JP3834407B2

JP3834407B2 - Water heater

Info

Publication number: JP3834407B2
Application number: JP35629397A
Authority: JP
Inventors: 久恭渡辺; 寿久斉藤; 徹哉佐藤
Original assignee: 株式会社ガスター
Priority date: 1997-12-09
Filing date: 1997-12-09
Publication date: 2006-10-18
Anticipated expiration: 2017-12-09
Also published as: JPH11173668A

Description

【０００１】
【発明の属する技術分野】
本発明は、湯を作り出して給湯する給湯器に関するものである。
【０００２】
【従来の技術】
図１２には給湯器のシステム構成の一例がモデル図により示されている。この給湯器は、同図の実線に示すように、バーナ１と給湯熱交換器２を有し、給湯熱交換器２の入側には水供給源から給湯熱交換器２に水を導くための給水通路３が連通接続され、また、給湯熱交換器２の出側には給湯通路４の一端側が接続され、この給湯通路４の他端側は台所やシャワー等の給湯場所に導かれている。上記給水通路３には該通路３の水温を検出する入水サーミスタ５と、通水流量を検出する水量センサ６とが設けられ、給湯通路４には該通路４から給湯される湯水温を検出する出湯サーミスタ７が設けられている。
【０００３】
上記バーナ１には燃料ガスを導くためのガス供給通路８が連通接続されており、このガス供給通路８には該通路の開閉を行う電磁弁１０，１１と、弁開度でもってバーナ１への供給ガス量を制御する比例弁１２とが介設されている。
【０００４】
この給湯器には給湯運転を制御する制御装置１３が設けられ、この制御装置１３には給湯設定温度を設定するための給湯温度設定手段等が設けられたリモコン１４が信号接続されている。上記制御装置１３は次のように給湯運転を制御する。例えば、台所やシャワー等に導かれた給湯通路４の先端側に設けられた給湯栓（図示せず）が開栓され、給水通路３の通水が水量センサ６により検出されると、電磁弁１０，１１を開弁してガス供給通路８からバーナ１に燃料ガスを供給してバーナ燃焼を開始させ、給湯される湯温がリモコン１４に設定されている給湯設定温度となるようにバーナ１の燃焼熱量を比例弁１２の弁開度を制御することによって（つまり、バーナ１への供給燃料ガス量を制御することによって）制御し、上記バーナ燃焼火炎の熱によって給湯熱交換器２の通水が加熱されて給湯熱交換器２により湯が作られ、該湯は給湯通路４を通って所望の給湯場所に供給される。そして、給湯栓が閉栓されて給水通路３の通水停止を水量センサ６が検出すると、電磁弁１１を閉弁してバーナ１の燃焼を停止し、給湯運転を終了する。
【０００５】
【発明が解決しようとする課題】
ところで、給湯運転を停止した直後には、給湯熱交換器２の保有熱量が給湯熱交換器２に滞留している湯水に加えられて給湯熱交換器２内の滞留湯水が加熱され給湯設定温度の湯を給湯するための湯温よりも高温になる後沸き現象が発生し、このように、給湯熱交換器２内の滞留湯水に後沸きが生じている状態から給湯が開始されると、上記高温に加熱された湯が給湯して湯の利用者に高温による不快感を与えたり、火傷を負わせる等の危険があるという問題が生じる。
【０００６】
上記給湯熱交換器２内の滞留湯水に後沸きが発生している状態から給湯が開始されるという再出湯時の高温給湯の問題を回避するために、次に示すような再出湯時高温給湯防止手段が考えられる。例えば、図１２の点線に示すように、給水通路３と給湯通路４間を給湯熱交換器２を迂回して連通接続するバイパス通路１５を設け、バイパス通路１５には該通路１５の開閉を行う電磁弁により形成されたバイパス弁１６を介設し、また、給湯熱交換器２の出側には湯温を検出する熱交出側サーミスタ１７を設けておき、熱交出側サーミスタ１７により検出される湯温が予め定めた温度以上で給湯熱交換器２内の滞留湯水に後沸きが発生していると判断できる状態から給湯が開始されたときには、上記バイパス弁１６を開弁して、給湯熱交換器２から流れ出た高温湯にバイパス通路１５から水をミキシングして湯温を下げ、上記再出湯時の高温給湯の問題発生を防止することが考えられる。
【０００７】
しかしながら、バイパス通路１５から流れ出る水の単位時間当たりの流量は、給湯熱交換器２から流れ出る湯温の高低に拘らずほぼ一定であることから、給湯設定温度の湯を給湯するための給湯熱交換器の出側湯温に対する給湯熱交換器２から流れ出る湯温の上昇分（以下、オーバーシュートの大きさと記す）が小さいときには、給湯熱交換器２から流れ出た湯にミキシングする水量が過剰となり、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給湯されてしまったり、反対に、上記オーバーシュートの大きさが大きいときには、給湯熱交換器２から流れ出た湯にミキシングする水量が不足して、給湯設定温度よりも高めの湯が給湯されてしまい、給湯開始時に給湯設定温度の湯を安定供給することができないという問題が発生する。
【０００８】
この発明は、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、再出湯時にも、給湯設定温度の湯を予め定めた設定総流量でもって安定給湯することが可能な給湯器を提供することにある。
【０００９】
【課題を解決するための手段】
上記目的を達成するために、この発明は次のような構成をもって前記課題を解決する手段としている。すなわち、第１の発明は、給水通路から供給された水を加熱して湯を作り出し該湯を給湯通路に送出する給湯熱交換器と、上記給水通路と給湯通路間を上記給湯熱交換器を迂回して連通接続するバイパス通路と、該バイパス通路から流れ出た水が合流する湯側の流量を弁開度でもって制御する第１の流量制御手段と、上記バイパス通路を流れる水の流量を弁開度でもって制御する第２の流量制御手段と、上記バイパス通路の通水流量と湯側の流量との総流量を検出する総流量検出手段とを有し、バイパス通路から流れ出る水と湯側の湯とのミキシング後の湯温が予め定められた給湯設定温度になるためのバイパス通路の通水流量と湯側の流量との目標流量比を検出する目標流量比検出部と、バイパス通路の通水流量と湯側の流量との流量比を検出する流量比検出部とを備えた給湯器であって、上記流量比検出部により検出された流量比を上記目標流量比検出部により検出された目標流量比に比較する流量比比較部と；上記総流量検出手段により検出された総流量を予め定められた設定総流量に比較する総流量比較部と；上記流量比と総流量の各比較結果の組み合わせに応じて検出流量比を目標流量比に一致する方向に、かつ、検出総流量を設定総流量に一致する方向に前記第１と第２の各流量制御手段の弁開度を制御するための予め与えられている弁開度制御ルールと、上記流量比比較部と総流量比較部の各比較結果とに基づいて上記第１と第２の各流量制御手段の弁開度を前記弁開度制御ルールに従って制御して上記検出流量比が目標流量比に一致する方向に制御し併せて検出総流量が設定総流量に一致する方向に制御して給湯設定温度の湯を設定総流量でもって給湯するための流量比・総流量制御部と；が設けられている構成をもって前記課題を解決する手段としている。
【００１０】
第２の発明は、上記第１の発明の構成を備え、弁開度制御ルールは、上記検出総流量が設定総流量にほぼ等しく検出流量比が目標流量比よりも大きい場合に上記第１の流量制御手段の弁開度を予め定めた第１上限変化量を越えない範囲で開方向に小さく制御し、第２の流量制御手段の弁開度を予め定めた第２上限変化量を越えない範囲で閉方向に小さく制御する第１のルールと、検出総流量が設定総流量にほぼ等しく検出流量比が目標流量比よりも小さい場合に第１の流量制御手段の弁開度を小さく閉方向に、第２の流量制御手段の弁開度を小さく開方向にそれぞれ制御する第２のルールと、検出総流量が設定総流量よりも多くて検出流量比が目標流量比にほぼ等しい場合に第１の流量制御手段の弁開度を小さく閉方向に、第２の流量制御手段の弁開度を小さく閉方向にそれぞれ制御する第３のルールと、検出総流量が設定総流量よりも少なくて検出流量比が目標流量比にほぼ等しい場合に第１の流量制御手段の弁開度を小さく開方向に、第２の流量制御手段の弁開度を小さく開方向にそれぞれ制御する第４のルールと、検出総流量が設定総流量よりも少なくて検出流量比が目標流量比よりも大きい場合に第１の流量制御手段の弁開度を予め定めた第１下限変化量以上に開方向に大きく制御し、第２の流量制御手段の弁開度を閉方向に小さく制御する第５のルールと、検出総流量が設定総流量よりも少なくて検出流量比が目標流量比よりも小さい場合に第１の流量制御手段の弁開度を小さく閉方向に、第２の流量制御手段の弁開度を予め定めた第２下限変化量以上に開方向に大きく制御する第６のルールと、検出総流量が設定総流量よりも多くて検出流量比が目標流量比よりも大きい場合に第１の流量制御手段の弁開度を小さく開方向に、第２の流量制御手段の弁開度を大きく閉方向にそれぞれ制御する第７のルールと、検出総流量が設定総流量よりも多くて検出流量比が目標流量比よりも小さい場合に第１の流量制御手段の弁開度を大きく閉方向に、第２の流量制御手段の弁開度を小さく開方向にそれぞれ制御する第８のルールと、検出総流量が設定の総流量にほぼ等しく検出流量比が目標流量比にほぼ等しい場合には第１と第２の各流量制御手段の弁開度を変化させない第９のルールとから成る構成をもって前記課題を解決する手段としている。
【００１１】
第３の発明は、上記第１又は第２の発明の構成に加えて、目標流量比に対する検出流量比の偏差と、設定総流量に対する検出総流量の偏差とを求める偏差検出部が設けられ、上記流量比と総流量の各偏差の組み合わせを前件部とし、その偏差の組み合わせに応じた第１と第２の各流量制御手段の弁開度制御形態を後件部とした弁開度制御ルールと、上記偏差検出部により求められた流量比の偏差と総流量の偏差とに基づいたファジィ論理演算により、流量比・総流量制御部は、第１と第２の各流量制御手段の弁開度の操作量を求め、この求めた操作量に応じて第１と第２の各流量制御手段の弁開度を制御する構成をもって前記課題を解決する手段としている。
【００１２】
第４の発明は、上記第３の発明の構成を備え、弁開度制御ルールの前件部は、目標流量比に対する検出流量比の偏差の大小に応じた複数のメンバーシップ関数と、設定総流量に対する検出総流量の偏差の大小に応じた複数のメンバーシップ関数とから成り、弁開度制御ルールの後件部は、第１の流量制御手段の弁開度操作量の大小に応じた複数のメンバーシップ関数と、第２の流量制御手段の弁開度操作量の大小に応じた複数のメンバーシップ関数とから成り、偏差検出部により求められた流量比と総流量の各偏差に基づき、上記前件部のメンバーシップ関数からファジィ変数グレードを検出するグレード検出部と、検出されたファジィ変数グレードに基づいて前記弁開度制御ルールに合致した第１の流量制御手段に対応した上記後件部のメンバーシップ関数の有効面積の和集合と第２の流量制御手段に対応した後件部のメンバーシップ関数の有効面積の和集合とをそれぞれ検出する和集合検出部と、これら検出された第１と第２の各流量制御手段に対応した有効面積の和集合の重心をそれぞれ算出し、該求めた重心に基づき第１と第２の各流量制御手段の弁開度の操作量をそれぞれ検出する弁開度操作量検出部とが設けられている構成をもって前記課題を解決する手段としている。
【００１３】
上記構成の発明において、湯側の流量を制御する第１の流量制御手段と、バイパス通路の通水流量を制御する第２の流量制御手段とを設けたので、バイパス通路から流れ出た水と湯側の湯とがミキシングした後の湯温が給湯設定温度となるようにバイパス通路の通水流量と湯側の流量との流量比を、上記第１と第２の各流量制御手段の弁開度制御により、精度良く制御することができ、再出湯時であっても給湯設定温度の湯を安定供給することが可能となる。
【００１４】
その上、この発明では、上記流量比制御に併せて総流量制御を上記第１と第２の各流量制御手段の弁開度制御により行う構成を備えていることから、つまり、流量比比較部により比較された流量比の比較結果と、総流量比較部により比較された総流量の比較結果と、流量比と総流量の各比較結果の組み合わせに応じて予め与えられた弁開度制御ルールとに基づいて、検出流量比が目標流量比に一致する方向に、かつ、検出総流量が設定総流量に一致する方向に第１と第２の各流量制御手段の弁開度を制御する構成を備えていることから、給湯設定温度の湯を設定総流量でもって給湯することが可能となる。
【００１５】
【発明の実施の形態】
以下に、この発明に係る実施形態例を図面に基づき説明する。
【００１６】
この実施形態例の給湯器は図３に示すようなシステム構成を有している。図３に示すように、給湯熱交換器２が設けられ、該給湯熱交換器２の入側には水供給源から水を給湯熱交換器２に供給するための給水通路３が接続され、給湯熱交換器２の出側には給湯熱交換器２により作られた湯を所望の給湯場所に導くための給湯通路４が接続されている。上記給水通路３と給湯通路４間を給湯熱交換器２を迂回して連通接続する常時バイパス通路１８が設けられ、また、この常時バイパス通路１８との接続部Ｘよりも上流側の給水通路３と、常時バイパス通路１８との接続部Ｙよりも下流側の給湯通路４とを連通接続するバイパス通路１５が設けられている。
【００１７】
上記常時バイパス通路１８との接続部Ｙとバイパス通路１５との接続部Ｚとの間の給湯通路４には上記バイパス通路１５から流れ出た水に合流する湯側の流量Ｑyuを弁開度でもって制御する第１の流量制御手段ＧＭ１が介設され、また、上記バイパス通路１５には該通路１５を流れる水のバイパス流量Ｑbpを弁開度でもって制御する第２の流量制御手段ＧＭ２が介設されている。上記第１と第２の各流量制御手段ＧＭ１，ＧＭ２はギアモータ等の駆動源が備えられており、その駆動源によって上記弁開度を連続的に又は段階的に可変制御可能な構成となっている。
【００１８】
上記給水通路３には通水温度を検出する入水サーミスタ５が設けられ、また、バイパス通路１５との接続部Ｚよりも下流側の給湯通路４には湯側の湯温とバイパス通路１５から流れ出た水とがミキシングした後の湯温を検出する出湯サーミスタ７が設けられ、さらに、給湯熱交換器２の出側の湯温を検出する熱交出側サーミスタ１７が設けられている。
【００１９】
さらに、上記バイパス通路１５との接続部Ｗと常時バイパス通路１８との接続部Ｘとの間の給水通路３には該通路３部分の通水流量を上記湯側の流量Ｑyuとして検出する第１の流量センサＦＳ１が設けられ、また、バイパス通路１５との接続部Ｚよりも下流側の給湯通路４には給湯される給湯流量（出湯流量）Ｑを検出する総流量検出手段としての第２の流量センサＦＳ２が設けられている。
【００２０】
さらにまた、給湯熱交換器２を燃焼加熱するバーナ（図示せず）が設けられており、該バーナには燃料ガスをバーナに供給するガス供給通路（図示せず）が接続されている。
【００２１】
この給湯器には給湯運転を制御する制御装置１３が設けられ、この制御装置１３にはリモコン１４が信号接続されている。
【００２２】
この実施形態例では、給湯設定温度の湯を予め定められた設定総流量（例えば、１６リットル／min ）でもって給湯できるように上記第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御する特有な制御構成を備えたことを特徴としており、図１にはこの実施形態例において特徴的な制御構成がブロック図により示されている。この実施形態例に示す制御装置１３は、湯側温度検出部２０と、湯側流量検出部２１と、バイパス流量検出部２２と、目標流量比検出部２３と、流量比比較部２４と、流量比検出部２５と、総流量検出部２６と、偏差検出部２７と、流量比・総流量制御部２８と、総流量比較部３０と、データ格納部３５とを有して構成されている。
【００２３】
上記湯側温度検出部２０は第１の流量制御手段ＧＭ１を通る湯側の湯温を検出する制御構成を有する。上記湯側の湯温を検出する図３の点線に示すようなサーミスタ４０を設け、該サーミスタ４０により検出される湯温を湯側の湯温として検出してもよいが、この実施形態例では、部品点数の増加を抑制するために、上記サーミスタ４０を設けずに演算により湯側の湯温を検出する構成を有する。
【００２４】
湯側温度検出部２０は、入水サーミスタ５により検出された入水温度Ｔinと、熱交出側サーミスタ１７により検出される湯温Ｔout とを取り込み、これら検出温度Ｔout ，Ｔinを利用して次式（１）の演算により湯側の湯温Ｔyuを求める。
【００２５】
Ｔyu＝Ｔout ×ｍ＋Ｔin×ｎ・・・・・（１）
【００２６】
上記式（１）に示すｍは、給水通路３を通って来る給水が常時バイパス通路１８との接続部Ｘの位置で給湯熱交換器２側に流れる水量の分配率であり、ｎは上記接続部Ｘの位置で常時バイパス通路１８側に流れる水量の分配率であり、上記分配率は予め定まることから、定数として予め与えられる。例えば、給湯熱交換器２側の分配率が７０％で、常時バイパス通路１８側の分配率が３０％であるときには、ｍの値として０．７が、ｎの値として０．３がそれぞれ予め与えられる。
【００２７】
湯側温度検出部２０は、上記の如く、入水サーミスタ５により検出された入水温度Ｔinと、熱交出側サーミスタ１７により検出された給湯熱交換器出側湯温Ｔout とに基づき、上記式（１）の演算により湯側の湯温Ｔyuを求め、この求めた湯温Ｔyuの情報を目標流量比検出部２３に出力する。
【００２８】
目標流量比検出部２３には上記湯側温度検出部２０から出力された湯側の湯温Ｔyuと、リモコン１４に設定されている給湯設定温度Ｔspと、入水サーミスタ５により検出された入水温度Ｔinとの各温度情報が時々刻々と加えられ、それら温度情報に基づいて下式（２）の演算により、給湯設定温度Ｔspの湯を給湯するための湯側の流量とバイパス通路１５の流量との目標流量比Ｒsp（Ｒsp＝Ｑbp／Ｑyu）を求める。
【００２９】
Ｑbp／Ｑyu＝（Ｔyu−Ｔsp）／（Ｔsp−Ｔin）・・・・（２）
【００３０】
なお、給湯熱交換器２内の後沸きにより、リモコン１４に設定されている給湯設定温度Ｔspよりも高温の湯側の湯温Ｔyuをもつ湯側の流量Ｑyuの熱量が給湯設定温度Ｔspに低下するための放出熱量はバイパス通路１５を通る流量Ｑbpの水が入水温度Ｔinから給湯設定温度Ｔspに上昇するのに要する吸熱熱量に等しく、この熱平衡バランスの関係から上式（２）が導かれる。
【００３１】
目標流量比検出部２３は、上記の如く求められた目標流量比Ｒspの情報を後述する流量比比較部２４と偏差検出部２７に出力する。
【００３２】
湯側流量検出部２１は第１の流量制御手段ＧＭ１を通る湯側の流量Ｑyuを検出するものであり、この実施形態例では、第１の流量センサＦＳ１のセンサ出力を湯側の流量Ｑyuとして検出し、検出した湯側の流量Ｑyuの情報を流量比検出部２５に出力する。
【００３３】
バイパス流量検出部２２はバイパス通路１５を流れるバイパス流量Ｑbpを検出するものである。この実施形態例では、図３に示すように、バイパス流量Ｑbpを検出する流量センサをバイパス通路１５に設けていないので、バイパス流量検出部２２は、第１と第２の各流量センサＦＳ１，ＦＳ２のセンサ出力を取り込んで、第２の流量センサＦＳ２により検出された総流量Ｑから第１の流量センサＦＳ１により検出された湯側の流量Ｑyuを差し引くことによって、つまり、次式（３）の演算によりバイパス流量Ｑbpを求める。
【００３４】
Ｑbp＝Ｑ−Ｑyu・・・・・（３）
【００３５】
バイパス流量検出部２２は上記求めたバイパス流量Ｑbpの情報を流量比検出部２５に加える。流量比検出部２５は上記湯側流量検出部２１から加えられた湯側の流量Ｑyuと、バイパス流量検出部２２から加えられたバイパス流量Ｑbpとに基づいて、湯側の流量Ｑyuとバイパス流量Ｑbpの流量比Ｒdeを次式（４）の演算により検出し、その検出流量比Ｒdeの情報を流量比比較部２４と偏差検出部２７に出力する。
【００３６】
Ｒde＝Ｑbp／Ｑyu・・・・・（４）
【００３７】
流量比比較部２４は、上記目標流量比検出部２３から受け取った目標流量比Ｒspを、流量比検出部２５から受け取った検出流量比Ｒdeに比較し、検出流量比Ｒdeが目標流量比Ｒspよりも大きいか否か、又は、検出流量比Ｒdeが目標流量比Ｒspよりも小さいか否か、又は、検出流量比Ｒdeが目標流量比Ｒspを含む予め定めた許容幅内に入っており検出流量比Ｒdeは目標流量比Ｒspにほぼ等しいか否かを判断し、その比較結果を流量比・総流量制御部２８に出力する。
【００３８】
偏差検出部２７は、上記目標流量比検出部２３から加えられた目標流量比Ｒspから、流量比検出部２５から加えられた検出流量比Ｒdeを差し引いて、目標流量比Ｒspに対する検出流量比Ｒdeの偏差ΔＲを求め、その偏差ΔＲの情報を流量比・総流量制御部２８に加える。
【００３９】
総流量検出部２６は給湯される給湯流量（出湯流量）Ｑを検出するものであり、この実施形態例では、第２の流量センサＦＳ２のセンサ出力を総流量Ｑとして検出し、その検出した総流量Ｑの情報を偏差検出部２７と総流量比較部３０に加える。
【００４０】
データ格納部３５には予め定められた設定総流量Ｑsp（例えば、１６リットル／min ）が与えられており、総流量比較部３０は上記総流量検出部２６から加えられた検出総流量Ｑを上記設定総流量Ｑspに比較し、検出総流量Ｑが設定総流量Ｑspよりも多いか否か、又は、検出総流量Ｑが設定総流量Ｑspよりも少ないか否か、又は、検出総流量Ｑが設定総流量Ｑspを含む予め定めた許容幅内に入っており検出総流量Ｑが設定総流量Ｑspにほぼ等しいか否かを判断し、その比較結果を流量比・総流量制御部２８に加える。
【００４１】
偏差検出部２７は、上記データ格納部３５に格納されている設定総流量Ｑspから、上記総流量検出部２６により検出された総流量Ｑを差し引いて、設定総流量Ｑspに対する検出総流量Ｑの偏差ΔＱを求め、この偏差ΔＱの情報を流量比・総流量制御部２８に加える。
【００４２】
流量比・総流量制御部２８は上記流量比比較部２４による流量比の比較結果と、総流量比較部３０による総流量の比較結果と、偏差検出部２７により検出された流量比の偏差ΔＲと総流量の偏差ΔＱとに基づいて、第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御し検出流量比Ｒdeが目標流量比Ｒspに一致する方向に流量比を制御し併せて検出総流量Ｑが設定総流量Ｑspに一致する方向に総流量を制御する制御構成を有している。この実施形態例では、流量比・総流量制御部２８は、ファジィ論理演算を用いて上記第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御する。
【００４３】
流量比・総流量制御部２８は、図２に示すように、グレード検出部３１と、和集合検出部３２と、ミキシング制御部３３と、弁開度操作量検出部３４とを有して構成されている。
【００４４】
データ格納部３５には、目標流量比Ｒspと検出流量比Ｒdeの比較結果と、設定総流量Ｑspと検出総流量Ｑの比較結果に基づいて第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御するための次に示すような弁開度制御ルールが予め定め与えられている。この実施形態例では、弁開度制御ルールは第１〜第９のルールから成っている。
【００４５】
１）検出総流量Ｑが設定総流量Ｑspにほぼ等しく検出流量比Ｒdeが目標流量比Ｒspよりも大きい場合に上記第１の流量制御手段ＧＭ１の弁開度を予め定めた第１上限変化量（例えば、図４の（ｃ）に示す弁開度変化量ΔＷj1）を越えない範囲で開方向に小さく制御し、第２の流量制御手段ＧＭ２の弁開度を予め定めた第２上限変化量（例えば、図４の（ｄ）に示す弁開度変化量ΔＷj2）を越えない範囲で閉方向に小さく制御する。
【００４６】
２）検出総流量Ｑが設定総流量Ｑspにほぼ等しく検出流量比Ｒdeが目標流量比Ｒspよりも小さい場合には第１の流量制御手段ＧＭ１の弁開度を小さく閉方向に、第２の流量制御手段ＧＭ２の弁開度を小さく開方向にそれぞれ制御する。
【００４７】
３）検出総流量Ｑが設定総流量Ｑspよりも多くて検出流量比Ｒdeが目標流量比Ｒspにほぼ等しい場合に第１の流量制御手段ＧＭ１の弁開度を小さく閉方向に、第２の流量制御手段ＧＭ２の弁開度を小さく閉方向にそれぞれ制御する。
【００４８】
４）検出総流量Ｑが設定総流量Ｑspよりも少なくて検出流量比Ｒdeが目標流量比Ｒspにほぼ等しい場合に第１の流量制御手段ＧＭ１の弁開度を小さく開方向に、第２の流量制御手段ＧＭ２の弁開度を小さく開方向にそれぞれ制御する。
【００４９】
５）検出総流量Ｑが設定総流量Ｑspよりも少なくて検出流量比Ｒdeが目標流量比Ｒspよりも大きい場合に第１の流量制御手段ＧＭ１の弁開度を予め定めた第１下限変化量（例えば、図４の（ｃ）に示す弁開度変化量ΔＷk1）以上に開方向に大きく制御し、第２の流量制御手段ＧＭ２の弁開度を閉方向に小さく制御する。
【００５０】
６）検出総流量Ｑが設定総流量Ｑspよりも少なくて検出流量比Ｒdeが目標流量比Ｒspよりも小さい場合に第１の流量制御手段ＧＭ１の弁開度を小さく閉方向に、第２の流量制御手段ＧＭ２の弁開度を予め定めた第２下限変化量（例えば、図４の（ｄ）に示す弁開度変化量ΔＷk2）以上に開方向に大きく制御する。
【００５１】
７）検出総流量Ｑが設定総流量Ｑspよりも多くて検出流量比Ｒdeが目標流量比Ｒspよりも大きい場合に第１の流量制御手段ＧＭ１の弁開度を小さく開方向に、第２の流量制御手段ＧＭ２の弁開度を大きく閉方向にそれぞれ制御する。
【００５２】
８）検出総流量Ｑが設定総流量Ｑspよりも多くて検出流量比Ｒdeが目標流量比Ｒspよりも小さい場合に第１の流量制御手段ＧＭ１の弁開度を大きく閉方向に、第２の流量制御手段ＧＭ２の弁開度を小さく開方向にそれぞれ制御する。
【００５３】
９）検出総流量Ｑが設定の総流量Ｑspにほぼ等しく検出流量比Ｒdeが目標流量比Ｒspにほぼ等しい場合には第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を変化させない。
【００５４】
以上の第１〜第９のルールを記号化して記すと、以下のように表すことができる。ただし、以下に示すΔＱは設定総流量Ｑspに対する検出総流量Ｑの偏差を表し、ΔＲは目標流量比Ｒspに対する検出流量比Ｒdeの偏差を表し、Ｖ１は第１の流量制御手段ＧＭ１の弁開度を変動させるためにギアモータ等の駆動源を操作する操作量（つまり、ここでは駆動源への供給電圧）を表し、Ｖ２は第２の流量制御手段ＧＭ２の弁開度を変動させるための操作量を表し、ＮＢは閉方向に大きく弁開度を変化させることを、ＮＳは閉方向に小さく弁開度を変化させることを、ＺＯは弁開度を変化させないことを、ＰＳは開方向に小さく弁開度を変化させることを、ＰＢは開方向に大きく変化させることをそれぞれ表している。
【００５５】
１）ＩＦ ΔＱ＝ＺＯ＆ΔＲ＝ＮＢＴＨＥＮＶ１＝ＰＳ，Ｖ２＝ＮＳ
【００５６】
２）ＩＦ ΔＱ＝ＺＯ＆ΔＲ＝ＰＢＴＨＥＮＶ１＝ＮＳ，Ｖ２＝ＰＳ
【００５７】
３）ＩＦ ΔＱ＝ＮＢ＆ΔＲ＝ＺＯＴＨＥＮＶ１＝ＮＳ，Ｖ２＝ＮＳ
【００５８】
４）ＩＦ ΔＱ＝ＰＢ＆ΔＲ＝ＺＯＴＨＥＮＶ１＝ＰＳ，Ｖ２＝ＰＳ
【００５９】
５）ＩＦ ΔＱ＝ＰＢ＆ΔＲ＝ＮＢＴＨＥＮＶ１＝ＰＢ，Ｖ２＝ＮＳ
【００６０】
６）ＩＦ ΔＱ＝ＰＢ＆ΔＲ＝ＰＢＴＨＥＮＶ１＝ＮＳ，Ｖ２＝ＰＢ
【００６１】
７）ＩＦ ΔＱ＝ＮＢ＆ΔＲ＝ＮＢＴＨＥＮＶ１＝ＰＳ，Ｖ２＝ＮＢ
【００６２】
８）ＩＦ ΔＱ＝ＮＢ＆ΔＲ＝ＰＢＴＨＥＮＶ１＝ＮＢ，Ｖ２＝ＰＳ
【００６３】
９）ＩＦ ΔＱ＝ＺＯ＆ΔＲ＝ＺＯＴＨＥＮＶ１＝ＺＯ，Ｖ２＝ＺＯ
【００６４】
上記弁開度制御ルールにおける第１〜第９のルールは、具体的には、流量比の偏差ΔＲと総流量の偏差ΔＱに基づいて第１の流量制御手段ＧＭ１の弁開度を変化させるため操作量（制御量）Ｖ１を求めるための下記の表１に示すようなファジィテーブルと、流量比の偏差ΔＲと総流量の偏差ΔＱに基づいて第２の流量制御手段ＧＭ２の弁開度を変化させるため操作量（制御量）Ｖ２を求めるための下記の表２に示すようなファジィテーブルとにまとめられてデータ格納部３５に記憶されている。
【００６５】
【表１】

【００６６】
【表２】

【００６７】
また、データ格納部３５にはファジィ論理演算に使用する図４の（ａ），（ｂ），（ｃ），（ｄ）に示されるようなメンバーシップ関数が格納されている。図４の（ａ）には設定総流量Ｑspに対する検出総流量Ｑの偏差ΔＱの大小に応じたネガティブビックＮＢとゼロＺＯとポジティブビックＰＢの各前件部のメンバーシップ関数が示され、同図の（ｂ）には目標流量比Ｒspに対する検出流量比Ｒdeの偏差ΔＲの大小に応じたネガティブビックＮＢとゼロＺＯとポジティブビックＰＢの各前件部のメンバーシップ関数が示され、同図の（ｃ）には第１の流量制御手段ＧＭ１の弁開度の操作量Ｖ１の大小に応じたネガティブビックＮＢとネガティブスモールＮＳとゼロＺＯとポジティブスモールＰＳとポジティブビックＰＢの各後件部のメンバーシップ関数が示され、同図の（ｄ）には第２の流量制御手段ＧＭ２の弁開度の操作量Ｖ２の大小に応じたネガティブビックＮＢとネガティブスモールＮＳとゼロＺＯとポジティブスモールＰＳとポジティブビックＰＢの各後件部のメンバーシップ関数が示されている。
【００６８】
グレード検出部３１には、前記流量比比較部２４による流量比の比較結果と、総流量比較部３０による総流量の比較結果と、偏差検出部２７により検出された流量比の偏差ΔＲと、総流量の偏差ΔＱとの情報が加えられ、これら情報と、前記データ格納部３５に記憶されている弁開度制御ルールと前記前件部のメンバーシップ関数とに基づいて、グレード検出部３１は前記弁開度制御ルールの前件部に合致するファジィ変数グレードを上記前件部のメンバーシップ関数から検出し、そのグレードの情報は和集合検出部３２に出力され、該和集合検出部３２は、上記グレードに基づいて、前記弁開度制御ルールに合致した第１の流量制御手段ＧＭ１に対応した後件部のメンバーシップ関数の有効面積の和集合を求め、また、第２の流量制御手段ＧＭ２に対応した後件部のメンバーシップ関数の有効面積の和集合を求める。
【００６９】
具体的には、例えば、検出総流量Ｑが設定総流量Ｑspよりも少なく、その偏差ΔＱが図５の（ａ）に示すΔＱnaであるときには、図５の（ａ）に示す総流量の偏差ΔＱに対応した前件部のメンバーシップ関数に基づいて、上記総流量の偏差ΔＱnaに対応するＺＯのグレードは０．７５であり、ＮＢのグレードは０．２５である。また、検出流量比Ｒdeが目標流量比Ｒspよりも大きく、その偏差ΔＲが図５の（ｂ）に示すΔＲpaであるときには、図５の（ｂ）に示す総流量の偏差ΔＱに対応した前件部のメンバーシップ関数に基づいて、流量比の偏差ΔＲpaに対応するＺＯのグレードは０．２５であり、ＰＢのグレードは０．７５である。
【００７０】
上記総流量の偏差ΔＱnaに対応するグレードと流量比の偏差ΔＲpaに対応するグレードとに基づいて、弁開度制御ルールにおける第１〜第９の各ルールの前件部に対応するファジィ変数グレードを上記各ルール毎に次のように検出する。
【００７１】
前記弁開度制御ルールにおける第１のルールの前件部は、「ＩＦ ΔＱ＝ＺＯ＆ΔＲ＝ＮＢ」であり、総流量の偏差ΔＱnaに対応したＺＯのグレードは０．７５であるが、流量比の偏差ΔＲpaに該当するＮＢのグレードはなく、この第１のルールは無視される。
【００７２】
前記第２のルールの前件部は、「ＩＦ ΔＱ＝ＺＯ＆ΔＲ＝ＰＢ」であり、総流量の偏差ΔＱnaに対応したＺＯのグレードは０．７５であり、流量比の偏差ΔＲpaに対応したＰＢのグレードは０．７５であることから、上記総流量の偏差ΔＱnaに対応したＺＯのグレード０．７５と、流量比の偏差ΔＲpaに対応したＰＢのグレード０．７５とのうち、ミニマム演算により小さい方を、第２のルールに対応したファジィ変数グレードとして検出するが、この場合、上記総流量の偏差ΔＱnaのグレードと流量比の偏差ΔＲpaのグレードは等しいことから、グレード０．７５が第２のルールに対応したファジィ変数グレードとしてグレード検出部３１により検出される。
【００７３】
前記第２のルールの後件部は、「Ｖ１＝ＮＳ，Ｖ２＝ＰＳ」であることから、図５の（ｃ）に示す第１の流量制御手段ＧＭ１の弁開度の操作量Ｖ１に対応したＮＳのメンバーシップ関数を上記検出されたグレード０．７５の位置で頭切りし、図５の（ｃ）に示す領域ＡＢ０Ｃの面積が有効面積として求められ、また、図５の（ｄ）に示す第２の流量制御手段ＧＭ２の弁開度の操作量Ｖ２に対応したＰＳのメンバーシップ関数を上記検出されたグレード０．７５の位置で頭切りし、図５の（ｄ）に示す領域ａｂｃ０の面積が有効面積として求められる。
【００７４】
また、第３のルールの前件部は、「ＩＦ ΔＱ＝ＮＢ＆ΔＲ＝ＺＯ」であり、総流量の偏差ΔＱnaに対応したＮＢのグレードは図６の（ａ）に示すグレード０．２５であり、流量比の偏差ΔＲpaに対応したＺＯのグレードは図６の（ｂ）に示すグレード０．２５であることから、前述したように、ミニマム演算によりグレード０．２５が第３のルールのグレードとして検出される。
【００７５】
第３のルールの後件部は「Ｖ１＝ＮＳ，Ｖ２＝ＮＳ」であることから、上記検出されたグレード０．２５に基づいて、第１の流量制御手段ＧＭ１の弁開度の操作量Ｖ１に対応したＮＳのメンバーシップ関数の頭切りが行われて図６の（ｃ）に示すような領域ＤＥ０Ｃの面積が有効面積として検出され、また、第２の流量制御手段ＧＭ２の弁開度の操作量Ｖ２に対応したＮＳのメンバーシップ関数の頭切りが行われて図６の（ｄ）に示すような領域ｄｅ０ｆの面積が有効面積として検出される。
【００７６】
さらに、上記第４と第５と第６と第７の各ルールは、上記第１のルールと同様に、総流量の偏差ΔＱna又は流量比の偏差ΔＲpaに該当するグレードがなく、無視される。
【００７７】
第８のルールの前件部は、「ＩＦ ΔＱ＝ＮＢ＆ΔＲ＝ＰＢ」であり、総流量の偏差ΔＱnaに対応したＮＢのグレードは図７の（ａ）に示すグレード０．２５であり、流量比の偏差ΔＲpaに対応したＰＢのグレードは図７の（ｂ）に示すグレード０．７５であることから、前述したように、ミニマム演算によりグレード０．２５が第８のルールのグレードとして検出され、該グレード０．２５に基づき、第８のルールの後件部に該当した第１の流量制御手段ＧＭ１の弁開度の操作量Ｖ１に対応するＮＢのメンバーシップ関数の頭切りが行われて図７の（ｃ）に示すような領域ＦＧＨＩの面積が有効面積として検出され、また、第２の流量制御手段ＧＭ２の弁開度の操作量Ｖ２に対応するＰＳのメンバーシップ関数の頭切りが行われて図７の（ｄ）に示すような領域ｇｈｃ０の面積が有効面積として検出される。
【００７８】
第９のルールについても、前記同様にして、前件部のルールに従ってグレード０．２５が検出され、該検出されたグレードに基づいて、図８の（ｃ）に示すような領域ＪＫＬＨの面積が第１の流量制御手段ＧＭ１の弁開度操作量Ｖ１に対応したＺＯのメンバーシップ関数の有効面積として検出され、図８の（ｄ）に示すような領域ｉｊｋｌの面積が第２の流量制御手段ＧＭ２の弁開度操作量Ｖ２に対応したＺＯのメンバーシップ関数の有効面積として検出される。
【００７９】
そして、上記の如く第１〜第９の各ルール毎に検出された第１と第２の各流量制御手段ＧＭ１，ＧＭ２の操作量Ｖ１，Ｖ２にそれぞれ対応するメンバーシップ関数の有効面積の和集合を和集合検出部３２により求める。つまり、第１の流量制御手段ＧＭ１の弁開度操作量Ｖ１については、図９の（ｃ）に示すような領域ＡＢＥＫＬＩＦＤの面積を第１の流量制御手段ＧＭ１の弁開度操作量Ｖ１に対応する有効面積の和集合として求め、図９の（ｄ）に示す領域ａｂｃｆｄｇの面積を第２の流量制御手段ＧＭ２の弁開度操作量Ｖ２に対応する有効面積の和集合として求める。
【００８０】
和集合検出部３２は上記の如く第１と第２の各流量制御手段ＧＭ１，ＧＭ２の操作量Ｖ１，Ｖ２に対応したメンバーシップ関数の有効面積の和集合を検出した後に、該有効面積の和集合の情報を弁開度操作量検出部３４に出力する。
【００８１】
弁開度操作量検出部３４には和集合検出部３２から加えられた有効面積の和集合に基づいて該有効面積の和集合の重心を求めるための解法データが予め与えられており、弁開度操作量検出部３４は、上記受け取った有効面積の和集合の情報と上記解法データとに基づき、第１の流量制御手段ＧＭ１の弁開度操作量Ｖ１に対応した上記有効面積の和集合の図９の（ｃ）に示す重心Ｓｖ１を、また、第２の流量制御手段ＧＭ２の弁開度操作量Ｖ２に対応した上記有効面積の和集合の図９の（ｄ）に示す重心Ｓｖ２をそれぞれ求める。なお、上記有効面積の和集合の重心を求めるための解法手法には様々な手法があり、ここでは、それら手法のうちの何れの手法を用いてもよく、ここでは、その手法および上記解法データの説明は省略する。
【００８２】
弁開度操作量検出部３４は、上記求めた重心に基づいて第１の流量制御手段ＧＭ１の弁開度操作量ΔＶ１と、第２の流量制御手段ＧＭ２の弁開度操作量ΔＶ２とを検出し、上記求めた弁開度操作量ΔＶ１，ΔＶ２の情報をミキシング制御部３３に出力する。ミキシング制御部３３は弁開度操作量検出部３４により求められた操作量ΔＶ１，ΔＶ２の電圧を第１と第２の各流量制御手段ＧＭ１，ＧＭ２の駆動源に供給し、第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を変動させる。
【００８３】
この実施形態例によれば、バイパス通路１５を設け、該バイパス通路１５の通水流量を弁開度でもって制御する第１の流量制御手段ＧＭ１と、バイパス通路１５から流れ出た水が合流する湯側の流量Ｑyuを弁開度でもって制御する第２の流量制御手段ＧＭ２とを設けたので、上記第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を可変制御することによって、湯側の流量Ｑyuとバイパス流量Ｑbpの流量比を可変制御することができ、かつ、湯側の流量Ｑyuとバイパス流量Ｑbpの総流量Ｑを制御することが可能となる。
【００８４】
この実施形態例では、給湯設定温度の湯を給湯するための湯側の流量Ｑyuとバイパス流量Ｑbpの目標流量比Ｒspを求める一方で、バイパス流量Ｑbpと湯側の流量Ｑyuの流量比Ｒdeを検出し、該検出流量比Ｒdeを目標流量比Ｒspに比較した比較結果と、検出した総流量Ｑを設定総流量Ｑspに比較した比較結果と、総流量と流量比の各比較結果の組み合わせに応じて定められた弁開度制御ルールとに基づいて、第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御するので、上記流量比と総流量を共に考慮して上記第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度の制御を行うことができ、通常の給湯運転中にはもちろんのこと、給湯熱交換器２内に後沸きが発生している状態から給湯が開始される再出湯時にも、給湯設定温度の湯を設定総流量でもって精度良く安定供給することが可能である。
【００８５】
例えば、給湯設定温度の湯を給湯することができるように流量比のみを考慮して第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御した場合には、例えば、再出湯時に、流量比制御を行わない場合の図１１の（ｂ）の点線に示す給湯湯温変動に比べて、図１１の（ｂ）の実線に示すように、出湯開始後、直ちに、給湯設定温度の湯を給湯することができるようになるが、給水通路３に流れ込む水圧が予め想定された通常の水圧よりも高い地域では、図１１の（ａ）に示す出湯開始後の出湯流量の時間的変化に示すように、出湯開始直後、設定流量（設定総流量）よりも多めの流量で給湯され、反対に、水供給源の水圧が通常の水圧よりも低い地域では、出湯開始直後、設定流量よりも少なめの流量で給湯される虞がある。
【００８６】
これに対して、この実施形態例では、前記の如く、流量比と総流量を共に考慮して第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度制御が行われるので、図１０の（ａ），（ｂ）に示すように、再出湯時に、給湯開始後、瞬時に、給湯設定温度の湯を給湯することが可能となるだけでなく、出湯流量が高低に変動することなく設定流量でもって給湯することができるという優れた効果を得ることができる。
【００８７】
特に、この実施形態例では、上記第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度操作量Ｖ１，Ｖ２をファジィ論理演算により求めているので、検出流量比を目標流量比に一致させ、かつ、総流量を設定総流量に一致させることが容易となり、より一層精度良く、給湯設定温度の湯を設定総流量でもって給湯することができるようになる。
【００８８】
なお、この発明は上記実施形態例に限定されるものではなく、様々な実施の形態と採り得る。例えば、上記実施形態例では、上記第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度制御は給湯が行われている間、継続的に行われたが、再出湯時のみ行うようにしてもよい。
【００８９】
また、上記実施形態例では、図３に示すようなシステム構成をもつ給湯器を例にして説明したが、図３以外の給湯器にも本発明は適用することができる。例えば、図３では、総流量（出湯流量）Ｑを検出する第２の流量センサＦＳ２はバイパス通路１５との接続部Ｚよりも下流側の給湯通路４に設けられていたが、バイパス通路１５との接続部Ｗよりも上流側の給水通路３に設けてもよい。
【００９０】
さらに、バイパス通路１５には流量センサが設けられていなかったが、バイパス流量Ｑbpを検出するバイパス流量センサをバイパス通路１５に設けてもよい。このようにバイパス流量センサを設ける場合には、第１の流量センサＦＳ１と第２の流量センサＦＳ２のうちのどちらか一方を省略してもよい。バイパス流量センサを設け、第１の流量センサＦＳ１を省略する場合には、バイパス流量検出部２２は上記バイパス流量センサのセンサ出力をバイパス流量Ｑbpとして検出し、湯側流量検出部２１は第２の流量センサＦＳ２により検出される総流量Ｑから上記バイパス流量センサにより検出されるバイパス流量Ｑbpを差し引いて湯側の流量Ｑyuを求める。
【００９１】
また、バイパス流量Ｑbpを検出するバイパス流量センサを設け、第２の流量センサＦＳ２を省略する場合には、前記バイパス流量検出部２２は上記バイパス流量センサのセンサ出力をバイパス流量Ｑbpとして検出し、総流量検出部２６は、第１の流量センサＦＳ１により検出された湯側の流量Ｑyuと、上記バイパス流量センサにより検出されたバイパス流量Ｑbpとを合わせた流量を総流量Ｑとして検出する。
【００９２】
さらに、第１の流量センサＦＳ１や上記バイパス流量センサを設けずに総流量Ｑを検出する第２の流量センサＦＳ２のみを設けるようにしてもよく、この場合には、湯側温度検出部２０により検出される湯側の温度Ｔyuと、入水サーミスタ５により検出される入水温度Ｔinと、出湯サーミスタ７により検出される給湯温度Ｔmix と、第２の流量センサＦＳ２により検出される総流量Ｑとに基づいて、次に示す式（５）の演算により、バイパス流量検出部２２はバイパス流量Ｑbpを求め、湯側流量検出部２１は上記求められたバイパス流量Ｑbpを第２の流量センサＦＳ２により検出された総流量Ｑから差し引いて湯側の流量Ｑyuを求める。
【００９３】
Ｑbp＝（Ｔyu−Ｔin）×Ｑ／（Ｔmix −Ｔin）・・・・（５）
【００９４】
さらに、上記図３に示す給湯器の例では総流量Ｑを検出する第２の流量センサＦＳ２が設けられていたが、湯側の湯温Ｔyuと、入水温度Ｔinと、湯側の湯とバイパス通路１５の水とがミキシングした後の湯温Ｔmixと、バイパス通路１５の流量Ｑbpとを検出することができる場合には、上記第２の流量センサＦＳ２を省略してもよい。この場合には、例えば、次式（６）によって総流量Ｑを演算により求めることができる。
【００９５】
Ｑ＝（Ｔmix−Ｔin）×Ｑbp／（Ｔyu−Ｔin）・・・・・（６）
【００９６】
さらに、上記図３に示す給湯器では常時バイパス通路１８が１本設けられていたが、この常時バイパス通路１８は省略してもよいし、また、２本以上常時バイパス通路１８を設けてもよい。
【００９７】
さらに、図３に示す給湯器のシステム構成に風呂機能を備えた給湯器、例えば、図３に示すバイパス通路１５との接続部Ｚよりも下流側の給湯通路４と浴槽を連通接続する湯張り通路が設けられ、給湯熱交換器２により作られた湯を上記湯張り通路を介して落とし込む風呂の湯張り機能を備えた給湯器や、浴槽水を循環させ浴槽水の追い焚きを行うための追い焚き循環通路と、給湯熱交換器２により作られた湯を上記追い焚き循環通路を介して浴槽に落とし込む湯張り通路とを備えた風呂の追い焚き機能と湯張り機能を備えた給湯器等にも、この発明は適用することが可能である。
【００９８】
さらに、上記実施形態例では、弁開度制御ルールに示した開方向と閉方向の第１上限変化量は等しかったが、開方向の第１上限変化量と閉方向の第１上限変化量とを異なる値に設定してもよい。第２上限変化量と第１下限変化量と第２下限変化量についても同様に、開方向と閉方向とで異なる値を取るようにしてもよい。
【００９９】
さらに、上記実施形態例では、流量比・総流量制御部２８はファジィ論理演算を用いて、第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御したが、ファジィ論理演算を用いずに第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御してもよい。例えば、前記したような第１〜第９の弁開度制御ルールを予め定め与えておき、かつ、流量比の偏差ΔＲと総流量の偏差ΔＱの組み合せによって第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度操作量（変化量）を求めるための弁開度操作量検出データを予め定め与えておき、流量比・総流量制御部２８は、流量比比較部２４と総流量比較部３０の各比較結果と弁開度制御ルールとに基づいて第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度の可変方向を求め、上記流量比と総流量の各偏差と上記弁開度操作量検出データとに基づいて、第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度の変化量を求めて、第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御するようにしてもよい。
【０１００】
さらに、この発明における弁開度制御ルールは、検出流量比が目標流量比に一致する方向に、かつ、検出総流量が設定総流量に一致する方向に第１と第２の各流量制御手段の弁開度を制御するために流量比と総流量の各比較結果の組み合わせに応じて定められたものであればよく、上記実施形態例に示した弁開度制御ルールに限定されるものではない。さらに、上記実施形態例では、ファジィ論理演算に用いられるメンバーシップ関数は三角形状であったが、釣り鐘状のメンバーシップ関数を与えてもよい。
【０１０１】
さらに、上記実施形態例では、流量比・総流量制御部２８のグレード検出部３１は、流量比の偏差ΔＲのグレードと総流量の偏差ΔＱのグレードのうちの小さい方を選択するミニマム演算によりファジィ変数グレードを選択検出していたが、例えば、上記流量比の偏差ΔＲのグレードと総流量の偏差ΔＱのグレードのうちの大きい方を選択するマキシマム演算によりファジィ変数グレードを選択検出してもよいし、上記流量比の偏差ΔＲのグレードと総流量の偏差ΔＱのグレードとの平均を求めて該平均値をファジィ変数グレードを選択検出してもよく、このように、上記ミニマム演算以外の手法により、流量比の偏差ΔＲのグレードと総流量の偏差ΔＱのグレードに基づいてファジィ変数グレードを検出してもよい。
【０１０２】
さらに、上記実施形態例では、流量比・総流量制御部２８の和集合検出部３２は、例えば、弁開度制御ルールに合致する第１の流量制御手段ＧＭ１の弁開度操作量Ｖ１に対応するメンバーシップ関数の有効面積の和集合として、図９の（ｃ）に示すような領域ＡＢＥＫＬＩＦＤの面積を求めていたが、例えば、図５の（ｃ）に示す領域ＡＢ０Ｃと図６の（ｃ）に示す領域ＤＥ０Ｃと図７の（ｃ）に示す領域ＦＧＨＩと図８の（ｃ）に示す領域ＪＫＬＨの面積を合計した面積をメンバーシップ関数の有効面積の和集合として求めてもよい。第２の流量制御手段ＧＭ２の弁開度操作量Ｖ２に対応するメンバーシップ関数の有効面積の和集合についても同様である。
【０１０３】
【発明の効果】
この発明によれば、給水通路と給湯通路間を給湯熱交換器を迂回して連通接続するバイパス通路を設け、該バイパス通路から流れ出る湯側の流量を弁開度でもって制御する第１の流量制御手段と、バイパス通路の通水流量を弁開度でもって制御する第２の流量制御手段とを設けたので、上記第１と第２の各流量制御手段の弁開度を制御することによって、湯側の流量とバイパス通路のバイパス流量との流量比、および、湯側の流量と上記バイパス流量の総流量とを共に制御することが可能となる。
【０１０４】
この発明では、さらに、給湯設定温度の湯を給湯するための湯側の流量とバイパス流量の目標流量比を求め、上記流量比を検出し該検出した流量比を上記目標流量比に比較し、また、検出した総流量を設定総流量に比較し、これら流量比と総流量の比較結果と、流量比と総流量の各比較結果の組み合わせに応じて予め与えられている弁開度制御ルールとに基づいて、第１と第２の各流量制御手段の弁開度を制御して検出流量比が目標流量比に一致する方向に制御し併せて検出総流量が設定総流量に一致する方向に制御する流量比・総流量制御部を備えた構成としたので、再出湯時においても、精度良く給湯設定温度の湯を設定総流量でもって給湯することができるという画期的な効果を得ることができる。
【０１０５】
特に、ファジィ論理演算によって上記第１と第２の各流量制御手段の弁開度操作量を検出して該検出操作量に応じて上記第１と第２の各流量制御手段の弁開度を制御する構成にあっては、より一層、精度良く給湯設定温度の湯を設定総流量でもって給湯することができるようになる。
【図面の簡単な説明】
【図１】この実施形態例において特徴的な制御構成を示すブロック図である。
【図２】ファジィ論理演算を用いて第１と第２の各流量制御手段の弁開度操作量を求める流量比・総流量制御部の制御構成例を示すブロック図である。
【図３】この実施形態例に示す給湯器のシステム構成を示すモデル図である。
【図４】この実施形態例に示すファジィ論理演算に用いるメンバーシップ関数を示すグラフである。
【図５】この実施形態例に示すファジィ論理演算により第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度操作量を求める手法を示すための説明図である。
【図６】引き続き、この実施形態例に示すファジィ論理演算により第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度操作量を求める手法を示すための説明図である。
【図７】さらに、この実施形態例に示すファジィ論理演算により第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度操作量を求める手法を示すための説明図である。
【図８】さらに、この実施形態例に示すファジィ論理演算により第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度操作量を求める手法を示すための説明図である。
【図９】さらにまた、この実施形態例に示すファジィ論理演算により第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度操作量を求める手法を示すための説明図である。
【図１０】流量比と総流量を共に考慮した本実施形態例に示した手法により第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御したときの出湯流量と給湯温度の各特性データを示すグラフである。
【図１１】流量比と総流量のうちの流量比のみを考慮した手法により第１と第２の各流量制御手段ＧＭ１，ＧＭ２の弁開度を制御したときの出湯流量と給湯温度の各特性データを示すグラフである。
【図１２】従来の給湯器のシステム構成を示すモデル図である。
【符号の説明】
２給湯熱交換器
３給水通路
４給湯通路
１５バイパス通路
２３目標流量比検出部
２４流量比比較部
２５流量比検出部
２６総流量検出部
２７偏差検出部
２８流量比・総流量制御部
３０総流量比較部
３１グレード検出部
３２和集合検出部
３４弁開度操作量検出部
ＧＭ１第１の流量制御手段
ＧＭ２第２の流量制御手段
ＦＳ２第２の流量センサ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water heater that creates hot water and supplies hot water.
[0002]
[Prior art]
FIG. 12 shows a model diagram of an example of the system configuration of the water heater. This hot water heater has a burner 1 and a hot water supply heat exchanger 2 as shown by the solid line in the figure, and leads water from the water supply source to the hot water supply heat exchanger 2 on the inlet side of the hot water supply heat exchanger 2. Is connected to one end side of the hot water supply passage 4 and the other end side of the hot water supply passage 4 is led to a hot water supply place such as a kitchen or a shower. Yes. The water supply passage 3 is provided with a water thermistor 5 for detecting the water temperature of the passage 3 and a water amount sensor 6 for detecting the water flow rate, and the hot water supply passage 4 detects the temperature of hot water supplied from the passage 4. A hot water thermistor 7 is provided.
[0003]
A gas supply passage 8 for introducing fuel gas is connected to the burner 1. The gas supply passage 8 is connected to the burner 1 by electromagnetic valves 10 and 11 for opening and closing the passage, and the valve opening degree. And a proportional valve 12 for controlling the amount of supplied gas.
[0004]
This water heater is provided with a control device 13 for controlling a hot water supply operation, and a remote controller 14 provided with hot water temperature setting means for setting a hot water supply set temperature is signal-connected to the control device 13. The control device 13 controls the hot water supply operation as follows. For example, when a hot water tap (not shown) provided at the front end side of a hot water supply passage 4 led to a kitchen or a shower is opened and water flow through the water supply passage 3 is detected by a water amount sensor 6, an electromagnetic valve 10 and 11 are opened, fuel gas is supplied from the gas supply passage 8 to the burner 1 to start burner combustion, and the hot water temperature to be supplied is set to the hot water supply set temperature set in the remote controller 14. Is controlled by controlling the valve opening of the proportional valve 12 (that is, by controlling the amount of fuel gas supplied to the burner 1), and the heat of the hot water supply heat exchanger 2 is controlled by the heat of the burner combustion flame. Water is heated and hot water is made by the hot water supply heat exchanger 2, and the hot water is supplied to a desired hot water supply place through the hot water supply passage 4. When the hot water tap is closed and the water amount sensor 6 detects that the water supply passage 3 has stopped flowing, the solenoid valve 11 is closed to stop the combustion of the burner 1 and the hot water supply operation is terminated.
[0005]
[Problems to be solved by the invention]
By the way, immediately after stopping the hot water supply operation, the amount of heat retained in the hot water supply heat exchanger 2 is added to the hot water remaining in the hot water supply heat exchanger 2, and the hot water in the hot water supply heat exchanger 2 is heated to set the hot water supply set temperature. When the hot water supply is started from the state where the post boiling is generated in the hot water staying in the hot water supply heat exchanger 2 as described above, a post-boiling phenomenon occurs that becomes higher than the hot water temperature for supplying hot water. There is a problem that the hot water heated to the high temperature supplies hot water to the hot water user, causing discomfort due to the high temperature, and causing burns.
[0006]
In order to avoid the problem of high-temperature hot water supply at the time of re-draining that hot water supply is started from the state where the post-boiling has occurred in the hot water stored in the hot-water supply heat exchanger 2, Prevention measures are conceivable. For example, as shown by the dotted line in FIG. 12, a bypass passage 15 is provided that bypasses the hot water supply heat exchanger 2 and communicates between the water supply passage 3 and the hot water supply passage 4. The bypass passage 15 is opened and closed. A bypass valve 16 formed by an electromagnetic valve is interposed, and a heat exchange side thermistor 17 for detecting hot water temperature is provided on the outlet side of the hot water supply heat exchanger 2, and is detected by the heat exchange side thermistor 17. When hot water supply is started from a state where it can be determined that the boiling water has been generated in the hot water in the hot water supply heat exchanger 2 at a predetermined temperature or higher, the bypass valve 16 is opened, It is conceivable that the hot water flowing out of the hot water supply heat exchanger 2 is mixed with water from the bypass passage 15 to lower the hot water temperature, thereby preventing the occurrence of the problem of the high temperature hot water supply at the time of re-heating.
[0007]
However, since the flow rate per unit time of the water flowing out of the bypass passage 15 is substantially constant regardless of the level of the hot water flowing out of the hot water supply heat exchanger 2, the hot water supply heat exchange for supplying hot water at the hot water supply set temperature is performed. When the rise in the hot water temperature flowing out from the hot water supply heat exchanger 2 relative to the outlet hot water temperature of the water heater (hereinafter referred to as overshoot size) is small, the amount of water mixed into the hot water flowing out from the hot water heat exchanger 2 becomes excessive, When undershoot hot water that is considerably lower than the hot water supply set temperature is supplied, or conversely, when the size of the overshoot is large, the amount of water mixed with the hot water flowing out of the hot water heat exchanger 2 is insufficient. Hot water higher than the hot water supply set temperature is supplied, and there is a problem that the hot water at the hot water supply set temperature cannot be stably supplied at the start of hot water supply. .
[0008]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a water heater capable of stably supplying hot water at a preset hot water flow rate at a preset hot water supply temperature even during re-heating. It is to provide.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration as means for solving the above-mentioned problems. That is, the first invention heats the water supplied from the water supply passage to produce hot water and sends the hot water to the hot water supply passage, and the hot water supply heat exchanger between the water supply passage and the hot water supply passage. A bypass passage that bypasses and communicates, a first flow rate control means that controls the flow rate on the hot water side where water flowing out of the bypass passage joins is controlled by a valve opening, and a flow rate of water that flows through the bypass passage. Water and hot water flowing out from the bypass passage, having second flow control means for controlling by opening and total flow detection means for detecting the total flow rate of the water flow rate of the bypass passage and the hot water side A target flow rate detection unit for detecting a target flow rate ratio between the water flow rate of the bypass passage and the flow rate on the hot water side so that the hot water temperature after mixing with hot water becomes a predetermined hot water supply set temperature; The flow rate ratio between the water flow rate and the hot water flow rate A water heater having a flow rate detection unit that outputs, a flow rate comparison unit that compares the flow rate detected by the flow rate detection unit with the target flow rate detected by the target flow rate detection unit; A total flow rate comparison unit for comparing the total flow rate detected by the total flow rate detection means with a predetermined set total flow rate; according to a combination of the comparison results of the flow rate ratio and the total flow rate For controlling the valve opening degree of each of the first and second flow rate control means in a direction in which the detected flow rate ratio matches the target flow rate ratio, and the detected total flow rate matches the set total flow rate. Based on the valve opening control rules given in advance and the comparison results of the flow rate ratio comparison unit and the total flow rate comparison unit, the valve openings of the first and second flow rate control means are determined. According to the valve opening control rule For controlling the detected flow rate ratio in a direction that matches the target flow rate ratio and controlling the detected total flow rate in a direction that matches the set total flow rate to supply hot water at the set hot water temperature with the set total flow rate. The flow rate ratio / total flow rate control unit is provided as a means for solving the above problems.
[0010]
A second invention has the configuration of the first invention, and the valve opening degree control rule is that the detected first flow rate is substantially equal to the set total flow rate and the detected flow rate ratio is larger than the target flow rate ratio. The valve opening of the flow rate control means is controlled to be small in the opening direction within a range not exceeding the predetermined first upper limit change amount, and the valve opening degree of the second flow rate control means does not exceed the predetermined second upper limit change amount. The first rule that controls the range to be small in the closing direction, and when the detected total flow rate is substantially equal to the set total flow rate and the detected flow rate ratio is smaller than the target flow rate ratio, the valve opening of the first flow rate control means is reduced to the close direction In addition, the second rule for controlling the valve opening degree of the second flow rate control means to be small in the opening direction, and when the detected total flow rate is larger than the set total flow rate and the detected flow rate ratio is substantially equal to the target flow rate ratio, The first flow rate control means is opened in the closing direction with a small valve opening of the second flow rate control means. A third rule for controlling the valve opening of each valve in the closing direction, and when the detected total flow rate is less than the set total flow rate and the detected flow rate ratio is substantially equal to the target flow rate ratio, the first flow rate control means opens the valve. A fourth rule for controlling the valve opening degree of the second flow rate control means in a small direction in the opening direction with a small degree, and a detected total flow rate smaller than the set total flow rate and a detected flow rate ratio being higher than the target flow rate ratio Is larger than the predetermined first lower limit change amount, the valve opening degree of the first flow rate control means is controlled to be larger in the opening direction, and the valve opening degree of the second flow rate control means is controlled to be smaller in the closing direction. When the detected total flow rate is smaller than the set total flow rate and the detected flow rate ratio is smaller than the target flow rate ratio, the valve opening degree of the first flow rate control unit is decreased and the second flow rate control unit is closed in the closing direction. The opening of the valve is larger in the opening direction than the predetermined second lower limit change amount. The sixth rule to be controlled, and when the detected total flow rate is larger than the set total flow rate and the detected flow rate ratio is larger than the target flow rate ratio, the valve opening degree of the first flow rate control means is decreased in the opening direction, and the second A seventh rule for controlling the valve opening degree of the flow rate control means largely in the closing direction, and the first flow rate control means when the detected total flow rate is larger than the set total flow rate and the detected flow rate ratio is smaller than the target flow rate ratio. And the eighth rule for controlling the valve opening of the second flow rate control means in the closing direction and the opening amount of the second flow rate control means in the opening direction, respectively, and the detected flow rate ratio is substantially equal to the set total flow rate. When the flow rate ratio is substantially equal, the ninth rule that does not change the valve opening degree of the first and second flow rate control means is used as means for solving the above-mentioned problem.
[0011]
According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, a deviation detection unit for obtaining a deviation of the detected flow rate ratio with respect to the target flow rate ratio and a deviation of the detected total flow rate with respect to the set total flow rate is provided. A valve opening control in which the combination of each deviation of the flow rate ratio and the total flow rate is an antecedent part, and the valve opening control form of each of the first and second flow rate control means according to the combination of the deviations is a consequent part. By the fuzzy logic operation based on the rule and the deviation of the flow rate ratio and the deviation of the total flow rate obtained by the deviation detecting unit, the flow rate ratio / total flow rate control unit can control the valves of the first and second flow rate control means. An operation amount of the opening is obtained, and a means for solving the above problem is configured by controlling the valve opening of each of the first and second flow rate control means according to the obtained operation amount.
[0012]
4th invention is equipped with the structure of the said 3rd invention, The antecedent part of the valve opening degree control rule has a plurality of membership functions according to the magnitude of the deviation of the detected flow rate ratio with respect to the target flow rate ratio, It consists of a plurality of membership functions according to the magnitude of the deviation of the detected total flow rate relative to the flow rate, and the consequent part of the valve opening degree control rule is a plurality according to the magnitude of the valve opening degree manipulated variable of the first flow rate control means. And a plurality of membership functions corresponding to the magnitude of the valve opening manipulated variable of the second flow rate control means, based on the flow rate ratio obtained by the deviation detector and each deviation of the total flow rate, A grade detector for detecting a fuzzy variable grade from the membership function of the antecedent part, and the consequent corresponding to the first flow rate control means that matches the valve opening control rule based on the detected fuzzy variable grade Department of A union detecting unit for detecting a union of effective areas of the burship function and a union of effective areas of the membership function corresponding to the second flow rate control unit, and the detected first and first Calculating the center of gravity of the union of the effective areas corresponding to each of the two flow rate control means, and detecting the valve opening degree of each of the first and second flow rate control means based on the obtained center of gravity. A means for solving the above-described problem is provided with a configuration in which a degree operation amount detection unit is provided.
[0013]
In the invention having the above configuration, since the first flow rate control means for controlling the flow rate on the hot water side and the second flow rate control means for controlling the water flow rate of the bypass passage are provided, the water and hot water flowing out from the bypass passage are provided. The flow rate ratio between the water flow rate in the bypass passage and the flow rate on the hot water side is adjusted so that the hot water temperature after mixing with the hot water on the side becomes the hot water supply set temperature. By the degree control, it is possible to control with high accuracy, and it is possible to stably supply hot water at a hot water supply set temperature even at the time of re-heating.
[0014]
In addition, according to the present invention, since the total flow rate control is performed by the valve opening degree control of each of the first and second flow rate control means in addition to the flow rate ratio control, that is, the flow rate ratio comparison unit. The comparison result of the flow rate ratio compared by the above, the comparison result of the total flow rate compared by the total flow rate comparison unit, and the valve opening degree control rule given in advance according to the combination of each comparison result of the flow rate ratio and the total flow rate, Based on the above, a configuration for controlling the valve opening degree of the first and second flow rate control means in the direction in which the detected flow rate ratio matches the target flow rate ratio and in the direction in which the detected total flow rate matches the set total flow rate. Since it is provided, it becomes possible to supply hot water at a hot water supply set temperature at a set total flow rate.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the drawings.
[0016]
The water heater of this embodiment has a system configuration as shown in FIG. As shown in FIG. 3, a hot water supply heat exchanger 2 is provided, and a water supply passage 3 for supplying water from a water supply source to the hot water supply heat exchanger 2 is connected to the inlet side of the hot water supply heat exchanger 2. Connected to the outlet side of the hot water supply heat exchanger 2 is a hot water supply passage 4 for guiding the hot water produced by the hot water supply heat exchanger 2 to a desired hot water supply place. A constant bypass passage 18 is provided to connect the water supply passage 3 and the hot water supply passage 4 by bypassing the hot water supply heat exchanger 2, and the water supply passage 3 upstream of the connection portion X with the constant bypass passage 18. And a bypass passage 15 that connects the hot water supply passage 4 on the downstream side of the connection portion Y with the constant bypass passage 18.
[0017]
In the hot water supply passage 4 between the connection portion Y to the constant bypass passage 18 and the connection portion Z to the bypass passage 15, the flow rate Qyu on the hot water side joining the water flowing out from the bypass passage 15 is set as the valve opening degree. The first flow rate control means GM1 for controlling is provided, and the bypass passage 15 is provided with second flow rate control means GM2 for controlling the bypass flow rate Qbp of water flowing through the passage 15 by the valve opening degree. Has been. Each of the first and second flow rate control means GM1 and GM2 is provided with a drive source such as a gear motor, and the valve opening degree can be variably controlled continuously or stepwise by the drive source. Yes.
[0018]
The water supply passage 3 is provided with a water thermistor 5 for detecting the water flow temperature, and the hot water supply passage 4 downstream from the connecting portion Z with the bypass passage 15 flows out from the hot water temperature and the bypass passage 15. A hot water thermistor 7 for detecting the hot water temperature after mixing with the hot water is provided, and a heat exchanging thermistor 17 for detecting the hot water temperature on the outlet side of the hot water supply heat exchanger 2 is further provided.
[0019]
Further, in the water supply passage 3 between the connection portion W with the bypass passage 15 and the connection portion X with the constant bypass passage 18, a first water flow rate Qyu is detected as the flow rate Qyu on the hot water side. The flow rate sensor FS1 is provided, and the hot water supply passage 4 downstream of the connecting portion Z with the bypass passage 15 is a second flow rate detecting means for detecting the hot water supply flow rate (outflow flow rate) Q supplied with hot water. A flow sensor FS2 is provided.
[0020]
Furthermore, a burner (not shown) for burning and heating the hot water supply heat exchanger 2 is provided, and a gas supply passage (not shown) for supplying fuel gas to the burner is connected to the burner.
[0021]
The water heater is provided with a control device 13 for controlling a hot water supply operation, and a remote controller 14 is connected to the control device 13 by a signal.
[0022]
In this embodiment, the first and second flow rate control means GM1 and GM2 are opened so that hot water at a hot water supply set temperature can be supplied at a preset total flow rate (for example, 16 liters / min). A characteristic control configuration for controlling the degree is provided, and FIG. 1 is a block diagram showing a control configuration characteristic in this embodiment. The control device 13 shown in this embodiment includes a hot water temperature detector 20, a hot water flow detector 21, a bypass flow detector 22, a target flow ratio detector 23, a flow ratio comparator 24, and a flow rate. The ratio detection unit 25, the total flow rate detection unit 26, the deviation detection unit 27, the flow rate ratio / total flow rate control unit 28, the total flow rate comparison unit 30, and the data storage unit 35 are configured.
[0023]
The hot water temperature detector 20 has a control configuration for detecting the hot water temperature on the hot water side passing through the first flow rate control means GM1. The thermistor 40 as shown by the dotted line in FIG. 3 for detecting the hot water temperature on the hot water side may be provided, and the hot water temperature detected by the thermistor 40 may be detected as the hot water temperature on the hot water side. In order to suppress an increase in the number of parts, the hot water temperature on the hot water side is detected by calculation without providing the thermistor 40.
[0024]
The hot water side temperature detection unit 20 takes in the incoming water temperature Tin detected by the incoming water thermistor 5 and the hot water temperature Tout detected by the heat exchange side thermistor 17, and uses these detected temperatures Tout, Tin to The hot water temperature Tyu on the hot water side is obtained by the calculation of 1).
[0025]
Tyu = Tout × m + Tin × n (1)
[0026]
M shown in the above equation (1) is a distribution ratio of the amount of water flowing through the water supply passage 3 to the hot water supply heat exchanger 2 side at the position of the connection portion X with the bypass passage 18 at all times, and n is the connection described above. This is the distribution ratio of the amount of water that always flows to the bypass passage 18 side at the position of the portion X. Since the distribution ratio is determined in advance, it is given in advance as a constant. For example, when the distribution ratio on the hot water supply heat exchanger 2 side is 70% and the distribution ratio on the constant bypass passage 18 side is 30%, the value of m is 0.7 and the value of n is 0.3 beforehand. Given.
[0027]
As described above, the hot water temperature detector 20 is based on the incoming water temperature Tin detected by the incoming water thermistor 5 and the hot water supply heat exchanger outlet hot water temperature Tout detected by the heat exchange side thermistor 17. The hot water temperature Tyu on the hot water side is obtained by the calculation of 1), and information on the obtained hot water temperature Tyu is output to the target flow rate ratio detection unit 23.
[0028]
The target flow rate detection unit 23 includes a hot water temperature Tyu output from the hot water temperature detection unit 20, a hot water supply set temperature Tsp set in the remote controller 14, and an incoming water temperature Tin detected by the incoming water thermistor 5. And the flow rate of the hot water side for supplying hot water of the hot water supply set temperature Tsp and the flow rate of the bypass passage 15 by the calculation of the following equation (2) based on the temperature information. A target flow rate ratio Rsp (Rsp = Qbp / Qyu) is obtained.
[0029]
Qbp / Qyu = (Tyu-Tsp) / (Tsp-Tin) (2)
[0030]
The amount of heat of the hot water flow rate Qyu having the hot water temperature Tyu higher than the hot water supply temperature Tsp set in the remote controller 14 is lowered to the hot water supply temperature Tsp due to the subsequent boiling in the hot water heat exchanger 2. The amount of heat released is equal to the amount of endothermic heat required for the water having a flow rate Qbp passing through the bypass passage 15 to rise from the incoming water temperature Tin to the hot water supply set temperature Tsp, and the above equation (2) is derived from the relationship of this thermal balance.
[0031]
The target flow rate detection unit 23 outputs information on the target flow rate ratio Rsp obtained as described above to the flow rate comparison unit 24 and the deviation detection unit 27 described later.
[0032]
The hot water flow rate detector 21 detects the hot water flow rate Qyu passing through the first flow rate control means GM1, and in this embodiment, the sensor output of the first flow sensor FS1 is used as the hot water flow rate Qyu. The detected hot water side flow rate Qyu is output to the flow rate ratio detection unit 25.
[0033]
The bypass flow rate detector 22 detects the bypass flow rate Qbp flowing through the bypass passage 15. In this embodiment, as shown in FIG. 3, since the flow rate sensor for detecting the bypass flow rate Qbp is not provided in the bypass passage 15, the bypass flow rate detection unit 22 includes the first and second flow rate sensors FS1, FS2. And subtracting the hot water flow rate Qyu detected by the first flow rate sensor FS1 from the total flow rate Q detected by the second flow rate sensor FS2, that is, the calculation of the following equation (3) To obtain the bypass flow rate Qbp.
[0034]
Qbp = Q-Qyu (3)
[0035]
The bypass flow rate detection unit 22 adds information about the obtained bypass flow rate Qbp to the flow rate ratio detection unit 25. The flow rate ratio detection unit 25 is based on the hot water side flow rate Qyu applied from the hot water side flow rate detection unit 21 and the bypass flow rate Qbp applied from the bypass flow rate detection unit 22, and the hot water side flow rate Qyu and the bypass flow rate Qbp. The flow rate ratio Rde is detected by the calculation of the following equation (4), and information on the detected flow rate ratio Rde is output to the flow rate ratio comparison unit 24 and the deviation detection unit 27.
[0036]
Rde = Qbp / Qyu (4)
[0037]
The flow rate ratio comparison unit 24 compares the target flow rate ratio Rsp received from the target flow rate detection unit 23 with the detected flow rate ratio Rde received from the flow rate detection unit 25, and the detected flow rate ratio Rde is greater than the target flow rate ratio Rsp. The detected flow rate ratio Rde is smaller than the target flow rate ratio Rsp, or the detected flow rate ratio Rde is within a predetermined allowable range including the target flow rate ratio Rsp. Determines whether or not it is substantially equal to the target flow ratio Rsp, and outputs the comparison result to the flow ratio / total flow controller 28.
[0038]
The deviation detector 27 subtracts the detected flow rate ratio Rde added from the flow rate ratio detector 25 from the target flow rate ratio Rsp added from the target flow rate ratio detector 23 to obtain the detected flow rate ratio Rde relative to the target flow rate ratio Rsp. The deviation ΔR is obtained, and information on the deviation ΔR is added to the flow rate ratio / total flow rate control unit 28.
[0039]
The total flow rate detection unit 26 detects the hot water supply flow rate (outflow flow rate) Q to be supplied with hot water. In this embodiment, the sensor output of the second flow rate sensor FS2 is detected as the total flow rate Q, and the detected total flow rate is detected. Information on the flow rate Q is added to the deviation detection unit 27 and the total flow rate comparison unit 30.
[0040]
A predetermined total flow rate Qsp (for example, 16 liters / min) set in advance is given to the data storage unit 35, and the total flow rate comparison unit 30 uses the detected total flow rate Q applied from the total flow rate detection unit 26 as described above. Compared with the set total flow rate Qsp, whether the detected total flow rate Q is larger than the set total flow rate Qsp, whether the detected total flow rate Q is less than the set total flow rate Qsp, or the detected total flow rate Q is set It is determined whether the detected total flow rate Q is within a predetermined allowable range including the total flow rate Qsp and the detected total flow rate Q is substantially equal to the set total flow rate Qsp, and the comparison result is added to the flow rate ratio / total flow control unit 28.
[0041]
The deviation detection unit 27 subtracts the total flow rate Q detected by the total flow rate detection unit 26 from the set total flow rate Qsp stored in the data storage unit 35, and the deviation of the detected total flow rate Q with respect to the set total flow rate Qsp. ΔQ is obtained, and information on the deviation ΔQ is added to the flow rate ratio / total flow rate control unit 28.
[0042]
The flow rate ratio / total flow rate control unit 28 includes a flow rate comparison result obtained by the flow rate comparison unit 24, a total flow rate comparison result obtained by the total flow rate comparison unit 30, and a flow rate deviation ΔR detected by the deviation detection unit 27. Based on the deviation ΔQ of the total flow rate, the valve opening degree of each of the first and second flow rate control means GM1, GM2 is controlled, and the flow rate ratio is controlled in the direction in which the detected flow rate ratio Rde matches the target flow rate ratio Rsp. The control total flow rate Q is controlled to control the total flow rate in a direction that matches the set total flow rate Qsp. In this embodiment, the flow ratio / total flow control unit 28 controls the valve opening degree of each of the first and second flow control means GM1, GM2 using fuzzy logic operation.
[0043]
As shown in FIG. 2, the flow rate ratio / total flow control unit 28 includes a grade detection unit 31, a union detection unit 32, a mixing control unit 33, and a valve opening operation amount detection unit 34. Has been.
[0044]
The data storage unit 35 stores the first and second flow rate control means GM1 and GM2 based on the comparison result between the target flow rate ratio Rsp and the detected flow rate ratio Rde and the comparison result between the set total flow rate Qsp and the detected total flow rate Q. The following valve opening control rules for controlling the valve opening are determined in advance. In this embodiment, the valve opening degree control rule is composed of first to ninth rules.
[0045]
1) When the detected total flow rate Q is substantially equal to the set total flow rate Qsp and the detected flow rate ratio Rde is larger than the target flow rate ratio Rsp, a first upper limit change amount (the first upper limit change amount) that predetermines the valve opening degree of the first flow rate control means GM1 For example, the valve opening degree of the second flow rate control means GM2 is controlled to be small in the opening direction within a range not exceeding the valve opening degree change amount ΔWj1) shown in FIG. For example, the control is made small in the closing direction within a range not exceeding the valve opening change amount ΔWj2) shown in FIG.
[0046]
2) When the detected total flow rate Q is substantially equal to the set total flow rate Qsp and the detected flow rate ratio Rde is smaller than the target flow rate ratio Rsp, the valve opening degree of the first flow rate control means GM1 is decreased and the second flow rate is set in the closing direction. The valve opening of the control means GM2 is controlled to be small in the opening direction.
[0047]
3) When the detected total flow rate Q is larger than the set total flow rate Qsp and the detected flow rate ratio Rde is substantially equal to the target flow rate ratio Rsp, the valve opening degree of the first flow rate control means GM1 is decreased and the second flow rate is set in the closing direction. The valve opening of the control means GM2 is controlled to be small in the closing direction.
[0048]
4) When the detected total flow rate Q is smaller than the set total flow rate Qsp and the detected flow rate ratio Rde is substantially equal to the target flow rate ratio Rsp, the valve opening degree of the first flow rate control means GM1 is reduced and the second flow rate is set in the opening direction. The valve opening of the control means GM2 is controlled to be small in the opening direction.
[0049]
5) When the detected total flow rate Q is smaller than the set total flow rate Qsp and the detected flow rate ratio Rde is larger than the target flow rate ratio Rsp, the first lower limit change amount (the first lower limit change amount (1) For example, the valve opening degree of the second flow rate control means GM2 is controlled to be smaller in the closing direction by controlling the opening degree to be larger than the valve opening change amount ΔWk1) shown in FIG.
[0050]
6) When the detected total flow rate Q is smaller than the set total flow rate Qsp and the detected flow rate ratio Rde is smaller than the target flow rate ratio Rsp, the valve opening degree of the first flow rate control means GM1 is made smaller and the second flow rate is closed. The valve opening degree of the control means GM2 is largely controlled in the opening direction to be equal to or larger than a predetermined second lower limit change amount (for example, the valve opening change amount ΔWk2 shown in FIG. 4D).
[0051]
7) When the detected total flow rate Q is larger than the set total flow rate Qsp and the detected flow rate ratio Rde is larger than the target flow rate ratio Rsp, the valve opening degree of the first flow rate control means GM1 is decreased and the second flow rate is set in the opening direction. The valve opening degree of the control means GM2 is largely controlled in the closing direction.
[0052]
8) When the detected total flow rate Q is larger than the set total flow rate Qsp and the detected flow rate ratio Rde is smaller than the target flow rate ratio Rsp, the valve opening degree of the first flow rate control means GM1 is greatly increased in the closing direction, and the second flow rate is set. The valve opening of the control means GM2 is controlled to be small in the opening direction.
[0053]
9) When the detected total flow rate Q is substantially equal to the set total flow rate Qsp and the detected flow rate ratio Rde is substantially equal to the target flow rate ratio Rsp, the valve openings of the first and second flow rate control means GM1 and GM2 are not changed. .
[0054]
The above first to ninth rules can be expressed as follows by symbolizing them. However, ΔQ shown below represents a deviation of the detected total flow rate Q with respect to the set total flow rate Qsp, ΔR represents a deviation of the detected flow rate ratio Rde with respect to the target flow rate ratio Rsp, and V1 represents the valve opening degree of the first flow rate control means GM1. Represents an operation amount (that is, a supply voltage to the drive source here) for operating a drive source such as a gear motor, and V2 is an operation amount for changing the valve opening degree of the second flow rate control means GM2. NB indicates that the valve opening is greatly changed in the closing direction, NS indicates that the valve opening is changed small in the closing direction, ZO indicates that the valve opening is not changed, and PS is small in the opening direction. PB indicates that the valve opening is changed, and PB indicates a large change in the opening direction.
[0055]
1) IF ΔQ = ZO & ΔR = NB THEN V1 = PS, V2 = NS
[0056]
2) IF ΔQ = ZO & ΔR = PB THEN V1 = NS, V2 = PS
[0057]
3) IF ΔQ = NB & ΔR = ZO THEN V1 = NS, V2 = NS
[0058]
4) IF ΔQ = PB & ΔR = ZO THEN V1 = PS, V2 = PS
[0059]
5) IF ΔQ = PB & ΔR = NB THEN V1 = PB, V2 = NS
[0060]
6) IF ΔQ = PB & ΔR = PB THEN V1 = NS, V2 = PB
[0061]
7) IF ΔQ = NB & ΔR = NB THEN V1 = PS, V2 = NB
[0062]
8) IF ΔQ = NB & ΔR = PB THEN V1 = NB, V2 = PS
[0063]
9) IF ΔQ = ZO & ΔR = ZO THEN V1 = ZO, V2 = ZO
[0064]
Specifically, the first to ninth rules in the valve opening degree control rule are for changing the valve opening degree of the first flow rate control means GM1 based on the deviation ΔR of the flow rate ratio and the deviation ΔQ of the total flow rate. The valve opening degree of the second flow rate control means GM2 is changed based on a fuzzy table as shown in Table 1 below for obtaining the operation amount (control amount) V1, and the flow rate ratio deviation ΔR and the total flow rate deviation ΔQ. Are stored in the data storage unit 35 together with a fuzzy table as shown in Table 2 below for obtaining an operation amount (control amount) V2.
[0065]
[Table 1]

[0066]
[Table 2]

[0067]
The data storage unit 35 stores membership functions as shown in FIGS. 4A, 4B, 4C, and 4D used for fuzzy logic operations. FIG. 4A shows the membership functions of the antecedent parts of negative big NB, zero ZO and positive big PB according to the magnitude of deviation ΔQ of the detected total flow Q with respect to the set total flow Qsp. (B) shows the membership functions of the antecedent parts of negative big NB, zero ZO and positive big PB according to the magnitude of deviation ΔR of detected flow ratio Rde with respect to target flow ratio Rsp. c) Membership of each consequent part of negative big NB, negative small NS, zero ZO, positive small PS, and positive big PB according to the magnitude of the operation amount V1 of the valve opening degree of the first flow control means GM1. (D) of the figure shows negative big NB, negative small NS and zero according to the magnitude of the manipulated variable V2 of the valve opening degree of the second flow rate control means GM2. The membership functions of each consequent part of RO ZO, Positive Small PS, and Positive Big PB are shown.
[0068]
The grade detection unit 31 includes a comparison result of the flow rate ratio by the flow rate comparison unit 24, a comparison result of the total flow rate by the total flow rate comparison unit 30, a deviation ΔR of the flow rate ratio detected by the deviation detection unit 27, and a total Information on the deviation ΔQ of the flow rate is added, and based on these information, the valve opening degree control rule stored in the data storage unit 35, and the membership function of the antecedent part, the grade detecting unit 31 A fuzzy variable grade that matches the antecedent part of the valve opening control rule is detected from the membership function of the antecedent part, and the grade information is output to the union detection unit 32, and the union detection unit 32 Based on the above grade, the union of the effective areas of the membership functions of the consequent part corresponding to the first flow control means GM1 that matches the valve opening control rule is obtained, and the second flow control means G Find the union of the effective areas of the membership function of the consequent part corresponding to M2.
[0069]
Specifically, for example, when the detected total flow rate Q is smaller than the set total flow rate Qsp and the deviation ΔQ is ΔQna shown in FIG. 5A, the total flow rate deviation ΔQ shown in FIG. The ZO grade corresponding to the total flow deviation ΔQna is 0.75, and the NB grade is 0.25 based on the membership function of the antecedent part corresponding to. When the detected flow rate ratio Rde is larger than the target flow rate ratio Rsp and the deviation ΔR is ΔRpa shown in FIG. 5B, the antecedent corresponding to the total flow rate deviation ΔQ shown in FIG. Based on the membership function of the part, the grade of ZO corresponding to the deviation ΔRpa of the flow rate ratio is 0.25, and the grade of PB is 0.75.
[0070]
Based on the grade corresponding to the deviation ΔQna of the total flow rate and the grade corresponding to the deviation ΔRpa of the flow rate ratio, fuzzy variable grades corresponding to the antecedent parts of the first to ninth rules in the valve opening control rule are determined. Detection is performed for each rule as follows.
[0071]
The antecedent part of the first rule in the valve opening control rule is “IF ΔQ = ZO & ΔR = NB”, and the ZO grade corresponding to the total flow deviation ΔQna is 0.75, but the flow rate ratio There is no grade of NB corresponding to the deviation ΔRpa, and this first rule is ignored.
[0072]
The antecedent part of the second rule is “IF ΔQ = ZO & ΔR = PB”, the ZO grade corresponding to the total flow deviation ΔQna is 0.75, and the PB corresponding to the flow ratio deviation ΔRpa Since the grade is 0.75, the ZO grade 0.75 corresponding to the total flow deviation ΔQna and the PB grade 0.75 corresponding to the flow ratio deviation ΔRpa, whichever is smaller for minimum calculation. Is detected as a fuzzy variable grade corresponding to the second rule. In this case, the grade of the total flow rate deviation ΔQna and the grade of the flow rate deviation ΔRpa are equal, so that the grade 0.75 is the second rule. Is detected by the grade detector 31 as a fuzzy variable grade corresponding to.
[0073]
Since the consequent part of the second rule is “V1 = NS, V2 = PS”, it corresponds to the operation amount V1 of the valve opening degree of the first flow rate control means GM1 shown in FIG. The NS membership function is cleaved at the detected grade 0.75 position, and the area AB0C shown in FIG. 5C is obtained as the effective area. Also, in FIG. The PS membership function corresponding to the manipulated variable V2 of the valve opening degree of the second flow rate control means GM2 shown is truncated at the position of the detected grade 0.75, and a region abc0 shown in FIG. Is determined as the effective area.
[0074]
The antecedent part of the third rule is “IF ΔQ = NB & ΔR = ZO”, and the NB grade corresponding to the total flow deviation ΔQna is the grade 0.25 shown in FIG. Since the ZO grade corresponding to the deviation ΔRpa of the flow rate ratio is the grade 0.25 shown in FIG. 6B, the grade 0.25 is detected as the third rule grade by the minimum calculation as described above. Is done.
[0075]
Since the consequent part of the third rule is “V1 = NS, V2 = NS”, the manipulated variable V1 of the valve opening degree of the first flow rate control means GM1 based on the detected grade 0.25. The NS membership function corresponding to is cut off, the area of the region DE0C as shown in FIG. 6C is detected as an effective area, and the valve opening degree of the second flow rate control means GM2 is detected. The NS membership function corresponding to the manipulated variable V2 is truncated, and the area of the region de0f as shown in FIG. 6D is detected as an effective area.
[0076]
Further, the fourth, fifth, sixth and seventh rules are ignored because there is no grade corresponding to the total flow rate deviation ΔQna or the flow rate ratio deviation ΔRpa, as in the first rule.
[0077]
The antecedent part of the eighth rule is “IF ΔQ = NB & ΔR = PB”, and the NB grade corresponding to the total flow deviation ΔQna is the grade 0.25 shown in FIG. Since the grade of PB corresponding to the deviation ΔRpa of FIG. 7 is the grade 0.75 shown in FIG. 7B, as described above, the grade 0.25 is detected as the grade of the eighth rule by the minimum calculation, On the basis of the grade 0.25, the NB membership function corresponding to the manipulated variable V1 of the valve opening degree of the first flow rate control means GM1 corresponding to the consequent part of the eighth rule is cut off. 7 (c), the area of the region FGHI is detected as an effective area, and the PS membership function corresponding to the manipulated variable V2 of the valve opening of the second flow rate control means GM2 is truncated. In (d) of FIG. The area of the region ghc0 as shown is detected as the effective area.
[0078]
For the ninth rule, similarly to the above, grade 0.25 is detected according to the rule of the antecedent part, and based on the detected grade, the area of the region JKLH as shown in FIG. The effective area of the membership function of ZO corresponding to the valve opening manipulated variable V1 of the first flow control means GM1 is detected, and the area of the region ijkl as shown in FIG. 8D is the second flow control means. It is detected as the effective area of the membership function of ZO corresponding to the valve opening manipulated variable V2 of GM2.
[0079]
And the union of the effective areas of the membership functions respectively corresponding to the operation amounts V1, V2 of the first and second flow rate control means GM1, GM2 detected for each of the first to ninth rules as described above. Is calculated by the union detection unit 32. That is, for the valve opening operation amount V1 of the first flow control means GM1, the area ABEKLIFD as shown in FIG. 9C corresponds to the valve opening operation amount V1 of the first flow control means GM1. The area of the region abcdfg shown in (d) of FIG. 9 is obtained as the union of effective areas corresponding to the valve opening manipulated variable V2 of the second flow rate control means GM2.
[0080]
The union detector 32 detects the union of the effective areas of the membership functions corresponding to the manipulated variables V1 and V2 of the first and second flow control means GM1 and GM2 as described above. After In addition, information on the union of the effective areas is output to the valve opening operation amount detection unit 34.
[0081]
The valve opening manipulated variable detection unit 34 has a solution for obtaining the center of gravity of the union of the effective areas based on the union of the effective areas added from the union detection unit 32. Law Data is given in advance, and the valve opening manipulated variable detection unit 34 receives the sum information of the received effective area and the solution. Law Based on the data, the center of gravity Sv1 shown in FIG. 9C of the union of the effective areas corresponding to the valve opening operation amount V1 of the first flow rate control means GM1, and the second flow rate control means GM2 The center of gravity Sv2 shown in (d) of FIG. 9 of the union of the effective areas corresponding to the valve opening operation amount V2 is obtained. Note that the solution for obtaining the center of gravity of the union of the above effective areas Law There are various methods, and any of these methods may be used here. Law Description of data is omitted.
[0082]
The valve opening operation amount detector 34 detects the valve opening operation amount ΔV1 of the first flow control means GM1 and the valve opening operation amount ΔV2 of the second flow control means GM2 based on the obtained center of gravity. Then, the information of the obtained valve opening operation amounts ΔV1 and ΔV2 is output to the mixing control unit 33. The mixing control unit 33 supplies the voltages of the operation amounts ΔV1 and ΔV2 obtained by the valve opening operation amount detection unit 34 to the drive sources of the first and second flow rate control means GM1 and GM2, respectively. The valve opening degree of each flow control means GM1, GM2 is changed.
[0083]
According to this embodiment, the first flow rate control means GM1 for providing the bypass passage 15 and controlling the water flow rate of the bypass passage 15 with the valve opening degree and the hot water where the water flowing out of the bypass passage 15 joins. Since the second flow rate control means GM2 for controlling the flow rate Qyu on the side with the valve opening is provided, by variably controlling the valve openings of the first and second flow rate control means GM1, GM2, The flow rate ratio between the hot water side flow rate Qyu and the bypass flow rate Qbp can be variably controlled, and the total flow rate Q of the hot water side flow rate Qyu and the bypass flow rate Qbp can be controlled.
[0084]
In this embodiment, the flow rate ratio Rde between the bypass flow rate Qbp and the hot water side flow rate Qyu is detected while obtaining the target flow rate ratio Rsp between the hot water side flow rate Qyu and the bypass flow rate Qbp for supplying hot water at the hot water supply set temperature. According to the combination of the comparison result of comparing the detected flow rate ratio Rde with the target flow rate ratio Rsp, the comparison result of comparing the detected total flow rate Q with the set total flow rate Qsp, and the comparison results of the total flow rate and the flow rate ratio. Since the valve openings of the first and second flow rate control means GM1 and GM2 are controlled based on the determined valve opening degree control rules, the first and second flow rate control means GM1 and GM2 are considered in consideration of both the flow rate ratio and the total flow rate. The valve opening degree of each of the second flow rate control means GM1 and GM2 can be controlled, and of course during normal hot water supply operation, hot water supply from a state where after-boiling has occurred in the hot water supply heat exchanger 2 The hot water set temperature is also set at the time of re-draining. With an amount can be precisely and stably supplied.
[0085]
For example, when the valve openings of the first and second flow rate control means GM1 and GM2 are controlled in consideration of only the flow rate ratio so that hot water at a hot water supply set temperature can be supplied, Sometimes, as shown by the solid line in FIG. 11B, the hot water supply set temperature immediately after the start of the hot water, as compared with the hot water temperature fluctuation shown in the dotted line in FIG. 11B when the flow rate ratio control is not performed. In an area where the water pressure flowing into the water supply passage 3 is higher than the normal water pressure assumed in advance, the time of the discharge water flow rate after the start of the hot water shown in FIG. As shown in the change, immediately after the start of hot water, hot water is supplied at a flow rate higher than the set flow rate (set total flow rate). Conversely, in areas where the water pressure of the water supply source is lower than the normal water pressure, There is a possibility that hot water is supplied at a smaller flow rate.
[0086]
On the other hand, in this embodiment, as described above, the valve opening degree control of the first and second flow rate control means GM1 and GM2 is performed in consideration of both the flow rate ratio and the total flow rate. As shown in (a) and (b), at the time of re-heating, not only can the hot water at the hot water supply set temperature be instantaneously supplied after the start of hot water supply, but also the hot water flow rate does not fluctuate. An excellent effect that hot water can be supplied with a set flow rate can be obtained.
[0087]
In particular, in this embodiment, since the valve opening manipulated variables V1 and V2 of the first and second flow control means GM1 and GM2 are obtained by fuzzy logic operation, the detected flow rate ratio matches the target flow rate ratio. In addition, it is easy to make the total flow rate coincide with the set total flow rate, and hot water at the hot water supply set temperature can be supplied with the set total flow rate with higher accuracy.
[0088]
In addition, this invention is not limited to the said embodiment, It can take with various embodiment. For example, in the embodiment described above, the valve opening control of the first and second flow rate control means GM1 and GM2 is continuously performed while hot water is being supplied, but is performed only at the time of re-heating. It may be.
[0089]
Moreover, although the hot water heater having the system configuration as shown in FIG. 3 has been described as an example in the above embodiment, the present invention can be applied to hot water heaters other than FIG. For example, in FIG. 3, the second flow rate sensor FS <b> 2 that detects the total flow rate (tapping flow rate) Q is provided in the hot water supply passage 4 on the downstream side of the connection portion Z with the bypass passage 15. You may provide in the water supply path 3 upstream from the connection part W.
[0090]
Further, although the bypass passage 15 is not provided with a flow rate sensor, a bypass flow rate sensor for detecting the bypass flow rate Qbp may be provided in the bypass passage 15. When the bypass flow sensor is provided as described above, either one of the first flow sensor FS1 and the second flow sensor FS2 may be omitted. When a bypass flow rate sensor is provided and the first flow rate sensor FS1 is omitted, the bypass flow rate detection unit 22 detects the sensor output of the bypass flow rate sensor as a bypass flow rate Qbp, and the hot water side flow rate detection unit 21 The hot water side flow rate Qyu is obtained by subtracting the bypass flow rate Qbp detected by the bypass flow rate sensor from the total flow rate Q detected by the flow rate sensor FS2.
[0091]
When a bypass flow sensor for detecting the bypass flow Qbp is provided and the second flow sensor FS2 is omitted, the bypass flow detection unit 22 detects the sensor output of the bypass flow sensor as a bypass flow Qbp, The flow rate detection unit 26 detects the total flow rate Q as a combined flow rate of the hot water side flow rate Qyu detected by the first flow rate sensor FS1 and the bypass flow rate Qbp detected by the bypass flow rate sensor.
[0092]
Furthermore, only the second flow rate sensor FS2 for detecting the total flow rate Q may be provided without providing the first flow rate sensor FS1 and the bypass flow rate sensor. Based on the detected hot water temperature Tyu, the incoming water temperature Tin detected by the incoming water thermistor 5, the hot water supply temperature Tmix detected by the outgoing hot water thermistor 7, and the total flow rate Q detected by the second flow sensor FS2. Thus, by the calculation of the following equation (5), the bypass flow rate detection unit 22 obtains the bypass flow rate Qbp, and the hot water side flow rate detection unit 21 detects the obtained bypass flow rate Qbp by the second flow rate sensor FS2. Subtract from the total flow Q to obtain the hot water flow Qyu.
[0093]
Qbp = (Tyu−Tin) × Q / (Tmix−Tin) (5)
[0094]
Further, in the example of the water heater shown in FIG. 3, the second flow rate sensor FS2 for detecting the total flow rate Q is provided. However, the hot water side hot water temperature Tyu, the incoming water temperature Tin, the hot water side hot water and the bypass are provided. When the hot water temperature Tmix after mixing with the water in the passage 15 and the flow rate Qbp in the bypass passage 15 can be detected, the second flow rate sensor FS2 may be omitted. In this case, for example, the total flow rate Q can be calculated by the following equation (6).
[0095]
Q = (Tmix−Tin) × Qbp / (Tyu−Tin) (6)
[0096]
Further, in the water heater shown in FIG. 3, one always-on bypass passage 18 is provided, but this always-on bypass passage 18 may be omitted, or two or more always-on bypass passages 18 may be provided. .
[0097]
Further, a hot water heater having a bath function in the system configuration of the water heater shown in FIG. 3, for example, a hot water filling that connects the hot water supply passage 4 downstream of the connecting portion Z with the bypass passage 15 shown in FIG. A water heater with a hot water filling function for a bath in which a passage is provided and the hot water produced by the hot water heat exchanger 2 is dropped through the hot water passage, and for replenishing the bath water by circulating the bath water A water heater having a reheating function and a hot water filling function of a bath provided with a reheating circulation passage and a hot water filling passage for dropping hot water produced by the hot water supply heat exchanger 2 into the bathtub through the recirculation circulation passage. In addition, the present invention can be applied.
[0098]
Furthermore, in the above embodiment, the first upper limit change amount in the opening direction and the closing direction indicated in the valve opening degree control rule are equal, but the first upper limit change amount in the opening direction and the first upper limit change amount in the closing direction are May be set to different values. Similarly, the second upper limit change amount, the first lower limit change amount, and the second lower limit change amount may take different values in the opening direction and the closing direction.
[0099]
Furthermore, in the above embodiment, the flow rate ratio / total flow control unit 28 uses the fuzzy logic operation to control the valve openings of the first and second flow control means GM1 and GM2, but the fuzzy logic operation is performed. You may control the valve opening degree of each 1st and 2nd flow control means GM1, GM2 without using. For example, the first to ninth valve opening control rules as described above are given in advance, and the first and second flow rate control means are combined by combining the flow rate ratio deviation ΔR and the total flow rate deviation ΔQ. The valve opening operation amount detection data for obtaining the valve opening operation amount (change amount) of GM1 and GM2 is determined in advance, and the flow rate ratio / total flow control unit 28 compares the flow rate ratio comparison unit 24 with the total flow rate comparison. The variable direction of the valve opening degree of each of the first and second flow rate control means GM1, GM2 is obtained based on each comparison result of the unit 30 and the valve opening degree control rule, the deviation of the flow rate ratio and the total flow rate, and the above Based on the valve opening operation amount detection data, the amount of change in the valve opening of each of the first and second flow rate control means GM1, GM2 is obtained, and the first and second flow rate control means GM1, GM2 of The valve opening may be controlled.
[0100]
Further, the valve opening degree control rule according to the present invention is such that the detected flow rate ratio is equal to the target flow rate ratio, and the detected total flow rate is equal to the set total flow rate. What is necessary is just to be determined according to the combination of each comparison result of the flow rate ratio and the total flow rate in order to control the valve opening, and is not limited to the valve opening control rule shown in the above embodiment. . Furthermore, in the above embodiment, the membership function used for the fuzzy logic operation is triangular, but a bell-shaped membership function may be given.
[0101]
Furthermore, in the above embodiment, the grade detection unit 31 of the flow ratio / total flow control unit 28 is fuzzy by a minimum calculation that selects the smaller one of the grade of the flow ratio deviation ΔR and the total flow deviation ΔQ. The variable grade is selected and detected. For example, the fuzzy variable grade may be selected and detected by a maximum calculation that selects the larger one of the grade of the flow rate deviation ΔR and the total flow rate deviation ΔQ. The average of the grade of the deviation ΔR of the flow rate ratio and the grade of the deviation ΔQ of the total flow rate may be obtained, and the average value may be selected and detected as a fuzzy variable grade. Thus, by a method other than the minimum calculation, A fuzzy variable grade may be detected based on the grade of the flow rate deviation ΔR and the grade of the total flow deviation ΔQ.
[0102]
Furthermore, in the above embodiment, the union detection unit 32 of the flow ratio / total flow control unit 28 corresponds to, for example, the valve opening manipulated variable V1 of the first flow control means GM1 that matches the valve opening control rule. As the union of the effective areas of membership functions, the area ABEKLIFD as shown in FIG. 9C is obtained. For example, the area AB0C shown in FIG. 5C and the area AB0C in FIG. ), The area FGHI shown in FIG. 7C, and the area JKLH shown in FIG. 8C may be obtained as the union of the effective areas of the membership function. The same applies to the union of effective areas of membership functions corresponding to the valve opening manipulated variable V2 of the second flow rate control means GM2.
[0103]
【The invention's effect】
According to the present invention, the bypass flow path that bypasses the hot water supply heat exchanger and communicates between the water supply path and the hot water supply path is provided, and the flow rate of the hot water flowing out from the bypass path is controlled by the valve opening degree. Since the control means and the second flow rate control means for controlling the water flow rate of the bypass passage with the valve opening degree are provided, the valve opening degree of each of the first and second flow rate control means is controlled. It is possible to control both the flow rate ratio between the hot water flow rate and the bypass flow rate in the bypass passage, and the hot water flow rate and the total flow rate of the bypass flow rate.
[0104]
In this invention, furthermore, the target flow rate of the hot water side for supplying hot water at the hot water supply set temperature and the target flow rate of the bypass flow rate is obtained, the flow rate ratio is detected, and the detected flow rate ratio is compared with the target flow rate ratio, Further, the detected total flow rate is compared with the set total flow rate, the comparison result of the flow rate ratio and the total flow rate, and the valve opening degree control rule given in advance according to the combination of each comparison result of the flow rate ratio and the total flow rate, Based on the above, the valve opening degree of each of the first and second flow rate control means is controlled so that the detected flow rate ratio is matched with the target flow rate ratio, and the detected total flow rate is matched with the set total flow rate. Because it has a configuration with a controlled flow rate ratio / total flow rate control unit, it is possible to obtain an epoch-making effect that hot water at a set hot water temperature can be accurately supplied at a set total flow rate even when re-watering. Can do.
[0105]
In particular, the valve opening operation amounts of the first and second flow control means are detected by fuzzy logic operation, and the valve opening amounts of the first and second flow control means are determined according to the detected operation amounts. In the control configuration, it becomes possible to supply hot water at a hot water supply set temperature with a set total flow rate with higher accuracy.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a characteristic control configuration in this embodiment.
FIG. 2 is a block diagram showing a control configuration example of a flow rate ratio / total flow rate control unit that obtains valve opening manipulated variables of the first and second flow rate control means using fuzzy logic operations;
FIG. 3 is a model diagram showing a system configuration of a water heater shown in this embodiment.
FIG. 4 is a graph showing membership functions used in the fuzzy logic operation shown in the embodiment.
FIG. 5 is an explanatory diagram for illustrating a method for obtaining valve opening manipulated variables of the first and second flow rate control means GM1 and GM2 by fuzzy logic operation shown in the embodiment.
FIG. 6 is an explanatory diagram for illustrating a technique for obtaining valve opening manipulated variables of the first and second flow rate control means GM1 and GM2 by fuzzy logic operation shown in the embodiment.
FIG. 7 is an explanatory diagram for illustrating a method for obtaining valve opening manipulated variables of the first and second flow rate control means GM1 and GM2 by fuzzy logic operation shown in the embodiment.
FIG. 8 is an explanatory diagram for illustrating a technique for obtaining valve opening manipulated variables of the first and second flow rate control means GM1 and GM2 by fuzzy logic operation shown in this embodiment.
FIG. 9 is an explanatory diagram for illustrating a method for obtaining the valve opening manipulated variables of the first and second flow rate control means GM1 and GM2 by fuzzy logic operation shown in this embodiment.
FIG. 10 shows the flow rate of hot water and the temperature of hot water when the valve opening degree of each of the first and second flow rate control means GM1, GM2 is controlled by the method shown in this embodiment considering both the flow rate ratio and the total flow rate. It is a graph which shows each characteristic data.
FIG. 11 shows the characteristics of the hot water flow rate and the hot water supply temperature when the valve opening degree of each of the first and second flow rate control means GM1, GM2 is controlled by a method considering only the flow rate ratio of the flow rate ratio and the total flow rate. It is a graph which shows data.
FIG. 12 is a model diagram showing a system configuration of a conventional water heater.
[Explanation of symbols]
2 Hot water heat exchanger
3 water supply passage
4 Hot water passage
15 Bypass passage
23 Target flow ratio detector
24 Flow ratio comparison unit
25 Flow ratio detector
26 Total flow rate detector
27 Deviation detector
28 Flow Ratio / Total Flow Control Unit
30 Total flow rate comparison part
31 Grade detector
32 Union Set Detection Unit
34 Valve opening operation amount detector
GM1 first flow rate control means
GM2 Second flow rate control means
FS2 second flow sensor

Claims

給水通路から供給された水を加熱して湯を作り出し該湯を給湯通路に送出する給湯熱交換器と、上記給水通路と給湯通路間を上記給湯熱交換器を迂回して連通接続するバイパス通路と、該バイパス通路から流れ出た水が合流する湯側の流量を弁開度でもって制御する第１の流量制御手段と、上記バイパス通路を流れる水の流量を弁開度でもって制御する第２の流量制御手段と、上記バイパス通路の通水流量と湯側の流量との総流量を検出する総流量検出手段とを有し、バイパス通路から流れ出る水と湯側の湯とのミキシング後の湯温が予め定められた給湯設定温度になるためのバイパス通路の通水流量と湯側の流量との目標流量比を検出する目標流量比検出部と、バイパス通路の通水流量と湯側の流量との流量比を検出する流量比検出部とを備えた給湯器であって、上記流量比検出部により検出された流量比を上記目標流量比検出部により検出された目標流量比に比較する流量比比較部と；上記総流量検出手段により検出された総流量を予め定められた設定総流量に比較する総流量比較部と；上記流量比と総流量の各比較結果の組み合わせに応じて検出流量比を目標流量比に一致する方向に、かつ、検出総流量を設定総流量に一致する方向に前記第１と第２の各流量制御手段の弁開度を制御するための予め与えられている弁開度制御ルールと、上記流量比比較部と総流量比較部の各比較結果とに基づいて上記第１と第２の各流量制御手段の弁開度を前記弁開度制御ルールに従って制御して上記検出流量比が目標流量比に一致する方向に制御し併せて検出総流量が設定総流量に一致する方向に制御して給湯設定温度の湯を設定総流量でもって給湯するための流量比・総流量制御部と；が設けられていることを特徴とした給湯器。A hot water heat exchanger that heats water supplied from a water supply passage to produce hot water and sends the hot water to the hot water supply passage, and a bypass passage that connects the water supply passage and the hot water supply passage by bypassing the hot water heat exchanger And a first flow rate control means for controlling the flow rate on the hot water side where water flowing out from the bypass passage merges with the valve opening degree, and a second flow rate controlling the flow rate of water flowing through the bypass passage with the valve opening degree. Hot water after mixing of the water flowing out from the bypass passage and the hot water on the hot water side, and a total flow rate detecting means for detecting the total flow rate of the water flow rate in the bypass passage and the flow rate on the hot water side. A target flow rate detection unit for detecting a target flow rate ratio between the flow rate of the bypass passage and the flow rate of the hot water so that the temperature reaches a predetermined hot water supply set temperature, and the flow rate of the bypass passage and the flow rate of the hot water A flow ratio detector that detects the flow ratio A flow rate ratio comparison unit for comparing the flow rate ratio detected by the flow rate ratio detection unit with the target flow rate ratio detected by the target flow rate detection unit; detected by the total flow rate detection means A total flow rate comparison unit that compares the total flow rate with a predetermined set total flow rate; and detects the detected flow rate ratio in a direction that matches the target flow rate ratio according to the combination of the comparison results of the flow rate ratio and the total flow rate. A valve opening degree control rule given in advance for controlling the valve opening degree of each of the first and second flow rate control means in a direction that matches the total flow rate with the set total flow rate, the flow rate ratio comparison unit, Based on each comparison result of the flow rate comparison unit, the valve opening degree of each of the first and second flow rate control means is controlled according to the valve opening degree control rule so that the detected flow rate ratio matches the target flow rate ratio. Controlled and the detected total flow rate matches the set total flow rate. Water heater is characterized in that is provided; and the flow rate ratio-total flow rate control unit for the hot water supply with the setting the total flow rate of the hot water of the hot water supply set temperature by controlling the direction.

弁開度制御ルールは、上記検出総流量が設定総流量にほぼ等しく検出流量比が目標流量比よりも大きい場合に上記第１の流量制御手段の弁開度を予め定めた第１上限変化量を越えない範囲で開方向に小さく制御し、第２の流量制御手段の弁開度を予め定めた第２上限変化量を越えない範囲で閉方向に小さく制御する第１のルールと、検出総流量が設定総流量にほぼ等しく検出流量比が目標流量比よりも小さい場合に第１の流量制御手段の弁開度を小さく閉方向に、第２の流量制御手段の弁開度を小さく開方向にそれぞれ制御する第２のルールと、検出総流量が設定総流量よりも多くて検出流量比が目標流量比にほぼ等しい場合に第１の流量制御手段の弁開度を小さく閉方向に、第２の流量制御手段の弁開度を小さく閉方向にそれぞれ制御する第３のルールと、検出総流量が設定総流量よりも少なくて検出流量比が目標流量比にほぼ等しい場合に第１の流量制御手段の弁開度を小さく開方向に、第２の流量制御手段の弁開度を小さく開方向にそれぞれ制御する第４のルールと、検出総流量が設定総流量よりも少なくて検出流量比が目標流量比よりも大きい場合に第１の流量制御手段の弁開度を予め定めた第１下限変化量以上に開方向に大きく制御し、第２の流量制御手段の弁開度を閉方向に小さく制御する第５のルールと、検出総流量が設定総流量よりも少なくて検出流量比が目標流量比よりも小さい場合に第１の流量制御手段の弁開度を小さく閉方向に、第２の流量制御手段の弁開度を予め定めた第２下限変化量以上に開方向に大きく制御する第６のルールと、検出総流量が設定総流量よりも多くて検出流量比が目標流量比よりも大きい場合に第１の流量制御手段の弁開度を小さく開方向に、第２の流量制御手段の弁開度を大きく閉方向にそれぞれ制御する第７のルールと、検出総流量が設定総流量よりも多くて検出流量比が目標流量比よりも小さい場合に第１の流量制御手段の弁開度を大きく閉方向に、第２の流量制御手段の弁開度を小さく開方向にそれぞれ制御する第８のルールと、検出総流量が設定の総流量にほぼ等しく検出流量比が目標流量比にほぼ等しい場合には第１と第２の各流量制御手段の弁開度を変化させない第９のルールとから成ることを特徴とする請求項１記載の給湯器。The valve opening degree control rule is that a first upper limit change amount that predetermines the valve opening degree of the first flow rate control means when the detected total flow rate is substantially equal to the set total flow rate and the detected flow rate ratio is larger than the target flow rate ratio. A first rule that controls the valve opening of the second flow rate control means to be small in the closing direction within a range that does not exceed a predetermined second upper limit change amount, When the flow rate is substantially equal to the set total flow rate and the detected flow rate ratio is smaller than the target flow rate ratio, the valve opening degree of the first flow rate control means is reduced in the closing direction, and the valve opening degree of the second flow rate control means is reduced in the opening direction. And when the detected total flow rate is larger than the set total flow rate and the detected flow rate ratio is substantially equal to the target flow rate ratio, the valve opening degree of the first flow rate control means is decreased in the closing direction, The valve opening degree of the flow rate control means 2 is controlled to be small in the closing direction. When the detected total flow rate is less than the set total flow rate and the detected flow rate ratio is substantially equal to the target flow rate ratio, the valve opening degree of the first flow rate control unit is decreased and the second flow rate control unit is opened in the opening direction. A fourth rule for controlling the valve opening of each valve in a small opening direction, and opening the valve of the first flow rate control means when the detected total flow rate is smaller than the set total flow rate and the detected flow rate ratio is larger than the target flow rate ratio. A fifth rule for controlling the degree of opening in the opening direction to be greater than a predetermined first lower limit change amount and controlling the valve opening of the second flow rate control means to be small in the closing direction, and the detected total flow rate is greater than the set total flow rate When the detected flow rate ratio is smaller than the target flow rate ratio, the first lower flow rate control means is opened in the closing direction, and the second lower limit change amount is set in advance. The sixth rule for large control in the opening direction and the detected total flow rate When the detected flow rate ratio is larger than the target and the detected flow rate ratio is larger than the target flow rate ratio, the valve opening degree of the first flow rate control unit is controlled to be small and the valve opening degree of the second flow rate control unit is largely controlled to be closed. And when the detected total flow rate is larger than the set total flow rate and the detected flow rate ratio is smaller than the target flow rate ratio, the valve opening degree of the first flow rate control means is greatly increased in the closing direction, and the second flow rate is set. An eighth rule for controlling the valve opening of the control means in a small opening direction, and when the detected total flow rate is approximately equal to the set total flow rate and the detected flow rate ratio is approximately equal to the target flow rate ratio, the first and second rules The hot water heater according to claim 1, comprising a ninth rule that does not change the valve opening degree of each flow rate control means.

目標流量比に対する検出流量比の偏差と、設定総流量に対する検出総流量の偏差とを求める偏差検出部が設けられ、上記流量比と総流量の各偏差の組み合わせを前件部とし、その偏差の組み合わせに応じた第１と第２の各流量制御手段の弁開度制御形態を後件部とした弁開度制御ルールと、上記偏差検出部により求められた流量比の偏差と総流量の偏差とに基づいたファジィ論理演算により、流量比・総流量制御部は、第１と第２の各流量制御手段の弁開度の操作量を求め、この求めた操作量に応じて第１と第２の各流量制御手段の弁開度を制御する構成としたことを特徴とする請求項１又は請求項２記載の給湯器。A deviation detector is provided to calculate the deviation of the detected flow rate relative to the target flow rate ratio and the detected total flow rate relative to the set total flow rate. The valve opening degree control rule having the valve opening degree control form of each of the first and second flow rate control means corresponding to the combination as a consequent part, the deviation of the flow rate ratio obtained by the deviation detecting part and the deviation of the total flow rate By the fuzzy logic operation based on the above, the flow rate ratio / total flow rate control unit obtains the operation amount of the valve opening of each of the first and second flow rate control means, and the first and second flow rate control means according to the obtained operation amount. 3. The water heater according to claim 1, wherein the valve opening degree of each of the flow rate control means is controlled.

弁開度制御ルールの前件部は、目標流量比に対する検出流量比の偏差の大小に応じた複数のメンバーシップ関数と、設定総流量に対する検出総流量の偏差の大小に応じた複数のメンバーシップ関数とから成り、弁開度制御ルールの後件部は、第１の流量制御手段の弁開度操作量の大小に応じた複数のメンバーシップ関数と、第２の流量制御手段の弁開度操作量の大小に応じた複数のメンバーシップ関数とから成り、偏差検出部により求められた流量比と総流量の各偏差に基づき、上記前件部のメンバーシップ関数からファジィ変数グレードを検出するグレード検出部と、検出されたファジィ変数グレードに基づいて前記弁開度制御ルールに合致した第１の流量制御手段に対応した上記後件部のメンバーシップ関数の有効面積の和集合と第２の流量制御手段に対応した後件部のメンバーシップ関数の有効面積の和集合とをそれぞれ検出する和集合検出部と、これら検出された第１と第２の各流量制御手段に対応した有効面積の和集合の重心をそれぞれ算出し、該求めた重心に基づき第１と第２の各流量制御手段の弁開度の操作量をそれぞれ検出する弁開度操作量検出部とが設けられていることを特徴とした請求項３記載の給湯器。The antecedent part of the valve opening control rule consists of multiple membership functions according to the magnitude of the deviation of the detected flow ratio relative to the target flow ratio, and multiple memberships according to the magnitude of the deviation of the detected total flow relative to the set total flow And the consequent part of the valve opening control rule includes a plurality of membership functions corresponding to the magnitude of the valve opening manipulated variable of the first flow control means and the valve opening of the second flow control means A grade that detects fuzzy variable grades from the membership function of the antecedent part above, based on the flow rate ratio obtained by the deviation detector and each deviation of the total flow rate. And a sum of effective areas of membership functions of the consequent part corresponding to the first flow rate control means that matches the valve opening degree control rule based on the detected fuzzy variable grade; A union detecting unit for detecting each union of effective areas of the membership function of the consequent part corresponding to the volume control means, and an effective area corresponding to each of the detected first and second flow control means. There is provided a valve opening operation amount detection unit that calculates the center of gravity of each union and detects the operation amount of the valve opening of each of the first and second flow rate control means based on the obtained center of gravity. The hot water heater according to claim 3, wherein