JP3977241B2

JP3977241B2 - Hot water storage water heater

Info

Publication number: JP3977241B2
Application number: JP2002363192A
Authority: JP
Inventors: 直孝藍沢; 成樹村山; 誠本間
Original assignee: Corona Corp
Current assignee: Corona Corp
Priority date: 2002-12-16
Filing date: 2002-12-16
Publication date: 2007-09-19
Anticipated expiration: 2022-12-16
Also published as: JP2004197958A

Description

【０００１】
【発明の属する技術分野】
本発明は貯湯式給湯装置に関するものである。
【０００２】
【従来の技術】
従来よりこの種のものにおいては、図９に示すようなものがあった。
ここで、１０１はヒートポンプ回路、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５〜２５℃程度の低温水をヒートポンプ回路１０１で７０〜９０℃程度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。
【０００３】
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。
【０００４】
１０７は暖房あるいは風呂の追焚き／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あるいは風呂の追焚き／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。
【０００５】
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、３０〜５０℃程度の中間温度の湯水（以下、中間水とする）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。
【０００６】
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。
【０００７】
【特許文献１】
特許２６６３６３７号（図１）
【０００８】
【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３０〜５０℃程度の中間水が貯湯タンク１０２に貯まっていくが、この中間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間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ず、さらに貯湯タンク１０２内の水の沸き上げを行う場合、中間水をヒートポンプ回路１０１で再加熱するには温度が高いため効率が悪く、ヒートポンプ式給湯装置のＣＯＰ（エネルギー消費効率）を低下させてしまうという課題があった。
【０００９】
【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、湯水を貯湯する貯湯タンクと、この貯湯タンク内の湯水を加熱する加熱手段と、前記貯湯タンクの上部に接続された出湯管と、前記貯湯タンクの下部に接続された給水管と、この給水管から分岐された給水バイパス管と、前記出湯管からの湯水と前記給水バイパス管からの湯水とを混合する第１の混合弁と、前記貯湯タンクの中間部に接続された中間出湯管と、前記給水バイパス管途中に設けられ前記給水バイパス管を流れる湯水に中間出湯管からの湯水を混合する第２の混合弁と、給湯設定温度を設定する給湯温度設定手段と、給湯設定温度の湯水を供給すべく前記第１混合弁および第２混合弁の混合比率を調整する制御部とを備え、この制御部は、前記第２の混合弁の出口温度が給湯設定温度よりも所定温度低い温度となるように前記第２の混合弁の混合比率を調整すると共に、前記第１の混合弁の出口温度が給湯設定温度となるように前記第１の混合弁の混合比率を調整するようにしたものとした。
【００１０】
これにより、貯湯タンクの中間部の中間温度の湯水を中間出湯管から出湯し、第２混合弁および第１混合弁で給湯設定温度に適宜混合して優先的に消費するすることができる。
【００１１】
また、前記制御部は、前記第２の混合弁の出口温度が給湯設定温度よりも所定温度低い温度となるように前記第２の混合弁の混合比率を調整すると共に、前記第１の混合弁の出口温度が給湯設定温度となるように前記第１の混合弁の混合比率を調整するようにした。
【００１２】
これにより、中間温度の湯水は給湯時に中間出湯管から優先的に給湯されることとなり、中間温度の湯水で足りない熱量分を高温水を混合することで補うようにしているため、貯湯タンク上部の高温水の消費を抑えて湯切れしにくくなる。
【００１３】
また、請求項２では、前記制御部は、前記貯湯タンクの中間部の湯温が給湯設定温度よりも一定温度以上高い場合は、前記第２の混合弁の出口温度が給湯設定温度になるように第２の混合弁の混合比率を調整し、前記貯湯タンクの中間部の湯温が給湯設定温度よりも一定温度以上低い場合は、前記第２の混合弁の前記中間出湯管側を全開にすると共に前記第１の混合弁の出口温度が給湯設定温度となるように前記第１の混合弁の混合比率を調整するようにした。
【００１４】
これにより、貯湯タンクの中間部に貯まった湯水の温度に応じて第１混合弁および第２混合弁を適切に制御して、中間温度の中間水を優先的に使用しながら給湯設定温度の湯水を給湯することができ、中間温度の湯水で足りない熱量分を高温水を混合することで補うようにしているため、貯湯タンク上部の高温水の消費を抑えて湯切れしにくくなる。
【００１５】
また、請求項３では、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湯水が循環可能に接続し、前記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貯湯タンク上部へ戻すよう構成した。
【００１６】
これにより、貯湯タンクの沸き上げを行う際に、沸き上げ効率の悪い中間温度の湯水が無くなっているかあるいは少なくなっているため、ヒートポンプ回路のＣＯＰを低下させることが無く、しかも高温水の消費を抑えているので沸き上げ時間が短縮され、貯湯式給湯装置としての効率を向上させることができる。
【００１７】
【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、図中の貯湯タンク内にハッチングした斜線は低温水、二重斜線は中間水、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。
【００１８】
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は湯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２内の湯水を加熱する加熱手段たるヒートポンプユニット、４は台所や洗面所等に設けられた給湯栓、５は給湯栓４の近傍に設けられたリモコン、６は浴槽である。
【００１９】
前記貯湯タンクユニット１の貯湯タンク２は、上端に出湯管７と、下端に給水管８とが接続され、さらに、下部にヒーポン循環回路９を構成するヒーポン往き管９ａと、上部にヒーポン戻り管９ｂとが接続され、前記ヒーポン往き管９ａから取り出した貯湯タンク２内の湯水をヒートポンプユニット３によって沸き上げて、ヒーポン戻り管９ｂから貯湯タンク２内に戻して貯湯され、給水管８からの給水により貯湯タンク２内の湯水が押し上げられて貯湯タンク２内上部の高温水が出湯管７から押し出されて給湯されるものである。
【００２０】
前記ヒートポンプユニット３は、圧縮機１０と凝縮器としての冷媒−水熱交換器１１と電子膨張弁１２と強制空冷式の蒸発器１３とで構成された加熱手段としてのヒートポンプ回路１４と、貯湯タンク２内の湯水を前記ヒーポン循環回路９を介して冷媒−水熱交換器１１に循環させるヒーポン循環ポンプ１５と、それらの駆動を制御するヒーポン制御部１６とを備えており、ヒートポンプ回路１４内には冷媒として二酸化炭素が用いら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。
【００２１】
ここで、前記冷媒−水熱交換器１１は冷媒と被加熱水たる貯湯タンク２内の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１１入口温度と冷媒の出口温度との温度差が一定になるように前記電子膨張弁１２または圧縮機１０を制御することで、被加熱水の冷媒−水熱交換器１１の入口温度が５〜２０℃程度の低い温度であるとＣＯＰ（エネルギー消費効率）が３．０以上のとても良い状態で被加熱水を加熱することが可能なものである。
【００２２】
１７は前記浴槽６の湯水を加熱するための熱交換器で、その一次側には貯湯タンク２上部に接続された熱交往き管１８ａと貯湯タンク２下部に接続された熱交戻り管１８ｂとが接続されて熱交循環回路１８を構成し、熱交戻り管１８ｂ途中に設けられた熱交循環ポンプ２１の作動により貯湯タンク２から取り出した高温水を熱交換器１７に循環させ、熱交換により温度低下した中間水を再び貯湯タンク２内に戻すものである。
【００２３】
前記熱交換器１７の二次側には、浴槽６の湯水を循環可能にふろ往き管２０ａとふろ戻り管２０ｂより構成されるふろ循環回路２０が接続され、ふろ戻り管２０ｂ途中に設けられたふろ循環ポンプ２１の作動により浴槽６内の湯水が熱交換器１７に循環されて、一次側の高温水により加熱されて浴槽６内の湯水の保温あるいは追焚きが行われるものである。
【００２４】
次に、２２は出湯管７に設けられた第１混合弁で、給水管８から分岐された給水バイパス管２３からの湯水と出湯管７からの湯水とを前記リモコン５で設定される任意の給湯設定温度になるように混合比率を調整するものである。そして、この第１混合弁２２の下流には給湯温度センサ２４および給湯流量センサ２５を備えた給湯管２６が設けられ、給湯栓４と連通されているものである。
【００２５】
２７は貯湯タンク２の中間部に接続された中間出湯管で、貯湯タンク２の中央付近に貯められた中間水を出湯するものである。ここで中間水とは前記熱交換器１７の熱源として用いられて温度低下した湯水や、湯と水の温度境界層が崩れて中間温度となった湯水を意味する。また貯湯タンク２の中間出湯管２７が接続された近傍には中間位置での貯湯タンク２内部の温水温度を検出する中間温度センサ２８が設けられている。
【００２６】
２９は給水バイパス管２３途中に設けられ、この給水バイパス管２３を流れる湯水に中間出湯管２７からの湯水を混合させる第２混合弁である。この第２混合弁２９の下流には第２混合弁２９での混合温度を検出する混合温度センサ３０が設けられている。
【００２７】
次に、３１は貯湯タンク２の上下方向に複数個配置された貯湯温度センサで、この貯湯温度センサ３１が検出する温度情報によって、貯湯タンク２内にどれだけの熱量が残っているかを検知し、そして貯湯タンク２内の上下方向の温度分布を検知するものである。
【００２８】
前記リモコン５には、給湯設定温度を３５℃〜６０℃の範囲で任意に設定可能な給湯温度設定スイッチ３２が設けられ、給湯温度設定手段を構成しているものである。
【００２９】
３３は貯湯タンクユニット１内の各センサ類の入力を受けて各アクチュエータの駆動を制御するマイコンを有した給湯制御部で、この給湯制御部３３に前記リモコン５が無線または有線により接続され、ユーザーが任意の給湯設定温度を設定できるようにし、設定された給湯設定温度の湯水を供給すべく前記第１混合弁２２および第２混合弁２９の混合比率を調整するものである。
【００３０】
なお、３４は貯湯タンク２の過圧を逃す過圧逃し弁、３５は給水の温度を検出する給水温度センサ、３６は給水の圧力を減圧する減圧弁である。
【００３１】
次に、この一実施形態の作動を説明する。
まず、図２に示す沸き上げ運転について説明すると、深夜電力時間帯になって貯湯温度センサ３１が貯湯タンク２内に翌日に必要な熱量が残っていないことを検出すると、給湯制御部３３はヒーポン制御部１６に対して沸き上げ開始指令を発する。指令を受けたヒーポン制御部１６は圧縮機１０を起動した後にヒーポン循環ポンプ１５を駆動開始し、貯湯タンク２下部に接続されたヒーポン往き管９ａから取り出した５〜２０℃程度の低温水を冷媒−水熱交換器１１で７０〜９０℃程度の高温に加熱し、貯湯タンク２上部に接続されたヒーポン往き管９ｂから貯湯タンク２内に戻し、貯湯タンク２の上部から順次積層して高温水を貯湯していく。貯湯温度センサ３１が必要な熱量が貯湯されたことを検出すると、給湯制御部３３はヒーポン制御部１６に対して沸き上げ停止指令を発し、ヒーポン制御部１６は圧縮機１０を停止すると共にヒーポン循環ポンプ１５も停止して沸き上げ動作を終了するものである。
【００３２】
次に、給湯運転について説明すると、給湯栓４を開くと、給水管８からの給水が貯湯タンク２内に流れ込む。そしてこのとき、貯湯タンク２内の湯水と給水バイパス管２３からの水とが第１混合弁２２あるいは第２混合弁２９によって任意の給湯設定温度に混合されて給湯管２６から給湯されるものである。なお、貯湯タンク２内には上部に高温水、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がないものである。
【００３３】
ここで、第１混合弁２２と第２混合弁２９の両方あるいはどちらかを使うかの使い分けは、中間温度センサ２８の検出温度に基づき給湯制御部３３によって行われ、図７に示したフローチャートに基づいて説明すると、中間温度センサ２８の検出温度を給湯設定温度より一定温度（例えば５℃）高い温度と比較し（ステップ１、以下Ｓ１と略す）、高い場合はＳ２へ進み図３に示すように、第２混合弁２９で中間出湯管２７からの湯水と給水バイパス管２３からの水とを設定温度に混合して給湯するもので、第１混合弁２２ではその下流の給湯温度センサ２４が設定温度を検出するため結果的に弁の出湯管７側を全閉するようにしている。そして、給湯栓４が閉じられれば給湯は終了する。
【００３４】
次に、沸き上げ量が少なかったり給湯で高温水を消費した場合で給湯栓４を開いたとき、Ｓ１で中間温度センサ２８の検出温度を給湯設定温度より一定温度高い温度とを比較して低い場合は、Ｓ３で中間温度センサ２８の検出温度を給湯設定温度より一定温度（例えば５℃）低い温度と比較し、低い場合はＳ４へ進み図４に示すように、第２混合弁２９の下流の混合温度センサ３０が給湯設定温度以下を検出するため弁の中間出湯管２７側を全開にし、第１混合弁２２で出湯管７からの湯水を混合して給湯設定温度の湯を給湯するようにしている。そして、給湯栓４が閉じられれば給湯は終了する。
【００３５】
また、給湯栓４を開いたとき、中間温度センサ２８の検出温度が給湯設定温度より一定温度高い温度未満で給湯設定温度より一定温度低い温度以上のときは（Ｓ５）、図５に示すように第２混合弁２９で中間出湯管２７からの湯水と給水バイパス管２３からの水とを給湯設定温度より所定温度（例えば５℃）低い温度になるよう混合し、この混合された湯水に出湯管７からの湯水を混合して給湯設定温度の湯を給湯するように第１混合弁２２が制御されるものである。そして、給湯栓４が閉じられれば給湯は終了する。
【００３６】
このように、給湯を行う際に貯湯タンク２内の中間部に貯められている湯水の温度に応じて第１混合弁２２および第２混合弁２９が制御されるため、貯湯タンク２内に高温水と低温水の混じり合った中間温度の混合層ができたとしても、給湯設定温度に応じてこの中間温度の湯水を優先的に給湯に用いて上部に貯められた高温水の消費をできるだけ少なくすることができる。
【００３７】
そして、中間温度の湯水を優先的に給湯に使用することができることで、高温水の消費を抑えて湯切れしにくくなると共に、貯湯タンク２の沸き上げを行う際に、沸き上げ効率の悪い中間温度の湯水が無くなっているあるいは少なくなっているため、ヒートポンプ回路１４のＣＯＰを低下させることが無く、しかも高温水の消費を抑えているので沸き上げ時間が短縮され、貯湯式給湯装置としての効率を向上させることができるものである。
【００３８】
次に、ふろの追焚きあるいは保温動作について説明すると、図６に示すように、熱交循環ポンプ１９およびふろ循環ポンプ２１を駆動して、貯湯タンク２上部から取り出した７０〜９０℃程度の高温水を熱交換器１７の一次側へ循環させると共に、浴槽６内の湯水を熱交換器１７の二次側へ循環させて浴槽水の加熱を行い、追焚きあるいは保温を行う。そして、熱交換により３０〜５０℃程度まで温度低下した一次側の湯水は熱交戻り管１８ｂを介して貯湯タンク２の下部へ戻されるものである。なお、貯湯タンク２内には上部に高温水、中間部に中間水、下部に低温水が貯められることとなるが、その温度差が２０℃程度あれば比重差が発生し、温度境界層を形成して比重の軽い高温水が上部に、中間の中間水が中間部に、比重の重い低温水が下部に位置することとなり互いに混じり合うことがないものである。
【００３９】
このようにふろの追焚きあるいは保温によって中間温度の湯水が多量に発生しても、この中間温度の湯水は給湯時に中間出湯管２７から優先的に給湯されることとなり、中間温度の湯水で足りない熱量分を高温水を混合することで補うようにしているため、高温水の消費を抑えて湯切れしにくくなると共に、貯湯タンク２の沸き上げを行う際に、沸き上げ効率の悪い中間温度の湯水が無くなっているかあるいは少なくなっているため、ヒートポンプ回路１４のＣＯＰを低下させることが無く、しかも高温水の消費を抑えているので沸き上げ時間が短縮され、貯湯式給湯装置としての効率を向上させることができるという効果がいっそう顕著となるものである。
【００４０】
本発明はこの一実施形態に限定されるものではなく、例えば図７に示すように、貯湯タンク２内に熱交換器３７を配置し、この熱交換器３７に浴槽６の湯水を循環させることでふろの追焚きあるいは保温を行うようにしたものでもよく、また、前記図１および図７のものにおいて、ふろ循環回路２０の代わりに床暖房パネルや温水式コンベクタ、温水式ラジエータなどの暖房用の温水が循環する暖房循環回路を構成しても良く、貯湯タンク２内の高温水の熱を熱交換して利用するものであれば何でも良いものである。
【００４１】
【発明の効果】
以上のように、本発明によれば、中間温度の湯水は給湯時に中間出湯管から優先的に給湯されることとなり、中間温度の湯水で足りない熱量分を高温水を混合することで補うようにしているため、高温水の消費を抑えて湯切れしにくくなるという優れた効果を有するものである。
【００４２】
また、貯湯タンクの沸き上げを行う際に、沸き上げ効率の悪い中間温度の湯水が無くなっているかあるいは少なくなっているため、ヒートポンプ回路のＣＯＰを低下させることが無く、しかも高温水の消費を抑えているので沸き上げ時間が短縮され、貯湯式給湯装置としての効率を向上させることができるという優れた効果を有するものである。
【図面の簡単な説明】
【図１】本発明の一実施形態の貯湯式給湯装置の概略構成図。
【図２】同一実施形態の沸き上げ運転の作動を説明する図。
【図３】同一実施形態の給湯運転の作動を説明する図。
【図４】同一実施形態の給湯運転の作動を説明する図。
【図５】同一実施形態の給湯運転の作動を説明する図。
【図６】同一実施形態の追焚き／保温運転の作動を説明する図。
【図７】同一実施形態の第１混合弁および第２混合弁の制御を説明するフローチャート。
【図８】本発明の他の一実施形態の概略構成図。
【図９】従来の貯湯式給湯装置の概略構成図。
【符号の説明】
２貯湯タンク
３加熱手段（ヒートポンプユニット）
７出湯管
８給水管
９ヒーポン循環回路
１４ヒートポンプ回路
２２第１混合弁
２３給水バイパス管
２７中間出湯管
２９第２混合弁
３２給湯温度設定手段
３３給湯制御部（制御部）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot water storage type hot water supply apparatus.
[0002]
[Prior art]
Conventionally, this type has been shown in FIG.
Here, 101 is a heat pump circuit, 102 is a hot water storage tank, and low temperature water of about 5 to 25 ° C. taken out from the lower part of the hot water storage tank 102 is heated to about 70 to 90 ° C. by the heat pump circuit 101, and from the upper part of the hot water storage tank 102. Laminated hot water storage.
[0003]
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.
[0004]
Reference numeral 107 denotes a heat exchanger as a heat source for heating or bath reheating / keeping heat, 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 or a bath reheating / warming circuit. .
[0005]
And the high temperature water taken out from the upper part of the hot water storage tank 102 is heat-exchanged with the said heat exchanger 107, and temperature falls, and it becomes the hot water of the intermediate temperature of about 30-50 degreeC (henceforth intermediate water). The hot water tank 102 returns from the lower part of the hot water tank 102 to the hot water tank 102.
[0006]
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.
[0007]
[Patent Document 1]
Japanese Patent No. 2666337 (FIG. 1)
[0008]
[Problems to be solved by the invention]
However, in this conventional system, intermediate water of about 30 to 50 ° C. is stored in the hot water storage tank 102 by heat exchange in the heat exchanger 107. This intermediate water is used as a heat source for heating or reheating. Since the temperature is low, it is not suitable, and if the hot water is not supplied until it runs out, intermediate water with a small amount of heat per capacity will remain in the hot water storage tank 102 indefinitely, reducing the amount of heat stored in the hot water storage tank 102 and the capacity of the hot water storage tank. When the water in the hot water storage tank 102 cannot be effectively used, and the intermediate water is reheated by the heat pump circuit 101, the temperature is high and the efficiency is low, and the COP (energy consumption efficiency) of the heat pump hot water supply device ) Is reduced.
[0009]
[Means for Solving the Problems]
Accordingly, in order to solve these problems, the present invention provides a hot water storage tank for storing hot water, heating means for heating the hot water in the hot water storage tank, and hot water connected to an upper portion of the hot water storage tank. A first mixing unit for mixing a pipe, a water supply pipe connected to a lower portion of the hot water storage tank, a water supply bypass pipe branched from the water supply pipe, hot water from the hot water pipe and hot water from the water supply bypass pipe A valve, an intermediate hot water pipe connected to an intermediate portion of the hot water storage tank, a second mixing valve that mixes hot water from the intermediate hot water pipe with hot water that is provided in the middle of the water supply bypass pipe and flows through the water supply bypass pipe, A hot water supply temperature setting means for setting a hot water supply set temperature; and a control unit for adjusting a mixing ratio of the first mixing valve and the second mixing valve to supply hot water having a hot water supply set temperature . 2 Mixing valve exit The mixing ratio of the second mixing valve is adjusted so that the temperature becomes a predetermined temperature lower than the hot water supply set temperature, and the outlet temperature of the first mixing valve is set to the hot water supply set temperature. The mixing ratio of the mixing valve was adjusted .
[0010]
Thereby, the hot water of the intermediate temperature of the intermediate part of the hot water storage tank can be discharged from the intermediate hot water discharge pipe, and can be preferentially consumed by being appropriately mixed with the hot water supply set temperature by the second mixing valve and the first mixing valve.
[0011]
In addition , the control unit adjusts a mixing ratio of the second mixing valve so that an outlet temperature of the second mixing valve becomes a predetermined temperature lower than a hot water supply set temperature, and the first mixing valve The mixing ratio of the first mixing valve was adjusted so that the outlet temperature of the water became the hot water supply set temperature.
[0012]
As a result, the hot water at the intermediate temperature is preferentially supplied from the intermediate hot water pipe when hot water is supplied, and the amount of heat that is insufficient with the hot water at the intermediate temperature is compensated by mixing with hot water. Reduces consumption of hot water and makes it difficult to run out of hot water.
[0013]
According to a second aspect of the present invention, the controller controls the outlet temperature of the second mixing valve to be the hot water supply set temperature when the hot water temperature in the intermediate portion of the hot water storage tank is higher than the hot water supply set temperature by a certain temperature or more. When the mixing ratio of the second mixing valve is adjusted and the hot water temperature in the intermediate part of the hot water storage tank is lower than the set hot water temperature by a certain temperature or more, the intermediate hot water discharge pipe side of the second mixing valve is fully opened. In addition, the mixing ratio of the first mixing valve is adjusted so that the outlet temperature of the first mixing valve becomes the hot water supply set temperature.
[0014]
Accordingly, the first mixing valve and the second mixing valve are appropriately controlled according to the temperature of the hot water stored in the intermediate portion of the hot water storage tank, and the hot water at the hot water supply set temperature is used while preferentially using the intermediate water at the intermediate temperature. Since hot water is mixed with high-temperature water to compensate for the amount of heat that is insufficient with intermediate-temperature hot water, consumption of high-temperature water at the upper part of the hot water storage tank is suppressed, making it difficult for hot water to run out.
[0015]
According to a third aspect of the present invention, the heating means is a heat pump circuit using carbon dioxide refrigerant to constitute a supercritical heat pump cycle, and the hot water storage tank and the heat pump circuit are connected so that hot water can circulate in a heat pump circuit. The hot water from the lower part of the hot water storage tank is heated by the heat pump circuit and returned to the upper part of the hot water storage tank.
[0016]
As a result, when boiling the hot water storage tank, there is no or little intermediate temperature hot water with poor boiling efficiency, so that the COP of the heat pump circuit is not lowered and the consumption of high temperature water is reduced. Since it suppresses, boiling time is shortened and the efficiency as a hot water storage type hot water supply apparatus can be improved.
[0017]
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. In the figure, hatched hatched lines in the hot water storage tank indicate low temperature water, double hatched lines indicate intermediate water, triple hatched lines indicate hot water, and arrows indicate the flow direction of hot water.
[0018]
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 as a heating means for heating hot water in the hot water tank 2, 4 is a hot water tap provided in a kitchen or a washroom, etc. 5 is a remote controller provided in the vicinity of the hot water tap 4 , 6 is a bathtub.
[0019]
The hot water storage tank 2 of the hot water storage tank unit 1 has a hot water discharge pipe 7 connected to the upper end, a water supply pipe 8 connected to the lower end, a heat pump forward pipe 9a constituting a heat pump circulation circuit 9 in the lower part, and a heat pump return pipe in the upper part. 9b, hot water in the hot water storage tank 2 taken out from the heat pump outlet pipe 9a is boiled up by the heat pump unit 3 and returned to the hot water storage tank 2 from the heat pump return pipe 9b to be stored in hot water. As a result, hot water in the hot water storage tank 2 is pushed up, and high temperature water in the upper part of the hot water storage tank 2 is pushed out from the hot water discharge pipe 7 to supply hot water.
[0020]
The heat pump unit 3 includes a compressor 10, a refrigerant-water heat exchanger 11 as a condenser, an electronic expansion valve 12, a forced air-cooled evaporator 13, a heat pump circuit 14 as a heating means, and a hot water storage tank. 2 includes a heat pump circulation pump 15 that circulates the hot water in the refrigerant 2 through the heat pump circulation circuit 9 to the refrigerant-water heat exchanger 11, and a heat pump control unit 16 that controls driving thereof. Is one in which carbon dioxide is used 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.
[0021]
Here, the refrigerant-water heat exchanger 11 employs a counter flow system in which the refrigerant and hot water in the hot water storage tank 2 which is heated water are opposed to each other. In the supercritical heat pump cycle, the refrigerant is exchanged during heat exchange. Since it is condensed in the supercritical state, the water to be heated can be efficiently heated to a high temperature so that the temperature difference between the refrigerant-water heat exchanger 11 inlet temperature and the refrigerant outlet temperature becomes constant. By controlling the electronic expansion valve 12 or the compressor 10 at the same time, the COP (energy consumption efficiency) is 3 when the inlet temperature of the refrigerant-water heat exchanger 11 to be heated is a low temperature of about 5 to 20 ° C. It is possible to heat the water to be heated in a very good state of 0 or more.
[0022]
17 is a heat exchanger for heating the hot water in the bathtub 6, and on the primary side thereof, there are a heat transfer pipe 18 a connected to the upper part of the hot water storage tank 2 and a heat exchange return pipe 18 b connected to the lower part of the hot water storage tank 2. Is connected to form a heat exchange circuit 18, and high-temperature water taken out from the hot water storage tank 2 is circulated to the heat exchanger 17 by the operation of the heat exchange circulation pump 21 provided in the middle of the heat exchange return pipe 18 b to exchange heat. The intermediate water whose temperature has been lowered by the above is returned to the hot water storage tank 2 again.
[0023]
On the secondary side of the heat exchanger 17, a bath circulation circuit 20 composed of a bath tube 20a and a bath return tube 20b is connected to be able to circulate hot water in the bathtub 6, and is provided in the middle of the bath return tube 20b. The hot water in the bathtub 6 is circulated to the heat exchanger 17 by the operation of the bath circulation pump 21 and heated by the high-temperature water on the primary side, so that the hot water in the bathtub 6 is kept warm or chased.
[0024]
Next, reference numeral 22 denotes a first mixing valve provided in the hot water discharge pipe 7, which is an arbitrary set by the remote controller 5 for hot water from the water supply bypass pipe 23 branched from the water supply pipe 8 and hot water from the hot water discharge pipe 7. The mixing ratio is adjusted so that the hot water supply set temperature is reached. A hot water supply pipe 26 having a hot water supply temperature sensor 24 and a hot water supply flow rate sensor 25 is provided downstream of the first mixing valve 22, and communicates with the hot water tap 4.
[0025]
An intermediate hot water pipe 27 is connected to an intermediate portion of the hot water storage tank 2 and discharges intermediate water stored near the center of the hot water storage tank 2. Here, the intermediate water means hot water that has been used as a heat source for the heat exchanger 17 and whose temperature has dropped, or hot water that has reached an intermediate temperature due to collapse of the temperature boundary layer between the hot water and water. An intermediate temperature sensor 28 for detecting the temperature of hot water inside the hot water storage tank 2 at an intermediate position is provided in the vicinity of the hot water storage tank 2 where the intermediate hot water discharge pipe 27 is connected.
[0026]
A second mixing valve 29 is provided in the middle of the water supply bypass pipe 23 and mixes hot water from the intermediate hot water pipe 27 with hot water flowing through the water supply bypass pipe 23. A mixing temperature sensor 30 that detects the mixing temperature in the second mixing valve 29 is provided downstream of the second mixing valve 29.
[0027]
Next, a plurality of hot water storage temperature sensors 31 are arranged in the vertical direction of the hot water storage tank 2, and the amount of heat remaining in the hot water storage tank 2 is detected based on temperature information detected by the hot water storage temperature sensor 31. And the temperature distribution of the up-down direction in the hot water storage tank 2 is detected.
[0028]
The remote controller 5 is provided with a hot water supply temperature setting switch 32 that can arbitrarily set the hot water supply set temperature in a range of 35 ° C. to 60 ° C., and constitutes a hot water supply temperature setting means.
[0029]
Reference numeral 33 denotes a hot water supply control unit having a microcomputer that receives the input of each sensor in the hot water storage tank unit 1 and controls the drive of each actuator. The remote control 5 is connected to the hot water supply control unit 33 by wireless or wired connection. Can set an arbitrary hot water supply set temperature, and adjust the mixing ratio of the first mixing valve 22 and the second mixing valve 29 so as to supply hot water at the set hot water supply set temperature.
[0030]
In addition, 34 is an overpressure relief valve for releasing the overpressure of the hot water storage tank 2, 35 is a feed water temperature sensor for detecting the temperature of the feed water, and 36 is a pressure reducing valve for reducing the pressure of the feed water.
[0031]
Next, the operation of this embodiment will be described.
First, the boiling operation shown in FIG. 2 will be described. When the hot water storage temperature sensor 31 detects that the necessary amount of heat does not remain in the hot water storage tank 2 in the late-night power time zone, the hot water supply control unit 33 A boiling start command is issued to the control unit 16. Upon receiving the command, the heat pump controller 16 starts driving the heat pump after starting the compressor 10, and cools the low temperature water of about 5 to 20 ° C. taken out from the heat pump forward pipe 9 a connected to the lower part of the hot water storage tank 2 as a refrigerant. -Heated to a high temperature of about 70 to 90 ° C in the water heat exchanger 11, returned to the hot water storage tank 2 from the heat pump forward pipe 9b connected to the upper part of the hot water storage tank 2, and stacked in order from the upper part of the hot water storage tank 2 Store hot water. When the hot water storage temperature sensor 31 detects that the necessary amount of heat has been stored, the hot water supply control unit 33 issues a boiling stop command to the heat pump control unit 16, and the heat pump control unit 16 stops the compressor 10 and heat pump circulation. The pump 15 is also stopped and the boiling operation is finished.
[0032]
Next, the hot water supply operation will be described. When the hot water tap 4 is opened, the water supplied from the water supply pipe 8 flows into the hot water storage tank 2. At this time, the hot water in the hot water storage tank 2 and the water from the water supply bypass pipe 23 are mixed to an arbitrary hot water supply set temperature by the first mixing valve 22 or the second mixing valve 29 and supplied from the hot water supply pipe 26. is there. In the hot water storage tank 2, high temperature water is stored in the upper part and low temperature water is stored in the lower part. However, a specific gravity difference is generated due to the temperature difference, and a high temperature water having a low specific gravity is formed on the upper part by forming a temperature boundary layer. Since low-temperature water having a high specific gravity is located at the lower part, they do not mix with each other.
[0033]
Here, the use of either or both of the first mixing valve 22 and the second mixing valve 29 is performed by the hot water supply control unit 33 based on the temperature detected by the intermediate temperature sensor 28, and the flowchart shown in FIG. Explaining based on this, the temperature detected by the intermediate temperature sensor 28 is compared with a temperature that is higher than the hot water supply set temperature by a certain temperature (for example, 5 ° C.) (step 1, hereinafter abbreviated as S1). In addition, hot water from the intermediate tap pipe 27 and water from the feed water bypass pipe 23 are mixed to a set temperature by the second mixing valve 29 to supply hot water. The first mixing valve 22 has a hot water supply temperature sensor 24 downstream thereof. As a result, the outlet pipe 7 side of the valve is fully closed to detect the set temperature. And if the hot-water tap 4 is closed, hot water supply will be complete | finished.
[0034]
Next, when the hot water tap 4 is opened when the boiling amount is small or hot water is consumed by hot water supply, the detected temperature of the intermediate temperature sensor 28 is lower than the temperature set by the hot water supply temperature at a constant temperature in S1. If this is the case, the detected temperature of the intermediate temperature sensor 28 is compared with a temperature lower than the hot water supply set temperature by a certain temperature (for example, 5 ° C.) in S3, and if it is lower, the process proceeds to S4, as shown in FIG. In order for the mixing temperature sensor 30 to detect a hot water supply set temperature or less, the intermediate hot water discharge pipe 27 side of the valve is fully opened, and hot water from the hot water discharge pipe 7 is mixed by the first mixing valve 22 to supply hot water at the hot water supply set temperature. I have to. And if the hot-water tap 4 is closed, hot water supply will be complete | finished.
[0035]
Further, when the hot water tap 4 is opened, when the temperature detected by the intermediate temperature sensor 28 is lower than a certain temperature higher than the hot water supply set temperature and lower than a predetermined temperature lower than the hot water set temperature (S5), as shown in FIG. The hot water from the intermediate hot water pipe 27 and the water from the water supply bypass pipe 23 are mixed by the second mixing valve 29 so as to be a predetermined temperature (for example, 5 ° C.) lower than the hot water supply set temperature, and the hot water pipe is added to the mixed hot water. The first mixing valve 22 is controlled so as to mix hot water from 7 and supply hot water at a hot water supply set temperature. And if the hot-water tap 4 is closed, hot water supply will be complete | finished.
[0036]
Thus, since the 1st mixing valve 22 and the 2nd mixing valve 29 are controlled according to the temperature of the hot water currently stored in the intermediate part in the hot water storage tank 2 when supplying hot water, in the hot water storage tank 2 high temperature Even if a mixed layer of intermediate temperature mixed with water and low-temperature water is made, consumption of high-temperature water stored in the upper part is reduced as much as possible by using hot water of this intermediate temperature preferentially for hot water supply according to the hot water set temperature. can do.
[0037]
And since hot water of intermediate temperature can be preferentially used for hot water supply, it is difficult to run out of hot water by suppressing the consumption of high temperature water, and when the hot water storage tank 2 is heated, the boiling efficiency is low. Since there is no or little hot water in the temperature, the COP of the heat pump circuit 14 is not lowered, and consumption of high temperature water is suppressed, so that the boiling time is shortened and the efficiency as a hot water storage type hot water supply apparatus is reduced. Can be improved.
[0038]
Next, the bath reheating or heat retaining operation will be described. As shown in FIG. 6, the heat exchange circulation pump 19 and the bath circulation pump 21 are driven to take out a high temperature of about 70 to 90 ° C. taken out from the upper part of the hot water storage tank 2. Water is circulated to the primary side of the heat exchanger 17 and hot water in the tub 6 is circulated to the secondary side of the heat exchanger 17 to heat the tub water and to chase or keep warm. And the hot water of the primary side which fell in temperature to about 30-50 degreeC by heat exchange is returned to the lower part of the hot water storage tank 2 via the heat exchanger return pipe 18b. In the hot water storage tank 2, high temperature water is stored in the upper part, intermediate water is stored in the intermediate part, and low temperature water is stored in the lower part. If the temperature difference is about 20 ° C., a specific gravity difference occurs and a temperature boundary layer is formed. The high-temperature water having a low specific gravity is formed in the upper part, the intermediate intermediate water is in the intermediate part, and the low-temperature water having a high specific gravity is in the lower part, so that they do not mix with each other.
[0039]
Thus, even if a large amount of intermediate temperature hot water is generated by chasing or keeping warm, the intermediate temperature hot water is preferentially supplied from the intermediate outlet pipe 27 at the time of hot water supply, and the intermediate temperature hot water is sufficient. Since the amount of heat is not compensated for by mixing high temperature water, it is difficult to run out of hot water by suppressing the consumption of high temperature water, and when boiling the hot water storage tank 2, the intermediate temperature is low in boiling efficiency. Since there is no or little hot water, the COP of the heat pump circuit 14 is not lowered and the consumption of high-temperature water is reduced, so that the boiling time is shortened and the efficiency as a hot water storage hot water supply device is improved. The effect that it can be improved is even more remarkable.
[0040]
The present invention is not limited to this embodiment. For example, as shown in FIG. 7, a heat exchanger 37 is disposed in the hot water storage tank 2, and hot water in the bathtub 6 is circulated through the heat exchanger 37. 1 may be used for heating a floor heating panel, a hot water convector, a hot water radiator or the like in place of the bath circulation circuit 20 in FIG. 1 and FIG. A heating circulation circuit in which the hot water is circulated may be configured, and anything may be used as long as the heat of the hot water in the hot water storage tank 2 is used by heat exchange.
[0041]
【The invention's effect】
As described above, according to the present invention, hot water at an intermediate temperature is preferentially supplied from an intermediate outlet pipe at the time of hot water supply, and the amount of heat that is insufficient with the hot water at the intermediate temperature is compensated by mixing with hot water. Therefore, it has an excellent effect of suppressing consumption of high-temperature water and making it difficult to run out of hot water.
[0042]
In addition, when boiling the hot water storage tank, there is no or little hot water of intermediate temperature with low boiling efficiency, so the COP of the heat pump circuit is not lowered and the consumption of high temperature water is suppressed. Therefore, the boiling time is shortened and the efficiency as a hot water storage type hot water supply apparatus can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a hot water storage type hot water supply apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining the operation of a boiling operation according to the same embodiment.
FIG. 3 is a view for explaining the operation of a hot water supply operation according to the same embodiment.
FIG. 4 is a diagram for explaining the operation of a hot water supply operation according to the same embodiment.
FIG. 5 is a diagram for explaining the operation of the hot water supply operation of the same embodiment.
FIG. 6 is a diagram for explaining the operation of the chasing / warming operation of the same embodiment.
FIG. 7 is a flowchart for explaining control of a first mixing valve and a second mixing valve of the same embodiment.
FIG. 8 is a schematic configuration diagram of another embodiment of the present invention.
FIG. 9 is a schematic configuration diagram of a conventional hot water storage type hot water supply apparatus.
[Explanation of symbols]
2 Hot water storage tank 3 Heating means (heat pump unit)
7 Hot water outlet pipe 8 Water supply pipe 9 Heaton circulation circuit 14 Heat pump circuit 22 First mixing valve 23 Water supply bypass pipe 27 Intermediate hot water outlet pipe 29 Second mixing valve 32 Hot water supply temperature setting means 33 Hot water supply control section (control section)

Claims

A hot water storage tank for storing hot water, a heating means for heating the hot water in the hot water storage tank, a hot water pipe connected to the upper part of the hot water storage tank, a water supply pipe connected to the lower part of the hot water storage tank, and the water supply pipe A water supply bypass pipe branched from the first hot water from the hot water supply pipe and hot water from the water supply bypass pipe, an intermediate hot water pipe connected to an intermediate portion of the hot water storage tank, A second mixing valve that is provided in the middle of the water supply bypass pipe and mixes hot water from the intermediate hot water pipe with hot water flowing through the water supply bypass pipe, hot water supply temperature setting means for setting the hot water supply set temperature, and hot water at the hot water supply set temperature is supplied. And a control unit that adjusts the mixing ratio of the first mixing valve and the second mixing valve, and the control unit is configured such that the outlet temperature of the second mixing valve is lower than the preset hot water supply temperature by a predetermined temperature. Like the above While adjusting the mixing ratio of the mixing valve, the hot-water storage type, characterized in that the outlet temperature of the first mixing valve is to adjust the mixing ratio of the first mixing valve so that the hot water set temperature Hot water supply device.

When the hot water temperature in the intermediate portion of the hot water storage tank is higher than a predetermined hot water supply temperature by a certain temperature or more, the control unit controls the second mixing valve so that the outlet temperature of the second mixing valve becomes the hot water supply set temperature. When the mixing ratio is adjusted and the hot water temperature in the intermediate portion of the hot water storage tank is lower than the set hot water temperature by a certain temperature or more, the intermediate hot water discharge pipe side of the second mixing valve is fully opened and the first mixing is performed. hot water storage type hot water supply apparatus according to claim 1, wherein the outlet temperature of the valve is to adjust the mixing ratio of the first mixing valve so that the hot water set temperature.

The heating means is configured as a heat pump circuit using carbon dioxide refrigerant to constitute a supercritical heat pump cycle, and the hot water storage tank and the heat pump circuit are connected so that hot water can be circulated in a heat pump circulation circuit. The hot water storage type hot water supply apparatus according to claim 1 , wherein hot water is heated by the heat pump circuit and returned to the upper part of the hot water storage tank.