the drain container 32, it is necessary to air-cool the refrigerant in the primary air-cooling heat exchange unit 17a in order to improve the cooling efficiency of the refrigeration cycle. Therefore, the three-way switching valve 27 is switched to the air-cooling heat exchange side, and the refrigerant that has passed through the drain evaporation pipe 26 flows into the second-stage inlet 16b of the compressor 16 after passing through the primary air-cooling heat exchange section 17a. I have.
[0026]
The flow of the switching operation of the three-way switching valve 27 will be described with reference to the flowchart of FIG.
In step 1, the control device 41 determines whether or not there is water in the drain container 32 based on the detection signal from the water detection sensor 36, and if there is, goes to step 2 and the control device 41 The switching valve 27 is switched to the bypass side, and the process returns to step 1. On the other hand, if there is no drain water, the procedure goes to step 3, where the control device 41 switches the three-way switching valve 27 to the air-cooled heat exchange side, and returns to step 1.
[0027]
As described above, in the refrigerator of the embodiment, the high-temperature refrigerant discharged from the compressor 16 can heat the drain water in the drain container 32 to efficiently evaporate. Therefore, the capacity of the drain container 32 can be reduced. In addition, since the refrigerant is water-cooled in the drain evaporation pipe 26, the temperature of the refrigerant can be reduced more efficiently than in the case of air cooling. As a result, the cooling efficiency of the refrigeration cycle can be improved. In particular, by switching the three-way switching valve 27 depending on the presence or absence of water in the drain container 32, the refrigerant can be efficiently cooled.
[0028]
Next, a second embodiment of the refrigerator according to the present invention will be described. FIG. 7 is an explanatory diagram of a refrigerant circuit according to a second embodiment of the refrigerator according to the present invention. In the description of the second embodiment, components corresponding to the components of the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.
[0029]
In the first embodiment described above, the drain evaporation pipe 26 is provided in the first cycle of the refrigeration cycle. In the second embodiment, the drain evaporation pipe 46 is provided in the second cycle of the refrigeration cycle. It is provided in. The drain evaporation pipe 46 is provided in a refrigerant circuit from a second-stage discharge port 16 c of the compressor 16 to a secondary air-cooled heat exchange section 17 b of the air-cooled heat exchanger 17. Also, instead of the three-way switching valve 27 of the first embodiment, a three-way switching valve 47 as a bypass switching valve is provided on the downstream side of the drain evaporation pipe 46, that is, the refrigerant from the drain evaporation pipe 46 to the secondary air-cooled heat exchange unit 17b. The three-way switching valve 47 is provided in the circuit, and the three-way switching valve 47 allows the refrigerant from the drain evaporating pipe 46 to flow to the secondary air-cooling heat exchanging section 17b on the air cooling heat exchange side (the state shown in FIG. The refrigerant can be switched to the bypass side in which the refrigerant bypasses the secondary air cooling heat exchange section 17b and flows to the dew-prevention pipe 19.
[0030]
The drain evaporation pipe 46 and the three-way switching valve 47 according to the second embodiment have substantially the same functions as the drain evaporation pipe 26 and the three-way switching valve 27 according to the first embodiment. That is, the drain water accumulated in the drain container 32 is heated by the high-temperature refrigerant in the drain evaporation pipe 46 and evaporated. When the drain water is present in the drain container 32 and the high-temperature refrigerant in the drain evaporation pipe 46 is cooled by the drain water, the three-way switching valve 47 is switched to the bypass side, and the refrigerant passing through the drain evaporation pipe 46 is passed through. Is bypassing the secondary air-cooled heat exchange section 17b.
[0031]
On the other hand, when there is no drain water in the drain container 32, the three-way switching valve 47 is switched to the air-cooling heat exchange side, and the refrigerant that has passed through the drain evaporation pipe 46 passes through the secondary air-cooling heat exchange unit 17b, and then is discharged. It flows into the attachment prevention pipe 19. The flow of switching by the control device 41 is substantially the same as that of the first embodiment except that the three-way switching valve 27 is replaced with the three-way switching valve 47.
[0032]
Next, a third embodiment of the refrigerator according to the present invention will be described. FIG. 8 is an explanatory diagram of a refrigerant circuit according to a third embodiment of the refrigerator according to the present invention. FIG. 9 is a flowchart of the operation of the blower for the primary air-cooling heat exchange unit. In the description of the third embodiment, the same reference numerals are given to components corresponding to the components of the first embodiment, and a detailed description thereof will be omitted.
[0033]
In the first embodiment described above, the three-way switching valve 27 is provided so that the refrigerant is not air-cooled in the primary air-cooling heat exchange unit 17a when there is water in the drain container 32. In the third embodiment, the blowers 51 and 52 are provided for the primary air-cooling heat exchange unit 17a and the secondary air-cooling heat exchange unit 17b, respectively, without providing the three-way switching valve 27. The blowers 51 and 52 are substantially interlocked with the compressor 16 similarly to the blower 18 for the air-cooling heat exchanger described above, but when there is water in the drain container 32, the blowers for the primary air-cooling heat exchanger 17a are provided. 51 is stopped.
[0034]
The operation flow of the primary air-cooling heat exchange section blower 51 will be described with reference to the flowchart of FIG.
In step 11, the control device 41 determines whether or not the compressor 16 is in operation. If the compressor 16 is in operation, the process proceeds to step 12. On the other hand, when the compressor 16 is in the stopped state, the process returns to step S11.
[0035]
Then, in step 12, the control device 41 determines whether or not there is water in the drain container 32 based on the detection signal from the water detection sensor 36, and if there is, the process proceeds to step 13 and the control device 41 Stops the blower 51 and returns to step 11. On the other hand, if there is no drain water, the procedure goes to step 14, where the control device 41 operates the blower 51 and returns to step 11.
[0036]
In this way, the control device 41 stops the blower 51 when the compressor 16 is in operation and the drain container 32 has water, and on the other hand, when the compressor 16 is in operation and the drain water is If not, the control device 41 operates the blower 51.
[0037]
As described above, the control device 41 is configured to (1) switch the bypass switching valve to the bypass side when the water detecting means detects water in the drain container, and (2) determine whether the water detecting means is in the drain container. When the water is not detected, means for switching the bypass switching valve to the air-cooled heat exchange side is provided.
As described above, the control device 41 includes, in addition to the above-described means, means for executing each action corresponding to each action to be executed. Also, not all means need be provided.
[0038]
As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the above embodiments, and various modifications may be made within the scope of the present invention described in the appended claims. It is possible to do. Modification examples of the present invention are exemplified below.
(1) The refrigerant of the refrigeration cycle can be appropriately selected. However, CO ₂ is optimal.
[0039]
(2) The type and structure of the refrigerator can be appropriately selected, but it is preferably for home use. Further, the refrigerator can include not only a refrigerator but also a freezer.
(3) The decompression device is composed of an expansion valve and a capillary tube, but other configurations are also possible.
(4) In this embodiment, the compressor is of a two-stage compression type, but may be of a one-stage compression type. In the case of the single-stage compression type, the refrigeration cycle does not include the first-stage cycle but only the second-stage cycle.
[0040]
(5) Although the internal heat exchanger 20 is provided in this embodiment, the capillary tube 22 and the refrigerant pipe 21 on the low pressure side of the refrigeration cycle are brought into close contact with each other to perform the function of the internal heat exchanger 20. It is also possible to make it work. Moreover, it is also possible not to provide the internal heat exchanger 20.
(6) The type of the water detection sensor 36 can be appropriately selected as long as it can detect whether or not the drain container 32 has water. For example, a water level gauge or a water temperature gauge can be used. In the case of a water thermometer, if water is present, the temperature becomes lower than the atmospheric temperature. Therefore, it can be understood that water is present when the temperature detected by the water thermometer is low.
[0041]
(7) As long as the drain water in the drain container 32 can be heated by the drain evaporation pipe 26, the heating structure can be appropriately changed. In this embodiment, the drain evaporation pipe 26 is disposed inside the drain container 32. However, for example, the drain evaporation pipe 26 may be connected to the outside of the drain container 32 in a state where the drain evaporation pipe 26 is in contact therewith. It is also possible to send hot air from the drain evaporation pipe 26 to the drain container 32 by a blower to heat the drain water in the drain container 32. It is preferable that the drain evaporation pipe 26 be disposed in the drain container 32 or be piped in contact with the outside of the drain container 32 so that the drain evaporation pipe 26 can be water-cooled with drain water.
(8) The defrosting means for melting the frost attached to the cooler 24 can be any means other than the defrosting heater 29. For example, defrosting with hot gas is also possible.
(9) In the third embodiment, the drain evaporation pipe 26 is provided between the discharge port 16c of the second stage of the compressor 16 and the secondary air-cooled heat exchange section 17b in the same manner as in the second embodiment. It is also possible. Then, when there is water in the drain container 32, the control device 41 stops the blower 52 for the secondary air-cooling heat exchange unit instead of the blower 51 for the primary air-cooling heat exchange unit.
[0042]
【The invention's effect】
According to the first aspect of the present invention, the high-temperature refrigerant flows from the discharge outlet of the first stage of the compressor to the drain evaporation pipe to evaporate the drain water in the drain container. Therefore, the drain water in the drain container can be efficiently evaporated by effectively utilizing the heat of the compressed and high-temperature refrigerant. As a result, the capacity of the drain container can be reduced.
Further, the refrigerant in the first-stage refrigeration cycle can be efficiently cooled by the drain water in the drain container. As a result, the cooling efficiency of the refrigeration cycle can be improved.
[0043]
According to the second aspect of the present invention, the dew-prevention pipe is further provided in the refrigerant circuit from the secondary air-cooling heat exchange unit of the refrigeration cycle to the pressure reducing device. Exposure of the frontage can be efficiently prevented.
[0044]
According to the third aspect of the invention, when the water detecting means detects the water in the drain container, the bypass switching valve is switched to the bypass side, and the refrigerant cooled by the drain water is cooled by the primary air cooling heat. It flows bypassing the exchange unit. Therefore, it is possible to prevent the refrigerant cooled by the drain water from being heated in the primary air-cooling heat exchange unit.
[0045]
According to the invention as set forth in claim 4, when the water detecting means detects water in the drain container, the blower for the primary air-cooled heat exchange unit is stopped, and the refrigerant cooled by the drain water is Heat exchange with air in the primary air-cooled heat exchange section is reduced. Therefore, it is possible to prevent the refrigerant cooled by the drain water from being heated in the primary air-cooling heat exchange unit as much as possible.
[0046]
According to the fifth aspect of the present invention, the high-temperature refrigerant flows from the discharge port of the compressor to the drain evaporation pipe to evaporate the drain water in the drain container. Therefore, the drain water in the drain container can be efficiently evaporated by effectively utilizing the heat of the compressed and high-temperature refrigerant. As a result, the capacity of the drain container can be reduced.
[0047]
According to the invention as set forth in claim 6, the dew-prevention pipe is further provided in the refrigerant circuit from the secondary air-cooling heat exchange unit of the refrigeration cycle to the pressure reducing device. Exposure of the frontage can be efficiently prevented.
[0048]
According to the seventh aspect of the present invention, when the water detecting means detects the water in the drain container, the bypass switching valve is switched to the bypass side, and the refrigerant cooled by the drain water is cooled by the primary air cooling heat. It flows bypassing the exchange unit. Therefore, it is possible to prevent the refrigerant cooled by the drain water from being heated in the primary air-cooling heat exchange unit.
[0049]
According to the eighth aspect of the present invention, a high-temperature refrigerant flows from the second-stage discharge port of the compressor into the drain evaporation pipe to evaporate the drain water in the drain container. Therefore, the drain water in the drain container can be efficiently evaporated by effectively utilizing the heat of the compressed and high-temperature refrigerant. As a result, the capacity of the drain container can be reduced. Further, when the water detecting means detects the water in the drain container, the secondary air cooling heat exchange unit blower is stopped, and the refrigerant cooled by the drain water is mixed with air in the secondary air cooling heat exchange unit. Heat exchange is reduced. Therefore, it is possible to prevent the refrigerant cooled by the drain water from being heated in the secondary air-cooling heat exchange unit as much as possible.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a refrigerant circuit of a first embodiment of a refrigerator according to the present invention.
FIG. 2 is a diagram of a specific example of a refrigerant circuit of the refrigerator of FIG.
FIG. 3 is a view of a dew-prevention pipe in FIG. 2;
FIG. 4 is an input / output diagram of a control device.
FIG. 5 is an explanatory diagram of the refrigerant circuit of the first embodiment in a state where the switching valve is switched to the bypass side.
FIG. 6 is a flowchart of the operation of the switching valve.
FIG. 7 is an explanatory diagram of a refrigerant circuit according to a second embodiment of the refrigerator according to the present invention.
FIG. 8 is an explanatory diagram of a refrigerant circuit according to a third embodiment of the refrigerator according to the present invention.
FIG. 9 is a flowchart of the operation of a blower for a primary air-cooling heat exchange unit.
[Explanation of symbols]
1 Insulated box 16 Compressor 16a First stage outlet 16b Second stage inlet 16c Second stage outlet 16d First stage inlet 17 Air-cooled heat exchanger 17a Primary air-cooled heat exchanger 17b Secondary air-cooled heat exchanger 19 Dew prevention pipe 21 Refrigerant pipe 22 Capillary tube (pressure reducing device)
23 Electric expansion valve (pressure reducing device)
24 cooler 26 drain evaporation pipe 27 three-way switching valve (bypass switching valve)
29 Defrost heater (defrost means)
32 drain container 36 water detection sensor (water detection means)
41 control device (control means)
47 Three-way switching valve (bypass switching valve)
51 Blower for primary air-cooled heat exchange section 52 Blower for secondary air-cooled heat exchange section

Claims

In a refrigerator in which the outer shell is formed of an insulated box and the front opening of which is opened and closed by an insulated door,
A primary compression mechanism that compresses refrigerant from the first-stage inlet and discharges it from the first-stage outlet, and a secondary compression that compresses refrigerant from the second-stage inlet and discharges it from the second-stage outlet. A compressor having a mechanism;
From the first-stage discharge port of the compressor, the gaseous refrigerant that has been compressed by the primary compression mechanism of the compressor and becomes high temperature and high pressure passes through a primary air-cooled heat exchange section where it is air-cooled, and returns to the second-stage inlet of the compressor. The first refrigeration cycle,
From the discharge port of the second stage of the compressor, a secondary air-cooled heat exchange section that is air-cooled while the gaseous refrigerant that has been compressed by the secondary compression mechanism and becomes high temperature and high pressure changes state in the supercritical region, A second-stage refrigeration cycle that returns to the first-stage inlet of the compressor through a cooler that cools the inside of the refrigerator with a refrigerant that has been decompressed by the decompression device and has a low temperature;
Defrosting means for melting the frost attached to the cooler,
A drain container into which drain water melted by the defrost means flows,
A drain evaporation pipe that allows the refrigerant of the refrigeration cycle to flow and evaporate the drain water of the drain container,
The refrigerator, wherein the drain evaporation pipe is provided in a refrigerant circuit from a first-stage discharge port of the compressor of the first-stage refrigeration cycle to a primary air-cooled heat exchange unit.

The dew-prevention pipe for preventing dew at the frontage of the heat-insulating box is provided in a refrigerant circuit from a secondary air-cooled heat exchange part of a refrigeration cycle to a decompression device. refrigerator.

Water detection means for detecting the presence or absence of water in the drain container,
A bypass switching valve that is provided in the refrigerant circuit from the drain evaporation pipe to the primary air-cooled heat exchange unit and switches the flow of the refrigerant to bypass the primary air-cooled heat exchange unit;
3. The refrigerator according to claim 1, further comprising control means for switching a bypass switching valve to a bypass side when the water detecting means detects water in the drain container.

A blower for the primary air-cooling heat exchange unit that air-cools the refrigerant in the primary air-cooling heat exchange unit,
A blower for a secondary air-cooled heat exchange unit that air-cools the refrigerant in the secondary air-cooled heat exchange unit,
Water detection means for detecting the presence or absence of water in the drain container,
The refrigerator according to claim 1 or 2, further comprising control means for stopping the blower for the primary air-cooling heat exchange unit when the water detection means detects water in the drain container.

In a refrigerator in which the outer shell is formed of an insulated box and the front opening of which is opened and closed by an insulated door,
A compressor that compresses the refrigerant, an air-cooled heat exchanger in which the gaseous refrigerant that has been compressed by the compressor and becomes high temperature and high pressure is air-cooled by a blower while changing state in a supercritical region, a decompression device, and decompressed by the decompression device. A refrigeration cycle in which a cooler that cools the inside of the refrigerator with a low-temperature refrigerant is sequentially connected in an annular manner with a refrigerant pipe and returns to the compressor,
Defrosting means for melting the frost attached to the cooler,
A drain container into which drain water melted by the defrost means flows,
A drain evaporation pipe that allows the refrigerant of the refrigeration cycle to flow to evaporate the drain water of the drain container,
The refrigerator, wherein the drain evaporation pipe is disposed in a refrigerant circuit downstream of the compressor, and a high-temperature and high-pressure refrigerant flows from the compressor.

6. The refrigerator according to claim 5, wherein a dew-prevention pipe for preventing dew from being exposed at a frontage of the heat-insulating box is provided in a refrigerant circuit from the air-cooled heat exchanger of the refrigeration cycle to the pressure reducing device.

Water detection means for detecting the presence or absence of water in the drain container,
A bypass switching valve that is provided in the refrigerant circuit from the drain evaporation pipe to the air-cooled heat exchanger and switches the flow of the refrigerant to bypass the air-cooled heat exchanger;
7. The refrigerator according to claim 5, further comprising control means for switching a bypass switching valve to a bypass side when the water detecting means detects water in the drain container.

In a refrigerator in which the outer shell is formed of an insulated box and the front opening of which is opened and closed by an insulated door,
A primary compression mechanism that compresses refrigerant from the first-stage inlet and discharges it from the first-stage outlet, and a secondary compression that compresses refrigerant from the second-stage inlet and discharges it from the second-stage outlet. A compressor having a mechanism;
From the first-stage discharge port of the compressor, the gaseous refrigerant that has been compressed by the primary compression mechanism of the compressor and becomes high temperature and high pressure passes through a primary air-cooled heat exchange section where it is air-cooled, and returns to the second-stage inlet of the compressor. The first refrigeration cycle,
From the discharge port of the second stage of the compressor, a secondary air-cooled heat exchange section that is air-cooled while the gaseous refrigerant that has been compressed by the secondary compression mechanism and becomes high temperature and high pressure changes state in the supercritical region, A second-stage refrigeration cycle that returns to the first-stage inlet of the compressor through a cooler that cools the inside of the refrigerator with a refrigerant that has been decompressed by the decompression device and has a low temperature;
Defrosting means for melting the frost attached to the cooler,
A drain container into which drain water melted by the defrost means flows,
A drain evaporating pipe that is provided in a refrigerant circuit from a second-stage discharge port of a compressor of a second-stage refrigeration cycle to a secondary air-cooled heat exchange section, through which refrigerant of the refrigeration cycle flows to evaporate drain water of a drain container, and ,
A blower for a primary air-cooling heat exchange unit that air-cools a refrigerant in a primary air-cooling heat exchange unit,
A blower for a secondary air-cooled heat exchange unit that air-cools the refrigerant of the secondary air-cooled heat exchange unit,
Water detection means for detecting the presence or absence of water in the drain container,
A refrigerator comprising: a control unit that stops a blower for a secondary air-cooling heat exchange unit when the water detection unit detects water in a drain container.