JP4030394B2

JP4030394B2 - Hot water storage water heater

Info

Publication number: JP4030394B2
Application number: JP2002266760A
Authority: JP
Inventors: 誠本間
Original assignee: Corona Corp
Current assignee: Corona Corp
Priority date: 2002-09-12
Filing date: 2002-09-12
Publication date: 2008-01-09
Anticipated expiration: 2022-09-12
Also published as: JP2004101134A

Description

【０００１】
【発明の属する技術分野】
本発明は貯湯タンク内の湯水を熱源とする熱交換器を備えた貯湯式給湯装置に関するものである。
【０００２】
【従来の技術】
従来よりこの種の貯湯式給湯装置では、本願出願人が先に出願した特願２００２−３９４７８号で開示した貯湯タンク内に貯湯された高温水を熱源として風呂の追焚きや暖房に用いるようにしたものがあった。
【０００３】
この従来のものを図７に基づいて説明すると、１０１は加熱手段としてのヒートポンプ回路、１０２は貯湯タンクで、この貯湯タンク１０２下部から取り出した低温水をヒートポンプ回路１０１で高温に加熱して貯湯タンク１０２の上部から積層貯湯していくものである。
【０００４】
前記貯湯タンク１０２には、その下端に給水管１０３が接続され、また上端には出湯管１０４が接続されているものである。１０５は電動ミキシング弁で、出湯管１０４からの高温水と給水管１０３からの低温水をリモコン（図示せず）等で設定された任意の給湯設定温度に混合して給湯栓１０６から出湯するものである。
【０００５】
１０７は暖房あるいは風呂の追焚きあるいは保温の熱源としての熱交換器で、出湯管１０４から分岐した熱交往き管１０８および給水管１０３に合流する熱交戻り管１０９により貯湯タンク１０２と循環可能に接続されており、貯湯タンク１０２内の高温水を熱交換器１０７に流入させて暖房回路、風呂の追焚き回路あるいは保温回路等の２次側回路（図示せず）の温水を加熱するものである。
【０００６】
そして、貯湯タンク１０２の上部から取り出された高温水は、前記熱交換器１０７で熱交換されて温度低下して中温水となって貯湯タンク１０２の下部から貯湯タンク１０２内に戻るものである。
【０００７】
なお、このような従来の貯湯式給湯装置にかかる公知の刊行物を本願出願人は発見することができないが、貯湯タンク内に貯湯された高温水を熱源として暖房を行うものとして例えば特許文献１が挙げられる。
【０００８】
【特許文献１】
特許第２６６３６３７号公報（図１）
【０００９】
【発明が解決しようとする課題】
しかし、この従来のものでは、熱交換器１０７での熱交換により中温水が貯湯タンク１０２に貯まっていくが、この中温水は暖房あるいは追焚きの熱源として利用するには温度が低いため適さず、しかも湯切れするまで給湯を行わないと容量当たりの保有熱量が少ない中温水がいつまでも貯湯タンク１０２内に残留し、貯湯タンク１０２の保有熱量を減らしてしまい貯湯タンク容量の有効利用ができないという課題があった。
【００１０】
【課題を解決するための手段】
そこで、本発明はこれらの課題を解決するために、請求項１では、給水管と出湯管との間に並列に設けられ、湯水を貯湯する第１および第２の貯湯タンクと、前記第１および第２貯湯タンク内の湯水を高温に加熱する加熱手段と、前記第１、第２貯湯タンクの出湯側の合流点あるいは給水側の分岐点に設けられ、前記第１、第２貯湯タンクからの出湯比率を調整可能な混合弁と、熱交換器と熱交循環ポンプを備え前記第１貯湯タンクの上部と前記第２貯湯タンクの上部を連通し、且つ前記第１貯湯タンク下部と前記第２貯湯タンク下部を連通し、前記第２貯湯タンク上部から取り出した高温水を前記熱交換器で放熱させ、生成された中温水を前記第１貯湯タンク上部に戻すようにした熱交循環回路とを備え、給湯時は前記第１貯湯タンクの高温水あるいは中温水を前記第２貯湯タンクの高温水よりも優先して使用するように前記混合弁の開度を調整するようにし、更に前記加熱手段を二酸化炭素冷媒を用いたヒートポンプ回路として超臨界ヒートポンプサイクルを構成すると共に、前記第１および第２貯湯タンクと前記ヒートポンプ回路とをヒーポン循環回路にて並列かつ湯水が循環可能に接続し、前記第１および第２の貯湯タンク下部からの湯水を前記ヒートポンプ回路で加熱して前記第１および第２の貯湯タンク上部へ戻すよう構成した。
【００１１】
これにより、加熱手段により第１および第２の貯湯タンク内の湯水が高温に沸き上げられ、混合弁によって第１貯湯タンク側の開度が全開あるいは第２貯湯タンク側よりも大きく開かれ、第１貯湯タンクに貯められた高温水が第２貯湯タンクよりも優先して給湯に使用される。そして、貯湯タンク内の高温水を熱源として二次側を加熱するときは、熱交循環ポンプの駆動により第２貯湯タンク上部から取り出した高温水を熱交循環回路を介して熱交換器に循環させ、二次側との熱交換により生成された中温水を第１貯湯タンク上部に戻すようにしている。そして、第１貯湯タンクに高温水あるいは中温水がある間は、混合弁の開度を調整して第１貯湯タンク内の高温水あるいは中温水を第２貯湯タンクの高温水よりも先に優先して給湯に使用されるものである。このとき、もしも中温水の温度が給湯に利用できない温度まで低下したとしても、混合弁の開度の調整によりこの中温水を第２貯湯タンクの高温水と混合して給湯に有効に利用可能な温度まで昇温して中温水を優先的に給湯に用いるものである。しかも、給湯に利用可能な中温水があるにもかかわらず第２貯湯タンクの高温水をムダに給湯してしまうことがなく、熱源としての能力を確保できる。
又ヒートポンプ回路に対して並列に設けられた第１および第２の貯湯タンクの下部には給湯の使用によって低温水が流入するものであり、この低温水をヒーポン循環回路を介して循環して二酸化炭素冷媒を用いた超臨界ヒートポンプサイクルのヒートポンプ回路で加熱するので、高効率で高温の沸き上げが可能となるものである。
【００１２】
また、請求項２では、給水管と出湯管との間に並列に設けられ、湯水を貯湯する第１および第２の貯湯タンクと、前記第１および第２貯湯タンク内の湯水を高温に加熱する加熱手段と、前記第１、第２貯湯タンクの出湯側の合流点あるいは給水側の分岐点に設けられ、前記第１または第２貯湯タンクの一方から出湯させるよう流路を切換える出湯切換弁と、熱交換器と熱交循環ポンプを備え前記第１貯湯タンクの上部と前記第２貯湯タンクの上部を連通し、且つ前記第１貯湯タンク下部と前記第２貯湯タンク下部を連通し、前記第２貯湯タンク上部から取り出した高温水を前記熱交換器で放熱させ、生成された中温水を前記第１貯湯タンク上部に戻すようにした熱交循環回路とを備え、給湯時は前記第１貯湯タンクの高温水あるいは中温水を前記第２貯湯タンクの高温水よりも優先して使用するように前記出湯切換弁を切換えるようにし、更に前記加熱手段を二酸化炭素冷媒を用いたヒートポンプ回路として超臨界ヒートポンプサイクルを構成すると共に、前記第１および第２貯湯タンクと前記ヒートポンプ回路とをヒーポン循環回路にて並列かつ湯水が循環可能に接続し、前記第１および第２の貯湯タンク下部からの湯水を前記ヒートポンプ回路で加熱して前記第１および第２の貯湯タンク上部へ戻すよう構成した。
【００１３】
これにより、これにより、加熱手段により第１および第２の貯湯タンク内の湯水が高温に沸き上げられ、出湯切換弁によって第１貯湯タンク側を選択し、第１貯湯タンクに貯められた高温水が第２貯湯タンクよりも優先して給湯に使用される。そして、貯湯タンク内の高温水を熱源として二次側を加熱するときは、熱交循環ポンプの駆動により第２貯湯タンク上部から取り出した高温水を熱交循環回路を介して熱交換器に循環させ、二次側との熱交換により生成された中温水を第１貯湯タンク上部に戻すようにしている。そして、第１貯湯タンクに高温水あるいは中温水があるときは、出湯切換弁を第１貯湯タンク側に切換えて第１貯湯タンク内の高温水あるいは中温水を第２貯湯タンクの高温水よりも先に優先して給湯に使用されるものである。しかも、給湯に利用可能な中温水があるにもかかわらず第２貯湯タンクの高温水をムダに給湯してしまうことがなく、熱源としての能力を確保できる。
又ヒートポンプ回路に対して並列に設けられた第１および第２の貯湯タンクの下部には給湯の使用によって低温水が流入するものであり、この低温水をヒーポン循環回路を介して循環して二酸化炭素冷媒を用いた超臨界ヒートポンプサイクルのヒートポンプ回路で加熱するので、高効率で高温の沸き上げが可能となるものである。
【００１４】
また、請求項３では、前記給水管から前記第１、第２の貯湯タンクをバイパスして前記出湯管に合流するバイパス管を設け、前記バイパス管と前記出湯管の合流点あるいは前記バイパス管と前記給水管の分岐点に、前記バイパス管および前記出湯管を流れる湯水の混合比率を調節して給湯管へ流出させる温調ミキシング弁を設けた。
【００１５】
これにより、貯湯タンクから出湯されてくる湯が高温あるいは中温であったとしても温調ミキシング弁によって給水管からの低温水と混合して任意の給湯温度で給湯を行うことができる。
【００１８】
また、請求項４では、前記ヒーポン循環回路途中に、このヒーポン循環回路を前記第１貯湯タンクあるいは第２貯湯タンクの一方に選択的に連通させて加熱する貯湯タンクを選択する加熱切換弁を設けた。
【００１９】
これにより、ヒートポンプ回路に対して並列に設けた第１および第２の貯湯タンクのどちらを加熱するかを切換える加熱切換弁を設けることによって、一方の貯湯タンクを選択して沸き上げることができ、第１および第２の貯湯タンクのそれぞれの上部に高温水および中温水が残っている場合などにおいて、各貯湯タンクの下部に貯められている低温水だけを選択して沸き上げることが可能となると共に、各貯湯タンクへの配管の流通抵抗の差によって一方の貯湯タンクへ偏って沸き上げられてしまうなどの不都合がないものである。
【００２０】
また、請求項５では、前記ヒートポンプ回路による湯水の沸き上げ動作時において、前記ヒートポンプ回路の出力が安定するまでは、前記加熱切換弁が前記第１貯湯タンク側に切換えられているようにした。
【００２１】
これにより、沸き上げ動作時にヒートポンプ回路の出力が安定するまでに生成される中温水は、加熱切換弁が第１貯湯タンク側に切換えられていることによって第１貯湯タンクに貯められ、その後の給湯時に第１貯湯タンクの湯水が第２貯湯タンクよりも優先して給湯に使用されることとなり、この中温水も全て使い切ることが可能となって沸き上げ初期に消費したエネルギーも無駄にすることなく有効に利用することができるものである。
【００２２】
また、請求項６では、前記熱交循環ポンプ作動中での前記ヒートポンプ回路による湯水の沸き上げ動作時においては、前記加熱切換弁が前記第２貯湯タンク側へ切換えられ、第２貯湯タンク側の湯水を沸き上げるようにした。
【００２３】
これにより、熱交循環ポンプが作動している二次側との熱交換中の間に第２貯湯タンク内の高温水が足りなくなるなどして沸き増しが必要になった場合では、加熱切換弁を第２貯湯タンク側に切換えて、第２貯湯タンクの下部から取り出した低温水を沸き上げて同第２貯湯タンクの上部に戻し、熱源となる高温水の供給源となる第２貯湯タンクに貯めるようにすることで、沸き上げられた熱交換効率の高い高温水を直ぐに熱源として用い、そして熱交換により生成された中温水を第１貯湯タンクを介して給湯することができ、効率的に湯水の熱を分配できて熱の使用効率がよいものである。
【００２４】
【発明の実施の形態】
次に、本発明の一実施形態の貯湯式給湯装置を図面に基づいて説明する。なお、図２〜図５中の貯湯タンク２にハッチングした斜線は低温水、二重斜線は中温水、三重斜線は高温水を示し、矢印は湯水の流れ方向を示すものである。
【００２５】
この貯湯式給湯装置は、時間帯別契約電力の電力単価が安価な深夜時間帯に湯水を沸き上げて貯湯し、この貯湯した湯水を給湯に用いるもので、１は温水を貯湯する貯湯タンク２を備えた貯湯タンクユニット、３は貯湯タンク内の湯水を加熱するヒートポンプユニット、４は台所や浴室等に設けられた給湯栓、５は浴槽である。
【００２６】
前記貯湯タンクユニット１には、給水管６と出湯管７との間に、湯水を貯湯する第１貯湯タンク２Ａおよび第２貯湯タンク２Ｂが並列に設けられており、第１貯湯タンク２Ａ下部に第１給水管６Ａ、上部に第１出湯管７Ａが、第２貯湯タンク２Ｂ下部に第２給水管６Ｂ、上部に第２出湯管７Ｂがそれぞれ接続され、前記第１出湯管７Ａと第２出湯管７Ｂとの合流点には、前記第１貯湯タンク２Ａまたは第２貯湯タンク２Ｂからの出湯比率を調整可能な混合弁８が設けられると共に、この混合弁８の下流側に混合された出湯温度を検出する出湯温度センサ９が設けられているものである。なお、この混合弁８は前記第１給水管６Ａと第２給水管６Ｂの分岐点に設けても良く、この場合では出湯温度センサ９は混合弁８の下流側ではなく、前記第１給水管６Ａと第２給水管６Ｂの合流点の下流側に設けることで混合された出湯温度を検出して混合弁８の混合比率を適切に調整可能とすることができる。
【００２７】
１０は前記給水管６から前記第１貯湯タンク２Ａおよび第２貯湯タンク２Ｂをバイパスして前記出湯管７に合流するバイパス管で、このバイパス管１０と前記出湯管６の合流点に設けられたバイパス管１０および出湯管７を流れる湯水の混合比を調節してリモコン（図示せず）等で設定される任意の給湯設定温度の湯を給湯栓４に接続された給湯管１１に流出させる温調ミキシング弁１２を介して連通されているものである。
【００２８】
１３は前記温調ミキシング弁１２の出口側の給湯管１１に設けられこの給湯管１１から給湯される湯水の温度を検出する給湯温度センサで、検出された温度に応じて前記温調ミキシング弁１２の混合比率の調節が行われるものである。１４は給湯管１１に設けられ給湯流量をカウントする給湯流量カウンタである。１５は給水管６に設けられ給水圧を減圧する減圧弁である。１６は前記減圧弁１５よりも下流側の給水管６に設けられ給水の温度を検出する給水温度センサである。
【００２９】
前記第１貯湯タンク２Ａおよび第２貯湯タンク２Ｂには垂直方向にそれぞれ複数個の貯湯温度センサ１７Ａおよび１７Ｂが設けられており、各貯湯タンク２Ａ、２Ｂに貯湯されている湯水の温度を検出して各貯湯タンク２Ａ、２Ｂ内の残り湯量および垂直方向の温度分布を概略検知するものである。
【００３０】
次に、前記ヒートポンプユニット３は、圧縮機１８と凝縮器としての冷媒−水熱交換器１９と電子膨張弁２０と蒸発器としての空気熱交換器２１で構成された加熱手段としてのヒートポンプ回路２２と、各貯湯タンク２Ａ、２Ｂ内の被加熱水たる湯水をヒーポン循環回路２３を介して冷媒−水熱交換器１９に循環させるヒーポン循環ポンプ２４とを備えており、ヒートポンプ回路２２の冷媒回路内には冷媒として二酸化炭素が充填されて超臨界ヒートポンプサイクルを構成しているものである。なお、冷媒に二酸化炭素を用いているので、低温水を電熱ヒータなしで約９０℃の高温まで沸き上げることが可能なものである。
【００３１】
ここで、前記冷媒−水熱交換器１９は冷媒と被加熱水たる湯水とが対向して流れる対向流方式を採用しており、超臨界ヒートポンプサイクルでは熱交換時において冷媒は超臨界状態のまま凝縮されるため効率良く高温まで被加熱水を加熱することができ、被加熱水の冷媒−水熱交換器１９入口温度と冷媒の出口温度との温度差ΔＴが一定になるように前記電子膨張弁２０または圧縮機１８を制御することで、被加熱水の冷媒−水熱交換器１９の入口温度が１５℃程度の温度であるとＣＯＰ（エネルギー消費効率）が３．０以上の高効率での加熱を行うことが可能なものである。
【００３２】
そして、前記貯湯タンクユニット１側の前記ヒーポン循環回路２３のヒーポン往き管２５とヒーポン戻り管２６との間に、第１貯湯タンク２Ａおよび第２貯湯タンク２Ｂが並列に設けられており、第１貯湯タンク２Ａ下部に第１ヒーポン往き管２５Ａ、上部に第１ヒーポン戻り管２６Ａが、第２貯湯タンク２Ｂ下部に第２ヒーポン往き管２５Ｂ、上部に第２ヒーポン戻り管２６Ｂがそれぞれ接続され、前記第１ヒーポン戻り管２６Ａと第２ヒーポン戻り管２６Ｂの分岐点には、第１貯湯タンク２Ａまたは第２貯湯タンク２Ｂの一方を選択的に前記冷媒−水熱交換器１９の水側と連通させる三方弁より成る加熱切換弁２７が設けられているものである。なお、この加熱切換弁２７は第１ヒーポン往き管２５Ａと第２ヒーポン往き管２５Ｂとの合流点に設けても良く、また、第１ヒーポン戻り管２６Ａと第２ヒーポン戻り管２６Ｂあるいは第１ヒーポン往き管２５Ａと第２ヒーポン往き管２５Ｂにそれぞれ設けた開閉弁により構成しても良いものである。
【００３３】
次に、２８は浴槽５内の湯水を加熱するための熱交換器、２９はこの熱交換器２８の一次側に熱源となる貯湯タンク２内の高温水を循環させる熱交循環ポンプ、３０は上流側から第２貯湯タンク２Ｂ上部、熱交換器２８、熱交循環ポンプ２９、第１貯湯タンク２Ａ上部を順に連通すると共に、第１貯湯タンク２Ａ下部と第２貯湯タンク２Ｂ下部とを連通する熱交循環回路で、第２貯湯タンク２Ｂ上部から取り出した高温水を熱交換器２８に流入させ、浴槽水と熱交換して生成される中温水を第１貯湯タンク２Ａ上部に戻すようにしているものである。
【００３４】
ここで、熱交循環回路３０の第１貯湯タンク２Ａ下部と第２貯湯タンク２Ｂ下部とを連通する側は、前記ヒーポン循環回路２４の第１ヒーポン往き管２５Ａと第２ヒーポン往き管２５Ｂとで兼用されているもので、ヒーポン循環回路２４の一部と兼用することで配管の本数および各貯湯タンク２Ａ、２Ｂへの接続部の数を少なくすることができコストダウンを計っているものである。なお、熱交循環回路３０の第１貯湯タンク２Ａ下部と第２貯湯タンク２Ｂ下部とを連通する側は、第１給水管６Ａと第２給水管６Ｂとで兼用するようにしても良いし、また専用の配管を設けても良いものである。
【００３５】
また、前記熱交換器２８の二次側には浴槽５内の湯水を循環可能に接続する風呂循環回路３１が接続され、浴槽５内の湯水を風呂循環ポンプ３２で熱交換器２８へ循環させるようにし、第２貯湯タンク２Ｂからの高温水を熱源として浴槽水の追焚きあるいは保温を行うようにしているものである。
【００３６】
そして、前記風呂循環回路３１には前記給湯管１１から分岐した湯張り管３３が接続されており、この湯張り管３３に設けられた湯張り弁３４を開弁して浴槽５への所定水量または所定水位の湯張りを行うものである。
【００３７】
３５はこの貯湯式給湯装置の各センサの検出値あるいはリモコン（図示せず）からの指令が入力され、予め記憶されているプログラムに従って各アクチュエータを駆動制御する制御手段である。
【００３８】
ここで、深夜時間帯になって貯湯タンク２内の湯水を沸き上げる際の動作について説明すると、前記制御手段３５により前記ヒートポンプユニット３の圧縮機１８が作動されると共に、加熱切換弁２７が第１貯湯タンク２Ａ側に切換えられ、第１貯湯タンク２Ａ内に満たされている水を下部の第１ヒーポン往き管２４Ａを介してヒーポン循環ポンプ２４によりヒートポンプユニット３の冷媒−水熱交換器１９へ流入させて加熱し、加熱された高温水は第１ヒーポン戻り管２５Ａを流れて第１貯湯タンク２Ａの上部から戻されて積層状に貯湯される。
【００３９】
そして、第１貯湯タンク２Ａが沸き上げられたことを貯湯温度センサ１７Ａで検出すると、前記加熱切換弁２７が第２貯湯タンク２Ｂ側に切換えられ、第２貯湯タンク２Ｂ内に満たされている水を下部の第２ヒーポン往き管２５Ｂを介して第１貯湯タンク２Ａの沸き上げと同じくヒートポンプユニット３にて沸き上げるものである。
【００４０】
このように、一方の貯湯タンク２を先に沸き上げるようにしているので、簡単に貯湯タンク２内の湯水を必要な量だけ管理しながら沸き上げることができ、第１ヒーポン往き管２５Ａと第２ヒーポン往き管２５Ｂ、あるいは第１ヒーポン戻り管２６Ａと第２ヒーポン戻り管２６Ｂとの間の流通抵抗の微差によって意図しない一方の貯湯タンク２に偏って沸き上げられてしまうなど不都合がない。そして、必要な量が沸き上げられると第１貯湯タンク２Ａの湯水を第２貯湯タンク２Ｂの湯水よりも優先的に使用するため前記第１出湯管７Ａと第２出湯管７Ｂとの合流点に設けられている混合弁８が第１貯湯タンク２Ａ側の開度を全開にされて給湯が開始されるのを待機する。
【００４１】
なお、ここでは第１貯湯タンク２Ａを先に沸き上げる構成について説明したが、先に第２貯湯タンク２Ｂを沸き上げてから第１貯湯タンク２Ａを沸き上げるようにしても良いし、前記加熱切換弁２７を第１貯湯タンク２Ａと第２貯湯タンク２Ｂの中間位置に切換えて両方を一度に沸き上げるようにすることを妨げるものではない。
【００４２】
そして、貯湯タンク２が沸き上げられている状態で給湯あるいは浴槽５への湯張りを行う場合は、図２に示すように、給湯栓４あるいは湯張り弁３４が開かれると、前記制御手段３５によって前記混合弁８が第１貯湯タンク２Ａ側の開度を全開にされているので、給水管６からの給水は第１給水管６Ａを流れて第１貯湯タンク２Ａへ下部から流入し、上部の第１出湯管７Ａから高温水が出湯管７に流出する。そして、前記温調ミキシング弁１２にてバイパス管１０からの水と混合されてリモコン等によって設定される給湯設定温度あるいは風呂設定温度に調整されて給湯管１１を流れて給湯栓４から給湯され、あるいは湯張り管３３を流れ、風呂循環回路３１を介して浴槽５に湯張りされるものである。
【００４３】
このとき、前記混合弁８の第２貯湯タンク２Ｂ側の開度が全閉とされて流路が閉じられているので、この第２貯湯タンク２Ｂ内に低温水が流入することはなく、高温水が貯湯された状態を継続し、前記第１貯湯タンク２Ａの下部には流出した高温水と同じ量だけの低温水が貯湯されるものである。ここで、第１貯湯タンク２Ａには上部に高温水、下部に低温水が貯められているが、その温度差により比重差が発生し、温度境界層を形成して比重の軽い高温水が上部に、比重の重い低温水が下部に位置するので、互いに混じり合うことはないものである。
【００４４】
そして、給湯栓４が閉じられるかあるいは給湯流量カウンタ１４がリモコン等によって設定される湯張り量をカウントするかまたは風呂循環回路３１途中に設けられた水位センサ（図示せず）が所定の水位を検出して湯張り弁３４が閉じられると、給湯あるいは湯張りが停止する。
【００４５】
ここで、第１貯湯タンク２Ａの貯湯量が少ないか給湯量あるいは湯張り量が多く、第１貯湯タンク２Ａ内の高温水を使い切ってしまい第１貯湯タンク２Ａの側面に設けられた貯湯温度センサ１７Ａの最上部のセンサが所定温度以下の低温水を検出したら、前記制御手段３５により前記混合弁８が第２貯湯タンク２Ｂ側の開度を全開にして、第２貯湯タンク２Ｂに貯められた高温水を用いて給湯あるいは湯張りを行うものである。
【００４６】
次に、浴槽５に湯張りされた湯を保温あるいは追焚きする場合は、図３に示すように、前記制御手段３５が風呂循環ポンプ３２を駆動して浴槽５内の湯を熱交換器２８へ循環させると共に、熱交循環ポンプ２９を駆動して第２貯湯タンク２Ｂの上部に貯められている高温水を熱交循環回路３０を介して熱交換器２８へ循環させ、浴槽５内の湯水と第２貯湯タンク２Ｂに貯湯されていた高温水とを熱交換させて保温あるいは追焚きを行う。
【００４７】
そして、第２貯湯タンク２Ｂから熱交換器２８に流入した高温水は浴槽水との熱交換により温度低下し、生成された中温水は熱交循環ポンプ２９の作動によって第１貯湯タンク２Ａの上部に戻されると同時に、第１貯湯タンク２Ａの下部の給湯または湯張りによって流入していた低温水が熱交循環回路３０の一部を構成するヒーポン循環回路２４の第１ヒーポン往き管２５Ａと第２ヒーポン往き管２５Ｂを介して第２貯湯タンク２Ｂの下部に流入するようにして熱源となる温水を循環させるようにしているものである。ここで、第２貯湯タンク２Ｂには、上部に高温水、下部に低温水が貯められることになるが、その温度差により比重差が発生し、温度境界層を形成して比重の軽い高温水が上部に、比重の重い低温水が下部に位置するので、互いに混じり合うことはないものである。
【００４８】
また、第１貯湯タンク２Ａの上部に流れ込んだ中温水は、第１貯湯タンク２Ａの上部に高温水が残っている場合はこの高温水と混合され、また、第１貯湯タンク２Ａの高温水を全部使い切った後は中温水のままで第１貯湯タンク２Ａの上部に貯められることとなる。この場合でも、上部の中温水と下部の低温水との間の温度差により比重差が発生し、温度境界層を形成して互いに混じり合うことがないものである。このように、熱交換により生成された中温水は給湯に有効に利用できる温度のままで全て第１貯湯タンク２Ａに貯められることとなるものである。
【００４９】
次に、第１貯湯タンク２Ａに中温水が貯められている状態で給湯する場合は、図４に示すように、給湯栓４が開かれると、前記制御手段３５によって前記混合弁８が第１貯湯タンク２Ａ側の開度を全開にされているので、給湯の開始によって第１給水管６Ａからの低温水が第１貯湯タンク２Ａの下部に流入し、第１貯湯タンク２Ａの上部に貯められている中温水が第１出湯管７Ａから出湯する。そして、前記温調ミキシング弁１２にてバイパス管１０からの低温水と混合されて給湯設定温度に調整されて給湯されるものである。
【００５０】
ここで、もしも給湯設定温度が高温に設定され第１貯湯タンク２Ａに貯められている中温水が給湯に利用できない温度である場合は、前記出湯温度センサ９の検出温度に基づいて前記混合弁８の混合比率を調整し、第１貯湯タンク２Ａからの中温水と第２貯湯タンク２Ｂからの高温水を給湯設定温度よりも高い温度の出湯温度となるように適切な混合比率に調整するものである。このとき、混合弁８で調整する出湯温度を給湯設定温度よりも少しだけ高い一定温度に調整するようにして、第１貯湯タンク２Ａの中温水を第２貯湯タンク２Ｂの高温水よりも優先してなるべく多く使用するようにしていると共に、一定温度の出湯を行うようにしているので、その下流に設けられた温調ミキシング弁１２で給湯設定温度に調整するときの温調動作が安定するものである。
【００５１】
そして、第１貯湯タンク２Ａ内から中温水を全て給湯しきってしまった後は、図５に示すように、前記制御手段３４によって前記混合弁８が第２貯湯タンク２Ｂ側の開度を全開にされて、第２貯湯タンク２Ｂに貯められた高温水を用いて給湯が行われるようにしているものである。このように、給湯に利用可能な中温水があるにもかかわらず第２貯湯タンク２Ｂの高温水をムダに給湯してしまうことがなく、熱源としての能力を確保できる。
【００５２】
なお、もしも保温あるいは追焚き中に第２貯湯タンク２Ｂの高温水を使い切ってしまった場合は、前記制御手段３５がヒーポン循環回路２４の加熱切換弁２７を第２貯湯タンク２Ｂ側に切換えると共にヒートポンプ回路２２を駆動して、第２貯湯タンク２Ｂの下部から取り出した低温水を沸き上げて同第２貯湯タンク２Ｂの上部に戻し、保温あるいは追焚きの熱源となる高温水の供給源となる第２貯湯タンク２Ｂに貯めるようにすることで、沸き上げられた熱交換効率の高い高温水を保温あるいは追焚きの熱源として用い、そして熱交換により生成された中温水を第１貯湯タンク２Ａの上部に貯めて給湯が行われたときに用いるので、効率的に湯水の熱を分配しながら保温あるいは追焚きを行えるようにしているものである。
【００５３】
また、保温あるいは追焚き中に、同時に給湯が行われた場合は、第２貯湯タンク２Ｂ上部の高温水を保温あるいは追焚きの熱源として用い、そして熱交換により生成された中温水を第１貯湯タンク２Ａを中継して給湯することができ、熱交換効率の高い高温水を保温あるいは追焚きに用い、それによって生成された中温水を４０℃程度の給湯設定温度にされることが多い給湯に用いるので、効率的に貯湯されている湯水の熱を分配できて熱の使用効率がよいものである。
【００５４】
このように、安価な深夜の電力により沸き上げた高温水を熱源として使用することができ、そして熱交換により生成された中温水は第１貯湯タンク２Ａに貯められるので第２貯湯タンク２Ｂに貯められている高温水と混じることがなくなって、残っている高温水の温度を低下させることがないと共に、第１貯湯タンク２Ａに貯められた中温水は、その下方に貯められた低温水と混じり合うことがなく出湯に有効に使用できる温度のままで貯めておくことができ、そして、この第１貯湯タンク２Ａの上部に接続されている第１出湯管７Ａから出湯させることができるので、この貯められた中温水を全て使い切ることが可能となるものである。
【００５５】
さらに、並列に設けた２つの貯湯タンク２の内、第１貯湯タンク２Ａ中温水を貯めると共に、混合弁８によって第１貯湯タンク２Ａに貯湯されている高温水あるいは中温水を第２貯湯タンク２Ｂに貯湯されている高温水よりも優先して給湯に使用するので、第２貯湯タンク２Ｂに高温水を残したままの状態で中温水を使い切ることができて、容量当たりの保有熱量が少ない中温水を長期にわたって貯めておくことがないものである。
【００５６】
また、貯湯されている量を全て使い切らなかったときでも、第１貯湯タンク２Ａおよび第２貯湯タンク２Ｂの下部には低温水が貯められることになるため、ヒートポンプ回路２２により沸き上げを行う際に、低温の湯水を冷媒−水熱交換器１９に流入させることができるために高効率でかつ高温の沸き上げを行うことができて省エネを促進できるものである。しかも、ヒーポン循環回路２３に加熱切換弁２７を備えているため、前記貯湯温度センサ１７Ａ、１７Ｂで各貯湯タンク２Ａ、２Ｂで検出した温度分布にもとづいて各貯湯タンク２Ａ、２Ｂの下部に貯められている低温水だけを選択して沸き上げることが可能となる。
【００５７】
また、沸き上げ開始を開始する際は第１貯湯タンク２Ａ側から行うようにして、ヒートポンプ回路２２の出力が安定するまでの間に生成される中温水を第１貯湯タンク２Ａ側に貯めるようにしているので、その後の給湯時に第１貯湯タンク２Ａ側の湯水が第２貯湯タンク２Ｂよりも優先して先に給湯に使用されることとなるので、この中温水も全て使い切ることが可能となって沸き上げ初期に消費したエネルギーも無駄にすることなく有効に利用することができるものである。ここでは先に第１貯湯タンク２Ａ内の湯水を全て沸き上げるようにしているが、これに限らず、少なくともヒートポンプ回路２２の出力が安定するまでの間は前記加熱切換弁２７を第１貯湯タンク２Ａ側に切換えておくようにしておけばよいものである。
【００５８】
次に、本発明の他の一実施形態について図６に基づいて説明する。なお、先の一実施形態と同じものは同一の符号を付してその説明を省略することとする。
【００５９】
この一実施形態では先の一実施形態の混合弁８の代わりに、前記第１貯湯タンク２Ａまたは第２貯湯タンク２Ｂの一方から出湯させるよう流路を切換える出湯切換弁３６が設けられているものである。なお、この出湯切換弁３６は前記第１給水管６Ａと第２給水管６Ｂの分岐点に設けても良いものである。
【００６０】
また、風呂機能の代わりに暖房機能を備え、前記熱交換器２８の二次側には暖房循環回路３７が設けられ、この暖房循環回路３７途中に暖房循環ポンプ３８および暖房端末３９を備えているものである。なお、この暖房端末３９は多様の形態が考えられるもので、例えば床暖房パネル、温水式温風暖房機、温水式バス暖房乾燥機（温風式）、バス床暖房、パネルコンベクタなどが挙げられる。
【００６１】
そして、先の一実施形態と同じく、給湯栓４が開かれると、前記制御手段３５によって前記出湯切換弁３６が第１貯湯タンク２Ａ側に切換えられているので、、給水管６からの給水は第１給水管６Ａを流れて第１貯湯タンク２Ａへ下部から流入し、上部の第１出湯管７Ａから高温水が出湯管７に流出する。そして、前記温調ミキシング弁１２にてバイパス管１０からの水と混合されてリモコン等によって設定される給湯設定温度に調整されて給湯管１１を流れて給湯栓４から給湯される。
【００６２】
また、第１貯湯タンク２Ａの貯湯量が少ないか給湯量あるいは湯張り量が多く、第１貯湯タンク２Ａ内の高温水を使い切ってしまい第１貯湯タンク２Ａの側面に設けられた貯湯温度センサ１７Ａの最上部のセンサが所定温度以下の低温水を検出したら、前記制御手段３５により前記出湯切換弁３６が第２貯湯タンク２Ｂ側に切換えられて、第２貯湯タンク２Ｂに貯められた高温水を用いて給湯を行う。
【００６３】
次に、暖房を行う場合は、前記制御手段３５が暖房循環ポンプ３８を駆動して暖房循環回路３７内の循環液を熱交換器２８へ循環させると共に、熱交循環ポンプ２９を駆動して第２貯湯タンク２Ｂの上部に貯められている高温水を熱交循環回路３０を介して熱交換器２８へ循環させ、暖房循環回路３７の循環液とと第２貯湯タンク２Ｂに貯湯されていた高温水とを熱交換させて暖房を行う。
【００６４】
そして、第２貯湯タンク２Ｂから熱交換器２８に流入した高温水は暖房側との熱交換により温度低下し、生成された中温水は熱交循環ポンプ２９の作動によって第１貯湯タンク２Ａの上部に戻されると同時に、第１貯湯タンク２Ａの下部の給湯または湯張りによって流入していた低温水が熱交循環回路３０の一部を構成するヒーポン循環回路２４の第１ヒーポン往き管２５Ａと第２ヒーポン往き管２５Ｂを介して第２貯湯タンク２Ｂの下部に流入するようにして熱源となる温水を循環させるようにしているものである。また、第１貯湯タンク２Ａの上部に流れ込んだ中温水は、第１貯湯タンク２Ａの上部に高温水が残っている場合はこの高温水と混合され、また、第１貯湯タンク２Ａの高温水を全部使い切った後は中温水のままで第１貯湯タンク２Ａの上部に貯められることとなる。
【００６５】
次に、第１貯湯タンク２Ａに中温水が貯められている状態で給湯する場合は、給湯栓４が開かれると、前記制御手段３５によって前記出湯切換弁３６が第１貯湯タンク２Ａ側に切換えられているので、給湯の開始によって第１給水管６Ａからの低温水が第１貯湯タンク２Ａの下部に流入し、第１貯湯タンク２Ａの上部に貯められている中温水が第１出湯管７Ａから出湯する。そして、前記温調ミキシング弁１２にてバイパス管１０からの低温水と混合されて給湯設定温度に調整されて給湯されるものである。
【００６６】
ここで、もしも給湯設定温度が高温に設定され第１貯湯タンク２Ａに貯められている中温水が給湯に利用できない温度である場合あるいは第１貯湯タンク２Ａ内の中温水を全て使い切った後は、前記出湯切換弁３６を第２貯湯タンク２Ｂ側に切換えて第２貯湯タンク２Ｂに貯湯されている高温水を用いて給湯を行うようにしているものである。このように、給湯に利用可能な中温水があるにもかかわらず第２貯湯タンク２Ｂの高温水をムダに給湯してしまうことがなく、熱源としての能力を確保できる。
【００６７】
また、暖房動作中に、同時に給湯が行われた場合は、第２貯湯タンク２Ｂ上部の高温水を暖房の熱源として用い、そして熱交換により生成された中温水を第１貯湯タンク２Ａを中継して給湯することができ、熱交換効率の高い高温水を暖房に用い、それによって生成された中温水を４０℃程度の給湯設定温度にされることが多い給湯に用いるので、効率的に貯湯されている湯水の熱を分配できて熱の使用効率がよいものである。
【００６８】
このように、安価な深夜の電力により沸き上げた高温水を熱源として使用することができ、そして熱交換により生成された中温水は第１貯湯タンク２Ａに貯められるので第２貯湯タンク２Ｂに貯められている高温水と混じることがなくなって、残っている高温水の温度を低下させることがないと共に、第１貯湯タンク２Ａに貯められた中温水は、その下方に貯められた低温水と混じり合うことがなく出湯に有効に使用できる温度のままで貯めておくことができ、そして、この第１貯湯タンク２Ａの上部に接続されている第１出湯管７Ａから出湯させることができるので、この貯められた中温水を全て使い切ることが可能となるものである。
【００６９】
さらに、並列に設けた２つの貯湯タンク２の内、第１貯湯タンク２Ａ中温水を貯めると共に、出湯切換弁３６によって第１貯湯タンク２Ａに貯湯されている高温水あるいは中温水を第２貯湯タンク２Ｂに貯湯されている高温水よりも優先して給湯に使用するので、第２貯湯タンク２Ｂに高温水を残したままの状態で中温水を使い切ることができて、容量当たりの保有熱量が少ない中温水を長期にわたって貯めておくことがないものである。
【００７０】
なお、本発明はこれまで説明してきた実施形態に限定されるものではなく、発明の要旨を変更することなく設計変形可能な範囲に及ぶものであって、例えば熱交換器２８を熱交換器の一種として考えられる暖房端末して、この暖房端末に第２貯湯タンク２Ｂの高温水を直接循環させるようにしても良い。
【００７１】
また、請求項１〜３にかかる発明においては、加熱手段２２として例えば各貯湯タンク２Ａ、２Ｂ内に電熱ヒータをそれぞれ設けるようにしても良いものであり、また、加熱手段２２として貯湯タンク２外に電熱ヒータユニット等を設けるようにしても良いものであるが、実施形態中に示したように二酸化炭素冷媒を用いたヒートポンプ回路を加熱手段２２とすることによって、電気的な入力以上の熱エネルギーを取り出すことができると共に、高温の沸き上げができるという優れた効果を有している。
【００７２】
【発明の効果】
以上のように、本発明の請求項１によれば、貯湯タンク内に貯められた高温水を熱源として用いることができると共に、熱交換により生成された中温水が低温水と混じり合うことなく給湯に有効に利用できる温度のままで貯めておくことができ、しかも、この貯められた中温水を第２貯湯タンクの高温水よりも優先して給湯に用いるので、中温水を全て使い切ることが可能となるものであると共に、第１貯湯タンクに貯められた中温水が給湯に利用できない温度まで低下したとしても、第２貯湯タンクに貯められた高温水と混合して給湯に有効に利用可能な温度まで昇温して給湯に使用することが可能となり、給湯に不向きな温度の中温水であっても全て使い切ることが可能となるものである。しかも、給湯に利用可能な中温水があるにもかかわらず第２貯湯タンクの高温水をムダに給湯してしまうことがなく、熱源としての能力を確保できる。
更に第１および第２の貯湯タンクの下部には低温水が流入するものであり、この低温水を二酸化炭素冷媒を用いた超臨界ヒートポンプサイクルのヒートポンプ回路で加熱するので、高効率で高温の沸き上げが可能となるものである。
【００７３】
また、請求項２によれば、貯湯タンク内に貯められた高温水を熱源として用いることができると共に、熱交換により生成された中温水が低温水と混じり合うことなく給湯に有効に利用できる温度のままで貯めておくことができ、しかも、この貯められた中温水を第２貯湯タンクの高温水よりも優先して給湯に用いるので、中温水を全て使い切ることが可能となるものである。しかも、給湯に利用可能な中温水があるにもかかわらず第２貯湯タンクの高温水をムダに給湯してしまうことがなく、熱源としての能力を確保できる。
更に第１および第２の貯湯タンクの下部には低温水が流入するものであり、この低温水を二酸化炭素冷媒を用いた超臨界ヒートポンプサイクルのヒートポンプ回路で加熱するので、高効率で高温の沸き上げが可能となるものである。
【００７４】
また、請求項３によれば、貯湯タンクから出湯されてくる湯が高温あるいは中温であったとしても温調ミキシング弁によって給水管からの低温水と混合して任意の給湯温度で給湯を行うことができ、熱交換により生成された中温水を使い勝手良く給湯に用いることが可能となるものである。
【００７６】
また、請求項４によれば、加熱切換弁を切換えることによって一方の貯湯タンクを選択して沸き上げることができ、第１および第２の貯湯タンクのそれぞれの上部に高温水および中温水が残っている場合などにおいて、各貯湯タンクの下部に貯められている低温水だけを選択して沸き上げることが可能となると共に、各貯湯タンクへの配管の流通抵抗の差によって一方の貯湯タンクへ偏って沸き上げられてしまうなどの不都合がないものである。
【００７７】
また、請求項５によれば、沸き上げ動作時にヒートポンプ回路の出力が安定するまでに生成される中温水は第１貯湯タンクに貯められ、その後の給湯時に第１貯湯タンクの湯水が第２貯湯タンクよりも優先して給湯に使用されることとなり、この中温水も全て使い切ることが可能となって沸き上げ初期に消費したエネルギーも無駄にすることなく有効に利用することができるものである。
【００７８】
また、請求項６によれば、第２貯湯タンクの下部から取り出した低温水を沸き上げて同第２貯湯タンクの上部に戻し、熱源となる高温水の供給源となる第２貯湯タンクに貯めるようにすることで、沸き上げられた熱交換効率の高い高温水を直ぐに熱源として用い、そして熱交換により生成された中温水を第１貯湯タンクを介して給湯することができ、効率的に湯水の熱を分配できて熱の使用効率がよいものである。
【図面の簡単な説明】
【図１】本発明の一実施形態の概略構成図。
【図２】同一実施形態の給湯運転の作動を説明する図。
【図３】同一実施形態の風呂保温あるいは追焚き運転の作動を説明する図。
【図４】同一実施形態の中温水を用いた給湯運転の作動を説明する図。
【図５】同一実施形態の第１貯湯タンクに高温水および中温水がなくなってからの給湯運転の作動を説明する図。
【図６】本発明の他の一実施形態の概略構成図。
【図７】従来例の概略構成図。
【符号の説明】
２貯湯タンク
２Ａ第１貯湯タンク
２Ｂ第２貯湯タンク
６給水管
７出湯管
８混合弁
１０バイパス管
１１給湯管
１２温調ミキシング弁
２２ヒートポンプ回路（加熱手段）
２３ヒーポン循環回路
２７加熱切換弁
２８熱交換器
２９熱交循環ポンプ
３０熱交循環回路
３６出湯切換弁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot water storage type hot water supply apparatus including a heat exchanger that uses hot water in a hot water storage tank as a heat source.
[0002]
[Prior art]
Conventionally, in this type of hot water storage type hot water supply apparatus, high temperature water stored in a hot water storage tank disclosed in Japanese Patent Application No. 2002-39478 filed earlier by the present applicant is used as a heat source for reheating or heating a bath. There was something to do.
[0003]
This conventional one will be described with reference to FIG. 7. 101 is a heat pump circuit as a heating means, 102 is a hot water storage tank, and low temperature water taken out from the lower part of the hot water storage tank 102 is heated to a high temperature by the heat pump circuit 101. The stacked hot water is stored from the upper part of 102.
[0004]
A water supply pipe 103 is connected to the lower end of the hot water storage tank 102, and a hot water discharge pipe 104 is connected to the upper end. An electric mixing valve 105 mixes high-temperature water from the hot water discharge pipe 104 and low-temperature water from the water supply pipe 103 with an arbitrary hot water supply set temperature set by a remote controller (not shown) or the like and discharges the hot water from the hot water tap 106. It is.
[0005]
Reference numeral 107 denotes a heat exchanger as a heat source for heating, bathing, or keeping warm, which can be circulated with the hot water storage tank 102 by a heat transfer pipe 108 branched from the hot water discharge pipe 104 and a heat exchange return pipe 109 joined to the water supply pipe 103. The hot water in the hot water storage tank 102 is connected to the heat exchanger 107 to heat the hot water in a secondary circuit (not shown) such as a heating circuit, a bath reheating circuit or a heat retention circuit. is there.
[0006]
Then, the high temperature water taken out from the upper part of the hot water storage tank 102 is heat-exchanged by the heat exchanger 107 to lower the temperature and become medium temperature water, and returns to the hot water storage tank 102 from the lower part of the hot water storage tank 102.
[0007]
Although the applicant of the present application cannot find a known publication related to such a conventional hot water storage type hot water supply apparatus, it is assumed that heating is performed using high-temperature water stored in a hot water storage tank as a heat source. Is mentioned.
[0008]
[Patent Document 1]
Japanese Patent No. 2666337 (FIG. 1)
[0009]
[Problems to be solved by the invention]
However, in this conventional one, the medium-temperature water is stored in the hot water storage tank 102 by heat exchange in the heat exchanger 107, but this medium-temperature water is not suitable because it is low in temperature to be used as a heating or reheating heat source. In addition, if hot water is not supplied until the hot water runs out, medium temperature water with a small amount of retained heat per capacity remains in the hot water storage tank 102 indefinitely, reducing the retained heat amount of the hot water storage tank 102 and making it impossible to effectively use the capacity of the hot water storage tank. was there.
[0010]
[Means for Solving the Problems]
  In order to solve these problems, the present invention provides the first and second hot water storage tanks provided in parallel between the water supply pipe and the hot water discharge pipe for storing hot water and the first. And a heating means for heating the hot water in the second hot water storage tank to a high temperature, and a junction on the outlet side of the first and second hot water storage tanks or a branch point on the water supply side, from the first and second hot water storage tanks. A mixing valve capable of adjusting the ratio of the hot water to be discharged, a heat exchanger and a heat exchange circulation pump, wherein the upper part of the first hot water storage tank and the upper part of the second hot water storage tank communicate with each other, and the lower part of the first hot water storage tank and the first hot water tank A heat exchange circuit that communicates the lower part of the two hot water storage tanks, dissipates the high-temperature water taken out from the upper part of the second hot water storage tank by the heat exchanger, and returns the generated intermediate hot water to the upper part of the first hot water storage tank; The first hot water storage tank is high when hot water is supplied. Water or medium-temperature water than hot water of the second hot water storage tank so as to adjust an opening degree of the mixing valve to be used in preferenceFurthermore, a supercritical heat pump cycle is configured by using the heating means as a heat pump circuit using carbon dioxide refrigerant, and the first and second hot water storage tanks and the heat pump circuit can be circulated in parallel and hot water can be circulated in the heat pump circulation circuit. The hot water from the lower part of the first and second hot water storage tanks is heated by the heat pump circuit and returned to the upper part of the first and second hot water storage tanks..
[0011]
  As a result, the hot water in the first and second hot water storage tanks is heated to a high temperature by the heating means, and the opening degree on the first hot water tank side is opened fully or larger than that on the second hot water tank side by the mixing valve. The high temperature water stored in one hot water storage tank is used for hot water supply in preference to the second hot water storage tank. And when heating the secondary side using the hot water in the hot water storage tank as a heat source, the hot water taken out from the upper part of the second hot water storage tank is circulated to the heat exchanger via the heat exchange circuit by driving the heat exchange circulation pump. The intermediate temperature water generated by heat exchange with the secondary side is returned to the upper part of the first hot water storage tank. And while there is high temperature water or medium temperature water in the first hot water storage tank, the opening degree of the mixing valve is adjusted to prioritize the high temperature water or medium temperature water in the first hot water storage tank before the high temperature water in the second hot water storage tank. And it is used for hot water supply. At this time, even if the temperature of the medium-temperature water drops to a temperature that cannot be used for hot water supply, the medium-temperature water can be mixed with the high-temperature water in the second hot water storage tank by adjusting the opening of the mixing valve and can be used effectively for hot water supply. The temperature is raised to a temperature and medium temperature water is preferentially used for hot water supply. In addition, despite the fact that there is medium-temperature water that can be used for hot water supply, the hot water in the second hot water storage tank is not wasted and hot water capacity can be secured.
  Also, low temperature water flows into the lower portions of the first and second hot water storage tanks provided in parallel to the heat pump circuit by the use of hot water, and the low temperature water is circulated through the heat pump circulation circuit to emit carbon dioxide. Since heating is performed by a heat pump circuit of a supercritical heat pump cycle using a carbon refrigerant, high-temperature boiling can be achieved with high efficiency.
[0012]
  According to a second aspect of the present invention, the first and second hot water storage tanks provided in parallel between the water supply pipe and the hot water discharge pipe for storing hot water and the hot water in the first and second hot water storage tanks are heated to a high temperature. And a hot water switching valve that is provided at a junction point on the outlet side of the first and second hot water storage tanks or a branch point on the water supply side, and switches the flow path so that hot water is discharged from one of the first or second hot water storage tanks. An upper portion of the first hot water storage tank and an upper portion of the second hot water storage tank, and a lower portion of the first hot water storage tank and a lower portion of the second hot water storage tank, A high-temperature water taken out from the upper part of the second hot water storage tank is radiated by the heat exchanger, and the generated hot water is returned to the upper part of the first hot water storage tank. Use hot or medium hot water in hot water storage tanks Than hot water of the serial second hot water storage tank so as to switch the said tapping switching valve to be used in preferenceFurthermore, a supercritical heat pump cycle is configured by using the heating means as a heat pump circuit using carbon dioxide refrigerant, and the first and second hot water storage tanks and the heat pump circuit can be circulated in parallel and hot water can be circulated in the heat pump circulation circuit. The hot water from the lower part of the first and second hot water storage tanks is heated by the heat pump circuit and returned to the upper part of the first and second hot water storage tanks..
[0013]
  Thereby, the hot water in the first and second hot water storage tanks is heated to a high temperature by the heating means, and the hot water stored in the first hot water tank is selected by selecting the first hot water tank side by the hot water switching valve. Is used for hot water supply in preference to the second hot water storage tank. And when heating the secondary side using the hot water in the hot water storage tank as a heat source, the hot water taken out from the upper part of the second hot water storage tank is circulated to the heat exchanger via the heat exchange circuit by driving the heat exchange circulation pump. The intermediate temperature water generated by heat exchange with the secondary side is returned to the upper part of the first hot water storage tank. And when there is high temperature water or medium temperature water in the first hot water storage tank, the hot water switching valve is switched to the first hot water storage tank side so that the high temperature water or medium temperature water in the first hot water storage tank is higher than the high temperature water in the second hot water storage tank. Prior to use, it is used for hot water supply. In addition, despite the fact that there is medium-temperature water that can be used for hot water supply, the hot water in the second hot water storage tank is not wasted and hot water capacity can be secured.
  Also, low temperature water flows into the lower portions of the first and second hot water storage tanks provided in parallel to the heat pump circuit by the use of hot water, and the low temperature water is circulated through the heat pump circulation circuit to emit carbon dioxide. Since heating is performed by a heat pump circuit of a supercritical heat pump cycle using a carbon refrigerant, high-temperature boiling can be achieved with high efficiency.
[0014]
Moreover, in Claim 3, the bypass pipe which bypasses the said 1st, 2nd hot water storage tank from the said water supply pipe and merges with the said hot water pipe is provided, The junction of the said bypass pipe and the said hot water pipe, or the said bypass pipe, A temperature control mixing valve for adjusting the mixing ratio of the hot water flowing through the bypass pipe and the hot water outlet pipe to flow out to the hot water pipe is provided at the branch point of the water supply pipe.
[0015]
Thereby, even if the hot water discharged from the hot water storage tank is at a high temperature or a medium temperature, it can be mixed with the low temperature water from the water supply pipe by the temperature control mixing valve to supply hot water at an arbitrary hot water supply temperature.
[0018]
  Claims4Then, a heating switching valve is provided in the middle of the heat pump circulation circuit to select a hot water storage tank that selectively heats the heat pump circulation circuit to one of the first hot water storage tank and the second hot water storage tank.
[0019]
Thereby, by providing a heating switching valve for switching which of the first and second hot water storage tanks provided in parallel to the heat pump circuit, one of the hot water storage tanks can be selected and heated up, When high-temperature water and medium-temperature water remain in the upper portions of the first and second hot water storage tanks, for example, only low-temperature water stored in the lower portions of the hot water storage tanks can be selected and boiled up. At the same time, there is no inconvenience that the hot water is biased to one of the hot water storage tanks due to the difference in flow resistance of the pipes to the hot water storage tanks.
[0020]
  Claims5Then, during the boiling water operation by the heat pump circuit, the heating switching valve is switched to the first hot water storage tank side until the output of the heat pump circuit is stabilized.
[0021]
As a result, the medium-temperature water generated until the output of the heat pump circuit is stabilized during the boiling operation is stored in the first hot water storage tank by the heating switching valve being switched to the first hot water storage tank side, and then the hot water supply thereafter Sometimes the hot water in the first hot water storage tank is used for hot water supply in preference to the second hot water storage tank, and all of the medium hot water can be used up without wasting energy consumed at the beginning of boiling. It can be used effectively.
[0022]
  Claims6Then, at the time of boiling water operation by the heat pump circuit during operation of the heat exchange circulation pump, the heating switching valve is switched to the second hot water tank side so as to boil hot water on the second hot water tank side. I made it.
[0023]
As a result, when it is necessary to increase the boiling temperature due to insufficient hot water in the second hot water storage tank during the heat exchange with the secondary side on which the heat exchange circulation pump is operating, the heating switching valve is turned on. 2 Switch to the hot water storage tank side, boil the low-temperature water taken out from the lower part of the second hot water storage tank, return it to the upper part of the second hot water storage tank, and store it in the second hot water storage tank that serves as the heat source By using the high-temperature water boiled up and having high heat exchange efficiency as a heat source, the medium-temperature water generated by the heat exchange can be supplied via the first hot water storage tank. The heat can be distributed and the heat use efficiency is good.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Next, a hot water storage type hot water supply apparatus according to an embodiment of the present invention will be described with reference to the drawings. 2-5, the hatched hatching in the hot water storage tank 2 indicates low temperature water, the double hatched line indicates medium hot water, the triple hatched line indicates hot water, and the arrow indicates the flowing direction of the hot water.
[0025]
This hot water storage type hot water supply device boils and stores hot water in the midnight hours when the unit price of contracted power by time is low, and uses the hot water stored for hot water supply. 1 is a hot water storage tank 2 for storing hot water. 3 is a heat pump unit for heating hot water in the hot water storage tank, 4 is a hot water tap provided in a kitchen or bathroom, and 5 is a bathtub.
[0026]
In the hot water storage tank unit 1, a first hot water storage tank 2A and a second hot water storage tank 2B for storing hot water are provided in parallel between a water supply pipe 6 and a hot water discharge pipe 7, and are disposed below the first hot water storage tank 2A. A first hot water supply pipe 6A, a first hot water discharge pipe 7A are connected to the upper part, a second hot water supply pipe 6B is connected to the lower part of the second hot water storage tank 2B, and a second hot water discharge pipe 7B is connected to the upper part, respectively. A mixing valve 8 capable of adjusting the ratio of the hot water from the first hot water storage tank 2A or the second hot water storage tank 2B is provided at the junction with the pipe 7B, and the hot water temperature mixed downstream of the mixing valve 8 is provided. Is provided with a tapping temperature sensor 9. The mixing valve 8 may be provided at the branch point of the first water supply pipe 6A and the second water supply pipe 6B. In this case, the hot water temperature sensor 9 is not on the downstream side of the mixing valve 8 but the first water supply pipe. By providing the 6A and the 2nd water supply pipe 6B in the downstream of the confluence | merging point, the hot water temperature mixed can be detected and the mixing ratio of the mixing valve 8 can be adjusted appropriately.
[0027]
A bypass pipe 10 bypasses the first hot water storage tank 2 </ b> A and the second hot water storage tank 2 </ b> B from the water supply pipe 6 and joins the hot water discharge pipe 7. The bypass pipe 10 is provided at the junction of the bypass pipe 10 and the hot water discharge pipe 6. A temperature at which hot water of an arbitrary hot water set temperature set by a remote controller (not shown) or the like is adjusted to adjust the mixing ratio of hot water flowing through the bypass pipe 10 and the hot water outlet pipe 7 to the hot water pipe 11 connected to the hot water tap 4. It is communicated via the mixing valve 12.
[0028]
A hot water temperature sensor 13 is provided in the hot water supply pipe 11 on the outlet side of the temperature control mixing valve 12 and detects the temperature of hot water supplied from the hot water supply pipe 11. The temperature control mixing valve 12 is in accordance with the detected temperature. The mixing ratio is adjusted. A hot water supply flow counter 14 is provided in the hot water supply pipe 11 and counts the hot water supply flow rate. A pressure reducing valve 15 is provided in the water supply pipe 6 to reduce the water supply pressure. A water supply temperature sensor 16 is provided in the water supply pipe 6 on the downstream side of the pressure reducing valve 15 and detects the temperature of the water supply.
[0029]
The first hot water storage tank 2A and the second hot water storage tank 2B are provided with a plurality of hot water temperature sensors 17A and 17B in the vertical direction, respectively, to detect the temperature of the hot water stored in the hot water storage tanks 2A and 2B. The amount of remaining hot water in each hot water storage tank 2A, 2B and the temperature distribution in the vertical direction are roughly detected.
[0030]
Next, the heat pump unit 3 includes a compressor 18, a refrigerant-water heat exchanger 19 as a condenser, an electronic expansion valve 20, and an air heat exchanger 21 as an evaporator. And a heat pump circulation pump 24 that circulates hot water as heated water in each of the hot water storage tanks 2A and 2B to the refrigerant-water heat exchanger 19 through the heat pump circulation circuit 23, and in the refrigerant circuit of the heat pump circuit 22 Is filled with carbon dioxide as a refrigerant to constitute a supercritical heat pump cycle. Since carbon dioxide is used as the refrigerant, low-temperature water can be boiled up to a high temperature of about 90 ° C. without an electric heater.
[0031]
Here, the refrigerant-water heat exchanger 19 adopts a counter flow system in which the refrigerant and hot water as the water to be heated flow opposite to each other. In the supercritical heat pump cycle, the refrigerant remains in a supercritical state during heat exchange. Since the water is heated, the heated water can be efficiently heated to a high temperature, and the electronic expansion is performed so that the temperature difference ΔT between the refrigerant-water heat exchanger 19 inlet temperature and the refrigerant outlet temperature is constant. By controlling the valve 20 or the compressor 18, when the inlet temperature of the refrigerant-water heat exchanger 19 to be heated is about 15 ° C., the COP (energy consumption efficiency) is as high as 3.0 or more. Can be heated.
[0032]
A first hot water storage tank 2A and a second hot water storage tank 2B are provided in parallel between the heat pump forward pipe 25 and the heat pump return pipe 26 of the heat pump circulation circuit 23 on the hot water storage tank unit 1 side. The first heat pump return pipe 25A is connected to the lower part of the hot water storage tank 2A, the first heat pump return pipe 26A is connected to the upper part, the second heat pump return pipe 25B is connected to the lower part of the second hot water storage tank 2B, and the second heat pump return pipe 26B is connected to the upper part. One of the first hot water storage tank 2A and the second hot water storage tank 2B is selectively communicated with the water side of the refrigerant-water heat exchanger 19 at the branch point of the first heat pump return pipe 26A and the second heat pump return pipe 26B. A heating switching valve 27 composed of a three-way valve is provided. The heating switching valve 27 may be provided at the junction of the first and second heaton return pipes 25A and 25B, and the first heaton return pipe 26A and the second heaton return pipe 26B or the first heaton return pipe 26B. It may be configured by open / close valves respectively provided in the forward pipe 25A and the second heaton forward pipe 25B.
[0033]
Next, 28 is a heat exchanger for heating the hot water in the bathtub 5, 29 is a heat exchange circulation pump for circulating high-temperature water in the hot water storage tank 2 serving as a heat source on the primary side of the heat exchanger 28, 30 The upper part of the second hot water storage tank 2B, the heat exchanger 28, the heat exchanger pump 29, and the upper part of the first hot water storage tank 2A are communicated in order from the upstream side, and the lower part of the first hot water storage tank 2A and the lower part of the second hot water storage tank 2B are communicated. In the heat exchange circuit, the high temperature water taken out from the upper part of the second hot water storage tank 2B is caused to flow into the heat exchanger 28, and the intermediate hot water generated by heat exchange with the bath water is returned to the upper part of the first hot water storage tank 2A. It is what.
[0034]
Here, the side of the heat exchange circuit 30 that communicates the lower part of the first hot water storage tank 2A and the lower part of the second hot water storage tank 2B is the first heat pump forward pipe 25A and the second heat pump forward pipe 25B of the heat pump circulation circuit 24. It also serves as a part of the heat-pump circuit 24, so that the number of pipes and the number of connections to the hot water storage tanks 2A, 2B can be reduced, thereby reducing costs. . The side of the heat exchanger circuit 30 that communicates the lower part of the first hot water storage tank 2A and the lower part of the second hot water storage tank 2B may be shared by the first water supply pipe 6A and the second water supply pipe 6B. A dedicated pipe may be provided.
[0035]
Further, a bath circulation circuit 31 is connected to the secondary side of the heat exchanger 28 so that hot water in the bathtub 5 can be circulated, and hot water in the bathtub 5 is circulated to the heat exchanger 28 by a bath circulation pump 32. In this way, bath water is chased or kept warm by using the high temperature water from the second hot water storage tank 2B as a heat source.
[0036]
A hot water filling pipe 33 branched from the hot water supply pipe 11 is connected to the bath circulation circuit 31, and a hot water filling valve 34 provided on the hot water filling pipe 33 is opened to provide a predetermined amount of water to the bathtub 5. Alternatively, hot water filling at a predetermined water level is performed.
[0037]
Reference numeral 35 denotes a control means for drivingly controlling each actuator in accordance with a program stored in advance by receiving a detection value of each sensor of the hot water storage type hot water supply apparatus or a command from a remote controller (not shown).
[0038]
Here, the operation when boiling hot water in the hot water storage tank 2 in the midnight time zone will be described. The control means 35 operates the compressor 18 of the heat pump unit 3 and the heating switching valve 27 is the first. The water is switched to the 1 hot water storage tank 2A side, and the water filled in the first hot water storage tank 2A is transferred to the refrigerant-water heat exchanger 19 of the heat pump unit 3 by the heat pump circulation pump 24 via the lower first heat pump outgoing pipe 24A. The heated high temperature water flows through the first heat pump return pipe 25A, returns from the upper part of the first hot water storage tank 2A, and is stored in a stacked form.
[0039]
When the hot water storage temperature sensor 17A detects that the first hot water storage tank 2A has been boiled, the heating switching valve 27 is switched to the second hot water storage tank 2B, and the water filled in the second hot water storage tank 2B. Is heated in the heat pump unit 3 in the same manner as the boiling of the first hot water storage tank 2A through the lower second heat pump forward pipe 25B.
[0040]
In this way, since one of the hot water storage tanks 2 is boiled first, the hot water in the hot water storage tank 2 can be easily boiled while managing only a necessary amount, and the first heat pump forward pipe 25A and the first There is no inconvenience that the two heat pump return pipes 25B or the first heat pump return pipe 26A and the second heat pump return pipe 26B are slightly heated to the unintended one of the hot water storage tanks 2 due to a small difference in flow resistance. When the required amount is boiled, the hot water in the first hot water storage tank 2A is used preferentially over the hot water in the second hot water storage tank 2B, so that the first hot water discharge pipe 7A and the second hot water discharge pipe 7B meet. The mixing valve 8 provided waits for the opening of the first hot water storage tank 2A to be fully opened and hot water supply to be started.
[0041]
In addition, although the structure which boiled the 1st hot water storage tank 2A first was demonstrated here, after boiling the 2nd hot water storage tank 2B previously, you may make it boil the 1st hot water storage tank 2A, or the said heating switching It does not prevent the valve 27 from being switched to an intermediate position between the first hot water storage tank 2A and the second hot water storage tank 2B so as to boil both at once.
[0042]
When the hot water supply tank 2 or the hot water filling to the bathtub 5 is performed while the hot water storage tank 2 is being boiled, as shown in FIG. Since the opening of the mixing valve 8 on the first hot water storage tank 2A side is fully opened by this, the water supply from the water supply pipe 6 flows through the first water supply pipe 6A and flows into the first hot water storage tank 2A from the lower part. Hot water flows out from the first hot water discharge pipe 7 </ b> A into the hot water discharge pipe 7. Then, the temperature control mixing valve 12 is mixed with water from the bypass pipe 10, adjusted to a hot water set temperature or bath set temperature set by a remote controller or the like, flows through the hot water pipe 11, and is supplied with hot water from the hot water tap 4. Alternatively, it flows through the hot water filling pipe 33 and is hot watered in the bathtub 5 via the bath circulation circuit 31.
[0043]
At this time, since the opening degree of the mixing valve 8 on the second hot water storage tank 2B side is fully closed and the flow path is closed, the low temperature water does not flow into the second hot water storage tank 2B, and the high temperature is high. The state in which the hot water is stored is continued, and the same amount of low temperature water as the high temperature water that has flowed out is stored in the lower part of the first hot water storage tank 2A. Here, in the first hot water storage tank 2A, high temperature water is stored in the upper part and low temperature water is stored in the lower part. A difference in specific gravity occurs due to the temperature difference, and a high temperature water having a low specific gravity is formed by forming a temperature boundary layer. In addition, since the low-temperature water having a high specific gravity is located in the lower part, they do not mix with each other.
[0044]
Then, the hot water tap 4 is closed, or the hot water flow rate counter 14 counts the amount of hot water set by a remote controller or the like, or a water level sensor (not shown) provided in the middle of the bath circulation circuit 31 sets the predetermined water level. When the hot water filling valve 34 is detected and detected, hot water supply or hot water filling stops.
[0045]
Here, the amount of hot water stored in the first hot water storage tank 2A is small, the amount of hot water supplied or the amount of hot water filled is large, the hot water in the first hot water storage tank 2A is used up, and the hot water storage temperature sensor provided on the side surface of the first hot water storage tank 2A. When the uppermost sensor of 17A detects low-temperature water below a predetermined temperature, the control valve 35 fully opens the opening of the mixing valve 8 on the second hot water tank 2B side and is stored in the second hot water tank 2B. Hot water supply or hot water filling is performed using high-temperature water.
[0046]
Next, when the hot water filled in the bathtub 5 is kept warm or replenished, the control means 35 drives the bath circulation pump 32 to heat the hot water in the bathtub 5 as shown in FIG. The high-temperature water stored in the upper part of the second hot water storage tank 2B is circulated to the heat exchanger 28 via the heat exchange circuit 30 and the hot water in the bathtub 5 is driven. The hot water stored in the second hot water storage tank 2B is subjected to heat exchange to perform heat insulation or chasing.
[0047]
The high temperature water flowing into the heat exchanger 28 from the second hot water storage tank 2B is lowered in temperature by heat exchange with the bathtub water, and the generated intermediate temperature water is operated at the upper part of the first hot water storage tank 2A by the operation of the heat exchange circulation pump 29. At the same time, the low temperature water that has flowed in due to the hot water supply or hot water filling in the lower part of the first hot water storage tank 2A and the first heat pump forward pipe 25A of the heat pump circulation circuit 24 constituting a part of the heat exchange circuit 30 and the first The hot water serving as the heat source is circulated so as to flow into the lower part of the second hot water storage tank 2B through the two-heat-pone forward pipe 25B. Here, in the second hot water storage tank 2B, high temperature water is stored in the upper part and low temperature water is stored in the lower part. A specific gravity difference occurs due to the temperature difference, and a high temperature water having a low specific gravity is formed by forming a temperature boundary layer. Since the low temperature water with heavy specific gravity is located in the upper part, they are not mixed with each other.
[0048]
Further, the medium temperature water flowing into the upper part of the first hot water storage tank 2A is mixed with the high temperature water when the high temperature water remains in the upper part of the first hot water storage tank 2A. After all the water is used up, it is stored in the upper part of the first hot water storage tank 2A while maintaining the medium temperature water. Even in this case, a specific gravity difference is generated due to a temperature difference between the upper middle temperature water and the lower lower temperature water, and a temperature boundary layer is not formed to be mixed with each other. In this way, the medium-temperature water generated by heat exchange is all stored in the first hot water storage tank 2A at a temperature that can be effectively used for hot water supply.
[0049]
Next, when hot water is supplied in a state where intermediate hot water is stored in the first hot water storage tank 2A, when the hot water tap 4 is opened as shown in FIG. Since the opening degree of the hot water storage tank 2A is fully opened, low temperature water from the first hot water supply pipe 6A flows into the lower part of the first hot water storage tank 2A and is stored in the upper part of the first hot water storage tank 2A. The hot water that is being poured out from the first hot water discharge pipe 7A. And it mixes with the low temperature water from the bypass pipe 10 in the said temperature control mixing valve 12, is adjusted to hot water supply preset temperature, and hot water is supplied.
[0050]
Here, if the hot water supply set temperature is set to a high temperature and the medium hot water stored in the first hot water storage tank 2A cannot be used for hot water supply, the mixing valve 8 is based on the temperature detected by the hot water temperature sensor 9. The mixing ratio is adjusted so that the medium temperature water from the first hot water storage tank 2A and the high temperature water from the second hot water storage tank 2B are adjusted to an appropriate mixing ratio so that the hot water temperature is higher than the set hot water temperature. is there. At this time, the hot water temperature adjusted by the mixing valve 8 is adjusted to a constant temperature that is slightly higher than the hot water supply set temperature, and the medium temperature water of the first hot water storage tank 2A is given priority over the high temperature water of the second hot water storage tank 2B. Since the hot water is used as much as possible and the hot water is discharged at a constant temperature, the temperature adjustment operation when the temperature adjustment mixing valve 12 provided downstream is adjusted to the hot water supply set temperature is stable. It is.
[0051]
Then, after all the hot water has been supplied from the first hot water storage tank 2A, as shown in FIG. 5, the control valve 34 causes the mixing valve 8 to fully open the opening on the second hot water storage tank 2B side. Thus, hot water is supplied using the high temperature water stored in the second hot water storage tank 2B. Thus, despite the presence of medium-temperature water that can be used for hot water supply, the hot water in the second hot water storage tank 2B is not wasted and hot water capacity can be ensured.
[0052]
If the high temperature water in the second hot water storage tank 2B is used up while keeping warm or reheating, the control means 35 switches the heating switching valve 27 of the heat pump circulation circuit 24 to the second hot water storage tank 2B side and a heat pump. The circuit 22 is driven, the low-temperature water taken out from the lower part of the second hot water storage tank 2B is boiled and returned to the upper part of the second hot water storage tank 2B, and the first hot water supply source for heat retention or reheating is provided. 2 By storing in the hot water storage tank 2B, the high-temperature water boiled up with high heat exchange efficiency is used as a heat source for heat retention or reheating, and the intermediate temperature water generated by the heat exchange is used in the upper part of the first hot water storage tank 2A. This is used when hot water is stored and stored, so that heat can be kept warm or recharged while efficiently distributing hot water.
[0053]
In addition, when hot water is supplied at the same time during the heat insulation or reheating, the high temperature water in the upper part of the second hot water storage tank 2B is used as a heat source for heat insulation or reheating, and the medium temperature water generated by heat exchange is used as the first hot water storage. Hot water can be supplied via the tank 2A, and hot water with high heat exchange efficiency is used for heat insulation or reheating, and the medium temperature water generated thereby is often set to a hot water supply set temperature of about 40 ° C. Since it uses, the heat of the hot water stored efficiently can be distributed and the heat use efficiency is good.
[0054]
In this way, high-temperature water boiled by inexpensive late-night electricity can be used as a heat source, and the medium-temperature water generated by heat exchange is stored in the first hot water storage tank 2A, and is stored in the second hot water storage tank 2B. The hot water that is stored in the first hot water storage tank 2A is mixed with the low-temperature water stored in the first hot water storage tank 2A. The hot water can be stored at a temperature that can be effectively used for hot water without matching, and the hot water can be discharged from the first hot water pipe 7A connected to the upper part of the first hot water storage tank 2A. It is possible to use up all the stored medium temperature water.
[0055]
Further, of the two hot water storage tanks 2 provided in parallel, the hot water in the first hot water storage tank 2A is stored, and the high temperature water or the intermediate hot water stored in the first hot water storage tank 2A by the mixing valve 8 is stored in the second hot water storage tank 2B. It is used for hot water supply in preference to the hot water stored in the hot water, so the medium hot water can be used up with the high temperature water remaining in the second hot water storage tank 2B, and the amount of heat retained per capacity is low. Hot water is not stored for a long time.
[0056]
Even when the amount of hot water stored is not used up, low temperature water is stored in the lower part of the first hot water storage tank 2A and the second hot water storage tank 2B. Since low-temperature hot water can flow into the refrigerant-water heat exchanger 19, high-efficiency and high-temperature boiling can be performed, and energy saving can be promoted. In addition, since the heat-pump circulation circuit 23 is provided with the heating switching valve 27, it is stored under the hot water storage tanks 2A, 2B based on the temperature distribution detected by the hot water storage tanks 2A, 2B by the hot water storage temperature sensors 17A, 17B. It is possible to boil by selecting only low-temperature water.
[0057]
In addition, when the start of boiling is started, it is performed from the first hot water storage tank 2A side, and the medium hot water generated until the output of the heat pump circuit 22 is stabilized is stored in the first hot water storage tank 2A side. Therefore, during the subsequent hot water supply, the hot water on the first hot water storage tank 2A side is used prior to the second hot water storage tank 2B for hot water supply, so that all of the medium hot water can be used up. Thus, the energy consumed in the initial stage of boiling can be used effectively without wasting it. Here, all the hot water in the first hot water storage tank 2A is boiled up first, but this is not a limitation, and the heating switching valve 27 is set to the first hot water storage tank at least until the output of the heat pump circuit 22 is stabilized. It is only necessary to switch to the 2A side.
[0058]
Next, another embodiment of the present invention will be described with reference to FIG. The same components as those in the previous embodiment are denoted by the same reference numerals and the description thereof is omitted.
[0059]
In this embodiment, instead of the mixing valve 8 of the previous embodiment, a hot water switching valve 36 for switching the flow path so that hot water is discharged from one of the first hot water storage tank 2A or the second hot water storage tank 2B is provided. It is. The hot water switching valve 36 may be provided at a branch point between the first water supply pipe 6A and the second water supply pipe 6B.
[0060]
Further, a heating function is provided instead of the bath function, and a heating circulation circuit 37 is provided on the secondary side of the heat exchanger 28, and a heating circulation pump 38 and a heating terminal 39 are provided in the middle of the heating circulation circuit 37. Is. The heating terminal 39 may take various forms, such as a floor heating panel, a hot water hot air heater, a hot water bath heater / dryer (hot air type), a bath floor heater, a panel convector, and the like. It is done.
[0061]
As in the previous embodiment, when the hot-water tap 4 is opened, the hot water switching valve 36 is switched to the first hot water storage tank 2A side by the control means 35. The first hot water pipe 6A flows into the first hot water storage tank 2A from the lower part, and the high temperature water flows out from the upper first hot water pipe 7A to the hot water pipe 7. Then, it is mixed with water from the bypass pipe 10 by the temperature control mixing valve 12, adjusted to a hot water supply set temperature set by a remote controller or the like, flows through the hot water supply pipe 11, and is supplied from the hot water tap 4.
[0062]
Moreover, the hot water storage amount sensor 17A provided on the side surface of the first hot water storage tank 2A because the hot water storage amount of the first hot water storage tank 2A is small, the hot water supply amount or the hot water filling amount is large, and the high temperature water in the first hot water storage tank 2A is used up. When the uppermost sensor detects low temperature water below a predetermined temperature, the control means 35 switches the hot water switching valve 36 to the second hot water storage tank 2B side so that the hot water stored in the second hot water storage tank 2B is stored. Use to supply hot water.
[0063]
Next, when heating is performed, the control means 35 drives the heating circulation pump 38 to circulate the circulating fluid in the heating circulation circuit 37 to the heat exchanger 28 and also drives the heat exchange circulation pump 29 to perform the first operation. The high temperature water stored in the upper part of the two hot water storage tanks 2B is circulated to the heat exchanger 28 via the heat exchange circuit 30, and the high temperature stored in the circulating fluid of the heating circuit 37 and the second hot water storage tank 2B. Heat is exchanged with water.
[0064]
Then, the high temperature water flowing into the heat exchanger 28 from the second hot water storage tank 2B is lowered in temperature by heat exchange with the heating side, and the generated intermediate temperature water is operated at the upper part of the first hot water storage tank 2A by the operation of the heat exchange circulation pump 29. At the same time, the low temperature water that has flowed in due to the hot water supply or hot water filling in the lower part of the first hot water storage tank 2A and the first heat pump forward pipe 25A of the heat pump circulation circuit 24 constituting a part of the heat exchange circuit 30 and the first The hot water serving as the heat source is circulated so as to flow into the lower part of the second hot water storage tank 2B through the two-heat-pone forward pipe 25B. Further, the medium temperature water flowing into the upper part of the first hot water storage tank 2A is mixed with the high temperature water when the high temperature water remains in the upper part of the first hot water storage tank 2A. After all the water is used up, it is stored in the upper part of the first hot water storage tank 2A while maintaining the medium temperature water.
[0065]
Next, when hot water is supplied in a state where intermediate hot water is stored in the first hot water storage tank 2A, when the hot water tap 4 is opened, the hot water switching valve 36 is switched to the first hot water storage tank 2A side by the control means 35. Therefore, the low temperature water from the first water supply pipe 6A flows into the lower part of the first hot water storage tank 2A by the start of hot water supply, and the medium hot water stored in the upper part of the first hot water storage tank 2A becomes the first hot water pipe 7A. Take out the hot water from. And it mixes with the low temperature water from the bypass pipe 10 in the said temperature control mixing valve 12, is adjusted to hot water supply preset temperature, and hot water is supplied.
[0066]
Here, if the hot water supply set temperature is set to a high temperature and the medium hot water stored in the first hot water storage tank 2A cannot be used for hot water supply, or after all the medium hot water in the first hot water storage tank 2A is used up, The hot water supply switching valve 36 is switched to the second hot water storage tank 2B side so that hot water is supplied using hot water stored in the second hot water storage tank 2B. Thus, despite the presence of medium-temperature water that can be used for hot water supply, the hot water in the second hot water storage tank 2B is not wasted and hot water capacity can be ensured.
[0067]
In addition, when hot water is supplied simultaneously during the heating operation, the high temperature water in the upper part of the second hot water storage tank 2B is used as a heat source for heating, and the intermediate hot water generated by heat exchange is relayed to the first hot water storage tank 2A. Hot water with high heat exchange efficiency can be used for heating, and medium hot water generated thereby is used for hot water supply that is often set at a hot water supply set temperature of about 40 ° C. It is possible to distribute the heat of the hot water that is being used and the heat use efficiency is good.
[0068]
In this way, high-temperature water boiled by inexpensive late-night electricity can be used as a heat source, and the medium-temperature water generated by heat exchange is stored in the first hot water storage tank 2A, and is stored in the second hot water storage tank 2B. The hot water that is stored in the first hot water storage tank 2A is mixed with the low-temperature water stored in the first hot water storage tank 2A. The hot water can be stored at a temperature that can be effectively used for hot water without matching, and the hot water can be discharged from the first hot water pipe 7A connected to the upper part of the first hot water storage tank 2A. It is possible to use up all the stored medium temperature water.
[0069]
Further, of the two hot water storage tanks 2 provided in parallel, the hot water in the first hot water storage tank 2A is stored, and the hot or intermediate hot water stored in the first hot water storage tank 2A by the hot water switching valve 36 is stored in the second hot water storage tank. Since it is used for hot water supply in preference to the hot water stored in 2B, the medium hot water can be used up with the high temperature water remaining in the second hot water storage tank 2B, and the amount of heat retained per capacity is small. Medium temperature water is not stored for a long time.
[0070]
The present invention is not limited to the embodiments described so far, but covers a range that can be modified without changing the gist of the invention. For example, the heat exchanger 28 is replaced with a heat exchanger. A heating terminal that can be considered as a type may be used, and the hot water in the second hot water storage tank 2B may be directly circulated through the heating terminal.
[0071]
In the invention according to claims 1 to 3, for example, an electric heater may be provided in each of the hot water storage tanks 2A and 2B as the heating means 22, and the hot water storage tank 2 outside the hot water storage tank 2 may be provided. An electric heater unit or the like may be provided in the heater, but as shown in the embodiment, the heat pump circuit using the carbon dioxide refrigerant is used as the heating means 22 so that the heat energy more than the electrical input is obtained. Can be taken out and has an excellent effect of being able to boil at a high temperature.
[0072]
【The invention's effect】
  As described above, according to the first aspect of the present invention, the hot water stored in the hot water storage tank can be used as a heat source, and the hot water supplied by the heat exchange is not mixed with the low temperature water. It can be stored at a temperature that can be used effectively, and since the stored medium-temperature water is used for hot water supply in preference to the high-temperature water in the second hot water storage tank, all the medium-temperature water can be used up. In addition, even if the medium-temperature water stored in the first hot water storage tank drops to a temperature that cannot be used for hot water supply, it can be used effectively for hot water mixing with the high-temperature water stored in the second hot water storage tank. The temperature can be raised to a temperature and used for hot water supply, and even medium-temperature water having a temperature unsuitable for hot water supply can be used up. In addition, despite the fact that there is medium-temperature water that can be used for hot water supply, the hot water in the second hot water storage tank is not wasted and hot water capacity can be secured.
  Furthermore, low temperature water flows into the lower part of the first and second hot water storage tanks, and this low temperature water is heated by a heat pump circuit of a supercritical heat pump cycle using a carbon dioxide refrigerant. It can be raised.
[0073]
  According to the second aspect, the high-temperature water stored in the hot water storage tank can be used as a heat source, and the medium-temperature water generated by heat exchange can be effectively used for hot water supply without being mixed with low-temperature water. In addition, since the stored medium-temperature water is used for hot water supply in preference to the high-temperature water in the second hot water storage tank, all the medium-temperature water can be used up. In addition, despite the fact that there is medium-temperature water that can be used for hot water supply, the hot water in the second hot water storage tank is not wasted and hot water capacity can be secured.
  Furthermore, low temperature water flows into the lower part of the first and second hot water storage tanks, and this low temperature water is heated by a heat pump circuit of a supercritical heat pump cycle using a carbon dioxide refrigerant. It can be raised.
[0074]
According to the third aspect, even if the hot water discharged from the hot water storage tank is at a high temperature or a medium temperature, the hot water supply is performed at an arbitrary hot water supply temperature by mixing with the low temperature water from the water supply pipe by the temperature control mixing valve. Therefore, it is possible to use the warm water generated by heat exchange for hot water supply.
[0076]
  Claims4According to the above, when one of the hot water storage tanks can be selected and heated by switching the heating switching valve, high temperature water and medium temperature water remain in the upper part of each of the first and second hot water storage tanks. It is possible to boil by selecting only the low-temperature water stored in the lower part of each hot water storage tank, and the water is biased to one hot water storage tank due to the difference in the distribution resistance of the piping to each hot water storage tank. There is no inconvenience.
[0077]
  Claims5According to the above, medium-temperature water generated until the output of the heat pump circuit is stabilized during the boiling operation is stored in the first hot water storage tank, and the hot water in the first hot water storage tank has priority over the second hot water storage tank in the subsequent hot water supply. Thus, all of the medium-temperature water can be used up, and the energy consumed in the initial stage of boiling can be used effectively without wasting it.
[0078]
  Claims6According to the above, the low temperature water taken out from the lower part of the second hot water storage tank is boiled and returned to the upper part of the second hot water storage tank, and is stored in the second hot water storage tank which is a supply source of high temperature water which is a heat source. The heated high-temperature water with high heat exchange efficiency can be used as a heat source immediately, and the medium-temperature water generated by the heat exchange can be supplied through the first hot water storage tank to efficiently distribute the hot water heat. The heat use efficiency is good.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.
FIG. 2 is a view for explaining the operation of a hot water supply operation of the same embodiment.
FIG. 3 is a view for explaining the operation of bath insulation or chasing operation according to the same embodiment.
FIG. 4 is a diagram illustrating an operation of a hot water supply operation using medium-temperature water in the same embodiment.
FIG. 5 is a view for explaining an operation of a hot water supply operation after high temperature water and medium temperature water are exhausted in the first hot water storage tank of the same embodiment.
FIG. 6 is a schematic configuration diagram of another embodiment of the present invention.
FIG. 7 is a schematic configuration diagram of a conventional example.
[Explanation of symbols]
2 Hot water storage tank
2A 1st hot water storage tank
2B 2nd hot water storage tank
6 Water supply pipe
7 Hot water pipe
8 Mixing valve
10 Bypass pipe
11 Hot water supply pipe
12 Temperature control mixing valve
22 Heat pump circuit (heating means)
23 Heaton circulation circuit
27 Heating switching valve
28 Heat exchanger
29 Heat exchange circulation pump
30 Heat exchange circuit
36 Hot water selector valve

Claims

First and second hot water storage tanks provided in parallel between a water supply pipe and a hot water discharge pipe for storing hot water; heating means for heating hot water in the first and second hot water storage tanks to a high temperature; 1. A mixing valve, a heat exchanger, and a heat exchange circulation pump, which are provided at a junction point on the outlet side of the second hot water storage tank or a branch point on the water supply side and capable of adjusting the ratio of the hot water from the first and second hot water storage tanks. High temperature water taken out from the upper part of the second hot water storage tank, communicating with the upper part of the first hot water storage tank and the upper part of the second hot water storage tank, and communicating with the lower part of the first hot water storage tank and the lower part of the second hot water storage tank. A heat exchange circuit that radiates heat in the heat exchanger and returns the generated intermediate temperature water to the upper part of the first hot water storage tank, and when hot water is supplied, the hot water or intermediate temperature water in the first hot water storage tank is In preference to the hot water in the second hot water tank. An opening degree of the mixing valve so as to adjust to use, further together with the heating means constituting the supercritical heat pump cycle as a heat pump circuit using a carbon dioxide refrigerant, the said first and second hot water storage tank pump A circuit is connected in parallel with the heat pump circulation circuit so that hot water can circulate, and hot water from the lower portions of the first and second hot water storage tanks is heated by the heat pump circuit to the upper portions of the first and second hot water storage tanks. A hot water storage type hot water supply apparatus characterized by being configured to return .

First and second hot water storage tanks provided in parallel between a water supply pipe and a hot water discharge pipe for storing hot water; heating means for heating hot water in the first and second hot water storage tanks to a high temperature; 1. A hot water switching valve provided at a confluence of the hot water side of the second hot water storage tank or a branch point on the water supply side, for switching the flow path so as to discharge hot water from one of the first or second hot water storage tank, a heat exchanger and heat An exchange circulation pump is provided, and the upper part of the first hot water storage tank and the upper part of the second hot water storage tank are communicated, and the lower part of the first hot water storage tank and the lower part of the second hot water storage tank are communicated to be taken out from the upper part of the second hot water storage tank. The heat exchanger radiates heat with the heat exchanger and returns the generated intermediate warm water to the upper part of the first hot water storage tank. When supplying hot water, the hot water in the first hot water tank Warm water from the second hot water storage tank Together so as to switch the said tapping switching valve to be used in preference to the hot water, further constitutes a supercritical heat pump cycle said heating means as a heat pump circuit using a carbon dioxide refrigerant, the first and second hot water storage tank And the heat pump circuit are connected in parallel in a heat pump circuit so that hot water can be circulated, and hot water from the lower portions of the first and second hot water storage tanks is heated by the heat pump circuit, so that the first and second hot water storages are connected. A hot water storage hot water supply device characterized by being configured to return to the upper part of the tank .

A bypass pipe that bypasses the first and second hot water storage tanks from the water supply pipe and joins the hot water discharge pipe is provided, and a junction of the bypass pipe and the hot water discharge pipe or a branch point of the bypass pipe and the water supply pipe The hot water storage type hot water supply apparatus according to claim 1 or 2, further comprising a temperature control mixing valve that adjusts a mixing ratio of the hot water flowing through the bypass pipe and the hot water discharge pipe to flow out to the hot water supply pipe.

A heating switching valve is provided in the middle of the heat pump circulation circuit to select a hot water storage tank that selectively heats the heat pump circulation circuit to one of the first hot water storage tank and the second hot water storage tank. Item 4. The hot water storage type hot water supply apparatus according to items 1 to 3 .

During hot water boiling operation by the heat pump circuit, to the output of the heat pump circuit is stabilized, according to claim 4, characterized in that the heating switching valve was set to being switched to the first hot water storage tank The hot water storage type hot water supply apparatus described.

During the boiling operation of the hot water by the heat pump circuit during the operation of the heat exchange circulation pump, the heating switching valve is switched to the second hot water storage tank side so as to boil the hot water on the second hot water storage tank side. The hot water storage type hot water supply apparatus according to claim 4 .