JP2004197966A

JP2004197966A - Refrigerator

Info

Publication number: JP2004197966A
Application number: JP2002363471A
Authority: JP
Inventors: Tetsuya Saito; 哲哉斎藤; Munetaka Yamada; 宗登山田; Shusaku Watakabe; 周作渡壁
Original assignee: Matsushita Refrigeration Co
Current assignee: Panasonic Holdings Corp
Priority date: 2002-12-16
Filing date: 2002-12-16
Publication date: 2004-07-15

Abstract

<P>PROBLEM TO BE SOLVED: To reduce penetrating heat quantity from a heat radiation pipe in operation of a compressor with relation to energy saving of a refrigerator. <P>SOLUTION: In this refrigerator, a condenser of a freezing cycle 29 is composed of only a heat radiation pipe 22 disposed in a refrigerator case, and operation of the compressor 21 is controlled by a refrigerator temperature detecting means TH1 provided in the refrigerator 26. The compressor 21 is composed as an ability-changeable type. At the time of a low load without no opening and close of doors, ability of the compressor 21 is lowered, so that temperature of the heat radiation pipe 22 is reduced. Thermal effect from the heat radiation pipe 22 into the refrigerator can thus be reduced to greatly save energy. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、冷蔵庫の省エネルギーに関するものである。
【０００２】
【従来の技術】
近年、冷却システムの凝縮器としての放熱パイプを冷蔵庫箱体内に配設した冷蔵庫が普及している（例えば、特許文献１参照）。
【０００３】
図１１に従来の冷却サイクル並びに冷蔵庫の概略図を示す。
【０００４】
冷蔵庫１の本体２は、前方に開口する鋼板製の外箱３と、この外箱３内に間隔を持たせて組み込まれた前方に開口する合成樹脂製の内箱４と、これら外箱３と内箱４間に充填発泡された発泡ポリウレタン断熱材５とから構成されている。内箱４は上下に仕切る水平の仕切部（６ａ、６ｂ、６ｃ）によって上下４段に区画され貯蔵室が形成されている。最上段に冷蔵室１１、２段目に野菜室１２、３段目左側に製氷室１３Ａと、同じく右側に切替室１３Ｂ、４段目に冷凍室１４が配置され、製氷室１３Ａと切替室１３Ｂとの間には、縦仕切壁１５が設けられている。
【０００５】
これら各貯蔵室の開口側には、各貯蔵室に対応して開閉自在に密閉される図示しない扉が設けられ、各扉には庫内と外気とをシールするため、図示しない扉ガスケットが設けられている。
【０００６】
この扉ガスケットと本体側の開口周辺の前面部１６で庫内温度と外気温度との差異によって結露が生じる恐れがある。この結露を防止するため放熱パイプ８が配設されている。なお、冷蔵室１１および野菜室１２が冷蔵温度帯、製氷室１３Ａおよび冷凍室１４が冷凍温度帯に保持されている。切替室１３Ｂは、庫内温度が選択可能である。
【０００７】
また、放熱パイプ８は、機械室に配設される図示しない圧縮機から吐出された高い温度の冷媒が流れる配管を庫内温度と外気温度との差が大きい冷凍室１４や製氷室１３Ａの開口に配設し、逆に放熱が進んで温度が低下した配管を温度差の小さい冷蔵室１１の開口に配設した構成としている。
【０００８】
これにより、各温度帯室周辺で発生する結露を防止するのに見合った熱量を適正に分配することが可能となる。
【０００９】
【特許文献１】
特開２００２−６２０２３号公報
【００１０】
【発明が解決しようとする課題】
しかしながら、上記従来の構成は、結露は抑えられるものの圧縮機から吐出された高い温度の冷媒が流れる放熱パイプ８を、放熱パイプと温度差が大きい冷凍室１４周辺部に配設する構成としているために、圧縮機運転時の放熱パイプ８から冷凍室１４への侵入熱量が極端に大きくなり、エネルギー消費量が大きくなるという課題があった。
【００１１】
また、従来より、２００Ｌ以下の冷蔵庫に多く採用されている冷蔵庫は、コスト低減、容積効率向上による省スペース化を図るために、冷蔵庫箱体内のみに放熱パイプを配設している。このような冷蔵庫では、機械室内に凝縮器を配設して庫外に放熱した後、冷蔵庫箱体内の放熱パイプで放熱を行う形式の冷蔵庫と比較して、圧縮機運転時の放熱パイプから庫内への侵入熱量が大きいことが課題であった。
【００１２】
また、従来より、２００Ｌ以下のいわゆる小型冷蔵庫と呼ばれるものにおいては、コスト低減を図るため、冷凍室に設けた冷却器と冷却ファンからの冷気を冷蔵室内に配分し、冷蔵室の温度を検知して圧縮機の運転を制御し、冷蔵室内に自動ダンパーを設けないものがある。このような冷蔵庫では、冷蔵室の温度を優先して制御するため、たとえば周囲温度が低くなった場合、周囲からの吸熱による冷蔵室内の温度上昇が少なくなり、圧縮機の運転率が低下することで、冷凍室の温度が所定の温度を確保できなくなるという課題があった。そして、その課題を解決するために冷蔵室内にヒータを設け、圧縮機停止時に加熱することが行なわれ、増電要素となっていた。
【００１３】
本発明は、従来の課題を解決するもので、２００Ｌ以下のいわゆる小型冷蔵庫の省エネルギーを図ることを目的とする。
【００１４】
【課題を解決するための手段】
本発明の請求項１に記載の発明は、冷蔵室、冷凍室を有し、冷凍サイクルの凝縮器が冷蔵庫箱体内に配設した放熱パイプのみで構成され、前記冷蔵室内に設置した冷蔵室温度検知手段により圧縮機の運転を制御する冷蔵庫において、圧縮機を能力可変型としたものであり、庫内の負荷変動に合わせて圧縮機の能力を可変できるので例えば扉開閉のない安定時には、圧縮機の能力を小さくすることにより高圧側圧力が下がり、凝縮器としての放熱パイプの温度を下げることができ、庫内への侵入熱量の低減が可能となり省エネルギー化が図れる。また、圧縮機を低い能力で運転することで圧縮機の運転時間を延ばすことができ冷凍室に必要な冷却量を確保することが可能となる。
【００１５】
また、圧縮機の運転時間が延びるので放熱パイプによる冷蔵庫外表面の結露防止効果が大きくなる。
【００１６】
請求項２に記載の発明は、請求項１に記載の発明において、冷蔵室側ウレタン内もしくは冷蔵室庫内に冷蔵室を加熱するヒータを設け、圧縮機停止時に通電するものであり、低外気温時、冷凍室温度を確保できるとともに、圧縮機を低い能力で運転することで圧縮機停止時間を減らし、ヒータの通電率を小さくすることができ、消費電力量の低減が可能となる。
【００１７】
請求項３に記載の発明は、請求項２に記載の発明において、外気温度検知手段により検知した温度によりヒータの通電率を制御するものであり、周囲温度に適したヒータの通電が可能となり、従来、特に圧縮機の運転時間が短くなる低外気温時の冷凍室の冷却量を確保するためにアルミ箔ヒータを圧縮機の運転時間が長い高外気温時にも圧縮機停止時に１００％一定通電しており、無駄な熱量を冷蔵室庫内に与えていたために消費電力量の増大の要因となっていたが、外気温が高くなるとアルミ箔ヒータを必要最小限の通電率で通電することにより無駄がなくなり大幅な消費電力量の低減が可能となる。
【００１８】
請求項４に記載の発明は、請求項１から請求項３のいずれか一項に記載の発明において、外気温温度検知手段により検知した温度により、ファンの回転数を可変するものであり、低外気温時にファンの回転数つまり送風量を下げると、冷凍室の風量比率が大きくなり冷蔵室の風量比率が小さくなるので、冷凍室と冷蔵室の冷却量比率が冷凍室側に大きくなり、冷凍室の冷却量の確保が容易となる。また、冷蔵室の冷却量比率が低下するので圧縮機の停止時間が短くなり、アルミ箔ヒータの通電時間を短くすることができ消費電力量の削減が可能となる。
【００１９】
請求項５に記載の発明は、請求項１から請求項４のいずれか一項に記載の発明において、能力可変型圧縮機の回転数を２段階制御としたものであり、多段変速型の場合は庫内負荷と連動して速やかに圧縮機の回転数を上げることができるので、負荷変動に対してフレキシブルに対応できるというメリットがある反面、圧縮比が大きく効率が悪い状態での運転時間が長くなるので消費電力量が大きくなるという課題があったが、圧縮機の回転数変化幅を２段階とし庫内負荷が極端に増大した場合のみ、高速側の回転数で運転し、基本は低速側の回転数で運転することにより圧縮比が小さく効率が良い状態での運転時間を長くできるので消費電力量を削減することが可能となる。
【００２０】
また、圧縮機の能力を速やかに上げていく多段変速型と比較して２段階にすることにより圧縮機の運転時間を延ばすことができるので、冷凍室に必要な冷却量を確保しやすくなるので、従来と比較してアルミ箔ヒータの通電率を小さくすることができ、消費電力量の低減が可能となる。
【００２１】
請求項６に記載の発明は、請求項５に記載の発明において、能力可変型圧縮機の回転数の低速側と高速側の回転数比を１．５倍以下としたものであり、高速時の圧縮機の冷却能力を最小限に抑えることにより、圧縮機の運転時間を最大限にまで延ばすことができ、冷凍室に必要な冷却量を確保しやすくなるので、従来と比較してアルミ箔ヒータの通電率を小さくすることができるので消費電力量の低減が可能となる。
【００２２】
また、圧縮機の急激な高低圧の変動はオイルの供給に支障を来たし、圧縮機の損傷に繋がる恐れがあるが回転数比率を最小限にすることにより回転数変化時の高低圧の変動を給油上問題がないレベルで抑えることが可能となる。
【００２３】
請求項７に記載の発明は、請求項１から請求項６のいずれか一項に記載の発明において、冷蔵庫の電動機の定格消費電力を６０Ｗ以下としたものであり、発熱の大きい素子が集積化しているパワー回路ブロックを流れる電流値を１Ａ以下に抑えることにより、パワー素子の小型化、ヒートシンクの小型化もしくは廃止が可能となり信頼性が著しく向上するとともに安価なインバータ基板の提供ができる。
【００２４】
請求項８に記載の発明は、請求項１から請求項７のいずれか一項に記載の発明において、定格内容積が２００Ｌ以下としたものであり、例えば一人暮らしの使用者向けの２００Ｌ以下の小型冷蔵庫の場合は外表面積が小さい分、放熱パイプの長さが短いため放熱パイプの温度が高くなり侵入熱量の影響がより大きくなるので、圧縮機の低能力時の放熱パイプ温度低減による吸熱量低減効果を得やすく、それにより消費電力量低減効果をより顕著に得られる。
【００２５】
また、吸熱量が小さいために圧縮機の最大能力を抑えることができるので冷蔵庫の電動機の定格消費電力が小さくなり、パワー素子の小型化、ヒートシンクの小型化もしくは廃止がより可能となり安価なインバータ基板の提供ができる。
【００２６】
請求項９に記載の発明は、請求項１から請求項８のいずれか一項に記載の発明において、冷蔵庫箱体断熱部に真空断熱材を備えたものであり、冷蔵庫の吸熱量をさらに下げることにより圧縮機の最大能力をさらに抑えることができるので冷蔵庫の電動機の定格消費電力が小さくなり、パワー素子の小型化、ヒートシンクの小型化もしくは廃止がより可能となり安価なインバータ基板の提供ができる。
【００２７】
請求項１０に記載の発明は、請求項１から請求項９のいずれか一項に記載の発明において、冷媒として可燃性冷媒を用いたものであり、圧縮機運転時に放熱パイプから庫内への侵入熱量を低減することにより、冷蔵室および冷凍室の温度を確保するために必要な冷却量を低減できるので冷媒封入量を削減でき、可燃性冷媒を用いた場合の安全性を向上することが可能となる。
【００２８】
【発明の実施の形態】
以下、本発明の実施の形態について図１から図１０を用いて説明する。
【００２９】
（実施の形態１）
図１は本発明の実施の形態１における冷蔵庫の概略図、図２は同実施の形態の冷蔵庫の概略断面図である。
【００３０】
図において、２８は冷蔵庫箱体であり、例えば上方部に比較的高温の区画である冷蔵室２６を、下方部に冷蔵室２６と図示しない断熱仕切りで区切られた比較的低温の冷凍室２７を配置しており、例えばウレタンのような断熱材で周囲と断熱した構成をしている。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。
【００３１】
冷蔵室２６は冷蔵保存のために通常１〜５℃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。
【００３２】
冷凍室２７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。
【００３３】
冷凍サイクル２９は圧縮機２１と放熱パイプ２２とキャピラリ２３と冷却器２４とを接続してある。冷却器２４は冷凍室２７の背面に位置し冷却器２４の近傍には冷却ファン２５が設けられている。また、冷蔵室２６の庫内には冷蔵室温度検知手段ＴＨ１を設け、冷蔵室温度検知手段ＴＨ１により圧縮機２１の運転を制御するものである。
【００３４】
冷凍サイクル２９の凝縮器としては、冷蔵庫断熱部内に配設された放熱パイプ２２のみで構成されている。つまり、圧縮機２１から出た吐出配管は機械室の空間を通りすぐに冷蔵庫断熱箱体内部の放熱パイプ２２に連結されている。そして、放熱パイプ２２は冷蔵庫外箱の断熱材側にアルミテープで固定されている。
【００３５】
また、冷蔵室２６、冷凍室２７奥面近傍には冷却ファン２５の作用により空気を循環させて庫内の冷却を行うために冷蔵室ダクト３０および冷凍室ダクト３１が配設されている。
【００３６】
冷却器２４の作用で低温になった冷凍室ダクト３１内の冷気は、冷凍室２７内に流入する冷気と冷蔵室ダクト３０を通り冷蔵室２６内に流入する冷気とに分流し、それぞれの庫内を冷却した後、再び冷却器２４へと吸い込まれる風路構成をとっている。
【００３７】
また、圧縮機２１は制御手段Ｃ１により、例えばインバータ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いる。
【００３８】
なお、圧縮機２１の回転数および運転停止の制御は、制御手段Ｃ１によりサーミスタである冷蔵室温度検知手段ＴＨ１の検出温度を基に制御する。
【００３９】
上記構成において、圧縮機２１の動作により吐出された高温高圧の冷媒は、放熱パイプ２２にて放熱して凝縮液化し、キャピラリ２３に至る。その後、キャピラリ２３で図示しないサクションラインと熱交換しながら減圧されて、冷却器２４に至り蒸発気化する。冷却器２４にて蒸発気化した冷媒は、図示しないサクションラインを経て圧縮機２１に吸入される。冷却器２４で冷やされた冷気は冷却ファン２５により冷凍室ダクト３１および冷蔵室ダクト３０を通り冷凍室２７、冷蔵室２６に送風される。そして、制御手段Ｃ１によりサーミスタである冷蔵室温度検知手段ＴＨ１の検出温度を基に圧縮機２１の回転数および運転停止、冷却ファン２５の制御を行い、冷蔵室２６を所定の温度に制御する。なお、冷凍室２７は、冷凍室ダクト３１および冷蔵室ダクト３０の風量配分により所定の温度になるように設定されている。
【００４０】
したがって、庫内の負荷変動に合わせて圧縮機２１の能力を可変できるので例えば扉開閉のない安定時には、圧縮機２１の回転数を下げることにより凝縮圧力も下がり、凝縮器としての放熱パイプ２２の温度を下げることができる。その結果、放熱パイプ２２から庫内への熱侵入を低減できるので、圧縮機２１の入力低減とともに省エネルギー化が図れる。
【００４１】
そして、内容積が２００Ｌ以下のいわゆる小型冷蔵庫の場合は、外表面積が小さい分、放熱パイプ２２の長さが短いので放熱パイプ２２の温度が高くなり侵入熱量の影響がさらに大きくなる傾向があり、圧縮機２１の低能力時の放熱パイプ温度低減による消費電力量低減効果がより顕著に得られる。
【００４２】
また、従来の、圧縮機が一定速型であり且つ圧縮機のＯＮ／ＯＦＦの制御を冷蔵室温度検知手段の検知温度で行い、冷凍室はダクトの風量分配により冷却する構成からなる冷蔵庫においては、ドア開閉や高外気温等、高負荷条件を考慮して圧縮機の能力設計を行っていたので例えば低外気温条件のように負荷が小さい時に極端に圧縮機の運転時間が低下し、冷凍室の庫内温度維持に必要な冷却量を確保できないという課題があった。また、放熱パイプは圧縮機運転時に高温となるために冷蔵庫外表面の結露防止の効果があるが、運転時間低下に伴って結露が生じやすくなるという課題もあった。
【００４３】
それに対して、本実施の形態の冷蔵庫では、低負荷条件時に圧縮機２１を最低回転数で運転することにより圧縮機２１を低い能力で運転できるので圧縮機２１の運転時間が延び冷凍室２７に必要な冷却量を確保することが可能となる。また、圧縮機２１の運転時間が延びるので冷蔵庫外表面温度が高くなる時間が長くなり、結露を防止することが可能となる。
【００４４】
なお、本実施の形態の冷蔵庫では、冷凍室２７に設けた冷却器２４と冷却ファン２５からの冷気を冷蔵室２６内に配分し、冷蔵室温度検知手段ＴＨ１により、冷蔵室２６の温度を検知して圧縮機２１の運転を制御し、冷蔵室２６内に自動ダンパーを設けていないので、低コスト化、省スペースを図れることはもちろんである。
【００４５】
また、圧縮機２１の能力可変手段をインバータによる回転数制御としたが、図示しない圧縮機のピストンのストロークを制御しても同様の効果が得られる。
【００４６】
（実施の形態２）
図３は本発明の実施の形態２における冷蔵庫の断面図であり、図４は同実施の形態のタイムチャートである。なお、実施の形態１と同一構成については詳細な説明を省略し、異なる部分のみ説明する。
【００４７】
冷蔵室ダクト仕切り３２は、冷蔵室内箱と共に冷蔵室ダクト３０を構成するものであり、例えばポリプロピレンで構成されている。アルミ箔ヒータ３３は、冷蔵室２６側の例えば冷蔵室ダクト仕切り３２に配設された温調用ヒータである。そして、インバータ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圧縮機２１とアルミ箔ヒータ３３は制御手段Ｃ２により回転数および通電を制御される。
【００４８】
アルミ箔ヒータ３３の通電制御方法を図４に示すタイムチャートにより説明する。
【００４９】
圧縮機２１停止中に、冷蔵室温度検知手段ＴＨ１が所定の温度ｔｈ２を検知すると圧縮機２１を起動する。この時、アルミ箔ヒータ３３の通電を停止する（Ｔ１）。圧縮機２１運転中に、冷蔵室温度検知手段ＴＨ１が所定の温度ｔｈ１以下を検知すると圧縮機２１を停止すると同時にアルミ箔ヒータ３３の通電を開始する（Ｔ２）。圧縮機２１停止中に、冷蔵室温度検知手段ＴＨ１が所定の温度ｔｈ２以上を検知すると圧縮機２１を起動すると同時にアルミ箔ヒータ３３の通電を停止する（Ｔ３）。アルミ箔ヒータ３３を圧縮機２１停止時に通電するのは、特に低外気温条件のように負荷が小さい時に圧縮機２１の運転時間が低下し、冷凍室７の庫内温度維持に必要な冷却量を確保できないので、強制的に冷蔵室２６庫内に熱負荷を与えて圧縮機２１の運転時間を引き伸ばし冷凍室２７の冷却量を確保するためである。
【００５０】
しかし、従来の能力一定型圧縮機では、高負荷条件を考慮して圧縮機の能力設計を行っていたので例えば低外気温条件のように負荷が小さい時に、極端に圧縮機の運転時間が低下し、アルミ箔ヒータ３３の通電時間が増大し消費電力量が増加するといった課題があった。
【００５１】
それに対して、本実施の形態の冷蔵庫では、圧縮機２１を能力可変型とすると低負荷条件時に圧縮機２１を最低回転数で運転することにより圧縮機２１を低い能力で運転できるので、圧縮機２１の運転時間が延び、停止時間が短くなるのでアルミ箔ヒータ３３の通電時間が減少し、大幅な消費電力量の削減が可能となる。
【００５２】
なお、圧縮機１の例えば更なる低回転化による低能力化により、アルミ箔ヒータ１３の廃止も可能であり、安価な冷蔵庫の提供ができる。
【００５３】
また、アルミ箔ヒータ３３を冷蔵室ダクト仕切り３２内に配設するとしたが、冷蔵室側内箱のウレタン側もしくは断熱仕切り３４内に配設しても、同様の効果が得られる。
【００５４】
（実施の形態３）
図５は本発明の実施の形態３における冷蔵庫の断面図である。図６は同実施の形態のタイムチャートである。なお、実施の形態１、２と同一構成については詳細な説明を省略し、異なる部分のみ説明する。
【００５５】
ＴＨ２は、外気温度を検知する例えばサーミスタである外気温度検知手段であり、例えば冷蔵庫箱体８の天面に配設されている。
【００５６】
図６に示すように、圧縮機２１運転中に、冷蔵室温度検知手段ＴＨ１が所定の温度ｔｈ１を検知すると圧縮機２１を停止すると同時にアルミ箔ヒータ３３の通電を開始する（Ｔ４）。この時、制御手段Ｃ３によりアルミ箔ヒータ３３の通電を通電率Ｘ％で行う。なお、この通電率Ｘ％は外気温度検知手段ＴＨ２の検知温度に依存する関数であり、外気温度が高いほどＸが小さくなる関数としてある。
【００５７】
従来、特に圧縮機の運転時間が短くなる低外気温時の冷凍室冷却量を確保するために、アルミ箔ヒータ３３を圧縮機の運転時間が長く冷凍室の冷却量を確保できる高外気温時にも圧縮機停止に１００％一定通電しており、無駄な熱量を冷蔵室庫内に与えていたために消費電力量の増大の要因となっていたが、外気温が高くなるとアルミ箔ヒータ３３を必要最小限の通電率で通電することにより無駄がなくなり大幅な消費電力量の低減が可能となる。
【００５８】
なお、外気温度検知手段ＴＨ２を冷蔵庫箱体２８の天面に配設するとしたが、冷蔵庫箱体２８の外表面（例えば側面やドア表面）や図示しない制御基板に配設しても同様の効果が得られる。
【００５９】
（実施の形態４）
図７は本発明の実施の形態４における冷蔵庫の断面図である。
【００６０】
図７に示すように、冷却ファン２５は冷凍室ダクト３１近傍に配設している。そのため、冷却ファン２５から吐出される風量が小さくなればなるほど、冷蔵室ダクト３０と冷凍室ダクト３１の風路抵抗を比較すると顕著に冷凍室ダクト３１の風路抵抗が小さくなり、全風量に占める冷凍室２７への風量比率が増加する。
【００６１】
また、同実施の形態の冷蔵庫の冷却ファン２５の電圧テーブルを（表１）に示す。
【００６２】
【表１】

【００６３】
外気温別に冷却ファン２５の最低使用電圧が制御され、制御手段Ｃ４で、外気温度検知手段ＴＨ２が所定の温度ｔｈ３以下を検知すると冷却ファン２５の印加電圧の最低値をＶ１として冷却ファン２５の運転を行い、ｔｈ３以上を検知すると最低値をＶ1より大きいＶ２とする。また、ｔｈ３以下の外気温時における冷却ファン２５の電圧の制御は冷蔵室温度検知手段ＴＨ１の検知温度により制御を行う。
【００６４】
従来、圧縮機のＯＮ／ＯＦＦを冷蔵室温度検知手段ＴＨ１で行っていたため、圧縮機の運転時間が短くなる低外気温時の冷凍室の冷却量を確保することが困難であったが、低外気温時に冷却ファン２５の印加電圧を落とし、冷却ファン２５からの吐出風量を小さくすると上記に示したように冷凍室２７の風量比率が大きくなり冷蔵室２６の風量比率が小さくなるので、冷凍室２７と冷蔵室２６の冷却量比率が冷凍室２７側に大きくなり、冷凍室２７の冷却量の確保が容易となる。そして、冷蔵室２６の冷却量比率が低下するので圧縮機２１の停止時間が短くなり、アルミ箔ヒータ３３の通電時間を短くすることができ消費電力量の大幅な削減が可能となる。
【００６５】
また、圧縮機２１を例えばインバータ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するとさらに低外気温時の圧縮機２１の運転時間を延ばすことができるので、アルミ箔ヒータ３３の通電時間を大幅に短くすることができ消費電力量をさらに大幅に削減できる。また、アルミ箔ヒータ３３の廃止も可能となる。
【００６６】
（実施の形態５）
図８は本発明の実施の形態５における冷蔵庫の運転状態を示すタイムチャートである。
【００６７】
圧縮機２１停止中に、冷蔵室温度検知手段ＴＨ１が所定の温度ｔｈ２以上を検知すると図示しない制御手段Ｃ５はこの信号を受け取り、圧縮機２１を回転数ＨＺ１で起動する（Ｔ５）。圧縮機２１を回転数ＨＺ１で運転中に、ドア開閉等により冷蔵庫庫内の温度がさらに上昇し、冷蔵室温度検知手段ＴＨ１が所定の温度ｔｈ４以上を検知すると図示しない制御手段Ｃ５はこの信号を受け取り、圧縮機２１の回転数をＨＺ２に引き上げる（Ｔ６）。圧縮機２１を回転数ＨＺ２で運転中に、庫内が冷却され冷蔵室温度検知手段ＴＨ１が所定の温度ｔｈ４以下を検知すると、圧縮機２１の回転数をＨＺ１に引き下げる（Ｔ７）。以上の動作を繰り返し、冷蔵室温度検知手段ＴＨ１が所定の温度ｔｈ２以下を検知すると、圧縮機２１を停止する（Ｔ８）。
【００６８】
このように、圧縮機２１の回転数を冷蔵室温度検知手段ＴＨ１の検知温度により２段階に変速させるものである。
【００６９】
従来の、圧縮機が多段変速型の場合は庫内負荷と連動して速やかに圧縮機の回転数を上げることができるので、負荷変動に対してフレキシブルに対応できるというメリットがある反面、圧縮比が大きく効率が悪い状態での運転時間が長くなるので消費電力量が大きくなるという課題があった。
【００７０】
しかし、本実施の形態の冷蔵庫では、圧縮機２１の回転数変化幅を２段階とし庫内負荷が極端に増大した場合のみ高速側の回転数ＨＺ２で運転し、基本は低速側の回転数ＨＺ１で運転することにより圧縮比が小さく効率が良い状態での運転時間を長く保てるので消費電力量を削減することが可能となる。
【００７１】
また、圧縮機２１の能力を速やかに上げていく多段変速型と比較して２段階にすることにより圧縮機２１の運転時間を延ばすことができるので、冷凍室２７に必要な冷却量を確保しやすくなり、従来と比較してアルミ箔ヒータ３３の通電率を小さくすることができるのでさらに消費電力量の低減が可能となる。
【００７２】
なお、本実施の形態では圧縮機２１の運転中に圧縮機２１の回転数を冷蔵室温度検知手段ＴＨ１の検知温度によりＵＰ、ＤＯＷＮさせるもので説明したが、一度高速側の回転数ＨＺ２にＵＰしたら圧縮機２１が停止するまでその回転数を維持し続けるという制御にしても同様の効果が得られる。
【００７３】
また、高速側の圧縮機２１の回転数ＨＺ２を低速側の回転数ＨＺ１の１．５倍以下に制御し、高速時の圧縮機１の冷却能力を最小限に抑えることにより、圧縮機２１の運転時間を最大限に延ばすことができる。その結果、冷凍室２７に必要な冷却量を確保しやすくなるので、従来と比較してアルミ箔ヒータ３３の通電率を小さくすることができ、消費電力量の低減が可能となる。
【００７４】
また、圧縮機２１の急激な高低圧の変動はオイルの供給に支障を来たし、圧縮機２１の損傷に繋がる恐れがあるが回転数比率を１．５倍以下にすることにより回転数変化時の高低圧の変動を給油上問題がないレベルで抑えることが可能となる。
【００７５】
また、本実施の形態では圧縮機２１の運転制御を冷蔵室温度検知手段ＴＨ１の検知温度により行なうもので説明したが、冷凍室内の温度で圧縮機２１の運転を制御し、冷蔵室には自動ダンパーを設けたものでも圧縮機の回転数変化幅を２段階、あるいは高速側の圧縮機２１の回転数ＨＺ２を低速側の回転数ＨＺ１の１．５倍以下に制御することによる作用、効果を得られる。
【００７６】
（実施の形態６）
図９は本発明の実施の形態６における冷蔵庫の運転制御装置の構成図である。３５は商用電源（図示せず）から圧縮機２１の能力を可変するための電源を作り出す電力変換部であり、例えばインバータや位相制御などの方法がある。電源変換部３５は、発熱の大きい素子（例えばダイオード、トランジスタなど）を集積化したパワー回路ブロック３６と、所定の電源を得るためにパワー回路ブロック３６の制御を行う電力変換制御部３７とからなる。３８はパワー回路ブロック３６の放熱を促進するヒートシンクである。
【００７７】
ここで、インバータによる回転数制御の場合は圧縮機２１の気筒容積の小容量化や高速側回転数の適正化により、圧縮機２１の冷凍能力すなわち消費電力を最小限化に抑え、冷蔵庫の電動機の定格消費電力を６０Ｗ以下とすることにより、パワー回路ブロック３６を流れる電流値を１Ａ以下に抑えることができる。これにより、パワー回路ブロック３６の温度上昇を抑えることができ、パワー素子の信頼性が著しく向上する。なお、電動機の定格消費電力とは周囲温度３０℃、圧縮機を連続運転とし冷蔵庫内を最も冷える状態にして安定した時の消費電力（入力）を言う。
【００７８】
また、従来例えば３Ａのパワー素子を使用していた場合、１Ａ用のパワー素子への小容量化が可能となり低コスト化が図れる。
【００７９】
また、ヒートシンク３８の小型化もしくは廃止も可能となり安価なインバータ基板の提供ができる。
【００８０】
なお、内容積が２００Ｌ以下のいわゆる小型冷蔵庫の場合は、外気からの吸熱負荷量が小さいために圧縮機２１の最大冷凍能力すなわち最大消費電力を抑えることが容易にできるので、パワー素子の小型化、ヒートシンク３８の小型化もしくは廃止がより安易に可能となる。
【００８１】
（実施の形態７）
図１０は本発明の実施の形態７における冷蔵庫の断面図である。
【００８２】
真空断熱材３９は、例えば冷蔵庫箱体２８背面の内箱と外箱の間に配設された、例えばシート状無機繊維集合体からなる芯材と前記芯材を覆うガスバリア性フィルムで構成されたものである。
【００８３】
冷蔵庫箱体２８の製造にあたっては、真空断熱材３９をあらかじめ例えば冷蔵庫外箱に直接的に接着固定したあと、硬質ウレタンフォームの原料を注入して一体発泡を行う。
【００８４】
真空断熱材３９により、冷蔵庫箱体２８の外気からの吸熱負荷量を低減できるので、圧縮機２１の最大冷凍能力すなわち最大消費電力を抑えることが容易にできるので、パワー素子の小型化、ヒートシンク３８の小型化もしくは廃止がより安易に可能となり安価なインバータ基板の提供ができる。
【００８５】
また、真空断熱材３９を取付けた側の冷蔵庫外箱の壁面温度を上げることができ冷蔵庫外箱の結露を防止することが可能となる。
【００８６】
なお、真空断熱材３９を冷蔵庫外箱に間接的に接着しても同様の効果が得られる。
【００８７】
また、真空断熱材３９を背面に配設するとしたが、冷蔵庫側面の内箱と放熱パイプ２２の間に真空断熱材３９を配設すると、圧縮機２１運転時の放熱パイプ２２から庫内への侵入熱量を低減できるので冷蔵室２６と冷凍室２７の庫内温度を維持するために必要な冷却負荷量が小さくなり、さらに圧縮機２１の最大冷凍能力すなわち最大消費電力を抑えることが可能となり、パワー素子の小型化、ヒートシンク３８の小型化もしくは廃止がさらに安易に可能となる。
【００８８】
（実施の形態８）
本発明の実施の形態８を図１を用いて説明する。
【００８９】
実施の形態１に示したように、圧縮機２１は制御手段Ｃ１により、例えばインバータ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いる。
【００９０】
冷蔵室温度検知手段ＴＨ１により検知した温度により、庫内の負荷変動に合わせて圧縮機２１の能力を可変できるので例えば扉開閉のない安定時には、圧縮機２１の能力を落とすことにより放熱パイプ２２の温度を下げることができる。
【００９１】
その結果、冷蔵室２６と冷凍室２７の庫内温度を維持するために必要な冷却負荷量が小さくなり、インバータによる回転数制御の場合は圧縮機２１の気筒容積の小容量化や高速側回転数の適正化により圧縮機２１の冷凍能力を最小限に抑えることが可能となる。
【００９２】
これにより、必要冷媒量の削減が可能となり冷媒として可燃性冷媒を可燃性冷媒を用いた場合の安全性を向上することが可能となる。また、実施の形態７に示したように真空断熱材を配設した冷蔵庫においては、冷蔵庫箱体２８の外気および放熱パイプ２２からの吸熱負荷量を低減できるので、さらに圧縮機２１の圧縮機２１の冷凍能力を最小限に抑えることが可能となり、さらに必要冷媒量が削減でき安全性を向上できる。
【００９３】
【発明の効果】
以上説明したように、本発明の請求項１に記載の発明は、冷蔵室、冷凍室を有し、冷凍サイクルの凝縮器が冷蔵庫箱体内に配設した放熱パイプのみで構成され、前記冷蔵室内に設置した冷蔵室温度検知手段により圧縮機の運転を制御する冷蔵庫において、圧縮機を能力可変型としたものであり、庫内の負荷変動に合わせて圧縮機の能力を可変できるので例えば扉開閉のない安定時には、圧縮機の能力を小さくすることにより高圧側圧力が下がり、凝縮器としての放熱パイプの温度を下げることができ、庫内への侵入熱量の低減が可能となり省エネルギー化が図れる。また、圧縮機を低い能力で運転することで圧縮機の運転時間を延ばすことができ冷凍室に必要な冷却量を確保することが可能となる。また、圧縮機の運転時間が延びるので放熱パイプによる冷蔵庫外表面の結露防止効果が大きくなる。
【００９４】
また、請求項２に記載の発明は、請求項１に記載の発明において、冷蔵室側ウレタン内もしくは冷蔵室庫内に冷蔵室を加熱するヒータを設け、圧縮機停止時に通電するものであり、低外気温時、冷凍室温度を確保できるとともに、圧縮機を低い能力で運転することで圧縮機停止時間を減らし、ヒータの通電率を小さくすることができ、消費電力量の低減が可能となる。
【００９５】
また、請求項３に記載の発明は、請求項２に記載の発明において、外気温度検知手段により検知した温度によりヒータの通電率を制御するものであり、周囲温度に適したヒータの通電が可能となり、従来、特に圧縮機の運転時間が短くなる低外気温時の冷凍室の冷却量を確保するためにアルミ箔ヒータを圧縮機の運転時間が長い高外気温時にも圧縮機停止時に１００％一定通電しており、無駄な熱量を冷蔵室庫内に与えていたために消費電力量の増大の要因となっていたが、外気温が高くなるとアルミ箔ヒータを必要最小限の通電率で通電することにより無駄がなくなり大幅な消費電力量の低減が可能となる。
【００９６】
また、請求項４に記載の発明は、請求項１から請求項３のいずれか一項に記載の発明において、外気温温度検知手段により検知した温度により、ファンの回転数を可変するものであり、低外気温時にファンの回転数つまり送風量を下げると、冷凍室の風量比率が大きくなり冷蔵室の風量比率が小さくなるので、冷凍室と冷蔵室の冷却量比率が冷凍室側に大きくなり、冷凍室の冷却量の確保が容易となる。また、冷蔵室の冷却量比率が低下するので圧縮機の停止時間が短くなり、アルミ箔ヒータの通電時間を短くすることができ消費電力量の削減が可能となる。
【００９７】
また、請求項５に記載の発明は、請求項１から請求項４のいずれか一項に記載の発明において、能力可変型圧縮機の回転数を２段階制御としたものであり、多段変速型の場合は庫内負荷と連動して速やかに圧縮機の回転数を上げることができるので、負荷変動に対してフレキシブルに対応できるというメリットがある反面、圧縮比が大きく効率が悪い状態での運転時間が長くなるので消費電力量が大きくなるという課題があったが、圧縮機の回転数変化幅を２段階とし庫内負荷が極端に増大した場合のみ、高速側の回転数で運転し、基本は低速側の回転数で運転することにより圧縮比が小さく効率が良い状態での運転時間を長くできるので消費電力量を削減することが可能となる。また、圧縮機の能力を速やかに上げていく多段変速型と比較して２段階にすることにより圧縮機の運転時間を延ばすことができるので、冷凍室に必要な冷却量を確保しやすくなるので、従来と比較してアルミ箔ヒータの通電率を小さくすることができ、消費電力量の低減が可能となる。
【００９８】
また、請求項６に記載の発明は、請求項５に記載の発明において、能力可変型圧縮機の回転数の低速側と高速側の回転数比を１．５倍以下としたものであり、高速時の圧縮機の冷却能力を最小限に抑えることにより、圧縮機の運転時間を最大限にまで延ばすことができ、冷凍室に必要な冷却量を確保しやすくなるので、従来と比較してアルミ箔ヒータの通電率を小さくすることができるので消費電力量の低減が可能となる。また、圧縮機の急激な高低圧の変動はオイルの供給に支障を来たし、圧縮機の損傷に繋がる恐れがあるが回転数比率を最小限にすることにより回転数変化時の高低圧の変動を給油上問題がないレベルで抑えることが可能となる。
【００９９】
また、請求項７に記載の発明は、請求項１から請求項６のいずれか一項に記載の発明において、冷蔵庫の電動機の定格消費電力を６０Ｗ以下としたものであり、発熱の大きい素子が集積化しているパワー回路ブロックを流れる電流値を１Ａ以下に抑えることにより、パワー素子の小型化、ヒートシンクの小型化もしくは廃止が可能となり信頼性が著しく向上するとともに安価なインバータ基板の提供ができる。
【０１００】
また、請求項８に記載の発明は、請求項１から請求項７のいずれか一項に記載の発明において、定格内容積が２００Ｌ以下としたものであり、例えば一人暮らしの使用者向けの２００Ｌ以下の小型冷蔵庫の場合は外表面積が小さい分、放熱パイプの長さが短いため放熱パイプの温度が高くなり侵入熱量の影響がより大きくなるので、圧縮機の低能力時の放熱パイプ温度低減による吸熱量低減効果を得やすく、それにより消費電力量低減効果をより顕著に得られる。また、吸熱量が小さいために圧縮機の最大能力を抑えることができるので冷蔵庫の電動機の定格消費電力が小さくなり、パワー素子の小型化、ヒートシンクの小型化もしくは廃止がより可能となり安価なインバータ基板の提供ができる。
【０１０１】
また、請求項９に記載の発明は、請求項１から請求項８のいずれか一項に記載の発明において、冷蔵庫箱体断熱部に真空断熱材を備えたものであり、冷蔵庫の吸熱量をさらに下げることにより圧縮機の最大能力をさらに抑えることができるので冷蔵庫の電動機の定格消費電力が小さくなり、パワー素子の小型化、ヒートシンクの小型化もしくは廃止がより可能となり安価なインバータ基板の提供ができる。
【０１０２】
また、請求項１０に記載の発明は、請求項１から請求項９のいずれか一項に記載の発明において、冷媒として可燃性冷媒を用いたものであり、圧縮機運転時に放熱パイプから庫内への侵入熱量を低減することにより、冷蔵室および冷凍室の温度を確保するために必要な冷却量を低減できるので冷媒封入量を削減でき、可燃性冷媒を用いた場合の安全性を向上することが可能となる。
【図面の簡単な説明】
【図１】本発明の実施の形態１の冷蔵庫の概略図
【図２】同実施の形態の冷蔵庫の断面図
【図３】本発明の実施の形態２の冷蔵庫の断面図
【図４】同実施の形態の冷蔵庫のタイムチャート
【図５】本発明の実施の形態３の冷蔵庫の断面図
【図６】同実施の形態の冷蔵庫のタイムチャート
【図７】本発明の実施の形態４の冷蔵庫の断面図
【図８】本発明の実施の形態５の冷蔵庫の運転状態を示すタイムチャート
【図９】本発明の実施の形態６の冷蔵庫の運転制御装置の構成図
【図１０】本発明の実施の形態７の冷蔵庫の断面図
【図１１】従来の冷蔵庫の概略図
【符号の説明】
２１圧縮機
２２放熱パイプ
２５冷却ファン
２６冷蔵室
２７冷凍室
２８冷蔵庫箱体
２９冷凍サイクル
３３アルミ箔ヒータ
３９真空断熱材
ＴＨ１冷蔵室温度検知手段
ＴＨ２外気温度検知手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to energy saving of refrigerators.
[0002]
[Prior art]
2. Description of the Related Art In recent years, refrigerators in which a radiating pipe as a condenser of a cooling system is disposed in a refrigerator box have become widespread (for example, see Patent Document 1).
[0003]
FIG. 11 shows a schematic diagram of a conventional cooling cycle and a refrigerator.
[0004]
The main body 2 of the refrigerator 1 includes an outer case 3 made of a steel plate opening forward, an inner case 4 made of a synthetic resin opening forward, which is incorporated in the outer case 3 with a space therebetween, and And a foamed polyurethane insulation material 5 filled and foamed between the inner boxes 4. The inner box 4 is divided into four upper and lower sections by horizontal partition portions (6a, 6b, 6c) that partition vertically, and a storage room is formed. The refrigerator compartment 11 is located at the top, the vegetable compartment 12 is located at the second stage, the ice making room 13A is located at the third stage, and the switching room 13B is also located at the right side, and the freezing room 14 is located at the fourth stage. A vertical partition wall 15 is provided between them.
[0005]
On the opening side of each of these storage rooms, doors (not shown) are provided which are openably and closably sealed corresponding to the respective storage rooms, and door gaskets (not shown) are provided on each of the doors to seal the inside and the outside air. Have been.
[0006]
Condensation may occur due to the difference between the inside temperature and the outside air temperature between the door gasket and the front portion 16 around the opening on the main body side. In order to prevent this dew condensation, a radiating pipe 8 is provided. In addition, the refrigerator compartment 11 and the vegetable compartment 12 are kept in the refrigeration temperature zone, and the ice making compartment 13A and the freezing compartment 14 are kept in the freezing temperature zone. In the switching room 13B, the temperature inside the refrigerator can be selected.
[0007]
The heat radiating pipe 8 is provided with a pipe through which a high-temperature refrigerant discharged from a compressor (not shown) provided in the machine room flows through the opening of the freezing room 14 and the ice making room 13A where the difference between the inside temperature and the outside air temperature is large. And a pipe whose temperature has decreased due to the progress of heat radiation is arranged at the opening of the refrigerator compartment 11 having a small temperature difference.
[0008]
This makes it possible to appropriately distribute the amount of heat appropriate to prevent dew condensation occurring around each temperature zone chamber.
[0009]
[Patent Document 1]
JP-A-2002-62023
[0010]
[Problems to be solved by the invention]
However, the above-described conventional configuration has a configuration in which the radiating pipe 8 through which the high-temperature refrigerant discharged from the compressor flows although the dew condensation is suppressed is disposed around the freezing room 14 where the temperature difference from the radiating pipe 8 is large. In addition, there is a problem that the amount of heat entering the freezer compartment 14 from the heat radiating pipe 8 during the operation of the compressor becomes extremely large, and the energy consumption becomes large.
[0011]
Conventionally, refrigerators that are often used in refrigerators of 200 L or less have a heat-dissipating pipe provided only in the refrigerator box in order to save space by reducing costs and improving volumetric efficiency. In such a refrigerator, a condenser is arranged in the machine room to radiate heat to the outside of the refrigerator, and then compared to a refrigerator in which the heat is radiated by a radiating pipe in the refrigerator box, the radiating pipe is operated from the radiating pipe during the compressor operation. The problem was that the amount of heat that penetrated into the interior was large.
[0012]
Further, conventionally, in a so-called small refrigerator of 200 L or less, in order to reduce costs, cool air provided from a cooler and a cooling fan provided in a freezing room is distributed to the cold room, and the temperature of the cold room is detected. Some compressors control the operation of the compressor and do not have an automatic damper in the refrigerator compartment. In such a refrigerator, since the temperature of the refrigerator compartment is controlled with priority, for example, when the ambient temperature decreases, the temperature rise in the refrigerator compartment due to heat absorption from the surroundings decreases, and the operating rate of the compressor decreases. Thus, there has been a problem that the temperature of the freezing compartment cannot be maintained at a predetermined temperature. In order to solve the problem, a heater is provided in the refrigerating chamber, and heating is performed when the compressor is stopped.
[0013]
The present invention has been made to solve the conventional problem, and an object of the present invention is to save energy of a so-called small refrigerator of 200 L or less.
[0014]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention has a refrigerator compartment and a freezer compartment, and a condenser of a refrigerating cycle is constituted only by a heat radiating pipe arranged in a refrigerator box body. In a refrigerator in which the operation of the compressor is controlled by the detection means, the capacity of the compressor is variable, and the capacity of the compressor can be changed according to the load fluctuation in the refrigerator. By reducing the capacity of the machine, the high-pressure side pressure is reduced, the temperature of the radiating pipe as a condenser can be reduced, and the amount of heat entering the refrigerator can be reduced, thereby conserving energy. In addition, by operating the compressor with a low capacity, the operation time of the compressor can be extended, and the required cooling amount in the freezing room can be secured.
[0015]
In addition, since the operation time of the compressor is extended, the effect of preventing condensation on the outer surface of the refrigerator by the heat radiating pipe is increased.
[0016]
According to a second aspect of the present invention, in the first aspect of the invention, a heater for heating the refrigerating compartment is provided in the refrigerating compartment side urethane or the refrigerating compartment storage, and electricity is supplied when the compressor is stopped. At the time of air temperature, the freezing room temperature can be ensured, and the compressor can be operated with a low capacity, so that the compressor stop time can be reduced, the power supply rate of the heater can be reduced, and the power consumption can be reduced.
[0017]
According to a third aspect of the present invention, in the second aspect of the present invention, the energization rate of the heater is controlled by the temperature detected by the outside air temperature detection means, and the energization of the heater suitable for the ambient temperature can be performed. Conventionally, in order to secure the cooling amount of the freezing room at low outside air temperature, especially when the operation time of the compressor is short, the aluminum foil heater is energized at 100% constant when the compressor is stopped even at the high outside air temperature when the operation time of the compressor is long. The waste heat was given to the refrigerator compartment, which caused an increase in power consumption.However, when the outside air temperature increased, the aluminum foil heater was energized with the minimum necessary energization rate. There is no waste, and it is possible to greatly reduce the power consumption.
[0018]
According to a fourth aspect of the present invention, in the first aspect of the invention, the number of revolutions of the fan is varied according to the temperature detected by the outside air temperature detecting means. When the rotation speed of the fan, that is, the air flow rate is reduced at the outside temperature, the air volume ratio of the freezer compartment becomes larger and the air volume ratio of the refrigerator compartment becomes smaller. It is easy to secure the cooling amount of the chamber. In addition, since the cooling amount ratio of the refrigerator compartment is reduced, the stop time of the compressor is shortened, the energization time of the aluminum foil heater can be shortened, and the power consumption can be reduced.
[0019]
The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the rotational speed of the variable capacity compressor is controlled in two stages, and in the case of a multi-speed transmission type. Has the advantage of being able to flexibly respond to load fluctuations because it can quickly increase the number of rotations of the compressor in conjunction with the internal load.However, the operating time when the compression ratio is large and the efficiency is low is low. There was a problem that the power consumption would increase because of the lengthening of the compressor. However, the compressor was operated at the high-speed rotation speed only when the load in the refrigerator was extremely increased with two stages of change in the rotation speed of the compressor. By operating at the rotation speed on the side, the operation time in a state where the compression ratio is small and the efficiency is good can be lengthened, so that the power consumption can be reduced.
[0020]
In addition, since the operation time of the compressor can be extended by setting it to two stages as compared with the multi-stage transmission type in which the capacity of the compressor is quickly increased, it is easy to secure the necessary cooling amount in the freezing room. In addition, compared to the conventional case, the duty ratio of the aluminum foil heater can be reduced, and the power consumption can be reduced.
[0021]
According to a sixth aspect of the present invention, in the invention of the fifth aspect, the ratio of the low-speed side to the high-speed side of the rotational speed of the variable capacity compressor is 1.5 times or less. By minimizing the cooling capacity of the compressor, the operating time of the compressor can be extended to the maximum, and it becomes easier to secure the required cooling amount in the freezing room. Since the energization rate of the heater can be reduced, the amount of power consumption can be reduced.
[0022]
In addition, rapid fluctuations in high and low pressure of the compressor may hinder oil supply and may lead to damage to the compressor.However, by minimizing the rotation speed ratio, fluctuations in high and low pressure when the rotation speed changes are reduced. It is possible to reduce the level at which there is no problem in refueling.
[0023]
The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the rated power consumption of the electric motor of the refrigerator is 60 W or less. By suppressing the current value flowing through the power circuit block to 1 A or less, it is possible to downsize the power element and downsize or eliminate the heat sink, thereby significantly improving the reliability and providing an inexpensive inverter board.
[0024]
The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the rated internal volume is 200 L or less, for example, a small size of 200 L or less for a single-user. In the case of a refrigerator, the heat radiation pipe temperature rises due to the short heat radiation pipe due to the small external surface area, and the influence of the amount of heat entering increases, so the heat absorption amount is reduced by lowering the heat radiation pipe temperature when the compressor has low capacity. The effect can be easily obtained, and the effect of reducing the power consumption can be more remarkably obtained.
[0025]
In addition, since the maximum capacity of the compressor can be suppressed due to the small amount of heat absorption, the rated power consumption of the electric motor of the refrigerator is reduced, and it is possible to reduce the size of the power element, the size of the heat sink, or abolish the heat sink. Can be provided.
[0026]
According to a ninth aspect of the present invention, in the invention according to any one of the first to eighth aspects, the refrigerator box heat insulating portion is provided with a vacuum heat insulating material to further reduce the heat absorption of the refrigerator. As a result, the maximum capacity of the compressor can be further suppressed, so that the rated power consumption of the electric motor of the refrigerator is reduced, the size of the power element, the size of the heat sink, or the elimination of the heat sink can be further reduced, so that an inexpensive inverter board can be provided.
[0027]
According to a tenth aspect of the present invention, in the invention according to any one of the first to ninth aspects, a flammable refrigerant is used as the refrigerant. By reducing the amount of heat that enters, it is possible to reduce the amount of cooling required to secure the temperatures of the refrigerator compartment and the freezer compartment, thereby reducing the amount of charged refrigerant and improving safety when using flammable refrigerants. It becomes possible.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0029]
(Embodiment 1)
FIG. 1 is a schematic diagram of a refrigerator according to Embodiment 1 of the present invention, and FIG. 2 is a schematic sectional view of the refrigerator of the embodiment.
[0030]
In the drawing, reference numeral 28 denotes a refrigerator box, for example, a refrigerator compartment 26 which is a relatively high temperature compartment in an upper portion, and a refrigerator compartment 26 in a lower portion which is separated from the refrigerator compartment 26 by a heat insulating partition (not shown). They are arranged and insulated from the surroundings by a heat insulating material such as urethane. Loading and unloading of stored items such as food is performed via an insulated door (not shown).
[0031]
The refrigerating compartment 26 is usually set at 1 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, about 10 ° C., for freshening wine or root vegetables.
[0032]
The freezing room 27 is usually 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.
[0033]
The refrigeration cycle 29 connects the compressor 21, the heat radiation pipe 22, the capillary 23, and the cooler 24. The cooler 24 is located on the back of the freezing room 27 and a cooling fan 25 is provided near the cooler 24. The refrigerator compartment temperature detecting means TH1 is provided inside the refrigerator compartment 26, and the operation of the compressor 21 is controlled by the refrigerator compartment temperature detecting means TH1.
[0034]
The condenser of the refrigeration cycle 29 includes only the radiating pipe 22 provided in the refrigerator heat insulating part. That is, the discharge pipe coming out of the compressor 21 passes through the space in the machine room and is connected to the heat radiating pipe 22 inside the refrigerator heat insulating box. The heat radiating pipe 22 is fixed to the heat insulating material side of the outer box of the refrigerator with aluminum tape.
[0035]
Further, a refrigerator compartment duct 30 and a freezer compartment duct 31 are provided near the inner surface of the refrigerator compartment 26 and the freezer compartment 27 to circulate air by the action of the cooling fan 25 to cool the inside of the refrigerator.
[0036]
The cool air in the freezer compartment duct 31 that has become low temperature by the action of the cooler 24 is divided into cold air flowing into the freezer compartment 27 and cold air flowing into the refrigerator compartment 26 through the refrigerator compartment duct 30. After the inside is cooled, the air passage is drawn into the cooler 24 again.
[0037]
Further, the compressor 21 is of a variable capacity type that can change the refrigeration capacity by controlling the amount of circulating refrigerant by controlling the number of revolutions by an inverter, for example, by the control means C1.
[0038]
The control of the rotation speed and the operation stop of the compressor 21 is controlled by the control means C1 based on the temperature detected by the refrigerator temperature detecting means TH1 which is a thermistor.
[0039]
In the above configuration, the high-temperature and high-pressure refrigerant discharged by the operation of the compressor 21 radiates heat in the radiating pipe 22 to be condensed and liquefied, and reaches the capillary 23. After that, the pressure is reduced while exchanging heat with a suction line (not shown) by the capillary 23, and reaches the cooler 24 to evaporate. The refrigerant evaporated and vaporized by the cooler 24 is sucked into the compressor 21 via a suction line (not shown). The cool air cooled by the cooler 24 is sent by the cooling fan 25 to the freezer room 27 and the refrigerator room 26 through the freezer room duct 31 and the refrigerator room duct 30. The control means C1 controls the rotation speed and operation stop of the compressor 21 and the control of the cooling fan 25 based on the temperature detected by the refrigerator temperature detecting means TH1, which is a thermistor, and controls the refrigerator chamber 26 to a predetermined temperature. The freezing room 27 is set to a predetermined temperature by the air volume distribution of the freezing room duct 31 and the refrigerating room duct 30.
[0040]
Therefore, since the capacity of the compressor 21 can be changed in accordance with the load fluctuation in the refrigerator, for example, when the door 21 is stable without opening and closing the door, the condensing pressure is lowered by lowering the rotation speed of the compressor 21 and the heat radiation pipe 22 as a condenser is reduced. Temperature can be reduced. As a result, heat intrusion from the heat radiating pipe 22 into the storage can be reduced, so that the input of the compressor 21 can be reduced and energy can be saved.
[0041]
Then, in the case of a so-called small refrigerator having an internal volume of 200 L or less, the length of the heat radiating pipe 22 is shorter due to the smaller outer surface area, so that the temperature of the heat radiating pipe 22 tends to be higher, and the influence of the amount of invading heat tends to be further increased. The effect of reducing the power consumption by reducing the temperature of the heat radiating pipe when the compressor 21 has a low capacity can be more remarkably obtained.
[0042]
Further, in a conventional refrigerator having a configuration in which the compressor is of a constant speed type and the ON / OFF control of the compressor is performed based on the temperature detected by the refrigerator temperature detecting means, and the freezing room is cooled by distributing the air volume of the duct. Since the compressor capacity was designed in consideration of high load conditions such as opening and closing doors and high outside air temperature, the operating time of the compressor was extremely reduced when the load was small, for example, in low outside air temperature conditions. There was a problem that it was not possible to secure the cooling amount required for maintaining the temperature in the refrigerator. In addition, since the heat radiating pipe becomes high in temperature during the operation of the compressor, it has an effect of preventing dew condensation on the outer surface of the refrigerator, but there is also a problem that dew condensation easily occurs as the operation time is reduced.
[0043]
On the other hand, in the refrigerator of the present embodiment, the compressor 21 can be operated at a low capacity by operating the compressor 21 at the minimum rotation speed under a low load condition. The required amount of cooling can be secured. Further, since the operation time of the compressor 21 is extended, the time during which the outer surface temperature of the refrigerator becomes high is lengthened, so that dew condensation can be prevented.
[0044]
In the refrigerator of the present embodiment, the cool air from the cooler 24 and the cooling fan 25 provided in the freezing room 27 is distributed into the refrigerator 26, and the temperature of the refrigerator 26 is detected by the refrigerator temperature detecting means TH1. In addition, since the operation of the compressor 21 is controlled and no automatic damper is provided in the refrigerator compartment 26, it is of course possible to reduce the cost and space.
[0045]
In addition, although the capacity varying means of the compressor 21 is controlled by the rotation speed by the inverter, the same effect can be obtained by controlling the stroke of the piston of the compressor not shown.
[0046]
(Embodiment 2)
FIG. 3 is a cross-sectional view of a refrigerator according to Embodiment 2 of the present invention, and FIG. 4 is a time chart of the embodiment. The detailed description of the same configuration as in the first embodiment will be omitted, and only different portions will be described.
[0047]
The refrigerator compartment duct partition 32 constitutes the refrigerator compartment duct 30 together with the refrigerator compartment box, and is made of, for example, polypropylene. The aluminum foil heater 33 is a heater for temperature control provided in, for example, the refrigerator compartment duct partition 32 on the refrigerator compartment 26 side. The variable speed compressor 21 and the aluminum foil heater 33 that can change the refrigeration capacity by controlling the amount of circulating refrigerant by controlling the rotation speed by an inverter are controlled by the control means C2 to control the rotation speed and energization.
[0048]
A method for controlling the energization of the aluminum foil heater 33 will be described with reference to a time chart shown in FIG.
[0049]
When the refrigerator compartment temperature detecting means TH1 detects the predetermined temperature th2 while the compressor 21 is stopped, the compressor 21 is started. At this time, the energization of the aluminum foil heater 33 is stopped (T1). When the refrigerator compartment temperature detecting means TH1 detects the predetermined temperature th1 or less during the operation of the compressor 21, the compressor 21 is stopped, and at the same time, the energization of the aluminum foil heater 33 is started (T2). When the refrigerator compartment temperature detecting means TH1 detects the predetermined temperature th2 or more while the compressor 21 is stopped, the compressor 21 is started and at the same time, the energization of the aluminum foil heater 33 is stopped (T3). The reason why the aluminum foil heater 33 is energized when the compressor 21 is stopped is that the operation time of the compressor 21 is reduced particularly when the load is small such as a low outside air temperature condition, and the amount of cooling required for maintaining the temperature in the freezer 7. Therefore, a thermal load is forcibly applied to the refrigerator compartment 26 to extend the operation time of the compressor 21 and secure the cooling amount of the freezing compartment 27.
[0050]
However, in the conventional fixed capacity compressor, the capacity of the compressor was designed in consideration of high load conditions, so that when the load was small, for example, in a low outside air temperature condition, the operation time of the compressor was extremely reduced. However, there has been a problem that the energization time of the aluminum foil heater 33 increases and the amount of power consumption increases.
[0051]
On the other hand, in the refrigerator according to the present embodiment, when the compressor 21 is of a variable capacity type, the compressor 21 can be operated at a low capacity by operating the compressor 21 at the minimum rotation speed under a low load condition. Since the operation time of the heater 21 is extended and the stop time is shortened, the energization time of the aluminum foil heater 33 is reduced, and the power consumption can be significantly reduced.
[0052]
It should be noted that the aluminum foil heater 13 can be abolished by lowering the capacity of the compressor 1 by, for example, lowering the rotation further, and an inexpensive refrigerator can be provided.
[0053]
Although the aluminum foil heater 33 is provided in the refrigerator compartment duct partition 32, the same effect can be obtained by providing it in the urethane side of the refrigerator compartment inner box or in the heat insulation partition 34.
[0054]
(Embodiment 3)
FIG. 5 is a sectional view of a refrigerator according to Embodiment 3 of the present invention. FIG. 6 is a time chart of the embodiment. The detailed description of the same configuration as the first and second embodiments will be omitted, and only different portions will be described.
[0055]
TH2 is an outside air temperature detecting means which is, for example, a thermistor for detecting the outside air temperature, and is disposed on the top surface of the refrigerator box 8, for example.
[0056]
As shown in FIG. 6, when the refrigerator compartment temperature detecting means TH1 detects a predetermined temperature th1 during the operation of the compressor 21, the compressor 21 is stopped, and at the same time, the energization of the aluminum foil heater 33 is started (T4). At this time, the energization of the aluminum foil heater 33 is performed at an energization rate of X% by the control means C3. The duty ratio X% is a function that depends on the temperature detected by the outside air temperature detecting means TH2, and is a function in which X decreases as the outside air temperature increases.
[0057]
Conventionally, in order to secure the cooling amount of the freezing room at a low outside temperature when the operating time of the compressor is particularly short, the aluminum foil heater 33 is operated at a high outside temperature at which the operating time of the compressor is long and the cooling amount of the freezing room can be secured. Also, 100% constant electricity was supplied to the compressor stoppage, and the amount of waste heat was given to the refrigerator compartment, which caused an increase in power consumption. However, when the outside air temperature increased, the aluminum foil heater 33 was required. By energizing at the minimum energizing rate, waste is eliminated and a significant reduction in power consumption becomes possible.
[0058]
Although the outside air temperature detecting means TH2 is arranged on the top surface of the refrigerator box 28, the same effect can be obtained by disposing it on the outer surface (for example, a side surface or a door surface) of the refrigerator box 28 or a control board (not shown). Is obtained.
[0059]
(Embodiment 4)
FIG. 7 is a sectional view of a refrigerator according to Embodiment 4 of the present invention.
[0060]
As shown in FIG. 7, the cooling fan 25 is provided near the freezer compartment duct 31. Therefore, the smaller the air volume discharged from the cooling fan 25 is, the more significantly the air channel resistance of the freezer compartment duct 31 and that of the freezer compartment duct 31 are compared. The air volume ratio to the freezer compartment 27 increases.
[0061]
Also, (Table 1) shows a voltage table of the cooling fan 25 of the refrigerator of the embodiment.
[0062]
[Table 1]

[0063]
The minimum use voltage of the cooling fan 25 is controlled according to the outside air temperature, and when the outside air temperature detection means TH2 detects a predetermined temperature th3 or less by the control means C4, the lowest value of the voltage applied to the cooling fan 25 is set to V1 to operate the cooling fan 25. Is performed, and when th3 or more is detected, the minimum value is set to V2 larger than V1. The control of the voltage of the cooling fan 25 at the time of the outside air temperature equal to or less than th3 is performed based on the temperature detected by the refrigerator compartment temperature detecting means TH1.
[0064]
Conventionally, since the ON / OFF of the compressor has been performed by the refrigerator temperature detecting means TH1, it has been difficult to secure the cooling amount of the freezer at the time of low outside air temperature, in which the operation time of the compressor is shortened. When the voltage applied to the cooling fan 25 is reduced at the time of the outside air temperature and the amount of air discharged from the cooling fan 25 is reduced, the air volume ratio of the freezer compartment 27 increases and the air volume ratio of the refrigerator compartment 26 decreases as described above. The ratio of the amount of cooling between the refrigeration compartment 27 and the refrigeration compartment 26 increases toward the freezing compartment 27, which facilitates the securing of the cooling capacity of the freezing compartment 27. Since the cooling amount ratio of the refrigerating chamber 26 is reduced, the stop time of the compressor 21 is shortened, the energization time of the aluminum foil heater 33 can be shortened, and the power consumption can be greatly reduced.
[0065]
Further, if the compressor 21 is of a variable capacity type that can change the refrigeration capacity by controlling the refrigerant circulation amount by controlling the rotation speed by an inverter, for example, the operation time of the compressor 21 at a low outside air temperature can be further extended. Thus, the energizing time of the aluminum foil heater 33 can be greatly reduced, and the power consumption can be further reduced. Further, the aluminum foil heater 33 can be eliminated.
[0066]
(Embodiment 5)
FIG. 8 is a time chart showing an operation state of the refrigerator in the fifth embodiment of the present invention.
[0067]
If the refrigerator compartment temperature detecting means TH1 detects a predetermined temperature th2 or more while the compressor 21 is stopped, the control means C5 (not shown) receives this signal and starts the compressor 21 at the rotation speed HZ1 (T5). While the compressor 21 is operating at the rotation speed HZ1, the temperature in the refrigerator is further increased by opening and closing the door and the like, and when the refrigerator compartment temperature detecting means TH1 detects a predetermined temperature th4 or more, the control means C5 (not shown) outputs this signal. Upon receipt, the rotation speed of the compressor 21 is increased to HZ2 (T6). During operation of the compressor 21 at the rotation speed HZ2, when the inside of the refrigerator is cooled and the refrigerator compartment temperature detection means TH1 detects a predetermined temperature th4 or lower, the rotation speed of the compressor 21 is reduced to HZ1 (T7). The above operation is repeated, and when the refrigerator compartment temperature detecting means TH1 detects the predetermined temperature th2 or lower, the compressor 21 is stopped (T8).
[0068]
As described above, the rotation speed of the compressor 21 is shifted in two stages based on the temperature detected by the refrigerator temperature detecting means TH1.
[0069]
In the case of conventional multi-speed compressors, the number of rotations of the compressor can be quickly increased in conjunction with the load in the refrigerator, so that there is an advantage that the compressor can flexibly cope with load fluctuations, but the compression ratio However, there is a problem that the power consumption increases because the operating time in a state where the efficiency is low and the efficiency is low becomes long.
[0070]
However, the refrigerator of the present embodiment operates at the high-speed rotation speed HZ2 only when the load in the refrigerator is extremely increased by setting the rotation speed of the compressor 21 to two steps, and basically the low-speed rotation speed HZ1. By operating at, the operation time in a state where the compression ratio is small and the efficiency is good can be kept long, so that the power consumption can be reduced.
[0071]
In addition, since the operation time of the compressor 21 can be extended by setting it to two stages as compared with the multi-speed type in which the capacity of the compressor 21 is quickly increased, the required cooling amount for the freezing room 27 is secured. The power consumption of the aluminum foil heater 33 can be reduced as compared with the related art, so that the power consumption can be further reduced.
[0072]
In the present embodiment, the rotation speed of the compressor 21 during the operation of the compressor 21 is described as being UP and DOWN based on the temperature detected by the refrigerator compartment temperature detection means TH1, but once the rotation speed HZ2 on the high speed side is increased. Then, the same effect can be obtained by controlling the compressor 21 to keep the rotation speed until the compressor 21 stops.
[0073]
In addition, the rotation speed HZ2 of the high-speed side compressor 21 is controlled to 1.5 times or less of the low-speed side rotation speed HZ1, and the cooling capacity of the compressor 1 at high speed is minimized. Operation time can be maximized. As a result, the required cooling amount in the freezing room 27 can be easily secured, so that the duty ratio of the aluminum foil heater 33 can be reduced as compared with the related art, and the power consumption can be reduced.
[0074]
Also, a sudden change in the high and low pressures of the compressor 21 hinders the oil supply and may lead to damage to the compressor 21. Fluctuations in high and low pressure can be suppressed to a level at which there is no problem in refueling.
[0075]
Further, in the present embodiment, the operation control of the compressor 21 is described based on the detection temperature of the refrigerator compartment temperature detecting means TH1, but the operation of the compressor 21 is controlled by the temperature in the freezer compartment, and the refrigerator compartment is automatically controlled. Even when a damper is provided, the operation and effect of controlling the rotational speed change width of the compressor in two stages or controlling the rotational speed HZ2 of the high-speed compressor 21 to 1.5 times or less the low-speed rotational speed HZ1 are reduced. can get.
[0076]
(Embodiment 6)
FIG. 9 is a configuration diagram of a refrigerator operation control device according to Embodiment 6 of the present invention. Reference numeral 35 denotes a power conversion unit that generates a power supply for varying the capacity of the compressor 21 from a commercial power supply (not shown), and includes a method such as an inverter and a phase control. The power conversion unit 35 includes a power circuit block 36 in which elements (for example, diodes, transistors, etc.) that generate a large amount of heat are integrated, and a power conversion control unit 37 that controls the power circuit block 36 to obtain a predetermined power. . Reference numeral 38 denotes a heat sink for promoting heat radiation of the power circuit block 36.
[0077]
Here, in the case of the rotation speed control by the inverter, the refrigeration capacity, that is, the power consumption of the compressor 21 is minimized by reducing the cylinder capacity of the compressor 21 and optimizing the high-speed rotation speed. By setting the rated power consumption to 60 W or less, the current value flowing through the power circuit block 36 can be suppressed to 1 A or less. As a result, a rise in the temperature of the power circuit block 36 can be suppressed, and the reliability of the power element is significantly improved. Note that the rated power consumption of the electric motor means the power consumption (input) when the compressor is operated continuously at an ambient temperature of 30 ° C. and the refrigerator is cooled to the lowest temperature and stabilized.
[0078]
Further, when a power element of, for example, 3A is conventionally used, the capacity can be reduced to a power element for 1A, and cost can be reduced.
[0079]
Further, the heat sink 38 can be reduced in size or eliminated, so that an inexpensive inverter board can be provided.
[0080]
In the case of a so-called small refrigerator having an internal volume of 200 L or less, the maximum refrigerating capacity of the compressor 21, that is, the maximum power consumption can be easily suppressed because the heat absorption load from the outside air is small. The heat sink 38 can be reduced in size or eliminated more easily.
[0081]
(Embodiment 7)
FIG. 10 is a sectional view of a refrigerator according to Embodiment 7 of the present invention.
[0082]
The vacuum heat insulating material 39 is composed of, for example, a core member made of, for example, a sheet-like inorganic fiber aggregate and a gas barrier film that covers the core member, which is disposed between the inner box and the outer box on the back of the refrigerator box 28. Things.
[0083]
In manufacturing the refrigerator box 28, the vacuum heat insulating material 39 is directly bonded and fixed in advance to, for example, a refrigerator outer box in advance, and then a raw material of hard urethane foam is injected to integrally foam.
[0084]
The vacuum heat insulating material 39 can reduce the heat absorption load of the refrigerator box 28 from the outside air, so that the maximum refrigerating capacity of the compressor 21, that is, the maximum power consumption can be easily suppressed. It is possible to easily reduce the size or abolish the power supply, and provide an inexpensive inverter board.
[0085]
Further, the wall surface temperature of the outer box of the refrigerator on which the vacuum heat insulating material 39 is attached can be raised, so that dew condensation on the outer box of the refrigerator can be prevented.
[0086]
The same effect can be obtained by indirectly bonding the vacuum heat insulating material 39 to the refrigerator outer box.
[0087]
Although the vacuum heat insulating material 39 is arranged on the back surface, if the vacuum heat insulating material 39 is arranged between the inner box on the side of the refrigerator and the heat radiating pipe 22, the heat from the heat radiating pipe 22 during the operation of the compressor 21 to the inside of the refrigerator. Since the amount of heat that can enter can be reduced, the cooling load required to maintain the temperatures in the refrigerator compartment 26 and the freezer compartment 27 is reduced, and the maximum refrigerating capacity of the compressor 21, that is, the maximum power consumption can be suppressed. The downsizing of the power element and the downsizing or elimination of the heat sink 38 can be more easily performed.
[0088]
(Embodiment 8)
Embodiment 8 of the present invention will be described with reference to FIG.
[0089]
As shown in the first embodiment, the compressor 21 is of a variable capacity type in which the control means C1 can change the refrigeration capacity by controlling the refrigerant circulation amount by, for example, controlling the rotation speed by an inverter.
[0090]
The capacity of the compressor 21 can be varied according to the load fluctuation in the refrigerator according to the temperature detected by the refrigerator compartment temperature detecting means TH1. Temperature can be reduced.
[0091]
As a result, the amount of cooling load required to maintain the internal temperature of the refrigerator compartment 26 and the freezer compartment 27 is reduced, and in the case of the rotation speed control by the inverter, the capacity of the cylinder of the compressor 21 is reduced or the rotation speed at the high speed is reduced. By optimizing the number, the refrigeration capacity of the compressor 21 can be minimized.
[0092]
As a result, it is possible to reduce the required amount of refrigerant, and it is possible to improve safety when a flammable refrigerant is used as the refrigerant. Further, in the refrigerator provided with the vacuum heat insulating material as shown in the seventh embodiment, since the amount of heat absorbed by the outside air of the refrigerator box 28 and the heat radiating pipe 22 can be reduced, the compressor 21 of the compressor 21 can be further reduced. Refrigeration capacity can be minimized, the required refrigerant amount can be further reduced, and safety can be improved.
[0093]
【The invention's effect】
As described above, the invention according to claim 1 of the present invention has a refrigerator compartment and a freezer compartment, and the condenser of the refrigerating cycle is constituted only by the heat radiating pipes arranged in the refrigerator box body. In a refrigerator in which the operation of the compressor is controlled by the refrigerator temperature detection means installed in the refrigerator, the capacity of the compressor is variable, and the capacity of the compressor can be changed according to the load fluctuation in the refrigerator, so for example, opening and closing the door During stable operation, the pressure on the high pressure side is reduced by reducing the capacity of the compressor, the temperature of the heat radiating pipe as a condenser can be reduced, and the amount of heat entering the refrigerator can be reduced, thereby conserving energy. In addition, by operating the compressor with a low capacity, the operation time of the compressor can be extended, and the required cooling amount in the freezing room can be secured. In addition, since the operation time of the compressor is extended, the effect of preventing condensation on the outer surface of the refrigerator by the heat radiating pipe is increased.
[0094]
According to a second aspect of the present invention, in the first aspect of the present invention, a heater for heating the refrigerating room is provided in the refrigerating room side urethane or the refrigerating room storage, and electricity is supplied when the compressor is stopped. At low outside air temperature, the freezing room temperature can be ensured, and the compressor can be operated with a low capacity to reduce the compressor stop time, reduce the heater energization rate, and reduce power consumption. .
[0095]
According to a third aspect of the present invention, in the second aspect of the present invention, the energization rate of the heater is controlled by the temperature detected by the outside air temperature detecting means, and the energization of the heater suitable for the ambient temperature is possible. Conventionally, in order to secure the cooling amount of the freezing room at a low outside air temperature in which the operation time of the compressor is particularly short, the aluminum foil heater is set to 100% when the compressor is stopped even at a high outside air temperature when the operation time of the compressor is long. The constant energization and the use of unnecessary heat in the refrigerator compartment caused an increase in power consumption.However, when the outside air temperature increased, the aluminum foil heater was energized with the minimum required energization rate. As a result, waste can be eliminated and the amount of power consumption can be greatly reduced.
[0096]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the rotation speed of the fan is varied according to the temperature detected by the outside air temperature detection means. However, when the fan rotation speed, that is, the air volume is reduced at low outside air temperature, the air volume ratio of the freezer compartment becomes large and the air volume ratio of the refrigerator compartment becomes small, so the cooling volume ratio between the freezer compartment and the refrigerator compartment becomes larger toward the freezer compartment side. In addition, it is easy to secure the cooling amount of the freezing room. In addition, since the cooling amount ratio of the refrigerator compartment is reduced, the stop time of the compressor is shortened, the energization time of the aluminum foil heater can be shortened, and the power consumption can be reduced.
[0097]
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the rotational speed of the variable capacity compressor is controlled in two stages. In the case of, the number of rotations of the compressor can be increased quickly in conjunction with the load in the refrigerator, so that there is an advantage that it can flexibly respond to load fluctuations, but operation with a large compression ratio and low efficiency There was a problem that the power consumption increased due to the increase in time, but the compressor was operated at the high-speed rotation speed only when the load in the refrigerator was extremely increased with two stages of rotation speed change width. By operating at a low rotational speed, the operating time in a state where the compression ratio is small and the efficiency is good can be lengthened, so that the power consumption can be reduced. In addition, since the operation time of the compressor can be extended by setting it to two stages as compared with the multi-stage transmission type in which the capacity of the compressor is quickly increased, it is easy to secure the necessary cooling amount in the freezing room. In addition, compared to the conventional case, the duty ratio of the aluminum foil heater can be reduced, and the power consumption can be reduced.
[0098]
According to a sixth aspect of the present invention, in the invention of the fifth aspect, the ratio of the low-speed side to the high-speed side of the rotational speed of the variable capacity compressor is 1.5 times or less, By minimizing the cooling capacity of the compressor at high speeds, the operating time of the compressor can be extended to the maximum, and it becomes easier to secure the required cooling amount in the freezer compartment. Since the duty ratio of the aluminum foil heater can be reduced, the power consumption can be reduced. In addition, rapid fluctuations in high and low pressure of the compressor may hinder oil supply and may lead to damage to the compressor.However, by minimizing the rotation speed ratio, fluctuations in high and low pressure when the rotation speed changes are reduced. It is possible to reduce the level at which there is no problem in refueling.
[0099]
The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the rated power consumption of the electric motor of the refrigerator is 60 W or less, and the element generating a large amount of heat is By suppressing the current value flowing through the integrated power circuit block to 1 A or less, downsizing of the power element and downsizing or elimination of the heat sink become possible, so that the reliability is remarkably improved and an inexpensive inverter board can be provided.
[0100]
The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the rated internal volume is 200 L or less, for example, 200 L or less for a single person. In the case of a small refrigerator, the heat radiation pipe temperature rises due to the short length of the heat radiation pipe due to the small external surface area, and the influence of the amount of heat entering becomes greater. It is easy to obtain the effect of reducing the amount of heat, whereby the effect of reducing the amount of power consumption can be more remarkably obtained. In addition, since the maximum capacity of the compressor can be suppressed due to the small amount of heat absorption, the rated power consumption of the electric motor of the refrigerator is reduced, and it is possible to reduce the size of the power element, the size of the heat sink, or abolish the heat sink. Can be provided.
[0101]
According to a ninth aspect of the present invention, in the invention according to any one of the first to eighth aspects, the refrigerator box heat insulating portion is provided with a vacuum heat insulating material, and the amount of heat absorbed by the refrigerator is reduced. By further lowering the maximum capacity of the compressor, it is possible to further reduce the rated power consumption of the electric motor of the refrigerator, making it possible to downsize the power element, downsize or eliminate the heat sink, and provide an inexpensive inverter board. it can.
[0102]
According to a tenth aspect of the present invention, there is provided the method according to any one of the first to ninth aspects, wherein a flammable refrigerant is used as the refrigerant. By reducing the amount of heat entering the chiller, the amount of cooling required to secure the temperature of the refrigerator compartment and the freezer compartment can be reduced, so that the amount of charged refrigerant can be reduced, and the safety when flammable refrigerants are used is improved. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a refrigerator according to a first embodiment of the present invention.
FIG. 2 is a sectional view of the refrigerator according to the embodiment.
FIG. 3 is a sectional view of a refrigerator according to a second embodiment of the present invention.
FIG. 4 is a time chart of the refrigerator according to the embodiment;
FIG. 5 is a sectional view of a refrigerator according to a third embodiment of the present invention.
FIG. 6 is a time chart of the refrigerator according to the embodiment;
FIG. 7 is a sectional view of a refrigerator according to a fourth embodiment of the present invention.
FIG. 8 is a time chart showing an operation state of the refrigerator according to the fifth embodiment of the present invention.
FIG. 9 is a configuration diagram of a refrigerator operation control device according to a sixth embodiment of the present invention.
FIG. 10 is a sectional view of a refrigerator according to a seventh embodiment of the present invention.
FIG. 11 is a schematic diagram of a conventional refrigerator.
[Explanation of symbols]
21 Compressor
22 Heat dissipation pipe
25 Cooling fan
26 Refrigerator room
27 Freezer
28 refrigerator box
29 Refrigeration cycle
33 Aluminum foil heater
39 Vacuum insulation
TH1 Refrigerator room temperature detection means
TH2 Outside air temperature detection means

Claims

A refrigerator having a refrigerator compartment and a freezer compartment, in which a condenser of a refrigerating cycle is constituted only by a radiation pipe arranged in a refrigerator box, and controls the operation of the compressor by a refrigerator compartment temperature detecting means installed in the refrigerator compartment. A refrigerator characterized in that the compressor has a variable capacity.

The refrigerator according to claim 1, wherein a heater for heating the refrigerator is provided in the refrigerator-side urethane or the refrigerator compartment, and the heater is energized when the compressor is stopped.

The refrigerator according to claim 2, wherein the duty ratio of the heater is controlled based on the temperature detected by the outside air temperature detecting means.

The refrigerator according to any one of claims 1 to 3, wherein the number of revolutions of the fan is varied according to the temperature detected by the outside air temperature detection means.

In a refrigerator having a refrigerating room and a freezing room, in which a condenser of a refrigerating cycle is constituted only by a heat radiating pipe arranged in a refrigerator box, a compressor of a variable capacity type and a rotational speed of the variable capacity type compressor are controlled. A refrigerator characterized by two-stage control.

6. The refrigerator according to claim 5, wherein the rotation speed ratio between the low speed side and the high speed side of the rotation speed of the variable capacity compressor is 1.5 times or less.

The refrigerator according to any one of claims 1 to 6, wherein a rated power consumption of the electric motor of the refrigerator is set to 60 W or less.

The refrigerator according to any one of claims 1 to 7, wherein the rated internal volume is 200L or less.

The refrigerator according to any one of claims 1 to 8, wherein a vacuum heat insulating material is provided in the refrigerator box heat insulating part.

The refrigerator according to any one of claims 1 to 9, wherein a flammable refrigerant is used as the refrigerant.