JP3878476B2

JP3878476B2 - Flow water heater

Info

Publication number: JP3878476B2
Application number: JP2001394518A
Authority: JP
Inventors: 英男岡本
Original assignee: Rinnai Corp
Current assignee: Rinnai Corp
Priority date: 2001-12-26
Filing date: 2001-12-26
Publication date: 2007-02-07
Anticipated expiration: 2021-12-26
Also published as: JP2003194404A

Description

【０００１】
【発明の属する技術分野】
本発明は、熱交換器からの出湯温度を所定温度以上に維持することによって、熱交換器からドレンが発生することを防止するフロー式水加熱装置に関する。
【０００２】
【従来の技術】
従来より、フロー式水加熱装置として、例えば、バーナにより加熱される熱交換器を有し、給水管から供給される水を該熱交換器で加熱することによって、所定の目標給湯温度の湯を給湯管に出湯するガス給湯装置が知られている。
【０００３】
かかるガス給湯装置においては、熱交換器からの出湯温度が低くなって熱交換器の周囲においてバーナの燃焼排ガスの温度が低くなると、燃焼排ガスの水蒸気がドレンとなって熱交換器の表面に付着するようになる。そして、このようにドレンが付着すると、熱交換器の腐食が生じて熱交換器の劣化が生じるという不都合がある。
【０００４】
そこで、熱交換器をバイパスして給水管と給湯管を連通するバイパス管と、熱交換器に供給される水の流量に対するバイパス管に供給される水の流量の比（バイパス比）を調節するためのバイパスサーボ弁を備え、熱交換器から出湯される湯の温度が、ドレンが生じないように予め定められたドレン防止温度となるように、バイパス比を調節して熱交換器に供給される水の流量を制御するガス給湯装置が提案されている。
【０００５】
そして、従来のガス給湯装置においては、前記ドレン防止温度が一定値に設定されていた。しかし、本願発明者らは、このように熱交換器の出湯温度が一定のドレン防止温度となるように、熱交換器に供給される水の流量を制御したときに、熱交換器の熱効率が必ずしも良好なものとはならないことを知見した。
【０００６】
【発明が解決しようとする課題】
本発明は、ドレンの発生を防止するために熱交換器からの出湯温度を制限する場合において、熱交換器の熱効率を向上させたフロー式水加熱装置を提供することを目的とする。
【０００７】
【課題を解決するための手段】
本発明は上記目的を達成するためになされたものであり、供給される水を加熱して出湯する熱交換器と、該熱交換器を加熱するバーナと、該バーナの燃焼量を調節する燃焼量調節手段と、所定条件に応じて該バーナの目標燃焼量を決定する目標燃焼量決定手段と、前記燃焼量調節手段により前記バーナの燃焼量を前記目標燃焼量に制御する燃焼量制御手段と、前記熱交換器から出湯される湯の温度を検出する熱交温度センサと、前記熱交換器に供給される水の流量を調節する熱交流量調節手段と、前記熱交温度センサの検出温度が所定のドレン防止温度となるように前記熱交換器に供給される水の流量を前記熱交流量調節手段により調節する熱交流量制御手段とを備えたフロー式水加熱装置の改良に関する。
【０００８】
かかるフロー式水加熱装置においては、詳細は後述するが、前記バーナの燃焼量が一定の場合は、前記熱交換器に供給される水の流量を大きくして前記熱交換器の出湯温度を低くした方が前記熱交換器の熱効率が高くなる。また、前記バーナの燃焼量が小さい程、前記熱交換器の周囲の温度が低くなって前記熱交換器にドレンが生じ易くなるため、前記熱交換器にドレンが生じない下限温度が高くなる。
【０００９】
そのため、前記ドレン防止温度を一定値とした場合には、前記ドレン防止温度を前記バーナの燃焼量を最小設定としたときに前記熱交換器にドレンが生じない温度に設定する必要がある。しかし、この場合には、前記バーナの燃焼量が該最小設定よりも大きいときは、実際にドレンが生じない下限温度よりも前記熱交換器の出湯温度が高くなるように、前記熱交流量制御手段によって前記熱交換器に供給される水の流量が制御される。その結果、前記熱交換器に供給される水の流量が、ドレンの発生を防止するために実際に必要な最小の流量よりも少なくなって、前記熱交換器の熱効率が最良のものとはならない。
【００１０】
そこで、本発明は、前記バーナの燃焼量と前記熱交換器にドレンが生じない下限温度との相関データを予め記憶した記憶手段と、前記相関データに基づいて、前記目標燃焼量に対応した前記下限温度付近に前記ドレン防止温度を設定するドレン防止温度設定手段とを備える。
【００１１】
そして、前記ドレン防止温度設定手段により、前記相関データに基づいて、前記目標燃焼量に対応した前記下限温度付近に前記ドレン防止温度が設定される。また、前記熱交温度センサの検出温度がこのようにして設定されたドレン防止温度となるように、前記熱交流量制御手段によって前記熱交換器に供給される水の流量が調節される。そのため、前記熱交換器にドレンが生じない範囲で前記熱交換器に供給される水の流量が極力大きくなるように制御がなされ、これにより前記熱交換器の熱効率を高めることができる。
【００１２】
そして、本発明の第１の態様は、前記熱交換器は給水管から供給される水を加熱して給湯管に出湯し、前記熱交換器をバイパスして該給水管と該給湯管とを連通するバイパス管と、前記熱交流量調節手段であって前記熱交換器を流れる水の流量と前記バイパス管を流れる水の流量との比であるバイパス比を調節するバイパス比調節手段と、前記給湯管と前記バイパス管との合流箇所の下流側に供給される湯の温度を検出する給湯温度センサを備え、前記目標燃焼量決定手段は、前記所定条件として、前記給湯温度センサの検出温度が所定の目標給湯温度と一致するように前記目標燃焼量を決定し、前記熱交流量制御手段は、前記バイパス比調節手段により前記バイパス比を変更することによって、前記熱交換器に供給される水の流量を調節することを特徴とする。
【００１３】
かかる本発明によれば、前記給水管から供給される水の流量を変更することなく、前記給湯管と前記バイパス管の合流箇所の下流側に前記目標給湯温度の湯が該流量で供給されるように前記バーナの燃焼量を制御する場合において、前記熱交流量制御手段は、前記バイパス比を変更して前記熱交換器に供給される水の流量を調節し、前記熱交換器の出湯温度を前記ドレン防止温度設定手段により設定されたドレン防止温度とすることによって、前記目標給湯温度での給湯を行なうときの前記熱交換器の熱効率を高めることができる。
【００１４】
また、本発明の第２の態様は、前記熱交換器は循環回路を介して浴槽と連通し、前記浴槽内の水を前記循環回路及び前記熱交換器を介して循環させるポンプと、前記浴槽内の湯の温度を検出する風呂温度センサと、前記熱交流量調節手段であって前記ポンプの送水流量を変更することにより前記循環回路内を循環する水の流量を調節する循環流量調節手段とを備え、前記目標燃焼量決定手段は、前記所定条件として、所定の目標追焚き温度と前記風呂温度センサの検出温度との差に応じて前記目標燃焼量を決定し、前記熱交流量制御手段は、前記循環流量調節手段により前記循環回路内を循環する水の流量を変更することによって、前記熱交換器に供給される水の流量を調節することを特徴とする。
【００１５】
かかる本発明によれば、前記浴槽内の湯を前記熱交換器を介して循環させることによって追焚きし、前記風呂温度センサの検出温度と前記目標給湯温度との差に応じて前記バーナの燃焼量を制御する場合において、前記熱交流量制御手段は、前記循環流量調節手段により前記熱交換器に供給される水の流量を調整して、前記熱交換器の出湯温度を前記ドレン防止温度設定手段により設定されたドレン防止温度とすることによって、前記浴槽内の湯を追焚きするときの前記熱交換器の熱効率を高めることができる。
【００１６】
また、本発明の第３の態様は、前記熱交換器は循環回路を介して暖房端末と連通し、前記熱交換器で加熱された水を前記循環回路を介して前記暖房端末に供給すると共に、前記暖房端末で放熱された水を前記熱交換器に回収するポンプと、前記熱交換器をバイパスして前記循環回路の上流側と下流側を連通するバイパス管と、前記熱交流量調節手段であって前記熱交換器を流れる水の流量と前記バイパス管を流れる水の流量との比であるバイパス比を調節するバイパス比調節手段と、前記循環回路と前記バイパス管との合流箇所の下流側に供給される湯の温度を検出する給湯温度センサとを備え、前記目標燃焼量決定手段は、前記所定条件として、前記給湯温度センサの検出温度が所定の目標給湯温度と一致するように前記目標燃焼量を決定し、前記熱交流量制御手段は、前記バイパス比調節手段により前記バイパス比を変更することによって前記熱交換器に供給される水の流量を調節することを特徴とする。
【００１７】
かかる本発明によれば、前記暖房端末に前記目標給湯温度の湯が供給されるように前記バーナの燃焼量を制御する場合において、前記熱交流量制御手段は、前記循環流量調節手段により前記熱交換器に供給される水の流量を調節して、前記熱交換器の出湯温度を前記ドレン防止温度設定手段により設定されたドレン防止温度とすることによって、前記暖房端末から放熱して暖房を行なうときの前記熱交換器の熱効率を高めることができる。
【００１８】
また、前記第１の態様から第３の態様において、前記バーナは複数のバーナブロックから構成され、前記記憶手段は、燃焼させるバーナブロックの組合わせ毎に、前記バーナの燃焼量と前記熱交換器にドレンが生じない下限温度との相関データを記憶し、前記ドレン防止温度設定手段は、燃焼中のバーナブロックの組合わせに応じた前記相関データを選択し、選択した該相関データに基づいて前記ドレン防止温度を設定することを特徴とする。
【００１９】
かかる本発明によれば、前記バーナが複数のバーナブロックにより構成され、燃焼させるバーナブロックの組合わせにより前記熱交換器の周囲を流れる燃焼排ガスの量や経路が変化する。そのため、燃焼させるバーナブロックの組合わせに応じて、前記バーナの燃焼量に応じた前記熱交換器にドレンが生じない下限温度も変化する。
【００２０】
そこで、燃焼させるバーナブロックの組合わせ毎に、前記バーナの燃焼量と前記熱交換器にドレンが生じない下限温度との相関データを前記記憶手段に記憶しておき、燃焼中のバーナブロックの組合わせに応じた該相関データを選択することによって、燃焼させるバーナブロックの組合わせに対応した前記ドレン防止温度を適切に設定することができる。
【００２１】
また、前記第１の態様から第３の態様において、前記ドレン防止温度設定手段は、前記バーナの点火がなされてから所定時間内は、前記ドレン防止温度を前記下限温度よりも所定温度以上高く設定することを特徴とする。
【００２２】
かかる本発明によれば、前記バーナの点火がなされた後、前記所定時間内は、前記ドレン防止温度設定手段により前記ドレン防止温度が前記下限温度よりも所定温度高く設定される。その結果、前記熱交流量制御手段により、前記熱交換器からの出湯温度を高くするために前記熱交換器に供給される水の流量を減少する制御がなされ、前記熱交換器に供給される水による吸熱量が減少して前記熱交換器を迅速に加熱することができる。そのため、前記バーナが点火された直後に、前記熱交換器の温度が低くドレンが生じやすい状態となる時間を短縮することができる。
【００２３】
【発明の実施の形態】
本発明の実施の形態について、図１〜図５を参照して説明する。図１は本発明の第１の実施の形態における追焚き機能付き給湯装置の全体構成図、図２〜図３は図１に示した給湯装置の作動フローチャート、図４は図１に示した給湯装置におけるバーナの燃焼量と熱交換器の熱効率の関係を示したグラフとバーナの燃焼量からドレン防止温度を決定するための相関マップを示した図、図５は本発明の第２の実施の形態における暖房熱源装置の全体構成図である。
【００２４】
先ず、図１〜図４を参照して第１の実施の形態について説明する。図１を参照して、本発明のフロー式水加熱装置である給湯装置１は、給水管２から供給される水を加熱して給湯管３に供給する給湯部４と、浴槽５内の水を追焚き循環回路６（追焚き往き管６ａ及び追焚き戻り管６ｂ、本発明の循環回路に相当する）を介して追焚きする追焚き部７とからなる。
【００２５】
給湯部４には、給水管２及び給湯管３と連通した給湯熱交換器１０（本発明の熱交換器に相当する）、給湯熱交換器１０を加熱する給湯バーナ１１（本発明のバーナに相当する）、給湯バーナ１１を点火するための給湯点火プラグ１２、給湯点火プラグ１２に高電圧を印加するイグナイタ１３、給湯バーナ１１の燃焼炎の有無を検知する給湯フレームロッド１４、給湯バーナ１１に燃焼用空気を供給する給湯燃焼ファン１５（本発明の燃焼量調節手段に相当する）、及び給湯熱交換器１０から出湯される湯の温度を検出する給湯熱交温度センサ１６（本発明の熱交温度センサに相当する）が備えられている。
【００２６】
なお、給湯バーナ１１は、第１バーナブロック１１ａ（本発明のバーナブロックに相当する）と第２バーナブロック１１ｂ（本発明のバーナブロックに相当する）により構成されている。
【００２７】
そして、給水管２には、給水流量を検出する給水流量センサ２０、給水温度を検出する給水温度センサ２１、給水流量を調節する給水サーボ弁２２が備えられている。また、給湯熱交換器１０をバイパスして給水管２と給湯管３を連通するバイパス管３０に、バイパス管３０の開度を調節するバイパスサーボ弁３１（本発明のバイパス比調節手段に相当する）が備えられ、給湯管３とバイパス管３０との合流箇所の下流に、給湯温度を検出する給湯温度センサ３２が備えられている。
【００２８】
さらに、給湯部４には、燃料ガスが供給されるガス供給管４０を開閉する元電磁弁４１、ガス供給管４０から分岐した給湯ガス管４２の開度を調節する給湯ガス比例弁４３（本発明の燃焼量調節手段に相当する）、給湯ガス管４２から第１バーナブロック１１ａへの燃料ガスの供給／遮断を切換える第１切換電磁弁４４ａ、及び給湯ガス管４２から第２バーナブロック１１ｂへの燃料ガスの供給／遮断を切換える第２切換電磁弁４４ｂが備えられている。
【００２９】
一方、追焚き部７には、追焚き循環回路６と連通した追焚き熱交換器５０（本発明の熱交換器に相当する）、追焚き熱交換器５０を加熱する追焚きバーナ５１（本発明のバーナに相当する）、追焚きバーナ５１を点火するための追焚き点火プラグ５２、追焚きバーナ５１の燃焼炎の有無を検知する追焚きフレームロッド５３、追焚きバーナ５１に燃焼用空気を供給する追焚き燃焼ファン５４、追焚き熱交換器５０から出湯される湯の温度を検出する追焚き熱交温度センサ５５（本発明の熱交温度センサに相当する）、浴槽５内の湯を追焚き循環回路６内に循環させるための追焚きポンプ５６（本発明のポンプに相当する）、追焚き循環回路６中の水の有無を検知する循環水流スイッチ５７、追焚き戻り管６ｂ内を流通する浴槽５内の湯の温度を検出する風呂温度センサ５８、及びガス供給管４０から分岐した追焚きガス管６０の開度を調節する追焚きガス比例弁６１が備えられている。
【００３０】
また、給湯管３を追焚き循環回路６と連通する湯張り中継管７０が設けられ、湯張り中継管７０の途中箇所に、湯張り中継管７０を開閉する湯張り中継弁７１と湯張り中継管７０を流れる湯の流量を検出する湯張り流量センサ７２が備えられている。
【００３１】
そして、マイクロコンピュータ等により構成されたコントローラ８０（本発明の目標燃焼量決定手段、燃焼量制御手段、熱交流量制御手段、記憶手段、及びドレン防止温度設定手段の機能を含む）によって、給湯装置１の作動が制御される。
【００３２】
コントローラ８０には、給湯装置１の運転／停止の指示や運転条件の設定を行なうと共に給湯装置１の運転状況等を表示するリモコン８１が接続され、リモコン８１からの各種の指示信号と、給湯フレームロッド１４、給湯熱交温度センサ１６、給水流量センサ２０、給水温度センサ２１、給湯温度センサ３２、追焚きフレームロッド５３、追焚き熱交温度センサ５５、循環水流スイッチ５７、風呂温度センサ５８、及び湯張り流量センサ７２からの検出信号とが入力される。
【００３３】
また、コントローラ８０から出力される制御信号によって、イグナイタ１３、給湯燃焼ファン１５、給水サーボ弁２２、バイパスサーボ弁３１、元電磁弁４１、給湯ガス比例弁４３、第１切換電磁弁４４ａ、第２切換電磁弁４４ｂ、追焚き燃焼ファン５４、追焚きポンプ５６、追焚きガス比例弁６１、及び湯張り中継弁７１の作動が制御される。
【００３４】
次に、コントローラ８０による給湯運転の実行手順について、図２〜図３に示したフローチャートに従って説明する。コントローラ８０は、給水流量センサ２０の検出信号により給水管２からの給水が開始されたことを検知すると、図２のＳＴＥＰ１からＳＴＥＰ２に進んで、給湯バーナ１１の点火処理を行なう。すなわち、給湯燃焼ファン１５を作動させ、イグナイタ１３により給湯点火プラグ１２に高電圧を印加して火花放電を生じさせた状態で、元電磁弁４１、給湯ガス比例弁４３、第１切換電磁弁４４ａ、及び第２切換電磁弁４４ｂを開弁して給湯バーナ１１に燃料ガスを供給し、給湯バーナ１１に点火する。
【００３５】
そして、コントローラ８０は、ＳＴＥＰ３で１分タイマをスタートする。この１分タイマは、後述するＳＴＥＰ２０の処理により、給湯バーナ１１の点火後１分間（本発明の所定時間に相当する）が経過するまでは、給湯熱交換器１０に供給される水の流量を減少させて、給湯熱交換器１０を速やかに加熱するためのものである。
【００３６】
次のＳＴＥＰ４で、コントローラ８０は、給水温度センサ２１により検出される給水管２からの給水温度と、給水流量センサ２０により検出される給水管２からの給水流量と、リモコン８１により設定された目標給湯温度とに応じて、該目標給湯温度の給湯が得られる給湯バーナ１１の目標燃焼量（Ｑa）を決定する。そして、給湯温度センサ３２により検出される実際の給湯温度が目標給湯温度と一致するように、給湯バーナ１１の目標燃焼量（Ｑa）を微調整する。
【００３７】
続くＳＴＥＰ５で、コントローラ８０は、給湯バーナ１１の燃焼量が目標燃焼量（Ｑa）となるように、給湯燃焼ファン１５の回転数を調節して給湯バーナ１１への燃焼用空気の供給流量を制御すると共に、給湯ガス比例弁４３により給湯ガス管４２の開度を調節して給湯バーナ１１への燃料ガスの供給流量を制御する。
【００３８】
なお、ＳＴＥＰ４が本発明の目標燃焼量決定手段による処理に相当し、ＳＴＥＰ５が本発明の燃焼制御手段による処理に相当する。
【００３９】
そして、次のＳＴＥＰ６で、コントローラ８０は、予めメモリ（図示しない、本発明の記憶手段に相当する）に記憶した、図４（ｂ）に示した目標燃焼量（Ｑa）とドレン防止温度（Ｔd）との相関関係を示した相関マップ（本発明の相関データに相当する。以下Ｑa／Ｔdマップという）に、ＳＴＥＰ４で決定した目標燃焼量（Ｑa）を適用して、該目標燃焼量（Ｑa）に対応したドレン防止温度（Ｔd）を得る。なお、ＳＴＥＰ６は本発明のドレン防止温度設定手段による処理に相当する。
【００４０】
図４（ｂ）に示したＱa／Ｔdマップは、予め実験により測定した目標燃焼量（Ｑa，横軸）と、該目標燃焼量（Ｑa）で給湯バーナ１１を燃焼させたときに、給湯熱交換器１０からドレンが発生しないようにするために必要な給湯熱交換器１０からの出湯温度の下限温度との相関データをマップ化したものであり、給湯熱交換器１０の固体差等を考慮して、測定された下限温度よりも若干（例えば２℃）高い温度にドレン防止温度（Ｔd）が設定されている。
【００４１】
コントローラ８０は、給湯熱交温度センサ１６の検出温度が、目標燃焼量（Ｑa）をＱa／Ｔdマップに適用して得られたドレン防止温度（Ｔd）以上となるように、給湯熱交換器１０に供給される水の流量を制御することによって、給湯熱交換器１０からドレンが発生し、該ドレンの付着により給湯熱交換器１０の劣化が生じることを防止することができる。
【００４２】
そして、図４（ｂ）中、▲１▼は第１給湯バーナ１１ａと第２給湯バーナ１１ｂの双方を燃焼させた場合（全燃焼）の相関マップを示し、▲２▼は第１給湯バーナ１１ａのみを燃焼させた場合（１／２燃焼）の相関マップを示している。図２（ｂ）に示したように、１／２燃焼の場合と全燃焼の場合とでは、目標燃焼量（Ｑa）におけるドレン防止温度が異なるため、１／２燃焼用のＱa／Ｔdマップ（▲２▼）と、全燃焼用のＱa／Ｔdマップ（▲１▼）を用意することによって、より精度良くドレン防止温度（Ｔd）を設定することができる。
【００４３】
また、ＳＴＥＰ７で１分タイマがタイムアップしていないとき（給湯バーナ１１の点火から１分が経過していないとき）は、ＳＴＥＰ２０に分岐し、コントローラ８０は、ドレン防止温度（Ｔd）を５℃高く設定する。これにより、給湯開始時に給湯熱交換器１０の温度が速やかに上昇するようにし、給湯開始後、給湯熱交換器１０の温度が低くドレンが生じやすい状態となる時間を短縮している。
【００４４】
また、図４（ａ）は、ある燃焼量で給湯バーナ１１を燃焼させた状態で給湯熱交換器１０に供給する水の流量を変化させたときの、給湯熱交換器１０からの出湯温度（Ｔout）と給湯熱交換器１０の熱効率（α）との関係を示したグラフである。図４（ａ）のグラフから明らかなように、給湯バーナ１１の燃焼量が一定であれば、給湯熱交換器１０に供給される水の流量を増やして給湯熱交換器１０からの出湯温度（Ｔout）を下げた方が、給湯熱交換器１０の熱効率（α）が高くなる。
【００４５】
そこで、図３のＳＴＥＰ８で、コントローラ８０は、給湯熱交温度センサ１６の検出温度がドレン防止温度（Ｔd）となるように、バイパスサーボ弁３１によりバイパス比を調節する。これにより、給湯バーナ１１の目標燃焼量（Ｑa）に対して、給湯熱交換器１０からドレンが生じない範囲で、給湯熱交換器１０に供給される水の流量を極力多くするように制御されるため、給湯熱交換器１０の熱効率をより良好なものとすることができる。なお、ＳＴＥＰ８は、本発明の熱交流量制御手段による処理に相当する。
【００４６】
そして、続くＳＴＥＰ９で、給水流量センサ２０により給水管２からの給水が検知されたときは図２のＳＴＥＰ４に戻って給湯運転を継続し、給水管２からの給水が検知されないときには、ＳＴＥＰ１０に進んで給湯バーナ１１の燃焼を停止し、給湯運転を終了して図２のＳＴＥＰ１に戻る。
【００４７】
次に、コントローラ８０は、リモコン８１により浴槽５への湯張り指示がなされたときは、湯張り中継弁７１を開弁して湯張り運転を開始する。
【００４８】
湯張り中継弁７１が開弁されると、給水管２からの給水が開始され、上述した給湯運転の場合と同様に、コントローラ８０は、給湯温度センサ３２の検出温度がリモコン８１により設定された目標湯張り温度となるように、給湯バーナ１１の目標燃焼量（Ｑa）を決定し、給湯熱交温度センサ１６の検出温度が目標燃焼量（Ｑa）をＱa／Ｔdマップに適用して設定したドレン防止温度（Ｔd）となるように、バイパスサーボ弁３１によりバイパス比を調節する。これにより、湯張り運転時の給湯熱交換器１０の熱効率をより良好なものとしている。
【００４９】
そして、コントローラ８０は、湯張り流量センサ７２の検出信号から浴槽５に供給された湯の累積量を算出し、該累積量がリモコン８１により設定された目標湯張り量に達したときに、湯張り中継弁７１を閉弁して湯張り運転を終了する。
【００５０】
次に、リモコン８１により追焚きの指示がなされたときは、コントローラ８０は追焚き運転を開始する。
【００５１】
追焚き運転においては、コントローラ８０は、追焚きポンプ５６（本発明のポンプに相当する）を作動させて浴槽５内の水を循環戻り管６ｂを介して追焚き熱交換器５０に供給し、追焚き熱交換器５０から出湯される湯を循環往き管６ａを介して浴槽５に戻すことにより、浴槽５内の水の追焚きを行なう。
【００５２】
コントローラ８０は、追焚き燃焼ファン５４を作動させ、イグナイタ１３により追焚き点火プラグ５２に火花放電を生じさせた状態で、元電磁弁４１と追焚きガス比例弁６１を開弁して追焚きバーナ５１に燃料ガスを供給し、追焚きバーナ５１に点火する。
【００５３】
そして、コントローラ８０は、先ず、追焚きバーナ５１の最大能力を目標燃焼量（Ｑa）として追焚きバーナ５１の燃焼量を制御し、風呂温度センサ５８の検出温度とリモコン８１により設定された目標追焚き温度との差が所定温度以下となった後は、追焚きバーナ５１の最大能力の１／２を目標燃焼量（Ｑa）として追焚きバーナ５１の燃焼量を制御する。
【００５４】
そして、浴槽温度センサ５８の検出温度が目標追焚き温度に達したときに、コントローラ８０は、元電磁弁４１と追焚きガス比例弁６１を閉弁して追焚きバーナ５１の燃焼を停止し、追焚き燃焼ファン５４と追焚きポンプ５６の作動を停止して追焚き運転を終了する。
【００５５】
ここで、コントローラ８０は、追焚きバーナ５１の最大能力における燃焼量に対応したドレン防止温度（Ｔd）と、最大能力の１／２における燃焼量に対応したドレン防止温度（Ｔd）のデータを予めメモリに記憶している。なお、この最大能力における燃焼量と最大能力の１／２における燃焼量に対応したドレン防止温度（Ｔd）のデータが本発明の相関データに相当し、ドレン防止温度（Ｔd）は、上述した給湯熱交換器１０における場合と同様に、予め実験等により決定される。
【００５６】
そして、コントローラ８０は、追焚き運転中、追焚き熱交温度センサ５５の検出温度が、追焚きバーナ５１の目標燃焼量（Ｑa）に応じたドレン防止温度（Ｔd）となるように、追焚きポンプ５６の送水量を調節して追焚き熱交換器５０に供給される水の流量を制御し、これにより追焚き熱交換器５０の熱効率をより良好なものとしている。
【００５７】
次に、図５を参照して、本発明の第２の実施の形態について説明する。本発明のフロー式水加熱装置である暖房熱源装置１００は、暖房循環回路１０１（暖房往き管１０１ａ，暖房戻り管１０１ｂ、本発明の循環回路に相当する）を介して床暖房端末１０２（本発明の暖房端末に相当する）と接続され、暖房循環回路１０１を介して床暖房端末１０２に湯を供給する。そして、これにより、床暖房端末１０２から放熱がなされる。
【００５８】
暖房熱源装置１００には、暖房循環回路１０１と連通した暖房熱交換器１１０、暖房熱交換器１１０を加熱する暖房バーナ１１１、暖房バーナ１１１を点火するための暖房点火プラグ１１２、暖房点火プラグ１１２に高電圧を印加するイグナイタ１１３、暖房バーナ１１１の燃焼炎の有無を検知する暖房フレームロッド１１４、暖房バーナ１１１に燃焼用空気を供給する暖房燃焼ファン１１５、及び暖房熱交換器１１０から出湯される湯の温度を検出する暖房熱交温度センサ１１６が備えられている。
【００５９】
また、暖房熱交換器１１０をバイパスして暖房往き管１０１ａと暖房戻り管１０１ｂを連通するバイパス管１２０には、バイパス管１２０の開度を調節するバイパスサーボ弁１２１が備えられ、暖房往き管１０１ａとバイパス管１２０との合流箇所の下流には、床暖房端末１０２に供給される湯の温度を検出する給湯温度センサ１２２が備えられている。
【００６０】
さらに、暖房熱源装置１００には、暖房循環回路１０１内に湯を循環させるための暖房ポンプ１２３（本発明のポンプに相当する）、燃料ガスが供給されるガス供給管１３０を開閉する元電磁弁１３１、ガス供給管１３０の開度を調節する暖房ガス比例弁１３２が備えられている。
【００６１】
そして、マイクロコンピュータ等により構成されたコントローラ１４０（本発明の目標燃焼量決定手段、燃焼量制御手段、熱交流量制御手段、記憶手段、ドレン防止温度設定手段の機能を含む）によって、暖房熱源装置１００の作動が制御される。
【００６２】
コントローラ１４０には、床暖房端末１０２の作動／停止の指示や暖房運転の条件設定を行なうと共に暖房熱源装置１００の運転状況等を表示するリモコン１４１が接続され、リモコン１４１からの各種の指示信号と、暖房フレームロッド１１４、暖房熱交温度センサ１１６、給湯温度センサ１２２、及びリモコン１４１に備えられた室温センサ１４２の検出信号とが入力される。
【００６３】
また、コントローラ１４０から出力される制御信号によって、イグナイタ１１３、暖房燃焼ファン１１５、元電磁弁１３１、暖房ガス比例弁１３２、バイパスサーボ弁１２１、及び暖房ポンプ１２３の作動が制御される。
【００６４】
コントローラ１４０は、リモコン１４１により暖房運転の開始が指示されたときに、暖房ポンプ１２３を作動させて暖房熱交換器１１０で加熱された水を暖房往き管１０１ａを介して床暖房端末１０２に送出すると共に、床暖房端末で放熱した水を暖房戻り管１０１ｂを介して暖房熱交換器１１０に回収する暖房運転を開始する。
【００６５】
コントローラ１４０は、先ず、暖房燃焼ファン１１５を作動させ、イグナイタ１１３により暖房点火プラグ１１２に火花放電を生じさせた状態で、元電磁弁１３１と暖房比例弁１３２を開弁して暖房バーナ１１１に燃料ガスを供給し、暖房バーナ１１１に点火する。
【００６６】
そして、コントローラ１４０は、給湯温度センサ１２２の検出温度が所定の給湯目標温度（例えば８０℃）となるように、暖房バーナ１１１の目標燃焼量（Ｑa）を決定し、暖房バーナ１１１の燃焼量が該目標燃焼量（Ｑa）となるように、暖房燃焼ファン１１５の回転数を調節して暖房バーナ１１１への燃焼用空気の供給流量を制御すると共に、暖房ガス比例弁１３２によりガス供給管１３０の開度を調節して暖房バーナ１１１への燃料ガスの供給流量を制御する。
【００６７】
また、コントローラ１４０は、暖房ポンプを１２３を作動させて、暖房熱交換器１１０で加熱された湯を暖房循環回路１０１を介して床暖房端末１０２に供給し、これにより床暖房端末１０２からの放熱によって床暖房装置１０２が設置された室内が暖房される。
【００６８】
ここで、コントローラ１４０のメモリ（図示しない）には、上述した第１の実施の形態におけるコントローラ８０と同様に、暖房バーナ１１１の目標燃焼量（Ｑa）から該目標燃焼量（Ｑa）に対応したドレン防止温度（Ｔd）を得るためのＱa／Ｔdマップが予め記憶されている。
【００６９】
そして、コントローラ１４０は、目標燃焼量（Ｑa）をＱa／Ｔdマップに適用して該目標燃焼量（Ｑa）に対応したドレン防止温度（Ｔd）を決定し、暖房熱交温度センサ１１６の検出温度が該ドレン防止温度（Ｔd）となるように、バイパスサーボ弁１２１の開度を調節して暖房熱交換器１１０に供給される湯の流量を制御する。
【００７０】
このように、暖房熱交換器１１０から出湯される湯の温度がドレン防止温度（Ｔd）となるように暖房熱交換器１１０に供給される水の流量を制御することによって、暖房運転時における暖房熱交換器１１０の熱効率をより良好なものとすることができる。
【００７１】
また、コントローラ１４０は、室温センサ１４２の検出温度がリモコン１４１により設定された目標室温を超えたときに暖房運転を中断し、室温センサ１４２の検出温度が該目標室温よりも所定温度（例えば２℃）下がったときに暖房運転を再開することによって、室内の温度がほぼ該目標室温となるようにする制御を行なう。
【００７２】
なお、前記第１及び第２の実施の形態においては、本発明の相関データとして、目標燃焼量（Ｑa）と実験等により決定した該目標燃焼量（Ｑa）における熱交換器からドレンが生じない下限温度よりも所定温度高く設定したドレン防止温度（Ｔd）との対応関係をマップ化したマップデータ（Ｑa／Ｔdマップ）を用いたが、目標燃焼量（Ｑa）と該目標燃焼量（Ｑa）における熱交換器からドレンが生じない下限温度との対応関係をマップ化したマップデータを本発明の相関データとして用い、該相関データに目標燃焼量（Ｑa）を適用して得られる該下限温度よりも所定温度高い温度をドレン防止温度（Ｔd）として設定するようにしてもよい。
【００７３】
また、前記第１及び第２の実施の形態においては、本発明の相関データとしてマップデータ（Ｑa／Ｔdマップ）を用いたが、目標燃焼量（Ｑa）を入力して該目標燃焼量（Ｑa）に対応したドレン防止温度（Ｔd）を出力する数式データを用いてもよい。
【００７４】
また、前記第１の実施の形態の給湯運転においては、熱交換器の加熱開始から所定時間が経過するまで、ドレン防止温度（Ｔd）を高く設定して熱交換器の温度を速やかに高める処理を行なったが、この処理を行なわない場合であっても本発明の効果を得ることができる。
【００７５】
また、前記第１の実施の形態の給湯運転における場合と同様に、前記第１の実施の形態の湯張り運転と追焚き運転、及び前記第２の実施の形態においても、熱交換器の加熱開始から所定時間が経過するまで、ドレン防止温度（Ｔd）を高く設定して熱交換器の温度を速やかに高める処理を行なってもよい。
【００７６】
また、前記第１の実施の形態では、第１バーナブロック１１ａと第２バーナブロック１１ｂという２個のバーナブロックからなる給湯バーナ１１を示したが、３個以上のバーナブロックにより給湯バーナを構成してもよい。この場合には、燃焼させるバーナブロックの組合わせ毎に、目標燃焼量（Ｑa）とドレン防止温度（Ｔd）との相関データを用意して予めメモリに記憶し、燃焼させるバーナブロックの組合わせに応じて選択した相関データに基づいてドレン防止温度を決定するようにしてもよい。
【００７７】
また、追焚きバーナ５１及び暖房バーナ１１１も、給湯バーナ１１と同様に、複数のバーナブロックにより構成してもよい。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態における追焚き機能付き給湯装置の全体構成図。
【図２】図１に示した給湯装置の作動フローチャート。
【図３】図１に示した給湯装置の作動フローチャート。
【図４】図１に示した給湯装置におけるバーナの燃焼量と熱交換器の熱効率との関係を示したグラフ及びバーナの燃焼量からドレン防止温度を決定するための相関マップを示した図。
【図５】本発明の第２の実施の形態における暖房熱源装置の全体構成図。
【符号の説明】
１…追焚き機能付き給湯装置、４…給湯部、７…追焚き部、１０…給湯熱交換器、１１…給湯バーナ、１５…給湯燃焼ファン、１６…給湯熱交温度センサ、３０…バイパス管、３１…バイパスサーボ弁３１、５０…追焚き熱交換器、５１…追焚きバーナ、５４…追焚き燃焼ファン、５５…追焚き熱交温度センサ、５６…追焚き循環ポンプ、１００…暖房熱源装置、１０３…床暖房端末、１１０…暖房熱交換器、１１１…暖房バーナ、１１５…暖房燃焼ファン、１１６…暖房熱交温度センサ、１２０…バイパス管、１２１…バイパスサーボ、１２３…暖房循環ポンプ、１４０…コントローラ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flow-type water heating apparatus that prevents drainage from being generated from a heat exchanger by maintaining the temperature of hot water from a heat exchanger at a predetermined temperature or higher.
[0002]
[Prior art]
Conventionally, as a flow-type water heating device, for example, a heat exchanger heated by a burner has been provided, and hot water having a predetermined target hot water supply temperature is obtained by heating water supplied from a water supply pipe using the heat exchanger. There is known a gas hot-water supply device that discharges water to a hot water supply pipe.
[0003]
In such a gas water heater, when the temperature of the hot water from the heat exchanger becomes low and the temperature of the combustion exhaust gas of the burner around the heat exchanger becomes low, the water vapor of the combustion exhaust gas becomes drain and adheres to the surface of the heat exchanger. To come. If the drain adheres in this way, the heat exchanger is corroded and the heat exchanger is deteriorated.
[0004]
Therefore, a bypass pipe that bypasses the heat exchanger and connects the water supply pipe and the hot water pipe and a ratio of the flow rate of water supplied to the bypass pipe to the flow rate of water supplied to the heat exchanger (bypass ratio) is adjusted. And a bypass servo valve for adjusting the bypass ratio so that the temperature of the hot water discharged from the heat exchanger becomes a predetermined drain prevention temperature so as not to generate drainage, and is supplied to the heat exchanger. A gas hot water supply device that controls the flow rate of water is proposed.
[0005]
And in the conventional gas hot-water supply apparatus, the said drain prevention temperature was set to the fixed value. However, the inventors of the present application, when controlling the flow rate of water supplied to the heat exchanger so that the tapping temperature of the heat exchanger becomes a constant drain prevention temperature, the heat efficiency of the heat exchanger is reduced. It was found that it was not necessarily good.
[0006]
[Problems to be solved by the invention]
An object of this invention is to provide the flow type water heating apparatus which improved the thermal efficiency of the heat exchanger, when restrict | limiting the tapping temperature from a heat exchanger in order to prevent generation | occurrence | production of a drain.
[0007]
[Means for Solving the Problems]
The present invention has been made to achieve the above-described object, and includes a heat exchanger that heats supplied water to generate hot water, a burner that heats the heat exchanger, and a combustion that adjusts the combustion amount of the burner. Amount adjusting means, target combustion amount determining means for determining a target combustion amount of the burner according to a predetermined condition, and combustion amount control means for controlling the combustion amount of the burner to the target combustion amount by the combustion amount adjusting means; A heat exchange temperature sensor for detecting the temperature of hot water discharged from the heat exchanger, a heat exchange amount adjusting means for adjusting a flow rate of water supplied to the heat exchanger, and a detection temperature of the heat exchange temperature sensor It is related with the improvement of the flow type water heating apparatus provided with the heat AC amount control means which adjusts the flow volume of the water supplied to the said heat exchanger by the said heat AC amount adjustment means so that it may become predetermined | prescribed drain prevention temperature.
[0008]
In such a flow-type water heating device, details will be described later, but when the burner combustion amount is constant, the flow rate of water supplied to the heat exchanger is increased to lower the tapping temperature of the heat exchanger. This increases the thermal efficiency of the heat exchanger. In addition, the smaller the burner combustion amount, the lower the temperature around the heat exchanger and the more likely the drain to be generated in the heat exchanger. Therefore, the lower limit temperature at which no heat is generated in the heat exchanger increases.
[0009]
Therefore, when the drain prevention temperature is set to a constant value, it is necessary to set the drain prevention temperature to a temperature at which no drainage is generated in the heat exchanger when the burner combustion amount is set to the minimum. However, in this case, when the combustion amount of the burner is larger than the minimum setting, the heat AC amount control is performed so that the tapping temperature of the heat exchanger becomes higher than the lower limit temperature at which no drain is actually generated. The flow rate of water supplied to the heat exchanger is controlled by the means. As a result, the flow rate of water supplied to the heat exchanger is less than the minimum flow rate actually required to prevent drain generation, and the heat efficiency of the heat exchanger is not optimal. .
[0010]
  Therefore, the present invention provides a storage means that stores in advance correlation data between the burn amount of the burner and a lower limit temperature at which no drainage is generated in the heat exchanger, and the corresponding to the target combustion amount based on the correlation data. A drain prevention temperature setting means for setting the drain prevention temperature near the lower limit temperature.The
[0011]
  AndThe drain prevention temperature setting means sets the drain prevention temperature near the lower limit temperature corresponding to the target combustion amount based on the correlation data.Also,The flow rate of water supplied to the heat exchanger is adjusted by the thermal AC amount control means so that the temperature detected by the heat exchange temperature sensor becomes the drain prevention temperature set in this way. Therefore, control is performed so that the flow rate of water supplied to the heat exchanger is as large as possible within a range in which no drain is generated in the heat exchanger, and thereby the thermal efficiency of the heat exchanger can be increased.
[0012]
  The first aspect of the present invention isThe heat exchanger heats water supplied from a water supply pipe to discharge the hot water to the hot water supply pipe, bypasses the heat exchanger and connects the water supply pipe and the hot water supply pipe, and the heat exchange amount A bypass ratio adjusting means for adjusting a bypass ratio, which is a ratio of a flow rate of water flowing through the heat exchanger and a flow rate of water flowing through the bypass pipe, and a joining point of the hot water supply pipe and the bypass pipe A hot water supply temperature sensor for detecting the temperature of hot water supplied downstream of the hot water supply temperature sensor, and the target combustion amount determining means, as the predetermined condition, so that the temperature detected by the hot water supply temperature sensor coincides with a predetermined target hot water supply temperature. The target combustion amount is determined, and the thermal AC amount control means adjusts a flow rate of water supplied to the heat exchanger by changing the bypass ratio by the bypass ratio adjusting means. .
[0013]
According to the present invention, hot water having the target hot water supply temperature is supplied at the flow rate downstream of the joining point of the hot water supply pipe and the bypass pipe without changing the flow rate of water supplied from the water supply pipe. Thus, when controlling the combustion amount of the burner, the thermal AC amount control means adjusts the flow rate of water supplied to the heat exchanger by changing the bypass ratio, and the hot water temperature of the heat exchanger By making the drain prevention temperature set by the drain prevention temperature setting means, the thermal efficiency of the heat exchanger when performing hot water supply at the target hot water supply temperature can be increased.
[0014]
  Also,The second aspect of the present invention is:The heat exchanger communicates with the bathtub via a circulation circuit, a pump that circulates water in the bathtub via the circulation circuit and the heat exchanger, and a bath temperature sensor that detects the temperature of hot water in the bathtub And a circulation flow rate adjusting means for adjusting the flow rate of water circulating in the circulation circuit by changing the water supply flow rate of the pump, the target combustion amount determining means, As the predetermined condition, the target combustion amount is determined according to a difference between a predetermined target reheating temperature and a temperature detected by the bath temperature sensor, and the thermal AC amount control means is configured to be connected to the circulation circuit by the circulation flow rate adjustment means. The flow rate of water supplied to the heat exchanger is adjusted by changing the flow rate of water circulating inside.
[0015]
According to the present invention, the hot water in the bathtub is circulated by circulating it through the heat exchanger, and the burner burns according to the difference between the temperature detected by the bath temperature sensor and the target hot water temperature. In the case of controlling the amount, the thermal AC amount control means adjusts the flow rate of water supplied to the heat exchanger by the circulation flow rate adjusting means, and sets the tapping temperature of the heat exchanger to the drain prevention temperature setting. By setting it as the drain prevention temperature set by the means, the thermal efficiency of the heat exchanger when chasing hot water in the bathtub can be increased.
[0016]
  Also,The third aspect of the present invention is:The heat exchanger communicates with a heating terminal via a circulation circuit, supplies water heated by the heat exchanger to the heating terminal via the circulation circuit, and releases water radiated from the heating terminal. A pump to be recovered in the heat exchanger, a bypass pipe that bypasses the heat exchanger and communicates the upstream side and the downstream side of the circulation circuit, and the heat exchange amount adjusting means that is water flowing through the heat exchanger A bypass ratio adjusting means for adjusting a bypass ratio, which is a ratio between a flow rate and a flow rate of water flowing through the bypass pipe, and a temperature of hot water supplied to a downstream side of a junction between the circulation circuit and the bypass pipe; A hot water supply temperature sensor, and the target combustion amount determination means determines the target combustion amount so that the detected temperature of the hot water supply temperature sensor matches a predetermined target hot water supply temperature as the predetermined condition, and the thermal AC amount The control means And adjusting the flow rate of water supplied to the heat exchanger by changing the bypass ratio by serial bypass ratio adjustment means.
[0017]
According to the present invention, in the case of controlling the combustion amount of the burner so that hot water at the target hot water supply temperature is supplied to the heating terminal, the thermal AC amount control means is configured to control the heat flow by the circulation flow rate adjustment means. By adjusting the flow rate of water supplied to the exchanger and setting the tapping temperature of the heat exchanger to the drain prevention temperature set by the drain prevention temperature setting means, heat is radiated from the heating terminal for heating. The heat efficiency of the heat exchanger can be increased.
[0018]
  Also,In the first aspect to the third aspect,The burner is composed of a plurality of burner blocks, and the storage means stores correlation data between the burner burn amount and the lower limit temperature at which no heat is generated in the heat exchanger, for each combination of burner blocks to be burned. The drain prevention temperature setting means selects the correlation data corresponding to a combination of burner blocks during combustion, and sets the drain prevention temperature based on the selected correlation data.
[0019]
According to the present invention, the burner is composed of a plurality of burner blocks, and the amount and path of the combustion exhaust gas flowing around the heat exchanger changes depending on the combination of burner blocks to be burned. Therefore, according to the combination of burner blocks to be burned, the lower limit temperature at which no drain is generated in the heat exchanger corresponding to the burner combustion amount also changes.
[0020]
Therefore, for each combination of burner blocks to be burned, correlation data between the burner combustion amount and the lower limit temperature at which no heat is generated in the heat exchanger is stored in the storage means, and the set of burner blocks being burned is stored. By selecting the correlation data according to the combination, the drain prevention temperature corresponding to the combination of burner blocks to be burned can be set appropriately.
[0021]
  Also,In the first aspect to the third aspect,The drain prevention temperature setting means sets the drain prevention temperature higher than the lower limit temperature by a predetermined temperature within a predetermined time after the burner is ignited.
[0022]
According to the present invention, after the burner is ignited, the drain prevention temperature setting means sets the drain prevention temperature higher than the lower limit temperature by the drain prevention temperature setting means within the predetermined time. As a result, the flow rate of water supplied to the heat exchanger is reduced by the heat AC amount control means so as to increase the temperature of the tapping water from the heat exchanger, and is supplied to the heat exchanger. The amount of heat absorbed by water is reduced and the heat exchanger can be heated quickly. Therefore, immediately after the burner is ignited, it is possible to reduce the time during which the temperature of the heat exchanger is low and the drain is likely to be generated.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to FIGS. 1 is an overall configuration diagram of a hot water supply apparatus with a reheating function according to the first embodiment of the present invention, FIGS. 2 to 3 are operational flowcharts of the hot water supply apparatus shown in FIG. 1, and FIG. 4 is a hot water supply shown in FIG. FIG. 5 is a graph showing the relationship between the burner combustion amount and the heat efficiency of the heat exchanger in the apparatus, and a correlation map for determining the drain prevention temperature from the burner combustion amount. FIG. 5 shows the second embodiment of the present invention. It is a whole block diagram of the heating-heat-source apparatus in a form.
[0024]
First, a first embodiment will be described with reference to FIGS. Referring to FIG. 1, a hot water supply device 1 which is a flow-type water heating device of the present invention heats water supplied from a water supply pipe 2 and supplies the hot water supply pipe 3 with water, and water in a bathtub 5. And a chasing section 7 for chasing through the chasing circulation circuit 6 (the chasing return pipe 6a and the chasing return pipe 6b, which corresponds to the circulation circuit of the present invention).
[0025]
The hot water supply unit 4 includes a hot water supply heat exchanger 10 (corresponding to a heat exchanger of the present invention) communicated with the water supply pipe 2 and the hot water supply pipe 3, and a hot water supply burner 11 for heating the hot water supply heat exchanger 10 (to the burner of the present invention). The hot water supply spark plug 12 for igniting the hot water supply burner 11, the igniter 13 for applying a high voltage to the hot water supply spark plug 12, the hot water supply frame rod 14 for detecting the presence or absence of a combustion flame in the hot water supply burner 11, and the hot water supply burner 11. A hot water supply combustion fan 15 for supplying combustion air (corresponding to the combustion amount adjusting means of the present invention) and a hot water supply heat exchanger temperature sensor 16 for detecting the temperature of hot water discharged from the hot water heat exchanger 10 (heat of the present invention) Corresponding to the alternating temperature sensor).
[0026]
The hot water supply burner 11 includes a first burner block 11a (corresponding to the burner block of the present invention) and a second burner block 11b (corresponding to the burner block of the present invention).
[0027]
The water supply pipe 2 is provided with a water supply flow rate sensor 20 for detecting the water supply flow rate, a water supply temperature sensor 21 for detecting the water supply temperature, and a water supply servo valve 22 for adjusting the water supply flow rate. Further, a bypass servo valve 31 for adjusting the opening degree of the bypass pipe 30 (corresponding to the bypass ratio adjusting means of the present invention) is connected to the bypass pipe 30 that bypasses the hot water supply heat exchanger 10 and communicates the water supply pipe 2 and the hot water supply pipe 3. ) And a hot water supply temperature sensor 32 for detecting the hot water supply temperature is provided downstream of the joining point of the hot water supply pipe 3 and the bypass pipe 30.
[0028]
In addition, the hot water supply unit 4 includes an original electromagnetic valve 41 that opens and closes a gas supply pipe 40 to which fuel gas is supplied, and a hot water supply gas proportional valve 43 that adjusts the opening degree of a hot water supply gas pipe 42 branched from the gas supply pipe 40 (main (Corresponding to the combustion amount adjusting means of the invention), the first switching electromagnetic valve 44a for switching the supply / cutoff of the fuel gas from the hot water supply gas pipe 42 to the first burner block 11a, and the hot water supply gas pipe 42 to the second burner block 11b. A second switching electromagnetic valve 44b for switching between supply / cutoff of the fuel gas is provided.
[0029]
On the other hand, the reheating section 7 includes a reheating heat exchanger 50 (corresponding to the heat exchanger of the present invention) communicating with the recirculation circuit 6, and a reheating burner 51 for heating the reheating heat exchanger 50. (Corresponding to the burner of the present invention), a flare spark plug 52 for igniting the flare burner 51, a flare frame rod 53 for detecting the presence or absence of a combustion flame in the flare burner 51, and combustion air to the flare burner 51. The reheating combustion fan 54 to be supplied, the reheating heat exchanger temperature sensor 55 (corresponding to the heat exchanger temperature sensor of the present invention) for detecting the temperature of hot water discharged from the reheating heat exchanger 50, and hot water in the bathtub 5 are used. A recirculation pump 56 for circulation in the recirculation circuit 6 (corresponding to the pump of the present invention), a circulating water flow switch 57 for detecting the presence or absence of water in the recirculation circuit 6, and a recirculation return pipe 6b. Temperature of hot water in the circulating bath 5 Bath temperature sensor 58, and reheating the gas proportional valve 61 for adjusting the opening degree of reheating the gas pipe 60 branched from the gas supply pipe 40 is provided to detect.
[0030]
Further, a hot water relay pipe 70 is provided to connect the hot water supply pipe 3 and communicate with the circulation circuit 6. A hot water flow rate sensor 72 for detecting the flow rate of hot water flowing through the pipe 70 is provided.
[0031]
The controller 80 (including the functions of the target combustion amount determination means, the combustion amount control means, the thermal AC amount control means, the storage means, and the drain prevention temperature setting means) of the present invention is configured by a microcomputer or the like. The operation of 1 is controlled.
[0032]
The controller 80 is connected to a remote controller 81 for instructing operation / stop of the hot water supply apparatus 1 and setting operation conditions and displaying the operation status of the hot water supply apparatus 1. Various instruction signals from the remote control 81 and a hot water supply frame are connected. Rod 14, hot water heat exchange temperature sensor 16, water supply flow rate sensor 20, water supply temperature sensor 21, hot water supply temperature sensor 32, reheating frame rod 53, reheating heat exchange temperature sensor 55, circulating water flow switch 57, bath temperature sensor 58, and A detection signal from the hot water flow sensor 72 is input.
[0033]
Further, according to a control signal output from the controller 80, the igniter 13, the hot water combustion fan 15, the water servo valve 22, the bypass servo valve 31, the original solenoid valve 41, the hot water proportional valve 43, the first switching solenoid valve 44a, the second The operations of the switching electromagnetic valve 44b, the additional combustion fan 54, the additional pump 56, the additional gas proportional valve 61, and the hot water relay valve 71 are controlled.
[0034]
Next, the execution procedure of the hot water supply operation by the controller 80 will be described according to the flowcharts shown in FIGS. When the controller 80 detects from the detection signal of the feed water flow rate sensor 20 that water supply from the water supply pipe 2 has started, the controller 80 proceeds from STEP 1 to STEP 2 in FIG. 2 and performs the ignition process of the hot water supply burner 11. That is, the hot water supply combustion fan 15 is operated, and a high voltage is applied to the hot water supply spark plug 12 by the igniter 13 to cause a spark discharge, so that the original solenoid valve 41, the hot water supply gas proportional valve 43, the first switching solenoid valve 44a. And the 2nd switching solenoid valve 44b is opened, fuel gas is supplied to the hot water supply burner 11, and the hot water supply burner 11 is ignited.
[0035]
Then, the controller 80 starts a one minute timer at STEP3. This 1-minute timer controls the flow rate of water supplied to the hot water supply heat exchanger 10 until one minute (corresponding to the predetermined time of the present invention) elapses after ignition of the hot water supply burner 11 by the processing of STEP 20 described later. It is for decreasing and heating the hot water supply heat exchanger 10 rapidly.
[0036]
In the next STEP 4, the controller 80 detects the feed water temperature from the feed water pipe 2 detected by the feed water temperature sensor 21, the feed water flow rate from the feed water pipe 2 detected by the feed water flow sensor 20, and the target set by the remote controller 81. In accordance with the hot water supply temperature, the target combustion amount (Qa) of the hot water supply burner 11 for obtaining hot water supply at the target hot water supply temperature is determined. Then, the target combustion amount (Qa) of the hot water supply burner 11 is finely adjusted so that the actual hot water temperature detected by the hot water temperature sensor 32 matches the target hot water temperature.
[0037]
In subsequent STEP 5, the controller 80 controls the flow rate of the combustion air supplied to the hot water burner 11 by adjusting the rotational speed of the hot water combustion fan 15 so that the combustion amount of the hot water burner 11 becomes the target combustion amount (Qa). At the same time, the opening amount of the hot water supply gas pipe 42 is adjusted by the hot water supply gas proportional valve 43 to control the flow rate of the fuel gas supplied to the hot water supply burner 11.
[0038]
STEP 4 corresponds to the processing by the target combustion amount determining means of the present invention, and STEP 5 corresponds to the processing by the combustion control means of the present invention.
[0039]
Then, in the next STEP 6, the controller 80 stores the target combustion amount (Qa) and the drain prevention temperature (Td) shown in FIG. 4 (b) stored in advance in a memory (not shown, corresponding to the storage means of the present invention). The target combustion amount (Qa) determined in STEP 4 is applied to a correlation map (corresponding to the correlation data of the present invention, hereinafter referred to as Qa / Td map) indicating the correlation with the target combustion amount (Qa). ) To obtain a drain prevention temperature (Td). STEP 6 corresponds to the processing by the drain prevention temperature setting means of the present invention.
[0040]
The Qa / Td map shown in FIG. 4B shows the target combustion amount (Qa, horizontal axis) measured in advance by experiment and the hot water supply heat when the hot water supply burner 11 is burned at the target combustion amount (Qa). This is a map of correlation data with the lower limit temperature of the hot water supply temperature from the hot water supply heat exchanger 10 necessary for preventing drain from being generated from the exchanger 10, taking into account the individual differences of the hot water supply heat exchanger 10, etc. The drain prevention temperature (Td) is set to a temperature slightly higher (for example, 2 ° C.) than the measured lower limit temperature.
[0041]
The controller 80 controls the hot water supply heat exchanger 10 so that the temperature detected by the hot water supply heat exchange temperature sensor 16 is equal to or higher than the drain prevention temperature (Td) obtained by applying the target combustion amount (Qa) to the Qa / Td map. By controlling the flow rate of the water supplied to the hot water, it is possible to prevent drainage from the hot water supply heat exchanger 10 and deterioration of the hot water supply heat exchanger 10 due to the adhesion of the drain.
[0042]
In FIG. 4B, (1) shows a correlation map when both the first hot water supply burner 11a and the second hot water supply burner 11b are burned (total combustion), and (2) shows the first hot water supply burner 11a. The correlation map in the case of burning only (1/2 combustion) is shown. As shown in FIG. 2B, since the drain prevention temperature at the target combustion amount (Qa) differs between the case of 1/2 combustion and the case of full combustion, the Qa / Td map for 1/2 combustion ( By preparing (2)) and the Qa / Td map (1) for all combustion, the drain prevention temperature (Td) can be set with higher accuracy.
[0043]
Further, when the one-minute timer has not expired in STEP 7 (when one minute has not elapsed since the ignition of the hot water supply burner 11), the process branches to STEP 20, and the controller 80 sets the drain prevention temperature (Td) to 5 ° C. Set high. Thus, the temperature of the hot water supply heat exchanger 10 is quickly increased at the start of hot water supply, and the time during which the temperature of the hot water supply heat exchanger 10 is low and drain is likely to occur after the start of hot water supply is shortened.
[0044]
FIG. 4A shows the temperature of hot water discharged from the hot water supply heat exchanger 10 when the flow rate of water supplied to the hot water supply heat exchanger 10 is changed in a state where the hot water supply burner 11 is burned at a certain combustion amount (FIG. It is the graph which showed the relationship between Tout) and the thermal efficiency ((alpha)) of the hot water supply heat exchanger 10. FIG. As is clear from the graph of FIG. 4A, if the combustion amount of the hot water supply burner 11 is constant, the flow rate of water supplied to the hot water supply heat exchanger 10 is increased to increase the temperature of hot water discharged from the hot water supply heat exchanger 10 ( Lowering Tout) increases the thermal efficiency (α) of the hot water supply heat exchanger 10.
[0045]
Therefore, in STEP 8 of FIG. 3, the controller 80 adjusts the bypass ratio by the bypass servo valve 31 so that the temperature detected by the hot water supply heat exchange temperature sensor 16 becomes the drain prevention temperature (Td). Thus, the flow rate of water supplied to the hot water supply heat exchanger 10 is controlled as much as possible with respect to the target combustion amount (Qa) of the hot water supply burner 11 within a range where no drainage is generated from the hot water supply heat exchanger 10. Therefore, the thermal efficiency of the hot water supply heat exchanger 10 can be made better. Note that STEP 8 corresponds to processing by the thermal AC amount control means of the present invention.
[0046]
In subsequent STEP 9, when water supply from the water supply pipe 2 is detected by the water supply flow rate sensor 20, the process returns to STEP 4 in FIG. 2 to continue the hot water supply operation, and when water supply from the water supply pipe 2 is not detected, the process proceeds to STEP 10. Then, the combustion of the hot water supply burner 11 is stopped, the hot water supply operation is terminated, and the process returns to STEP 1 in FIG.
[0047]
Next, when the remote controller 81 gives a hot water filling instruction to the bathtub 5, the controller 80 opens the hot water filling relay valve 71 and starts the hot water filling operation.
[0048]
When the hot water filling relay valve 71 is opened, water supply from the water supply pipe 2 is started, and the controller 80 sets the temperature detected by the hot water supply temperature sensor 32 by the remote controller 81 as in the case of the hot water supply operation described above. The target combustion amount (Qa) of the hot water supply burner 11 is determined so as to be the target hot water filling temperature, and the detected temperature of the hot water supply heat exchange temperature sensor 16 is set by applying the target combustion amount (Qa) to the Qa / Td map. The bypass servo valve 31 adjusts the bypass ratio so that the drain prevention temperature (Td) is reached. Thereby, the thermal efficiency of the hot water supply heat exchanger 10 during hot water filling operation is improved.
[0049]
Then, the controller 80 calculates the cumulative amount of hot water supplied to the bathtub 5 from the detection signal of the hot water flow rate sensor 72, and when the cumulative amount reaches the target hot water amount set by the remote controller 81, The tension relay valve 71 is closed to end the hot water filling operation.
[0050]
Next, when the remote control 81 gives an instruction for chasing, the controller 80 starts chasing operation.
[0051]
In the chasing operation, the controller 80 operates the chasing pump 56 (corresponding to the pump of the present invention) to supply the water in the bathtub 5 to the chasing heat exchanger 50 via the circulation return pipe 6b. The hot water discharged from the reheating heat exchanger 50 is returned to the bathtub 5 through the circulation pipe 6a, thereby repurposing the water in the bathtub 5.
[0052]
The controller 80 operates the additional combustion fan 54 and opens the original solenoid valve 41 and the additional gas proportional valve 61 with the igniter 13 causing a spark discharge in the additional ignition plug 52 to open the additional burner. Fuel gas is supplied to 51 and the burner 51 is ignited.
[0053]
The controller 80 first controls the combustion amount of the additional burner 51 with the maximum capacity of the additional burner 51 as the target combustion amount (Qa), and detects the detected temperature of the bath temperature sensor 58 and the target additional amount set by the remote controller 81. After the difference from the burning temperature becomes equal to or lower than the predetermined temperature, the combustion amount of the additional burner 51 is controlled with 1/2 of the maximum capacity of the additional burner 51 as a target combustion amount (Qa).
[0054]
When the temperature detected by the bathtub temperature sensor 58 reaches the target reheating temperature, the controller 80 closes the original solenoid valve 41 and the reheating gas proportional valve 61 to stop the combustion of the reheating burner 51, The operation of the additional combustion fan 54 and the additional pump 56 is stopped and the additional operation is terminated.
[0055]
Here, the controller 80 previously stores data on the drain prevention temperature (Td) corresponding to the combustion amount at the maximum capacity of the additional burner 51 and the drain prevention temperature (Td) corresponding to the combustion amount at ½ of the maximum capacity. Stored in memory. Note that the data on the drain prevention temperature (Td) corresponding to the combustion amount at the maximum capacity and the combustion quantity at ½ of the maximum capacity corresponds to the correlation data of the present invention, and the drain prevention temperature (Td) is the hot water supply described above. As in the case of the heat exchanger 10, it is determined in advance by experiments or the like.
[0056]
Then, the controller 80 performs reheating so that the temperature detected by the reheating heat exchanger temperature sensor 55 becomes the drain prevention temperature (Td) corresponding to the target combustion amount (Qa) of the reheating burner 51 during reheating operation. The flow rate of water supplied to the follow-up heat exchanger 50 is controlled by adjusting the amount of water supplied by the pump 56, thereby making the heat efficiency of the follow-up heat exchanger 50 better.
[0057]
Next, a second embodiment of the present invention will be described with reference to FIG. A heating heat source apparatus 100 which is a flow type water heating apparatus of the present invention has a floor heating terminal 102 (the present invention) via a heating circulation circuit 101 (corresponding to the heating forward pipe 101a, the heating return pipe 101b and the circulation circuit of the present invention). The hot water is supplied to the floor heating terminal 102 via the heating circulation circuit 101. Thereby, heat is radiated from the floor heating terminal 102.
[0058]
The heating heat source device 100 includes a heating heat exchanger 110 that communicates with the heating circulation circuit 101, a heating burner 111 that heats the heating heat exchanger 110, a heating spark plug 112 that ignites the heating burner 111, and a heating spark plug 112. An igniter 113 that applies high voltage, a heating frame rod 114 that detects the presence or absence of a combustion flame in the heating burner 111, a heating combustion fan 115 that supplies combustion air to the heating burner 111, and hot water discharged from the heating heat exchanger 110 A heating heat exchange temperature sensor 116 for detecting the temperature of the heating is provided.
[0059]
The bypass pipe 120 that bypasses the heating heat exchanger 110 and connects the heating forward pipe 101a and the heating return pipe 101b is provided with a bypass servo valve 121 that adjusts the opening degree of the bypass pipe 120, and the heating forward pipe 101a. A hot water supply temperature sensor 122 that detects the temperature of hot water supplied to the floor heating terminal 102 is provided downstream of the junction with the bypass pipe 120.
[0060]
Further, the heating heat source device 100 includes a heating pump 123 (which corresponds to the pump of the present invention) for circulating hot water in the heating circulation circuit 101, and an original solenoid valve for opening and closing a gas supply pipe 130 to which fuel gas is supplied. 131, a heating gas proportional valve 132 for adjusting the opening of the gas supply pipe 130 is provided.
[0061]
A heating heat source apparatus is configured by a controller 140 (including the functions of a target combustion amount determining means, a combustion amount control means, a thermal AC amount control means, a storage means, and a drain prevention temperature setting means) according to the present invention. 100 operations are controlled.
[0062]
The controller 140 is connected to a remote controller 141 for instructing the operation / stop of the floor heating terminal 102 and setting the heating operation conditions, and displaying the operation status of the heating heat source device 100 and the like. The heating frame rod 114, the heating heat exchanger temperature sensor 116, the hot water supply temperature sensor 122, and the detection signal of the room temperature sensor 142 provided in the remote controller 141 are input.
[0063]
The operation of the igniter 113, the heating combustion fan 115, the original electromagnetic valve 131, the heating gas proportional valve 132, the bypass servo valve 121, and the heating pump 123 is controlled by a control signal output from the controller 140.
[0064]
When the start of the heating operation is instructed by the remote controller 141, the controller 140 operates the heating pump 123 and sends the water heated by the heating heat exchanger 110 to the floor heating terminal 102 via the heating forward pipe 101a. At the same time, the heating operation for collecting the water radiated from the floor heating terminal to the heating heat exchanger 110 via the heating return pipe 101b is started.
[0065]
First, the controller 140 operates the heating combustion fan 115 and opens the original electromagnetic valve 131 and the heating proportional valve 132 in a state where spark discharge is generated in the heating spark plug 112 by the igniter 113 and fuel is supplied to the heating burner 111. Gas is supplied and the heating burner 111 is ignited.
[0066]
Then, the controller 140 determines the target combustion amount (Qa) of the heating burner 111 so that the temperature detected by the hot water supply temperature sensor 122 becomes a predetermined hot water supply target temperature (for example, 80 ° C.). The number of revolutions of the heating combustion fan 115 is adjusted so as to achieve the target combustion amount (Qa) to control the supply flow rate of the combustion air to the heating burner 111, and the heating gas proportional valve 132 allows the gas supply pipe 130 to The fuel gas supply flow rate to the heating burner 111 is controlled by adjusting the opening.
[0067]
In addition, the controller 140 operates the heating pump 123 to supply hot water heated by the heating heat exchanger 110 to the floor heating terminal 102 via the heating circulation circuit 101, thereby radiating heat from the floor heating terminal 102. Thus, the room where the floor heating device 102 is installed is heated.
[0068]
Here, the memory (not shown) of the controller 140 corresponds to the target combustion amount (Qa) from the target combustion amount (Qa) of the heating burner 111, similarly to the controller 80 in the first embodiment described above. A Qa / Td map for obtaining the drain prevention temperature (Td) is stored in advance.
[0069]
Then, the controller 140 determines the drain prevention temperature (Td) corresponding to the target combustion amount (Qa) by applying the target combustion amount (Qa) to the Qa / Td map, and detects the temperature detected by the heating heat exchanger temperature sensor 116. Is adjusted to the drain prevention temperature (Td), the opening degree of the bypass servo valve 121 is adjusted to control the flow rate of hot water supplied to the heating heat exchanger 110.
[0070]
Thus, by controlling the flow rate of the water supplied to the heating heat exchanger 110 so that the temperature of the hot water discharged from the heating heat exchanger 110 becomes the drain prevention temperature (Td), the heating during the heating operation is performed. The heat efficiency of the heat exchanger 110 can be made better.
[0071]
Further, the controller 140 interrupts the heating operation when the temperature detected by the room temperature sensor 142 exceeds the target room temperature set by the remote controller 141, and the temperature detected by the room temperature sensor 142 is higher than the target room temperature by a predetermined temperature (for example, 2 ° C.). ) Control is performed so that the room temperature becomes approximately the target room temperature by restarting the heating operation when the temperature falls.
[0072]
In the first and second embodiments, as the correlation data of the present invention, no drain is generated from the heat exchanger at the target combustion amount (Qa) determined by experiments and the target combustion amount (Qa). Map data (Qa / Td map) that maps the correspondence relationship with the drain prevention temperature (Td) set higher than the lower limit temperature by a predetermined temperature was used. The target combustion amount (Qa) and the target combustion amount (Qa) From the lower limit temperature obtained by applying the map data corresponding to the lower limit temperature at which no drainage is generated from the heat exchanger in the present invention as the correlation data of the present invention and applying the target combustion amount (Qa) to the correlation data Alternatively, a temperature higher by a predetermined temperature may be set as the drain prevention temperature (Td).
[0073]
In the first and second embodiments, the map data (Qa / Td map) is used as the correlation data of the present invention. However, the target combustion amount (Qa) is input by inputting the target combustion amount (Qa). Formula data that outputs a drain prevention temperature (Td) corresponding to) may be used.
[0074]
In the hot water supply operation of the first embodiment, the drain prevention temperature (Td) is set high and the temperature of the heat exchanger is quickly increased until a predetermined time has elapsed from the start of heating of the heat exchanger. However, even if this process is not performed, the effects of the present invention can be obtained.
[0075]
Further, similarly to the case of the hot water supply operation of the first embodiment, the heating of the heat exchanger is also performed in the hot water filling operation and the reheating operation of the first embodiment and the second embodiment. Until the predetermined time elapses from the start, the drain prevention temperature (Td) may be set high, and the heat exchanger temperature may be quickly increased.
[0076]
In the first embodiment, the hot water supply burner 11 including two burner blocks, ie, the first burner block 11a and the second burner block 11b is shown. However, the hot water supply burner is constituted by three or more burner blocks. May be. In this case, for each combination of burner blocks to be burned, correlation data between the target combustion amount (Qa) and the drain prevention temperature (Td) is prepared and stored in advance in the memory, and the burner blocks to be burned are combined. The drain prevention temperature may be determined based on the correlation data selected accordingly.
[0077]
Further, the reheating burner 51 and the heating burner 111 may be constituted by a plurality of burner blocks, similarly to the hot water supply burner 11.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a hot water supply device with a reheating function according to a first embodiment of the present invention.
FIG. 2 is an operation flowchart of the hot water supply apparatus shown in FIG.
FIG. 3 is an operation flowchart of the hot water supply apparatus shown in FIG. 1;
4 is a graph showing the relationship between the burner combustion amount and the heat efficiency of the heat exchanger in the hot water supply apparatus shown in FIG. 1 and a correlation map for determining the drain prevention temperature from the burner combustion amount.
FIG. 5 is an overall configuration diagram of a heating heat source device according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hot water supply apparatus with a reheating function, 4 ... Hot water supply part, 7 ... Reheating part, 10 ... Hot water supply heat exchanger, 11 ... Hot water supply burner, 15 ... Hot water supply combustion fan, 16 ... Hot water supply heat exchanger temperature sensor, 30 ... Bypass pipe 31 ... Bypass servo valves 31, 50 ... Reheating heat exchanger, 51 ... Reheating burner, 54 ... Reheating combustion fan, 55 ... Reheating heat exchange temperature sensor, 56 ... Reheating circulation pump, 100 ... Heating heat source device DESCRIPTION OF SYMBOLS 103 ... Floor heating terminal, 110 ... Heating heat exchanger, 111 ... Heating burner, 115 ... Heating combustion fan, 116 ... Heating heat exchange temperature sensor, 120 ... Bypass pipe, 121 ... Bypass servo, 123 ... Heating circulation pump, 140 …controller

Claims

A heat exchanger for heating and supplying the supplied water, a burner for heating the heat exchanger, a combustion amount adjusting means for adjusting a combustion amount of the burner, and a target combustion amount of the burner according to a predetermined condition Target combustion amount determining means for determining the combustion amount, combustion amount control means for controlling the combustion amount of the burner to the target combustion amount by the combustion amount adjusting means, and heat for detecting the temperature of hot water discharged from the heat exchanger An AC temperature sensor, thermal AC amount adjusting means for adjusting the flow rate of water supplied to the heat exchanger, and the heat exchanger supplied to the heat exchanger so that the detected temperature of the heat exchanger temperature sensor becomes a predetermined drain prevention temperature. In a flow type water heating apparatus provided with thermal AC amount control means for adjusting the flow rate of water to be adjusted by the thermal AC amount adjustment means,
The heat exchanger heats water supplied from a water supply pipe and discharges it to a hot water supply pipe,
A bypass pipe that bypasses the heat exchanger and communicates the water supply pipe and the hot water supply pipe; a flow rate of water that flows through the heat exchanger as the thermal AC amount adjusting means; and a flow rate of water that flows through the bypass pipe A bypass ratio adjusting means for adjusting a bypass ratio that is a ratio of the hot water supply, a hot water supply temperature sensor that detects a temperature of hot water supplied to a downstream side of a joining point of the hot water supply pipe and the bypass pipe,
Storage means for storing in advance correlation data between the combustion amount of the burner and the lower limit temperature at which no drainage occurs in the heat exchanger;
A drain prevention temperature setting means for setting the drain prevention temperature near the lower limit temperature corresponding to the target combustion amount based on the correlation data ;
The target combustion amount determination means determines the target combustion amount as the predetermined condition so that a detected temperature of the hot water supply temperature sensor coincides with a predetermined target hot water supply temperature,
The flow rate water heating device, wherein the heat AC amount control means adjusts a flow rate of water supplied to the heat exchanger by changing the bypass ratio by the bypass ratio adjusting means .

A heat exchanger for heating and supplying the supplied water, a burner for heating the heat exchanger, a combustion amount adjusting means for adjusting a combustion amount of the burner, and a target combustion amount of the burner according to a predetermined condition Target combustion amount determining means for determining the combustion amount, combustion amount control means for controlling the combustion amount of the burner to the target combustion amount by the combustion amount adjusting means, and heat for detecting the temperature of hot water discharged from the heat exchanger An AC temperature sensor, thermal AC amount adjusting means for adjusting the flow rate of water supplied to the heat exchanger, and the heat exchanger supplied to the heat exchanger so that the detected temperature of the heat exchanger temperature sensor becomes a predetermined drain prevention temperature. In a flow type water heating apparatus provided with thermal AC amount control means for adjusting the flow rate of water to be adjusted by the thermal AC amount adjustment means,
The heat exchanger communicates with the bathtub through a circulation circuit;
A pump that circulates water in the bathtub through the circulation circuit and the heat exchanger, a bath temperature sensor that detects the temperature of hot water in the bathtub, and a heat exchange amount adjusting means that supplies water to the pump A circulation flow rate adjusting means for adjusting the flow rate of water circulating in the circulation circuit by changing the flow rate;
Storage means for storing in advance correlation data between the combustion amount of the burner and the lower limit temperature at which no drainage occurs in the heat exchanger;
A drain prevention temperature setting means for setting the drain prevention temperature near the lower limit temperature corresponding to the target combustion amount based on the correlation data ;
The target combustion amount determining means determines the target combustion amount according to a difference between a predetermined target reheating temperature and a temperature detected by the bath temperature sensor as the predetermined condition,
The heat AC amount control means adjusts the flow rate of water supplied to the heat exchanger by changing the flow rate of water circulating in the circulation circuit by the circulation flow rate adjustment means. Water heater.

A heat exchanger for heating and supplying the supplied water, a burner for heating the heat exchanger, a combustion amount adjusting means for adjusting a combustion amount of the burner, and a target combustion amount of the burner according to a predetermined condition Target combustion amount determining means for determining the combustion amount, combustion amount control means for controlling the combustion amount of the burner to the target combustion amount by the combustion amount adjusting means, and heat for detecting the temperature of hot water discharged from the heat exchanger An AC temperature sensor, thermal AC amount adjusting means for adjusting the flow rate of water supplied to the heat exchanger, and the heat exchanger supplied to the heat exchanger so that the detected temperature of the heat exchanger temperature sensor becomes a predetermined drain prevention temperature. In a flow type water heating apparatus provided with thermal AC amount control means for adjusting the flow rate of water to be adjusted by the thermal AC amount adjustment means,
The heat exchanger communicates with the heating terminal via a circulation circuit;
A pump for supplying water heated by the heat exchanger to the heating terminal via the circulation circuit, and recovering water radiated by the heating terminal to the heat exchanger;
A bypass pipe that bypasses the heat exchanger and communicates the upstream side and the downstream side of the circulation circuit; and a flow rate of water that flows through the heat exchanger and water that flows through the bypass pipe as the thermal AC amount adjusting means. A bypass ratio adjusting means for adjusting a bypass ratio that is a ratio to a flow rate, a hot water supply temperature sensor that detects a temperature of hot water supplied to a downstream side of a joining point of the circulation circuit and the bypass pipe,
Storage means for storing in advance correlation data between the combustion amount of the burner and the lower limit temperature at which no drainage occurs in the heat exchanger;
A drain prevention temperature setting means for setting the drain prevention temperature near the lower limit temperature corresponding to the target combustion amount based on the correlation data ;
The target combustion amount determination means determines the target combustion amount as the predetermined condition so that a detected temperature of the hot water supply temperature sensor coincides with a predetermined target hot water supply temperature,
The flow rate water heating device, wherein the heat AC amount control means adjusts a flow rate of water supplied to the heat exchanger by changing the bypass ratio by the bypass ratio adjusting means .

The burner is composed of a plurality of burner blocks,
The storage means stores, for each combination of burner blocks to be burned, correlation data between a burn amount of the burner and a lower limit temperature at which no drainage occurs in the heat exchanger,
The drain prevention temperature setting means selects the correlation data corresponding to a combination of burner blocks during combustion, and sets the drain prevention temperature based on the selected correlation data. The flow-type water heating apparatus of any one of Claim 3 .

The drain-out prevention temperature setting means, within a predetermined time from the ignition is made of the burner, the drain preventing temperature from claim 1, characterized in that the set or predetermined temperature higher than the lower limit temperature of claims 4 The flow-type water heating apparatus of any one of them.