JP3795817B2

JP3795817B2 - Gas combustion equipment

Info

Publication number: JP3795817B2
Application number: JP2002071970A
Authority: JP
Inventors: 友哉赤堀; 敬一伊藤; 春樹鵜生; 和記西尾; 秀一高田; 繁明安井; 一小林
Original assignee: Rinnai Corp
Current assignee: Rinnai Corp
Priority date: 2001-03-30
Filing date: 2002-03-15
Publication date: 2006-07-12
Anticipated expiration: 2022-03-15
Also published as: JP2002357319A

Description

【０００１】
【発明の属する技術分野】
本発明は、ガスコンセントと着脱自在に接続されたガスホースを介して燃料ガスが供給されるガス燃焼装置におけるバーナの失火処理に関する。
【０００２】
【従来の技術】
従来より、ガス温風暖房機やガスストーブ等のバーナにより燃料ガスを燃焼させるガス燃焼装置においては、バーナの燃焼状態を検出するセンサが設けられ、該バーナに点火されて燃焼運転が開始された後に該センサにより該バーナの失火が検知されたときに、バーナへの燃料ガスの供給を停止して使用者に装置に異常が生じたことを報知するようにしていた。
【０００３】
ここで、燃焼運転中にバーナが失火するのは、例えば燃焼用空気の取り入れ口に装着されたエアフィルタが閉塞して燃焼用空気の供給量が不足した場合のように、ガス燃焼装置に何らかの異常が生じたときである。そこで、バーナの失火が検知されたときに、上述したように報知を行なうことにより、使用者に対してガス燃焼装置の異常を解消するための処理を行なうことを促すことができる。
【０００４】
しかし、本願発明者らは、ガスコンセントと着脱自在に接続されたガスホースを介して燃料ガスが供給されるガス燃焼装置においては、該ガス燃焼装置自体に異常が生じていない場合であってもバーナの失火が生じ得ることを知見した。そして、このようにガス燃焼装置自体の異常以外の要因によってバーナが失火したときに異常の報知を行なうと、使用者はバーナの失火が生じた原因がわからないため、使用者に不安感を抱かせてしまうという不都合がある。
【０００５】
【発明が解決しようとする課題】
本発明は、上記不都合を解消し、ガス燃焼装置の異常が生じていない状態でバーナの失火が生じたときは、異常報知を行なわないようにしたガス燃焼装置を提供することを目的とする。
【０００６】
【課題を解決するための手段】
本発明は上記目的を達成するためになされたものであり、一端がガスコンセントと着脱自在に接続されたガスホースの他端と接続された接続口と、該接続口とガス供給管を介して接続されたバーナと、該ガス供給管を開閉する開閉弁と、該バーナの点火を行なう点火手段と、該バーナの燃焼状態を検出する燃焼状態検出手段と、前記点火手段により前記バーナに点火された後、前記燃焼状態検出手段により前記バーナの失火が検知されたときに、前記開閉弁を閉弁して異常報知を行なう失火対処処理を実行する失火対処手段とを備えたガス燃焼装置の改良に関する。
【０００９】
そして、本発明の第１の態様は、前記燃焼状態検出手段であって前記バーナの付近に設けられた熱電対と、前記点火手段により前記バーナに点火されて前記熱電対の出力電圧が所定の着火検知レベルまで上昇した後、所定時間内に、該熱電対の出力電圧が所定レベル低下したとき又は該熱電対の出力電圧が所定の基準変化率よりも大きい変化率で低下したときに、使用者が前記ガスホースを前記ガスコンセントから抜き差しすることによって前記ガスホース内に空気が流入し、前記ガスホース内の燃料ガスの濃度が前記接続口付近と前記ガスコンセント付近で高く両者の中間付近で低くなったエア噛み状態で前記バーナが点火された後に、濃度の低い燃料ガスが前記バーナに供給されて前記バーナの失火が生じたことを検知するエア噛み失火検知手段と、前記所定時間を燃料ガスの種類に応じて変更する所定時間変更手段と、前記エア噛み失火検知手段により前記バーナの失火が検知されたときに、前記失火対処手段による前記失火対処処理を禁止して、前記点火手段により前記バーナを再点火する再点火手段とを備えたことを特徴とする。
【００１０】
かかる本発明によれば、前記エア噛み失火検知手段は、前記熱電対の出力電圧が前記着火検知レベルまで上昇した後、前記所定時間内に、該熱電対の出力電圧が前記所定レベル低下したとき又は前記熱電対の出力電圧が前記基準変化率よりも大きい変化率で低下したときには、前記バーナが一旦着火した直後に失火したと想定できることから、前記エア噛み状態で前記バーナが点火された後に該バーナが失火したと判断することができる。そして、前記エア噛み検知手段により前記バーナの失火が検知されたときに、前記再点火手段により前記バーナが再点火される。そのため、使用者は前記エア噛み状態に起因して前記バーナが失火したときに前記バーナを再点火する処理を行なう必要がなく、使用者の使い勝手が向上する。また、燃料ガスの種類により、前記バーナの燃焼に必要な燃料ガスの供給量が異なるため、前記バーナが着火してから失火するまでに要する時間も相違する。そこで、前記所定時間を燃料ガスの種類に応じて変更する前期所定時間変更手段を備えることにより、燃料ガスの種類ごとに前記所定時間を適切に設定することができる。
【００１９】
また、本発明の第２の態様は、前記燃焼状態検出手段であって前記バーナの付近に設けられたフレームロッドと、前記点火手段により前記バーナに点火されて前記フレームロッドの通電量が所定の着火検知レベルまで上昇した後、所定時間内に、該フレームロッドの通電量が所定レベル低下したとき又は該フレームロッドの通電量が所定の基準変化率よりも大きい変化率で低下したときに、使用者が前記ガスホースを前記ガスコンセントから抜き差しすることによって前記ガスホース内に空気が流入し、前記ガスホース内の燃料ガスの濃度が前記接続口付近と前記ガスコンセント付近で高く両者の中間付近で低くなったエア噛み状態で前記バーナが点火された後に、濃度の低い燃料ガスが前記バーナに供給されて前記バーナの失火が生じたことを検知するエア噛み失火検知手段と、前記所定時間を燃料ガスの種類に応じて変更する所定時間変更手段と、前記エア噛み失火検知手段により前記バーナの失火が検知されたときに、前記失火対処手段による前記失火対処処理を禁止して、前記点火手段により前記バーナを再点火する再点火手段とを備えたことを特徴とする。
【００２０】
かかる本発明によれば、前記エア噛み失火検知手段は、前記フレームロッドの通電量が前記着火検知レベルまで上昇した後、前記所定時間内に、該フレームロッドの通電量が前記所定レベル低下したとき又は該フレームロッドの通電量が前記基準変化率よりも大きい変化率で低下したときには、前記バーナが一旦着火した直後に失火したと想定できることから、前記エア噛み状態で前記バーナが点火された後に該バーナが失火したと判断することができる。そして、前記第１の態様と同様に、前記再点火手段を備えることにより、使用者は前記エア噛み状態に起因して前記バーナが失火したときに前記バーナを再点火する処理を行なう必要がなく、使用者の使い勝手が向上する。また、燃料ガスの種類により、前記バーナの燃焼に必要な燃料ガスの供給量が異なるため、前記バーナが着火してから失火するまでに要する時間も相違する。そこで、前記所定時間を燃料ガスの種類に応じて変更する前期所定時間変更手段を備えることにより、燃料ガスの種類ごとに前記所定時間を適切に設定することができる。
【００２２】
また、本発明の第３の態様は、前記バーナは筐体内に配置され、該筐体の温度を検出する筐体温度検出手段と、前記バーナの燃焼中に前記バーナの燃焼中に該筐体温度検出手段の検出温度が所定の異常温度以上となったときに前記バーナの燃焼を停止する過熱停止手段と、前記点火手段により前記バーナに点火された後、前記筐体温度検出手段の検出温度が上昇から低下に転じて所定温度低下したとき、又は前記筐体温度検出手段の検出温度が上昇から低下に転じて所定の基準変化率よりも大きい変化率で低下したときに、使用者が前記ガスホースを前記ガスコンセントから抜き差しすることによって前記ガスホース内に空気が流入し、前記ガスホース内の燃料ガスの濃度が前記接続口付近と前記ガスコンセント付近で高く両者の中間付近で低くなったエア噛み状態で前記バーナが点火された後に、濃度の低い燃料ガスが前記バーナに供給されて該バーナの失火が生じたことを検知するエア噛み失火検知手段と、該エア噛み失火検知手段により前記バーナの失火が検知されたときに、前記失火対処手段による前記異常報知を禁止する異常報知禁止手段とを備えたことを特徴とする。
【００２３】
かかる本発明によれば、前記エア噛み状態で前記バーナに点火されると、前記筐体温度検出手段の検出温度は前記バーナの燃焼により前記筐体が加熱されるに従って上昇し、前記バーナが失火すると該検出温度は低下する。そこで、前記エア噛み検知手段は、前記筐体温度検出手段の検出温度が上昇から低下に転じて前記所定温度低下したとき、又は前記筐体温度検出手段の検出温度が上昇から低下に転じて前記基準変化率よりも大きい変化率で低下したときに、前記エア噛み状態で前記バーナが点火されて該バーナの失火が生じたと判断することができる。そして、前記異常報知禁止手段を備えることにより、前記ガス燃焼装置に異常が生じていないにも拘わらず異常報知がなされ、使用者に不安感を抱かせることを防止することできる。
【００２４】
また、本発明の第４の態様は、前記バーナは筐体内に配置され、該筐体の温度を検出する筐体温度検出手段と、前記バーナの燃焼中に前記バーナの燃焼中に該筐体温度検出手段の検出温度が所定の異常温度以上となったときに前記バーナの燃焼を停止する過熱停止手段と、前記点火手段により前記バーナに点火された後、前記筐体温度検出手段の検出温度が上昇から低下に転じて所定温度低下したとき、又は前記筐体温度検出手段の検出温度が上昇から低下に転じて所定の基準変化率よりも大きい変化率で低下したときに、使用者が前記ガスホースを前記ガスコンセントから抜き差しすることによって前記ガスホース内に空気が流入し、前記ガスホース内の燃料ガスの濃度が前記接続口付近と前記ガスコンセント付近で高く両者の中間付近で低くなったエア噛み状態で前記バーナが点火された後に、濃度の低い燃料ガスが前記バーナに供給されて該バーナの失火が生じたことを検知するエア噛み失火検知手段と、該エア噛み失火検知手段により前記バーナの失火が検知されたときに、前記失火対処手段による前記失火対処処理を禁止して、前記点火手段により前記バーナを再点火する再点火手段とを備えたことを特徴とする。
【００２５】
かかる本発明によれば、前記エア噛み状態で前記バーナに点火されると、前記筐体温度検出手段の検出温度は前記バーナの燃焼により前記筐体が加熱されるに従って上昇し、前記バーナが失火すると該検出温度は低下する。そこで、前記エア噛み検知手段は、前記筐体温度検出手段の検出温度が上昇から低下に転じて前記所定温度低下したとき、又は前記筐体温度検出手段の検出温度が上昇から低下に転じて前記基準変化率よりも大きい変化率で低下したときに、前記エア噛み状態で前記バーナが点火されて該バーナの失火が生じたと判断することができる。そして、前記第１の態様と同様に、前記再点火手段を備えることにより、使用者は前記エア噛み状態に起因して前記バーナが失火したときに前記バーナを再点火する処理を行なう必要がなく、使用者の使い勝手が向上する。
【００２６】
【発明の実施の形態】
本発明の実施の形態の一例について図１〜図５を参照して説明する。図１は本発明のガス燃焼装置である温風暖房機の全体構成図、図２は図１に示した温風暖房機の制御ブロック図、図３はエア噛み状態に起因してバーナが失火したことを検知する方法を説明するためのグラフ、図４〜図５はエア噛み状態で運転スイッチが操作されたときの温風暖房機の作動を示したフローチャートである。
【００２７】
図１を参照して、本実施の形態の温風暖房機は室内で使用されるものであり、本体ケース１内に、ダクト２、送風ファン３（本発明の空気供給ファン及び送風ファンの機能を含む）、バーナ４、ガス供給管５、及びコントローラ６を備え、本体ケース１の外面に操作パネル７を備えている。
【００２８】
ダクト２は温風の送風路を構成するものであり、室内空気ｓを取り込むための吸気口８を本体ケース１の背面に開口し、本体ケース１の前面下部において温風の吹出口９を開口している。吸気口８には塵や埃がダクト２内に流入するのを防ぐためにエアフィルタ（図示しない）が取付けられており、吸気口８の付近に室内空気ｓの温度を室温として検出し、検出信号をコントローラ６に出力する室温センサ１０が取付けられている。
【００２９】
送風ファン３はファンモータ１１により回転駆動され、吸気口８からダクト２内に室内空気ｓを吸引してダクト２内に組み込まれたバーナ４の燃焼排気と混合し、混合空気を温風ｍとして吹出口９から室内に送出する。ファンモータ１１にはその回転数を検出する回転数センサ１２が設けられ、回転数センサ１２はファンモータ１１の回転数の検出信号をコントローラ６に出力する。
【００３０】
ダクト２内に組み込まれたバーナ４は、燃焼胴１３（本発明の燃焼室を形成する）内に燃焼プレート１４を備え、バーナ４の燃焼排気が燃焼胴１３からダクト２内に排出される。また、燃焼プレート１４の近傍には、燃焼用空気と燃料ガスとの混合気に点火するための点火電極１５と、バーナ４の燃焼状態を検出するための熱電対１６（本発明の燃焼状態検出手段に相当する）とが設けられている。熱電対１６は、バーナ４の燃焼炎に晒されたときに燃焼炎の温度に応じた熱起電力を発生し、該熱起電力をコントローラ６に出力する。
【００３１】
バーナ４には、ガス供給管５の先端に取付けられたノズル１７から噴出される燃料ガスと、送風ファン３の回転により吸気口８から取り込まれた燃焼用空気とが混合されて供給される。ガス供給管５には、上流側から、電磁弁１８，１９（本発明の開閉弁に相当する）及びガス比例弁２０（本発明の燃料供給量調節手段に相当する）が設けられている。
【００３２】
電磁弁１８，１９はコントローラ６からの通電により開弁するものであり、開弁状態ではガス供給管５を開けて燃料ガスをノズル１７に通過させ、通電が遮断された閉弁状態ではガス供給管５を閉じて燃料ガスの通過を遮断する。また、ガス比例弁２０は、コントローラ６からの通電量に比例してその開度が増大するものであり、コントローラ６はガス比例弁２０の開度を通電制御してバーナ４への燃料ガスの供給量を調節する。
【００３３】
また、ガス供給管５は、その先端の接続口３０によりガスホース３１の一端と接続され、ガスホース３１の他端は室内の壁面等に設けられたワンタッチ式のガスコンセント３２と着脱自在に接続されている。
【００３４】
操作パネル７には、暖房運転の開始／停止を指示するための運転スイッチ２１、タイマ運転における暖房開始時刻を設定するためのタイマスイッチ２３、目標暖房温度の設定を変更するための温度（＋）スイッチ２４及び温度（−）スイッチ２５等のスイッチ類が配設され、また、運転状況等を表示するための表示器２６とブザー２７が配設されている。
【００３５】
次に、図２を参照して、コントローラ６はマイクロコンピュータ等を用いて構成された電子ユニットであり、燃焼制御手段４０、失火対処手段４１、エア噛み失火検知手段４２、再点火手段４３、データメモリ４４、及びガス種設定スイッチ４５を備えている。
【００３６】
データメモリ４４には、目標暖房温度と室温センサ１０の検出温度との差に応じてバーナ４の必要燃焼量を決定するために使用されるガス比例弁２０への通電量とガス比例弁２０の２次圧（燃料ガスの供給量に比例する）との関係を示すデータテーブルが、複数の燃料ガスの種類ごとに記憶されている。
【００３７】
そして、燃焼制御手段４０は、ガス種設定スイッチ４５により選択された燃料ガスの種類に応じた前記データテーブルを使用してガス比例弁２０に出力する通電量を決定し、バーナ４の燃焼制御を行なう。
【００３８】
また、失火対処手段４１は、暖房運転中に熱電対１６の出力電圧を監視し、熱電対１６の出力電圧が所定の失火検知レベル以下に低下したときに、電磁弁１８，１９を閉弁して燃料ガスの供給を停止すると共にブザー２７及び表示器２６により異常の報知を行なう。これにより、失火対処手段４１は、例えば吸気口８の閉塞等の異常が生じてバーナ４が失火したときに、バーナ４への燃料ガスの供給を停止して、使用者に温風暖房機の異常が生じたことを知らせるようにしている。
【００３９】
また、エア噛み失火検知手段４２は、図１を参照して、例えば室内を清掃する際に、使用者がガスホース３１をガスコンセント３２から抜き差ししたことによって、ガスホース３１内の接続口３０付近とガスコンセント３２付近に濃度が高い燃料ガスが滞留し、その間に挟まれたガスホース３１の中間部分に濃度が低い燃料ガスが滞留したエア噛み状態となり、このエア噛み状態で暖房運転が開始されてバーナ４の失火が生じたことを検知するものである。
【００４０】
エア噛み状態で暖房運転が開始されると、先ず、接続口３０付近に滞留していた濃度が高い燃料ガスがバーナ４に供給されてバーナ４が着火する。しかし、濃度が高い燃料ガスに続いてガスホース３１の中間部分に滞留していた濃度が低い燃料ガスがバーナ４に供給されるため、バーナ４は失火する。
【００４１】
そこで、エア噛み失火検知手段４２は、バーナ４の点火処理がなされたときに熱電対１６の出力電圧の推移を監視することによって、エア噛み状態でバーナ４が着火された後に濃度が低い燃料ガスがバーナ４に供給されてバーナ４が失火したことを検知する。
【００４２】
図３は、エア噛み状態でバーナ４が着火されたときの熱電対１６の出力電圧の推移を示したグラフであり、横軸が時間（ｔ）、縦軸が熱電対１６の出力電圧（Ｖ_TC）である。バーナ４が着火すると（時刻ｔ₁₀）、バーナ４の燃焼炎に晒されて熱電対１６の温度が上がるため、それに応じて熱電対１６の出力電圧が上昇する。そして、着火検知レベル（Ｖ_B）を超えて（時刻ｔ₁₁）上昇するが、ガスホース３１に滞留していた濃度が低い燃料ガスが供給され始めるとバーナ４は失火し、熱電対１６の出力電圧は上昇から下降に転じる（時刻ｔ₁₂）。
【００４３】
そこで、エア噛み失火検知手段４２は、バーナ４に点火されて熱電対１６の出力電圧が着火検知レベル（Ｖ_B）に達して（ｔ₁₁）から所定時間内に所定レベル（Ｖα）低下したときに（ｔ₁₃）、エア噛み状態でバーナ４に点火されてバーナ４の失火が生じたことを検知する。なお、前記所定時間は、ガス種設定スイッチ４５（本発明の所定時間変更手段の機能を含む）により設定された燃料ガスの種類に応じて変更される。
【００４４】
そして、このように、エア噛み状態でバーナ４に点火されてバーナ４が失火した場合に、失火対処手段４１によって上述したように異常報知を行なうと、実際には温風暖房機に異常は生じていないため、使用者を混乱させてしまう。その上、使用者は再度運転スイッチ２１を操作して暖房運転の開始を指示しなければならないという煩わしさもある。
【００４５】
そこで、再点火手段４３は、エア噛み失火検知手段４２により、エア噛み状態でバーナ４に点火されてバーナ４の失火が生じたことが検知されたときは、失火対処手段４１による電磁弁１８，１９の閉弁と、表示器２６及びブザー２７による失火エラーの報知を禁止して、バーナ４の再点火を行なう。以下、図４〜図５に示したフローチャートに従って、エア噛み状態で使用者が運転スイッチ２１をＯＮ操作したときの温風暖房機の作動について説明する。
【００４６】
図４を参照して、使用者が運転スイッチ２１をＯＮ操作して暖房運転の開始を指示すると、ＳＴＥＰ１からＳＴＥＰ２に進み、コントローラ６はバーナ２の点火処理を行なう。すなわち、ＳＴＥＰ２で着火検知タイマをスタートし、ＳＴＥＰ３でファンモータ１１をＯＮし、ＳＴＥＰ４で点火電極１５をＯＮして火花放電を生じさせた状態で、ＳＴＥＰ５で電磁弁１８，１９及びガス比例弁２０を開弁する。
【００４７】
そして、コントローラ６は、ＳＴＥＰ７で着火検知タイマのタイムアップの有無を確認しながらＳＴＥＰ６で熱電対１６の出力電圧（Ｖ_TC）が着火検知レベル（Ｖ_B）以上となるのを待つ。
【００４８】
ＳＴＥＰ６で熱電対１６の出力電圧（Ｖ_TC）が着火検知レベル（Ｖ_B）以上となったときはＳＴＥＰ２０に分岐し、コントローラ６は点火電極１５をＯＦＦして点火処理を終了し、図５のＳＴＥＰ２１に進む。一方、ＳＴＥＰ６で熱電対１６の出力電圧（Ｖ_TC）が着火検知レベル（Ｖ_B）以上となったことが検知されずに、ＳＴＥＰ７で着火検知タイマがタイムアップしたときには、バーナ４の着火に失敗したと判断されてＳＴＥＰ８に進み、失火対処手段４１により、ＳＴＥＰ８で電磁弁１８，１９及びガス比例弁２０が閉弁され、ＳＴＥＰ９で送風ファンがＯＦＦされ、ＳＴＥＰ１０でブザー２７と表示器２６により異常報知がなされる。
【００４９】
図５のＳＴＥＰ２１〜ＳＴＥＰ２３はエア噛み失火検知手段４２による処理である。エア噛み失火検知手段４２は、ＳＴＥＰ２１でエア噛みタイマをスタートし、ＳＴＥＰ２３で該エア噛みタイマのタイムアップの有無を確認しながら、ＳＴＥＰ２２で熱電対１６の出力電圧Ｖ_TCがＶα低下したか否かを監視する。そして、熱電対１６の出力電圧Ｖ_TCがＶα低下したときは、エア噛み失火検知手段４２は、上述したようにエア噛み状態でバーナ４が着火して失火が生じたと検知してＳＴＥＰ３０に分岐する。
【００５０】
ＳＴＥＰ３０〜ＳＴＥＰ３２は再点火手段４３による処理であり、再点火手段４３は、ＳＴＥＰ３０で電磁弁１８，１９とガス比例弁２０を閉弁し、ＳＴＥＰ３１で送風ファン３により燃焼胴１３内をプリパージして、ＳＴＥＰ３２でバーナ４の再点火処理を行なう。この場合、失火対処手段４１による異常報知は行なわれない（禁止される）ので、使用者に混乱を与えることはなく、また、自動的に再点火処理が行なわれるので、使用者は再度運転スイッチ２１を操作して暖房運転の開始を指示する必要がない。
【００５１】
また、ＳＴＥＰ２２で熱電対１６の出力電圧Ｖ_TCがＶα低下せずに、ＳＴＥＰ２３でエア噛みタイマがタイムアップしたときは、エア噛み状態ではなかったと判断できるので、ＳＴＥＰ２４に進んでコントローラ６は暖房運転を開始する。
【００５２】
なお、本実施の形態では、図５に示したように、エア噛み状態でバーナ４に着火されてバーナ４の失火が生じたことが検知されたときに、一旦電磁弁１８，１９とガス比例弁２０を閉弁してプリパージを行なってからバーナ４の再点火を行なったが（ＳＴＥＰ３０〜ＳＴＥＰ３２）、電磁弁１８，１９及びガス比例弁２０を開弁状態に維持し、プリパージを行なわずにバーナ４の再点火処理を行なうようにしてもよい。この場合には、バーナ４が失火してから再点火されるまでに要する時間を短くすることができる。さらにこの場合、ガス比例弁の開度を大きくしてもよく、これにより、ガスホース３１内に滞留した濃度の低い燃料ガスをより速くバーナ４から排出することができるため、バーナ４が失火してから再点火されるまでに要する時間をさらに短縮することができる。
【００５３】
また、本実施の形態では、図３に示したように、エア噛み失火検知手段４２は、熱電対１５の出力電圧（Ｖ_TC）が所定レベル（Ｖα）低下したときに、エア噛み状態でバーナ４が着火されて失火したと検知したが、図６に示したように、熱電対１５の出力電圧（Ｖ_TC）が所定の基準変化率よりも大きい変化率で下降したとき（ΔＶ_TC／Δｔ＞基準変化率）に、エア噛み状態でバーナ４に着火されて失火が生じたと検知してもよい。
【００５４】
また、本実施の形態では、熱電対１５の出力電圧（Ｖ_TC）を監視してエア噛み状態でバーナ４に着火されて失火が生じたことを検知したが、温風暖房機から送出される温風ｍ（図１参照）の温度を検出する温風温度センサ５０（図１、図２参照、本発明の温風温度検出手段に相当する）を設け、該温風温度センサ５０の検出温度を監視してエア噛み状態でバーナ４に着火されて失火が生じたことを検知するようにしてもよい。
【００５５】
図７の▲１▼は、エア噛み状態でバーナ４が着火された場合の温風温度センサ５０の検出温度の推移を示したグラフであり、縦軸は温風温度センサ５０の検出温度、横軸が時間である。接続口３０付近に滞留していた濃度の高い燃料ガスによりバーナ４に着火されると（時刻ｔ₃₀）、温風ｍの温度が次第に上昇して温風温度センサの検出温度が上昇する。そして、ガスホース３１の中間部付近に滞留していた濃度の低い燃焼ガスがバーナ４に供給されてバーナ４が失火すると、温風ｍの温度は下降し始める。
【００５６】
そこで、エア噛み失火検知手段４２は、バーナ４が着火された後の温風温度センサ５０の検出温度を監視し、該検出温度が上昇から低下に転じてから（時刻ｔ₃₁）Ｔα（本発明の所定温度に相当する）低下したとき（時刻ｔ₃₂）に、エア噛み状態でバーナ４に着火されてバーナ４の失火が生じたと判断するようにしてもよい。さらに、温風温度センサ５０の検出温度が上昇から下降に転じてから該検出温度が所定の基準変化率よりも大きい変化率で低下したときに、エア噛み状態でバーナ４に着火されて失火が生じたと判断してもよい。
【００５７】
また、本実施の形態では、エア噛み失火検知手段４２により、エア噛み状態でバーナ４に着火されてバーナ４の失火が生じたことが検知されたときに、失火対処手段４１による失火エラーの報知と電磁弁１８，１９及びガス比例弁２０の閉弁を禁止して、バーナ４の再点火処理を行なうようにしたが、失火エラーの報知のみを禁止して電磁弁１８，１９及びガス比例弁２０を閉弁し、バーナ４の再点火処理を行なわないようにする場合にも、本発明の効果を得ることができる。この場合、使用者は運転スイッチ２１をＯＮ操作する必要があるが、異常報知はなされないので、使用者を混乱させることはない。
【００５８】
また、本実施の形態では、本発明の燃焼状態検出手段として熱電対１６を用いたが、バーナ４の燃焼炎の状態に応じて通電量が変化するフレームロッドを用いてバーナ４の燃焼状態を検出するようにしてもよい。そして、この場合は、バーナ４の着火処理がなされてフレームロッドの通電量が予め設定された着火検知レベルまで上昇してから、所定時間内に所定レベル低下したとき又は所定の基準変化率よりも大きい変化率で低下したときに、エア噛み状態でバーナ４に点火されてバーナ４の失火が生じたと検知することができる。
【００５９】
このように、フレームロッドを用いた場合、バーナ４の燃焼炎の有無を直接的に検知できるため、熱電対１６や温風温度センサ５０を用いる場合よりも短時間でバーナ４の失火を検知することができる。
【００６０】
なお、フレームロッドを用いる場合も、ガス種設定スイッチ４５（本発明の所定時間変更手段の機能を含む）により設定された燃料ガスの種類に応じて前記所定時間を変更してもよい。
【００６１】
また、図１に示したように、バーナ４が収容されたダクト２（本発明の筐体に相当する）の温度を検出するハイリミットセンサ５１（本発明の筐体温度検出手段に相当する）を備え、バーナ４の燃焼中にハイリミットセンサ５１の検出温度が予め設定された過熱異常温度以上となったときに、図２に示した過熱停止手段５５によりバーナ４の燃焼を停止して温風暖房機を保護するように構成した場合には、該ハイリミットセンサ５１の検出温度からエア噛みによるバーナ４の失火を検知するようにしてもよい。
【００６２】
図７の▲２▼は、エア噛み状態でバーナ４が着火された場合のハイリミットセンサ５１の検出温度の推移を示したグラフであり、縦軸はハイリミットセンサ５１の検出温度、横軸は時間である。エア噛み状態でバーナ４に着火されると（時刻ｔ₃₀）、バーナ４により加熱されてダクト２の温度は上昇するが、ガスホース３１の中間部付近に滞留していた濃度の低い燃料ガスがバーナ４に供給されてバーナ４が失火すると（時刻ｔ₃₁）、ダクト２の温度は下降し始める。
【００６３】
そのため、エア噛み失火検知手段４２は、バーナ４が着火された後のハイリミットセンサ５１の検出温度を監視し、該検出温度が上昇から低下に転じてから（時刻ｔ₃₁）Ｔβ（本発明の所定温度に相当する）低下したとき（時刻ｔ₃₂）に、エア噛み状態でバーナ４に着火されてバーナ４の失火が生じたと判断するようにしてもよい。さらに、ハイリミットセンサ５１の検出温度が上昇から下降に転じてから該検出温度が所定の基準変化率よりも大きい変化率で低下したときに、エア噛み状態でバーナ４に着火されて失火が生じたと判断してもよい。
【００６４】
また、本実施の形態では、本発明のガス燃焼装置として温風暖房機を示したが、ガスストーブ等、ガスコンセントと着脱自在に接続されたガスホースと接続され、該ガスコンセントから供給される燃料ガスを燃焼させる燃焼装置であれば、本発明の適用が可能である。
【図面の簡単な説明】
【図１】本発明のガス燃焼装置である温風暖房機の全体構成図
【図２】図１に示したガス温風暖房機の制御ブロック図
【図３】エア噛み状態に起因してバーナが失火したことを検知する方法を説明するためのグラフ。
【図４】図１に示したガス温風暖房機における再点火処理の実行フローチャート。
【図５】図１に示したガス温風暖房機における再点火処理の実行フローチャート。
【図６】エア噛み状態に起因してバーナが失火したことを検知する方法を説明するためのグラフ。
【図７】エア噛み状態に起因してバーナが失火したことを検知する方法を説明するためのグラフ。
【符号の説明】
４…バーナ、１６…熱電対、１８，１９…電磁弁、２０…ガス比例弁、３０…接続口、３１…ガスホース、３２…ガスコンセント、４１…失火対処手段、４２…エア噛み失火検知手段、４３…再点火手段、５０…温風温度センサ、５１…ハイリミットセンサ、５５…過熱停止手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a burner misfire treatment in a gas combustion apparatus to which fuel gas is supplied through a gas hose removably connected to a gas outlet.
[0002]
[Prior art]
Conventionally, in a gas combustion apparatus that burns fuel gas with a burner such as a gas hot air heater or a gas stove, a sensor for detecting the combustion state of the burner is provided, and the burner is ignited to start a combustion operation. When the misfire of the burner is detected later by the sensor, the supply of fuel gas to the burner is stopped to notify the user that an abnormality has occurred in the apparatus.
[0003]
Here, the burner misfires during the combustion operation, for example, when the air filter attached to the intake port of the combustion air is closed and the supply amount of the combustion air is insufficient. This is when an abnormality occurs. Therefore, when the misfire of the burner is detected, notification is made as described above, thereby prompting the user to perform processing for eliminating the abnormality of the gas combustion device.
[0004]
However, the inventors of the present invention have disclosed a burner in which a fuel gas is supplied via a gas hose that is detachably connected to a gas outlet, even if there is no abnormality in the gas combustion device itself. It was discovered that misfire could occur. And if the burner misfires due to factors other than the malfunction of the gas combustion device itself in this way, the user will not know the cause of the burner misfire, so the user will be anxious There is an inconvenience.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a gas combustion device that eliminates the above-mentioned disadvantages and that does not notify the abnormality when a burner misfires in a state where no abnormality has occurred in the gas combustion device.
[0006]
[Means for Solving the Problems]
  The present invention has been made to achieve the above object, and has a connection port connected to the other end of the gas hose, one end of which is detachably connected to the gas outlet, and the connection port is connected to the gas supply pipe through the connection port. Burner, an on-off valve for opening and closing the gas supply pipe, ignition means for igniting the burner, combustion state detecting means for detecting the combustion state of the burner, and the burner being ignited by the ignition means Thereafter, when misfire of the burner is detected by the combustion state detecting means, a misfire handling process is performed in which the on-off valve is closed to notify the abnormality.Misfire prevention measures to be implementedThe present invention relates to an improvement of a gas combustion apparatus provided.
[0009]
  In the first aspect of the present invention, the combustion state detecting means is a thermocouple provided in the vicinity of the burner, and the burner is ignited by the ignition means, and the output voltage of the thermocouple is a predetermined value. Used when the output voltage of the thermocouple decreases by a predetermined level within a predetermined time after rising to the ignition detection level or when the output voltage of the thermocouple decreases at a change rate larger than a predetermined reference change rate. When a person inserts and removes the gas hose from the gas outlet, air flows into the gas hose, and the concentration of the fuel gas in the gas hose is high near the connection port and near the gas outlet, and low near the middle of both. An air bite misfire that detects that the burner has been misfired after a low concentration of fuel gas is supplied to the burner after the burner is ignited in the air bite state And intellectual means,Predetermined time changing means for changing the predetermined time according to the type of fuel gas; andRe-ignition means for prohibiting the misfire handling process by the misfire handling means and reigniting the burner by the ignition means when the misfire of the burner is detected by the air biting misfire detection means. Features.
[0010]
  According to the present invention, the air bite misfire detection means is configured to detect when the output voltage of the thermocouple drops to the predetermined level within the predetermined time after the output voltage of the thermocouple has increased to the ignition detection level. Alternatively, when the output voltage of the thermocouple decreases at a rate of change greater than the reference rate of change, it can be assumed that the burner has misfired immediately after igniting, so the burner is ignited after the burner is ignited. It can be determined that the burner misfired. Then, when the misfiring of the burner is detected by the air biting detection means, the burner is reignited by the reignition means. Therefore, the user does not need to perform a process of reigniting the burner when the burner misfires due to the air-engaged state, and the convenience of the user is improved.In addition, since the amount of fuel gas supplied for burning the burner varies depending on the type of fuel gas, the time required from the ignition of the burner to misfire also varies. Therefore, the predetermined time can be appropriately set for each type of fuel gas by providing a predetermined period changing unit for changing the predetermined time according to the type of fuel gas.
[0019]
  Further, the second aspect of the present invention is the combustion state detecting means, a frame rod provided in the vicinity of the burner, and the burner being ignited by the ignition means so that the energization amount of the frame rod is a predetermined amount. Used when the energization amount of the frame rod decreases by a predetermined level or the energization amount of the frame rod decreases at a change rate larger than a predetermined reference change rate within a predetermined time after rising to the ignition detection level. When a person inserts and removes the gas hose from the gas outlet, air flows into the gas hose, and the concentration of the fuel gas in the gas hose is high near the connection port and near the gas outlet, and low near the middle of both. After the burner was ignited in the air-engaged state, a low-concentration fuel gas was supplied to the burner, causing the burner to misfire. And the air biting misfire detection means to detect,Predetermined time changing means for changing the predetermined time according to the type of fuel gas; andRe-ignition means for prohibiting the misfire handling process by the misfire handling means and reigniting the burner by the ignition means when the misfire of the burner is detected by the air biting misfire detection means. Features.
[0020]
  According to the present invention, the air biting misfire detection means is configured to detect when the energization amount of the frame rod decreases to the predetermined level within the predetermined time after the energization amount of the frame rod has increased to the ignition detection level. Alternatively, when the energization amount of the frame rod decreases at a rate of change larger than the reference rate of change, it can be assumed that the burner has misfired immediately after it has ignited, so the burner is ignited after the burner is ignited. It can be determined that the burner misfired. As in the first aspect, by providing the reignition means, the user does not need to perform a process of reigniting the burner when the burner misfires due to the air biting state. , User convenience is improved.In addition, since the amount of fuel gas supplied for burning the burner varies depending on the type of fuel gas, the time required from the ignition of the burner to misfire also varies. Therefore, the predetermined time can be appropriately set for each type of fuel gas by providing a predetermined period changing unit for changing the predetermined time according to the type of fuel gas.
[0022]
  Also,According to a third aspect of the present invention, the burner is disposed in a casing, and the casing temperature detection means for detecting the temperature of the casing, and the casing temperature detection during combustion of the burner during combustion of the burner. An overheat stop means for stopping combustion of the burner when the detected temperature of the means exceeds a predetermined abnormal temperature, and the detected temperature of the casing temperature detecting means rises after the burner is ignited by the ignition means The user turns the gas hose when the gas hose is lowered when the temperature of the casing temperature detecting means falls from a rise to a fall, or when the detected temperature of the housing temperature detection means turns from rise to fall and falls at a rate of change greater than a predetermined reference change rate. By inserting and removing from the gas outlet, air flows into the gas hose, and the concentration of the fuel gas in the gas hose is high near the connection port and near the gas outlet, and low near the middle of both. After the burner is ignited in an air-engaged state, an air-engagement misfire detection means for detecting that a low-concentration fuel gas is supplied to the burner and the misfire of the burner has occurred, and the air-engagement misfire detection means An abnormality notification prohibiting means for prohibiting the abnormality notification by the misfire countermeasure means when a misfire of the burner is detected.It is characterized by that.
[0023]
  According to the present invention,When the burner is ignited in the air-engaged state, the temperature detected by the casing temperature detecting means increases as the casing is heated by combustion of the burner, and when the burner misfires, the detected temperature decreases. . Therefore, the air biting detection unit is configured such that when the detection temperature of the casing temperature detection unit changes from rising to lowering and the predetermined temperature decreases, or the detection temperature of the casing temperature detection unit changes from rising to lowering. When the rate of change is greater than the reference rate of change, it can be determined that the burner has been misfired due to the burner being ignited in the air-engaged state. By providing the abnormality notification prohibiting means, it is possible to prevent the user from feeling uneasy even if the abnormality is not generated in the gas combustion apparatus, and to prevent the user from feeling uneasy.
[0024]
  Also,The fourth aspect of the present invention is:The burner is arranged in a casing, and a casing temperature detecting means for detecting the temperature of the casing, and the detected temperature of the casing temperature detecting means during combustion of the burner during the combustion of the burner is a predetermined abnormal temperature Overheat stopping means for stopping combustion of the burner when,After the ignition means ignites the burner, when the temperature detected by the casing temperature detecting means changes from rising to lowering to a predetermined temperature, or the temperature detected by the casing temperature detecting means changes from rising to lowering. When the rate of change is greater than the predetermined reference rate,When a user inserts and removes the gas hose from the gas outlet, air flows into the gas hose, and the concentration of the fuel gas in the gas hose is high near the connection port and near the gas outlet, and low near the middle of both. After the burner is ignited in an air-engaged state, an air-engagement misfire detection means for detecting that a low-concentration fuel gas is supplied to the burner and the misfire of the burner has occurred, and the air-engagement misfire detection means Re-ignition means for prohibiting the misfire countermeasure processing by the misfire countermeasure means and reigniting the burner by the ignition means when the misfire of the burner is detected.It is characterized by that.
[0025]
  According to the present invention, when the burner is ignited in the air-engaged state, the temperature detected by the casing temperature detecting means rises as the casing is heated by combustion of the burner, and the burner misfires. Then, the detected temperature decreases. Therefore, the air biting detection unit is configured such that when the detection temperature of the casing temperature detection unit changes from rising to lowering and the predetermined temperature decreases, or the detection temperature of the casing temperature detection unit changes from rising to lowering. When the rate of change is greater than the reference rate of change, it can be determined that the burner has been misfired due to the burner being ignited in the air-engaged state.As in the first aspect, by providing the reignition means, the user does not need to perform a process of reigniting the burner when the burner misfires due to the air biting state. , User convenience is improved.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
An example of an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram of a hot air heater as a gas combustion apparatus of the present invention, FIG. 2 is a control block diagram of the hot air heater shown in FIG. 1, and FIG. 3 is a burner misfire due to an air-engaged state FIG. 4 to FIG. 5 are flowcharts illustrating the operation of the hot air heater when the operation switch is operated in the air-engaged state.
[0027]
Referring to FIG. 1, the hot air heater of the present embodiment is used indoors, and in body case 1, duct 2, blower fan 3 (the functions of the air supply fan and the blower fan of the present invention). A burner 4, a gas supply pipe 5, and a controller 6, and an operation panel 7 is provided on the outer surface of the main body case 1.
[0028]
The duct 2 constitutes a hot air blowing path, and an intake port 8 for taking in indoor air s is opened at the back of the main body case 1, and a hot air outlet 9 is opened at the lower front of the main body case 1. is doing. An air filter (not shown) is attached to the intake port 8 to prevent dust and dust from flowing into the duct 2. The temperature of the indoor air s is detected as a room temperature near the intake port 8, and a detection signal is detected. Is attached to the controller 6.
[0029]
The blower fan 3 is rotationally driven by a fan motor 11, sucks indoor air s from the air inlet 8 into the duct 2, mixes it with the combustion exhaust of the burner 4 incorporated in the duct 2, and uses the mixed air as hot air m. It sends out from the blower outlet 9 into the room. The fan motor 11 is provided with a rotation speed sensor 12 for detecting the rotation speed, and the rotation speed sensor 12 outputs a detection signal of the rotation speed of the fan motor 11 to the controller 6.
[0030]
The burner 4 incorporated in the duct 2 includes a combustion plate 14 in a combustion cylinder 13 (forming the combustion chamber of the present invention), and combustion exhaust from the burner 4 is discharged from the combustion cylinder 13 into the duct 2. Further, in the vicinity of the combustion plate 14, an ignition electrode 15 for igniting a mixture of combustion air and fuel gas, and a thermocouple 16 for detecting the combustion state of the burner 4 (the combustion state detection of the present invention). Corresponding to the means). The thermocouple 16 generates a thermoelectromotive force corresponding to the temperature of the combustion flame when exposed to the combustion flame of the burner 4, and outputs the thermoelectromotive force to the controller 6.
[0031]
The burner 4 is supplied with a mixture of the fuel gas ejected from the nozzle 17 attached to the tip of the gas supply pipe 5 and the combustion air taken in from the intake port 8 by the rotation of the blower fan 3. The gas supply pipe 5 is provided with solenoid valves 18 and 19 (corresponding to the on-off valve of the present invention) and a gas proportional valve 20 (corresponding to the fuel supply amount adjusting means of the present invention) from the upstream side.
[0032]
The solenoid valves 18 and 19 are opened by energization from the controller 6. In the opened state, the gas supply pipe 5 is opened to allow the fuel gas to pass through the nozzle 17. In the closed state where the energization is interrupted, the gas supply is performed. The pipe 5 is closed to block the passage of fuel gas. Further, the opening of the gas proportional valve 20 increases in proportion to the energization amount from the controller 6, and the controller 6 controls the energization of the opening of the gas proportional valve 20 to supply the fuel gas to the burner 4. Adjust the supply amount.
[0033]
The gas supply pipe 5 is connected to one end of a gas hose 31 through a connection port 30 at the tip, and the other end of the gas hose 31 is detachably connected to a one-touch type gas outlet 32 provided on a wall surface of the room. Yes.
[0034]
The operation panel 7 includes an operation switch 21 for instructing start / stop of the heating operation, a timer switch 23 for setting the heating start time in the timer operation, and a temperature (+) for changing the setting of the target heating temperature. Switches such as a switch 24 and a temperature (−) switch 25 are disposed, and an indicator 26 and a buzzer 27 for displaying an operation status and the like are disposed.
[0035]
Next, referring to FIG. 2, the controller 6 is an electronic unit configured using a microcomputer or the like, and includes a combustion control means 40, a misfire countermeasure means 41, an air biting misfire detection means 42, a reignition means 43, data A memory 44 and a gas type setting switch 45 are provided.
[0036]
In the data memory 44, the energization amount to the gas proportional valve 20 used for determining the necessary combustion amount of the burner 4 according to the difference between the target heating temperature and the temperature detected by the room temperature sensor 10 and the gas proportional valve 20 are stored. A data table indicating the relationship with the secondary pressure (proportional to the supply amount of fuel gas) is stored for each of a plurality of types of fuel gas.
[0037]
And the combustion control means 40 determines the energization amount output to the gas proportional valve 20 using the said data table according to the kind of fuel gas selected by the gas type setting switch 45, and performs the combustion control of the burner 4 Do.
[0038]
Further, the misfire countermeasure means 41 monitors the output voltage of the thermocouple 16 during the heating operation, and closes the solenoid valves 18 and 19 when the output voltage of the thermocouple 16 falls below a predetermined misfire detection level. Then, the supply of the fuel gas is stopped and the abnormality is notified by the buzzer 27 and the display 26. Thereby, the misfire countermeasure means 41 stops the supply of the fuel gas to the burner 4 when an abnormality such as the blockage of the intake port 8 occurs, for example, and the burner 4 is misfired. It is informed that an abnormality has occurred.
[0039]
In addition, referring to FIG. 1, the air biting misfire detection means 42 is connected to the vicinity of the connection port 30 in the gas hose 31 and the gas when the user inserts and removes the gas hose 31 from the gas outlet 32 when cleaning the room, for example. A fuel gas with a high concentration stays in the vicinity of the outlet 32, and an air-engaged state in which a fuel gas with a low concentration stays in the middle portion of the gas hose 31 sandwiched between them, and the heating operation is started in this air-engaged state, and the burner 4 It detects that misfire has occurred.
[0040]
When the heating operation is started in the air-engaged state, first, the high concentration fuel gas staying in the vicinity of the connection port 30 is supplied to the burner 4 and the burner 4 is ignited. However, since the low concentration fuel gas staying in the middle portion of the gas hose 31 is supplied to the burner 4 following the high concentration fuel gas, the burner 4 misfires.
[0041]
Therefore, the air bite misfire detection means 42 monitors the transition of the output voltage of the thermocouple 16 when the burner 4 is ignited, so that the fuel gas having a low concentration after the burner 4 is ignited in the air bite state. Is supplied to the burner 4 to detect that the burner 4 has misfired.
[0042]
FIG. 3 is a graph showing the transition of the output voltage of the thermocouple 16 when the burner 4 is ignited in the air-engaged state, with the horizontal axis representing time (t) and the vertical axis representing the output voltage (V_TC). When burner 4 ignites (time t_Ten) Since the temperature of the thermocouple 16 is increased by being exposed to the combustion flame of the burner 4, the output voltage of the thermocouple 16 is increased accordingly. And the ignition detection level (V_B) (Time t₁₁) Rises, but when the low concentration fuel gas staying in the gas hose 31 begins to be supplied, the burner 4 misfires, and the output voltage of the thermocouple 16 changes from rising to falling (time t)₁₂).
[0043]
Therefore, the air biting misfire detection means 42 is ignited by the burner 4 and the output voltage of the thermocouple 16 is set to the ignition detection level (V_B) (T₁₁) When a predetermined level (Vα) falls within a predetermined time (t₁₃), The burner 4 is ignited in the air-engaged state, and it is detected that the burner 4 has misfired. The predetermined time is changed according to the type of fuel gas set by the gas type setting switch 45 (including the function of the predetermined time changing means of the present invention).
[0044]
In this way, when the burner 4 is ignited in the air-engaged state and the burner 4 misfires, if the abnormality notification is performed by the misfire countermeasure means 41 as described above, an abnormality actually occurs in the hot air heater. Not confusing the user. In addition, there is also the annoyance that the user must operate the operation switch 21 again to instruct the start of the heating operation.
[0045]
Therefore, the reignition means 43, when the air biting misfire detection means 42 detects that the burner 4 is ignited in the air biting state and the burner 4 is misfired, 19 is closed, and a misfire error notification by the indicator 26 and the buzzer 27 is prohibited, and the burner 4 is re-ignited. Hereinafter, according to the flowchart shown in FIGS. 4-5, the action | operation of a warm air heater when a user carries out ON operation of the operation switch 21 in an air biting state is demonstrated.
[0046]
Referring to FIG. 4, when the user turns on operation switch 21 to instruct the start of the heating operation, the process proceeds from STEP 1 to STEP 2, and controller 6 performs an ignition process for burner 2. That is, the ignition detection timer is started at STEP2, the fan motor 11 is turned on at STEP3, the ignition electrode 15 is turned on at STEP4, and spark discharge is generated, and then the solenoid valves 18, 19 and the gas proportional valve 20 are produced at STEP5. Open the valve.
[0047]
Then, the controller 6 confirms whether or not the ignition detection timer has timed out in STEP 7 and in STEP 6 outputs the output voltage (V_TC) Is the ignition detection level (V_B) Wait for the above.
[0048]
In STEP6, the output voltage (V_TC) Is the ignition detection level (V_B), The process branches to STEP 20, where the controller 6 turns off the ignition electrode 15, ends the ignition process, and proceeds to STEP 21 in FIG. On the other hand, in STEP6, the output voltage (V_TC) Is the ignition detection level (V_B) If the ignition detection timer has timed out in STEP 7 without detecting that the above has been reached, it is determined that ignition of the burner 4 has failed, and the process proceeds to STEP 8 where the misfire countermeasure means 41 causes the solenoid valve 18, 19 and the gas proportional valve 20 are closed, the blower fan is turned off in STEP 9, and an abnormality is notified by the buzzer 27 and the display 26 in STEP 10.
[0049]
STEP 21 to STEP 23 in FIG. 5 are processes by the air biting misfire detection means 42. The air biting misfire detection means 42 starts the air biting timer at STEP 21 and confirms whether or not the air biting timer has timed out at STEP 23, while at STEP 22 confirms the output voltage V of the thermocouple 16._TCIt is monitored whether Vα has decreased. And the output voltage V of the thermocouple 16_TCWhen Vα decreases, the air biting misfire detection means 42 detects that the burner 4 has ignited in the air biting state and a misfire has occurred as described above, and branches to STEP 30.
[0050]
STEP 30 to STEP 32 are processes by the re-ignition means 43. The re-ignition means 43 closes the solenoid valves 18 and 19 and the gas proportional valve 20 at STEP 30, and pre-purges the inside of the combustion cylinder 13 with the blower fan 3 at STEP 31. In step 32, the burner 4 is re-ignited. In this case, since the malfunction notification by the misfire countermeasure means 41 is not performed (prohibited), the user is not confused, and the reignition process is automatically performed. There is no need to operate 21 to instruct the start of the heating operation.
[0051]
In STEP 22, the output voltage V of the thermocouple 16 is_TCIf the air biting timer expires in STEP 23 without Vα being lowered, it can be determined that the air biting state has not occurred, so the routine proceeds to STEP 24 where the controller 6 starts the heating operation.
[0052]
In the present embodiment, as shown in FIG. 5, when it is detected that the burner 4 is ignited in the air-engaged state and the burner 4 is misfired, the solenoid valves 18 and 19 are once in proportion to the gas. The burner 4 was re-ignited after the valve 20 was closed and pre-purged (STEP 30 to STEP 32), but the solenoid valves 18 and 19 and the gas proportional valve 20 were kept open without performing pre-purge. You may make it perform the reignition process of the burner 4. FIG. In this case, the time required from when the burner 4 is misfired to when it is reignited can be shortened. Furthermore, in this case, the opening of the gas proportional valve may be increased, whereby the low-concentration fuel gas retained in the gas hose 31 can be discharged from the burner 4 more quickly. It is possible to further reduce the time required from the start to reignition.
[0053]
Further, in the present embodiment, as shown in FIG. 3, the air biting misfire detection means 42 outputs the output voltage (V_TC) Is reduced by a predetermined level (Vα), it is detected that the burner 4 is ignited and misfires in the air-engaged state. However, as shown in FIG. 6, the output voltage (V_TC) Drops at a rate of change greater than a predetermined reference rate of change (ΔV_TC/ Δt> reference change rate), it may be detected that the burner 4 is ignited and misfire occurs in the air-engaged state.
[0054]
In the present embodiment, the output voltage (V_TC) Is detected and the burner 4 is ignited in the air-engaged state and it is detected that misfire has occurred, but the hot air temperature sensor detects the temperature of the hot air m (see FIG. 1) sent from the hot air heater. 50 (refer to FIG. 1 and FIG. 2, corresponding to the hot air temperature detecting means of the present invention), the temperature detected by the hot air temperature sensor 50 is monitored, and the burner 4 is ignited in the air-engaged state to cause misfire. May be detected.
[0055]
(1) in FIG. 7 is a graph showing the transition of the detected temperature of the hot air temperature sensor 50 when the burner 4 is ignited in the air-engaged state, and the vertical axis indicates the detected temperature of the hot air temperature sensor 50 and the horizontal The axis is time. When the burner 4 is ignited by the high-concentration fuel gas remaining in the vicinity of the connection port 30 (time t₃₀), The temperature of the hot air m gradually rises and the temperature detected by the hot air temperature sensor rises. When the low concentration combustion gas staying in the vicinity of the middle portion of the gas hose 31 is supplied to the burner 4 and the burner 4 misfires, the temperature of the hot air m begins to fall.
[0056]
Therefore, the air biting misfire detection means 42 monitors the temperature detected by the hot air temperature sensor 50 after the burner 4 is ignited, and after the detected temperature has changed from rising to lowering (time t₃₁) When Tα (corresponding to the predetermined temperature of the present invention) decreases (time t₃₂), The burner 4 may be ignited in the air-engaged state and it may be determined that the burner 4 has misfired. Further, when the detected temperature of the hot air temperature sensor 50 changes from rising to falling, when the detected temperature decreases at a change rate larger than a predetermined reference change rate, the burner 4 is ignited in the air-engaged state and misfire occurs. It may be determined that it has occurred.
[0057]
Further, in the present embodiment, when the air biting misfire detection means 42 detects that the burner 4 is ignited in the air biting state and the burner 4 is misfired, the misfire handling means 41 notifies the misfire error. The solenoid valves 18 and 19 and the gas proportional valve 20 are prohibited from being closed and the burner 4 is re-ignited, but only the misfire error notification is prohibited and the solenoid valves 18 and 19 and the gas proportional valve are prohibited. The effect of the present invention can also be obtained when the valve 20 is closed and the reignition process of the burner 4 is not performed. In this case, the user needs to turn on the operation switch 21, but no abnormality notification is made, so that the user is not confused.
[0058]
In the present embodiment, the thermocouple 16 is used as the combustion state detection means of the present invention. However, the combustion state of the burner 4 is determined by using a frame rod whose energization amount changes according to the state of the combustion flame of the burner 4. You may make it detect. In this case, after the ignition process of the burner 4 is performed and the energization amount of the frame rod rises to a preset ignition detection level, it falls below a predetermined level within a predetermined time or a predetermined reference change rate. When it decreases at a large rate of change, it can be detected that the burner 4 is ignited in the air-engaged state and the misfire of the burner 4 has occurred.
[0059]
As described above, when the flame rod is used, the presence or absence of the combustion flame of the burner 4 can be directly detected. Therefore, the misfire of the burner 4 is detected in a shorter time than when the thermocouple 16 or the hot air temperature sensor 50 is used. be able to.
[0060]
Even when a frame rod is used, the predetermined time may be changed according to the type of fuel gas set by the gas type setting switch 45 (including the function of the predetermined time changing means of the present invention).
[0061]
Further, as shown in FIG. 1, a high limit sensor 51 (corresponding to the casing temperature detecting means of the present invention) for detecting the temperature of the duct 2 (corresponding to the casing of the present invention) in which the burner 4 is accommodated. And the combustion of the burner 4 is stopped by the overheat stop means 55 shown in FIG. 2 when the temperature detected by the high limit sensor 51 becomes equal to or higher than the preset overheating abnormal temperature during the combustion of the burner 4. When the wind heater is configured to be protected, the misfire of the burner 4 due to the air biting may be detected from the temperature detected by the high limit sensor 51.
[0062]
(2) in FIG. 7 is a graph showing the transition of the detected temperature of the high limit sensor 51 when the burner 4 is ignited in the air-engaged state, the vertical axis is the detected temperature of the high limit sensor 51, and the horizontal axis is It's time. When the burner 4 is ignited in the air biting state (time t₃₀When the burner 4 is heated and the temperature of the duct 2 rises, the low concentration fuel gas staying in the vicinity of the middle portion of the gas hose 31 is supplied to the burner 4 and the burner 4 misfires (time t).₃₁), The temperature of the duct 2 begins to fall.
[0063]
Therefore, the air biting misfire detection means 42 monitors the detected temperature of the high limit sensor 51 after the burner 4 is ignited, and after the detected temperature has changed from rising to decreasing (time t₃₁) When Tβ (corresponding to the predetermined temperature of the present invention) decreases (time t₃₂), The burner 4 may be ignited in the air-engaged state and it may be determined that the burner 4 has misfired. Further, when the detected temperature of the high limit sensor 51 has changed from rising to lowering and the detected temperature has decreased at a rate of change greater than a predetermined reference rate of change, the burner 4 is ignited in the air-engaged state and misfire occurs. You may decide that
[0064]
In the present embodiment, the hot air heater is shown as the gas combustion apparatus of the present invention. However, the fuel supplied from the gas outlet is connected to a gas hose such as a gas stove that is detachably connected to the gas outlet. The present invention can be applied to any combustion apparatus that burns gas.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a hot air heater which is a gas combustion apparatus of the present invention.
FIG. 2 is a control block diagram of the gas hot air heater shown in FIG.
FIG. 3 is a graph for explaining a method of detecting that a burner has misfired due to an air biting state.
FIG. 4 is an execution flowchart of a reignition process in the gas hot air heater shown in FIG. 1;
FIG. 5 is an execution flowchart of reignition processing in the gas hot air heater shown in FIG. 1;
FIG. 6 is a graph for explaining a method of detecting that a burner has misfired due to an air biting state.
FIG. 7 is a graph for explaining a method of detecting that a burner has misfired due to an air biting state.
[Explanation of symbols]
4 ... burner, 16 ... thermocouple, 18, 19 ... solenoid valve, 20 ... gas proportional valve, 30 ... connection port, 31 ... gas hose, 32 ... gas outlet, 41 ... misfire countermeasure means, 42 ... air bite misfire detection means, 43 ... Reignition means, 50 ... Hot air temperature sensor, 51 ... High limit sensor, 55 ... Overheat stop means

Claims

A connection port connected to the other end of the gas hose, one end of which is detachably connected to the gas outlet, a burner connected to the connection port via a gas supply pipe, and an on-off valve for opening and closing the gas supply pipe, Ignition means for igniting the burner; combustion state detection means for detecting the combustion state of the burner;
After the ignition means is ignited by the ignition means, when the combustion state detection means detects the misfire of the burner, the misfire countermeasure means for executing the misfire countermeasure processing for closing the on-off valve to notify the abnormality In a gas combustion apparatus equipped with
A thermocouple provided in the vicinity of the burner as the combustion state detection means;
When the output voltage of the thermocouple decreases to a predetermined level within a predetermined time after the output voltage of the thermocouple is increased to a predetermined ignition detection level after the burner is ignited by the ignition means, or the output of the thermocouple When the voltage drops at a change rate greater than a predetermined reference change rate, the user inserts and removes the gas hose from the gas outlet so that air flows into the gas hose, and the concentration of the fuel gas in the gas hose is reduced. After the burner was ignited in an air-engaged state that was high near the connection port and near the gas outlet and low near the middle of the two, low-concentration fuel gas was supplied to the burner, causing misfiring of the burner Air bit misfire detection means for detecting
Predetermined time changing means for changing the predetermined time according to the type of fuel gas;
When the misfire of the burner is detected by the air trapping misfire detecting means that, prohibits the misfire coping process by the misfire remedy unit, and a re-ignition means for re-igniting the burner by the ignition means A gas combustion apparatus characterized by the above.

A connection port connected to the other end of the gas hose, one end of which is detachably connected to the gas outlet, a burner connected to the connection port via a gas supply pipe, and an on-off valve for opening and closing the gas supply pipe, Ignition means for igniting the burner; combustion state detection means for detecting the combustion state of the burner;
After the ignition means is ignited by the ignition means, when the combustion state detection means detects the misfire of the burner, the misfire countermeasure means for executing the misfire countermeasure processing for closing the on-off valve to notify the abnormality In a gas combustion apparatus equipped with
A flame rod provided in the vicinity of the burner as the combustion state detection means;
After the burner is ignited by the ignition means and the energization amount of the frame rod rises to a predetermined ignition detection level, the energization amount of the frame rod falls within a predetermined time, or when the energization of the frame rod decreases When the amount drops at a rate of change greater than a predetermined reference rate of change, the user inserts and removes the gas hose from the gas outlet, so that air flows into the gas hose, and the concentration of the fuel gas in the gas hose After the burner was ignited in an air-engaged state that was high near the connection port and near the gas outlet and low near the middle of the two, low-concentration fuel gas was supplied to the burner, causing misfiring of the burner Air bit misfire detection means for detecting
Predetermined time changing means for changing the predetermined time according to the type of fuel gas;
When the misfire of the burner is detected by the air trapping misfire detecting means that, prohibits the misfire coping process by the misfire remedy unit, and a re-ignition means for re-igniting the burner by the ignition means A gas combustion apparatus characterized by the above.

A connection port connected to the other end of the gas hose, one end of which is detachably connected to the gas outlet, a burner connected to the connection port via the gas supply pipe, and an on-off valve for opening and closing the gas supply pipe, Ignition means for igniting the burner; combustion state detection means for detecting the combustion state of the burner;
Gas combustion provided with misfire countermeasure means for closing the on-off valve and reporting abnormality when the burner is detected by the combustion state detecting means after the burner is ignited by the ignition means In the device
The burner is arranged in a casing, and a casing temperature detecting means for detecting the temperature of the casing, and the detected temperature of the casing temperature detecting means during combustion of the burner during the combustion of the burner is a predetermined abnormal temperature Overheat stop means for stopping the combustion of the burner when
After the ignition means ignites the burner, when the temperature detected by the casing temperature detecting means changes from rising to lowering to a predetermined temperature, or the temperature detected by the casing temperature detecting means changes from rising to lowering. When the user falls at a change rate larger than a predetermined reference change rate, the user inserts and removes the gas hose from the gas outlet so that air flows into the gas hose, and the concentration of the fuel gas in the gas hose After the burner was ignited in an air-engaged state that was high near the connection port and near the gas outlet and low near the middle of the two, low-concentration fuel gas was supplied to the burner, resulting in a misfire of the burner Air bit misfire detection means for detecting
A gas combustion apparatus, comprising: an abnormality notification prohibiting means for prohibiting the abnormality notification by the misfire countermeasure means when the air biting misfire detection means detects a misfire of the burner.

A connection port connected to the other end of the gas hose, one end of which is detachably connected to the gas outlet, a burner connected to the connection port via the gas supply pipe, and an on-off valve for opening and closing the gas supply pipe, Ignition means for igniting the burner; combustion state detection means for detecting the combustion state of the burner;
After the ignition means is ignited by the ignition means, when the combustion state detection means detects the misfire of the burner, the misfire countermeasure means for executing the misfire countermeasure processing for closing the on-off valve to notify the abnormality In a gas combustion apparatus equipped with
The burner is arranged in a casing, and a casing temperature detecting means for detecting the temperature of the casing, and the detected temperature of the casing temperature detecting means during combustion of the burner during the combustion of the burner is a predetermined abnormal temperature Overheat stop means for stopping the combustion of the burner when
After the ignition means ignites the burner, when the temperature detected by the casing temperature detecting means changes from rising to lowering to a predetermined temperature, or the temperature detected by the casing temperature detecting means changes from rising to lowering. When the user falls at a change rate larger than a predetermined reference change rate, the user inserts and removes the gas hose from the gas outlet so that air flows into the gas hose, and the concentration of the fuel gas in the gas hose After the burner was ignited in an air-engaged state that was high near the connection port and near the gas outlet and low near the middle of the two, low-concentration fuel gas was supplied to the burner, resulting in a misfire of the burner Air bit misfire detection means for detecting
Re-ignition means for prohibiting the misfire countermeasure processing by the misfire countermeasure means and reigniting the burner by the ignition means when the misfiring of the burner is detected by the air biting misfire detection means. A gas combustion apparatus characterized by the above.