JP2004100978A

JP2004100978A - Heat pump hot-water supply device

Info

Publication number: JP2004100978A
Application number: JP2002259777A
Authority: JP
Inventors: Keijiro Kunimoto; 國本　啓次郎; Takeji Watanabe; 渡辺　竹司; Masahiro Ohama; 尾浜　昌宏; Ryuta Kondo; 近藤　龍太; Satoshi Matsumoto; 松本　聡; Yoshitsugu Nishiyama; 西山　吉継; Koji Oka; 岡　浩二; Tatsumura Mo; 毛　立群; Seiichi Yasuki; 安木　誠一; Haruo Terai; 寺井　春夫
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2002-09-05
Filing date: 2002-09-05
Publication date: 2004-04-02
Anticipated expiration: 2022-09-05
Also published as: JP3801122B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump hot-water supply device capable of enhancing responsiveness and stability. <P>SOLUTION: This heat pump hot-water supply device is constituted by providing a water amount adjusting means 18 for adjusting water amount in a water flow passage 9 in the heat pump hot-water supply device which heats the water flow passage 9 by a refrigerant circulation circuit 7 and gives hot water to a hot-water terminal 12 directly when supplying hot water. When heating water amount in the water flow passage 9 is insufficient, water amount is reduced to maintain the temperature of supply hot water at a predetermined temperature. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、ヒートポンプ給湯装置に関するものである。
【０００２】
【従来の技術】
従来のヒートポンプ給湯装置としては、特許文献１に記載されているような給湯装置が提案されていた。この特許文献１におけるヒートポンプ給湯装置は図６に示すように、閉回路に構成される冷媒流路１で圧縮機２、放熱器３、減圧手段４、吸熱器５が接続された冷媒循環回路７と、放熱器３の冷媒流路ａ８と熱交換を行う水流路９を備えた熱交換器１０と、この水流路９に水道水を供給する給水管１１と、前記水流路９とシャワーや蛇口等の給湯端末１２とを接続する給湯回路１３と、給湯回路１３に設け給湯温度を検出する温度センサ１４と、圧縮機２の回転数を制御するインバータ１５を備え、圧縮機２を温度センサ１４の検出温度と設定温度との差に応じてインバータ１５の出力周波数を変換するようにしていた。すなわち従来の給湯装置では設定温度に対して給湯温度が低い場合は圧縮機２の回転数を上げ、給湯温度が高い場合は回転数を下げるように制御するようにしていた。
【０００３】
【特許文献１】
特開平２−２２３７６７号公報
【０００４】
【発明が解決しようとする課題】
しかし、上記従来例の給湯装置の構成では、給湯時における給湯負荷が一定ではない。特に流量は使用者が給湯目的によってさまざまに変化させるために給湯負荷は大きく変ってしまう。例えば家庭用の給湯の場合、シャワーや風呂への湯張りに給湯する場合は１０〜２０Ｌ／ｍｉｎの大流量となるが、台所で食器を洗う場合や洗面への給湯では３〜５Ｌ／ｍｉｎと少流量である。また、季節による給水温度の変化によっても給湯負荷は大きく変る。
【０００５】
こうした流量や水温の変化により大きくかわる給湯負荷を、従来のヒートポンプ給湯装置のように給湯温度と設定温度の差により圧縮機の回転数を変えて給湯熱量を制御するだけでは、給湯負荷がヒートポンプ装置の給湯加熱能力を超えてしまうと、目標とする温度より低い温度の湯が出てしまい、使用者に不快感を与えてしまう問題があった。
【０００６】
また、従来例のようなヒートポンプ給湯装置は給湯の開始時に冷媒循環回路全体の圧力や温度の立上がりに時間を要するため、熱交換器の水流路からの出湯温度の上昇に遅れが生じる。この給湯開始時に従来の構成では、給湯温度と設定温度の差だけで圧縮機の回転数を設定するだけなので、大流量の給湯では目標の湯温に達するのに時間がかかっていた。
【０００７】
以上のように従来のヒートポンプ給湯装置では大流量などの給湯負荷が大きい場合に目標温度の給湯ができなっかったり、目標温度に達するのに時間がかかったりといった問題があった。
【０００８】
本発明は、上記従来の課題を解決するもので、湯温の制御性がよく、湯温の立上りの早いヒートポンプ給湯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】
本発明は上記課題を解決するために、本発明のヒートポンプ給湯装置は、水流路の水量を調節する水量調節手段を設けたヒートポンプ給湯装置とする。
【００１０】
この発明によれば、水量調節手段が水流路の水量を調節して給湯を行うので、給湯負荷が冷媒循環回路としての最大能力を超える場合でも、能力に見合った水量に調整することにより、所定の温度の給湯が可能となる。また、給湯開始時の出湯温度の上昇も早くなる。
【００１１】
【発明の実施の形態】
請求項１に記載の発明のヒートポンプ給湯装置は、圧縮機と放熱器と減圧手段と吸熱器とを含む冷媒循環回路と、前記放熱器と熱交換を行う水流路を備えた熱交換器と、前記水流路に水道水を供給する給水管と、前記水流路から給湯端末へと通水するように接続する給湯回路と、前記水流路の水量を調節する水量調節手段とを有するヒートポンプ給湯装置とする。
【００１２】
この発明によれば、水量調節手段により熱交換器の水流路を流れる水量を調整するので、給湯負荷が冷媒循環回路の熱交換器の最大能力を超える場合でも、水量を低下させることにより給湯負荷を最大能力より低く抑えることができ、出湯温度が下がることなく所定温度を維持することができる。
【００１３】
請求項２に記載の発明のヒートポンプ給湯装置は、請求項１記載の構成に、給湯回路への給湯熱量である給湯負荷を求める給湯負荷検知手段と、熱交換器での加熱量を検知する熱量検知手段とを設け、前記給湯負荷検知手段の値が前記熱量検知手段の値を超える場合に水量調整手段により水量を低下させるものである。
【００１４】
この発明によれば、給湯負荷と加熱量を比較して給湯負荷に対して加熱量が不足する場合に流量を低下させて、出湯温度の低下を防止するものである。したがって、必要な場合だけ流量を低下させるので、通常の給湯負荷では流量低下がなく、例えばシャワーと台所の給湯が重なったりした、大流量での使用時に加熱量が不足した場合のみ流量を低下させるので、流量低下の頻度を最小限に抑えることができる。
【００１５】
請求項３に記載の発明のヒートポンプ給湯装置は、請求項２の構成に給水管の給水温度を検出する水温検知手段と、給湯の目標温度を設定する温度設定手段と、給湯回路の流量を検出する流量検知手段とを設け、請求項２に記載の給湯負荷検知手段を、前記水温検知手段と温度設定手段と流量検知手段の値の少なくともひとつから給湯負荷を求めるようにしたものである。
【００１６】
給湯負荷は、給湯の目標温度と給水温度との偏差に流量を乗じた値に比例するので、本発明によれば、前記水温検知手段と温度設定手段と流量検知手段の値から給湯負荷を算定することにより、正確な給湯負荷を求めることができる。
【００１７】
請求項４に記載の発明のヒートポンプ給湯装置は、請求項２または３に記載の構成に外気温度を検出する外気温度検知手段と、給水管の給水温度を検出する水温検知手段と、給湯の目標温度を設定する温度設定手段とを設け、請求項２または３に記載の熱量検知手段を、前記外気温度検知手段と水温検知手段と温度設定手段の値の少なくともひとつから熱交換器での加熱量を求めるようにしたものである。
【００１８】
この発明の冷媒循環回路の熱交換器での最大加熱量は、外気温度と給水温度と目標温度の３点の条件でほぼ求まるので、この３点から最大加熱量を正確に求めることができる。したがって、この値と給湯負荷を比較すれば、熱量不足が判定できる。
【００１９】
請求項５に記載の発明のヒートポンプ給湯装置は、請求項２〜４のいずれか１項に記載の水量調節手段による水量低下量を、給湯負荷検知手段の値と熱量検知手段の値とが一致するように水量を低下させるようにしたものである。
【００２０】
この発明によれば、最小限の水量低下で目標の出湯温度が得られる。
【００２１】
請求項６に記載の発明のヒートポンプ給湯装置は、圧縮機と放熱器と減圧手段と吸熱器とを含む冷媒循環回路と、前記放熱器と熱交換を行う水流路を備えた熱交換器と、前記水流路に水道水を供給する給水管と、前記水流路から給湯端末へと通水するように接続する給湯回路と、前記水流路の出湯温度を検出する湯温検知手段と、給湯の目標温度を設定する温度設定手段と、前記温度設定手段の設定値と湯温検知手段の検出値に応じて圧縮機の周波数と減圧手段とを制御する加熱制御手段と、前記水流路の水量を調節する水量調節手段とを備え、前記加熱制御手段が圧縮機の周波数を上限に設定した場合に、前記水量調節手段により水量を低下させるものである。
【００２２】
この発明によれば、圧縮器の周波数が上限に達することで、給湯負荷に対して熱交換量の不足を検知して、水量を低下するようにしたものであるので、熱量不足が明確に判定でき、水量調節の開始や終了の判定が容易に行える。
【００２３】
請求項７に記載の発明のヒートポンプ給湯装置は、圧縮機と放熱器と減圧手段と吸熱器とを含む冷媒循環回路と、前記放熱器と熱交換を行う水流路を備えた熱交換器と、前記水流路に水道水を供給する給水管と、前記水流路から給湯端末へと通水するように接続する給湯回路と、前記水流路の出湯温度を検出する湯温検知手段と、給湯の目標温度を設定する温度設定手段と、前記温度設定手段の設定値と湯温検知手段の検出値に応じて圧縮機の周波数と減圧手段とを制御する加熱制御手段と、前記水流路の水量を調節する水量調節手段とを備え、前記出湯温度が目標温度に達しない場合に、前記水量調節手段により水量を低下させるものである。
【００２４】
この発明によれば、出湯温度が目標に達しない場合に、水量調整手段の水量を低下させるので、出湯温度を常に目標値近傍に維持することができる。
【００２５】
請求項８に記載の発明のヒートポンプ給湯装置は、請求項７の構成に温度設定手段の設定する目標温度より低い第２の目標値を設定し、給湯開始から所定時間以降に出湯温度が、前記第２の目標温度以下であれば、請求項７に記載水量調節手段により水量を低下させるものである。
【００２６】
この発明によれば、給湯負荷に対して熱交換量不足を明確に判定し、水量調節の誤作動を防止できる。
【００２７】
請求項９に記載の発明のヒートポンプ給湯装置は、請求項１〜８のいずれか１に記載のヒートポンプ給湯装置の給湯開始時に水量調節手段により水量を低下させるものである。
【００２８】
給湯開始時における冷媒循環回路の温度や圧力の立ち上がり時間は、水流路に流れる水量が多いと熱交換器から取られる熱量も多くなるために長くなる。そのため、水流路からの出湯温度の上昇速度も遅くなり、目標温度に到達するまでに長い時間を要するが、本発明によれば、給湯開始時に水量調節手段により水量を低下させるので、冷媒循環回路や熱交換器の温度上昇を早め、出湯温度が目標温度に到達する時間を短縮することができる。
【００２９】
請求項１０に記載の発明のヒートポンプ給湯装置は、請求項９に記載の構成で、水流路の出湯温度が所定値に達した場合に水量調節手段による水量の低下を解除するものである。
【００３０】
この発明によれば、水流路の出湯温度が所定値に達するまでは水量を低下させることにより、出湯温度の上昇速度を早めて、所定値に達した段階で水量低下を解除するので、それ以降本来の給湯流量で給湯ができる。
【００３１】
請求項１１に記載の発明のヒートポンプ給湯装置は、請求項９または１０に記載の構成で、給湯開始から所定時間後に水量調節手段による水量を低下を解除するものである。
【００３２】
この発明によれば、給湯開始後所定時間までは水量を低下させることにより、出湯温度の上昇速度を早めて、所定時間に水量低下を解除するので、それ以降本来の給湯流量で給湯ができる。
【００３３】
請求項１２に記載の発明のヒートポンプ給湯装置は、請求項１に記載の構成で、水流路の水量に上限を設け、前記上限を超えないように水量調節手段を制御するものである。
【００３４】
この発明によれば、水量が上限を超えないので、水量が多過ぎて出湯温度が低下してしまうことがない。
【００３５】
請求項１３に記載の発明のヒートポンプ給湯装置は、請求項１２に記載の水量に上限を、給湯負荷が熱交換器での最大加熱量超えないように定めたものである。
【００３６】
この発明によれば、給湯負荷が最大加熱量を超えない水量に制限して出湯することができるので、出湯温度が目標温度より低下してしまうことがない。
【００３７】
請求項１４に記載の発明のヒートポンプ給湯装置は、請求項１〜１３のいずれか１項に記載の冷媒循環回路が、冷媒の圧力が臨界圧力以上となる超臨界ヒートポンプサイクルであり、前記臨界圧力以上に昇圧された冷媒により熱交換器の水流路の流水を加熱する構成である。
【００３８】
この発明によれば、熱交換器の放熱器を流れる冷媒は、圧縮機で臨界圧力以上に加圧されているので、熱交換器の水流路の流水により熱を奪われて温度低下しても凝縮することがない。したがって熱交換器全域で冷媒と水とに温度差を形成しやすくなり、高温の湯が得られ、かつ熱交換効率を高くできる。
【００３９】
【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、従来例および各実施例において、同じ構成、同じ動作をする部分については同一符号を付与し、詳細な説明を省略する。
【００４０】
（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式給湯装置の構成図である。図１において、７は冷媒循環回路で、圧縮機２、放熱器３、減圧手段４、吸熱器５が冷媒流路１により閉回路に接続されている。この冷媒循環回路７は、例えば炭酸ガス（ＣＯ２）を冷媒として使用し、高圧側の冷媒圧力が冷媒の臨界圧以上となる超臨界ヒートポンプサイクルを使用している。そして圧縮機２は、内蔵する電動モータ（図示しない）によって駆動され、吸引した冷媒を臨界圧力を超える圧力まで圧縮して吐出する。また、１０は放熱器３の冷媒流路ａ８と熱交換を行う水流路９を備えた熱交換器である。この水流路９に水道水を直接供給する給水管１１と、水流路９から出湯される湯をシャワー１６や蛇口１７等より成る給湯端末１２の通水させるための給湯回路１３が接続されている。そして１８は水流路９の水量を調節する水量調節手段で、電動の絞り弁により構成され給水管１１に設けている。
【００４１】
１９は制御手段で、給湯回路１３への給湯熱量である給湯負荷を求める給湯負荷検知手段２０と、熱交換器１０での水流路９の加熱量を検知する熱量検知手段２１と、圧縮機の周波数と減圧手段とを制御する加熱制御手段２２とを有している。
【００４２】
制御手段１９は、予め水量調節手段１８である絞り弁を所定量だけ駆動させ、給湯開始時の水量を低下させるように制御するとともに、給湯負荷検知手段２０の値が熱量検知手段２１の値を超える場合に、給湯負荷検知手段２０の値が熱量検知手段２１の値と一致するように水量調整手段１８により水流路９の水量を低下させるように制御する。
【００４３】
給水管１１には、給湯回路１３の流量を検出する流量検知手段２３と、熱交換器１０への給水温度を検出する水温検知手段２４が設けられている。そして給湯回路１３には水流路９からの出湯温度を検出する湯温検知手段２５が設けられている。２６は給湯の目標温度を設定する温度設定手段で、使用者が任意に温度を設定する。２７は気温を検出する外気温度検知手段である。
【００４４】
熱交換器１０は、冷媒流路ａ８の流れ方向と水流路９の流れ方向を対向流とし、各流路間を熱移動が容易になるように密着して構成している。この構成により冷媒流路ａ８と水流路９の伝熱が均一化し、熱交換効率がよくなる。また、高温の出湯も可能になる。
【００４５】
加熱制御手段２２は、圧縮機２の回転数を変更する周波数制御手段２８を備え、湯温検知手段２５と温度設定手段２６とのそれぞれが出力する出湯温度と目標温度との偏差が少なくなるように圧縮機２の周波数を公知のＰＩＤ（図示せず）により制御する。また、加熱制御手段２２は圧縮機２の冷媒吐出温度が所定の温度で、かつ冷媒循環回路７の圧力バランスを適性になるように減圧手段４の開度を制御する。
【００４６】
図２は実施例１における給湯開始時の水量調整手段１８の制御フローチャートである。図２において、３０は給湯中であるかを判定する。判定条件は流量検知手段２３が水量を検知したら給湯中と判定する。そして、水量がなく停止中と判定した場合は、３１に進む。ここでは給湯が停止してから１０分が経過したかを判定し、１０分が経過していれば、３２で水量調整手段１８の初期開度６０％を設定する。３１で１０分未満であると判定された場合は、３２の初期開度の設定を行わない。３１における１０分は、給湯の再起動時に水量を減少させて行うかどうかを決定する時間であり、冷媒循環回路７および熱交換器１０の冷却速度により設定するもので、冷えやすい条件であれば短い時間を設定し、冷えにくい条件であれば長い時間を設定するものである。
【００４７】
３０において給湯中と判定されれば３４へ進み、ここでは給湯開始から５分が経過したかどうかを判定し、５分が経過していれば、３５で水量調整手段１８の開度を全開１００％に戻す設定を行う。３４で５分未満であっても、３６で出湯温度Ｔｈｗが目標温度Ｔｓｅｔ−５Ｋを超えていれば、３５で水量調整手段１８の開度を全開に戻す設定を行う。そして、３４と３６の条件が成り立たない場合は水量調整手段１８の開度は初期開度のままとなる。
【００４８】
なお３２における初期開度６０％は、使用者に違和感なく水量を低減できるレベルで、出湯温度の立上りが早くなる値に設定する必要があり、予め実験的に決定すべき値である。
【００４９】
図３は実施例１における給湯時の水量調整手段１８の制御フローチャートである。図３において、４０は給湯負荷検知手段２０の給湯負荷算定を示す。ここでは、水温検知手段２４の検出する水温Ｔｗ（℃）と温度設定手段２６の設定する目標温度Ｔｓｅｔ（℃）との差に、流量検知手段２３の検出する流量Ｗ（Ｌ／ｍｉｎ）を乗じて、これに変換係数（６０／８６０）を乗じて給湯負荷Ｑｈｗ（ｋＷ）を求めている。なお、算出精度は悪くなるが給湯負荷の算定は水温を代表的な固定値としてもよいし、目標温度を固定値としてもよい。これによれば水温検知手段２４や温度設定手段２６が不要になったり、故障時でも稼動できたりする。
【００５０】
４１では熱量検知手段２１での加熱量Ｑｈｘ（ｋＷ）の設定を示す。これは、外気温度検知手段２７の検出する外気温度Ｔｏ（℃）と水温検知手段２４の水温Ｔｗから加熱量のテーブル４２から加熱量Ｑｈｘを読み込む。このテーブル４２の値は外気温度と水温の組合わせ条件における最大加熱量を予め実験により求めて設定しておく。このテーブルは数式でもよい。また、外気温度と水温と目標温度の３元の加熱量のテーブルとしてもよいし、外気温度と水温と目標温度の中から別の２つの要素からなる２元のデータでもよいし、加熱量の制度は悪くなるが、それぞれひとつの要素だけの１元のテーブルでもよい。これにより実験量が少なくかつメモリーが小さくできる。
【００５１】
４３は給湯負荷Ｑｈｗが加熱量Ｑｈｘを超える条件の場合は、４４で水量調整手段１８による水量低下のための開度低減設定を行う。一方４３でＱｈｗの方がＱｈｘより小さければ、４５で水量調整手段１８による水量復帰のための開度増加設定を行う。ここでの制御は、給湯負荷が加熱量を超える条件の場合に、給湯負荷が加熱量と一致するように水量を低下させるように作用する。そして４６、４７で開度低減の上限値を定め、４８，４９で開度低減の下限値を定めている。下限値として−７０％を設定しているのは異常時等により水量調整手段１８の絞りが進んでも最低３０％の開度を確保して、全閉になって給湯停止に到らないようにしている。
【００５２】
５０は水量調整手段１８の開度設定を行う。ここで図２で説明した給湯開始時の開度Ｘｉに低減開度Ｘｄを加算して最終の開度設定Ｘを求める。そして、５１で水量調整手段１８を設定された開度に駆動する。
【００５３】
以上の構成において、その動作、作用について説明する。蛇口１７が開かれると給水管１１から水道水が流れ込み始める。これを流量検知手段２３が検知し制御手段１９に信号が送られ、圧縮機２が起動する。
【００５４】
このとき水量調整手段１８は初期開度に絞られているので、水量は抑制されて出湯される。したがって、冷媒循環回路７の放熱手段３から水流路９への熱交換量が抑制せれ、圧縮機２や熱交換器１０の温度上昇速度が早くなり、水流路９からの出湯温度の温度上昇速度が早くなる。そして出湯温度が（目標温度−５Ｋ）以上に上昇したら水量調整手段１８により絞られた初期開度が解除されて、全開に復帰する。このとき圧縮機２や熱交換器１０は十分に圧力や温度が上昇しているので、水量を復帰させても出湯温度が低下することなく目標温度に到達することができる。
【００５５】
加熱制御手段２２では出湯温度と目標温度との偏差に基づいて圧縮機２の周波数を制御する。そして、圧縮機２から吐出される高温高圧の冷媒ガスは放熱器３へ流入し、水流路９を流れる水を加熱する。そして、加熱された水は給湯回路１３を経て給湯端末１２から出湯する。一方、放熱器３で冷却された冷媒は減圧手段４で減圧されて吸熱器５に流入し、ここで大気熱、太陽熱など自然エネルギーを吸熱して蒸発ガス化し、圧縮機２に戻る。従って、出湯を検出して、すぐに圧縮機１からの高温高圧の冷媒ガスが放熱器３に流入し、水を加熱し、そのまま給湯端末１２から出湯利用できる。
【００５６】
給湯中の加熱制御手段２２では、出湯温度と目標温度との偏差から公知のＰＩＤ制御を用いて周波数を算定する。すなわち、出湯温度のフィードバック制御がおこなわれる。ここでの制御定数である比例ゲインや積分係数や微分係数は、制御の応答性と安定性を両立するための最適な値を予め設定しておく必要がある。なおフィードバック制御は、ＰＩ制御でもＰ制御でもファジーやニューロ制御でもよい。
【００５７】
給湯中に２ヶ所以上の給湯などの大流量での給湯が発生し、熱交換器１０での最大加熱量を超える給湯負荷が発生した場合は、制御手段１９が水量調整手段１８を絞り方向に駆動し、給湯負荷が最大加熱量とほぼ一致するまで水量を減少させるので、出湯温度は大幅に低下することなく目標温度を維持することができる。
【００５８】
また、大流量から通常の流量へと変化した場合でも、給湯負荷が最大加熱量を下回れば、水量調整手段１８での絞りは水量低下から水量復帰に変り全開運転に戻るので使用者に違和感なく給湯運転ができる。
【００５９】
なお、実施例１では冷媒循環回路を、冷媒の圧力が臨界圧力以上となる超臨界冷媒循環回路としたが、もちろん一般の臨界圧力以下の冷媒循環回路でもよい。
【００６０】
（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装置の給湯時の水量調整手段１８の制御フローチャートである。なお、実施例１の給湯装置と同一構造のものは同一符号を付与し、説明を省略する。図４において、実施例１の構成と異なるところは、５５の水量上限の設定値により水量調整手段１８の制御を行う点にある。５５では４１により求めた最大の加熱量Ｑｈｘ（ｋＷ）と目標温度Ｔｓｅｔ（℃）と水温Ｔｗ（℃）より水量の上限ＷＬ（Ｌ／ｍｉｎ）を算出する。そして、５６により流量検知手段２３により検出された水量Ｗ（Ｌ／ｍｉｎ）が水量の上限ＷＬを超えないかを判定し、超えた場合は４４で水量調整手段１８による水量低下のための開度低減設定を行う。一方超えない場合は、４５で水量調整手段１８による水量復帰のための開度増加設定を行う。
【００６１】
以上のように実施例２では、最大の加熱量から水量の上限を設定し、水量の検出値がこの上限を超えないように制御するので、加熱量不足による出湯温度低下が防止できる。
【００６２】
（実施例３）
図５は本発明の実施例３におけるヒートポンプ給湯装置の給湯時の水量調整手段１８の制御フローチャートである。なお、実施例１の給湯装置と同一構造のものは同一符号を付与し、説明を省略する。図５において、実施例１の構成と異なるところは、温度設定手段２６の設定する目標温度より５Ｋ低い第２の目標値を設定し、給湯開始から３分経過以降に出湯温度が、この第２の目標温度以下でかつ、加熱制御手段２２が圧縮機２の周波数を上限に設定した場合に水量を低下させる点にある。具体的に次のような制御すなる。
【００６３】
６０では加熱制御手段２２の圧縮機２の周波数設定が行われる。すなわち出湯温度Ｔｈｗと目標温度Ｔｓｅｔとの偏差から公知のＰＩＤ制御を用いて周波数Ｆを算定する。
【００６４】
６１は給湯開始から３分経過したかを判定する。３分未満であれば、６２で水量低下の開度低減設定は０％とし、水量低下禁止とする。６１で３分以上経過したと判定すると、６３に進む。
【００６５】
６３は圧縮機２の制御周波数Ｆが上限値Ｆｍａｘ以上で、出湯温度Ｔｈｗが目標温度Ｔｓｅｔ−３Ｋ未満であれば、４４で水量調整手段１８による水量低下のための開度低減設定を行う。一方６３の条件が成り立たない場合は、４５で水量調整手段１８による水量復帰のための開度増加設定を行う。
【００６６】
６１の給湯開始から３分は、まだシステム全体がの能力や温度が立ち上がるまでの時間を設定するもので、この値はシステムの条件により異なる。
【００６７】
６３における判定は周波数Ｆにより最大加熱量に達しているかを判定し、出湯温度Ｔｈｗにより能力不足かどうかを判定している。そして、この両者により、最大加熱量に達して能力不足に陥っていると判定される。なお、実施例３では周波数Ｆと出湯温度Ｔｈｗの両者の状態で判定することにより、判定精度を向上させているが、それぞれ単独で判定しても充分に精度よく能力不足を判定できる。
【００６８】
なお、上記１〜３の実施例では貯湯槽や蓄熱材を持たない、完全な瞬間式の給湯装置で説明したが、給湯時にヒートポンプで加熱した湯を直接給湯端末に供給する構成であれば、熱交換器に並列に貯湯槽を有していたり、また熱交換器に直列に貯湯槽を有していたり、さらには水側回路や冷媒回路に蓄熱材を有していても同様の効果が得られる。
【００６９】
【発明の効果】
以上のように、本発明によれば、給湯制御の応答性と安定性がよいヒートポンプ給湯装置を提供することができる。
【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給湯装置の構成図
【図２】本発明の実施例１における給湯開始時の水量調整手段の制御フローチャート
【図３】本発明の実施例１における給湯時の水量調整手段の制御フローチャート
【図４】本発明の実施例２における給湯時の水量調整手段の制御フローチャート
【図５】本発明の実施例３における給湯時の水量調整手段の制御フローチャート
【図６】従来のヒートポンプ給湯装置の構成図
【符号の説明】
２　圧縮機
３　放熱器
４　減圧手段
５　吸熱器
７　冷媒循環回路
９　水流路
１０　熱交換器
１１　給水管
１２　給湯端末
１３　給湯回路
１８　水量調整手段
２０　給湯負荷検知手段
２１　熱量検知手段
２２　加熱制御手段
２３　流量検知手段
２４　水温検知手段
２５　湯温検知手段
２６　温度設定手段
２７　外気温度検知手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat pump water heater.
[0002]
[Prior art]
As a conventional heat pump hot water supply device, a hot water supply device as described in Patent Document 1 has been proposed. As shown in FIG. 6, the heat pump hot water supply device in Patent Document 1 has a refrigerant circulation circuit 7 in which a compressor 2, a radiator 3, a pressure reducing means 4, and a heat absorber 5 are connected in a refrigerant flow path 1 configured as a closed circuit. A heat exchanger 10 having a water flow path 9 for exchanging heat with the refrigerant flow path a8 of the radiator 3; a water supply pipe 11 for supplying tap water to the water flow path 9; A hot water supply circuit 13 for connecting to a hot water supply terminal 12, a temperature sensor 14 provided in the hot water supply circuit 13 for detecting a hot water supply temperature, and an inverter 15 for controlling the number of revolutions of the compressor 2. The output frequency of the inverter 15 is converted according to the difference between the detected temperature and the set temperature. That is, in the conventional hot water supply apparatus, when the hot water supply temperature is lower than the set temperature, the rotation speed of the compressor 2 is increased, and when the hot water supply temperature is high, the rotation speed is controlled to decrease.
[0003]
[Patent Document 1]
JP-A-2-223767
[Problems to be solved by the invention]
However, in the configuration of the conventional hot water supply apparatus, the hot water supply load during hot water supply is not constant. In particular, since the flow rate is varied by the user depending on the purpose of hot water supply, the hot water supply load greatly changes. For example, in the case of hot water for home use, a large flow rate of 10 to 20 L / min is required when hot water is supplied to a shower or bath, but 3 to 5 L / min when washing dishes in a kitchen or supplying hot water to a wash surface. Low flow rate. The hot water supply load also changes greatly due to seasonal changes in the water supply temperature.
[0005]
The hot water supply load, which greatly changes due to such changes in the flow rate and water temperature, can be controlled by simply changing the number of rotations of the compressor and controlling the amount of hot water supplied by the heat pump as in a conventional heat pump water heater. When the hot water supply heating capacity is exceeded, hot water having a temperature lower than the target temperature is discharged, and there is a problem that the user feels uncomfortable.
[0006]
Further, in the heat pump hot water supply device as in the conventional example, it takes time for the pressure and temperature of the entire refrigerant circuit to rise at the start of hot water supply, so that the rise of the hot water temperature from the water flow path of the heat exchanger is delayed. In the conventional configuration at the start of hot water supply, the rotational speed of the compressor is simply set only by the difference between the hot water supply temperature and the set temperature, so that it takes a long time to reach the target hot water temperature in hot water supply with a large flow rate.
[0007]
As described above, in the conventional heat pump hot water supply apparatus, when the hot water supply load such as a large flow rate is large, there is a problem that the hot water cannot be supplied at the target temperature or that it takes time to reach the target temperature.
[0008]
An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a heat pump water heater in which the control of the hot water temperature is good and the hot water temperature rises quickly.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a heat pump hot water supply apparatus including a water amount adjusting unit that adjusts the amount of water in a water flow path.
[0010]
According to the present invention, since the water amount adjusting means adjusts the amount of water in the water flow path to supply hot water, even when the hot water supply load exceeds the maximum capacity as the refrigerant circuit, the water amount is adjusted to a predetermined amount by adjusting the water amount to match the capacity. It becomes possible to supply hot water at the temperature. In addition, the rise of the tapping temperature at the start of hot water supply is quickened.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The heat pump hot water supply apparatus according to the first aspect of the present invention includes a refrigerant circulation circuit including a compressor, a radiator, a pressure reducing unit, and a heat absorber, and a heat exchanger including a water flow path that performs heat exchange with the radiator. A heat pump hot water supply device having a water supply pipe for supplying tap water to the water flow path, a hot water supply circuit connected so as to pass water from the water flow path to a hot water supply terminal, and a water amount adjusting means for adjusting a water amount of the water flow path; I do.
[0012]
According to the present invention, since the amount of water flowing through the water flow path of the heat exchanger is adjusted by the water amount adjusting means, even when the hot water supply load exceeds the maximum capacity of the heat exchanger of the refrigerant circuit, the water supply load is reduced by reducing the water amount. Can be suppressed below the maximum capacity, and the predetermined temperature can be maintained without lowering the tapping temperature.
[0013]
A heat pump hot water supply apparatus according to a second aspect of the present invention is the heat pump hot water supply apparatus according to the first aspect, further comprising a hot water supply load detecting means for obtaining a hot water supply load which is a hot water supply heat quantity to the hot water supply circuit, and a heat quantity for detecting a heating amount in the heat exchanger. Detecting means, and when the value of the hot water supply load detecting means exceeds the value of the heat quantity detecting means, the water amount is reduced by the water amount adjusting means.
[0014]
According to the present invention, the hot water supply load is compared with the heating amount, and when the heating amount is insufficient for the hot water supply load, the flow rate is reduced to prevent a drop in the tapping temperature. Therefore, since the flow rate is reduced only when necessary, the flow rate does not decrease under a normal hot water supply load, and the flow rate is reduced only when, for example, the shower and the hot water supply in the kitchen overlap, or when the amount of heating is insufficient when used at a large flow rate. Therefore, the frequency of flow reduction can be minimized.
[0015]
According to a third aspect of the present invention, there is provided a heat pump hot water supply apparatus according to the second aspect, wherein a water temperature detecting means for detecting a water supply temperature of the water supply pipe, a temperature setting means for setting a target temperature of the hot water supply, and a flow rate of the hot water supply circuit are detected. The hot water supply load detecting means according to the second aspect of the present invention is configured to determine the hot water supply load from at least one of the values of the water temperature detecting means, the temperature setting means and the flow rate detecting means.
[0016]
Since the hot water supply load is proportional to a value obtained by multiplying the difference between the target temperature of the hot water supply and the water supply temperature by the flow rate, according to the present invention, the hot water supply load is calculated from the values of the water temperature detection means, the temperature setting means, and the flow rate detection means. By doing so, an accurate hot water supply load can be obtained.
[0017]
According to a fourth aspect of the present invention, there is provided a heat pump hot water supply apparatus having the configuration according to the second or third aspect, an outside air temperature detecting means for detecting an outside air temperature, a water temperature detecting means for detecting a water supply temperature of a water supply pipe, and a target of hot water supply. A temperature setting means for setting a temperature is provided, and the heat amount detection means according to claim 2 or 3 is used to determine a heating amount in the heat exchanger from at least one of the outside air temperature detection means, the water temperature detection means, and the temperature setting means. Is to ask for.
[0018]
Since the maximum heating amount in the heat exchanger of the refrigerant circuit of the present invention can be almost determined under the three conditions of the outside air temperature, the supply water temperature and the target temperature, the maximum heating amount can be accurately determined from these three points. Therefore, by comparing this value with the hot water supply load, it can be determined that the heat quantity is insufficient.
[0019]
According to a fifth aspect of the present invention, in the heat pump hot water supply apparatus, the value of the hot water supply load detecting means matches the value of the heat quantity detecting means with the amount of water reduction by the water amount adjusting means according to any one of the second to fourth aspects. In this way, the amount of water is reduced.
[0020]
According to the present invention, a target tapping temperature can be obtained with a minimum decrease in the amount of water.
[0021]
The heat pump hot water supply apparatus according to claim 6, wherein a refrigerant circulation circuit including a compressor, a radiator, a decompression unit, and a heat absorber, and a heat exchanger including a water flow path that performs heat exchange with the radiator, A water supply pipe for supplying tap water to the water flow path, a hot water supply circuit connected so as to pass water from the water flow path to a hot water supply terminal, a hot water temperature detection means for detecting a tapping temperature of the water flow path, and a hot water supply target Temperature setting means for setting the temperature; heating control means for controlling the frequency of the compressor and pressure reducing means according to the set value of the temperature setting means and the detection value of the hot water temperature detecting means; and adjusting the amount of water in the water flow path. And a water amount adjusting means for reducing the amount of water when the heating control means sets the frequency of the compressor to an upper limit.
[0022]
According to the present invention, when the frequency of the compressor reaches the upper limit, the shortage of heat exchange with respect to the hot water supply load is detected and the amount of water is reduced, so that the shortage of heat is clearly determined. It is possible to easily determine the start and end of the water amount adjustment.
[0023]
The heat pump hot water supply apparatus according to claim 7 includes a refrigerant circulation circuit including a compressor, a radiator, a pressure reducing unit, and a heat absorber, and a heat exchanger including a water flow path that performs heat exchange with the radiator. A water supply pipe for supplying tap water to the water flow path, a hot water supply circuit connected so as to pass water from the water flow path to a hot water supply terminal, a hot water temperature detection means for detecting a tapping temperature of the water flow path, and a hot water supply target Temperature setting means for setting the temperature; heating control means for controlling the frequency of the compressor and pressure reducing means according to the set value of the temperature setting means and the detection value of the hot water temperature detecting means; and adjusting the amount of water in the water flow path. Means for controlling the amount of water to be supplied, and when the tapping temperature does not reach the target temperature, the amount of water is reduced by the means for adjusting the amount of water.
[0024]
According to this invention, when the tapping temperature does not reach the target, the water amount of the water amount adjusting means is reduced, so that the tapping temperature can always be maintained near the target value.
[0025]
In the heat pump hot water supply apparatus according to an eighth aspect of the present invention, a second target value lower than the target temperature set by the temperature setting means is set in the configuration of the seventh aspect, and the hot water temperature becomes higher than a predetermined time after the start of hot water supply. If the temperature is equal to or lower than the second target temperature, the water amount is reduced by the water amount adjusting means according to the seventh aspect.
[0026]
ADVANTAGE OF THE INVENTION According to this invention, the shortage of the heat exchange with respect to a hot-water supply load can be determined clearly, and the malfunction of water amount adjustment can be prevented.
[0027]
According to a ninth aspect of the present invention, there is provided a heat pump water heater in which the amount of water is reduced by the water amount adjusting means at the start of hot water supply of the heat pump water heater according to any one of the first to eighth aspects.
[0028]
The rise time of the temperature and pressure of the refrigerant circuit at the start of hot water supply becomes longer because the amount of heat taken from the heat exchanger increases when the amount of water flowing through the water flow path is large. Therefore, the rising speed of the hot water temperature from the water flow path becomes slow, and it takes a long time to reach the target temperature. However, according to the present invention, the amount of water is reduced by the water amount adjusting means at the start of hot water supply. Or the temperature of the heat exchanger can be accelerated, and the time required for the tap water temperature to reach the target temperature can be shortened.
[0029]
According to a tenth aspect of the present invention, in the heat pump hot water supply apparatus according to the ninth aspect, when the outlet temperature of the water flow path reaches a predetermined value, the water amount adjusting unit cancels the decrease in the amount of water.
[0030]
According to the present invention, by decreasing the amount of water until the tapping temperature of the water flow path reaches the predetermined value, the rising speed of the tapping temperature is accelerated, and the drop in the quantity of water is released when the tapping temperature reaches the predetermined value. Hot water can be supplied at the original flow rate.
[0031]
A heat pump hot water supply apparatus according to an eleventh aspect of the present invention is the heat pump hot water supply apparatus according to the ninth or tenth aspect, wherein the water amount adjustment means cancels the decrease in the water amount after a predetermined time from the start of the hot water supply.
[0032]
According to the present invention, by decreasing the amount of water until a predetermined time after the start of hot water supply, the rising speed of the tapping temperature is accelerated and the decrease in the amount of water is released at the predetermined time, so that the hot water can be supplied at the original flow rate.
[0033]
A heat pump hot water supply apparatus according to a twelfth aspect of the present invention is the heat pump hot water supply apparatus according to the first aspect, wherein an upper limit is provided for the amount of water in the water flow path, and the water amount adjusting means is controlled so as not to exceed the upper limit.
[0034]
According to this invention, since the amount of water does not exceed the upper limit, there is no possibility that the amount of water is too large and the tapping temperature is lowered.
[0035]
A heat pump hot water supply apparatus according to a thirteenth aspect of the present invention sets the upper limit to the water amount according to the twelfth aspect so that the hot water supply load does not exceed the maximum heating amount in the heat exchanger.
[0036]
According to the present invention, hot water supply can be performed with the hot water supply load limited to the amount of water not exceeding the maximum heating amount, so that the hot water temperature does not drop below the target temperature.
[0037]
In a heat pump hot water supply apparatus according to a fourteenth aspect of the present invention, the refrigerant circulation circuit according to any one of the first to thirteenth aspects is a supercritical heat pump cycle in which the pressure of the refrigerant is equal to or higher than a critical pressure. The configuration is such that the flowing water in the water flow path of the heat exchanger is heated by the pressurized refrigerant.
[0038]
According to the present invention, the refrigerant flowing through the radiator of the heat exchanger is pressurized to a critical pressure or higher by the compressor. Does not condense. Therefore, it becomes easy to form a temperature difference between the refrigerant and the water in the entire region of the heat exchanger, so that high-temperature hot water can be obtained and the heat exchange efficiency can be increased.
[0039]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the conventional example and each embodiment, the same reference numerals are given to portions having the same configuration and the same operation, and detailed description will be omitted.
[0040]
(Example 1)
FIG. 1 is a configuration diagram of a heat pump hot water supply apparatus according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 7 denotes a refrigerant circulation circuit in which a compressor 2, a radiator 3, a pressure reducing means 4, and a heat sink 5 are connected to a closed circuit by a refrigerant flow path 1. The refrigerant circuit 7 uses, for example, a supercritical heat pump cycle in which carbon dioxide gas (CO2) is used as a refrigerant, and the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant. The compressor 2 is driven by a built-in electric motor (not shown), and compresses the sucked refrigerant to a pressure exceeding a critical pressure and discharges the compressed refrigerant. Reference numeral 10 denotes a heat exchanger provided with a water flow path 9 for performing heat exchange with the refrigerant flow path a8 of the radiator 3. A water supply pipe 11 for directly supplying tap water to the water flow path 9 and a hot water supply circuit 13 for passing hot water from the water flow path 9 to a hot water supply terminal 12 including a shower 16 and a faucet 17 are connected. . Reference numeral 18 denotes a water amount adjusting means for adjusting the amount of water in the water flow path 9, which is constituted by an electric throttle valve and provided in the water supply pipe 11.
[0041]
19 is a control means, a hot water supply load detecting means 20 for obtaining a hot water supply load which is a hot water supply heat quantity to the hot water supply circuit 13, a heat quantity detecting means 21 for detecting a heating amount of the water flow path 9 in the heat exchanger 10, and a compressor It has a heating control means 22 for controlling the frequency and the pressure reducing means.
[0042]
The control means 19 drives the throttle valve which is the water amount adjusting means 18 in advance by a predetermined amount to control the amount of water at the start of hot water supply to decrease, and the value of the hot water supply load detecting means 20 changes the value of the heat amount detecting means 21 When it exceeds, the water amount adjusting means 18 controls the water amount in the water flow path 9 to be reduced so that the value of the hot water supply load detecting means 20 matches the value of the heat amount detecting means 21.
[0043]
The water supply pipe 11 is provided with flow rate detection means 23 for detecting the flow rate of the hot water supply circuit 13 and water temperature detection means 24 for detecting the temperature of water supplied to the heat exchanger 10. Hot water supply circuit 13 is provided with hot water temperature detecting means 25 for detecting the temperature of hot water from water flow path 9. 26 is a temperature setting means for setting a target temperature of hot water supply, and the user arbitrarily sets the temperature. 27 is an outside air temperature detecting means for detecting the air temperature.
[0044]
The heat exchanger 10 is configured such that the flow direction of the refrigerant flow path a8 and the flow direction of the water flow path 9 are opposed to each other, and are closely adhered between the flow paths to facilitate heat transfer. With this configuration, the heat transfer between the coolant channel a8 and the water channel 9 is made uniform, and the heat exchange efficiency is improved. In addition, hot water can be supplied.
[0045]
The heating control unit 22 includes a frequency control unit 28 that changes the number of revolutions of the compressor 2 so that the deviation between the tapping temperature output by each of the hot water temperature detection unit 25 and the temperature setting unit 26 and the target temperature is reduced. The frequency of the compressor 2 is controlled by a known PID (not shown). Further, the heating control means 22 controls the opening degree of the pressure reducing means 4 so that the refrigerant discharge temperature of the compressor 2 is at a predetermined temperature and the pressure balance of the refrigerant circuit 7 becomes appropriate.
[0046]
FIG. 2 is a control flowchart of the water amount adjusting means 18 at the start of hot water supply in the first embodiment. In FIG. 2, reference numeral 30 indicates whether or not hot water is being supplied. The determination condition is that hot water is being supplied when the flow rate detecting means 23 detects the amount of water. Then, when it is determined that there is no water amount and the operation is stopped, the process proceeds to 31. Here, it is determined whether 10 minutes have elapsed since the hot water supply was stopped, and if 10 minutes have elapsed, the initial opening degree of the water amount adjusting means 18 is set to 32 at 32. If it is determined at 31 that the time is less than 10 minutes, the initial opening of 32 is not set. 10 minutes in 31 is a time for determining whether or not to reduce the amount of water when restarting hot water supply, and is set according to the cooling rate of the refrigerant circulation circuit 7 and the heat exchanger 10. A short time is set, and a long time is set if it is difficult to cool down.
[0047]
If it is determined in 30 that hot water is being supplied, the process proceeds to 34, in which it is determined whether 5 minutes have elapsed since the start of hot water supply, and if 5 minutes have elapsed, the opening of the water amount adjusting means 18 is fully opened in 35 in 100. Perform settings to return to%. Even if it is less than 5 minutes at 34, if the tapping temperature Thw exceeds the target temperature Tset-5K at 36, a setting is made at 35 to return the opening of the water amount adjusting means 18 to the full open. When the conditions of 34 and 36 do not hold, the opening of the water amount adjusting means 18 remains at the initial opening.
[0048]
Note that the initial opening degree of 32% at 32 is a level at which the amount of water can be reduced without discomfort to the user, and must be set to a value at which the rise of the tapping temperature rises quickly, and is a value to be experimentally determined in advance.
[0049]
FIG. 3 is a control flowchart of the water amount adjusting means 18 at the time of hot water supply in the first embodiment. In FIG. 3, reference numeral 40 denotes a hot water supply load calculation of the hot water supply load detecting means 20. Here, the difference between the water temperature Tw (° C.) detected by the water temperature detecting means 24 and the target temperature Tset (° C.) set by the temperature setting means 26 is multiplied by the flow rate W (L / min) detected by the flow rate detecting means 23. Then, this is multiplied by a conversion coefficient (60/860) to obtain hot water supply load Qhw (kW). Although the calculation accuracy is deteriorated, the hot water supply load may be calculated by using the water temperature as a representative fixed value or the target temperature as a fixed value. According to this, the water temperature detecting means 24 and the temperature setting means 26 become unnecessary, and can be operated even at the time of failure.
[0050]
Reference numeral 41 denotes the setting of the heating amount Qhx (kW) in the heat amount detecting means 21. That is, the heating amount Qhx is read from the heating amount table 42 based on the outside air temperature To (° C.) detected by the outside air temperature detecting means 27 and the water temperature Tw of the water temperature detecting means 24. The values in the table 42 are set in advance by experimentally obtaining the maximum heating amount under the combination of the outside air temperature and the water temperature. This table may be a mathematical expression. In addition, a table of ternary heating amounts of the outside air temperature, the water temperature, and the target temperature may be used, binary data of another two elements from the outside air temperature, the water temperature, and the target temperature may be used, The system is worse, but a one-unit table with only one element each may be used. This can reduce the amount of experimentation and the memory.
[0051]
If the condition 43 is such that the hot water supply load Qhw exceeds the heating amount Qhx, the water amount adjusting means 18 performs an opening reduction setting for decreasing the water amount by the water amount adjusting means 18. On the other hand, if the value of Qhw is smaller than the value of Qhx in 43, an increase in the opening for returning the water amount by the water amount adjusting means 18 is performed in 45. This control acts to reduce the amount of water so that the hot water supply load matches the heating amount when the hot water supply load exceeds the heating amount. The upper limit of the opening reduction is determined by 46 and 47, and the lower limit of the opening reduction is determined by 48 and 49. The lower limit value of -70% is set so that even if the throttle of the water amount adjusting means 18 advances due to an abnormality or the like, the opening degree of at least 30% is secured so that the water supply is completely closed and the hot water supply does not stop. ing.
[0052]
50 sets the opening of the water amount adjusting means 18. Here, the final opening setting X is obtained by adding the reduced opening Xd to the opening Xi at the start of hot water supply described in FIG. Then, at 51, the water amount adjusting means 18 is driven to the set opening degree.
[0053]
The operation and operation of the above configuration will be described. When the faucet 17 is opened, tap water starts flowing from the water supply pipe 11. This is detected by the flow rate detecting means 23 and a signal is sent to the control means 19 to start the compressor 2.
[0054]
At this time, since the water amount adjusting means 18 is narrowed to the initial opening, the amount of water is suppressed and the hot water is discharged. Therefore, the amount of heat exchange from the heat radiating means 3 of the refrigerant circuit 7 to the water flow path 9 is suppressed, and the temperature rise speed of the compressor 2 and the heat exchanger 10 is increased, and the temperature rise speed of the tap water temperature from the water flow passage 9 is increased. Will be faster. When the temperature of the hot water rises to (target temperature -5K) or more, the initial opening degree narrowed by the water amount adjusting means 18 is released, and the operation returns to the full opening state. At this time, since the pressure and temperature of the compressor 2 and the heat exchanger 10 are sufficiently increased, the target temperature can be reached without lowering the tapping temperature even if the amount of water is restored.
[0055]
The heating control means 22 controls the frequency of the compressor 2 based on the difference between the tapping temperature and the target temperature. Then, the high-temperature and high-pressure refrigerant gas discharged from the compressor 2 flows into the radiator 3 and heats the water flowing through the water flow path 9. Then, the heated water flows out of the hot water supply terminal 12 through the hot water supply circuit 13. On the other hand, the refrigerant cooled by the radiator 3 is decompressed by the decompression means 4 and flows into the heat absorber 5, where it absorbs natural energy such as atmospheric heat and solar heat to evaporate and return to the compressor 2. Therefore, upon detection of hot water, the high-temperature and high-pressure refrigerant gas from the compressor 1 immediately flows into the radiator 3, heats the water, and can be used as it is from the hot water supply terminal 12.
[0056]
The heating control means 22 during hot water supply calculates the frequency from the deviation between the tapping temperature and the target temperature using known PID control. That is, feedback control of the tapping temperature is performed. For the proportional gain, the integral coefficient, and the differential coefficient, which are control constants here, it is necessary to set in advance optimal values for achieving both control responsiveness and stability. The feedback control may be PI control, P control, fuzzy or neuro control.
[0057]
When hot water supply at a large flow rate such as hot water supply at two or more locations occurs during hot water supply and a hot water supply load exceeding the maximum heating amount in the heat exchanger 10 occurs, the control means 19 causes the water amount adjustment means 18 to move the water amount adjusting means 18 in the throttle direction. Since the water is driven and the amount of water is reduced until the hot water supply load substantially coincides with the maximum heating amount, the target temperature can be maintained without a significant drop in the tapping temperature.
[0058]
Further, even when the flow rate changes from the large flow rate to the normal flow rate, if the hot water supply load is lower than the maximum heating amount, the throttle in the water amount adjusting means 18 changes from a decrease in the water amount to a return to the water amount and returns to the full-open operation. Hot water supply operation is possible.
[0059]
In the first embodiment, the refrigerant circulation circuit is a supercritical refrigerant circulation circuit in which the pressure of the refrigerant is equal to or higher than the critical pressure.
[0060]
(Example 2)
FIG. 4 is a control flowchart of the water amount adjusting means 18 at the time of hot water supply of the heat pump hot water supply apparatus according to the second embodiment of the present invention. The same components as those of the hot water supply device of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 4, the difference from the configuration of the first embodiment is that the control of the water amount adjusting means 18 is performed by the set value of the water amount upper limit of 55. In 55, the upper limit WL (L / min) of the water amount is calculated from the maximum heating amount Qhx (kW) obtained in 41, the target temperature Tset (° C), and the water temperature Tw (° C). Then, it is determined in step 56 whether the water amount W (L / min) detected by the flow rate detecting means 23 does not exceed the upper limit WL of the water amount. Perform reduction settings. On the other hand, if it does not exceed, at 45, an opening increase setting for returning the water amount by the water amount adjusting means 18 is performed.
[0061]
As described above, in the second embodiment, the upper limit of the amount of water is set from the maximum amount of heating, and control is performed so that the detected value of the amount of water does not exceed the upper limit.
[0062]
(Example 3)
FIG. 5 is a control flowchart of the water amount adjusting means 18 at the time of hot water supply of the heat pump hot water supply apparatus according to the third embodiment of the present invention. The same components as those of the hot water supply device of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 5, the point different from the configuration of the first embodiment is that a second target value 5 K lower than the target temperature set by the temperature setting means 26 is set, and the tapping temperature becomes three minutes after the start of hot water supply. And when the heating control means 22 sets the frequency of the compressor 2 to the upper limit, the amount of water is reduced. Specifically, the following control is performed.
[0063]
At 60, the frequency of the compressor 2 of the heating control means 22 is set. That is, the frequency F is calculated from the deviation between the tapping temperature Thw and the target temperature Tset using the known PID control.
[0064]
61 judges whether three minutes have passed since the start of hot water supply. If it is less than 3 minutes, in 62, the opening degree reduction setting of the water flow reduction is set to 0%, and the water flow reduction is prohibited. If it is determined at 61 that three minutes or more have elapsed, the routine proceeds to 63.
[0065]
If the control frequency F of the compressor 2 is equal to or higher than the upper limit value Fmax and the tapping temperature Thw is lower than the target temperature Tset−3K, the water amount adjusting means 18 performs an opening degree reduction setting by the water amount adjusting means 18 at 44. On the other hand, if the condition of 63 is not satisfied, an increase in the opening for returning the water amount by the water amount adjusting means 18 is performed at 45.
[0066]
Three minutes from the start of hot water supply at 61 sets the capacity of the entire system and the time until the temperature rises, and this value varies depending on system conditions.
[0067]
The determination at 63 determines whether the maximum heating amount has been reached based on the frequency F and whether the capacity is insufficient based on the tapping temperature Thw. Then, both of them determine that the maximum heating amount has been reached and the capacity is insufficient. In the third embodiment, the determination accuracy is improved by performing the determination based on both the state of the frequency F and the tapping temperature Thw. However, even if each determination is performed independently, the capability shortage can be determined with sufficient accuracy.
[0068]
In the above-described first to third embodiments, a complete instantaneous hot water supply device having no hot water storage tank or heat storage material has been described. However, if the hot water heated by the heat pump is directly supplied to the hot water supply terminal, The same effect can be obtained by having a hot water storage tank in parallel with the heat exchanger, or having a hot water storage tank in series with the heat exchanger, or even having a heat storage material in the water side circuit or refrigerant circuit. can get.
[0069]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a heat pump hot water supply apparatus with good responsiveness and stability of hot water supply control.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a heat pump hot water supply apparatus according to a first embodiment of the present invention. FIG. 2 is a control flowchart of a water amount adjusting unit at the start of hot water supply according to the first embodiment of the present invention. FIG. 4 is a control flowchart of a water amount adjusting means at the time of hot water supply according to the second embodiment of the present invention. FIG. 5 is a control flowchart of a water amount adjusting means at the time of hot water supply according to the third embodiment of the present invention. 6: Configuration of conventional heat pump hot water supply system
2 Compressor 3 Radiator 4 Decompression means 5 Heat sink 7 Refrigerant circulation circuit 9 Water flow path 10 Heat exchanger 11 Water supply pipe 12 Hot water supply terminal 13 Hot water supply circuit 18 Water quantity adjustment means 20 Hot water supply load detection means 21 Heat quantity detection means 22 Heat control means 23 Flow rate detecting means 24 Water temperature detecting means 25 Hot water temperature detecting means 26 Temperature setting means 27 Outside air temperature detecting means

Claims

A refrigerant circulation circuit including a compressor, a radiator, a pressure reducing unit, and a heat absorber, a heat exchanger including a water flow path that performs heat exchange with the radiator, and a water supply pipe that supplies tap water to the water flow path. A heat pump hot water supply apparatus comprising: a hot water supply circuit connected so as to allow water to flow from the water flow path to the hot water supply terminal; and a water amount adjusting means for adjusting the amount of water in the water flow path.

Hot water supply load detection means for obtaining a hot water supply load that is the amount of hot water supplied to the hot water supply circuit, and heat quantity detection means for detecting the amount of heat in the heat exchanger are provided, and the value of the hot water supply load detection means corresponds to the value of the heat quantity detection means. The heat pump water heater according to claim 1, wherein the amount of water is reduced by the water amount adjusting means when the amount exceeds the amount.

Water temperature detecting means for detecting a water temperature of a water supply pipe, temperature setting means for setting a target temperature of hot water supply, and flow rate detecting means for detecting a flow rate of a hot water circuit are provided. The heat pump hot water supply apparatus according to claim 2, wherein the hot water supply load is obtained from at least one of the values of the setting means and the flow rate detection means.

An outside air temperature detecting means for detecting an outside air temperature, a water temperature detecting means for detecting a water supply temperature of a water supply pipe, and a temperature setting means for setting a target temperature of hot water supply are provided, and the calorie detecting means includes the outside air temperature detecting means and the water temperature detecting means. The heat pump hot water supply apparatus according to claim 2 or 3, wherein a heating amount in the heat exchanger is obtained from at least one of the values of the means and the temperature setting means.

The heat pump water heater according to any one of claims 2 to 4, wherein the amount of water decrease by the water amount adjuster decreases the amount of water so that the value of the hot water supply load detector matches the value of the heat amount detector.

A refrigerant circulation circuit including a compressor, a radiator, a pressure reducing unit, and a heat absorber, a heat exchanger including a water flow path that performs heat exchange with the radiator, and a water supply pipe that supplies tap water to the water flow path. A hot water supply circuit connected to allow water to flow from the water flow path to the hot water supply terminal, a hot water temperature detection means for detecting a hot water temperature of the water flow path, a temperature setting means for setting a target temperature of the hot water supply, and the temperature setting means Heating control means for controlling the frequency and decompression means of the compressor in accordance with the set value and the detection value of the hot water temperature detection means, and water amount adjustment means for adjusting the amount of water in the water flow path, wherein the heating control means A heat pump water heater that reduces the amount of water by the water amount adjusting means when the frequency of the compressor is set to an upper limit.

A refrigerant circulation circuit including a compressor, a radiator, a pressure reducing unit, and a heat absorber, a heat exchanger including a water flow path that performs heat exchange with the radiator, and a water supply pipe that supplies tap water to the water flow path. A hot water supply circuit connected to allow water to flow from the water flow path to the hot water supply terminal, a hot water temperature detection means for detecting a hot water temperature of the water flow path, a temperature setting means for setting a target temperature of the hot water supply, and the temperature setting means Heating control means for controlling the frequency of the compressor and the pressure reducing means in accordance with the set value of the temperature and the detection value of the hot water temperature detecting means, and water amount adjusting means for adjusting the amount of water in the water flow path, wherein the tapping temperature is set to the target A heat pump water heater that reduces the amount of water by the water amount adjusting means when the temperature does not reach.

8. The water supply system according to claim 7, wherein a second target value lower than the target temperature set by the temperature setting means is set, and after a predetermined time from the start of hot water supply, if the tap water temperature is equal to or lower than the second target temperature, the water amount is reduced. Heat pump water heater.

The heat pump hot water supply apparatus according to any one of claims 1 to 8, wherein the amount of water is reduced by a water amount adjusting means at the start of hot water supply.

The heat pump hot water supply apparatus according to claim 9, wherein when the tapping temperature of the water flow path reaches a predetermined value, the decrease in the water amount by the water amount adjusting means is canceled.

The heat pump hot water supply apparatus according to claim 9 or 10, wherein a predetermined amount of time after the start of hot water supply, the decrease in the amount of water by the water amount adjusting means is released.

The heat pump hot water supply apparatus according to claim 1, wherein an upper limit is set for the amount of water in the water flow path, and the water amount adjusting unit is controlled so as not to exceed the upper limit.

The heat pump hot water supply apparatus according to claim 12, wherein the upper limit of the water amount is determined so that the hot water supply load does not exceed the maximum heating amount in the heat exchanger.

The refrigerant circulation circuit is a supercritical heat pump cycle in which the pressure of the refrigerant is equal to or higher than the critical pressure, and heats the flowing water in the water flow path of the heat exchanger with the refrigerant pressurized to the critical pressure or higher. The hot water supply device according to claim 1.