JP3727388B2

JP3727388B2 - Combined water heater

Info

Publication number: JP3727388B2
Application number: JP27649095A
Authority: JP
Inventors: 寿久斉藤; 久恭渡辺; 喜久雄岡本
Original assignee: 株式会社ガスター
Priority date: 1995-09-29
Filing date: 1995-09-29
Publication date: 2005-12-14
Anticipated expiration: 2015-09-29
Also published as: JPH0996444A

Description

【０００１】
【発明の属する技術分野】
本発明は、給湯バーナと風呂バーナとを備えた複合給湯装置に関するものである。
【０００２】
【従来の技術】
図４には従来の一般的な複合給湯装置のシステム構成が示されている。同図において、器具１内は仕切り部２を介して、給湯燃焼室３と風呂燃焼室４とに区画されており、給湯燃焼室３には給湯バーナ５が設けられ、風呂燃焼室４には風呂バーナ６が設けられている。各バーナ５，６にはそれぞれ、バーナ５，６の点着火用のイグナイタ電極27ａ，27ｂと炎検出用のフレームロッド電極28ａ，28ｂが設けられている。なお、同図に示す給湯バーナ５は、その燃焼面をＡ面、Ｂ面、Ｃ面に分けた多段燃焼式のバーナである。
【０００３】
前記給湯バーナ５と風呂バーナ６は仕切り部２を介して並設されており、各バーナ５，６のガス導入口側には、ガスノズル（図示せず）が対向配置されている。ガスノズルに通じるガス供給通路36には、元電磁弁37とガス比例弁38が設けられており、ガス比例弁38の下流側のガス供給通路36を分岐させて給湯能力制御弁39（39ａ，39ｂ，39ｃ）と、風呂能力制御弁40にガスが導かれている。給湯バーナ５と風呂バーナ６の下方側は共通の空気チャンバ（空気室）７となっており、この空気チャンバ７の底面側には給排気用の燃焼ファン８が連設されている。
【０００４】
前記給湯燃焼室３には、給湯バーナ５の上方側に給湯熱交換器15が設置されており、この給湯熱交換器15は、水道等の水供給源から給水通路19を介して導入される水を、給湯バーナ５の燃焼火炎によって加熱して設定温度の湯を作り出し、この湯を、給湯熱交換器15の出側に接続される給湯通路20を介して台所や浴室等の所望の給湯場所に導き出湯を行う。なお、給水通路19には流量センサ41が介設されており、水供給源から給湯器に供給される水の流量が検出されるようになっている。また、図中、30は入水温度センサ、31は出湯温度センサを示しており、これらのセンサによって給湯熱交換器15への入水温度と給湯熱交換器15からの出湯温度とがそれぞれ検出される。
【０００５】
前記風呂燃焼室４には前記風呂バーナ６の上方側に追い焚き熱交換器16が設置されており、この追い焚き熱交換器16の入口側には管路22の一端側が接続され、管路22の他端側は循環ポンプ23の吐出側に接続されている。この管路22には通水の温度を検出するサーミスタ等の風呂温度センサ24が設けられている。
【０００６】
循環ポンプ23の吸込側には追い焚き循環路25の戻り管26が接続されており、循環口である戻り管26の戻り口側は浴槽（図示せず）の側壁に接続されている。この戻り管26には通水を検知してオン信号を出力する追い焚き流水スイッチ（図示せず）が設けられている。追い焚き熱交換器16の出口側には追い焚き循環路25の往管29の入口側が接続されており、往管29の出口側は浴槽の側壁に接続されている。追い焚き熱交換器16は、浴槽からの循環湯水を導入して風呂バーナ６の燃焼火炎によって加熱し、この加熱した湯を浴槽に戻すことで、風呂の追い焚きを行うようになっている。
【０００７】
前記給湯通路20には湯張り用管32が分岐されて管路22と接続されており、この湯張り用管32には、注湯制御弁としての注湯弁35と、浴槽水位を検出する水位検出センサとしての圧力センサ34とが設けられている。また、前記給湯燃焼室３および風呂燃焼室４は、それぞれ、排気口42ａ，42ｂに連通して排気口42ａ，42ｂは共通の排気通路33に導かれており、給湯バーナ５の排気ガスと風呂バーナ６の排気ガスとが共通の排気通路33を通って排出されるようになっている。
【０００８】
この種の複合給湯装置には、給湯バーナ燃焼および風呂バーナ燃焼等の制御を行う制御装置18が設けられており、制御装置18には、リモコン17が接続されている。この制御装置18には、前記流量センサ41等の様々なセンサからの信号が加えられるようになっており、例えば、給湯通路20が導かれている台所等の給湯場所に設けられた給湯栓（図示せず）が開かれ、水道等の水供給源から給水通路19に水が導入されると、制御装置18は流量センサ41から入水信号を受けたときに燃焼ファン８を回転する。
【０００９】
そして、ガス供給通路36の元電磁弁８とガス比例弁38と給湯能力制御弁39を開き、図７の（ａ）の特性線ｂに示す如く、給湯バーナ５に安定して火がつく程度のガス量の供給、いわゆる緩点火のガス量供給を行い、その状態でイグナイタ電極27ｂによって給湯バーナ５の点着火を行う。その後、フレームロッド電極28ｂで炎を検知し、制御装置18は、出湯温度センサ31で検出される出湯温度がリモコン17で設定される設定温度となるようにＰＩＤ演算等によるガス供給量の比例制御を行い、かつ、燃焼ファン８の回転制御を行って給湯モードでの給湯運転を制御する。
【００１０】
この制御によって給湯の出湯温は徐々に高められて給湯設定温度に達するが、出湯温はガスの着火後直ちに上昇することなく、同図の特性線ｃに示すように、給湯栓を開栓してから点火するまでに時間がかかり、さらに、ガスが点着火した後、ガス燃焼による熱が給湯熱交換器15から給湯熱交換器15内を通る水に伝熱するまでに時間がかかり、結局、給湯栓を開いてから給湯側の入水の湯温が立ち上がるまでの湯温立ち上がり時間Ｂを過ぎてから出湯温は徐々に上昇し、給湯設定温度に達して安定する。なお、同図の特性線ｃに示した出湯温の変化は給湯器をコールドスタートさせた場合、すなわち、給湯器を設置して初めて給湯栓を開栓したり、又は、給湯燃焼停止後、例えば、器具が冷えきるだけの長い時間を経てから再出湯を行った場合のものを示している。
【００１１】
また、この種の給湯装置において、前記制御装置18は、電磁弁等の注湯弁35を開けることにより、給湯熱交換器15側で作り出した湯を追い焚き循環路25を介して浴槽内に落とし込んで湯張りを行う湯張りモードの運転動作機能を備えている。この自動湯張り動作はリモコン17等の指令により行われ、圧力センサ34により湯張りの水位がリモコン17等で設定される設定水位に達したときに注湯弁35が閉じられて湯張りの停止が行われ、次に循環ポンプ23を起動して追い焚きモードでの運転が行われるものである。
【００１２】
この追い焚き運転に際して、制御装置18は、まず、追い焚き循環路25の循環ポンプ23を回転させて、浴槽内の湯水を追い焚き循環路25を介して循環させる。そして、前記追い焚き流水スイッチが湯水の流れを検知したときに、制御装置18は燃焼ファン８を回転し、電磁弁を開き、イグナイタ電極27ａによる点着火により風呂バーナ６を燃焼させて追い焚き熱交換器16を通る循環湯水を加熱して浴槽内の湯水の追い焚きを行う。
【００１３】
【発明が解決しようとする課題】
ところで、この種の給湯装置において、給湯燃焼運転停止以降に、給湯熱交換器15に保有されている熱量が給湯熱交換器15に残留している湯に伝わって湯温が上昇する現象が生じ、この現象により、給湯熱交換器15内の残留湯温が給湯設定温度よりも高くなり、その後、自然冷却によって低下していく。一方、再出湯時には、給湯熱交換器15内への入水が行われ、この水が給湯バーナ５で加熱されることにより、湯温（水温）が、前記の如く、図７の（ａ）の特性線ｃに示したようにして上昇していく。
【００１４】
そのため、同図に示されるように、この特性線ｃに示される給湯開始からの湯温立ち上がり時間Ｂと、再出湯の給湯開始時から給湯熱交換器15の残留湯温が設定湯温に低下するまでの後沸き時間Ａ（この後沸き時間Ａは、給湯燃焼停止前の燃焼熱量と、給湯燃焼停止時から再出湯開始までの待機時間等に応じた値となる）とが一致する場合には、給湯熱交換器15内の湯温の降下分と、給湯バーナ５の燃焼による湯温の上昇分とがキャンセルされて、再出湯湯温特性は同図の特性線ｓに示すようになり、再出湯時において、初めは給湯設定温度より少し高めの湯が出るが、その後、すぐに給湯設定温度の湯が出湯される。
【００１５】
ところが、例えば図７の（ｂ）に示すように、前記後沸き時間Ａが例えば300 秒といった長い時間の場合には、この後沸き時間Ａが前記立ち上がり時間Ｂよりも長いことから、給湯熱交換器15内の残留湯温が給湯設定温度以下に下がっていない状態で、制御装置18のＰＩＤ演算やＦＦ（フィードフォワード）のみの制御等によるガス供給量の比例制御によって給湯バーナ５の燃焼が行われるために、再出湯湯温特性は同図の特性線ｓに示すようになり、出湯湯温が給湯設定温度よりもかなり高めの温度となり、湯の使用者に大きな不快感を与えていた。
【００１６】
そこで、本出願人は、給湯燃焼停止以降の再出湯時に給湯設定温度よりもかなり高めのオーバーシュートの湯が出ることを防ぐために、例えば図６の（ａ）の特性線ｂに示すように、再出湯時の緩点火後の給湯バーナ５への供給ガスレベルを、緩点火時の給湯バーナ５への供給ガスレベルよりも低い最小ガスレベルに設定してガス供給を行った後に、前記比例制御によるガス供給を行うことを考えた。このようにすると、同図の特性線ｃに示すように、給湯開始からの入水湯温の湯温立ち上がり時間Ｂが長くなり、この湯温立ち上がり時間Ｂ_Rと後沸き時間Ａとが一致するために、図７の（ａ）に示した後沸き時間Ａが短い場合と同様に、給湯設定温度よりもかなり高めのオーバーシュートの湯の出湯を防止することができる。
【００１７】
なお、この緩点火後の最小ガスレベルでのガス供給時間は、例えば給湯燃焼停止前の燃焼熱量および給湯燃焼停止時から再出湯開始までの待機時間から計算等によって後沸き時間Ａを求め、この後沸き時間Ａからコールドスタート時の湯温立ち上がり時間Ｂ（予め実験等により求めておく）を引いた時間（Ａ−Ｂ）に設定される。
【００１８】
しかしながら、図４に示したような、共通の燃焼ファン８によって給湯バーナ燃焼と風呂バーナ燃焼の給排気を行うタイプの複合給湯装置においては、風呂バーナ６の燃焼中に給湯バーナ５側の給湯燃焼室３内を燃焼ファン８によって強制排気掃風するために、給湯燃焼停止以降の再出湯が行われるまでの間に風呂バーナ燃焼が行われると、この風呂バーナ燃焼に伴う燃焼ファン８の掃風により、給湯熱交換器15が冷やされ、給湯熱交換器15内の残留湯温特性が図６の（ｂ）の特性線ａに示すようになり、前記の如く計算等により求めた後沸き時間Ａ（風呂バーナ燃焼が行われないときの後沸き時間）よりも実際の後沸き時間Ａ_Rが短くなる。そうすると、湯温立ち上がり時間Ｂ_Rよりも後沸き時間Ａ_Rの方が短くなる。
【００１９】
こうなると、給湯バーナ５の燃焼による湯温の上昇分が給湯熱交換器15内の湯温の降下分に追いつかず、再出湯時に、初めは設定温度より少し高めの湯が出た後、給湯設定温度よりもかなり低めのアンダーシュートの湯が出て湯温の変動があり、湯の使用者に不快感を与えてしまうといった問題が生じた。
【００２０】
本発明は上記課題を解決するためになされたものであり、その目的は、給湯燃焼停止以降の再出湯時に湯温のオーバーシュートやアンダーシュートを抑制し、気持ち良く湯の使用を行える複合給湯装置を提供することにある。
【００２１】
【課題を解決するための手段】
上記目的を達成するために、本発明は次のような構成により課題を解決するための手段としている。すなわち、本発明は、給湯熱交換器の加熱燃焼を行う給湯バーナと、追い焚き熱交換器の加熱燃焼を行う風呂バーナと、前記給湯バーナ燃焼と風呂バーナ燃焼の給排気を行う共通の又は個別の燃焼ファンとを備え、前記風呂バーナの燃焼中には前記給湯バーナ側の燃焼室内を燃焼ファンによって強制排気掃風するタイプの複合給湯装置において、前記風呂バーナ燃焼に伴う前記給湯熱交換器の強制排気掃風による放熱量を推定検出する給湯側蓄熱損失量検出部と、給湯燃焼停止以降の再出湯時の緩点火後の設定時間だけ給湯バーナへのガス供給レベルを前記給湯側蓄熱損失量検出部によって検出される検出放熱量が大きくなるにつれて大きい値に設定し検出放熱量が小さくなるにつれて小さい値に設定して制御するガス供給レベル制御手段とが設けられていることを特徴として構成されている。
【００２２】
また、前記給湯側蓄熱損失量検出部は給湯燃焼停止から再出湯開始までに行われる風呂バーナの燃焼時間に対応する量を給湯熱交換器の検出放熱量として検出する構成としたこと、前記ガス供給レベル制御手段によるガスレベル制御時間を再出湯の給湯開始時から給湯熱交換器の残留湯温が設定湯温に低下するまでの後沸き時間と、給湯開始から給湯側の入水の湯温が立ち上がるまでの湯温立ち上がり時間との差に基づいて設定する緩点火後レベル制御時間設定手段が設けられていることも本発明の特徴的な構成とされている。
【００２３】
上記構成の本発明においては、給湯側蓄熱損失量検出部によって、風呂バーナ燃焼に伴う給湯熱交換器の強制排気掃風による放熱量が推定検出され、この検出放熱量に基づき、ガス供給レベル制御手段によるガス供給レベル制御が行われる。この制御は、給湯燃焼停止以降の再出湯時の緩点火後の設定時間行われるものであり、前記給湯側蓄熱損失量検出部によって検出される検出放熱量が大きくなるにつれて給湯バーナへのガス供給レベルが大きい値に設定され、検出放熱量が小さくなるにつれて給湯バーナへのガス供給レベルが小さい値に設定されて制御される。
【００２４】
すなわち、本発明においては、給湯燃焼停止以降の再出湯が行われるまでに風呂バーナ燃焼が行われ、この風呂バーナ燃焼に伴う強制排気掃風により給湯熱交換器の放熱が行われても、その放熱量が大きくなるにつれて給湯熱交換器内の残留湯温の降下のタイミングが早くなる分だけ、再出湯時の緩点火後の設定時間供給する給湯バーナへのガス供給レベルが大きく設定制御されて、入水湯温の上昇のタイミングが早くなり、残留湯温の降下分が給湯バーナ燃焼による湯温上昇分で補われることにより、再出湯湯温の安定化制御が行われ、上記課題が解決される。
【００２５】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて説明する。なお、本実施形態例の説明において、従来例と同一名称部分には同一符号を付し、その重複説明は省略する。本実施形態例の複合給湯装置は、図４に示した従来の複合給湯装置とほぼ同様に構成されており、本実施形態例が従来例と異なる特徴的なことは、給湯燃焼停止以降の再出湯時に給湯湯温の安定化制御を行うための特有な回路を設けたことである。
【００２６】
この特有の回路は、図１に示すように、給湯燃焼制御部43、経過時間計測手段44、後沸き時間算出部45、メモリ部47、ガス供給レベル制御手段46、緩点火後レベル制御時間設定手段49、風呂燃焼制御部48、風呂燃焼時間計測部50、給湯側蓄熱損失量検出部51を有して構成されている。
【００２７】
給湯燃焼制御部43は、出湯温度センサ32、入水温度センサ31、流量センサ41、リモコン17等からの信号を取り込み、前記の如く、給湯モードでの給湯運転制御および湯張りモードの運転制御等を行うものであり、風呂燃焼制御部48は、浴槽内の湯水の追い焚き運転制御等を行うものであり、これらの制御動作は従来例と同様であるので、その重複説明は省略する。
【００２８】
経過時間計測手段44は、給湯燃焼制御部43からの給湯燃焼停止信号と流量センサ41からの入水信号を取り込み、給湯燃焼停止時から再出湯時までの経過時間を計測し、再出湯までの待機時間として後沸き時間算出部45に加える。
【００２９】
後沸き時間算出部45は、待機時間中に風呂バーナ燃焼が行われないときの、再出湯の給湯開始時から給湯熱交換器15の残留湯温が設定湯温に低下するまでの後沸き時間Ａを求めるものである。この後沸き時間Ａの算出に際し、メモリ部47には、給湯燃焼停止前の給湯の設定温度、入水温度、入水量等によって求まる燃焼熱量（燃焼能力）、器具内温度、給湯燃焼停止時から再出湯時までの経過時間（待機時間）等のファクターを様々に変えたときの、対応する後沸き時間データが与えられている。後沸き時間算出部45は、このデータと、給湯燃焼制御部43から加えられる給湯燃焼停止前の燃焼熱量の値、経過時間計測手段44から加えられる待機時間の値、器具内温度検出センサ（図示せず）から取り込まれる器具内温度に基づいて、待機時間中に風呂バーナ燃焼が行われないときの後沸き時間Ａを算出し、緩点火後レベル制御時間設定手段49に加える。
【００３０】
緩点火後レベル制御時間設定手段49は、後沸き時間算出部45から加えられる後沸き時間Ａ（計算値）と、メモリ部47に予め与えられている、コールドスタート時の給湯開始から給湯側の入水の湯温が立ち上がるまでの湯温立ち上がり時間Ｂとの差に基づいて、給湯燃焼停止以降の再出湯時の緩点火後に行われるガス供給レベル制御手段46によるガスレベル制御時間（設定時間）を設定するものである。緩点火後レベル制御時間設定手段49には、ガス供給レベル制御手段46によるガスレベル制御時間Ｔ_Cを求める演算式として、（Ｔ_C＝Ａ−Ｂ）が与えられており、緩点火後レベル制御時間設定手段49は、この演算式により、後沸き時間Ａから湯温立ち上がり時間Ｂを差し引いた値を求め、この値をガスレベル制御時間としてガス供給レベル制御手段46に加える。なお、前記（Ａ−Ｂ）の値が０以下になったときには、緩点火後ガスレベル制御時間の設定は行わない。
【００３１】
風呂燃焼時間計測部50は、給湯燃焼制御部43からの給湯燃焼停止信号と流量センサ41の入水信号および、風呂燃焼制御部48からの燃焼開始信号と燃焼停止信号とを受けて、給湯燃焼停止から再出湯開始までに行われる風呂バーナ６の燃焼時間を計測するものであり、この計測時間を給湯側蓄熱損失量検出部51に加える。
【００３２】
給湯側蓄熱損失量検出部51は、風呂バーナ６の燃焼に伴う給湯熱交換器15の強制排気掃風による放熱量を推定検出するものであり、本実施形態例では、給湯側蓄熱損失量検出部51は、風呂燃焼時間計測部50からの風呂燃焼計測時間の値を受けて、給湯燃焼停止から再出湯開始までに行われる風呂バーナ６の燃焼時間に対応する量を給湯熱交換器15の検出放熱量として検出する構成としている。給湯側蓄熱損失量検出部51は、検出した検出放熱量の値をガス供給レベル制御手段46に加える。
【００３３】
ガス供給レベル制御手段46は、前記緩点火後レベル制御時間設定手段49から加えられるガスレベル制御時間の値を受けて、給湯燃焼停止以降の再出湯時の緩点火後に、この設定されたガスレベル制御時間Ｔ_Cだけ給湯バーナ５へのガス供給レベルを設定制御するものである。この設定制御に際し、ガス供給レベル制御手段46は、前記給湯側蓄熱損失量検出部51によって検出される検出放熱量が大きくなるにつれてガス供給レベルを大きい値に設定して制御し、検出放熱量が小さくなるにつれてガス供給レベルを小さい値に設定して制御する。
【００３４】
このガス供給レベル制御手段46によるガス供給レベルの制御を的確に行うために、本実施形態例では、図３の（ａ）に示すように、待機時間中の風呂バーナ６の燃焼時間に対応して、この燃焼時間が長くなるにつれて（給湯側蓄熱損失量検出部51による検出放熱量が大きくなるにつれて）給湯バーナ５へのガス供給レベルを段階的に高く設定するグラフデータが、ガス供給レベル制御手段46に与えられている。
【００３５】
ガス供給レベル制御手段46は、このグラフデータに基づいて、前記待機時間中の風呂バーナ燃焼時間に応じたガス供給レベル制御を行う。すなわち、風呂バーナ燃焼時間が長く、それにより燃焼ファン８の強制排気掃風による給湯熱交換器15の放熱量が大きくなるにつれて（大きいときほど）、再出湯時の緩点火後の設定時間に給湯バーナ５へ供給するガス供給レベルを段階的に大きい値に設定し、待機時間中の風呂バーナ燃焼時間が短く、前記放熱量が小さくなるにつれて（小さいときほど）、前記緩点火後の設定時間に給湯バーナ５へ供給するガス供給レベルを段階的に小さい値に設定してガス比例弁38の開弁量を制御するようになっている。
【００３６】
本実施形態例は以上のように構成されており、本実施形態例でも従来例と同様に、制御装置18によって、給湯モードや湯張りモード、追い焚きモード等による制御動作が行われる。なお、給湯モードおよび湯張りモード等の制御動作は給湯燃焼制御部43によって行われ、追い焚きモードの動作は風呂燃焼制御部48によって行われる。
【００３７】
また、本実施形態例では、給湯燃焼停止以降の再出湯時の湯温安定化制御が以下のようにして行われる。給湯燃焼が停止されると、給湯燃焼停止信号が経過時間計測手段44と後沸き時間算出部45、風呂燃焼時間計測部50にそれぞれ加えられる。そうすると、経過時間計測手段44は、給湯燃焼停止信号が加えられてから流量センサ41からの入水信号が加えられるまで、すなわち、給湯燃焼停止時から再出湯時までの待機時間を計測し、後沸き時間算出部45に加える。
【００３８】
一方、後沸き時間算出部45は、前記給湯燃焼停止信号を受けたときに、この給湯燃焼停止信号と共に給湯燃焼停止前の燃焼熱量を求め、また、前記器具内温度検出センサ（図示せず）からの器具内温度検出信号を取り込み、さらに、経過時間計測手段44から加えられる待機時間の値を受けて、待機時間中に風呂バーナ燃焼が行われないときの給湯熱交換器15の残留湯温の後沸き時間Ａを算出し、緩点火後レベル制御時間設定手段49に加える。
【００３９】
そうすると、緩点火後レベル制御時間設定手段49は、この後沸き時間Ａと、メモリ部47に予め与えられているコールドスタート時の湯温立ち上がり時間Ｂとの差（Ａ−Ｂ）を求めてこの値を緩点火後のガス供給レベル制御時間Ｔ_Cとして設定し、ガス供給レベル制御手段46に加える。
【００４０】
一方、前記給湯燃焼制御部43からの給湯燃焼停止信号が風呂燃焼時間計測部50に加えられてから、風呂燃焼時間計測部50による待機時間中の風呂バーナ６の燃焼時間の計測が行われ、この計測値が給湯側蓄熱損失量検出部51に加えられ、この値が給湯熱交換器15の検出放熱量として給湯側蓄熱損失量検出部51からガス供給レベル制御手段46に加えられる。なお、前記待機時間中の風呂バーナ６の燃焼時間は、風呂燃焼時間計測部50によって、風呂燃焼制御部48からの風呂燃焼開始信号と風呂燃焼停止信号を取り込むことによって行われる。
【００４１】
ガス供給レベル制御手段46は、給湯側蓄熱損失量検出部51から加えられる給湯熱交換器15の検出放熱量の値、すなわち、本実施形態例では待機時間中の風呂バーナ６の燃焼時間と、ガス供給レベル制御手段46に与えられている例えば図３の（ａ）に示したようなグラフデータとの比較を行う。そして、前記待機時間中に風呂バーナ６の燃焼が全く行われなかったときには、図６の（ｂ）に示したように、本出願人の以前に提案の装置における再出湯時の湯温安定化制御と同様に、再出湯時の緩点火後の設定時間（ガス供給レベル制御時間Ｔ_C）だけ、給湯バーナ５へのガス供給レベルが最小レベルとなるようにガス比例弁38の開弁量の制御が行われ、この設定時間経過以降に給湯バーナ５への供給ガスの比例制御が行われる。この制御により、再出湯後の給湯熱交換器15の後沸き時間Ａと入水の湯温立ち上がり時間Ｂ_Rとが一致させられ、再出湯時には、後沸き時間Ａ中に給湯設定温度よりもやや高めの出湯が行われた後、給湯設定温度の湯の出湯が行われる。
【００４２】
また、給湯燃焼停止以降の待機時間中に風呂バーナ６の燃焼が行われたときには、風呂バーナ６の燃焼時間に応じたガス供給レベル制御が行われる。例えば、待機時間中の風呂バーナ燃焼時間が短く、図２の（ａ）の特性線ａに示すように、風呂バーナ燃焼に伴う前記強制排気掃風による給湯熱交換器15の残留湯温の降下の割合が小さく、後沸き時間が短くなる割合（Ａ−Ａ_R）が小さいときには、ガス供給レベル制御手段49により、図３の（ａ）の制御データに基づき、再出湯時の緩点火後の設定時間に給湯バーナ５へ供給されるガス供給レベルは小さく設定され、ガス供給レベルは図２の（ａ）の特性線ｂに示すように制御される。
【００４３】
そして、同図の特性線ｃに示すように、給湯熱交換器15への入水の湯温の上昇が特性線ｃに示すように、ガス供給レベル制御時間Ｔ_C中のガスレベルを最小レベルとした場合の湯温立ち上がり時間Ｂ_R′よりも早い時間Ｂ_Rから徐々に行われた後に、給湯バーナ５へのガス供給レベルの比例制御による給湯熱交換器15への入水湯温の上昇が特性線ｃのＢ_Sから行われることにより、出湯湯温がアンダーシュートを起こすことはなく、また、大幅なオーバーシュートも起こすことなく、同図の特性線ｓに示す如く、安定した湯温の出湯が行われる。
【００４４】
一方、待機時間中の風呂バーナ６の燃焼時間が長く、例えば図２の（ｂ）の特性線ａに示すように、風呂バーナ燃焼に伴う前記強制排気掃風によって給湯熱交換器15内の残留湯温の降下の割合が大きいときには、ガス供給レベル制御手段により、同図の特性線ｂに示す如く、再出湯時の緩点火後の設定時間に給湯バーナ５へ供給される供給ガスレベルが大きい値に設定されてガス比例弁38の開弁量の制御が行われる。そうすると、同図の特性線ｃに示すように、給湯熱交換器15への入水の湯温が、ガス供給レベル制御時間Ｔ_C中のガスレベルを最小レベルとした場合の湯温立ち上がり時間Ｂ_R′よりも早い時間Ｂ_Rから急激に上昇するために、前記強制排気掃風による給湯熱交換器15内の残留湯温の降下分が入水湯温の上昇分によって補われ、同図の特性線ｓに示す如く、出湯湯温は給湯設定温度とほぼ等しい温度となって出湯される。
【００４５】
本実施形態例によれば、上記動作により、給湯燃焼停止以降の再出湯時の緩点火後に、給湯バーナ５へのガス供給レベルを調整する緩点火後ガスレベル制御時間を設定し、この設定時間だけ、給湯バーナ５へのガス供給レベルを給湯熱交換器15の強制排気掃風による放熱量が大きくなるにつれて大きい値に設定し、放熱量が小さくなるにつれて小さい値に設定して制御するために、給湯燃焼停止時から再出湯時までの間の待機時間中に風呂バーナ６の燃焼が行われ、この風呂バーナ燃焼に伴う強制排気掃風が行われて給湯熱交換器15の放熱が行われても、この放熱の影響を緩点火後の給湯バーナ５の燃焼の割合によって補うことが可能となり、給湯設定温度にほぼ等しい湯温の出湯を行うことができる。
【００４６】
なお、本発明は上記実施形態例に限定されることはなく、様々な実施の態様を採り得る。例えば、上記実施形態例では、ガス供給レベル制御手段46に、図３の（ａ）に示したような、風呂バーナ燃焼時間が多くなるにつれて、給湯バーナ５へのガス供給レベルを段階的に大きく設定するグラフデータを与えたが、同図の（ｂ）に示すように、風呂バーナ燃焼時間が多くなるにつれてガスレベルを連続的に大きく設定するグラフデータを与えてもよい。また、これらのグラフデータの代わりに、テーブルデータや演算式等を与えてもよい。
【００４７】
また、上記実施形態例では、ガス供給レベル制御手段46に直接、再出湯時の緩点火後の設定時間に給湯バーナ５へ供給するガスレベルの制御データを与えたが、この制御データは、例えばメモリ部47に格納し、この格納データをガス供給レベル制御手段46によって取り込んでガス供給レベル制御を行うようにしてもよい。
【００４８】
さらに、上記実施形態例では、後沸き時間演算部45は、メモリ部47に格納した給湯燃焼停止前の前回燃焼熱量と器具内温度、待機時間等のファクターを変えたときの後沸き時間のデータに基づいて後沸き時間を算出するようにしたが、これらのデータの代わりに、各ファクターに基づいて後沸き時間を算出する演算式をメモリ部47等に与え、この演算式に基づいて後沸き時間を算出するようにしてもよい。
【００４９】
さらに、上記実施形態例では、給湯側蓄熱損失量検出部51は、待機時間中の風呂バーナ燃焼に伴う強制排気掃風による給湯熱交換器15の放熱量を、待機時間中に行われる風呂バーナ６の燃焼時間に対応する量として検出するようにしたが、例えば、メモリ部47等に、風呂バーナ燃焼時間や器具内温度、待機時間等の様々なファクターを変えたときの給湯熱交換器15の放熱量のデータや、各ファクターによって放熱量を求める演算式を与えておき、待機時間中の風呂バーナ６の燃焼時間に加えて、これらのデータや演算式に基づいて給湯熱交換器15の放熱量を検出するようにしてもよい。
【００５０】
さらに、給湯側蓄熱損失量検出部51は、例えば待機時間中の前半に風呂バーナ６の燃焼が行われたか、あるいは待機時間中の後半に風呂バーナ６の燃焼が行われたか等の待機時間中の風呂バーナ燃焼のタイミングによって、給湯熱交換器15の放熱量を補正するようにしてもよい。
【００５１】
さらに、上記実施形態例では、ガスを給湯バーナ５と風呂バーナ６とに導く共通のガス供給通路36にガス比例弁38を設け、このガス比例弁38の開弁量を調整することにより、給湯バーナ５へのガス供給レベルを制御するようにしたが、例えば図４の38ａ，38ｂに示すように、ガス供給通路36の分岐側にそれぞれガス比例弁を設け、給湯バーナ５側のガス比例弁38ａの開弁量を調整して給湯バーナ５へのガス供給レベルを制御するようにしてもよい。
【００５２】
さらに、上記実施形態例では、給湯燃焼室３の排気口42ａと風呂燃焼室４の排気口42ｂを個別に設け、この排気口42ａ，42ｂを共通の排気通路33に導く構成としたが、本発明の複合給湯装置は、例えば図５の（ｄ）に示すように、給湯燃焼室３と風呂燃焼室４の排気口を供給の排気口42とした複合給湯装置にも適用されるものである。
【００５３】
さらに、上記実施形態例では、給湯バーナ５と風呂バーナ６の他方側に共通の燃焼ファン８を設けて構成したが、本発明の複合給湯装置は、例えば図５の（ａ）から（ｃ）に示すように、給湯バーナ５の給排気用の燃焼ファン８ａと風呂バーナ６の給排気用の燃焼ファン８ｂとを別々に設けた複合給湯装置においても適用されるものであり、風呂バーナ６の燃焼中に給湯バーナ５側の燃焼室３内を燃焼ファンによって強制排気掃風するタイプの複合給湯装置に広く適用されるものである。
【００５４】
さらに、上記実施形態例では、給湯バーナ５の燃焼を行う給湯燃焼室３と風呂バーナ６の燃焼を行う風呂燃焼室４とが１つの器具ケース内に設けられている複合給湯装置としたが、本発明の複合給湯装置は、給湯燃焼室を備えた器具と風呂燃焼室を備えた器具とが別個に設けられ、例えばこれらの各排気口を共通の排気通路に導いて使用するもの等にも適用されるものであり、風呂バーナ６の燃焼中に給湯バーナ５側の燃焼室３内を燃焼ファン８によって強制排気掃風するタイプの複合給湯装置であれば、たとえ給湯燃焼室３と風呂燃焼室４とが離れ離れに配設されていても構わない。
【００５５】
【発明の効果】
本発明によれば、風呂バーナ燃焼時に給湯バーナ側の燃焼室内を燃焼ファンによって強制排気掃風することに伴う給湯熱交換器の放熱量を推定検出し、この検出放熱量に基づいて、給湯燃焼停止以降の再出湯時の緩点火後の設定時間に給湯バーナへ供給するガス供給レベルを設定制御するようにしたものであるから、前記検出放熱量が大きくなるにつれて前記緩点火後の設定時間の給湯バーナへのガス供給レベルを大きい値に設定し、検出放熱量が小さくなるにつれて供給ガスレベルを小さい値に設定することにより、給湯熱交換器の放熱量が大きいほど大きくなる給湯熱交換器内の残留湯温の降下分をガス供給レベルに比例して行われる給湯バーナの燃焼による湯温上昇分によって補うことができる。
【００５６】
そのため、たとえ給湯燃焼停止以降の再出湯までの待機時間中に風呂バーナ燃焼が行われて給湯熱交換器の放熱量が大きくなったとしても、緩点火後の設定時間中のガス供給レベルを大きくすることにより、熱交換器内への入水湯温の上昇が追いつかずにアンダーシュートの湯が出湯されることを抑制することができるし、待機時間中に風呂バーナ燃焼が行われなかったり、行われてもその風呂バーナ燃焼に伴う給湯熱交換器の放熱量が小さいときには、前記緩点火後の設定時間中のガス供給レベルを小さくすることにより、給湯熱交換器内の入水湯温の上昇が大きくなり過ぎて給湯設定温度よりもかなり高めのオーバーシュートの湯の出湯が起こることも抑制することができる。
【００５７】
また、前記給湯側蓄熱損失量検出部は給湯燃焼停止から再出湯開始までに行われる風呂バーナの燃焼時間に対応する量を給湯熱交換器の検出放熱量として検出する構成とした本発明によれば、待機時間中に行われる風呂バーナ燃焼に伴う強制排気掃風による給湯熱交換器の検出放熱量を容易に、かつ、的確に検出することが可能となり、再出湯時の出湯湯温安定化制御を容易に、かつ、的確に行うことができる。
【００５８】
さらに、前記ガス供給レベル制御手段によるガスレベル制御時間を再出湯の給湯開始時から給湯熱交換器の残留湯温が設定湯温に低下するまでの後沸き時間と、給湯開始から給湯側の入水の湯温が立ち上がるまでの湯温立ち上がり時間との差に基づいて設定する緩点火後レベル制御時間設定手段が設けられている本発明によれば、ガス供給レベル制御手段によるガスレベル制御時間の設定を容易に、かつ、的確に行うことができる。
【図面の簡単な説明】
【図１】本発明に係る複合給湯装置に一実施形態例の再出湯湯温安定化制御部を示すブロック構成図である。
【図２】上記実施形態例における待機時間中の風呂バーナ燃焼時間による再出湯安定化制御動作の説明図である。
【図３】本発明に係る複合給湯装置の緩点火後ガス供給レベル制御に用いられる風呂バーナ燃焼時間とガス供給レベルとの関係データを示すグラフである。
【図４】一般的な複合給湯装置の一例を示す構成図である。
【図５】本発明に係る複合給湯装置の他の実施形態例を模式的に示す説明図である。
【図６】本出願人が以前に提案している複合給湯装置による再出湯時の湯温安定化制御動作とその問題点を示す説明図である。
【図７】従来の複合給湯装置における再出湯時の湯温をガス供給レベルと入水湯温と共に示すグラフである。
【符号の説明】
５給湯バーナ
６風呂バーナ
38 ガス比例弁
45 後沸き時間算出部
46 ガス供給レベル制御手段
47 メモリ部
49 緩点火後レベル制御時間設定手段
50 風呂燃焼時間計測部
51 給湯側蓄熱損失量検出部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combined hot water supply apparatus including a hot water supply burner and a bath burner.
[0002]
[Prior art]
FIG. 4 shows a system configuration of a conventional general composite water heater. In the figure, the appliance 1 is divided into a hot water combustion chamber 3 and a bath combustion chamber 4 via a partition 2, and a hot water burner 5 is provided in the hot water combustion chamber 3. A bath burner 6 is provided. The burners 5 and 6 are respectively provided with igniter electrodes 27a and 27b for point ignition of the burners 5 and 6 and flame rod electrodes 28a and 28b for flame detection. The hot water supply burner 5 shown in the figure is a multistage combustion burner whose combustion surface is divided into an A surface, a B surface, and a C surface.
[0003]
The hot-water supply burner 5 and the bath burner 6 are juxtaposed with each other through the partition portion 2, and gas nozzles (not shown) are arranged opposite to the gas inlets of the burners 5 and 6. The gas supply passage 36 communicating with the gas nozzle is provided with an original solenoid valve 37 and a gas proportional valve 38. The gas supply passage 36 on the downstream side of the gas proportional valve 38 is branched to supply a hot water supply capacity control valve 39 (39a, 39b). , 39 c), and the gas is guided to the bath capacity control valve 40. A lower side of the hot water supply burner 5 and the bath burner 6 is a common air chamber (air chamber) 7, and a combustion fan 8 for supplying and exhausting air is connected to the bottom surface side of the air chamber 7.
[0004]
A hot water supply heat exchanger 15 is installed in the hot water supply combustion chamber 3 above the hot water supply burner 5, and the hot water supply heat exchanger 15 is introduced from a water supply source such as a water supply via a water supply passage 19. Water is heated by the combustion flame of the hot water supply burner 5 to produce hot water of a set temperature, and this hot water is supplied to a desired hot water supply such as a kitchen or bathroom via a hot water supply passage 20 connected to the outlet side of the hot water supply heat exchanger 15. Lead to the place and do hot water. A flow rate sensor 41 is interposed in the water supply passage 19 so that the flow rate of water supplied from the water supply source to the water heater is detected. In the figure, reference numeral 30 denotes an incoming water temperature sensor, and 31 denotes a hot water temperature sensor, and these sensors detect the incoming water temperature to the hot water supply heat exchanger 15 and the outgoing hot water temperature from the hot water supply heat exchanger 15, respectively. .
[0005]
In the bath combustion chamber 4, a reheating heat exchanger 16 is installed on the upper side of the bath burner 6, and one end side of a pipe line 22 is connected to the inlet side of the reheating heat exchanger 16. The other end side of 22 is connected to the discharge side of the circulation pump 23. This pipe line 22 is provided with a bath temperature sensor 24 such as a thermistor for detecting the temperature of water flow.
[0006]
A return pipe 26 of the recirculation circuit 25 is connected to the suction side of the circulation pump 23, and the return port side of the return pipe 26, which is a circulation port, is connected to a side wall of a bathtub (not shown). The return pipe 26 is provided with a reheating water switch (not shown) that detects water flow and outputs an ON signal. The outlet side of the reheating heat exchanger 16 is connected to the inlet side of the outgoing pipe 29 of the recirculating circuit 25, and the outlet side of the outgoing pipe 29 is connected to the side wall of the bathtub. The reheating heat exchanger 16 recirculates the bath by introducing circulating hot water from the bathtub and heating it with the combustion flame of the bath burner 6 and returning the heated hot water to the bathtub.
[0007]
A hot water filling pipe 32 is branched into the hot water supply passage 20 and is connected to a pipe 22. The hot water filling pipe 32 detects a hot water filling valve 35 as a hot water pouring control valve and a bathtub water level. A pressure sensor 34 is provided as a water level detection sensor. The hot water combustion chamber 3 and the bath combustion chamber 4 communicate with the exhaust ports 42a and 42b, respectively, and the exhaust ports 42a and 42b are led to a common exhaust passage 33. The exhaust gas from the burner 6 is discharged through a common exhaust passage 33.
[0008]
This type of combined hot water supply apparatus is provided with a control device 18 that performs control such as hot water burner combustion and bath burner combustion, and a remote controller 17 is connected to the control device 18. Signals from various sensors such as the flow rate sensor 41 are applied to the control device 18. For example, a hot water tap provided in a hot water supply place such as a kitchen where the hot water supply passage 20 is guided ( (Not shown) is opened, and when water is introduced into the water supply passage 19 from a water supply source such as a water supply, the control device 18 rotates the combustion fan 8 when receiving a water incoming signal from the flow sensor 41.
[0009]
Then, the original solenoid valve 8, the gas proportional valve 38 and the hot water supply capacity control valve 39 in the gas supply passage 36 are opened, and the hot water supply burner 5 is ignited stably as shown by the characteristic line b in FIG. In this state, the hot water supply burner 5 is ignited by the igniter electrode 27b. Thereafter, the flame is detected by the frame rod electrode 28b, and the control device 18 performs proportional control of the gas supply amount by PID calculation or the like so that the hot water temperature detected by the hot water temperature sensor 31 becomes the set temperature set by the remote controller 17. And the rotation control of the combustion fan 8 is performed to control the hot water supply operation in the hot water supply mode.
[0010]
With this control, the temperature of the hot water supply is gradually raised and reaches the set temperature of the hot water supply, but the hot water temperature does not rise immediately after gas ignition, and the hot water tap is opened as shown by the characteristic line c in FIG. In addition, it takes time to ignite, and after the gas has ignited, it takes time until the heat from gas combustion is transferred from the hot water heat exchanger 15 to the water passing through the hot water heat exchanger 15. After passing the hot water temperature rise time B from when the hot water tap is opened until the hot water temperature of the incoming water rises, the hot water temperature gradually rises and reaches the set hot water temperature and becomes stable. It should be noted that the change in the hot water temperature shown in the characteristic line c in the figure is the case where the hot water heater is cold started, that is, the hot water tap is opened only after the hot water heater is installed, or after the hot water combustion is stopped, for example, This shows the case where re-bathing is performed after a long period of time for the appliance to cool down.
[0011]
Further, in this type of hot water supply device, the control device 18 opens the hot water injection valve 35 such as an electromagnetic valve, thereby recirculating hot water produced on the hot water supply heat exchanger 15 side into the bathtub through the circulation path 25. It is equipped with a hot water filling mode operation function that drops and fills the water. This automatic hot water filling operation is performed by a command from the remote controller 17 or the like, and when the hot water level reaches the set water level set by the remote controller 17 or the like by the pressure sensor 34, the hot water filling valve 35 is closed and the hot water filling is stopped. Then, the circulation pump 23 is started and the operation in the reheating mode is performed.
[0012]
In this reheating operation, the control device 18 first rotates the circulation pump 23 in the recirculation circuit 25 to circulate hot water in the bathtub through the recirculation circuit 25. When the reheating water switch detects the flow of hot water, the control device 18 rotates the combustion fan 8, opens the solenoid valve, and burns the bath burner 6 by the point ignition by the igniter electrode 27a to reheat the heat. The circulating hot water passing through the exchanger 16 is heated to replenish the hot water in the bathtub.
[0013]
[Problems to be solved by the invention]
By the way, in this type of hot water supply apparatus, after the hot water supply combustion operation is stopped, the amount of heat held in the hot water supply heat exchanger 15 is transferred to the hot water remaining in the hot water supply heat exchanger 15 and the hot water temperature rises. Due to this phenomenon, the remaining hot water temperature in the hot water supply heat exchanger 15 becomes higher than the hot water supply set temperature, and then decreases due to natural cooling. On the other hand, at the time of re-watering, the hot water supply heat exchanger 15 is filled with water, and this water is heated by the hot water supply burner 5 so that the hot water temperature (water temperature) is as shown in FIG. It rises as shown by the characteristic line c.
[0014]
Therefore, as shown in the figure, the hot water temperature rise time B from the start of hot water supply indicated by this characteristic line c, and the remaining hot water temperature of the hot water heat exchanger 15 from the start of hot water supply of the re-drained water to the set hot water temperature. When the post-boiling time A until the start (the post-boiling time A is a value corresponding to the amount of combustion heat before the hot water supply combustion stop and the waiting time from the hot water combustion stop to the start of re-heating) The hot water temperature drop in the hot water heat exchanger 15 and the hot water temperature rise due to combustion of the hot water burner 5 are cancelled, and the reheated hot water temperature characteristic is as shown by the characteristic line s in FIG. At the time of re-heating, hot water at a temperature slightly higher than the hot water supply set temperature is initially discharged, but then hot water at the hot water supply set temperature is immediately discharged.
[0015]
However, as shown in FIG. 7B, for example, when the post-boiling time A is a long time such as 300 seconds, the post-boiling time A is longer than the rise time B. The hot water supply burner 5 is combusted by proportional control of the gas supply amount by the PID calculation of the control device 18 or the control of only FF (feed forward), etc. in a state where the residual hot water temperature in the vessel 15 has not dropped below the hot water supply set temperature. Therefore, the temperature of the re-watering hot water is as shown by the characteristic line s in the figure, and the temperature of the hot water is considerably higher than the set temperature of the hot water supply, giving a great discomfort to the user of the hot water.
[0016]
Therefore, in order to prevent overshooting hot water that is considerably higher than the hot water supply set temperature at the time of re-heating after hot water combustion stop, the present applicant, for example, as shown by the characteristic line b in FIG. The proportional control is performed after the gas supply is performed by setting the supply gas level to the hot water supply burner 5 after the slow ignition at the time of re-heating and the minimum gas level lower than the supply gas level to the hot water supply burner 5 at the time of the slow ignition. I thought about doing gas supply by. If it does in this way, as shown to the characteristic line c of the figure, the hot water temperature rise time B of the incoming hot water temperature from the start of hot water supply will become long, and this hot water temperature rise time B _R And the post-boiling time A coincide with each other, as in the case where the post-boiling time A shown in FIG. 7A is short, it is possible to prevent the overshooting of hot water that is considerably higher than the hot water supply set temperature. it can.
[0017]
Note that the gas supply time at the minimum gas level after this slow ignition is obtained by, for example, calculating the post-boiling time A from the amount of combustion heat before the hot water combustion stop and the standby time from the hot water combustion stop to the start of re-heating, It is set to a time (AB) obtained by subtracting a hot water temperature rising time B (preliminarily obtained by experiment etc.) at the cold start from the post-boiling time A.
[0018]
However, in a combined hot water supply apparatus of the type in which hot water supply burner combustion and bath burner combustion are supplied and exhausted by a common combustion fan 8 as shown in FIG. 4, hot water supply combustion on the hot water supply burner 5 side during combustion of the bath burner 6. In order to forcibly exhaust the air in the chamber 3 with the combustion fan 8, if the bath burner combustion is performed before the re-heating of hot water after the hot water supply combustion is stopped, the scavenging of the combustion fan 8 accompanying the combustion of the bath burner is performed. Thus, the hot water supply heat exchanger 15 is cooled, and the residual hot water temperature characteristic in the hot water supply heat exchanger 15 becomes as shown by the characteristic line a in FIG. 6B, and the boiling time obtained by calculation as described above Actual after-boiling time A rather than A (after-boiling time when bath burner combustion is not performed) _R Becomes shorter. Then, hot water rise time B _R After boiling time A _R Is shorter.
[0019]
When this happens, the rise in hot water temperature due to combustion of the hot water supply burner 5 cannot catch up with the drop in hot water temperature in the hot water supply heat exchanger 15. There was a problem in that undershoot hot water that was considerably lower than the set temperature appeared and the hot water temperature fluctuated, causing discomfort to the user of the hot water.
[0020]
The present invention has been made to solve the above-described problems, and its purpose is to provide a combined hot water supply apparatus that can suppress hot water temperature overshoot and undershoot during re-heating after hot water combustion stop and can use hot water comfortably. It is to provide.
[0021]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides means for solving the problems by the following configuration. That is, the present invention includes a hot water supply burner that performs heating and combustion of a hot water supply heat exchanger, a bath burner that performs heating and combustion of a reheating heat exchanger, and a common or individual that performs supply and exhaust of the hot water supply burner combustion and bath burner combustion. In a combined hot water supply apparatus of the type in which the combustion chamber on the hot water supply burner side is forcibly exhausted by a combustion fan during combustion of the bath burner, the hot water supply heat exchanger associated with the combustion of the bath burner is provided. Hot water supply side heat storage loss detection unit that estimates and detects the amount of heat released by forced exhaust scavenging, and the hot water supply side heat storage loss amount for the hot water burner for the set time after mild ignition at the time of re-heating after hot water combustion stop A gas supply level control means for setting to a larger value as the detected heat radiation amount detected by the detection unit increases, and setting to a smaller value as the detected heat radiation amount decreases, and controlling It is provided is configured as characterized.
[0022]
Further, the hot water supply side heat storage loss amount detection unit is configured to detect the amount corresponding to the combustion time of the bath burner performed from the hot water combustion stop to the start of re-heating, as the detected heat release amount of the hot water heat exchanger, The gas level control time by the supply level control means is defined as the after-boiling time until the residual hot water temperature of the hot water heat exchanger decreases to the set hot water temperature from the start of hot water supply for re-draining, and the hot water temperature at the hot water supply side from the start of hot water supply. It is also a characteristic configuration of the present invention that there is provided a level control time setting means after slow ignition that is set based on the difference from the rise time of the hot water temperature until it rises.
[0023]
In the present invention configured as described above, the hot water-side heat storage loss amount detection unit estimates and detects the amount of heat released by forced exhaust scavenging of the hot water heat exchanger accompanying the bath burner combustion, and based on this detected amount of heat released, the gas supply level control The gas supply level control by means is performed. This control is performed for a set time after the mild ignition at the time of re-heating after hot water combustion stop, and the gas supply to the hot water burner is increased as the detected heat release amount detected by the hot water side heat storage loss amount detection unit increases. The level is set to a large value, and the gas supply level to the hot water supply burner is set to a small value and controlled as the detected heat release amount decreases.
[0024]
That is, in the present invention, bath burner combustion is performed before hot water discharge after hot water combustion is stopped, and even if the hot water supply heat exchanger is dissipated by forced exhaust scavenging accompanying the bath burner combustion, As the amount of heat released increases, the gas supply level to the hot water supply burner that is supplied for the set time after the soft ignition at the time of re-draining is set and controlled by the amount corresponding to the earlier timing of the drop of the residual hot water temperature in the hot water heat exchanger. As the temperature of the incoming hot water rises earlier, the decrease in the residual hot water temperature is compensated for by the increase in hot water temperature due to combustion of the hot water burner, so that the temperature control for re-exposed hot water is controlled and the above problems are solved. The
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the present embodiment, the same reference numerals are assigned to the same name portions as in the conventional example, and the duplicate description thereof is omitted. The combined hot water supply apparatus according to the present embodiment is configured in substantially the same manner as the conventional combined hot water supply apparatus shown in FIG. 4. This is to provide a unique circuit for performing the stabilization control of the hot water temperature when the hot water is discharged.
[0026]
As shown in FIG. 1, this unique circuit includes a hot water combustion control unit 43, an elapsed time measuring unit 44, a post-boiling time calculating unit 45, a memory unit 47, a gas supply level control unit 46, and a level control time setting after a slow ignition. A means 49, a bath combustion control unit 48, a bath combustion time measurement unit 50, and a hot water supply side heat storage loss amount detection unit 51 are provided.
[0027]
The hot water supply combustion control unit 43 takes in signals from the hot water temperature sensor 32, the incoming water temperature sensor 31, the flow rate sensor 41, the remote controller 17, etc., and performs the hot water supply operation control in the hot water supply mode and the hot water filling mode operation control as described above. The bath combustion controller 48 performs hot water replenishment operation control and the like, and these control operations are the same as those in the conventional example, and therefore, a duplicate description thereof is omitted.
[0028]
The elapsed time measuring means 44 takes in the hot water combustion stop signal from the hot water combustion control unit 43 and the incoming water signal from the flow rate sensor 41, measures the elapsed time from the hot water combustion stop to the time of re-heating, and waits until re-heating. The time is added to the post-boiling time calculation unit 45 as time.
[0029]
The post-boiling time calculation unit 45 calculates the post-boiling time from the start of hot water supply for re-extruding hot water until the residual hot water temperature of the hot water heat exchanger 15 drops to the set hot water temperature when the bath burner combustion is not performed during the standby time. A is obtained. After that, when calculating the boiling time A, the memory unit 47 re-starts from the set temperature of hot water supply before stopping hot water combustion, the incoming water temperature, the amount of combustion heat (combustion capacity) determined by the incoming water amount, the temperature in the appliance, the hot water combustion after the stop of combustion. Corresponding post-boiling time data when various factors such as the elapsed time (waiting time) until the hot water are changed are given. The post-boiling time calculation unit 45 includes this data, the value of the combustion heat amount before the hot water supply combustion stop applied from the hot water supply combustion control unit 43, the value of the standby time applied from the elapsed time measuring means 44, the in-appliance temperature detection sensor (FIG. The post-boiling time A when the bath burner combustion is not performed during the standby time is calculated based on the temperature in the appliance taken in from (not shown), and is added to the level control time setting means 49 after the slow ignition.
[0030]
The post-slow ignition level control time setting means 49 includes a post-boiling time A (calculated value) added from the post-boiling time calculation unit 45 and a hot water supply side from the start of hot water supply at the cold start to the memory unit 47 in advance. Based on the difference with the hot water temperature rise time B until the hot water temperature of the incoming water rises, the gas level control time (set time) by the gas supply level control means 46 performed after the soft ignition at the time of re-heating the hot water after the hot water combustion stop It is to set. The level control time setting means 49 after the soft ignition includes a gas level control time T by the gas supply level control means 46. _C (T _C = A−B) is given, and the post-slow ignition level control time setting means 49 obtains a value obtained by subtracting the hot water temperature rise time B from the post-boiling time A by this arithmetic expression, and this value is the gas level control. It adds to the gas supply level control means 46 as time. When the value of (A−B) becomes 0 or less, the gas level control time after the slow ignition is not set.
[0031]
The bath combustion time measuring unit 50 receives the hot water combustion stop signal from the hot water combustion control unit 43, the incoming signal from the flow sensor 41, and the combustion start signal and combustion stop signal from the bath combustion control unit 48, and stops hot water combustion. From this time, the combustion time of the bath burner 6 performed from the start of re-watering is measured, and this measurement time is added to the hot water supply side heat storage loss detection unit 51.
[0032]
The hot water supply side heat storage loss amount detection unit 51 estimates and detects the amount of heat released by forced exhaust scavenging of the hot water supply heat exchanger 15 due to the combustion of the bath burner 6. In this embodiment, the hot water supply side heat storage loss amount detection is performed. The unit 51 receives the value of the bath combustion measurement time from the bath combustion time measurement unit 50, and calculates the amount corresponding to the combustion time of the bath burner 6 performed from the hot water combustion stop to the start of re-heating. The detection heat amount is detected. The hot water supply side heat storage loss amount detection unit 51 adds the detected value of the detected heat release amount to the gas supply level control means 46.
[0033]
The gas supply level control means 46 receives the value of the gas level control time applied from the post-slow ignition level control time setting means 49, and after the slow ignition at the time of re-heating after hot water combustion stop, this set gas level Control time T _C Only the gas supply level to the hot water supply burner 5 is set and controlled. In this setting control, the gas supply level control means 46 controls the gas supply level to a larger value as the detected heat release amount detected by the hot water supply side heat storage loss amount detection unit 51 increases, and the detected heat release amount is The gas supply level is set to a smaller value and controlled as it decreases.
[0034]
In order to accurately control the gas supply level by the gas supply level control means 46, in this embodiment, as shown in FIG. 3 (a), it corresponds to the combustion time of the bath burner 6 during the standby time. As the combustion time becomes longer (as the amount of heat released by the hot water supply side heat storage loss detection unit 51 becomes larger), the graph data for setting the gas supply level to the hot water supply burner 5 in a stepwise manner is the gas supply level control. Given to means 46.
[0035]
Based on the graph data, the gas supply level control means 46 performs gas supply level control according to the bath burner combustion time during the standby time. That is, as the burn time of the bath burner is longer, and as a result, the amount of heat released from the hot water heat exchanger 15 by forced exhaust air sweeping of the combustion fan 8 increases (as the value increases), the hot water is supplied at the set time after the slow ignition at the re-heating. The gas supply level to be supplied to the burner 5 is set to a large value step by step, the bath burner combustion time during the standby time is short, and as the heat release amount becomes smaller (smaller), the set time after the slow ignition is reached. The gas supply level supplied to the hot water supply burner 5 is set to a small value in a stepwise manner to control the valve opening amount of the gas proportional valve 38.
[0036]
The present embodiment is configured as described above, and in the present embodiment as well, the control device 18 performs control operations in the hot water supply mode, the hot water filling mode, the reheating mode, and the like, as in the conventional example. Control operations such as the hot water supply mode and the hot water filling mode are performed by the hot water supply combustion control unit 43, and the operation in the reheating mode is performed by the bath combustion control unit 48.
[0037]
In the present embodiment, the hot water temperature stabilization control at the time of re-watering after the hot water supply combustion stop is performed as follows. When hot water combustion is stopped, a hot water combustion stop signal is applied to the elapsed time measuring means 44, the post-boiling time calculating unit 45, and the bath combustion time measuring unit 50, respectively. Then, the elapsed time measuring means 44 measures the waiting time from when the hot water supply combustion stop signal is applied until the incoming water signal from the flow rate sensor 41 is applied, that is, from when hot water combustion stops to when the hot water is discharged again. Add to time calculator 45.
[0038]
On the other hand, when the post-boiling time calculation unit 45 receives the hot water supply combustion stop signal, it calculates the amount of combustion heat before the hot water supply combustion stop signal together with the hot water supply combustion stop signal, and the in-appliance temperature detection sensor (not shown) In addition, the remaining hot water temperature of the hot water supply heat exchanger 15 when the bath burner combustion is not performed during the standby time in response to the value of the standby time applied from the elapsed time measuring means 44 is received. The post-boiling time A is calculated and added to the post-slow ignition level control time setting means 49.
[0039]
Then, the post-slow ignition level control time setting means 49 obtains the difference (A−B) between the subsequent boiling time A and the hot water temperature rise time B at the cold start given in advance to the memory unit 47. Gas supply level control time T after slow ignition _C And is added to the gas supply level control means 46.
[0040]
On the other hand, after the hot water combustion stop signal from the hot water combustion control unit 43 is applied to the bath combustion time measuring unit 50, the bath combustion time measuring unit 50 measures the combustion time of the bath burner 6 during the standby time, This measured value is added to the hot water supply side heat storage loss amount detection unit 51, and this value is added as the detected heat release amount of the hot water supply heat exchanger 15 from the hot water supply side heat storage loss amount detection unit 51 to the gas supply level control means 46. The burning time of the bath burner 6 during the waiting time is performed by taking a bath burning start signal and a bath burning stop signal from the bath burning control unit 48 by the bath burning time measuring unit 50.
[0041]
The gas supply level control means 46 is a value of the detected heat release amount of the hot water supply heat exchanger 15 added from the hot water supply side heat storage loss amount detection unit 51, that is, the combustion time of the bath burner 6 during the standby time in this embodiment, For example, comparison with graph data as shown in FIG. 3A given to the gas supply level control means 46 is performed. When the bath burner 6 is not burned at all during the standby time, as shown in FIG. 6 (b), the hot water temperature stabilization at the time of re-heating in the apparatus previously proposed by the present applicant is performed. As with the control, the set time after the slow ignition during re-heating (gas supply level control time T _C ), The valve opening amount of the gas proportional valve 38 is controlled so that the gas supply level to the hot water supply burner 5 becomes the minimum level, and the proportional control of the gas supplied to the hot water supply burner 5 is performed after this set time has elapsed. Is called. By this control, the after-boiling time A of the hot water supply heat exchanger 15 after re-heating and the rise time B of the incoming water temperature _R When the hot water is discharged again, hot water at a hot water supply set temperature is discharged after hot water is heated slightly higher than the hot water supply set temperature during the post-boiling time A.
[0042]
Further, when the combustion of the bath burner 6 is performed during the standby time after the hot water supply combustion stop, the gas supply level control corresponding to the combustion time of the bath burner 6 is performed. For example, the bath burner combustion time during the standby time is short, and as shown by the characteristic line a in FIG. 2A, the remaining hot water temperature drop in the hot water supply heat exchanger 15 due to the forced exhaust scavenging accompanying the bath burner combustion. Is a small ratio, and the ratio of shortening the post-boiling time (AA) _R ) Is small, the gas supply level control means 49 sets the gas supply level supplied to the hot-water supply burner 5 to a small value based on the control data shown in FIG. The gas supply level is controlled as shown by the characteristic line b in FIG.
[0043]
Then, as shown by the characteristic line c in the figure, the gas supply level control time T is set such that the rise in the hot water temperature of the incoming water to the hot water supply heat exchanger 15 is indicated by the characteristic line c. _C Hot water temperature rise time B when the gas level inside is the minimum level _R Time B earlier than ' _R The temperature of the incoming hot water to the hot water supply heat exchanger 15 by the proportional control of the gas supply level to the hot water supply burner 5 _S As shown in the characteristic line s in the same figure, the hot water at a stable hot water temperature is discharged without causing an undershoot in the hot water temperature and a significant overshoot.
[0044]
On the other hand, the combustion time of the bath burner 6 during the standby time is long, and, for example, as shown by the characteristic line a in FIG. 2B, the remaining in the hot water heat exchanger 15 by the forced exhaust scavenging accompanying the combustion of the bath burner. When the rate of the decrease in hot water temperature is large, the supply gas level supplied to the hot water supply burner 5 is large by the gas supply level control means during the set time after the mild ignition at the time of re-heating, as shown by the characteristic line b in FIG. The valve opening amount of the gas proportional valve 38 is controlled by setting the value. Then, as shown by the characteristic line c in the figure, the hot water temperature of the water entering the hot water supply heat exchanger 15 is changed to the gas supply level control time T _C Hot water temperature rise time B when the gas level inside is the minimum level _R Time B earlier than ' _R Therefore, the decrease in the residual hot water temperature in the hot water heat exchanger 15 due to the forced exhaust air sweep is compensated by the increase in the incoming hot water temperature, and as shown in the characteristic line s in FIG. The temperature is approximately equal to the hot water supply set temperature and is discharged.
[0045]
According to the present embodiment, the above operation sets the gas level control time after slow ignition for adjusting the gas supply level to the hot water supply burner 5 after the slow ignition at the time of re-heating after hot water combustion stop, and this set time For this reason, the gas supply level to the hot water supply burner 5 is set to a larger value as the amount of heat released by forced exhaust scavenging of the hot water supply heat exchanger 15 increases, and is set to a smaller value as the amount of released heat decreases. The bath burner 6 is combusted during the standby time from when hot water combustion is stopped to when the hot water is discharged again, and forced exhaust sweeping is performed along with the bath burner combustion, and the hot water supply heat exchanger 15 is dissipated. However, it becomes possible to make up for the influence of this heat dissipation by the rate of combustion of the hot water supply burner 5 after the mild ignition, and hot water with a hot water temperature substantially equal to the hot water supply set temperature can be performed.
[0046]
In addition, this invention is not limited to the said embodiment example, Various aspects can be taken. For example, in the above embodiment, the gas supply level control means 46 increases the gas supply level to the hot water supply burner 5 stepwise as the bath burner combustion time increases as shown in FIG. Although the graph data to be set is given, as shown in (b) of the figure, the graph data for setting the gas level continuously high as the bath burner combustion time increases may be given. Further, table data, an arithmetic expression, or the like may be given instead of these graph data.
[0047]
In the above embodiment, the gas supply level control means 46 is directly supplied with the control data of the gas level supplied to the hot water supply burner 5 during the set time after the mild ignition at the time of re-heating. The data may be stored in the memory unit 47, and the stored data may be taken in by the gas supply level control means 46 to perform the gas supply level control.
[0048]
Further, in the above embodiment example, the post-boiling time calculating unit 45 stores the data of the post-boiling time when the factors such as the previous combustion heat quantity, the temperature in the appliance, the standby time, etc. before stopping the hot water combustion stored in the memory unit 47 are changed. However, instead of these data, an arithmetic expression for calculating the post-boiling time based on each factor is given to the memory unit 47 etc., and the post-boiling time is calculated based on this arithmetic expression. The time may be calculated.
[0049]
Further, in the above-described embodiment, the hot water supply side heat storage loss amount detection unit 51 performs the heat dissipation of the hot water supply heat exchanger 15 by forced exhaust scavenging associated with the combustion of the bath burner during the standby time. 6 is detected as an amount corresponding to the combustion time of 6, for example, the hot water supply heat exchanger 15 when various factors such as the bath burner combustion time, the temperature in the appliance, and the waiting time are changed in the memory unit 47 and the like. In addition to the combustion time of the bath burner 6 during the standby time, in addition to the data of the amount of heat released and the calculation formula for determining the amount of heat released by each factor, The amount of heat release may be detected.
[0050]
Further, the hot water supply side heat storage loss detection unit 51 is in a standby time such as whether the bath burner 6 is burned in the first half of the standby time or whether the bath burner 6 is burned in the second half of the standby time. The amount of heat released from the hot water supply heat exchanger 15 may be corrected according to the timing of combustion of the bath burner.
[0051]
Further, in the above embodiment, the gas proportional valve 38 is provided in the common gas supply passage 36 that guides the gas to the hot water burner 5 and the bath burner 6, and the opening amount of the gas proportional valve 38 is adjusted, thereby The gas supply level to the burner 5 is controlled. For example, as shown by 38a and 38b in FIG. 4, a gas proportional valve is provided on the branch side of the gas supply passage 36, and the gas proportional valve on the hot water supply burner 5 side is provided. The gas supply level to the hot water supply burner 5 may be controlled by adjusting the valve opening amount of 38a.
[0052]
Further, in the above embodiment, the exhaust port 42a of the hot water supply combustion chamber 3 and the exhaust port 42b of the bath combustion chamber 4 are provided separately, and the exhaust ports 42a and 42b are guided to the common exhaust passage 33. The composite hot water supply apparatus of the invention is also applied to a composite hot water supply apparatus in which the exhaust ports of the hot water supply combustion chamber 3 and the bath combustion chamber 4 are used as the supply exhaust ports 42, as shown in FIG. 5D, for example. .
[0053]
Furthermore, in the above embodiment, the common combustion fan 8 is provided on the other side of the hot water supply burner 5 and the bath burner 6, but the combined hot water supply apparatus of the present invention is, for example, from (a) to (c) of FIG. As shown in FIG. 4, the present invention is also applied to a combined hot water supply apparatus in which a combustion fan 8a for supplying and exhausting the hot water supply burner 5 and a combustion fan 8b for supplying and exhausting the bath burner 6 are separately provided. The present invention is widely applied to a composite hot water supply device of the type in which the inside of the combustion chamber 3 on the hot water supply burner 5 side during combustion is forcibly exhausted by a combustion fan.
[0054]
Furthermore, in the above-described embodiment, the hot water supply combustion chamber 3 that combusts the hot water supply burner 5 and the bath combustion chamber 4 that combusts the bath burner 6 are combined in a single appliance case. The composite hot water supply apparatus of the present invention is provided with an appliance provided with a hot water combustion chamber and an appliance provided with a bath combustion chamber separately. For example, these exhaust ports are also used by guiding them to a common exhaust passage. If it is a combined hot water supply device of the type that forcibly exhausts and sweeps the air in the combustion chamber 3 on the hot water supply burner 5 side by the combustion fan 8 during the combustion of the bath burner 6, even if the hot water combustion chamber 3 and the bath combustion The chamber 4 may be spaced apart.
[0055]
【The invention's effect】
According to the present invention, the heat dissipation amount of the hot water supply heat exchanger accompanying the forced exhaust air sweeping by the combustion fan in the combustion chamber on the hot water supply burner side during the bath burner combustion is estimated and detected, and the hot water supply combustion is based on the detected heat dissipation amount Since the gas supply level supplied to the hot water burner is set and controlled during the set time after the slow ignition at the time of re-heating after the stop, the set time after the slow ignition increases as the detected heat release amount increases. By setting the gas supply level to the hot water supply burner to a large value and setting the supply gas level to a small value as the detected heat dissipation amount decreases, the heat dissipation amount of the hot water supply heat exchanger increases as the heat dissipation amount increases. The decrease in the remaining hot water temperature can be compensated by the increase in the hot water temperature due to combustion of the hot water burner performed in proportion to the gas supply level.
[0056]
Therefore, even if the burner combustion is performed during the standby time after the hot water supply combustion stops and the hot water supply heat exchanger increases, the gas supply level during the set time after the slow ignition is increased. By doing so, it is possible to prevent the hot water of the undershoot from being discharged without catching up the rise in the temperature of the hot water in the heat exchanger, and the bath burner combustion is not performed during the standby time. Even if the amount of heat dissipated by the hot water heat exchanger due to the combustion of the bath burner is small, the temperature of the hot water in the hot water heat exchanger is increased by reducing the gas supply level during the set time after the soft ignition. It is also possible to suppress the occurrence of overshooting hot water that is too large and is considerably higher than the hot water supply set temperature.
[0057]
Further, according to the present invention, the hot water supply side heat storage loss amount detection unit detects the amount corresponding to the combustion time of the bath burner performed from the hot water combustion stop to the re-start of hot water as the detected heat release amount of the hot water heat exchanger. For example, it is possible to easily and accurately detect the amount of heat detected by the hot water supply heat exchanger by forced exhaust sweeping during bath burner combustion during the standby time, and stabilize the temperature of the hot water at the time of re-heating. Control can be performed easily and accurately.
[0058]
Further, the gas level control time by the gas supply level control means is determined as follows: the after-boiling time until the residual hot water temperature of the hot water supply heat exchanger decreases to the set hot water temperature from the start of hot water supply of re-hot water; According to the present invention, there is provided a level control time setting means after slow ignition that is set based on the difference from the hot water rise time until the hot water temperature rises. According to the present invention, the gas level control time is set by the gas supply level control means. Can be performed easily and accurately.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a re-hot water temperature stabilization control unit of an embodiment in a combined hot water supply apparatus according to the present invention.
FIG. 2 is an explanatory diagram of a re-heated water stabilization control operation based on a bath burner combustion time during the standby time in the embodiment.
FIG. 3 is a graph showing relational data between a bath burner combustion time and a gas supply level used for gas supply level control after slow ignition of the combined hot water supply apparatus according to the present invention.
FIG. 4 is a configuration diagram showing an example of a general composite hot water supply apparatus.
FIG. 5 is an explanatory view schematically showing another embodiment of the composite hot water supply apparatus according to the present invention.
FIG. 6 is an explanatory diagram showing a hot water temperature stabilization control operation and its problems at the time of re-watering by the combined hot water supply apparatus proposed previously by the present applicant.
FIG. 7 is a graph showing the hot water temperature at the time of re-draining in the conventional combined hot water supply apparatus together with the gas supply level and the hot water temperature.
[Explanation of symbols]
5 Hot water burner
6 Bath burner
38 Gas proportional valve
45 After boiling time calculator
46 Gas supply level control means
47 Memory section
49 Level control time setting means after slow ignition
50 Bath burning time measurement unit
51 Hot water storage heat storage loss detector

Claims

A hot water supply burner that performs heating combustion of the hot water supply heat exchanger, a bath burner that performs heating combustion of the reheating heat exchanger, and a common or individual combustion fan that performs supply and exhaust of the hot water supply burner combustion and bath burner combustion In the combined hot water supply apparatus of the type in which the combustion chamber on the hot water supply burner side is forcibly exhausted by a combustion fan during the combustion of the bath burner, the hot water supply heat exchanger accompanying the combustion of the bath burner is discharged by the forced exhaust scavenging. The hot water supply side heat storage loss detection unit detects the amount of heat, and the hot water supply side heat storage loss detection unit detects the gas supply level to the hot water burner for a set time after the mild ignition at the time of re-heating after hot water combustion stop. Gas supply level control means is provided for setting a larger value as the detected heat release amount increases and setting a smaller value as the detected heat release amount decreases. Composite water heater according to claim.

The hot water supply side heat storage loss amount detection unit is configured to detect an amount corresponding to the combustion time of the bath burner performed from the hot water combustion stop to the re-start of hot water discharge as a detected heat release amount of the hot water heat exchanger. The composite hot water supply apparatus according to 1.

The gas level control time by the gas supply level control means is defined as the after-boiling time from the start of reheating hot water supply until the remaining hot water temperature of the hot water heat exchanger decreases to the set hot water temperature, and the hot water temperature of the incoming water from the hot water supply to the hot water supply side The combined hot water supply apparatus according to claim 1 or 2, further comprising: a level control time setting means after mild ignition that is set based on a difference from a hot water temperature rise time until the hot water rises.