JP3777035B2

JP3777035B2 - Gas combustion equipment

Info

Publication number: JP3777035B2
Application number: JP34205997A
Authority: JP
Inventors: 達也和田
Original assignee: 株式会社ガスター
Priority date: 1997-11-27
Filing date: 1997-11-27
Publication date: 2006-05-24
Anticipated expiration: 2017-11-27
Also published as: JPH11159749A

Description

【０００１】
【発明の属する技術分野】
この発明は、選択的に燃焼が行われる複数の領域を有する燃焼部を備えたガス燃焼装置に関する。
【０００２】
【従来の技術】
ガス燃焼装置例えばガス給湯装置は、燃焼部と、燃焼部からの燃焼熱を受ける熱交換部と、この熱交換部を通る給湯回路と、燃焼部にガスを供給するガス供給手段と、燃焼部に燃焼用空気を供給する送風手段と、ガス供給手段と送風手段を制御する制御手段とを備えている。
制御手段は、給湯回路を流れる水量等に応じて燃焼部へのガス供給を制御して総燃焼熱量を変え、給湯回路から出湯される湯の温度を設定温度に一致させるようにしている。具体的には、ガス供給手段の比例弁を制御して、燃焼部への供給ガス圧を制御する。
【０００３】
ところで、ガス給湯装置には、燃焼部を燃焼面積が異なる複数の領域に分割して選択的燃焼を行えるようにしたものがある。すなわち、面積の小さな領域で燃焼を行っている状態で、出湯量の増大等により要求燃焼熱量が増大して比例弁電流が上限値近傍に達した時には、面積の大きな領域での燃焼に切り換える。これとは逆に、面積の大きな領域で燃焼を行っている状態で、出湯量の減少等により要求燃焼熱量が減少して比例弁電流が下限値近傍に達した時には、面積の小さな領域での燃焼に切り換える。
【０００４】
上記のように隣接する一方の領域から他方の領域へと燃焼領域を切り換える際には、過渡的制御を実行する。すなわち、一方の領域へのガス供給を継続してその領域の火炎を維持した状態で、他方の領域へのガス供給を行って火移りを生じせしめ、それから一方の領域へのガス供給を停止する。この火移りに際して、従来では、出湯温度を設定温度に維持するために総燃焼熱量の変動を抑えるようにしている。すなわち、一方の領域での燃焼に比べて両方の領域での燃焼では、燃焼面積が増大するため、この燃焼面積の増大に反比例して比例弁電流を下げて供給ガス圧を下げ、総燃焼熱量の変動を抑制しているのである。
【０００５】
【発明が解決しようとする課題】
上記のように、一方の領域での燃焼から両方の領域での燃焼に移行して火移りを行う際に供給ガス圧を一時的に下げると、次のような不都合がある。
制御手段は、図４に示すようにファン（制御手段）の回転数，すなわち送風量（送風圧）を、上記比例弁電流値すなわち供給ガス圧と比例関係にあるように制御し、常に最適空燃比で燃焼を行うようにしている。しかし、制御手段からの制御に対するファン（送風手段）の応答遅れがあるため、ファン回転数（送風量）が比例弁電流値（供給ガス圧）の急激な変動に追随できない。すなわち、上記火移りに際して、供給ガス圧の急激な低下が生じた時に、送風量はそれ以前の供給ガス圧に対応して多いままになっている。その結果、上記一方の領域での火炎が不安定になるばかりか、上記他方の領域の炎口から噴出するガスには過剰の燃焼空気が含まれてしまうため、火移りの条件が悪化する。そのため、一方の領域から他方の領域に火が移らないまま、一方の領域へのガス供給が停止し、燃焼が中断してしまうことがある。
【０００６】
【課題を解決するための手段】
請求項１の発明は、（イ）複数の領域を有する燃焼部と、（ロ）上記燃焼部にガスを供給するガス供給手段と、（ハ）上記燃焼部に燃焼用空気を供給する送風手段と、（ニ）上記ガス供給手段を制御して燃焼部の複数の領域への選択的ガス供給と供給ガス圧を制御するとともに、送風手段を制御して上記供給ガス圧に対応する風量の燃焼用空気を燃焼部に供給する制御手段と、を備えた給湯装置において、上記制御手段は、上記燃焼部における隣接する一方の領域から他方の領域へと燃焼領域を切り換える際に過渡的制御を実行し、この過渡的制御では、上記ガス供給手段から燃焼部への供給ガス圧を大きく変更することなく当該一方の領域へのガス供給を維持したまま当該他方の領域へもガス供給を行うことにより、当該一方の領域から当該他方の領域への火移りを生じせしめ、その後で、当該一方の領域へのガス供給を停止することを特徴とする。
【０００７】
請求項２の発明は、請求項１に記載のガス燃焼装置において、上記制御手段は、要求される総燃焼熱量の増大に伴い、燃焼熱量の小さな一方の領域での燃焼から、燃焼熱量の大きな隣接する他方の領域での燃焼に切り換えるための過渡的制御を実行し、この過渡的制御において、予め供給ガス圧を所定圧に減じ、それから上記一方の領域へのガス供給を維持したまま上記他方の領域へのガス供給を行うことにより、火移りを生じせしめることを特徴とする。
請求項３の発明は、請求項１または２に記載のガス燃焼装置において、上記制御手段は、要求される総燃焼熱量の増大に伴い、燃焼熱量の小さな一方の領域での燃焼から、燃焼熱量の大きな隣接する他方の領域での燃焼に切り換えるための過渡的制御を実行し、この過渡的制御において、隣接する２つの領域での燃焼状態から、上記一方の領域へのガス供給を停止する際に、供給ガス圧を減じることを特徴とする。
請求項４の発明は、請求項１に記載のガス燃焼装置において、上記制御手段は、要求される総燃焼熱量の減少に伴い、燃焼熱量の大きな一方の領域での燃焼から、燃焼熱量の小さな隣接する他方の領域での燃焼に切り換えるための過渡的制御を実行し、この過渡的制御において、予め供給ガス圧を所定圧に増大させ、それから上記一方の領域へのガス供給を維持したまま上記他方の領域へのガス供給を行うことにより、火移りを生じせしめることを特徴とする。
請求項５の発明は、請求項１または４に記載のガス燃焼装置において、上記制御手段は、要求される総燃焼熱量の減少に伴い、燃焼熱量の大きな一方の領域での燃焼から、燃焼熱量の小さな隣接する他方の領域での燃焼に切り換えるための過渡的制御を実行し、この過渡的制御において、隣接する２つの領域での燃焼状態から、上記一方の領域へのガス供給を停止する際に、供給ガス圧を増大させることを特徴とする。
【０００８】
請求項６の発明は、請求項１〜５のいずれかに記載のガス燃焼装置において、上記制御手段は、上記過渡的制御において、上記隣接する２つの領域へのガス供給を所定時間行っている際に、供給ガス圧を減じることを特徴とする。
請求項７の発明は、請求項１〜６のいずれかに記載のガス燃焼装置において、上記制御手段は、上記過渡的制御において、上記一方の領域へのガス供給を維持したまま上記他方の領域へもガス供給を行う際に、その前後の燃焼部での総燃焼熱量の変動率に比べて、供給ガス圧の変動率を小さくすることを特徴とする。
請求項８の発明は、請求項７に記載のガス燃焼装置において、上記制御手段は、上記過渡的制御において、上記一方の領域へのガス供給を維持したまま上記他方の領域へもガス供給を行う際に、供給ガス圧をほぼ等しく維持することを特徴とする。
請求項９の発明は、請求項８に記載のガス燃焼装置において、上記ガス供給手段は、上記燃焼部の各領域に対峙する互いに独立した領域を有するガス噴射部材と、上流側に比例弁を有し下流側が上記ガス噴射部材の複数の領域にそれぞれ副開閉弁を介して連なるガス通路とを備え、上記制御手段は、上記副開閉弁を制御することにより燃焼部の燃焼領域を選択し、比例弁への供給電流を制御することにより上記供給ガス圧を制御し、しかも上記制御手段は、上記過渡的制御において、上記一方の領域へのガス供給を維持したまま上記他方の領域へもガス供給を行う際に、その前後において上記ガス噴射部材からの供給ガス圧が等しくなるように、比例弁への供給電流を所定量増大させることを特徴とする。
請求項１０の発明は、請求項１〜９のいずれかに記載のガス燃焼装置において、さらに、上記燃焼部からの燃焼熱を受ける熱交換部と、この熱交換部を通る給湯回路と、上記制御手段に設定温度情報を出力する温度設定手段とを備え、上記制御手段は、上記給湯回路から出湯される湯の温度が設定温度となるように上記ガス供給手段を制御することを特徴とする。
【０００９】
【発明の実施の形態】
以下、この発明の一実施形態をなすガス給湯装置（ガス燃焼装置）について、図面を参照しながら説明する。図２に示すように、この給湯装置は、ケーシング１の下部と上部に収容された燃焼部２および熱交換部３と、ケーシング１の底部に連結されたファン４（送風手段）とを備えている。このケーシング１には、燃焼部２の上流側と下流側を接続するバイパス路５が設けられており、このバイパス路５には、風量センサ６が設けられている。
【００１０】
上記燃焼部２は、図中左右に分かれて配置された２つの領域２ａ，２ｂ（第１，第２領域）を有している。領域２ａの面積は領域２ｂより小さく、供給ガス圧が一定であると仮定すると、領域２ａでの燃焼熱量は領域２ｂより小さい。
各領域２ａ，２ｂでは、偏平な濃バーナエレメントと淡バーナエレメントが図中左右方向に交互に並んで配置されている。なお、各領域２ａ，２ｂの両端は、濃バーナエレメントが配置されており、したがって、領域２ａ，２ｂの境では、濃バーナエレメントが並んでいることになる。
なお、濃バーナエレメントは、最適空燃比を基準にすると燃焼空気量に対してガス量が多くなるように、燃焼空気の導入口が狭くなっており、淡バーナエレメントは、燃焼空気量に対してガス量が少なくなるように、燃焼空気の導入口が広くなっている。淡バーナエレメントでは、その上面に形成された炎口からの火炎が高く、濃バーナエレメントでは、火炎が低く、淡バーナエレメントからの火炎にガス燃料を補充する役割を担う。
【００１１】
燃焼部２にガスを供給する手段１０は、ノズルブロック１１（ガス噴射部材）と、このノズルブロック１１に接続されるガス通路１２と、このガス通路１２の上流側に設けられた主開閉弁１３および比例弁１４（電磁圧力比例制御弁）と、ガス通路１２の下流側に設けられた２つの副開閉弁１５ａ，１５ｂとを備えている。ノズルブロック１１は２つの領域１１ａ，１１ｂに仕切られており、この領域１１ａ，１１ｂは、上記副開閉弁１５ａ，１５ｂを介して、ガス通路１１に連なっている。ノズルブロック１１の各領域１１ａ，１１ｂは、燃焼部２の領域２ａ，２ｂに対峙しており、各バーナエレメントの導入口に対峙するノズル部を有している。
【００１２】
上記熱交換部３には、給湯回路２０が通っている。この給湯回路２０は、熱交換部３を通る受熱管２１と、この受熱管２１の入口端に接続された給水管２２（上流側，給水側）と、受熱管２１の出口端に接続された給湯管２３（下流側，給湯側）と、受熱管２１と並列をなして給水管２２と給湯管２３との間に接続されたバイパス管２４とを有している。給湯管２３の下流端には給湯栓２５が設けられている。
給水管２２には、入水温度を検出する温度センサ２６と、給湯回路２０を流れる流量（出湯量）を検出するフローセンサ２７が設けられている。給湯管２３には出湯温度を検出するための温度センサ２８と、ギアモータ駆動式の流量制御弁２９が設けられている。
【００１３】
ガス給湯装置は、さらにマイクロコンピュータを含む制御ユニット３０（制御手段）と、この制御ユニット３０に設定温度情報を出力するリモートコントローラ３５（温度設定手段）とを備えている。
【００１４】
上記制御ユニット３０は、風量センサ６，温度センサ２６，２８，フローセンサ２９からの検出信号やリモートコントローラ３５からの設定温度情報に基づいて、図示しない点火機構やガス供給系の弁１３，１４，１５ａ，１５ｂを制御し（ガス供給制御，燃焼制御）、ファン４を制御し（風量制御）、流量制御弁２９を制御する（出湯量制御）。
【００１５】
次に、図３に基づいて、ガス供給制御の概略を説明する。
上記給湯栓２５の開によりフローセンサ２７で水流を検出した時に、制御ユニット３０は、これに応答して点火動作を行うとともに主開閉弁１３を開き、一方の副開閉弁１５ａを開く。すると、ガス通路１２からのガスがノズルブロック１１の一方の領域１１ａから燃焼部２の一方の領域２ａに供給され、この領域２ａでの燃焼が行われる。そして、フローセンサ２７で検出される水量と、温度センサ２６で検出される入水温度と、リモートコントローラ３５からの設定温度に基づいて、フィードフォワード制御成分を演算し、温度センサ２８で検出された出湯温度と上記設定温度に基づいてフィードバック制御成分を演算する。そして、フィードフォワード制御成分とフィードバック制御成分を加算した制御値に基づいて比例弁１４への供給電流を制御することにより、ノズルブロック１１の領域１１ａからの供給ガス圧を制御し、ひいては供給ガス圧と比例する燃焼部２の領域２ａでの燃焼熱量を制御し、給湯栓２５から出湯される湯の温度を設定温度に一致させる。このようなフィードフォワード制御，フィードバック制御に基づく制御を、以下の説明において通常燃焼制御と称する。
【００１６】
なお、上記比例弁１４の出口圧力は、供給電流と比例関係にある。ノズルブロック１１のノズル部での供給ガス圧は、比例弁１４の出口圧力とほぼ等しいが、厳密には、比例弁１４の出口圧力から、比例弁１４からノズル部までの経路での圧力損失を差し引いた圧力である。
【００１７】
前述したように、要求燃焼熱量が小さい場合には、主開閉弁１３と副開閉弁１５ａのみ開き、副開閉弁１５ｂは閉じたままにしておくので、一方の領域２ａでの燃焼が行われる。この燃焼状態をＡ面燃焼と称する。
上記Ａ面燃焼において、要求燃焼熱量が増大した場合には、これに応じて比例弁１４への供給電流を増大させることにより、供給ガス圧を増大させ、ひいては燃焼部２ａでの総燃焼熱量を増大させる。図３に示すように、比例弁１４への供給電流が増大して電流値が（Ｘ１）に達し、総燃焼熱量が（Ｙ１）に達した時には、燃焼領域の切り換えを行う。概略的には、副開閉弁１５ａを閉じて副開閉弁１５ｂを開き、小面積の領域２ａでの燃焼から大面積の領域２ｂでの燃焼（以下、Ｂ面燃焼と称す）に切り換える。なお、この切り換えの際には、実際には複雑な過渡的制御を行うが、この過渡的制御は本発明の特徴部をなすものであるので、後で詳細に説明する。
【００１８】
上記Ｂ面燃焼への切り換えが終了し上記通常燃焼制御に戻って安定した時点では、Ｂ面燃焼での総燃焼熱量（Ｙ２）がＡ面燃焼での総燃焼熱量（Ｙ１）とほぼ変わらないように、比例弁１４への供給電流値が減じられる。すなわち、燃焼面積の増大に反比例して比例弁１４への供給電流値が減じられる。この時の供給電流値を図３において（Ｘ２）で表す。
【００１９】
上記Ｂ面燃焼における通常燃焼制御において要求燃焼熱量が増大した場合には、これに応じて比例弁１４への供給電流を増大させることにより、供給ガス圧を増大させ、ひいては総燃焼熱量を増大させる。そして、比例弁１４への供給電流が増大して電流値（Ｘ３）に達し、総燃焼熱量が（Ｙ３）に達した時には、燃焼領域の切り換えを行う。すなわち、副開閉弁１５ａをも開いて２つの領域２ａ，２ｂでの燃焼（以下、Ａ＋Ｂ面燃焼と称す）に切り換える。この切り換えに応じて、Ａ＋Ｂ面燃焼での総燃焼熱量（Ｙ４）がＢ面燃焼での総燃焼熱量（Ｙ３）とほぼ変わらないように、比例弁１４への供給電流値が減じられる。この時の供給電流値を図３において（Ｘ４）で表す。
上記Ａ＋Ｂ面燃焼において、比例弁１４への電流値を最大限にしても、出湯温度を設定温度にできない場合には、流量制御弁２９の開度を絞り、出湯量を減少させることにより、出湯温度と設定温度の一致を確保する。
【００２０】
上記とは逆に、Ａ＋Ｂ面燃焼において要求燃焼熱量の減少に応じて比例弁１４への供給電流が低下して（Ｘ５）に達した時には、Ｂ面燃焼に切り換える。このＢ面燃焼の燃焼熱量（Ｙ６）は、Ａ＋Ｂ面燃焼での燃焼熱量（Ｙ５）とほぼ等しく、比例弁１４への供給電流は、Ａ＋Ｂ面燃焼での電流値（Ｘ５）から、Ｂ面燃焼での電流値（Ｘ６）へと燃焼面積の減少に反比例して増大される。なお、この切り換え時点での総燃焼熱量（Ｙ５），（Ｙ６）は、前述したＢ面燃焼からＡ＋Ｂ面燃焼への切り換え時点での総燃焼熱量（Ｙ３），（Ｙ４）より小さく、切り換え制御にヒステリシス特性を持たせている。
【００２１】
さらに、Ｂ面燃焼において要求燃焼熱量の減少に応じて比例弁１４への供給電流が低下して（Ｘ７）に達した時には、Ａ面燃焼に切り換える。このＡ面燃焼での燃焼熱量（Ｙ８）とＢ面燃焼での燃焼熱量（Ｙ７）はほぼ等しく、比例弁１４への供給電流は、Ｂ面燃焼での電流値（Ｘ７）から、Ａ面燃焼での電流値（Ｘ８）へと増大する。なお、この切り換え時点での燃焼熱量（Ｙ７），（Ｙ８）は、前述したＡ面燃焼からＢ面燃焼への切り換え時点での燃焼熱量（Ｙ１），（Ｙ２）より小さく、切り換え制御にヒステリシス特性を持たせている。
上記Ｂ面燃焼からＡ面燃焼への切り換えの際には、実際には複雑な過渡的制御を行うが、この過渡的制御も本発明の特徴部をなすものであり、後で詳細に説明する。
【００２２】
上記制御ユニット３０は、上記ガス供給制御と同時にファン４の制御を行う。すなわち、上記供給ガス圧に見合う風量が得られるように、すなわち最適空燃比が得られるように、ファン４を制御する。この際、風量センサ６での検出風量を監視し、この検出風量が供給ガス圧と見合うようにファン４を制御する。
【００２３】
次に、本発明の特徴部をなす、Ａ面燃焼からＢ面燃焼への切り換え時点、およびＢ面燃焼からＡ面燃焼への切り換え時点での過渡的制御について説明する。このような燃焼領域の切り換えでは、燃焼している領域が燃焼停止となり、燃焼停止状態の領域が燃焼状態となるので、火移りを確実に行うための過渡的制御が求められるのである。なお、この過渡的制御では、前述した通常燃焼制御と違って、検出情報や設定温度情報を用いることはない。
【００２４】
まず、Ａ面燃焼からＢ面燃焼への切り換えについて説明する。図１（Ａ）に示すように、まず、Ａ面燃焼における比例弁１４への供給電流を前述した（Ｘ１）から所定値（Ｘ１１）まで減少させる（比例弁１４の開度をほぼ半開にする）。次に、副開閉弁１５ａが開いた状態で副開閉弁１５ｂを開くことにより、燃焼部２の領域２ａのみならず領域２ｂにもガスを供給し、Ａ面燃焼から一旦Ａ＋Ｂ面燃焼に移行させる。すなわち、火移りを実行する。
上記Ａ面燃焼からＡ＋Ｂ面燃焼への移行の際に、比例弁１４への供給電流を大きく変えず、ノズルブロック１１からの供給ガス圧の変動を抑える。
【００２５】
制御ユニット３０は、上記ガス供給制御と同時に、ファン４を制御して送風量を供給ガス圧に対応させて調節し、最適空燃比が得られるようにしている。この送風量は、比例弁１４への供給電流をＡ面燃焼での前述した（Ｘ１）から所定値（Ｘ１１）まで減少させる過程では、これに追随して減少する。これにより、燃焼領域２ａでの火炎は安定した状態を保ちつつ、その高さを減じる。
そして、上記領域２ａへのガス供給状態（Ａ面燃焼状態）から、２つの領域２ａ，２ｂへのガス供給状態に移行する際には、上述したように供給ガス圧の変動が抑えられているため、送風量を大きく変動させなくて済み、その応答遅れによって領域２ａでの火炎が不安定になったり、領域２ｂのガスが過剰に燃焼空気を含むようなこともなくなる。このように、領域２ａでの火炎の安定と、領域２ｂの炎口での最適空燃比に近いガスの噴出によって、火移りを確実に行うことができる。
【００２６】
なお、本実施形態では、上記移行の前後におけるノズルブロック１１からの供給ガス圧の変動を実質的にゼロにする（移行の前後での供給ガス圧を実質的に等しくする）工夫をしている。すなわち、比例弁１４への供給電流を変えず、その出口圧力を変えない状態で、副開閉弁１５ａのみならず副開閉弁１５ｂを開くと、ガス流量が増え、それに伴い比例弁１４からノズルブロック１１のノズル部までの圧力損失が増大し、このノズル部での供給ガス圧が若干量低下する。そこで、この圧力損失の増大分を補うべく、本実施形態では、供給電流値を（Ｘ１１）から（Ｘ１２）まで若干量大きくし、比例弁１４の出口圧力を大きくしている。その結果、副開閉弁１５ｂを開いた時でも、ノズルブロック１１からの供給ガス圧の変動をゼロにすることができるのである。このようにして、火炎の安定を極力維持することができ、火移りをより一層確実なものとすることができるのである。
【００２７】
また、本実施形態では、上述したように副開閉弁１５ｂの開き動作に先立って、比例弁１４への供給電流を（Ｘ１）から（Ｘ１１）に落とし、総燃焼熱量を（Ｙ１）から（Ｙ１１）に落としているので、上記副開閉弁１５ｂの開き動作によるＡ＋Ｂ面燃焼での移行時に、燃焼熱量（Ｙ１２）は著しく増大せず、火移り時に発生する音を小さく抑えることができるとともに、出湯温度の瞬間的な上昇をも抑えることができる。
【００２８】
上記のように比例弁１４への供給電流を（Ｘ１２）にすると同時に副開閉弁１５ｂを開いた後、火移りのために確保している所定時間経過する過程で、供給電流を（Ｘ１３）に減じ，燃焼熱量を（Ｙ１３）まで減じる。これは、Ａ＋Ｂ面燃焼の総燃焼熱量が要求燃焼熱量より多いため、少しでも燃焼熱量を下げることにより、出湯温度の上昇を抑えるためである。
【００２９】
上記のように、比較的短い時間Ａ＋Ｂ面燃焼を実行した後で、副開閉弁１５ａを閉じることにより、Ｂ面燃焼に移行する。この移行の過程でも火炎の安定を図る観点からは供給ガス圧を大きく変動させないようにするのが好ましい。とは言え、上記火移りを実行した後であるので、それほど厳格に考慮する必要はない。本実施形態では、比例弁１４への供給電流を（Ｘ１３）から（Ｘ１４）へと減じて燃焼熱量を（Ｙ１３）から（Ｙ１４）へと減じ、その後の通常燃焼制御への移行で、供給電流（Ｘ２），燃焼熱量（Ｙ２）に達するのを早くしている。なお、図１（Ａ）において、点線で示す制御が、過渡的制御に相当するものである。図３では、この過渡的制御を省略して、座標（Ｘ１，Ｙ１）から（Ｘ２，Ｙ２）への矢印で示している。
【００３０】
次に、Ｂ面燃焼からＡ面燃焼への切り換えについて説明する。図１（Ｂ）に示すように、まず、比例弁１４への供給電流をＢ面燃焼での前述した（Ｘ７）から所定値（Ｘ１５）まで増大させ、比例弁１４の開度をほぼ半開にする。次に、副開閉弁１５ｂが開いた状態で副開閉弁１５ａを開くことにより、燃焼部２の領域２ｂのみならず領域２ａにもガスを供給し、Ｂ面燃焼から一旦Ａ＋Ｂ面燃焼に移行させる。すなわち、火移りを実行する。
上記Ｂ面燃焼からＡ＋Ｂ面燃焼への移行時点でも、比例弁１４への供給電流を大きく変えず、ノズルブロック１１からの供給ガス圧の変動を抑える。
【００３１】
送風量は、比例弁１４への供給電流をＢ面燃焼での前述した（Ｘ７）から所定値（Ｘ１５）まで増大させる過程では、これに追随して増大する。これにより、燃焼領域２ａでの火炎は安定した状態を保ちつつ、その高さを増大させる。そして、上記領域２ｂへのガス供給状態すなわちＢ面燃焼状態から、２つの領域２ａ，２ｂへのガス供給状態に移行する際に、上記供給ガス圧の変動が抑えられているため、送風量を大きく変動させずに済み、この送風量の応答遅れによる不都合を排除でき、火移りを確実に行うことができる。
【００３２】
上記Ｂ面燃焼からＡ＋Ｂ面燃焼への移行においても、供給電流値を（Ｘ１５）から（Ｘ１６）まで若干量大きくし、比例弁１４の出口圧力を大きくして、比例弁１４の出口からノズルブロック１１のノズル部までの圧力損失の増大分を補償している。その結果、副開閉弁１５ａを開いた時でも、ノズルブロック１１からの供給ガス圧の変動をゼロにすることができ、火炎の安定を極力維持して、火移りをより一層確実なものとすることができる。
【００３３】
なお、本実施形態では、上述したように副開閉弁１５ａの開き動作に先立って、比例弁１４への供給電流をＸ７からＸ１５（燃焼熱量Ｙ１５）へと増大させているので、火炎を高くすることができ、火移りをより一層確実なものとすることができる。
【００３４】
上記のように比例弁１４への供給電流を（Ｘ１６）にすると同時に副開閉弁１５ａを開いた後、火移りのために確保している所定時間経過する過程で、供給電流を（Ｘ１７）まで減じ，燃焼熱量を（Ｙ１７）まで減じる。Ａ＋Ｂ面燃焼での総燃焼熱量が要求燃焼熱量より多いため、少しでも燃焼熱量を下げることにより、出湯温度の上昇を抑えるためである。
【００３５】
上記のように、比較的短い時間Ａ＋Ｂ面燃焼を実行した後で、副開閉弁１５ｂを閉じることにより、Ａ面燃焼に移行する。この移行の過程で、比例弁１４への供給電流を（Ｘ１７）から（Ｘ１８）へと増大させて燃焼熱量を（Ｙ１７）から（Ｙ１８）へと増大させ、その後の通常燃焼制御への移行で、供給電流（Ｘ８），燃焼熱量（Ｙ８）に達するのを早くする。なお、図１（Ｂ）において、点線で示す制御が、過渡的制御に相当するものである。図３では、この過渡的制御を省略して、座標（Ｘ７，Ｙ７）から（Ｘ８，Ｙ８）への矢印で示しているのである。
【００３６】
本実施形態では、領域２ａ，領域２ｂの境界において濃バーナエレメントが隣接しているため、比較的火移りがしにくいが、上記過渡的制御の工夫により、このような構成でも確実に火移りさせることができる。
【００３７】
なお、この発明は、上記の実施形態に限定されるものでなく、適宜設計変更可能である。
例えば、上記過渡的制御において、Ａ面燃焼からＡ＋Ｂ面燃焼への移行時またはＢ面燃焼からＡ＋Ｂ面燃焼への移行時に、比例弁１４への供給電流を変えなくてもよい。この場合、圧力損失の増大分だけノズルブロック１１のノズル部での供給ガス圧が若干量低減するが、供給ガス圧はほぼ等しいと言うことができ、火移りを確実に行うことができる。
【００３８】
従来では、燃焼面切り換えに伴う過渡的制御において、Ａ面燃焼からＡ＋Ｂ面燃焼への移行時またはＢ面燃焼からＡ＋Ｂ面燃焼への移行時に、供給ガス圧を大きく変えて燃焼熱量の変動をほぼゼロにしている。このような従来例と本発明を比較すれば、本発明の制御の特徴は、次のように表すことができる。すなわち、本発明の制御では、上記移行時に、供給ガス圧の変動率を燃焼熱量の変動率に比べて小さくする。このような制御であれば、従来に比べて出湯温度は短時間だけ変動するものの、火移りを安定して行えるからである。
【００３９】
また、前述した実施形態での過渡的制御において、Ａ面，Ｂ面からＡ＋Ｂ面へと一旦燃焼領域を広げる制御部分は、燃焼領域の切り換えを伴わずに単にＢ面燃焼からＡ＋Ｂ面燃焼へと燃焼領域を広げる際に適用してもよい。この場合でも、火炎の安定化と火移りの確実性が得られる。
【００４０】
前述の実施形態では、二面三段燃焼切り替えを行える装置について説明したが、燃焼領域が３つ以上あるものに適用してもよい。
本発明は、共通の熱交換部に給湯回路と風呂追焚回路が通る一缶二水路型のガス給湯装置に適用してもよいし、給湯を目的としない燃焼装置例えば暖房装置に適用してもよい。
【００４１】
【発明の効果】
以上説明したように、請求項１の発明によれば、燃焼領域を切り換えるために、燃焼領域を一旦広げる際の過渡的制御において、供給ガス圧の変動を抑えることにより、火炎の安定化と火移りの確実性が得られ、燃焼領域の切り換え動作の信頼性を向上させることができる。
請求項２の発明によれば、燃焼熱量の小さな領域から大きな領域へと切り換える過渡的制御において、予め供給ガス圧を下げてから、隣接する２つの領域にガスを供給するので、この２つの領域にガスを供給した時に、大きな燃焼音が発生するのを防止できる。
請求項３の発明によれば、燃焼熱量の小さな領域から大きな領域へと切り換える過渡的制御において、隣接する２つの領域の燃焼から燃焼熱量の小さな領域での燃焼に移行する際に、供給ガス圧を減じるため、早く安定した通常燃焼制御に移行することができる。
請求項４の発明によれば、燃焼熱量の大きな領域から小さな領域へと切り換える過渡的制御において、予め供給ガス圧を上げてから、隣接する２つの領域にガスを供給するので、この２つの領域にガスを供給した時に、火炎の高さを高くすることができ、火移りをより一層確実に行うことができる。
請求項５の発明によれば、燃焼熱量の大きな領域から小さな領域へと切り換える過渡的制御において、隣接する２つの領域の燃焼から燃焼熱量の大きな領域での燃焼に移行する際に、供給ガス圧を上げるため、早く安定した通常燃焼制御に移行することができる。
請求項６の発明によれば、過渡的制御において、隣接する２つの隣接する領域での所定時間の燃焼において、供給ガス圧を減じるため、総燃焼熱量が一時的に上昇するのを抑制することができる。
請求項７の発明によれば、隣接する２つの領域への燃焼に移行する際の総燃焼熱量の変動率に比べて、供給ガス圧の変動率を小さくしたので、従来制御方式との明確な区別ができ、従来制御方式に比べて火移りを安定して確実に行うことができる。
請求項８の発明によれば、隣接する２つの領域への燃焼に移行する際に、供給ガス圧をほぼ等しくすることにより、火移りの確実性をより一層高めることができる。
請求項９の発明によれば、隣接する２つの領域への燃焼に移行する際に、比例弁への供給電流を所定量増大させることにより、比例弁からガス噴射部材までの圧力損失の増大分を補償して、ガス噴射部材からの供給ガス圧を実質的に等しくすることができ、火移りの確実性をさらに高めることができる。
請求項１０の発明によれば、給湯装置として用い、出湯温度を設定温度にするために燃焼領域の拡大や切り換えを行う際に、本発明の効果を発揮することができる。
【図面の簡単な説明】
【図１】この発明の一実施の形態をなすガス給湯装置で実行される燃焼領域の切り替え時の過渡的制御の詳細を示す図であり、（Ａ）は燃焼熱量の小さな領域から燃焼熱量の大きな領域への切り替え時の過渡的制御を示し、（Ｂ）は燃焼熱量の大きな領域から燃焼熱量の小さな領域への切り替え時の過渡的制御を示す。
【図２】同ガス給湯装置の概略構成図である。
【図３】同ガス給湯装置での燃焼領域の切り替え制御を概略的に示す図である。
【図４】比例弁電流値とファン回転数の関係を示す図である。
【符号の説明】
２燃焼部
２ａ，２ｂ領域
３熱交換部
４ファン（送風手段）
１０ガス供給手段
１１ノズルブロック（ガス噴射部材）
１１ａ，１１ｂ領域
１４比例弁
１５ａ，１５ｂ副開閉弁
２０給湯回路
３０制御ユニット（制御手段）
３５リモートコントローラ（温度設定手段）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas combustion apparatus including a combustion section having a plurality of regions where selective combustion is performed.
[0002]
[Prior art]
A gas combustion apparatus, for example, a gas hot water supply apparatus, includes a combustion section, a heat exchange section that receives combustion heat from the combustion section, a hot water supply circuit that passes through the heat exchange section, a gas supply means that supplies gas to the combustion section, and a combustion section And a control means for controlling the gas supply means and the blower means.
The control means controls the gas supply to the combustion unit in accordance with the amount of water flowing through the hot water supply circuit and changes the total amount of combustion heat so that the temperature of hot water discharged from the hot water supply circuit matches the set temperature. Specifically, the supply valve pressure to the combustion section is controlled by controlling the proportional valve of the gas supply means.
[0003]
By the way, there is a gas hot water supply apparatus in which a combustion section is divided into a plurality of regions having different combustion areas so that selective combustion can be performed. That is, in a state where combustion is performed in a small area, when the required combustion heat amount increases due to an increase in the amount of discharged hot water and the proportional valve current reaches near the upper limit value, switching to combustion in the large area area is performed. On the contrary, when combustion is performed in a large area, when the required combustion heat amount decreases due to a decrease in the amount of tapping water and the proportional valve current reaches near the lower limit, Switch to combustion.
[0004]
As described above, when switching the combustion region from one adjacent region to the other region, transient control is executed. That is, in a state where the gas supply to one region is continued and the flame in that region is maintained, the gas supply to the other region is performed to cause a fire transfer, and then the gas supply to one region is stopped. . At the time of this fire transfer, conventionally, in order to maintain the tapping temperature at a set temperature, fluctuations in the total amount of combustion heat are suppressed. That is, compared with combustion in one region, the combustion area increases in both regions. Therefore, the proportional valve current is decreased and the supply gas pressure is decreased in inverse proportion to the increase in the combustion area. The fluctuation of the is suppressed.
[0005]
[Problems to be solved by the invention]
As described above, there is the following inconvenience when the supply gas pressure is temporarily lowered when the combustion is transferred from the combustion in one region to the combustion in both regions to perform the fire transfer.
As shown in FIG. 4, the control means controls the rotation speed of the fan (control means), that is, the air flow rate (air pressure) so that it is proportional to the proportional valve current value, that is, the supply gas pressure. Combustion is performed at the fuel ratio. However, since there is a response delay of the fan (air blowing means) with respect to the control from the control means, the fan rotation speed (air flow rate) cannot follow the rapid fluctuation of the proportional valve current value (supply gas pressure). In other words, when the supply gas pressure is suddenly reduced during the above-mentioned fire transfer, the amount of blown air remains large corresponding to the previous supply gas pressure. As a result, not only the flame in the one region becomes unstable, but the gas ejected from the flame port in the other region contains excessive combustion air, so that the conditions for the transfer of fire are deteriorated. For this reason, the gas supply to one region may stop and combustion may be interrupted without the fire moving from one region to the other region.
[0006]
[Means for Solving the Problems]
The invention of claim 1 (A) a combustion section having a plurality of regions; (b) a gas supply means for supplying gas to the combustion section; (c) a blower means for supplying combustion air to the combustion section; and (d) the gas. The supply means is controlled to control the selective gas supply and supply gas pressure to a plurality of regions of the combustion section, and the blowing means is controlled to supply combustion air with an air volume corresponding to the supply gas pressure to the combustion section. The control means performs transient control when switching the combustion region from one adjacent region to the other region in the combustion section, and in the transient control, By supplying gas to the other region while maintaining the gas supply to the one region without greatly changing the supply gas pressure from the gas supply means to the combustion section, Fire to the other area Ri was allowed to occur, then, it is characterized by stopping the gas supply to the one region.
[0007]
Claim 2 The invention of claim 1 In the gas combustion apparatus according to claim 1, the control means switches from combustion in one region where the combustion heat amount is small to combustion in the other adjacent region where the combustion heat amount is large as the required total combustion heat amount increases. In this transient control, the supply gas pressure is reduced to a predetermined pressure in advance, and then the gas is supplied to the other region while maintaining the gas supply to the one region. It is characterized by causing fire transfer.
Claim 3 The invention of claim 1 or 2 In the gas combustion apparatus according to claim 1, the control means switches from combustion in one region where the combustion heat amount is small to combustion in the other adjacent region where the combustion heat amount is large as the required total combustion heat amount increases. In this transient control, the gas supply to the one region is performed from the combustion state in two adjacent regions. Stop In this case, the supply gas pressure is reduced.
Claim 4 The invention of claim 1 In the gas combustion apparatus described in the above, the control means switches from combustion in one region where the combustion heat amount is large to combustion in the other adjacent region where the combustion heat amount is small as the required total combustion heat amount decreases. In this transient control, the supply gas pressure is increased to a predetermined pressure in advance, and then the gas is supplied to the other region while maintaining the gas supply to the one region. It is characterized by causing fire transfer.
Claim 5 The invention of claim 1 or 4 In the gas combustion apparatus described in the above, the control means switches from combustion in one region where the combustion heat amount is large to combustion in the other adjacent region where the combustion heat amount is small as the required total combustion heat amount decreases. In this transient control, the gas supply to the one region is performed from the combustion state in two adjacent regions. Stop In this case, the supply gas pressure is increased.
[0008]
Claim 6 The invention of claim 1-5 In the gas combustion apparatus according to any one of the above, the control means reduces the supply gas pressure when the gas supply to the two adjacent regions is performed for a predetermined time in the transient control. To do.
Claim 7 The invention of claim 1-6 In the gas combustion apparatus according to any one of the above, when the gas is supplied to the other region while maintaining the gas supply to the one region in the transient control, the control means The variation rate of the supply gas pressure is made smaller than the variation rate of the total combustion heat quantity in the combustion section.
Claim 8 The invention of claim 7 In the gas combustion apparatus described in the above, when the gas is supplied to the other region while the gas supply to the one region is maintained in the transient control, the control means makes the supply gas pressure substantially equal. It is characterized by maintaining.
Claim 9 The invention of claim 8 In the gas combustion apparatus according to claim 1, the gas supply means includes a gas injection member having regions independent of each other of the combustion unit, and a proportional valve on the upstream side and a plurality of the gas injection members on the downstream side. Gas passages that communicate with each other via sub-open / close valves, and the control means controls the sub-open / close valve to select a combustion region of the combustion section and control the supply current to the proportional valve. The control means controls the supply gas pressure, and the control means performs the gas supply to the other region while maintaining the gas supply to the one region in the transient control. The supply current to the proportional valve is increased by a predetermined amount so that the supply gas pressure from the gas injection member becomes equal.
Claim 10 The invention of claim 1 to claim 1 9 In the gas combustion apparatus according to any one of the above, further, a heat exchange unit that receives combustion heat from the combustion unit, a hot water supply circuit that passes through the heat exchange unit, and a temperature setting unit that outputs set temperature information to the control unit And the control means controls the gas supply means so that the temperature of hot water discharged from the hot water supply circuit becomes a set temperature.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
A gas hot water supply device (gas combustion device) that constitutes an embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 2, the hot water supply apparatus includes a combustion unit 2 and a heat exchange unit 3 housed in the lower and upper portions of the casing 1, and a fan 4 (blower unit) connected to the bottom of the casing 1. Yes. The casing 1 is provided with a bypass path 5 that connects the upstream side and the downstream side of the combustion unit 2, and an air volume sensor 6 is provided in the bypass path 5.
[0010]
The combustion section 2 has two regions 2a and 2b (first and second regions) arranged separately on the left and right in the drawing. Assuming that the area of the region 2a is smaller than that of the region 2b and the supply gas pressure is constant, the amount of combustion heat in the region 2a is smaller than that of the region 2b.
In each of the regions 2a and 2b, flat dark burner elements and light burner elements are alternately arranged in the left-right direction in the drawing. Note that dark burner elements are arranged at both ends of each of the regions 2a and 2b. Therefore, dark burner elements are arranged at the boundary between the regions 2a and 2b.
The rich burner element has a narrow inlet for the combustion air so that the amount of gas increases with respect to the amount of combustion air when the optimum air-fuel ratio is used as a reference. The inlet for the combustion air is widened so that the amount of gas is reduced. In the light burner element, the flame from the flame mouth formed on the upper surface is high, and in the rich burner element, the flame is low and plays a role of supplementing the flame from the light burner element with gas fuel.
[0011]
The means 10 for supplying gas to the combustion section 2 includes a nozzle block 11 (gas injection member), a gas passage 12 connected to the nozzle block 11, and a main on-off valve 13 provided on the upstream side of the gas passage 12. And a proportional valve 14 (electromagnetic pressure proportional control valve) and two auxiliary on-off valves 15 a and 15 b provided on the downstream side of the gas passage 12. The nozzle block 11 is partitioned into two regions 11a and 11b, and these regions 11a and 11b are connected to the gas passage 11 via the auxiliary on-off valves 15a and 15b. Each area | region 11a, 11b of the nozzle block 11 has opposed the area | region 2a, 2b of the combustion part 2, and has a nozzle part which opposes the inlet of each burner element.
[0012]
A hot water supply circuit 20 passes through the heat exchange unit 3. The hot water supply circuit 20 is connected to a heat receiving pipe 21 that passes through the heat exchange unit 3, a water supply pipe 22 (upstream side, water supply side) connected to the inlet end of the heat receiving pipe 21, and an outlet end of the heat receiving pipe 21. It has a hot water supply pipe 23 (downstream side, hot water supply side) and a bypass pipe 24 connected in parallel with the heat receiving pipe 21 between the water supply pipe 22 and the hot water supply pipe 23. A hot water tap 25 is provided at the downstream end of the hot water supply pipe 23.
The water supply pipe 22 is provided with a temperature sensor 26 that detects the incoming water temperature, and a flow sensor 27 that detects a flow rate (amount of hot water) flowing through the hot water supply circuit 20. The hot water supply pipe 23 is provided with a temperature sensor 28 for detecting a tapping temperature and a gear motor drive type flow control valve 29.
[0013]
The gas hot water supply device further includes a control unit 30 (control means) including a microcomputer and a remote controller 35 (temperature setting means) for outputting set temperature information to the control unit 30.
[0014]
The control unit 30 is based on detection signals from the air volume sensor 6, temperature sensors 26 and 28, flow sensor 29 and set temperature information from the remote controller 35, and an ignition mechanism and gas supply system valves 13 and 14 (not shown). 15a and 15b are controlled (gas supply control, combustion control), the fan 4 is controlled (air flow control), and the flow rate control valve 29 is controlled (hot water control).
[0015]
Next, an outline of the gas supply control will be described with reference to FIG.
When the flow sensor 27 detects a water flow by opening the hot water tap 25, the control unit 30 performs an ignition operation in response to this, opens the main on-off valve 13, and opens one of the sub on-off valves 15a. Then, the gas from the gas passage 12 is supplied from one region 11a of the nozzle block 11 to one region 2a of the combustion unit 2, and combustion in this region 2a is performed. Based on the amount of water detected by the flow sensor 27, the incoming water temperature detected by the temperature sensor 26, and the set temperature from the remote controller 35, the feedforward control component is calculated, and the hot water detected by the temperature sensor 28 is calculated. A feedback control component is calculated based on the temperature and the set temperature. Then, the supply gas pressure from the region 11a of the nozzle block 11 is controlled by controlling the supply current to the proportional valve 14 based on the control value obtained by adding the feedforward control component and the feedback control component. The amount of combustion heat in the region 2a of the combustion unit 2 that is proportional to is controlled so that the temperature of hot water discharged from the hot water tap 25 matches the set temperature. Such feedforward control and control based on feedback control are referred to as normal combustion control in the following description.
[0016]
The outlet pressure of the proportional valve 14 is proportional to the supply current. The supply gas pressure at the nozzle portion of the nozzle block 11 is substantially equal to the outlet pressure of the proportional valve 14, but strictly speaking, the pressure loss in the path from the proportional valve 14 to the nozzle portion is determined from the outlet pressure of the proportional valve 14. Subtracted pressure.
[0017]
As described above, when the required combustion heat quantity is small, only the main on-off valve 13 and the sub on-off valve 15a are opened, and the sub on-off valve 15b is kept closed, so that combustion in one region 2a is performed. This combustion state is called A-side combustion.
In the A-side combustion, when the required amount of combustion heat increases, the supply gas pressure is increased by increasing the supply current to the proportional valve 14 accordingly, and consequently the total amount of combustion heat in the combustion section 2a is increased. Increase. As shown in FIG. 3, when the current supplied to the proportional valve 14 increases and the current value reaches (X1) and the total combustion heat amount reaches (Y1), the combustion region is switched. Schematically, the sub-open / close valve 15a is closed and the sub-open / close valve 15b is opened to switch from combustion in the small area 2a to combustion in the large area 2b (hereinafter referred to as B-side combustion). In this switching, complicated transient control is actually performed. This transient control is a feature of the present invention, and will be described in detail later.
[0018]
At the time when the switching to the B-side combustion is completed and the normal combustion control is returned to the stable state, the total combustion heat amount (Y2) in the B-side combustion is not substantially different from the total combustion heat amount (Y1) in the A-side combustion. In addition, the supply current value to the proportional valve 14 is reduced. That is, the supply current value to the proportional valve 14 is decreased in inverse proportion to the increase in the combustion area. The supply current value at this time is represented by (X2) in FIG.
[0019]
When the required combustion heat quantity is increased in the normal combustion control in the B-side combustion, the supply gas pressure is increased by increasing the supply current to the proportional valve 14 accordingly, and the total combustion heat quantity is increased accordingly. . When the supply current to the proportional valve 14 increases to reach the current value (X3) and the total amount of combustion heat reaches (Y3), the combustion region is switched. That is, the auxiliary on-off valve 15a is also opened to switch to combustion in the two regions 2a and 2b (hereinafter referred to as A + B surface combustion). In response to this switching, the supply current value to the proportional valve 14 is reduced so that the total combustion heat amount (Y4) in the A + B side combustion is not substantially different from the total combustion heat amount (Y3) in the B side combustion. The supply current value at this time is represented by (X4) in FIG.
In the A + B face combustion, when the temperature of the tapping water cannot be set to the set temperature even if the current value to the proportional valve 14 is maximized, the opening amount of the flow control valve 29 is narrowed to reduce the tapping amount. Ensure that the temperature matches the set temperature.
[0020]
Contrary to the above, when the supply current to the proportional valve 14 decreases and reaches (X5) in accordance with the decrease in the required combustion heat amount in the A + B side combustion, the mode is switched to the B side combustion. The combustion heat quantity (Y6) of this B-side combustion is substantially equal to the combustion heat quantity (Y5) in the A + B-side combustion, and the supply current to the proportional valve 14 is B-side combustion from the current value (X5) in the A + B-side combustion. Is increased in inverse proportion to the reduction of the combustion area. Note that the total combustion heat amounts (Y5) and (Y6) at the time of switching are smaller than the total combustion heat amounts (Y3) and (Y4) at the time of switching from the B-side combustion to the A + B-side combustion described above. Has hysteresis characteristics.
[0021]
Furthermore, when the supply current to the proportional valve 14 decreases and reaches (X7) in accordance with the decrease in the required amount of combustion heat in the B-side combustion, the mode is switched to the A-side combustion. The amount of combustion heat in the A-side combustion (Y8) and the amount of combustion heat in the B-side combustion (Y7) are approximately equal, and the supply current to the proportional valve 14 is determined from the current value (X7) in the B-side combustion. Side A It increases to the current value (X8) in combustion. The combustion heat amounts (Y7) and (Y8) at the time of switching are smaller than the combustion heat amounts (Y1) and (Y2) at the time of switching from the A-side combustion to the B-side combustion described above, and hysteresis characteristics are used for switching control. Is given.
When switching from the B-side combustion to the A-side combustion, a complicated transient control is actually performed. This transient control is also a feature of the present invention, and will be described in detail later. .
[0022]
The control unit 30 controls the fan 4 simultaneously with the gas supply control. That is, the fan 4 is controlled so that an air volume corresponding to the supply gas pressure is obtained, that is, an optimum air-fuel ratio is obtained. At this time, the air volume detected by the air volume sensor 6 is monitored, and the fan 4 is controlled so that the detected air volume matches the supply gas pressure.
[0023]
Next, transient control at the time of switching from A-side combustion to B-side combustion and at the time of switching from B-side combustion to A-side combustion, which characterizes the present invention, will be described. In such switching of the combustion region, the combustion region is stopped in combustion, and the region in the combustion stop state is in the combustion state. Therefore, transient control for surely performing the fire transfer is required. In this transient control, unlike the above-described normal combustion control, detection information and set temperature information are not used.
[0024]
First, switching from A-side combustion to B-side combustion will be described. As shown in FIG. 1A, first, the supply current to the proportional valve 14 in A-side combustion is reduced from the above-mentioned (X1) to a predetermined value (X11) (the opening degree of the proportional valve 14 is made almost half open). ). Next, by opening the sub-open / close valve 15b with the sub-open / close valve 15a open, gas is supplied not only to the region 2a of the combustion section 2 but also to the region 2b, and temporarily shifts from A-side combustion to A + B-side combustion. . That is, the fire transfer is executed.
During the transition from the A-side combustion to the A + B-side combustion, the supply current to the proportional valve 14 is not greatly changed, and the fluctuation of the supply gas pressure from the nozzle block 11 is suppressed.
[0025]
At the same time as the gas supply control, the control unit 30 controls the fan 4 to adjust the blown air volume according to the supply gas pressure so as to obtain the optimum air-fuel ratio. In the process of reducing the supply current to the proportional valve 14 from the above-described (X1) to the predetermined value (X11) in the A-side combustion, the blast volume decreases following this. This reduces the height of the flame in the combustion region 2a while maintaining a stable state.
When the gas supply state (A-side combustion state) to the region 2a is shifted to the gas supply state to the two regions 2a and 2b, fluctuations in the supply gas pressure are suppressed as described above. Therefore, it is not necessary to greatly change the air flow rate, and the response delay causes the flame in the region 2a to become unstable and the gas in the region 2b does not contain excessive combustion air. As described above, the flame transfer can be reliably performed by the stabilization of the flame in the region 2a and the ejection of the gas close to the optimum air-fuel ratio at the flame opening in the region 2b.
[0026]
In the present embodiment, the device is devised so that the fluctuation of the supply gas pressure from the nozzle block 11 before and after the transition is substantially zero (the supply gas pressure before and after the transition is substantially equal). . That is, if not only the sub-opening / closing valve 15a but also the sub-opening / closing valve 15b are opened without changing the supply current to the proportional valve 14 and the outlet pressure thereof, the gas flow rate increases, and accordingly the proportional valve 14 starts to the nozzle block. The pressure loss up to 11 nozzles increases, and the supply gas pressure at this nozzle decreases slightly. Therefore, in this embodiment, the supply current value is slightly increased from (X11) to (X12) to increase the outlet pressure of the proportional valve 14 in order to compensate for this increase in pressure loss. As a result, even when the sub open / close valve 15b is opened, the fluctuation of the supply gas pressure from the nozzle block 11 can be made zero. In this way, the stability of the flame can be maintained as much as possible, and the fire transfer can be further ensured.
[0027]
Further, in the present embodiment, as described above, prior to the opening operation of the sub on-off valve 15b, the supply current to the proportional valve 14 is reduced from (X1) to (X11), and the total combustion heat quantity is changed from (Y1) to (Y11). ), The amount of combustion heat (Y12) does not increase remarkably at the time of transition in the A + B surface combustion by the opening operation of the auxiliary on-off valve 15b, and the noise generated at the time of fire transfer can be suppressed to a small level. An instantaneous rise in temperature can also be suppressed.
[0028]
As described above, the supply current to the proportional valve 14 is ( X12 At the same time, after the auxiliary on-off valve 15b is opened, the supply current is reduced to (X13) and the heat of combustion is reduced to (Y13) in the course of a predetermined time secured for fire transfer. This is because the total combustion heat amount of the A + B surface combustion is larger than the required combustion heat amount, and therefore, the rise in the tapping temperature is suppressed by reducing the combustion heat amount as much as possible.
[0029]
As described above, after the A + B side combustion is performed for a relatively short time, the sub on-off valve 15a is closed to shift to the B side combustion. In this transition process, it is preferable that the supply gas pressure is not greatly changed from the viewpoint of stabilizing the flame. However, since it is after performing the above-mentioned fire transfer, it is not necessary to consider it very strictly. In this embodiment, the supply current to the proportional valve 14 is reduced from (X13) to (X14) to reduce the amount of combustion heat from (Y13) to (Y14), and then the supply current is changed to the normal combustion control. (X2), the amount of combustion heat (Y2) is reached quickly. In FIG. 1A, control indicated by a dotted line corresponds to transient control. In FIG. 3, this transient control is omitted and indicated by an arrow from the coordinates (X1, Y1) to (X2, Y2).
[0030]
Next, switching from B-side combustion to A-side combustion will be described. As shown in FIG. 1 (B), first, the supply current to the proportional valve 14 is increased from the aforementioned (X7) in the B-side combustion to the predetermined value (X15), and the opening degree of the proportional valve 14 is made almost half open. To do. Next, by opening the sub-open / close valve 15a with the sub-open / close valve 15b open, gas is supplied not only to the region 2b of the combustion section 2 but also to the region 2a to temporarily shift from B-side combustion to A + B-side combustion. . That is, the fire transfer is executed.
Even at the time of transition from the B-side combustion to the A + B-side combustion, the supply current to the proportional valve 14 is not greatly changed, and the fluctuation of the supply gas pressure from the nozzle block 11 is suppressed.
[0031]
In the process of increasing the supply current to the proportional valve 14 from the above-described (X7) to the predetermined value (X15) in the B-side combustion, the blast volume increases following this. This increases the height of the flame in the combustion region 2a while maintaining a stable state. And since the fluctuation | variation of the said supply gas pressure is suppressed when shifting from the gas supply state to the said area | region 2b, ie, a B surface combustion state, to the gas supply state to the two area | regions 2a and 2b, air flow rate is reduced. It is not necessary to make a large fluctuation, and the inconvenience due to the response delay of the blown air volume can be eliminated, and the fire transfer can be performed reliably.
[0032]
Also in the transition from the B-side combustion to the A + B-side combustion, the supply current value is slightly increased from (X15) to (X16), the outlet pressure of the proportional valve 14 is increased, and the nozzle block from the outlet of the proportional valve 14 is increased. The increase in pressure loss up to 11 nozzles is compensated. As a result, even when the sub-opening / closing valve 15a is opened, the fluctuation of the supply gas pressure from the nozzle block 11 can be made zero, the stability of the flame is maintained as much as possible, and the fire transfer is further ensured. be able to.
[0033]
In the present embodiment, as described above, since the supply current to the proportional valve 14 is increased from X7 to X15 (combustion heat amount Y15) prior to the opening operation of the auxiliary on-off valve 15a, the flame is increased. The fire transfer can be made even more reliable.
[0034]
As described above, the supply current to the proportional valve 14 is set to (X16), and at the same time the sub-opening / closing valve 15a is opened, the supply current is increased to (X17) in the process of lapse of a predetermined time secured for fire transfer. Reduce the combustion heat to (Y17). This is because the total combustion heat amount in the A + B surface combustion is larger than the required combustion heat amount, and therefore, the rise in the tapping temperature is suppressed by reducing the combustion heat amount as much as possible.
[0035]
As described above, after the A + B side combustion is performed for a relatively short time, the auxiliary on-off valve 15b is closed to shift to the A side combustion. In this transition process, the supply current to the proportional valve 14 is increased from (X17) to (X18) to increase the amount of combustion heat from (Y17) to (Y18), and then the transition to normal combustion control is performed. , To reach the supply current (X8) and the amount of combustion heat (Y8) earlier. In FIG. 1B, control indicated by a dotted line corresponds to transient control. In FIG. 3, this transient control is omitted, and an arrow from the coordinates (X7, Y7) to (X8, Y8) is shown.
[0036]
In the present embodiment, the dark burner elements are adjacent to each other at the boundary between the region 2a and the region 2b, so that it is relatively difficult for the fire to move. be able to.
[0037]
In addition, this invention is not limited to said embodiment, A design change is possible suitably.
For example, in the above transient control, the supply current to the proportional valve 14 does not have to be changed at the time of transition from A-side combustion to A + B-side combustion or at the time of transition from B-side combustion to A + B-side combustion. In this case, although the supply gas pressure at the nozzle portion of the nozzle block 11 is slightly reduced by the increase in pressure loss, it can be said that the supply gas pressure is substantially equal, and the fire transfer can be performed reliably.
[0038]
Conventionally, in transitional control accompanying combustion surface switching, when changing from A-side combustion to A + B-side combustion, or when shifting from B-side combustion to A + B-side combustion, the supply gas pressure is largely changed to substantially change the combustion heat amount. Zero. Comparing such a conventional example with the present invention, the control features of the present invention can be expressed as follows. That is, in the control according to the present invention, the fluctuation rate of the supply gas pressure is made smaller than the fluctuation rate of the combustion heat quantity at the time of the transition. This is because, with such control, although the tapping temperature fluctuates only for a short time compared to the conventional case, it is possible to perform the fire transfer stably.
[0039]
Further, in the transient control in the above-described embodiment, the control part that temporarily expands the combustion region from the A-side and B-side to the A + B-side is simply changed from the B-side combustion to the A + B-side combustion without switching the combustion region. You may apply when expanding a combustion area. Even in this case, flame stabilization and certainty of fire transfer can be obtained.
[0040]
In the above-described embodiment, an apparatus that can perform two-sided / three-stage combustion switching has been described.
The present invention may be applied to a canned and two-channel gas hot water supply device in which a hot water supply circuit and a bath remedy circuit pass through a common heat exchanging unit, or a combustion device not intended for hot water supply, such as a heating device. Also good.
[0041]
【The invention's effect】
As explained above, According to the invention of claim 1, In transitional control when the combustion region is temporarily expanded to switch the combustion region, by suppressing fluctuations in the supply gas pressure, flame stabilization and certainty of fire transfer can be obtained, and the reliability of the combustion region switching operation is reliable. Can be improved.
Claim 2 According to the invention, in the transient control for switching from the region where the combustion heat amount is small to the region where the combustion heat is large, the gas is supplied to the two adjacent regions after the supply gas pressure is lowered in advance. When supplied, it is possible to prevent generation of loud combustion noise.
Claim 3 According to the present invention, in the transient control for switching from the region where the combustion heat amount is small to the region where the combustion heat amount is large, when the transition from the combustion in the two adjacent regions to the combustion in the region where the combustion heat amount is small is reduced Thus, it is possible to shift to normal combustion control that is fast and stable.
Claim 4 According to the invention, in the transient control for switching from the region where the combustion heat is large to the region where the combustion heat amount is small, the gas is supplied to the two adjacent regions after the supply gas pressure is raised in advance. When supplied, the height of the flame can be increased, and the fire can be transferred more reliably.
Claim 5 According to the invention, in the transitional control for switching from the region where the combustion heat amount is large to the small region, the supply gas pressure is increased when the combustion in the two adjacent regions is shifted to the combustion in the region where the combustion heat amount is large. Thus, it is possible to shift to normal combustion control that is fast and stable.
Claim 6 According to the invention, in the transient control, the supply gas pressure is reduced in the combustion for a predetermined time in two adjacent regions, so that it is possible to suppress the total combustion heat quantity from temporarily rising.
Claim 7 According to the invention, since the fluctuation rate of the supply gas pressure is smaller than the fluctuation rate of the total combustion heat amount when shifting to the combustion in two adjacent regions, it is possible to clearly distinguish from the conventional control method. As compared with the conventional control method, the fire transfer can be performed stably and reliably.
Claim 8 According to this invention, when shifting to combustion in two adjacent regions, the reliability of fire transfer can be further improved by making the supply gas pressure substantially equal.
Claim 9 According to this invention, when shifting to combustion in two adjacent regions, the amount of increase in pressure loss from the proportional valve to the gas injection member is compensated by increasing the supply current to the proportional valve by a predetermined amount. Thus, the supply gas pressure from the gas injection member can be made substantially equal, and the reliability of fire transfer can be further increased.
Claim 10 According to the invention, the effect of the present invention can be exhibited when the combustion region is expanded or switched in order to use the hot water supply device as the preset temperature.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing details of transient control at the time of switching of a combustion region performed by a gas hot water supply device according to an embodiment of the present invention. The transient control at the time of switching to a large region is shown, and (B) shows the transient control at the time of switching from a region having a large amount of combustion heat to a region having a small amount of combustion heat.
FIG. 2 is a schematic configuration diagram of the gas hot-water supply device.
FIG. 3 is a diagram schematically showing switching control of a combustion region in the gas hot water supply device.
FIG. 4 is a diagram showing a relationship between a proportional valve current value and a fan rotational speed.
[Explanation of symbols]
2 Combustion section
2a, 2b area
3 Heat exchange section
4 Fan (Blowing means)
10 Gas supply means
11 Nozzle block (gas injection member)
11a, 11b area
14 Proportional valve
15a, 15b Sub-open / close valve
20 Hot water supply circuit
30 Control unit (control means)
35 Remote controller (temperature setting means)

Claims

(A) a combustion section having a plurality of regions;
(B) gas supply means for supplying gas to the combustion section;
(C) a blower means for supplying combustion air to the combustion section;
(D) Controlling the gas supply means to control selective gas supply and supply gas pressure to a plurality of regions of the combustion section, and controlling the blower means to control the amount of combustion air corresponding to the supply gas pressure Control means for supplying to the combustion section;
In a water heater with
The control means performs transient control when switching the combustion area from one adjacent area to the other area in the combustion section. In this transient control, the supply gas from the gas supply means to the combustion section is executed. By supplying gas to the other region while maintaining the gas supply to the one region without greatly changing the pressure, a fire transfer from the one region to the other region is caused. The gas combustion apparatus is characterized in that the gas supply to the one region is stopped.

The control means performs transient control for switching from combustion in one region where the combustion heat amount is small to combustion in the other adjacent region where the combustion heat amount is large as the required total combustion heat amount increases. In this transient control, the supply gas pressure is reduced to a predetermined pressure in advance, and then the gas supply to the other region is performed while maintaining the gas supply to the one region, thereby causing a fire transfer. The gas combustion apparatus according to claim 1 , wherein

The control means performs transient control for switching from combustion in one region where the combustion heat amount is small to combustion in the other adjacent region where the combustion heat amount is large as the required total combustion heat amount increases. in this transient control, the combustion state in the two adjacent areas, in stopping the gas supply to the one region above, according to claim 1 or 2, characterized in that reducing the feed gas pressure Gas combustion device.

The control means performs transient control for switching from combustion in one region where the combustion heat amount is large to combustion in the other adjacent region where the combustion heat amount is small as the required total combustion heat amount is reduced. In this transient control, the supply gas pressure is increased to a predetermined pressure in advance, and then the gas is supplied to the other region while maintaining the gas supply to the one region, thereby causing a fire transfer. The gas combustion apparatus according to claim 1 .

The control means performs transient control for switching from combustion in one region where the combustion heat amount is large to combustion in the other adjacent region where the combustion heat amount is small as the required total combustion heat amount is reduced. in this transient control, the combustion state in the two adjacent areas, in stopping the gas supply to the one region above, according to claim 1 or 4, characterized in that increasing the feed gas pressure Gas combustion equipment.

Said control means, in the transient control, when performing the gas supply to the two regions said adjacent predetermined time, according to claim 1, characterized in reducing the feed gas pressure Gas combustion equipment.

In the transient control, when the gas is supplied to the other region while maintaining the gas supply to the one region, the control means adjusts the fluctuation rate of the total combustion heat amount in the combustion section before and after the gas supply. The gas combustion apparatus according to any one of claims 1 to 6 , wherein a fluctuation rate of the supply gas pressure is made smaller than that of the gas combustion apparatus.

The control means maintains the supply gas pressure substantially equal when performing gas supply to the other region while maintaining gas supply to the one region in the transient control. Item 8. A gas combustion apparatus according to Item 7 .

The gas supply means includes a gas injection member having regions independent of each other of the combustion portion, and a proportional valve on the upstream side and sub-open / close valves on the downstream side in the plurality of regions of the gas injection member. And the control means selects the combustion region of the combustion section by controlling the auxiliary on-off valve, and controls the supply gas pressure by controlling the supply current to the proportional valve. ,
In addition, when the gas is supplied to the other region while maintaining the gas supply to the one region in the transient control, the control means supplies the gas pressure supplied from the gas injection member before and after the gas supply to the other region. 9. The gas combustion apparatus according to claim 8 , wherein the supply current to the proportional valve is increased by a predetermined amount so as to be equal.

Furthermore, a heat exchange unit that receives combustion heat from the combustion unit, a hot water supply circuit that passes through the heat exchange unit, and a temperature setting unit that outputs set temperature information to the control unit, the control unit includes the hot water supply unit The gas combustion apparatus according to any one of claims 1 to 9 , wherein the gas supply means is controlled so that a temperature of hot water discharged from the circuit becomes a set temperature.