JP2004293857A

JP2004293857A - Heat pump device

Info

Publication number: JP2004293857A
Application number: JP2003085034A
Authority: JP
Inventors: Seiichi Yasuki; 誠一安木; Takeji Watanabe; 竹司渡辺; Masahiro Ohama; 昌宏尾浜; Keijiro Kunimoto; 啓次郎國本; Yoshitsugu Nishiyama; 吉継西山; Koji Oka; 浩二岡; Tetsuei Kuramoto; 哲英倉本
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2003-03-26
Filing date: 2003-03-26
Publication date: 2004-10-21

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump device capable of inhibiting the heat radiation in a radiator, and performing the heating operation of a heat absorption unit by sending a high-temperature refrigerant to the heat absorption unit while keeping the differential pressure necessary for the stable operation of a compressor. <P>SOLUTION: A bypass circuit 26 is connected from a discharge side of the compressor 21 to an inlet side of a decompressing means 23, an opening and closing means 28 is mounted on the bypass circuit 26, the radiator 22 is bypassed by opening the opening and closing means 28 in the heating operation of the heat absorption unit, and the refrigerant is allowed to flow into the heat absorption unit 24 through the decompressing means 23, whereby the lowering of a temperature in the radiator 22 of the high-temperature refrigerant can be inhibited, and the heating operation of the heat absorption unit 24 can be performed in a state of keeping the differential pressure between the discharge and suction of the compressor 21 constant or more by reducing the pressure in the decompressing means 23. The heat absorption unit 24 can be efficiently heated, and the compressor 21 can be stably operated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明はヒートポンプによって冷却または加熱を行う、ヒートポンプ装置に関するものである。
【０００２】
【従来の技術】
従来、この種のヒートポンプ装置としては、例えば、吸熱器を加熱する吸熱器加熱運転時に、圧縮機からの冷媒を放熱器から減圧手段を通して吸熱器に流しているものがあった（特許文献１参照）。図５は、特許文献１に記載された従来のヒートポンプ装置を示すものである。
【０００３】
このヒートポンプ装置は図５に示すように、圧縮機１と、給湯熱交換器２と、減圧装置３と、大気熱交換器４とを順に接続してなる冷媒回路５によってヒートポンプサイクルが構成されている。また、貯湯槽６と給湯熱交換器２を水循環回路７で接続し、水循環回路７に設けられた水循環ポンプ８で貯湯槽６に貯留された水を貯湯槽６下部から給湯熱交換器２に循環させて貯湯槽６上部から戻す構成となっている。圧縮機１を運転して冷媒を循環させて、大気熱交換器４に設けたファン９によって大気熱交換器４において大気熱を吸熱し、水循環ポンプ８によって貯湯槽６の底部から供給される水を給湯熱交換器２において加熱して、貯湯槽６の上部に戻していくことで貯湯槽６に湯を貯める貯湯運転を行う。
【０００４】
気温が０〜５℃程度の低温において貯湯運転を行うと、大気熱交換器４での冷媒の温度が低くなり、大気熱交換器４の表面温度が０℃以下になるため、大気中に含まれる水分が大気熱交換器４に霜として付着していく。このまま貯湯運転を続けると霜がさらに付着していき、大気熱交換器４の熱交換効率が悪くなり装置の加熱能力が低下する。よって、このヒートポンプ装置は大気熱交換器４の冷媒温度が低下すると、水循環ポンプ８を停止し、減圧装置３の弁開度を通常運転より大きくして、圧縮機１を運転することによって大気熱交換器４を加熱し、霜を融解させることによって除霜運転を行い、加熱能力の低下を防止する。
【０００５】
また、除霜などのために、大気熱交換器などのヒートポンプサイクルにおける吸熱器を加熱する他の方法としては、圧縮機からの吐出される高温冷媒を直接、吸熱器入口側にバイパスする、ホットガスバイパス方式が知られている。
【０００６】
【特許文献１】
特許第３２９７６５７号公報
【０００７】
【発明が解決しようとする課題】
しかしながら、前記従来の構成では、吸熱器である大気熱交換器を加熱する除霜運転時に、圧縮機から吐出される高温冷媒が放熱器である給湯熱交換器を通るため、給湯熱交換器における放熱によって冷媒の温度が低下し、除霜運転の効率が低下するという課題があった。また、圧縮機から吐出される高温冷媒をバイパスして吸熱器に送る、ホットガスバイパス方式においては直接吸熱器に高温冷媒を送ることができるが、圧縮機と吸熱器のみからなる冷媒回路となるため、圧縮機の吐出側と吸入側の差圧は吸熱器での圧力損失分となる。このとき、圧縮機によっては、例えば、高圧と低圧の差圧によって潤滑油を圧縮機内部に送って圧縮機駆動部の潤滑を行うため、圧縮機駆動部の十分な潤滑を行って運転を行うにはある一定以上の差圧が必要となるものがあり、吸熱器での圧力損失分による差圧だけでは圧縮機の安定した運転に必要な差圧が保てないといった課題があった。
【０００８】
本発明は、前記従来の課題を解決するもので、放熱器における放熱を抑え、かつ、圧縮機の安定した運転に必要な差圧を保って、吸熱器に高温冷媒を送って吸熱器加熱運転を行うことができるヒートポンプ装置を提供することを目的とする。
【０００９】
【課題を解決するための手段】
前記従来の課題を解決するために、圧縮機の吐出側から減圧手段入口側へパイパス回路を接続し、バイパス回路に開閉手段を設けたヒートポンプ装置とする。
【００１０】
これによって、吸熱器加熱運転時に、放熱器をバイパスすることで放熱器における高温冷媒の放熱を抑えるとともに、減圧手段によって減圧することによって圧縮機の吐出と吸入の差圧を一定以上に保って吸熱器の加熱を行うことができる。
【００１１】
【発明の実施の形態】
請求項１に記載の発明は、圧縮機と、放熱器と、減圧手段と、吸熱器とを順に接続してなる冷媒回路において、圧縮機の吐出側から減圧手段入口側へパイパス回路を接続し、バイパス回路に開閉手段を設けている。吸熱器加熱運転時に開閉手段を開けて放熱器をバイパスし、減圧手段を通してから吸熱器に冷媒を流すことで、高温冷媒の放熱器での温度低下を抑えるとともに、減圧手段において減圧することによって圧縮機の吐出と吸入の差圧を一定以上に保って吸熱器の加熱運転を行って、効率よく吸熱器を加熱できるとともに、安定した圧縮機の運転を行うことができる。
【００１２】
請求項２に記載の発明は、特に、請求項１に記載の減圧手段を減圧量可変なものとしたことにより、通常運転時と吸熱器加熱運転時によって減圧量を変化させて、それぞれの運転において最適な減圧量とすることによって、吸熱器加熱運転時において、不必要な減圧によって生じる冷媒の温度低下を抑えて効率よく吸熱器を加熱することができる。
【００１３】
請求項３に記載の発明は、圧縮機と、放熱器と、第１の減圧手段と、吸熱器とを順に接続してなる冷媒回路において、圧縮機の吐出側から吸熱器入口側へバイパスするパイパス回路を接続し、バイパス回路に開閉手段と第２の減圧手段を設けている。吸熱器加熱運転時に開閉手段を開けて放熱器をバイパスし、バイパス回路に設けられた第２の減圧手段を通してから吸熱器に冷媒を流すことで、高温冷媒の放熱器での温度低下を抑えるとともに、吸熱器加熱運転のために設けた第２の減圧手段において減圧することによって、高温冷媒の減圧による温度低下を最小限として圧縮機の吐出と吸入の差圧を一定以上に保って吸熱器の加熱運転を行って、効率よく吸熱器を加熱するとともに、安定した圧縮機の運転を行うことができる。
【００１４】
請求項４に記載の発明は、圧縮機と、放熱器と、第１の減圧手段と、吸熱器とを順に接続してなる冷媒回路において、圧縮機の吐出側から吸熱器入口側へバイパスするパイパス回路を接続し、バイパス回路に開閉手段を設け、冷媒回路におけるバイパス回路出口側接続部から吸熱器の間に第２の減圧手段を設けている。吸熱器加熱運転時に開閉手段を開けて放熱器をバイパスし、第２の減圧手段を通してから吸熱器に冷媒を流すことで、高温冷媒の放熱器での温度低下を抑えるとともに、吸熱器加熱運転のために設けた第２の減圧手段において減圧することによって、高温冷媒の減圧による温度低下を最小限として圧縮機の吐出と吸入の差圧を一定以上に保って吸熱器の加熱運転を行って、効率よく吸熱器を加熱できるとともに、安定した圧縮機の運転を行うことができる。また、通常運転時も第２の減圧手段で減圧を行うことによって、通常運転時に必要な減圧を第２の減圧手段で一部行うことができ、第１の減圧手段での減圧量を小さくすることができる。また、バイパス回路に減圧手段がないため、バイパスされる放熱器側に比べて圧力損失が小さくなるため、吸熱器加熱運転時に、バイパス回路側へほとんどの冷媒を流すことができる。
【００１５】
請求項５に記載の発明は、圧縮機と、放熱器と、第１の減圧手段と、吸熱器とを順に接続してなる冷媒回路において、圧縮機の吐出側から吸熱器入口側へバイパスするパイパス回路を接続し、バイパス回路に開閉手段を設け、冷媒回路における吸熱器出口から圧縮機吸入口の間に減圧量可変である第２の減圧手段を設けている。吸熱器加熱運転時に開閉手段を開けて放熱器をバイパスし、吸熱器に冷媒を流して、第２の減圧手段において減圧を行う。吸熱器に高温冷媒を流してから吸熱器加熱運転のために設けた第２の減圧手段において必要な差圧を保つように減圧することによって、圧縮機から吐出される高温冷媒を吸熱器に直接流すことができ、効率よく吸熱器を加熱できるとともに、圧縮機の吐出と吸入の差圧を一定以上に保って吸熱器の加熱運転を行うことで、安定した圧縮機の運転を行うことができる。また、通常運転時は第２の減圧手段での減圧量を最小にして、通常運転時における吸熱器出口と圧縮機吸入口の間の圧力損失を抑えて通常運転を行うことができる。
【００１６】
請求項６に記載の発明は、特に、請求項１〜６のヒートポンプ装置の冷媒を二酸化炭素としたことによって、二酸化炭素はオゾン破壊係数が０であり、温暖化係数が１と低いため、冷媒回路から冷媒が漏洩した場合でも、環境に与える影響が少ないヒートポンプ装置とすることができる。また、高圧を臨界圧以上となるように運転することで、放熱器において冷媒が凝縮することがなくなる。したがって、放熱器全域で冷媒と非加熱媒体との温度差を形成しやすくなるので、熱交換効率を高くできる。
【００１７】
【実施例】
以下本発明の実施例について、図面を参照しながら説明する。
【００１８】
（実施例１）
図１は本発明の実施例１におけるヒートポンプ装置の構成図である。圧縮機２１と、放熱器である給湯熱交換器２２と、減圧手段である開度を変化させることができる電動膨張弁２３と、吸熱器である大気熱交換器２４を順に接続して作動冷媒に二酸化炭素を用いた冷媒回路２５を構成しており、冷媒回路２５における圧縮機２１の吐出側から電動膨張弁２３の入口側へ接続することで給湯熱交換器２２をバイパスするバイパス回路２６を備え、給湯熱交換器２２とバイパス回路２６の下流側の接続部との間に閉止弁２７を、バイパス回路２６に開閉手段であるバイパス弁２８を備える。また、貯湯槽２９の底部から取出した水を給湯熱交換器２２に流してから貯湯槽２９の上部に戻すように水循環回路３０によって接続され、給湯熱交換器２２の上流側に設けられた水循環ポンプ３１によって送られる貯湯槽２９の底部からの水と冷媒回路２５を流れる冷媒が給湯熱交換器２２において熱交換可能となっている。また、大気熱交換器２４にはファンが設けられ、ファンによって空気を送風することによって冷媒回路を流れる冷媒と空気とが熱交換可能となっている。また、冷媒回路２５における圧縮機２１の吐出側には冷媒吐出温度を検出する吐出温度センサ３３が設けられ、大気熱交換器２４の出口側には大気熱交換器２４の出口冷媒温度を検出する大気熱交換器温度センサ３４が設けられている。そして、制御手段（図示しない）によってこのヒートポンプ装置の各部品の動作を制御可能に構成されている。
【００１９】
以上のように構成されたヒートポンプ装置において、以下にその動作、作用を説明する。図５の従来例と同様に、圧縮機２１を運転し、冷媒回路２５に冷媒を循環させて、大気熱交換器２４において大気の熱を吸熱して、給湯熱交換器２２において貯湯槽２９の底部からの水を加熱して貯湯槽２９の上部に戻すことによって、貯湯槽２９に湯を貯める貯湯運転を行う。このとき冷媒に二酸化炭素を用いているので超臨界サイクルを形成し、給湯熱交換器２２での冷媒は超臨界状態となり、温度変化に凝縮を伴わないため、加熱される水との温度差を大きくとることができるため、加熱後の水の温度を効率よく高温にすることができる。貯湯運転において、外気温が０〜５℃程度で、大気熱交換器２４の表面温度が０℃以下になると大気中の水分が大気熱交換器２４の表面に霜として付着する。霜が付着すると熱交換の効率が低下するため、大気熱交換器２４における冷媒温度が低下していく。そして、さらに大気熱交換器２４への霜の付着が進行することによって大気熱交換器２４での吸熱効率が低下していき、十分な加熱能力が得られなくなる。そのため、大気熱交換器温度センサ３４で検出される大気熱交換器２４出口の冷媒温度が一定の温度以下になると、制御装置によって運転を切替えて除霜運転を行う。ファン３２を停止させて、バイパス弁２８を開き、閉止弁２７を閉じて圧縮機２１を運転することで、大気熱交換器２４の温度を上昇させて付着した霜を溶かす。このとき、閉止弁２７を閉じて給湯熱交換器２２への冷媒の流れを遮断し、バイパス弁２８を開いて、給湯熱交換器２２をバイパスして冷媒を流すので、圧縮機２１から吐出された高温冷媒の給湯熱交換器２２での温度低下を防止することができる。また、電動膨張弁２３を通して減圧することによって差圧を保った除霜運転を行う。このとき、弁開度が調節可能な電動膨張弁２３を用いているため、弁開度を通常の貯湯運転時より開度を大きくして圧縮機２１に必要な差圧を最低限保ちつつ、電動膨張弁２３での減圧による温度低下を抑えることができる。また、除霜運転中も吐出温度センサ３３によって検出される圧縮機２１からの冷媒吐出温度を一定以上の温度に保つように電動膨張弁２３の開度を調節することによって、大量の液冷媒が圧縮機に戻ることを防止することができる。よって、除霜運転時に、効率よく大気熱交換器２４を加熱できるとともに、除霜運転時の状況変化に対応した安定した圧縮機の運転を行うことができる。そして、大気熱交換器温度センサ３４の温度が一定以上になると大気熱交換器２４が十分に加熱されたと判断して制御装置によって貯湯運転に切替える。また、冷媒にオゾン破壊係数が０で温暖化係数が１である二酸化炭素を用いているので、装置の破損などにより冷媒が大気に漏洩しても環境に与える影響はきわめて小さいヒートポンプ装置とすることができる。
【００２０】
なお、給湯熱交換器２２とバイパス回路２６の下流側の接続部との間の閉止弁２７によって除霜運転時に給湯熱交換器２２への冷媒の流れを遮断しているが、この閉止弁２７が設けられていなくても給湯熱交換器２２側に比べてバイパス回路２６側の圧力損失が十分に小さければ、バイパス弁を開けることで圧縮機２１から吐出された高温冷媒の大部分はバイパス回路を流れるので、給湯熱交換器２２における冷媒の温度低下を抑えることができる。また、発明の効果が得られるための放熱器、吸熱器としての熱交換器の構成は図１に示したものに限ったものではなく、ヒートポンプサイクルにおける吸熱器を加熱する運転モードを持つものであればよい。また、冷媒を二酸化炭素としたが、もちろん他の冷媒であってもかまわない。
【００２１】
（実施例２）
図２は本発明の実施例２におけるヒートポンプ装置の構成図である。圧縮機２１と、放熱器である室内温風機２２と、第１の減圧手段である閉止可能な電動膨張弁３５と、吸熱器である大気熱交換器２４を順に接続してなる冷媒回路２５を構成しており、冷媒回路２５における圧縮機２１の吐出側から大気熱交換器２４の入口側へ接続することで室内温風機２２をバイパスするバイパス回路２６を備え、バイパス回路２６に開閉手段であるバイパス弁２８と第２の減圧手段であるキャピラリーチューブ３６を備える。室内温風機２２では暖房のために室内の空気を加熱できるようになっている。大気熱交換器２４にはファンが設けられ、ファンによって空気を送風することによって冷媒回路を流れる冷媒と空気とが熱交換可能となっている。また、大気熱交換器２４の出口冷媒温度を検出する大気熱交換器温度センサ３４が設けられている。そして、制御手段（図示しない）によってこのヒートポンプ装置の各部品の動作を制御可能に構成されている。
【００２２】
以上のように構成されたヒートポンプ装置において、以下にその動作、作用を説明する。圧縮機２１を運転し、冷媒回路２５に冷媒を循環させて、大気熱交換器２４において大気の熱を吸熱して、室内温風機２２において室内の空気を加熱して温風として送風することで暖房を行う。外気温が０〜５℃程度で、大気熱交換器２４の表面温度が０℃以下になる場合においては、貯湯運転中に大気中の水分が大気熱交換器２４の表面に霜として付着する。霜が付着すると熱交換の効率が低下するため、大気熱交換器２４における冷媒温度が低下していく。そして、さらに大気熱交換器２４への霜の付着が進行することによって大気熱交換器２４での吸熱効率が低下していき、十分な加熱能力が得られなくなる。そのため、大気熱交換器温度センサ３４で検出される大気熱交換器２４出口の冷媒温度が一定の温度以下になると、制御装置によって運転を切替えて除霜運転を行う。ファン３２を停止させて、バイパス弁２８を開き、閉止可能である電動膨張弁３５を閉止して圧縮機２１を運転することで、大気熱交換器２４の温度を上昇させて付着した霜を溶かす。このとき、電動膨張弁３５を全閉にして給湯熱交換器２２への冷媒の流れを遮断し、バイパス弁２８を開いて、給湯熱交換器２２をバイパスして冷媒を流すので、圧縮機２１から吐出された高温冷媒の給湯熱交換器２２での温度低下を防止することができ、キャピラリーチューブ３６を通して減圧することによって圧縮機２１に必要な差圧を最低限保って運転することができる。よって、除霜運転時に、効率よく大気熱交換器２４を加熱できるとともに、安定した圧縮機の運転を行うことができる。そして、大気熱交換器温度センサ３４の温度が一定以上になると大気熱交換器２４が十分に加熱されたと判断して制御装置によって貯湯運転に切替える。
【００２３】
なお、電動膨張弁３５を閉止することによって除霜運転時に室内温風機２２への冷媒の流れを遮断することができるが、電動膨張弁３５とは別に閉止弁を設けてもかまわない。また、閉止することができなくても室内温風機２２側に比べてバイパス回路２６側の圧力損失が十分に小さければ、バイパス弁を開けることで圧縮機２１から吐出された高温冷媒の大部分はバイパス回路を流れるので、室内温風機２２における冷媒の温度低下を抑えることができる。また、バイパス回路２６において、バイパス弁２８とキャピラリーチューブ３６の代わりに閉止可能である電動膨張弁を用いることで、バイパス弁２８の閉止機能とキャピラリーチューブ３６の減圧機能を兼ねる構成とすることも可能である。また、発明の効果が得られるための放熱器、吸熱器としての熱交換器の構成は、図２に示したものに限ったものではなく、ヒートポンプサイクルにおける吸熱器を加熱する運転モードを持つものであればよい。
【００２４】
（実施例３）
図３は本発明の実施例３におけるヒートポンプ装置の構成図である。圧縮機２１と、放熱器２２と、第１の減圧手段である第１キャピラリーチューブ３５と、第２の減圧手段である第２キャピラリーチューブ３６と、吸熱器である製氷熱交換器２４を順に接続してなる冷媒回路２５を構成しており、冷媒回路２５における圧縮機２１の吐出側から第１キャピラリーチューブ３５と第２キャピラリーチューブ３６の間に接続することで放熱器２２をバイパスするバイパス回路２６を備え、バイパス回路２６に開閉手段であるバイパス弁２８を備える。また、蓄冷槽３７が設けられており、その下部に水が蓄えられ、上部の空間に製氷熱交換器２４が設置されている。蓄冷槽３７の底部と上部が水循環回路３０によって接続され、水循環回路３０に設けられた水循環ポンプ３１によって、蓄冷槽３７底部の水を蓄冷槽３７上部に送って、製氷熱交換器２４の表面に散布するようになっている。また、製氷熱交換器２４の出口冷媒温度を検出する製氷熱交換器温度センサ３４が設けられている。放熱器２２にはファン３２が設けられ、ファン３２によって空気を送風して冷媒回路を流れる冷媒と空気が熱交換できるようになっている。そして、制御手段（図示しない）によってこのヒートポンプ装置の各部品の動作を制御可能に構成されている。
【００２５】
以上のように構成されたヒートポンプ装置において、以下にその動作、作用を説明する。圧縮機２１を運転し、冷媒回路２５に冷媒を循環させて、製氷熱交換器２４の表面に散布された水を冷却して製氷すると同時に、放熱器２２で冷媒の熱を大気に放熱して製氷運転を行う。製氷運転を行うことによって製氷熱交換器２４の表面に氷が成長していくが、氷の層が厚くなると熱交換の効率が低下するため製氷熱交換器２４における冷媒温度が低下する。そして、さらに大気熱交換器２４への氷の層が成長するにつれて製氷熱交換器２４での冷却効率が低下していく。そのため、製氷熱交換器温度センサ３４で検出される製氷熱交換器２４出口の冷媒温度が一定の温度以下になると、制御装置によって運転を切替えて脱氷運転を行う。バイパス弁２８を開き、圧縮機２１を運転することで、製氷熱交換器２４の温度を上昇させて製氷熱交換器２４表面に成長した氷を溶かして蓄冷槽３７下部へ落下させる。脱氷運転において、バイパス弁２８を開いて、放熱器２２をバイパスして冷媒を流すので、圧縮機２１から吐出された高温冷媒の放熱器２２での温度低下を抑えることができ、第２キャピラリーチューブ３６を通して減圧することによって圧縮機２１に必要な差圧を最低限保って運転することができる。よって、脱氷運転時に、効率よく大気熱交換器２４を加熱できるとともに、安定した圧縮機の運転を行うことができる。また、製氷運転時の減圧は第１キャピラリーチューブ３５と第２キャピラリーチューブ３６の２つのキャピラリーチューブによって行われ、脱氷運転時の減圧は第２キャピラリーチューブ３６によって行われるので、製氷運転、脱氷運転それぞれに適した減圧が行うことができる。また、バイパスされる放熱器２２側は放熱器２２と第１キャピラリーチューブ３５により圧力損失を生じるが、バイパス回路２６にはバイパス弁２８しかないため圧力損失がきわめて小さく、バイパスされる放熱器２２側との圧力損失の差が大きいため、脱氷運転時においてバイパス回路２６側へ冷媒の大部分を流すことができ、放熱器２２側へほとんど冷媒が流れない。そして、製氷運転と脱氷運転を繰り返すことによって氷を蓄冷槽３７下部へ次々と落下させて蓄冷槽３７の水を氷に変えていくことにより蓄冷を行う。
【００２６】
なお、バイパス回路２６によってバイパスされる放熱器２２側に閉止弁を設けることによって完全に圧縮機２１から吐出された高温冷媒をすべてバイパス回路２６によってバイパスする構成とすることも可能である。
【００２７】
また、発明の効果が得られるための放熱器、吸熱器としての熱交換器の構成は、図３に示したものに限ったものではなく、ヒートポンプサイクルにおける吸熱器を加熱する運転モードを持つものであればよい。
【００２８】
（実施例４）
図４は本発明の実施例４におけるヒートポンプ装置の構成図である。基本的な構成は図１に示す実施例１と同じであり、基本的に同一符号は同一部材を示し、同一機能を有しているので、詳細な説明は省略し、異なる点を中心に説明する。
【００２９】
構成において図１と異なるのは、閉止可能な電動膨張弁３５を第１の減圧手段として給湯熱交換器２２と大気熱交換器２４の間に設け、圧縮機２１の吐出側から大気熱交換器２４の入口側へバイパスするバイパス回路２６を備え、閉止弁２７を冷媒回路２５における大気熱交換器２４と圧縮機２１の間に設け、閉止弁２７をと並列に第２の減圧手段としてキャピラリーチューブ３６を設けた点である。
【００３０】
以上のように構成されたヒートポンプ給湯装置において、以下にその動作、作用について図１と異なる点を説明する。本実施例では、ファン３２を停止させて、バイパス弁２８を開き、閉止弁２７を閉止し、電動膨張弁３５を全閉にして圧縮機２１を運転することで、大気熱交換器２４の温度を上昇させて付着した霜を溶かす除霜運転を行う。このとき、電動膨張弁３５を全閉にして給湯熱交換器２２への冷媒の流れを遮断し、バイパス弁２８を開いて、給湯熱交換器２２をバイパスして冷媒を流すので、圧縮機２１から吐出された高温冷媒の給湯熱交換器２２での温度低下を防止することができ、そして、大気熱交換器２４を流したあとの冷媒をキャピラリーチューブ３６によって減圧することによって、圧縮機２１に必要な差圧を最低限保って運転することができるとともに、圧縮機２１からの高温冷媒を減圧によって温度を低下させることなく大気熱交換器２４に流すことができる。よって、除霜運転時に、圧縮機２１からの高温冷媒の温度低下を抑えて大気熱交換器２４を効率よく加熱できるとともに、差圧を保って安定した圧縮機の運転を行うことができる。貯湯運転時には閉止弁２７を開けて閉止弁２７側とキャピラリーチューブ３６側の両方に冷媒を流すことで、この部分で圧力が損失しないようにする。閉止弁２７を開閉することによって貯湯運転と除霜運転に必要な圧力損失にすばやく切替えることができる減圧手段とすることができる。
【００３１】
なお、電動膨張弁３５を閉止することによって除霜運転時に給湯熱交換器２２への冷媒の流れを遮断することができるが、電動膨張弁３５とは別に閉止弁を設けてもかまわない。また、閉止することができなくても室内温風機２２側に比べてバイパス回路２６側の圧力損失が十分に小さければ、バイパス弁を開けることで圧縮機２１から吐出された高温冷媒の大部分はバイパス回路を流れるので、室内温風機２２における冷媒の温度低下を抑えることができる。また、閉止弁２７とキャピラリーチューブ３６によって構成されている部分を開度が変更可能である電動膨張弁とすることで、貯湯運転と除霜運転において減圧量を変化させることも可能であり、貯湯運転では減圧量が少なく、除草運転時には必要な減圧が行えるものであればよい。また、発明の効果が得られるための放熱器、吸熱器としての熱交換器の構成は、図４に示したものに限ったものではなく、ヒートポンプサイクルにおける吸熱器を加熱する運転モードを持つものであればよい。
【００３２】
【発明の効果】
以上のように、本発明によれば、吸熱器加熱運転時に、放熱器をバイパスすることで放熱器における冷媒の放熱を抑えるとともに、減圧手段によって減圧することによって圧縮機の吐出と吸入の差圧を一定以上に保って安定した圧縮機の運転を行うことができる。
【図面の簡単な説明】
【図１】本発明の実施例１におけるヒートポンプ装置の構成図
【図２】本発明の実施例２におけるヒートポンプ装置の構成図
【図３】本発明の実施例３におけるヒートポンプ装置の構成図
【図４】本発明の実施例４におけるヒートポンプ装置の構成図
【図５】従来のヒートポンプ給湯装置の構成図
【符号の説明】
２１圧縮機
２２放熱器
２３減圧手段
２４吸熱器
２５冷媒回路
２６バイパス回路
２８開閉手段
３５第１の減圧手段
３６第２の減圧手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat pump device that performs cooling or heating using a heat pump.
[0002]
[Prior art]
Conventionally, as this type of heat pump device, for example, there has been a heat pump device in which a refrigerant from a compressor flows from a radiator to a heat absorber through a pressure reducing means during a heat absorber heating operation for heating the heat absorber (see Patent Document 1). ). FIG. 5 shows a conventional heat pump device described in Patent Document 1.
[0003]
As shown in FIG. 5, in this heat pump device, a heat pump cycle is configured by a refrigerant circuit 5 that connects a compressor 1, a hot water supply heat exchanger 2, a pressure reducing device 3, and an atmospheric heat exchanger 4 in this order. I have. Further, the hot water storage tank 6 and the hot water supply heat exchanger 2 are connected by a water circulation circuit 7, and the water stored in the hot water storage tank 6 by the water circulation pump 8 provided in the water circulation circuit 7 is transferred from the lower part of the hot water storage tank 6 to the hot water supply heat exchanger 2. It is configured to circulate and return from the upper part of the hot water storage tank 6. The compressor 1 is operated to circulate the refrigerant, absorb the atmospheric heat in the atmospheric heat exchanger 4 by the fan 9 provided in the atmospheric heat exchanger 4, and supply the water supplied from the bottom of the hot water storage tank 6 by the water circulation pump 8. Is heated in the hot water supply heat exchanger 2 and returned to the upper part of the hot water storage tank 6 to perform hot water storage operation for storing hot water in the hot water storage tank 6.
[0004]
When the hot water storage operation is performed at a low temperature of about 0 to 5 ° C., the temperature of the refrigerant in the atmospheric heat exchanger 4 becomes low, and the surface temperature of the atmospheric heat exchanger 4 becomes 0 ° C. or less. The water content adheres to the atmospheric heat exchanger 4 as frost. If the hot-water storage operation is continued as it is, frost will further adhere, the heat exchange efficiency of the atmospheric heat exchanger 4 will deteriorate, and the heating capacity of the device will decrease. Therefore, when the refrigerant temperature of the atmospheric heat exchanger 4 decreases, the heat pump device stops the water circulation pump 8, increases the valve opening of the pressure reducing device 3 from the normal operation, and operates the compressor 1 to operate the atmospheric heat exchanger. The defrosting operation is performed by heating the exchanger 4 and melting the frost, thereby preventing a decrease in the heating capacity.
[0005]
Another method of heating a heat absorber in a heat pump cycle such as an atmospheric heat exchanger for defrosting or the like is to directly bypass a high-temperature refrigerant discharged from a compressor to a heat absorber inlet side. A gas bypass system is known.
[0006]
[Patent Document 1]
Japanese Patent No. 3297657
[0007]
[Problems to be solved by the invention]
However, in the conventional configuration, during the defrosting operation of heating the atmospheric heat exchanger that is the heat absorber, the high-temperature refrigerant discharged from the compressor passes through the hot water supply heat exchanger that is the radiator. There has been a problem that the temperature of the refrigerant decreases due to the heat release, and the efficiency of the defrosting operation decreases. In the hot gas bypass method, high-temperature refrigerant can be directly sent to the heat absorber, while the high-temperature refrigerant discharged from the compressor is sent to the heat absorber by bypassing the refrigerant circuit. Therefore, the differential pressure between the discharge side and the suction side of the compressor is equal to the pressure loss in the heat absorber. At this time, depending on the compressor, for example, lubricating oil is sent to the inside of the compressor by a differential pressure between high pressure and low pressure to lubricate the compressor drive unit, so that the compressor drive unit is operated with sufficient lubrication. Some of them require a differential pressure of a certain level or more, and there is a problem that the differential pressure required for stable operation of the compressor cannot be maintained only by the differential pressure due to the pressure loss in the heat absorber.
[0008]
SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and suppresses heat radiation in a radiator, and maintains a differential pressure necessary for stable operation of a compressor, and sends a high-temperature refrigerant to a heat absorber to perform a heat absorber heating operation. It is an object of the present invention to provide a heat pump device capable of performing the following.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned conventional problem, a heat pump device is provided in which a bypass circuit is connected from a discharge side of a compressor to an inlet side of a pressure reducing means, and an opening / closing means is provided in a bypass circuit.
[0010]
In this way, during the heat absorber heating operation, the heat radiation of the high temperature refrigerant in the heat radiator is suppressed by bypassing the heat radiator, and the pressure difference is reduced by the pressure reducing means to maintain the pressure difference between the discharge and the suction of the compressor at a certain level or more. The vessel can be heated.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
In a refrigerant circuit comprising a compressor, a radiator, a pressure reducing means, and a heat sink connected in order, a bypass circuit is connected from a discharge side of the compressor to an inlet side of the pressure reducing means. , A switching circuit is provided in the bypass circuit. During the heat absorber heating operation, the opening / closing means is opened to bypass the radiator, and the refrigerant flows through the heat absorber after passing through the pressure reducing means, thereby suppressing the temperature decrease of the high-temperature refrigerant in the heat radiator and compressing by reducing the pressure in the pressure reducing means. By performing the heating operation of the heat absorber while maintaining the differential pressure between the discharge and suction of the machine at a certain level or more, the heat absorber can be efficiently heated and the compressor can be operated stably.
[0012]
According to the second aspect of the present invention, in particular, the pressure reducing means according to the first aspect is variable in the amount of reduced pressure, so that the amount of reduced pressure is changed depending on the normal operation and the heat absorber heating operation. By setting the optimum pressure reduction amount in the above, the heat sink can be efficiently heated by suppressing the temperature decrease of the refrigerant caused by unnecessary pressure reduction during the heat absorber heating operation.
[0013]
According to a third aspect of the present invention, in a refrigerant circuit in which a compressor, a radiator, a first decompression unit, and a heat absorber are connected in order, the refrigerant circuit bypasses from a discharge side to a heat absorber inlet side. A bypass circuit is connected, and an opening / closing unit and a second pressure reducing unit are provided in the bypass circuit. During the heat sink heating operation, the opening / closing means is opened to bypass the radiator, and the refrigerant flows to the heat sink through the second pressure reducing means provided in the bypass circuit, thereby suppressing the temperature decrease of the high-temperature refrigerant in the heat radiator. By reducing the pressure in the second pressure reducing means provided for the heat absorber heating operation, the temperature drop due to the reduced pressure of the high-temperature refrigerant is minimized, and the differential pressure between the discharge and suction of the compressor is maintained at a certain level or more. By performing the heating operation, the heat absorber can be efficiently heated, and the compressor can be operated stably.
[0014]
According to a fourth aspect of the present invention, in a refrigerant circuit in which a compressor, a radiator, a first decompression unit, and a heat absorber are connected in order, a bypass is provided from a discharge side of the compressor to a heat absorber inlet side. A bypass circuit is connected to the bypass circuit, and an opening / closing means is provided in the bypass circuit, and a second pressure reducing means is provided between the bypass circuit outlet side connection portion and the heat absorber in the refrigerant circuit. During the heat absorber heating operation, the opening / closing means is opened to bypass the radiator and the refrigerant flows to the heat absorber after passing through the second pressure reducing means, so that the temperature of the high-temperature refrigerant at the heat radiator is suppressed, and the heat absorber heating operation is suppressed. By reducing the pressure in the second pressure reducing means provided for, the temperature decrease due to the reduced pressure of the high-temperature refrigerant is minimized, and the heating operation of the heat absorber is performed while maintaining the differential pressure between the discharge and suction of the compressor at a certain level or more, The heat absorber can be efficiently heated, and the compressor can be operated stably. In addition, by reducing the pressure by the second pressure reducing means also during the normal operation, the required pressure reduction during the normal operation can be partially performed by the second pressure reducing means, and the amount of reduced pressure by the first pressure reducing means is reduced. be able to. Further, since there is no pressure reducing means in the bypass circuit, the pressure loss is smaller than that of the radiator to be bypassed, so that most of the refrigerant can flow to the bypass circuit during the heat absorber heating operation.
[0015]
According to a fifth aspect of the present invention, in a refrigerant circuit in which a compressor, a radiator, a first decompression unit, and a heat absorber are sequentially connected, a bypass is provided from a discharge side of the compressor to a heat absorber inlet side. A bypass circuit is connected to the bypass circuit, and an opening / closing means is provided in the bypass circuit, and a second pressure reducing means that is variable in pressure reduction amount is provided between an outlet of the heat absorber and a suction port of the compressor in the refrigerant circuit. At the time of the heat absorber heating operation, the opening / closing means is opened to bypass the radiator, the refrigerant is caused to flow through the heat absorber, and the pressure is reduced by the second pressure reducing means. The high-temperature refrigerant discharged from the compressor is directly supplied to the heat absorber by flowing the high-temperature refrigerant through the heat absorber and then reducing the pressure to maintain the necessary differential pressure in the second pressure reducing means provided for the heat absorber heating operation. It is possible to heat the heat absorber efficiently, and to heat the heat absorber while maintaining the differential pressure between the discharge and suction of the compressor at a certain level or more, thereby performing a stable operation of the compressor. . Further, during normal operation, the amount of pressure reduction by the second pressure reducing means can be minimized, and normal operation can be performed while suppressing the pressure loss between the heat absorber outlet and the compressor suction port during normal operation.
[0016]
The invention according to claim 6 is particularly characterized in that carbon dioxide is used as the refrigerant of the heat pump device according to claims 1 to 6, and the carbon dioxide has a low ozone depletion potential of 0 and a low global warming potential of 1; Even if the refrigerant leaks from the circuit, it is possible to provide a heat pump device that has little effect on the environment. In addition, by operating the high pressure to be equal to or higher than the critical pressure, the refrigerant does not condense in the radiator. Therefore, a temperature difference between the refrigerant and the non-heating medium can be easily formed in the entire radiator, so that the heat exchange efficiency can be increased.
[0017]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
(Example 1)
FIG. 1 is a configuration diagram of the heat pump device according to the first embodiment of the present invention. A working refrigerant is connected to a compressor 21, a hot water supply heat exchanger 22 as a radiator, an electric expansion valve 23 as a decompression means capable of changing an opening degree, and an atmospheric heat exchanger 24 as a heat absorber in order. And a bypass circuit 26 that bypasses the hot water supply heat exchanger 22 by connecting the refrigerant circuit 25 from the discharge side of the compressor 21 to the inlet side of the electric expansion valve 23 in the refrigerant circuit 25. A shutoff valve 27 is provided between the hot water supply heat exchanger 22 and a connection portion on the downstream side of the bypass circuit 26, and a bypass valve 28 serving as an opening / closing means is provided in the bypass circuit 26. A water circulation circuit 30 is connected by a water circulation circuit 30 so that water taken out from the bottom of the hot water storage tank 29 flows to the hot water supply heat exchanger 22 and then returns to the upper part of the hot water storage tank 29, and is provided on the upstream side of the hot water supply heat exchanger 22. Water from the bottom of the hot water storage tank 29 sent by the pump 31 and the refrigerant flowing through the refrigerant circuit 25 can exchange heat in the hot water supply heat exchanger 22. Further, a fan is provided in the atmospheric heat exchanger 24, and air can be exchanged between the refrigerant flowing through the refrigerant circuit and the air by blowing the air with the fan. Further, a discharge temperature sensor 33 for detecting a refrigerant discharge temperature is provided on the discharge side of the compressor 21 in the refrigerant circuit 25, and an outlet refrigerant temperature of the atmospheric heat exchanger 24 is detected on an outlet side of the atmospheric heat exchanger 24. An atmospheric heat exchanger temperature sensor 34 is provided. The operation of each component of the heat pump device can be controlled by control means (not shown).
[0019]
The operation and operation of the heat pump device configured as described above will be described below. As in the conventional example of FIG. 5, the compressor 21 is operated, the refrigerant is circulated through the refrigerant circuit 25, the atmospheric heat is absorbed by the atmospheric heat exchanger 24, and the hot water is stored in the hot water storage tank 29 by the hot water supply heat exchanger 22. By heating the water from the bottom and returning it to the top of the hot water storage tank 29, a hot water storage operation for storing hot water in the hot water storage tank 29 is performed. At this time, since carbon dioxide is used as the refrigerant, a supercritical cycle is formed, and the refrigerant in the hot water supply heat exchanger 22 is in a supercritical state, and the temperature change does not accompany condensation, so that the temperature difference with the heated water is reduced. Since the temperature can be increased, the temperature of the heated water can be efficiently increased. In the hot water storage operation, when the outside air temperature is about 0 to 5 ° C. and the surface temperature of the atmospheric heat exchanger 24 becomes 0 ° C. or less, moisture in the atmosphere adheres to the surface of the atmospheric heat exchanger 24 as frost. When the frost adheres, the efficiency of heat exchange decreases, so that the refrigerant temperature in the atmospheric heat exchanger 24 decreases. Then, as the adhesion of frost to the atmospheric heat exchanger 24 further progresses, the heat absorption efficiency in the atmospheric heat exchanger 24 decreases, and a sufficient heating capacity cannot be obtained. Therefore, when the refrigerant temperature at the outlet of the atmospheric heat exchanger 24 detected by the atmospheric heat exchanger temperature sensor 34 falls below a certain temperature, the operation is switched by the control device to perform the defrosting operation. The fan 32 is stopped, the bypass valve 28 is opened, the shut-off valve 27 is closed, and the compressor 21 is operated to raise the temperature of the atmospheric heat exchanger 24 and melt the attached frost. At this time, the closing valve 27 is closed to shut off the flow of the refrigerant to the hot water supply heat exchanger 22, and the bypass valve 28 is opened to flow the refrigerant by bypassing the hot water supply heat exchanger 22, so that the refrigerant is discharged from the compressor 21. It is possible to prevent the high-temperature refrigerant from lowering in the hot water supply heat exchanger 22. In addition, a defrosting operation is performed in which the pressure difference is maintained by reducing the pressure through the electric expansion valve 23. At this time, since the electric expansion valve 23 whose valve opening can be adjusted is used, the valve opening is made larger than that during the normal hot water storage operation, and the differential pressure necessary for the compressor 21 is kept to a minimum. It is possible to suppress a temperature decrease due to the pressure reduction in the electric expansion valve 23. Also, during the defrosting operation, by adjusting the opening of the electric expansion valve 23 so that the refrigerant discharge temperature from the compressor 21 detected by the discharge temperature sensor 33 is maintained at a certain temperature or higher, a large amount of liquid refrigerant can be discharged. Return to the compressor can be prevented. Therefore, at the time of the defrosting operation, the atmospheric heat exchanger 24 can be efficiently heated, and the stable operation of the compressor corresponding to the change of the situation at the time of the defrosting operation can be performed. When the temperature of the atmospheric heat exchanger temperature sensor 34 becomes equal to or higher than a predetermined value, it is determined that the atmospheric heat exchanger 24 has been sufficiently heated, and the controller switches to the hot water storage operation. In addition, since carbon dioxide having an ozone depletion potential of 0 and a global warming potential of 1 is used as the refrigerant, the heat pump device should have an extremely small effect on the environment even if the refrigerant leaks to the atmosphere due to damage to the device. Can be.
[0020]
The flow of the refrigerant to the hot water supply heat exchanger 22 during the defrosting operation is shut off by the shutoff valve 27 between the hot water supply heat exchanger 22 and the connection portion on the downstream side of the bypass circuit 26. If the pressure loss on the bypass circuit 26 side is sufficiently smaller than that on the hot water supply heat exchanger 22 side even if the hot water supply heat exchanger 22 is not provided, most of the high-temperature refrigerant discharged from the compressor 21 is opened by opening the bypass valve. , It is possible to suppress a decrease in the temperature of the refrigerant in the hot water supply heat exchanger 22. Further, the configuration of the heat exchanger as the radiator and the heat absorber for obtaining the effect of the invention is not limited to that shown in FIG. 1 but has an operation mode for heating the heat absorber in the heat pump cycle. I just need. In addition, although the refrigerant is carbon dioxide, it is needless to say that another refrigerant may be used.
[0021]
(Example 2)
FIG. 2 is a configuration diagram of a heat pump device according to a second embodiment of the present invention. A refrigerant circuit 25 formed by sequentially connecting a compressor 21, an indoor warm air blower 22 as a radiator, a closable electric expansion valve 35 as a first pressure reducing means, and an atmospheric heat exchanger 24 as a heat absorber is provided. A bypass circuit 26 that connects the discharge side of the compressor 21 in the refrigerant circuit 25 to the inlet side of the atmospheric heat exchanger 24 to bypass the indoor hot air blower 22; The apparatus includes a bypass valve 28 and a capillary tube 36 as a second pressure reducing means. The indoor warm air blower 22 can heat indoor air for heating. The atmospheric heat exchanger 24 is provided with a fan, and air can be exchanged between the refrigerant flowing through the refrigerant circuit and the air by blowing the air with the fan. Further, an atmospheric heat exchanger temperature sensor 34 for detecting the outlet refrigerant temperature of the atmospheric heat exchanger 24 is provided. The operation of each component of the heat pump device can be controlled by control means (not shown).
[0022]
The operation and operation of the heat pump device configured as described above will be described below. By operating the compressor 21, circulating the refrigerant in the refrigerant circuit 25, absorbing the heat of the atmosphere in the atmospheric heat exchanger 24, heating the indoor air in the indoor warm air blower 22, and blowing it as warm air. Perform heating. When the outside air temperature is about 0 to 5 ° C. and the surface temperature of the atmospheric heat exchanger 24 is 0 ° C. or less, moisture in the atmosphere adheres to the surface of the atmospheric heat exchanger 24 as frost during the hot water storage operation. When the frost adheres, the efficiency of heat exchange decreases, so that the refrigerant temperature in the atmospheric heat exchanger 24 decreases. Then, as the adhesion of frost to the atmospheric heat exchanger 24 further progresses, the heat absorption efficiency in the atmospheric heat exchanger 24 decreases, and a sufficient heating capacity cannot be obtained. Therefore, when the refrigerant temperature at the outlet of the atmospheric heat exchanger 24 detected by the atmospheric heat exchanger temperature sensor 34 falls below a certain temperature, the operation is switched by the control device to perform the defrosting operation. The fan 32 is stopped, the bypass valve 28 is opened, the closeable electric expansion valve 35 is closed, and the compressor 21 is operated to raise the temperature of the atmospheric heat exchanger 24 and melt the attached frost. . At this time, the electric expansion valve 35 is fully closed to shut off the flow of the refrigerant to the hot water supply heat exchanger 22, and the bypass valve 28 is opened to bypass the hot water supply heat exchanger 22 and flow the refrigerant. Temperature of the high-temperature refrigerant discharged from the hot water supply heat exchanger 22 can be prevented, and the pressure can be reduced through the capillary tube 36, so that the compressor 21 can be operated while keeping the necessary differential pressure to a minimum. Therefore, during the defrosting operation, the atmospheric heat exchanger 24 can be efficiently heated, and the compressor can be operated stably. When the temperature of the atmospheric heat exchanger temperature sensor 34 becomes equal to or higher than a predetermined value, it is determined that the atmospheric heat exchanger 24 has been sufficiently heated, and the controller switches to the hot water storage operation.
[0023]
In addition, by closing the electric expansion valve 35, the flow of the refrigerant to the indoor hot air blower 22 can be cut off during the defrosting operation. However, a closing valve may be provided separately from the electric expansion valve 35. If the pressure loss on the bypass circuit 26 side is sufficiently smaller than that on the indoor warm air blower 22 side even if it cannot be closed, most of the high temperature refrigerant discharged from the compressor 21 by opening the bypass valve Since the refrigerant flows through the bypass circuit, a decrease in the temperature of the refrigerant in the indoor warm air blower 22 can be suppressed. Further, in the bypass circuit 26, by using a motor-operable expansion valve that can be closed instead of the bypass valve 28 and the capillary tube 36, it is also possible to adopt a configuration that combines the function of closing the bypass valve 28 and the function of reducing the pressure of the capillary tube 36. It is. Further, the configuration of the heat exchanger as the radiator and the heat absorber for obtaining the effect of the invention is not limited to that shown in FIG. 2, but has an operation mode of heating the heat absorber in the heat pump cycle. Should be fine.
[0024]
(Example 3)
FIG. 3 is a configuration diagram of a heat pump device according to Embodiment 3 of the present invention. The compressor 21, the radiator 22, the first capillary tube 35 as the first decompression means, the second capillary tube 36 as the second decompression means, and the ice making heat exchanger 24 as the heat absorber are connected in order. The refrigerant circuit 25 includes a bypass circuit 26 that connects the first capillary tube 35 and the second capillary tube 36 from the discharge side of the compressor 21 in the refrigerant circuit 25 to bypass the radiator 22. And the bypass circuit 26 is provided with a bypass valve 28 as an opening / closing means. Further, a cool storage tank 37 is provided, water is stored in a lower part thereof, and an ice making heat exchanger 24 is installed in an upper space. The bottom and the top of the cool storage tank 37 are connected by a water circulation circuit 30, and the water in the bottom of the cool storage tank 37 is sent to the top of the cool storage tank 37 by a water circulation pump 31 provided in the water circulation circuit 30, and the water is supplied to the surface of the ice making heat exchanger 24. It is designed to be sprayed. Further, an ice making heat exchanger temperature sensor 34 for detecting the outlet refrigerant temperature of the ice making heat exchanger 24 is provided. The radiator 22 is provided with a fan 32, and air can be exchanged with the refrigerant flowing through the refrigerant circuit by blowing air by the fan 32. The operation of each component of the heat pump device can be controlled by control means (not shown).
[0025]
The operation and operation of the heat pump device configured as described above will be described below. The compressor 21 is operated, the refrigerant is circulated through the refrigerant circuit 25, and water sprayed on the surface of the ice making heat exchanger 24 is cooled to make ice. Perform ice making operation. By performing the ice making operation, ice grows on the surface of the ice making heat exchanger 24. However, if the ice layer becomes thicker, the efficiency of heat exchange decreases, and the refrigerant temperature in the ice making heat exchanger 24 decreases. Then, as the ice layer grows on the atmospheric heat exchanger 24, the cooling efficiency in the ice making heat exchanger 24 decreases. Therefore, when the refrigerant temperature at the outlet of the ice making heat exchanger 24 detected by the ice making heat exchanger temperature sensor 34 falls below a certain temperature, the operation is switched by the control device to perform the de-icing operation. By opening the bypass valve 28 and operating the compressor 21, the temperature of the ice making heat exchanger 24 is raised, so that the ice grown on the surface of the ice making heat exchanger 24 is melted and dropped to the lower part of the cold storage tank 37. In the de-icing operation, since the bypass valve 28 is opened and the refrigerant flows by bypassing the radiator 22, the temperature of the high-temperature refrigerant discharged from the compressor 21 in the radiator 22 can be suppressed, and the second capillary can be suppressed. By reducing the pressure through the tube 36, the compressor 21 can be operated while keeping the necessary differential pressure at a minimum. Therefore, during the deicing operation, the atmospheric heat exchanger 24 can be efficiently heated, and the compressor can be operated stably. In addition, the depressurization during the ice making operation is performed by two capillary tubes, the first capillary tube 35 and the second capillary tube 36, and the depressurization during the deicing operation is performed by the second capillary tube 36. Pressure reduction suitable for each operation can be performed. The bypass radiator 22 has a pressure loss due to the radiator 22 and the first capillary tube 35. However, since the bypass circuit 26 has only the bypass valve 28, the pressure loss is extremely small. Since the pressure difference between the refrigerant and the refrigerant is large, most of the refrigerant can flow to the bypass circuit 26 side during the de-icing operation, and almost no refrigerant flows to the radiator 22 side. Then, by repeatedly performing the ice making operation and the de-icing operation, ice is successively dropped to the lower part of the cold storage tank 37, and the cold storage is performed by changing the water in the cold storage tank 37 to ice.
[0026]
By providing a shut-off valve on the side of the radiator 22 that is bypassed by the bypass circuit 26, it is possible to completely bypass the high-temperature refrigerant discharged from the compressor 21 by the bypass circuit 26.
[0027]
Further, the configuration of the heat exchanger as the radiator and the heat absorber for obtaining the effect of the invention is not limited to that shown in FIG. 3, and has an operation mode of heating the heat absorber in the heat pump cycle. Should be fine.
[0028]
(Example 4)
FIG. 4 is a configuration diagram of a heat pump device according to Embodiment 4 of the present invention. The basic configuration is the same as that of the first embodiment shown in FIG. 1. Basically, the same reference numerals denote the same members, and have the same functions. Therefore, detailed description is omitted, and different points are mainly described. I do.
[0029]
The configuration differs from that of FIG. 1 in that a closable electric expansion valve 35 is provided as a first pressure reducing means between the hot water supply heat exchanger 22 and the atmospheric heat exchanger 24, and the atmospheric heat exchanger is discharged from the discharge side of the compressor 21. A bypass circuit 26 for bypassing to the inlet side of the compressor 24, a shut-off valve 27 is provided between the atmospheric heat exchanger 24 and the compressor 21 in the refrigerant circuit 25, and the shut-off valve 27 is arranged in parallel with the capillary tube as a second pressure reducing means. 36 is provided.
[0030]
In the heat pump hot water supply apparatus configured as described above, the operation and operation of the heat pump hot water supply apparatus will be described below focusing on differences from FIG. In the present embodiment, the fan 32 is stopped, the bypass valve 28 is opened, the shutoff valve 27 is closed, the electric expansion valve 35 is fully closed, and the compressor 21 is operated. To perform a defrosting operation to melt the attached frost. At this time, the electric expansion valve 35 is fully closed to shut off the flow of the refrigerant to the hot water supply heat exchanger 22, and the bypass valve 28 is opened to bypass the hot water supply heat exchanger 22 and flow the refrigerant. The temperature of the high-temperature refrigerant discharged from the hot water supply heat exchanger 22 can be prevented from decreasing, and the refrigerant after flowing through the atmospheric heat exchanger 24 is depressurized by the capillary tube 36, so that the compressor 21 The operation can be performed while maintaining the required differential pressure to a minimum, and the high-temperature refrigerant from the compressor 21 can be flown to the atmospheric heat exchanger 24 without lowering the temperature by decompression. Therefore, at the time of the defrosting operation, the temperature of the high-temperature refrigerant from the compressor 21 can be suppressed from being lowered, the atmospheric heat exchanger 24 can be efficiently heated, and the compressor can be stably operated while maintaining the differential pressure. During the hot-water storage operation, the shut-off valve 27 is opened, and the refrigerant flows through both the shut-off valve 27 and the capillary tube 36 so that the pressure is not lost at this portion. By opening and closing the closing valve 27, it is possible to provide a pressure reducing means capable of quickly switching to the pressure loss required for the hot water storage operation and the defrosting operation.
[0031]
In addition, by closing the electric expansion valve 35, the flow of the refrigerant to the hot water supply heat exchanger 22 can be cut off during the defrosting operation, but a closing valve may be provided separately from the electric expansion valve 35. If the pressure loss on the bypass circuit 26 side is sufficiently smaller than that on the indoor warm air blower 22 side even if it cannot be closed, most of the high temperature refrigerant discharged from the compressor 21 by opening the bypass valve Since the refrigerant flows through the bypass circuit, a decrease in the temperature of the refrigerant in the indoor warm air blower 22 can be suppressed. Further, by using a portion constituted by the closing valve 27 and the capillary tube 36 as an electric expansion valve whose opening degree can be changed, it is possible to change the amount of pressure reduction in the hot water storage operation and the defrosting operation. In operation, the amount of pressure reduction is small, and any pressure reduction required for weeding operation can be performed. Further, the configuration of the heat exchanger as a radiator and a heat absorber for obtaining the effects of the invention is not limited to that shown in FIG. 4, and has an operation mode of heating the heat absorber in a heat pump cycle. Should be fine.
[0032]
【The invention's effect】
As described above, according to the present invention, during the heat absorber heating operation, the heat radiation of the refrigerant in the radiator is suppressed by bypassing the radiator, and the pressure difference between the discharge and suction of the compressor is reduced by reducing the pressure by the pressure reducing means. Can be maintained at a certain value or more, and stable operation of the compressor can be performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a heat pump device according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of a heat pump device according to a second embodiment of the present invention.
FIG. 3 is a configuration diagram of a heat pump device according to a third embodiment of the present invention.
FIG. 4 is a configuration diagram of a heat pump device according to a fourth embodiment of the present invention.
FIG. 5 is a configuration diagram of a conventional heat pump water heater.
[Explanation of symbols]
21 Compressor
22 radiator
23 Decompression means
24 heat absorber
25 Refrigerant circuit
26 Bypass circuit
28 Opening / closing means
35 First decompression means
36 Second decompression means

Claims

A compressor, a radiator, a pressure reducing means, and a refrigerant circuit formed by sequentially connecting the heat absorber, a bypass circuit was connected from a discharge side of the compressor to a pressure reducing means inlet side, and an opening / closing means was provided in a bypass circuit. Heat pump device.

2. The heat pump device according to claim 1, wherein the pressure reducing unit is configured to change a reduced pressure amount.

In a refrigerant circuit formed by sequentially connecting a compressor, a radiator, a first decompression unit, and a heat absorber, a bypass circuit that bypasses from a discharge side of the compressor to an inlet side of the heat absorber is connected to the bypass circuit. A heat pump device provided with an opening / closing means and a second pressure reducing means.

In a refrigerant circuit formed by sequentially connecting a compressor, a radiator, a first decompression unit, and a heat absorber, a bypass circuit that bypasses from a discharge side of the compressor to an inlet side of the heat absorber is connected to the bypass circuit. A heat pump device comprising an opening / closing means and a second pressure reducing means provided between a bypass circuit outlet-side connection part in a refrigerant circuit and a heat absorber.

In a refrigerant circuit formed by sequentially connecting a compressor, a radiator, a first decompression unit, and a heat absorber, a bypass circuit that bypasses from a discharge side of the compressor to an inlet side of the heat absorber is connected to the bypass circuit. A heat pump device comprising an opening / closing means, and a second pressure reducing means which is variable in pressure reduction amount between an outlet of a heat absorber and a suction port of a compressor in a refrigerant circuit.

The heat pump device according to any one of claims 1 to 5, wherein the refrigerant is carbon dioxide.