JP3633500B2

JP3633500B2 - Heat pump water heater

Info

Publication number: JP3633500B2
Application number: JP2001089463A
Authority: JP
Inventors: 昌宏尾浜; 竹司渡辺; 松本　　聡
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2001-03-27
Filing date: 2001-03-27
Publication date: 2005-03-30
Anticipated expiration: 2021-03-27
Also published as: JP2002286288A

Description

【０００１】
【発明の属する技術分野】
本発明は貯湯式のヒートポンプ給湯機に関するものである。
【０００２】
【従来の技術】
従来のこの種のヒートポンプ給湯機は特開昭６０−１６４１５７号公報に示すようなものがある。図２０は従来のヒートポンプ給湯機の構成図である。図２０において、圧縮機１、冷媒対水熱交換器２、減圧装置３、蒸発器４からなる冷媒循環回路と、貯湯槽５、循環ポンプ６、前記冷媒対水熱交換器２、補助加熱器７を接続した給湯回路から成り、前記圧縮機１より吐出された高温高圧の過熱ガス冷媒は前記冷媒対水熱交換器２に流入し、ここで前記循環ポンプ６から送られてきた水を加熱し凝縮する。
【０００３】
そして、凝縮液化した冷媒は前記減圧装置３で減圧され、前記蒸発器４に流入し、ここで大気熱を吸熱して蒸発ガス化し、前記圧縮機１に戻る。一方、前記冷媒対水熱交換器２で加熱された湯は前記貯湯槽５の上部に流入し、上から次第に貯湯されていく。そして、前記冷媒対水熱交換器２の入口水温が設定値に達すると、これを給水温度検出手段８が検知して前記圧縮機１によるヒートポンプ運転を停止し、前記補助加熱器７の単独運転に切り換えるものである。
【０００４】
【発明が解決しようとする課題】
しかしながら、上記のような従来例の構成では、沸き上げ運転時間の経過とともに貯湯槽５内の湯と水の接する部分で湯水混合層が生じ、その層は次第に拡大していく。図２１は貯湯槽５内の湯の温度分布を示す。同図中において、T1は沸き上げ温度（高温湯）であり、T2は市水温度（低温湯）である。前述の湯水混合層は、高温湯と低温湯の熱伝導および対流により発生するものであり、高温湯から低温湯へ伝熱されその境界部分で高温湯は温度低下し、逆に低温湯は温度上昇する。
【０００５】
従って、貯湯槽５の沸き上げ完了近くになると、前記冷媒対水熱交換器２に流入する給水温度は高くなるため、前記圧縮機１の吐出圧力は上昇して、モータの巻線温度の上昇など圧縮機１の耐久性が課題となってくる。
【０００６】
図２２は横軸に前記冷媒対水熱交換器２に流入する給水温度を示し、縦軸にその時の圧縮機１の吐出圧力を示して、給水温度に対する圧縮機１の吐出圧力の関係を示したものである。同図中の圧力Ｐは常用上限圧力であり、圧縮機１の耐久性を保証するためには、通常運転ではこの圧力以下で運転する必要がある。圧力Ｐの時の給水温度は同図中よりT3となる。
【０００７】
また、有効な湯温の下限をTu（例えば４５℃）とし、前述のT3とTuを図２１に示す。同図の左側に示す貯湯槽５の断面図において、湯温T3以下の領域は沸き上げ可能な領域であり、Tu以上の領域は有効な湯として使用できる領域である。しかし、湯温T3とTuの間の領域（斜線の部分）は有効な湯として利用できない領域である。
【０００８】
このように従来例の構成では、前記冷媒対水熱交換器２に流れる水温が低い状態で運転を停止せざるをえないので、前記貯湯槽５の下部が低温の水の状態で停止することになり、前記貯湯槽５の湯容量を有効に利用できない。そのため、貯湯熱量は減少し、給湯負荷を満足することができない。これを解決する方法の一つとして、貯湯槽５の容量を大きくすることが考えられる。
【０００９】
しかし、この場合には、貯湯槽５の設置面積が大きくなり、設置の自由度が制限され、かつ、コストが高くなるという課題がある。また、他の方法として、ヒートポンプ運転を停止した後、補助加熱器７の単独運転で貯湯熱量を増加する方法がある。しかし、この場合には、ヒータなどで加熱するため、消費電力が大きくなり、効率が悪くなるという課題がある。
【００１０】
本発明は、上記従来の課題を解決するもので、圧縮機の異常温度上昇ならびに異常圧力上昇もなく、低消費電力量で貯湯槽の下部まで高温湯を貯湯し、湯容量を有効に利用可能としたヒートポンプ給湯機を提供することを目的とする。
【００１１】
【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本発明は、圧縮機、冷媒対水熱交換器、冷媒の流量を制御する減圧装置、蒸発器を有する冷媒循環回路と、貯湯槽、循環ポンプ、前記冷媒対水熱交換器を有する給湯回路と、前記冷媒対水熱交換器の水側出口水温である沸き上げ温度を一定にするために前記循環ポンプの流量を制御する流量制御手段と、前記貯湯槽中の湯水混合層を検出する沸き上げ完了直前検出手段と、前記沸き上げ完了直前検出手段からの信号が所定の信号になった時に前記減圧装置の弁開度を段階的に開くように制御する制御手段とを備え、弁開度が変化しても沸き上げ温度を一定にするヒートポンプ給湯機としたものである。従って、沸き上げ完了に近づき、圧縮機の吐出圧力が上昇する場合に、減圧装置の開度を開くように制御し、吐出圧力を低く押さえるとともに弁開度が変化しても沸き上げ温度を一定にするので、高温の給水温度まで給湯加熱運転が可能となるものである。
【００１２】
【発明の実施の形態】
請求項１に記載の発明は、圧縮機、冷媒対水熱交換器、冷媒の流量を制御する減圧装置、蒸発器を有する冷媒循環回路と、貯湯槽、循環ポンプ、前記冷媒対水熱交換器を有する給湯回路と、前記冷媒対水熱交換器の水側出口水温である沸き上げ温度を一定にするために前記循環ポンプの流量を制御する流量制御手段と、前記貯湯槽中の湯水混合層を検出する沸き上げ完了直前検出手段と、前記沸き上げ完了直前検出手段からの信号が所定の信号になった時に前記減圧装置の弁開度を段階的に開くように制御する制御手段とを備え、弁開度が変化しても沸き上げ温度を一定にするヒートポンプ給湯機とすることにより、沸き上げ完了に近づき、圧縮機の吐出圧力が上昇する場合に、減圧装置の弁開度を開くように制御し、吐出圧力を低く押さえ、高温の給水温度まで給湯加熱運転が可能となり、貯湯槽の湯容量を有効に利用できるものである。
請求項２に記載の発明は、沸き上げ完了直前検出手段が所定温度を検出すると圧縮機を停止する請求項１記載のヒートポンプ給湯機とするものである。
【００１３】
請求項３に記載の発明は、圧縮機、冷媒対水熱交換器、冷媒の流量を制御する減圧装置、蒸発器を有する冷媒循環回路と、貯湯槽、循環ポンプ、前記冷媒対水熱交換器を有する給湯回路と、前記冷媒対水熱交換器の水側出口水温である沸き上げ温度を一定にするために前記循環ポンプの流量を制御する流量制御手段と、前記給湯回路に設けられ前記冷媒対水熱交換器に流入する前の給水の温度を検知する給水温度検出手段とを有し、前記給水温度検出手段からの信号が所定の信号になった時に前記減圧装置の弁開度を段階的に開くように制御する制御手段とを備え、弁開度が変化しても沸き上げ温度を一定にするヒートポンプ給湯機とすることにより、沸き上げ完了に近づき、圧縮機の吐出圧力が上昇する場合に、減圧装置の弁開度を開くように制御し、吐出圧力を低く押さえ、高温の給水温度まで給湯加熱運転が可能となり、貯湯槽の湯容量を有効に利用できるものである。
【００１４】
請求項４に記載の発明は、給水温度検出手段からの信号が所定温度を検出すると圧縮機を停止する請求項３記載のヒートポンプ給湯機とするものである。
【００１５】
請求項５に記載の発明は、減圧装置の弁開度の変更量は外気温度を検出する外気温度検出手段から得た外気温度に応じて決定する制御手段を備えたことにより、外気温度に応じた最適な減圧装置の弁開度の変更を行うので、貯湯槽の湯容量を有効に利用でき、かつ、効率の良い給湯加熱運転ができるものである。
【００１６】
請求項６に記載の発明は、給水温度が高いほど減圧装置の弁開度の変更量を大きくした制御手段を備えたことにより、吐出圧力の上昇が大きい高給水温度時に減圧装置の弁開度の変更量を大きくして吐出圧力を大きく低下させ、給水温度に応じた最適な減圧装置の弁開度の変更を行うので、貯湯槽の湯容量を有効に利用でき、かつ効率の良い給湯加熱運転ができるものである。
【００１７】
請求項７に記載の発明は、予め設定された時間間隔ごとに減圧装置の弁開度の変更を行う制御手段を備えたことにより、沸き上げ完了直前時に最適な減圧装置の弁開度の変更を行うので、貯湯槽の湯容量を有効に利用でき、かつ効率の良い給湯加熱運転ができるものである。
【００１８】
請求項８に記載の発明は、減圧装置の弁開度の変更を行う時間間隔を沸き上げ完了に近づくほど小さくした制御手段を備えたことにより、沸き上げ完了に近づくほど吐出圧力の上昇が大きい時に減圧装置の弁開度の変更を多くして吐出圧力を大きく低下させ、最適な減圧装置の弁開度の変更を行うので、貯湯槽の湯容量を有効に利用でき、かつ効率の良い給湯加熱運転ができるものである。
【００１９】
請求項９に記載の発明は、沸き上げ完了直前検出手段として、循環ポンプの流量が最大流量になった時に、最大流量になっている時間を計測する時間計測手段を備えたことにより、循環ポンプの能力が、所定の時間の間、最大になったことを検出して減圧装置の弁開度の変更を行い、吐出圧力を低く押さえ、加熱運転を続けるので、高温の給水温度まで給湯加熱運転が可能となり、貯湯槽の湯容量を有効に利用できるものである。
【００２０】
請求項１０に記載の発明は、沸き上げ完了直前検出手段は、吐出圧力検出手段を備えたことを特徴とする請求項１に記載のヒートポンプ給湯機とすることにより、直接吐出圧力により制御するので、圧縮機のより確実な耐久性の向上を図ることが可能になる。
【００２１】
【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。なお、以下の各実施例において、図２０に示す従来の技術で説明したと同じ構成部材には同一符号を付して詳細な説明を省略し、異なる処を中心に説明する。
【００２２】
（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給湯機の構成図で、図２は同ヒートポンプ給湯機の運転時間に対する圧縮機の運転状態と減圧装置の弁開度と吐出圧力と給水温度とを示す説明図で、図３は同ヒートポンプ給湯機の貯湯槽の温度分布を示す説明図である。
【００２３】
図１において、冷媒対水熱交換器２の水側出口に設けた沸き上げ温度検出手段９からの信号で流量制御手段１０は、循環ポンプ６の回転数を制御して冷媒対水熱交換器２の出口水温（沸き上げ温度）をほぼ一定になるように沸き上げる。また、制御手段１１は、沸き上げ完了の直前を検出する沸き上げ完了直前検出手段１２からの信号で、減圧装置３の弁開度を制御するものである。
【００２４】
なお、沸き上げ完了直前検出手段１２として、ここでは一例として、冷媒対水熱交換器２の水側入口水温である給水温度を検出する給水温度検出手段８を用いる。また、減圧装置３として電動膨張弁（図示せず）等がある。
【００２５】
次に上記実施例の動作と作用について説明する。図２は横軸に運転時間を示し、縦軸に圧縮機の運転状態と減圧装置の弁開度と吐出圧力と給水温度とを示して、運転時間に対する圧縮機の運転状態と減圧装置の弁開度と吐出圧力と給水温度との関係を示したものである。従来例で説明したように、貯湯槽５の沸き上げ完了近くになると、冷媒対水熱交換器２に流入する給水温度は高くなる。
【００２６】
つまり、冷媒対水熱交換器２に流入する水が従来例で前述した湯水混合層の部分になると、同図に示すように、運転時間とともに給水温度が上昇する。そして、沸き上げ完了直前検出手段１２である給水温度検出手段８が（沸き上げ温度T1よりも低い温度である）沸き上げ完了直前検出温度Thを検出すると、この検出信号により制御手段１１は、減圧装置３の弁開度を大きくする（開く）。
【００２７】
この時、圧縮機の吐出圧力はP1からP2に減少する。その後、運転時間の経過とともに給水温度が更に上昇し、それに従って吐出圧力が上昇する。そして、給水温度検出手段８が、常用上限圧力Ｐになる給水温度T3aを検出すると、圧縮機を停止し加熱運転を終了する。なお、同図中の太い点線は、減圧装置３の弁開度の制御を行わない従来例の場合である。運転限界の給水温度がT3からT3aへと高くなり、運転範囲が大きくなることが明らかにできるとともに、有効になった湯層ができ、使えない湯層が図３に示すように従来例よりも少なくなり、貯湯槽の湯容量を有効に利用できる。
【００２８】
以上のように本実施例の発明においては、圧縮機、冷媒対水熱交換器、減圧装置、蒸発器を順次接続した冷媒循環回路と、貯湯槽、循環ポンプ、前記冷媒対水熱交換器を順次接続した給湯回路と、貯湯槽全体が沸き上がる直前を検出する沸き上げ完了直前検出手段と、前記沸き上げ完了直前検出手段からの信号が所定の信号になった時に、前記減圧装置の弁開度を開くように制御する制御手段とを備えたことにより、沸き上げ完了に近づき、圧縮機の吐出圧力が上昇する場合に、減圧装置の開度を開くように制御して吐出圧力を低く押さえ、高温の給水温度まで給湯加熱運転が可能となり、貯湯槽の湯容量を有効に利用できるものである。
【００２９】
（実施例２）
図４は本発明の実施例２におけるヒートポンプ給湯機の構成図で、図５は同ヒートポンプ給湯機の減圧装置の弁開度に対する吐出圧力を示す説明図で、図６は同ヒートポンプ給湯機の外気温度に対する減圧装置の弁開度の変更量と沸き上げ完了直前検出温度とを示す説明図である。
【００３０】
本実施例において、図１に示す実施例１と異なる点は、外気温度を検出するため蒸発器４の近傍に設けた外気温度検出手段１３と、外気温度に対する減圧装置３の弁開度の変更量を記憶している第一の記憶手段１４とを設け、かつ制御手段１１ａは沸き上げ完了直前検出手段１２の信号以外に、前記外気温度検出手段１３と第一の記憶手段１４の信号をとり込んで減圧装置３を制御する構成としていることである。
【００３１】
前記第一の記憶手段１４は、記憶している外気温度に対する減圧装置３の弁開度の変更量を、次のような関係の基で設定している。すなわち、図５は横軸に減圧装置３の弁開度を示し、外気温度をパラメータ（冬は例えば５℃、中間期は例えば１８℃、夏は例えば１８℃）にして、縦軸に吐出圧力を示して、ある給水温度の場合における減圧装置３の弁開度に対する吐出圧力の関係を示したものである。同図に示すように、減圧装置３の弁開度が大きくなれば、吐出圧力が減少する。そこで、吐出圧力をＰ１からＰ２に減少させるため減圧装置３の弁開度の変更量を求めれば、冬（例えば５℃）では△Ｓ１、中間期（例えば１８℃）では△Ｓ２、夏（例えば１８℃）では△Ｓ３となる。
【００３２】
図６は横軸に外気温度を示し、縦軸に減圧装置３の弁開度の変更量を示して、外気温度に対する減圧装置３の弁開度の変更量と沸き上げ完了直前検出温度との関係を示したものである。外気温度に対する減圧装置３における弁開度の変更量の関係は、図５で求めた外気温度（冬は５℃、中間期は１８℃、夏は１８℃）に対する変更量（冬は△Ｓ１、中間期は△Ｓ２、夏は△Ｓ３）の関係である。また、外気温度に対する沸き上げ完了直前検出温度の関係は、各外気温度（冬は例えば５℃、中間期は例えば１８℃、夏は例えば１８℃）において吐出圧力がP1になる給水温度（沸き上げ完了直前検出温度Th）を求めることによって決定できる。そして、これらの関係を表したものが図６であり、この図６の関係（テーブル）を第一の記憶手段１４に予め記憶させる。なお、図中で、実施例１の図１と同符号の部分は同一構成を示し、詳細な説明は省略する。
【００３３】
次に上記実施例の動作と作用について説明する。制御手段１１ａは、定期的に沸き上げ完了直前検出手段１２である給水温度検出手段８から給水温度を検出し、更に外気温度検出手段１３から外気温度を検出する。そして、第一の記憶手段１４に記憶させているテーブルから、外気温度に対する減圧装置３の弁開度の変更量と沸き上げ完了直前検出温度Thとを求める。そして、給水温度検出手段８から得た給水温度が沸き上げ完了直前検出温度Thより低ければ、減圧装置３の弁開度は変更せず、逆に、給水温度が沸き上げ完了直前検出温度Thより高ければ第一の記憶手段１４のテーブルから求めた減圧装置３の弁開度の変更量だけ減圧装置３の弁開度を変更する（開く）。減圧装置３の弁開度を変更すると吐出圧力はP1からP2に減少する。その後、実施例１で説明したように、運転時間の経過とともに給水温度が更に上昇し、それに従って吐出圧力が上昇する。そして、給水温度検出手段８が、図２に示す常用上限圧力Ｐになる給水温度T3aを検出すると、圧縮機を停止し、加熱運転を終了する。
【００３４】
以上のように本実施例の発明においては、減圧装置の弁開度の変更量は外気温度を検出する外気温度検出手段から得た外気温度に応じて決定する制御手段を備えたことにより、外気温度に応じた最適な減圧装置の弁開度の変更を行うので、貯湯槽の湯容量を有効に利用でき、かつ、効率の良い給湯加熱運転ができるものである。
【００３５】
（実施例３）
図７は本発明の実施例３におけるヒートポンプ給湯機の構成図で、図８は同ヒートポンプ給湯機の運転時間に対する給水温度と吐出圧力と減圧装置の弁開度と圧縮機の運転状態とを示す説明図である。本実施例において、図１に示す実施例１と異なる点は、給水温度記憶手段１５を設け、かつ制御手段１１ｂは沸き上げ完了直前検出手段１２の信号以外に、前記給水温度記憶手段１５の信号をとり込んで減圧装置３を制御する構成としていることである。
【００３６】
前記給水温度記憶手段１５は、記憶している給水温度を次のような関係の基で設定している。すなわち、図８は横軸に運転時間を示し、縦軸に給水温度と吐出圧力と減圧装置の弁開度と圧縮機の運転状態とを示し、運転時間に対する給水温度と吐出圧力と減圧装置の弁開度と圧縮機の運転状態との関係を示したものである。同図中に示すＴｈ１、Ｔｈ２（Ｔｈ１＜Ｔｈ２）は、沸き上げ完了直前検出温度Thで、それぞれ第一の沸き上げ完了直前検出温度、第二の沸き上げ完了直前検出温度である。この第一の沸き上げ完了直前検出温度Ｔｈ１と第二の沸き上げ完了直前検出温度Ｔｈ２とを給水温度記憶手段１５に記憶させている。なお、図中において図１に示す実施例１と同符号の部分は同一構成を示し、詳細な説明は省略する。
【００３７】
次に上記実施例の動作と作用について説明する。前述したように、貯湯槽５の沸き上げ完了近くになると、冷媒対水熱交換器２に流入する給水温度は高くなる。制御手段１１ｂは、定期的に沸き上げ完了直前検出手段１２である給水温度検出手段８から給水温度を検出し、更に給水温度記憶手段１５に記憶させている第一の沸き上げ完了直前検出温度Ｔｈ１を求める。そして、給水温度検出手段８から得た給水温度が第一の沸き上げ完了直前検出温度Ｔｈ１より低ければ、減圧装置３の弁開度は変更せず、逆に、給水温度が第一の沸き上げ完了直前検出温度Ｔｈ１より高ければ減圧装置３の弁開度を変更する（開く）。このように減圧装置３の弁開度を変更すると吐出圧力は減少する。その後も、制御手段１１ｂは、定期的に沸き上げ完了直前検出手段１２である給水温度検出手段８から給水温度を検出し、更に給水温度記憶手段１５に記憶させている第二の沸き上げ完了直前検出温度Ｔｈ２を求める。そして、給水温度検出手段８から得た給水温度が第二の沸き上げ完了直前検出温度Ｔｈ２より低ければ、減圧装置３の弁開度は変更せず、逆に、給水温度が第二の沸き上げ完了直前検出温度Ｔｈ２より高ければ減圧装置３の弁開度を変更する（開く）。更にこのように減圧装置３の弁開度を変更した時は同様に、圧縮機の吐出圧力は減少する。その後、実施例１で説明したように運転時間の経過とともに給水温度が更に上昇し、それに従って吐出圧力が上昇する。そして、給水温度検出手段８が、常用上限圧力Ｐになる給水温度T3aを検出すると、圧縮機を停止し、加熱運転を終了する。
【００３８】
以上のように本実施例の発明においては、予め決められた複数の給水温度毎に前記減圧装置の弁開度の変更を行う制御手段を備えたことにより、給水温度に応じた最適な減圧装置の弁開度の変更を行うので、有効な湯として利用できない無駄な領域がより少なくなるため、貯湯槽の湯容量を有効に利用でき、かつ効率の良い給湯加熱運転ができるものである。
【００３９】
また、本実施例では、沸き上げ完了直前検出温度Thとして２つの給水温度を設定したが、３つ以上の給水温度を設定しても、本実施例と同様の作用効果が得られる。
【００４０】
（実施例４）
図９は本発明の実施例４におけるヒートポンプ給湯機の構成図で、図１０は同ヒートポンプ給湯機の給水温度に対する吐出圧力と減圧装置の弁開度を示す説明図で、図１１は同ヒートポンプ給湯機の給水温度に対する減圧装置の弁開度の変更量を示す説明図である。
【００４１】
本実施例において、図７に示す実施例３と異なる点は、給水温度に対する減圧装置の弁開度の変更量を記憶する第二の記憶手段１６を設け、かつ制御手段１１ｃは沸き上げ完了直前検出手段１２と、第一の沸き上げ完了直前検出温度Ｔｈ１と第二の沸き上げ完了直前検出温度Ｔｈ２とを記憶している給水温度記憶手段１５の信号以外に、前記第二の記憶手段１６の信号をとり込んで減圧装置３を制御する構成としていることである。
【００４２】
前記第二の記憶手段１６は、記憶している給水温度に対する減圧装置の弁開度の変更量を次のような関係の基で設定している。すなわち、図１０は横軸に給水温度を示し、縦軸に吐出圧力と減圧装置の弁開度とを示して、給水温度に対する吐出圧力と減圧装置の弁開度との関係を示したものである。同図において、点線は減圧装置３の弁開度を一定とした場合である。同図から明らかなように、給水温度が高くなればなるほど急激に吐出圧力が高くなる。また、同図中に示すＴｈ１、Ｔｈ２、Ｔｈ３、Ｔｈ４、Ｔｈ５（Ｔｈ１＜Ｔｈ２＜Ｔｈ３＜Ｔｈ４＜Ｔｈ５）は、沸き上げ完了直前検出温度Thを示す給水温度で、それぞれ第一、第二、第三、第四、第五の沸き上げ完了直前検出温度である。この第一から第五の沸き上げ完了直前検出温度を給水温度記憶手段１５に記憶させている。そして、沸き上げ完了直前検出手段１２である給水温度検出手段８の検出した給水温度が、給水温度記憶手段１５に記憶させている沸き上げ完了直前検出温度Th（Ｔｈ１、Ｔｈ２、Ｔｈ３、Ｔｈ４、Ｔｈ５）以上になれば、減圧装置３の弁開度を変更（それぞれ△Ｓ１、△Ｓ２、△Ｓ３、△Ｓ４、△Ｓ５）する（開く）。この時の減圧装置３における弁開度の変更量を、同図に示すように、沸き上げ完了直前検出温度の高い方ほどより大きくする。つまり、沸き上げ完了直前検出温度Ｔｈ１＜Ｔｈ２＜Ｔｈ３＜Ｔｈ４＜Ｔｈ５の時、減圧装置３の弁開度の変更量を△Ｓ１＜△Ｓ２＜△Ｓ３＜△Ｓ４＜△Ｓ５とする。このようにすれば、同図の実線で示すように、吐出圧力の急激な上昇はなくなる。
【００４３】
また、図１１は横軸に給水温度を示し、縦軸に減圧装置３の弁開度の変更量を示して、給水温度に対する減圧装置３における弁開度の変更量の関係を示したものであり、この関係を第二の記憶手段１６に記憶させている。なお、図中において実施例３と同符号の部分は同一構成を示し、詳細な説明は省略する。
【００４４】
次に上記実施例の動作と作用について説明する。制御手段１１ｃは、定期的に沸き上げ完了直前検出手段１２である給水温度検出手段８の検出した給水温度を検出する。そして、給水温度記憶手段１５に記憶させている沸き上げ完了直前検出温度Th（Ｔｈ１、Ｔｈ２、Ｔｈ３、Ｔｈ４、Ｔｈ５）を求める。そして、給水温度検出手段８から求めた給水温度が沸き上げ完了直前検出温度Thより低ければ、減圧装置３の弁開度は変更せず、逆に、給水温度が沸き上げ完了直前検出温度Thより高ければ、第二の記憶手段１６に記憶している給水温度に対する減圧装置の弁開度の変更量（それぞれ△Ｓ１、△Ｓ２、△Ｓ３、△Ｓ４、△Ｓ５）だけ減圧装置３の弁開度を変更する（開く）。
【００４５】
以上のように本実施例の発明においては、給水温度が高いほど減圧装置の弁開度の変更量を大きくした制御手段を備えたことにより、吐出圧力の上昇が大きい高給水温度時に減圧装置の弁開度の変更量を大きくして吐出圧力を大きく低下させ、給水温度に応じた最適な減圧装置の弁開度の変更を行うので、貯湯槽の湯容量を有効に利用でき、かつ効率の良い給湯加熱運転ができるものである。
【００４６】
また、本実施例の発明では、沸き上げ完了直前検出温度Thとして５つの給水温度を設定したが、６つ以上の給水温度を設定しても、本実施例と同様の作用効果が得られる。
【００４７】
（実施例５）
図１２は本発明の実施例５におけるヒートポンプ給湯機の構成図で、図１３は同ヒートポンプ給湯機の運転時間に対する給水温度と減圧装置の弁開度と吐出圧力とを示す説明図である。本実施例において、図１に示す実施例１と異なる点はタイマー１７を設け、かつ制御御手段１１ｄは、沸き上げ完了直前検出手段１２の信号以外に、前記タイマー１７の信号をとり込んで減圧装置３を制御する構成としていることである。すなわち、制御手段１１ｄは、給水温度が沸き上げ完了直前検出温度Thになれば、タイマー１７により予め設定された所定の時間間隔△Ｔ毎に、減圧装置３の弁開度を大きくする制御を行うものである。
【００４８】
つまり、図１３は横軸に運転時間度を示し、縦軸に給水温度と減圧装置の弁開度と吐出圧力とを示して、運転時間に対する給水温度と減圧装置の弁開度と吐出圧力との関係を示したものである。前述したように、貯湯槽５の湯水混合層の部分になると運転時間とともに給水温度が上昇する。同図において、点線は減圧装置３の弁開度を一定とした場合であり、運転時間が経過して給水温度が高くなればなるほど急激に吐出圧力が高くなる。そこで、給水温度が、沸き上げ完了直前検出温度Thになれば、タイマー１７により予め設定された所定の時間間隔△Ｔ毎に、減圧装置３の弁開度を大きくする。このようにすれば、同図のように、減圧装置３の弁開度が一定の場合に比べて、吐出圧力（実線の部分）を低くすることができる。なお、図中において図１に示す実施例１と同符号の部分は同一構成を示し、詳細な説明は省略する。
【００４９】
次に上記実施例の動作と作用について説明する。すなわち、制御手段１１ｄは、定期的に沸き上げ完了直前検出手段１２である給水温度検出手段８から給水温度を検出する。そして、給水温度検出手段８から求めた給水温度が沸き上げ完了直前検出温度Thより高ければ、タイマー１７からの信号によって所定の時間間隔△Ｔ毎に段階的に減圧装置３の弁開度を開くものである。
【００５０】
以上のように本実施例の発明においては、予め設定された時間間隔ごとに減圧装置３の弁開度の変更を行う制御手段１１ｄを備えたことにより、沸き上げ完了直前時に最適な減圧装置の弁開度の変更を行うので、貯湯槽の湯容量を有効に利用でき、かつ効率の良い給湯加熱運転ができるものである。
【００５１】
（実施例６）
図１４は本発明の実施例６におけるヒートポンプ給湯機の構成図で、図１５は同ヒートポンプ給湯機の運転時間に対する給水温度と減圧装置の弁開度と吐出圧力とを示す説明図である。本実施例において、図１２に示す実施例５と異なる点は、減圧装置３の弁開度の変更を行う時間間隔を沸き上げ完了に近づくほど小さく設定した時間間隔記憶手段１８を設け、かつ制御御手段１１ｅは、沸き上げ完了直前検出手段１２の信号以外に、前記時間間隔記憶手段１８の信号に基くタイマー１７の信号をとり込んで、減圧装置３の弁開度の変更を行う時間間隔を、沸き上げ完了に近づくほど小さく制御する構成としていることである。
【００５２】
すなわち、図１５は横軸に運転時間度を示し、縦軸に給水温度と減圧装置の弁開度と吐出圧力とを示して、運転時間に対する給水温度と減圧装置の弁開度と吐出圧力との関係を示したものである。前述したように、貯湯槽５の湯水混合層の部分になると運転時間の経過とともに給水温度が上昇する。同図において、点線は減圧装置３の弁開度を一定とした場合であり、運転時間が経過して給水温度が高くなればなるほど急激に吐出圧力（点線の部分）が高くなる。そこで、給水温度が、第一の沸き上げ完了直前検出温度Ｔｈ１になれば、予め設定された所定の第一の時間間隔△T1毎に、減圧装置３の弁開度を段階的に大きくする。そして、給水温度が更に上昇し、給水温度が第二の沸き上げ完了直前検出温度Ｔｈ２になれば、前記第一の時間間隔△T1より小さい所定の第二の時間間隔△T2（△T2＜△T1）毎に、減圧装置３の弁開度を段階的に大きくする。
【００５３】
このように、吐出圧力が急激に上昇する高給水温度時に、減圧装置３の弁開度を修正する時間間隔を短くすれば、同図のように、減圧装置３の弁開度が一定の場合に比べて、吐出圧力（実線の部分）を低くすることができ、特に、急激な吐出圧力の上昇をなくすことができるため、給湯加熱運転の範囲を広げることができる。従って、前述した第一の時間間隔△T1と第二の時間間隔△T2とを時間間隔記憶手段１８に記憶させているのである。なお、図中において図１２に示す実施例５と同符号の部分は同一構成を示し、詳細な説明は省略する。
【００５４】
次に上記実施例の動作と作用について説明する。すなわち、制御手段１１ｅは、定期的に沸き上げ完了直前検出手段１２である給水温度検出手段８から給水温度を検出する。そして、給水温度検出手段８から求めた給水温度が第一の沸き上げ完了直前検出温度Ｔｈ１より高ければ、時間間隔記憶手段１８からの信号によって、第一の時間間隔△T1を検出する。そして、タイマー１７からの信号によって、第一の時間間隔△T1毎に減圧装置３の弁開度を段階的に開く。更に、給水温度が上昇し、給水温度検出手段８から求めた給水温度が第二の沸き上げ完了直前検出温度Ｔｈ２より高ければ、時間間隔記憶手段１８からの信号によって、第二の時間間隔△T2を検出する。そして、タイマー１７からの信号によって、第二の時間間隔△T2毎に減圧装置３の弁開度を段階的に開くものである。
【００５５】
以上のように本実施例の発明においては、減圧装置の弁開度の変更を行う時間間隔を沸き上げ完了に近づくほど小さくした制御手段を備えたことにより、沸き上げ完了に近づくほど吐出圧力の上昇が大きい時に減圧装置の弁開度の変更を多くして吐出圧力を大きく低下させ、最適な減圧装置の弁開度の変更を行うので、貯湯槽の湯容量を有効に利用でき、かつ効率の良い給湯加熱運転ができるものである。
【００５６】
また、本実施例では、減圧装置の弁開度の変更を行う時間間隔として２つの時間間隔（△T1、△T2）を設定したが、３つ以上の時間間隔を設定しても、本実施例と同様の作用効果が得られる。
【００５７】
（実施例７）
図１６は本発明の実施例７におけるヒートポンプ給湯機の構成図で、図１７は同ヒートポンプ給湯機の運転時間に対する給水温度と循環ポンプの回転数と流量と吐出圧力と減圧装置の弁開度とを示す説明図である。本実施例において、図１に示す実施例１と異なる点は、沸き上げ完了直前検出手段１２として、循環ポンプ６の流量が最大流量になっている時間を、流量検出手段１０を通じて計測する時間計測手段１９を設け、かつ制御手段１１ｆは前記時間計測手段１９の出力信号を受けて減圧装置３を制御する構成としていることである。なお、図中で実施例１と同符号の部分は同一構成を示し、詳細な説明は省略する。
【００５８】
次に上記実施例の動作と作用について説明する。図１７は横軸に運転時間度を示し、縦軸に給水温度と循環ポンプ６の回転数および流量と吐出圧力と減圧装置３の弁開度とを示して、運転時間に対する給水温度と循環ポンプ６の回転数および流量と吐出圧力と減圧装置３の弁開度との関係を示したものである。前述したように、冷媒対水熱交換器２の水側出口に設けられた沸き上げ温度検出手段９からの信号で流量制御手段１０は循環ポンプ６の回転数を制御して、冷媒対水熱交換器２の出口水温（沸き上げ温度）をほぼ一定になるように沸き上げる。今、貯湯槽５における湯水混合層の部分になると運転時間とともに給水温度が上昇するので、冷媒対水熱交換器２の水側流量が大きくなるように循環ポンプ６の回転数を増加させていく。ところが、循環ポンプ６の回転数が最大回転数に達してもなお給水温度が上昇する場合がある。この場合には、冷媒対水熱交換器２の出口水温である沸き上げ温度が上昇し、かつ、吐出圧力も急激に上昇する。そこで、循環ポンプ６の回転数が所定の運転時間続けて最大回転数になれば、減圧装置３の弁開度を開くように制御すれば、図１７に示すように吐出圧力が低下し、給湯加熱運転を続けることが可能になる。
【００５９】
すなわち、制御手段１１ｆは、定期的に沸き上げ完了直前検出手段１２である時間計測手段１９から循環ポンプ６の流量が最大流量になっている時間を検出する。そして、この検出した時間が制御手段１１ｆに予め設定した所定の運転時間より長ければ、時間計測手段１９からの信号によって減圧装置３の弁開度を開くのである。
【００６０】
以上のように、本実施例の発明においては、沸き上げ完了直前検出手段として、循環ポンプの流量が最大流量になった時に、最大流量になっている時間を計算する時間計測手段を備えたことにより、循環ポンプの能力が、所定の時間の間、最大になったことを検出して減圧装置の弁開度の変更を行い吐出圧力を低く押さえ加熱運転を続けるので、高温の給水温度まで給湯加熱運転が可能となり、貯湯槽の湯容量を有効に利用できるものである。
【００６１】
（実施例８）
図１８は本発明の実施例８におけるヒートポンプ給湯機の構成図で、図１９は同ヒートポンプ給湯機の運転時間に対する給水温度と吐出圧力と減圧装置の弁開度とを示す説明図である。本実施例において、図１に示す実施例１と異なる点は、沸上げ完了直前検出手段１２として、ヒートポンプの冷媒循環回路における圧縮機１の吐出側に接続し、吐出圧力を検出する吐出圧力検出手段２０を設け、かつ制御手段１１ｇは前記吐出圧力検出手段２０の出力信号を受けて減圧装置３を制御する構成としていることである。なお、図中で実施例１と同符号の部分は同一構成を示し、詳細な説明は省略する。
【００６２】
次に上記実施例の動作と作用について説明する。図１９は横軸に運転時間度を示し、縦軸に給水温度と吐出圧力と減圧装置の弁開度とを示して、運転時間に対する給水温度と吐出圧力と減圧装置の弁開度との関係を示したものである。前述したように、貯湯槽における湯水混合層の部分になると運転時間とともに給水温度が上昇し、これに伴って吐出圧力も高くなる。そこで、吐出圧力が基準圧力Ｐになれば、減圧装置３の弁開度を大きくする。その結果、吐出圧力を低下させることができる。
【００６３】
すなわち、制御手段１１ｇは、定期的に沸き上げ完了直前検出手段１２である吐出圧力検出手段２０から吐出圧力を検出する。そして、吐出圧力検出手段２０から求めた吐出圧力が、制御手段１１ｇに予め設定した基準圧力Ｐより高ければ、吐出圧力検出手段２０からの信号によって、減圧装置３の弁開度を開くのである。このような制御を制御手段１１ｇにより繰り返し行い、吐出圧力が基準圧力Ｐを越えないようにしている。
【００６４】
以上のように本実施例の発明においては、沸き上げ完了直前検出手段として吐出圧力検出手段を用い、検出した吐出圧力が設定された基準圧力になれば、減圧装置の弁開度を開くように制御する制御手段を備えたことにより、貯湯槽の湯容量を有効に利用でき、かつ直接吐出圧力で制御するので、圧縮機のより確実な耐久性の向上になるものである。
【００６５】
【発明の効果】
以上のように本発明によれば、沸き上げ完了に近づき、圧縮機の吐出圧力が上昇する場合に、減圧装置の弁開度を開くように制御し、吐出圧力を低く押さえ、高温の給水温度まで給湯加熱運転が可能になるので、有効な湯として利用できない無駄な領域がより少なくなるため、貯湯槽の湯容量を有効に利用できる。従って、従来と同じ大きさの貯湯槽でより大きな給湯負荷を満足し、逆に、従来と同じ大きさの給湯負荷を満足するためには、従来に比し小形の貯湯槽にできるので、設置の自由度が大きく、コスト低減もできる。更に、効率の良い給湯加熱運転ができる。
【図面の簡単な説明】
【図１】本発明の実施例１のヒートポンプ給湯機を示す構成図
【図２】同ヒートポンプ給湯機の運転時間に対する圧縮機の運転状態と減圧装置の弁開度と吐出圧力と給水温度とを示す説明図
【図３】同ヒートポンプ給湯機の貯湯槽の温度分布を示す説明図
【図４】本発明の実施例２のヒートポンプ給湯機を示す構成図
【図５】同ヒートポンプ給湯機の減圧装置の弁開度に対する吐出圧力を示す説明図
【図６】同ヒートポンプ給湯機の外気温度に対する減圧装置の弁開度の変更量と沸き上げ完了直前検出温度とを示す説明図
【図７】本発明の実施例３のヒートポンプ給湯機を示す構成図
【図８】同ヒートポンプ給湯機の運転時間に対する給水温度と吐出圧力と減圧装置の弁開度と圧縮機の運転状態とを示す説明図
【図９】本発明の実施例４のヒートポンプ給湯機を示す構成図
【図１０】同ヒートポンプ給湯機の給水温度に対する吐出圧力と減圧装置の弁開度を示す説明図
【図１１】同ヒートポンプ給湯機の給水温度に対する減圧装置の弁開度の変更量を示す説明図
【図１２】本発明の実施例５のヒートポンプ給湯機を示す構成図
【図１３】同ヒートポンプ給湯機の運転時間に対する給水温度と減圧装置の弁開度と吐出圧力とを示す説明図
【図１４】本発明の実施例６のヒートポンプ給湯機を示す構成図
【図１５】同ヒートポンプ給湯機の運転時間に対する給水温度と減圧装置の弁開度と吐出圧力とを示す説明図
【図１６】本発明の実施例７のヒートポンプ給湯機を示す構成図
【図１７】同ヒートポンプ給湯機の運転時間に対する給水温度と循環ポンプの回転数および流量と吐出圧力と減圧装置の弁開度とを示す説明図
【図１８】本発明の実施例８のヒートポンプ給湯機を示す構成図
【図１９】同ヒートポンプ給湯機の運転時間に対する給水温度と吐出圧力と減圧装置の弁開度とを示す説明図
【図２０】従来例におけるヒートポンプ給湯機を示す構成図
【図２１】同ヒートポンプ給湯機の貯湯槽の温度分布を示す説明図
【図２２】同ヒートポンプ給湯機の給水温度に対する吐出圧力を示す説明図
【符号の説明】
１圧縮機
２冷媒対水熱交換器
３減圧装置
４蒸発器
５貯湯槽
６循環ポンプ
８給水温度検出手段
１０流量制御手段
１１、１１ａ、１１ｂ、１１ｃ制御手段
１１ｄ、１１ｅ、１１ｆ、１１ｇ制御手段
１２沸き上げ完了直前検出手段
１３外気温度検出手段
１４第一の記憶手段
１５給水温度記憶手段
１６第二の記憶手段
１７タイマー
１８時間間隔記憶手段
１９時間計測手段
２０吐出圧力検出手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot water storage type heat pump water heater.
[0002]
[Prior art]
A conventional heat pump water heater of this type is shown in Japanese Patent Laid-Open No. 60-164157. FIG. 20 is a configuration diagram of a conventional heat pump water heater. In FIG. 20, a refrigerant circulation circuit comprising a compressor 1, a refrigerant-to-water heat exchanger 2, a decompression device 3, and an evaporator 4, a hot water tank 5, a circulation pump 6, the refrigerant-to-water heat exchanger 2, and an auxiliary heater The high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 1 flows into the refrigerant-to-water heat exchanger 2 and heats the water sent from the circulation pump 6. Then condense.
[0003]
The condensed and liquefied refrigerant is decompressed by the decompression device 3 and flows into the evaporator 4, where it absorbs atmospheric heat to evaporate and returns to the compressor 1. On the other hand, the hot water heated in the refrigerant-to-water heat exchanger 2 flows into the upper part of the hot water storage tank 5 and is gradually stored from above. Then, when the inlet water temperature of the refrigerant-to-water heat exchanger 2 reaches a set value, the feed water temperature detecting means 8 detects this, stops the heat pump operation by the compressor 1, and operates the auxiliary heater 7 alone. To switch to.
[0004]
[Problems to be solved by the invention]
However, in the configuration of the conventional example as described above, a hot water mixed layer is formed at the portion where the hot water in the hot water tank 5 is in contact with water with the elapse of the boiling operation time, and the layer gradually expands. FIG. 21 shows the temperature distribution of hot water in the hot water tank 5. In the figure, T1 is the boiling temperature (high temperature hot water), and T2 is the city water temperature (low temperature hot water). The above-mentioned hot / cold mixed layer is generated by heat conduction and convection between hot and cold hot water, and heat is transferred from the hot water to the low temperature hot water. Rise.
[0005]
Accordingly, when the boiling of the hot water tank 5 is nearly completed, the temperature of the feed water flowing into the refrigerant-to-water heat exchanger 2 increases, so that the discharge pressure of the compressor 1 increases and the winding temperature of the motor increases. The durability of the compressor 1 becomes a problem.
[0006]
FIG. 22 shows the relationship between the discharge pressure of the compressor 1 with respect to the feed water temperature, with the horizontal axis representing the feed water temperature flowing into the refrigerant-to-water heat exchanger 2 and the vertical axis representing the discharge pressure of the compressor 1 at that time. It is a thing. The pressure P in the figure is a normal upper limit pressure, and in order to guarantee the durability of the compressor 1, it is necessary to operate at or below this pressure in normal operation. The water supply temperature at pressure P is T3 from the figure.
[0007]
The lower limit of the effective hot water temperature is Tu (for example, 45 ° C.), and the above-described T3 and Tu are shown in FIG. In the cross-sectional view of the hot water tank 5 shown on the left side of the figure, the region below the hot water temperature T3 is a region where boiling can be performed, and the region above the Tu is a region that can be used as effective hot water. However, the area between the hot water temperatures T3 and Tu (shaded area) is an area that cannot be used as effective hot water.
[0008]
Thus, in the configuration of the conventional example, since the operation must be stopped in a state where the temperature of the water flowing through the refrigerant-to-water heat exchanger 2 is low, the lower part of the hot water tank 5 is stopped in a state of low temperature water. Therefore, the hot water capacity of the hot water storage tank 5 cannot be used effectively. Therefore, the amount of stored hot water is reduced and the hot water supply load cannot be satisfied. One way to solve this is to increase the capacity of the hot water tank 5.
[0009]
However, in this case, there is a problem that the installation area of the hot water tank 5 is increased, the degree of freedom of installation is limited, and the cost is increased. As another method, there is a method of increasing the amount of stored hot water by the independent operation of the auxiliary heater 7 after stopping the heat pump operation. However, in this case, since heating is performed with a heater or the like, there is a problem that power consumption increases and efficiency decreases.
[0010]
The present invention solves the above-described conventional problems, and can store hot water to the lower part of the hot water tank with low power consumption without any abnormal temperature rise and pressure rise of the compressor, and can effectively use the hot water capacity. An object of the present invention is to provide a heat pump water heater.
[0011]
[Means for Solving the Problems]
To solve the conventional problemsThe present invention also relates to a compressor, a refrigerant-to-water heat exchanger, a decompression device for controlling the flow rate of the refrigerant, a refrigerant circulation circuit having an evaporator, a hot water tank, a circulation pump, and a hot water supply circuit having the refrigerant-to-water heat exchanger. And a flow rate control means for controlling the flow rate of the circulation pump in order to make the boiling temperature which is the water-side outlet water temperature of the refrigerant-to-water heat exchanger, and the boiling point for detecting the hot and cold mixed layer in the hot water tank. And a control means for controlling the valve opening of the decompression device to open stepwise when the signal from the detection means immediately before the completion of boiling becomes a predetermined signal. Heat pump water heater that keeps the boiling temperature constant even if the temperature changesIs. Therefore, when the boiling pressure is nearing completion and the discharge pressure of the compressor rises, the opening of the decompression device is controlled to open and the discharge pressure is kept low.Even when the valve opening changes, the boiling temperature is kept constant.Therefore, the hot water supply heating operation can be performed up to a high water supply temperature.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 is a compressor, a refrigerant-to-water heat exchanger, a decompression device that controls the flow rate of the refrigerant, a refrigerant circulation circuit having an evaporator, a hot water tank, a circulation pump, and the refrigerant-to-water heat exchanger. A hot water supply circuit having flow rate, a flow rate control means for controlling the flow rate of the circulation pump in order to make the boiling temperature which is the water side outlet water temperature of the refrigerant-to-water heat exchanger, and the hot and cold mixed layer in the hot water storage tank Detecting means immediately before completion of boiling, and when the signal from the detecting means immediately before completion of boiling becomes a predetermined signal, the valve opening degree of the pressure reducing device is determined.Step by stepControl means for controlling to open, A heat pump water heater that keeps the boiling temperature constant even when the valve opening changesTherefore, when the compressor discharge pressure rises when it is close to the completion of boiling, the valve opening of the decompression device is controlled so that the discharge pressure is kept low and hot water heating operation can be performed up to a high water supply temperature. The hot water capacity of the hot water tank can be used effectively.
The invention described in claim 2The heat pump water heater according to claim 1, wherein the compressor is stopped when the detecting means immediately before the completion of boiling detects a predetermined temperature.
[0013]
The invention according to claim 3 is a compressor, a refrigerant-to-water heat exchanger, a decompression device that controls the flow rate of the refrigerant, a refrigerant circulation circuit having an evaporator, a hot water tank, a circulation pump, and the refrigerant-to-water heat exchanger. A hot water supply circuit having flow rate, a flow rate control means for controlling the flow rate of the circulation pump in order to make the boiling temperature which is the water outlet water temperature of the refrigerant to water heat exchanger constant, and the refrigerant provided in the hot water supply circuit A feed water temperature detecting means for detecting the temperature of the feed water before flowing into the water heat exchanger, the feed water temperature detecting meansAnd a control means for controlling the valve opening of the pressure reducing device to open stepwise when the signal from becomes a predetermined signal, and makes the boiling temperature constant even if the valve opening changesHeat pump water heaterToTherefore, when the compressor discharge pressure rises when it is close to the completion of boiling, the valve opening of the decompression device is controlled so that the discharge pressure is kept low and hot water heating operation can be performed up to a high water supply temperature. The hot water capacity of the hot water tank can be used effectively.
[0014]
The invention according to claim 4The heat pump water heater according to claim 3, wherein the compressor is stopped when a signal from the feed water temperature detecting means detects a predetermined temperature.
[0015]
Claim5The invention described in the above is a change of the valve opening of the pressure reducing device.amountIs equipped with a control means for determining the outside air temperature according to the outside air temperature obtained from the outside air temperature detecting means, so that the optimum valve opening of the decompression device is changed according to the outside air temperature. The hot water capacity can be used effectively, and an efficient hot water supply heating operation can be performed.
[0016]
Claim6According to the invention described in the above, as the feed water temperature is higher, the valve opening degree of the decompression device is changed.amountBy providing a control means with a large increase in discharge pressure, the amount of change in the valve opening of the pressure reducing device is increased at a high water supply temperature where the discharge pressure is greatly increased to greatly reduce the discharge pressure, and the optimum pressure reducing device according to the water supply temperature Therefore, the hot water capacity of the hot water storage tank can be used effectively, and an efficient hot water supply heating operation can be performed.
[0017]
Claim7Since the invention described in (1) includes a control means for changing the valve opening of the pressure reducing device at preset time intervals, the valve opening of the pressure reducing device is optimally changed immediately before the completion of boiling. In addition, the hot water capacity of the hot water tank can be used effectively, and an efficient hot water heating operation can be performed.
[0018]
Claim8The invention described in 1) includes a control unit that reduces the time interval for changing the valve opening degree of the decompression device as it approaches the completion of boiling, so that the decompression device increases when the discharge pressure increases as it approaches the completion of boiling. The discharge pressure is greatly reduced by changing the valve opening of the valve, and the valve opening of the optimum pressure reducing device is changed. Therefore, the hot water capacity of the hot water tank can be used effectively and efficient hot water heating operation is possible. It can be done.
[0019]
Claim9The invention described in 1) includes the time measuring means for measuring the time of the maximum flow rate when the flow rate of the circulation pump reaches the maximum flow rate as the detection means immediately before the completion of boiling. Detecting that the pressure has reached the maximum for a predetermined time, changing the valve opening of the decompression device, keeping the discharge pressure low, and continuing the heating operation, so that the hot water supply heating operation is possible up to a high water supply temperature The hot water capacity of the hot water tank can be used effectively.
[0020]
Claim10According to the invention described in the item 1, the detection unit immediately before the completion of boiling is provided with a discharge pressure detection unit, and the heat pump water heater according to claim 1 is controlled by the direct discharge pressure. It is possible to improve the durability more reliably.
[0021]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same components as those described in the prior art shown in FIG. 20 are denoted by the same reference numerals, detailed description thereof is omitted, and different points are mainly described.
[0022]
Example 1
FIG. 1 is a configuration diagram of a heat pump water heater in Embodiment 1 of the present invention, and FIG. 2 shows an operating state of the compressor, a valve opening degree of a decompression device, a discharge pressure, and a feed water temperature with respect to an operation time of the heat pump water heater. FIG. 3 is an explanatory view showing the temperature distribution of the hot water storage tank of the heat pump water heater.
[0023]
In FIG. 1, the flow rate control means 10 controls the rotational speed of the circulation pump 6 by a signal from the boiling temperature detection means 9 provided at the water-side outlet of the refrigerant-to-water heat exchanger 2 to control the refrigerant-to-water heat exchanger. The outlet water temperature of 2 (boiling temperature) is boiled so as to be substantially constant. The control means 11 controls the valve opening degree of the decompression device 3 by a signal from the boiling completion detection means 12 that detects immediately before the completion of boiling.
[0024]
In addition, as the detection means 12 immediately before the completion of boiling, here, as an example, the feed water temperature detection means 8 that detects the feed water temperature that is the water-side inlet water temperature of the refrigerant-to-water heat exchanger 2 is used. Further, the decompression device 3 includes an electric expansion valve (not shown).
[0025]
Next, the operation and action of the above embodiment will be described. FIG. 2 shows the operating time on the horizontal axis, the operating state of the compressor, the valve opening of the pressure reducing device, the discharge pressure, and the feed water temperature on the vertical axis, and the operating state of the compressor and the valve of the pressure reducing device with respect to the operating time. The relationship between an opening degree, discharge pressure, and feed water temperature is shown. As explained in the conventional example, when the boiling of the hot water tank 5 is nearly completed, the temperature of the feed water flowing into the refrigerant-to-water heat exchanger 2 increases.
[0026]
In other words, when the water flowing into the refrigerant-to-water heat exchanger 2 becomes a part of the hot water / mixing layer described above in the conventional example, the water supply temperature rises with the operation time as shown in FIG. When the feed water temperature detection means 8 which is the detection means 12 immediately before the completion of boiling detects the detection temperature Th immediately before the completion of boiling (which is a temperature lower than the boiling temperature T1), the control means 11 reduces the pressure by this detection signal. The valve opening of the device 3 is increased (opened).
[0027]
At this time, the discharge pressure of the compressor decreases from P1 to P2. Thereafter, as the operation time elapses, the feed water temperature further rises, and the discharge pressure rises accordingly. And if the feed water temperature detection means 8 detects the feed water temperature T3a used as the normal upper limit pressure P, a compressor will be stopped and a heating operation will be complete | finished. In addition, the thick dotted line in the same figure is the case of the prior art example which does not control the valve opening degree of the decompression device 3. It is clear that the water supply temperature at the operating limit increases from T3 to T3a, and the operating range is increased, and an effective hot water layer is formed. The hot water capacity of the hot water tank can be used effectively.
[0028]
As described above, in the invention of the present embodiment, a refrigerant circulation circuit in which a compressor, a refrigerant-to-water heat exchanger, a decompression device, and an evaporator are sequentially connected, a hot water tank, a circulation pump, and the refrigerant-to-water heat exchanger are provided. Sequentially connected hot water supply circuit, a boiling immediately preceding detection means for detecting immediately before the entire hot water tank is boiled, and a valve opening degree of the pressure reducing device when a signal from the immediately preceding boiling completion detecting means becomes a predetermined signal Control means to control the opening of the compressor, when the discharge pressure of the compressor approaches the completion of boiling and the discharge pressure of the compressor rises, the opening of the decompression device is controlled to open and the discharge pressure is kept low, Hot water supply heating operation is possible up to a high temperature of the hot water supply, and the hot water capacity of the hot water tank can be used effectively.
[0029]
(Example 2)
FIG. 4 is a configuration diagram of the heat pump water heater in Embodiment 2 of the present invention, FIG. 5 is an explanatory diagram showing discharge pressure with respect to the valve opening degree of the pressure reducing device of the heat pump water heater, and FIG. 6 is the outside air of the heat pump water heater. It is explanatory drawing which shows the variation | change_quantity of the valve opening degree of the decompression device with respect to temperature, and the detected temperature immediately before completion of boiling.
[0030]
In this embodiment, the difference from the first embodiment shown in FIG. 1 is that the outside air temperature detecting means 13 provided in the vicinity of the evaporator 4 for detecting the outside air temperature, and the change of the valve opening degree of the decompression device 3 with respect to the outside air temperature. A first storage means 14 for storing the amount, and the control means 11a takes signals of the outside temperature detection means 13 and the first storage means 14 in addition to the signal of the detection means 12 immediately before the completion of boiling. And the pressure reducing device 3 is controlled.
[0031]
The first storage means 14 sets a change amount of the valve opening of the pressure reducing device 3 with respect to the stored outside air temperature based on the following relationship. That is, FIG. 5 shows the valve opening of the decompression device 3 on the horizontal axis, the outside air temperature as a parameter (for example, 5 ° C. in winter, 18 ° C. in the intermediate period, 18 ° C. in summer), and the discharge pressure on the vertical axis. The relationship of the discharge pressure with respect to the valve opening degree of the decompression device 3 in the case of a certain feed water temperature is shown. As shown in the figure, the discharge pressure decreases as the valve opening of the decompression device 3 increases. Therefore, if the amount of change in the valve opening of the pressure reducing device 3 is calculated to reduce the discharge pressure from P1 to P2, ΔS1 in winter (eg, 5 ° C.), ΔS2 in the intermediate period (eg, 18 ° C.), and summer (eg, At 18 ° C., ΔS3 is obtained.
[0032]
FIG. 6 shows the outside air temperature on the horizontal axis and the change amount of the valve opening of the decompression device 3 on the vertical axis, and the change amount of the valve opening of the decompression device 3 relative to the outside air temperature and the detected temperature immediately before the completion of boiling. It shows the relationship. The relationship between the change amount of the valve opening in the decompression device 3 with respect to the outside air temperature is the change amount with respect to the outside air temperature (5 ° C. in winter, 18 ° C. in the intermediate period, 18 ° C. in summer) obtained in FIG. The relationship is ΔS2 for the interim period and ΔS3 for the summer. In addition, the relationship between the detected temperature immediately before the completion of boiling with respect to the outside air temperature is as follows: the feed water temperature (boiling up) at which the discharge pressure becomes P1 at each outside air temperature (for example, 5 ° C. in winter, 18 ° C. in the middle period, and 18 ° C. in summer) It can be determined by obtaining the detected temperature Th) immediately before completion. FIG. 6 shows these relationships, and the relationship (table) shown in FIG. 6 is stored in the first storage unit 14 in advance. In the figure, the same reference numerals as those in FIG. 1 of the first embodiment denote the same components, and detailed description thereof is omitted.
[0033]
Next, the operation and action of the above embodiment will be described. The control means 11 a periodically detects the feed water temperature from the feed water temperature detection means 8 which is the detection means 12 immediately before the completion of boiling, and further detects the outside air temperature from the outside air temperature detection means 13. And from the table memorize | stored in the 1st memory | storage means 14, the variation | change_quantity of the valve opening degree of the decompression device 3 with respect to external temperature and the detection temperature Th just before completion of boiling are calculated | required. If the feed water temperature obtained from the feed water temperature detecting means 8 is lower than the detected temperature Th immediately before the completion of boiling, the valve opening degree of the decompression device 3 is not changed, and conversely, the feed water temperature is higher than the detected temperature Th immediately before the completion of boiling. If it is higher, the valve opening degree of the pressure reducing device 3 is changed (opened) by the change amount of the valve opening degree of the pressure reducing device 3 obtained from the table of the first storage means 14. When the valve opening of the decompression device 3 is changed, the discharge pressure decreases from P1 to P2. Thereafter, as described in the first embodiment, the feed water temperature further rises as the operation time elapses, and the discharge pressure rises accordingly. And if the feed water temperature detection means 8 detects the feed water temperature T3a used as the normal upper limit pressure P shown in FIG. 2, a compressor will be stopped and a heating operation will be complete | finished.
[0034]
As described above, in the invention of the present embodiment, the amount of change in the valve opening of the pressure reducing device is provided with the control means that determines the outside air temperature according to the outside air temperature obtained from the outside air temperature detecting means. Since the valve opening of the optimum pressure reducing device is changed according to the temperature, the hot water capacity of the hot water tank can be used effectively and an efficient hot water heating operation can be performed.
[0035]
(Example 3)
FIG. 7 is a block diagram of the heat pump water heater in Embodiment 3 of the present invention, and FIG. 8 shows the feed water temperature, the discharge pressure, the valve opening of the decompression device, and the operating state of the compressor with respect to the operating time of the heat pump water heater. It is explanatory drawing. In the present embodiment, the difference from the first embodiment shown in FIG. 1 is that the feed water temperature storage means 15 is provided, and the control means 11b has a signal of the feed water temperature storage means 15 in addition to the signal of the detection means 12 immediately before the completion of boiling. The pressure reducing device 3 is controlled by taking
[0036]
The feed water temperature storage means 15 sets the stored feed water temperature based on the following relationship. That is, FIG. 8 shows the operation time on the horizontal axis, the feed water temperature, the discharge pressure, the valve opening of the decompression device, and the operating state of the compressor on the vertical axis, and the feed water temperature, the discharge pressure, and the decompression device with respect to the operation time. The relationship between a valve opening degree and the driving | running state of a compressor is shown. Th1 and Th2 (Th1 <Th2) shown in the figure are detection temperatures Th immediately before the completion of boiling, which are the first detection temperature immediately before the completion of boiling and the second detection temperature immediately before the completion of boiling, respectively. The detected temperature Th1 immediately before completion of the first boiling and the detected temperature Th2 immediately before completion of the second boiling are stored in the feed water temperature storage means 15. In the figure, the same reference numerals as those in the first embodiment shown in FIG. 1 denote the same components, and a detailed description thereof will be omitted.
[0037]
Next, the operation and action of the above embodiment will be described. As described above, the temperature of the feed water flowing into the refrigerant-to-water heat exchanger 2 becomes higher when the boiling of the hot water storage tank 5 is nearly completed. The control means 11b periodically detects the feed water temperature from the feed water temperature detection means 8 which is the detection means 12 immediately before the completion of boiling, and further detects the first detection temperature Th1 immediately before the completion of boiling stored in the feed water temperature storage means 15. Ask for. If the feed water temperature obtained from the feed water temperature detecting means 8 is lower than the detected temperature Th1 immediately before the completion of the first boiling, the valve opening of the pressure reducing device 3 is not changed, and conversely, the feed water temperature is raised to the first boiling. If it is higher than the detected temperature Th1 immediately before completion, the valve opening of the decompression device 3 is changed (opened). Thus, when the valve opening degree of the decompression device 3 is changed, the discharge pressure decreases. Thereafter, the control means 11b periodically detects the feed water temperature from the feed water temperature detection means 8 which is the detection means 12 immediately before the completion of boiling, and immediately before the completion of the second boiling which is stored in the feed water temperature storage means 15. The detected temperature Th2 is obtained. If the feed water temperature obtained from the feed water temperature detecting means 8 is lower than the detected temperature Th2 immediately before the completion of the second boiling, the valve opening of the decompression device 3 is not changed, and conversely, the feed water temperature is raised to the second boiling temperature. If it is higher than the detection temperature Th2 immediately before completion, the valve opening of the decompression device 3 is changed (opened). Further, when the valve opening degree of the pressure reducing device 3 is changed in this way, the discharge pressure of the compressor is similarly reduced. Thereafter, as described in the first embodiment, the feed water temperature further rises as the operation time elapses, and the discharge pressure rises accordingly. And if the feed water temperature detection means 8 detects the feed water temperature T3a used as the normal upper limit pressure P, a compressor will be stopped and a heating operation will be complete | finished.
[0038]
As described above, in the invention of the present embodiment, the optimum pressure reducing device according to the water supply temperature is provided by including the control means for changing the valve opening of the pressure reducing device for each of a plurality of predetermined water supply temperatures. Therefore, the wasteful area that cannot be used as effective hot water is reduced, so that the hot water capacity of the hot water tank can be used effectively and an efficient hot water supply heating operation can be performed.
[0039]
Further, in this embodiment, two feed water temperatures are set as the detected temperature Th immediately before the completion of boiling, but even if three or more feed water temperatures are set, the same effects as in this embodiment can be obtained.
[0040]
(Example 4)
FIG. 9 is a configuration diagram of a heat pump water heater in Embodiment 4 of the present invention, FIG. 10 is an explanatory diagram showing discharge pressure with respect to the feed water temperature of the heat pump water heater and the valve opening of the decompression device, and FIG. 11 is the heat pump water heater. It is explanatory drawing which shows the change amount of the valve opening degree of the decompression device with respect to the feed water temperature of a machine.
[0041]
In the present embodiment, the difference from the third embodiment shown in FIG. 7 is that the second storage means 16 for storing the amount of change in the valve opening of the pressure reducing device with respect to the feed water temperature is provided, and the control means 11c is immediately before the completion of the boiling. In addition to the signal of the feed water temperature storage means 15 that stores the detection means 12 and the detection temperature Th1 immediately before the first boiling completion and the detection temperature Th2 immediately before the second boiling completion, the second storage means 16 In other words, the decompression device 3 is controlled by taking a signal.
[0042]
The said 2nd memory | storage means 16 has set the change amount of the valve opening degree of the decompression device with respect to the memorize | stored water supply temperature based on the following relationship. That is, FIG. 10 shows the relationship between the discharge pressure with respect to the feed water temperature and the valve opening of the decompression device, with the horizontal axis representing the feed water temperature and the vertical axis representing the discharge pressure and the valve opening of the decompression device. is there. In the figure, a dotted line is a case where the valve opening degree of the decompression device 3 is made constant. As is apparent from the figure, the discharge pressure increases rapidly as the feed water temperature increases. Further, Th1, Th2, Th3, Th4, Th5 (Th1 <Th2 <Th3 <Th4 <Th5) shown in the figure are the feed water temperatures indicating the detected temperature Th immediately before the completion of boiling, respectively, The detected temperatures immediately before completion of the third, fourth, and fifth boiling. The detected temperatures immediately before completion of the first to fifth boiling are stored in the feed water temperature storage means 15. Then, the feed water temperature detected by the feed water temperature detection means 8, which is the detection means 12 immediately before the completion of boiling, is detected temperature Th (Th 1, Th 2, Th 3, Th 4, Th 5) stored in the feed water temperature storage means 15. ) If this is the case, the valve opening of the decompression device 3 is changed (ΔS1, ΔS2, ΔS3, ΔS4, ΔS5, respectively) (open). At this time, the amount of change in the valve opening in the decompression device 3 is made larger as the detected temperature immediately before the completion of boiling is higher, as shown in FIG. That is, when the detected temperature immediately before the completion of boiling is Th1 <Th2 <Th3 <Th4 <Th5, the change amount of the valve opening of the pressure reducing device 3 is set to ΔS1 <ΔS2 <ΔS3 <ΔS4 <ΔS5. In this way, as shown by the solid line in FIG.
[0043]
FIG. 11 shows the relationship between the amount of change in the valve opening in the pressure reducing device 3 relative to the water supply temperature, with the horizontal axis representing the feed water temperature and the vertical axis representing the amount of change in the valve opening of the pressure reducing device 3. Yes, this relationship is stored in the second storage means 16. In the figure, the same reference numerals as those in the third embodiment denote the same components, and a detailed description thereof will be omitted.
[0044]
Next, the operation and action of the above embodiment will be described. The control means 11c periodically detects the feed water temperature detected by the feed water temperature detection means 8 which is the detection means 12 immediately before the completion of boiling. Then, the detected temperature Th (Th1, Th2, Th3, Th4, Th5) immediately before completion of boiling stored in the feed water temperature storage means 15 is obtained. And if the feed water temperature calculated | required from the feed water temperature detection means 8 is lower than the detection temperature Th just before a boiling completion, the valve opening degree of the decompression device 3 will not be changed, conversely, the feed water temperature will be more than the detection temperature Th just before a boiling completion. If it is higher, the valve opening of the pressure reducing device 3 is changed by the amount of change in the valve opening of the pressure reducing device relative to the feed water temperature stored in the second storage means 16 (ΔS1, ΔS2, ΔS3, ΔS4, ΔS5, respectively). Change the degree (open).
[0045]
As described above, in the invention of the present embodiment, by providing the control means that increases the change amount of the valve opening of the pressure reducing device as the feed water temperature is higher, the increase in the discharge pressure is large. The amount of change in the valve opening is increased to greatly reduce the discharge pressure, and the optimum valve opening of the decompression device is changed according to the feed water temperature, so that the hot water capacity of the hot water tank can be used effectively and efficient. Good hot water supply heating operation is possible.
[0046]
Further, in the invention of this embodiment, five water supply temperatures are set as the detection temperature Th immediately before the completion of boiling, but even if six or more water supply temperatures are set, the same effect as this embodiment can be obtained.
[0047]
(Example 5)
FIG. 12 is a configuration diagram of a heat pump water heater in Embodiment 5 of the present invention, and FIG. 13 is an explanatory diagram showing a feed water temperature, a valve opening degree of a decompression device, and a discharge pressure with respect to the operation time of the heat pump water heater. In the present embodiment, the difference from the first embodiment shown in FIG. 1 is that a timer 17 is provided, and the control means 11d takes in the signal of the timer 17 in addition to the signal of the detection means 12 immediately before the completion of boiling and reduces the pressure. In other words, the device 3 is configured to be controlled. That is, the control means 11d performs control to increase the valve opening degree of the decompression device 3 every predetermined time interval ΔT preset by the timer 17 when the feed water temperature reaches the detected temperature Th immediately before the completion of boiling. Is.
[0048]
That is, FIG. 13 shows the operating time on the horizontal axis, the water supply temperature, the valve opening of the pressure reducing device, and the discharge pressure on the vertical axis, and the water supply temperature, the valve opening of the pressure reducing device, and the discharge pressure with respect to the operating time. This shows the relationship. As described above, when the hot water / water mixing layer portion of the hot water tank 5 is reached, the water supply temperature rises with the operation time. In the figure, a dotted line is a case where the valve opening degree of the decompression device 3 is constant, and the discharge pressure increases rapidly as the feed water temperature increases as the operating time elapses. Therefore, when the feed water temperature reaches the detection temperature Th immediately before the completion of boiling, the valve opening of the decompression device 3 is increased at every predetermined time interval ΔT set in advance by the timer 17. If it does in this way, as shown in the figure, compared with the case where the valve opening degree of the decompression device 3 is constant, discharge pressure (part of a continuous line) can be made low. In the figure, the same reference numerals as those in the first embodiment shown in FIG. 1 denote the same components, and a detailed description thereof will be omitted.
[0049]
Next, the operation and action of the above embodiment will be described. That is, the control unit 11d periodically detects the feed water temperature from the feed water temperature detection unit 8 which is the detection unit 12 immediately before the completion of boiling. And if the feed water temperature calculated | required from the feed water temperature detection means 8 is higher than the detection temperature Th just before a boiling completion, the valve opening degree of the decompression device 3 will be opened step by step for every predetermined time interval (DELTA) T by the signal from the timer 17. Is.
[0050]
As described above, in the invention of this embodiment, the control unit 11d that changes the valve opening degree of the decompression device 3 at preset time intervals is provided, so that the optimum decompression device immediately before the completion of boiling is obtained. Since the valve opening is changed, the hot water capacity of the hot water tank can be used effectively and an efficient hot water supply heating operation can be performed.
[0051]
(Example 6)
FIG. 14 is a configuration diagram of a heat pump water heater in Embodiment 6 of the present invention, and FIG. 15 is an explanatory diagram showing a feed water temperature, a valve opening degree of a decompression device, and a discharge pressure with respect to an operation time of the heat pump water heater. In the present embodiment, the difference from the fifth embodiment shown in FIG. 12 is that a time interval storage means 18 is provided, in which the time interval for changing the valve opening of the decompression device 3 is set smaller as the heating is closer to completion, and control is performed. The control unit 11e takes in the signal of the timer 17 based on the signal of the time interval storage unit 18 in addition to the signal of the detection unit 12 immediately before the completion of boiling, and sets the time interval for changing the valve opening of the decompression device 3. In other words, the configuration is such that the control is made smaller as the boiling is completed.
[0052]
That is, FIG. 15 shows the operating time on the horizontal axis, the water supply temperature, the valve opening of the pressure reducing device, and the discharge pressure on the vertical axis, and the water supply temperature, the valve opening of the pressure reducing device, and the discharge pressure with respect to the operating time. This shows the relationship. As described above, when the hot water storage layer 5 of the hot water tank 5 is reached, the temperature of the water supply rises with the passage of operating time. In the figure, a dotted line is a case where the valve opening degree of the decompression device 3 is constant, and the discharge pressure (dotted line portion) increases rapidly as the feed water temperature rises after the operation time has elapsed. Therefore, when the feed water temperature reaches the detected temperature Th1 immediately before the completion of the first boiling, the valve opening of the pressure reducing device 3 is increased stepwise at a predetermined first time interval ΔT1. When the feed water temperature further rises and the feed water temperature reaches the detected temperature Th2 immediately before the completion of the second boiling, a predetermined second time interval ΔT2 (ΔT2 <Δ) smaller than the first time interval ΔT1. Every time T1), the valve opening of the pressure reducing device 3 is increased stepwise.
[0053]
In this way, when the time interval for correcting the valve opening of the pressure reducing device 3 is shortened at a high water supply temperature at which the discharge pressure rapidly increases, the valve opening of the pressure reducing device 3 is constant as shown in FIG. In comparison with the above, the discharge pressure (solid line portion) can be reduced, and in particular, since a sudden increase in the discharge pressure can be eliminated, the range of the hot water supply heating operation can be expanded. Therefore, the first time interval ΔT1 and the second time interval ΔT2 described above are stored in the time interval storage means 18. In the figure, the same reference numerals as those in the fifth embodiment shown in FIG. 12 denote the same components, and a detailed description thereof will be omitted.
[0054]
Next, the operation and action of the above embodiment will be described. That is, the control unit 11e periodically detects the feed water temperature from the feed water temperature detection unit 8 which is the detection unit 12 immediately before the completion of boiling. And if the feed water temperature calculated | required from the feed water temperature detection means 8 is higher than the detection temperature Th1 immediately before completion of the first boiling, the first time interval ΔT1 is detected by a signal from the time interval storage means 18. And the valve opening degree of the decompression device 3 is opened stepwise by the signal from the timer 17 every first time interval ΔT1. Further, if the feed water temperature rises and the feed water temperature obtained from the feed water temperature detecting means 8 is higher than the detected temperature Th2 immediately before the completion of the second boiling, the second time interval ΔT2 is detected by a signal from the time interval storage means 18. Is detected. And the valve opening degree of the decompression device 3 is opened stepwise by the signal from the timer 17 every second time interval ΔT2.
[0055]
As described above, in the invention of the present embodiment, by providing the control means that decreases the time interval for changing the valve opening of the decompression device as it approaches the completion of boiling, the discharge pressure decreases as it approaches the completion of boiling. When the increase is large, the valve opening of the pressure reducing device is increased to greatly reduce the discharge pressure, and the valve opening of the optimal pressure reducing device is changed, so that the hot water capacity of the hot water tank can be used effectively and efficiently. A hot water supply heating operation is possible.
[0056]
In this embodiment, two time intervals (ΔT1, ΔT2) are set as the time intervals for changing the valve opening of the decompression device. However, even if three or more time intervals are set, this embodiment is implemented. The same effect as the example can be obtained.
[0057]
(Example 7)
FIG. 16 is a block diagram of a heat pump water heater in Embodiment 7 of the present invention, and FIG. 17 shows the feed water temperature, the number of rotations of the circulation pump, the flow rate, the discharge pressure, the valve opening degree of the decompression device with respect to the operation time of the heat pump water heater. It is explanatory drawing which shows. In the present embodiment, the difference from the first embodiment shown in FIG. 1 is that time measurement is performed by measuring the time when the flow rate of the circulation pump 6 is the maximum flow rate through the flow rate detection means 10 as the detection means 12 immediately before the completion of boiling. Means 19 is provided, and the control means 11 f is configured to receive the output signal of the time measuring means 19 and control the decompression device 3. In addition, the part of a code | symbol same as Example 1 in the figure shows the same structure, and detailed description is abbreviate | omitted.
[0058]
Next, the operation and action of the above embodiment will be described. FIG. 17 shows the operation time on the horizontal axis, and the water supply temperature, the rotational speed and flow rate of the circulation pump 6, the discharge pressure, and the valve opening of the decompression device 3 on the vertical axis. 6 shows the relationship between the rotational speed and flow rate of 6, the discharge pressure, and the valve opening of the decompression device 3. As described above, the flow rate control means 10 controls the rotational speed of the circulation pump 6 by the signal from the boiling temperature detection means 9 provided at the water-side outlet of the refrigerant-to-water heat exchanger 2, and the refrigerant-to-water heat The outlet water temperature (boiling temperature) of the exchanger 2 is boiled so as to be substantially constant. Now, when the hot water storage layer 5 in the hot water tank 5 becomes a portion of the hot water / water mixture, the water supply temperature rises with the operating time, so the rotational speed of the circulation pump 6 is increased so that the water-side flow rate of the refrigerant-to-water heat exchanger 2 increases. . However, even if the rotation speed of the circulation pump 6 reaches the maximum rotation speed, the feed water temperature may still rise. In this case, the boiling temperature that is the outlet water temperature of the refrigerant-to-water heat exchanger 2 is increased, and the discharge pressure is also rapidly increased. Therefore, if the rotation speed of the circulation pump 6 reaches the maximum rotation speed for a predetermined operating time, the discharge pressure decreases as shown in FIG. It becomes possible to continue the heating operation.
[0059]
That is, the control unit 11f periodically detects the time when the flow rate of the circulation pump 6 is the maximum flow rate from the time measurement unit 19 which is the detection unit 12 immediately before the completion of boiling. And if this detected time is longer than the predetermined operation time preset in the control means 11f, the valve opening degree of the decompression device 3 is opened by the signal from the time measuring means 19.
[0060]
As described above, in the invention of the present embodiment, as the detection means immediately before the completion of boiling, the time measuring means for calculating the time when the flow rate of the circulation pump reaches the maximum flow rate is provided. Therefore, it is detected that the capacity of the circulation pump is maximized for a predetermined time, and the valve opening of the decompression device is changed to keep the discharge operation low and the heating operation is continued. Heating operation is possible, and the hot water capacity of the hot water tank can be used effectively.
[0061]
(Example 8)
FIG. 18 is a configuration diagram of a heat pump water heater in Embodiment 8 of the present invention, and FIG. 19 is an explanatory diagram showing a feed water temperature, a discharge pressure, and a valve opening degree of the decompression device with respect to the operation time of the heat pump water heater. In the present embodiment, the difference from the first embodiment shown in FIG. 1 is that the detection means 12 immediately before the completion of boiling is connected to the discharge side of the compressor 1 in the refrigerant circulation circuit of the heat pump, and discharge pressure detection for detecting the discharge pressure. Means 20 is provided, and the control means 11g is configured to control the decompression device 3 in response to the output signal of the discharge pressure detection means 20. In addition, the part of a code | symbol same as Example 1 in the figure shows the same structure, and detailed description is abbreviate | omitted.
[0062]
Next, the operation and action of the above embodiment will be described. FIG. 19 shows the operation time on the horizontal axis, the water supply temperature, the discharge pressure, and the valve opening of the pressure reducing device on the vertical axis, and the relationship between the water supply temperature, the discharge pressure, and the valve opening of the pressure reducing device with respect to the operation time. Is shown. As described above, when the hot water / water mixing layer portion of the hot water storage tank is reached, the water supply temperature rises with the operation time, and the discharge pressure increases accordingly. Therefore, when the discharge pressure reaches the reference pressure P, the valve opening degree of the decompression device 3 is increased. As a result, the discharge pressure can be reduced.
[0063]
That is, the control means 11g periodically detects the discharge pressure from the discharge pressure detection means 20 that is the detection means 12 immediately before the completion of boiling. And if the discharge pressure calculated | required from the discharge pressure detection means 20 is higher than the reference pressure P preset to the control means 11g, the valve opening degree of the decompression device 3 will be opened with the signal from the discharge pressure detection means 20. Such control is repeatedly performed by the control means 11g so that the discharge pressure does not exceed the reference pressure P.
[0064]
As described above, in the invention of the present embodiment, the discharge pressure detection means is used as the detection means immediately before the completion of boiling, and when the detected discharge pressure reaches the set reference pressure, the valve opening of the decompression device is opened. By providing the control means for controlling, the hot water capacity of the hot water tank can be used effectively and directly controlled by the discharge pressure, so that more reliable durability of the compressor can be improved.
[0065]
【The invention's effect】
As aboveBookAccording to the invention, when the discharge pressure of the compressor approaches the completion of boiling, the valve opening of the decompression device is controlled to be opened, the discharge pressure is kept low, and the hot water supply heating operation is performed until the hot water supply temperature is reached. Since it becomes possible, since there are fewer useless areas that cannot be used as effective hot water, the hot water capacity of the hot water tank can be used effectively. Therefore, in order to satisfy a larger hot water supply load with a hot water storage tank of the same size as the conventional one, and conversely, to satisfy a hot water supply load of the same size as the conventional one, it can be made a smaller hot water storage tank than before. The degree of freedom is large and the cost can be reduced. Furthermore, an efficient hot water supply heating operation can be performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a heat pump water heater according to a first embodiment of the present invention.
FIG. 2 is an explanatory view showing the operating state of the compressor, the valve opening degree of the pressure reducing device, the discharge pressure, and the feed water temperature with respect to the operating time of the heat pump water heater.
FIG. 3 is an explanatory diagram showing temperature distribution in a hot water storage tank of the heat pump water heater
FIG. 4 is a configuration diagram showing a heat pump water heater according to a second embodiment of the present invention.
FIG. 5 is an explanatory diagram showing a discharge pressure with respect to a valve opening degree of the pressure reducing device of the heat pump water heater.
FIG. 6 is an explanatory diagram showing a change amount of the valve opening of the pressure reducing device with respect to the outside air temperature of the heat pump water heater and a detected temperature immediately before the completion of boiling.
FIG. 7 is a block diagram showing a heat pump water heater according to a third embodiment of the present invention.
FIG. 8 is an explanatory diagram showing the feed water temperature, the discharge pressure, the valve opening of the pressure reducing device, and the operating state of the compressor with respect to the operating time of the heat pump water heater.
FIG. 9 is a block diagram showing a heat pump water heater according to a fourth embodiment of the present invention.
FIG. 10 is an explanatory diagram showing the discharge pressure with respect to the feed water temperature of the heat pump water heater and the valve opening of the pressure reducing device.
FIG. 11 is an explanatory view showing a change amount of the valve opening of the pressure reducing device with respect to the feed water temperature of the heat pump water heater.
FIG. 12 is a block diagram showing a heat pump water heater according to a fifth embodiment of the present invention.
FIG. 13 is an explanatory diagram showing a feed water temperature, a valve opening degree of a pressure reducing device, and a discharge pressure with respect to an operation time of the heat pump water heater.
FIG. 14 is a configuration diagram showing a heat pump water heater according to a sixth embodiment of the present invention.
FIG. 15 is an explanatory diagram showing the feed water temperature, the valve opening degree of the pressure reducing device, and the discharge pressure with respect to the operation time of the heat pump water heater.
FIG. 16 is a block diagram showing a heat pump water heater according to a seventh embodiment of the present invention.
FIG. 17 is an explanatory diagram showing the feed water temperature, the rotation speed and flow rate of the circulation pump, the discharge pressure, and the valve opening of the pressure reducing device with respect to the operation time of the heat pump water heater.
FIG. 18 is a configuration diagram showing a heat pump water heater according to an eighth embodiment of the present invention.
FIG. 19 is an explanatory diagram showing the feed water temperature, the discharge pressure, and the valve opening of the pressure reducing device with respect to the operation time of the heat pump water heater.
FIG. 20 is a configuration diagram showing a heat pump water heater in a conventional example.
FIG. 21 is an explanatory view showing the temperature distribution of the hot water storage tank of the heat pump water heater.
FIG. 22 is an explanatory diagram showing the discharge pressure with respect to the feed water temperature of the heat pump water heater.
[Explanation of symbols]
1 Compressor
2 Refrigerant-to-water heat exchanger
3 Pressure reducing device
4 Evaporator
5 Hot water storage tank
6 Circulation pump
8 Water supply temperature detection means
10 Flow control means
11, 11a, 11b, 11c Control means
11d, 11e, 11f, 11g Control means
12 Detection means immediately before completion of boiling
13 Outside air temperature detection means
14 First storage means
15 Water supply temperature storage means
16 Second storage means
17 Timer
18 time interval storage means
19 Time measurement means
20 Discharge pressure detection means

Claims

A compressor, a refrigerant-to-water heat exchanger, a decompression device that controls the flow rate of the refrigerant, a refrigerant circulation circuit having an evaporator, a hot water tank, a circulation pump, a hot water supply circuit having the refrigerant-to-water heat exchanger, and the refrigerant pair A flow rate control means for controlling the flow rate of the circulation pump in order to make the boiling temperature that is the water-side outlet water temperature of the water heat exchanger, and a detection means immediately before the completion of boiling that detects the hot water / mixed layer in the hot water tank. And a control means for controlling the valve opening of the decompression device to open stepwise when the signal from the detection means immediately before the completion of boiling becomes a predetermined signal, even if the valve opening changes A heat pump water heater that keeps the boiling temperature constant .

The heat pump water heater according to claim 1, wherein the compressor is stopped when the detecting means immediately before the completion of boiling detects a predetermined temperature.

A compressor, a refrigerant-to-water heat exchanger, a decompression device that controls the flow rate of the refrigerant, a refrigerant circulation circuit having an evaporator, a hot water tank, a circulation pump, a hot water supply circuit having the refrigerant-to-water heat exchanger, and the refrigerant pair Flow rate control means for controlling the flow rate of the circulation pump in order to make the boiling temperature, which is the water-side outlet water temperature of the water heat exchanger, constant, and before flowing into the refrigerant-to-water heat exchanger provided in the hot water supply circuit Control means for controlling the valve opening of the pressure reducing device to open stepwise when a signal from the water supply temperature detection means becomes a predetermined signal. A heat pump water heater that keeps the boiling temperature constant even when the valve opening changes .

The heat pump water heater according to claim 3, wherein the compressor is stopped when a signal from the feed water temperature detecting means detects a predetermined temperature.

The heat pump water heater according to any one of claims 1 to 4 , wherein the control means controls the amount of change in the valve opening of the decompression device in accordance with the outside air temperature detected by the outside air temperature detecting means.

The heat pump water heater according to any one of claims 1 to 4 , wherein the control means controls the change amount of the valve opening of the decompression device to be larger as the feed water temperature is higher.

The heat pump water heater according to any one of claims 1 to 4 , wherein the control means changes the valve opening degree of the decompression device at predetermined time intervals.

6. The heat pump water heater according to claim 5, wherein the control means decreases the time interval of change of the valve opening degree in the decompression device as the heating is completed.

A compressor, a refrigerant-to-water heat exchanger, a decompression device that controls the flow rate of the refrigerant, a refrigerant circulation circuit having an evaporator, a hot water tank, a circulation pump, a hot water supply circuit having the refrigerant-to-water heat exchanger, and the refrigerant pair A flow rate control means for controlling the flow rate of the circulation pump in order to make the boiling temperature that is the water-side outlet water temperature of the water heat exchanger, and a detection means immediately before the completion of boiling that detects the hot water / mixed layer in the hot water tank. And a control means for controlling the valve opening of the pressure reducing device to open when the signal from the detection means immediately before the completion of boiling becomes a predetermined signal, the detection means immediately before the completion of boiling is a circulating pump A heat pump water heater comprising a time measuring means for calculating a time when the maximum flow rate is reached when the flow rate of the gas reaches the maximum flow rate .

The heat pump water heater according to claim 1, wherein the detection means immediately before completion of boiling comprises discharge pressure detection means.