JP3665699B2 - Deterioration diagnosis method for fuel cell power generator and reformer - Google Patents

Description

【０００５】
この水素リッチな改質ガスには、燃料電池セルスタック２１の燃料極１８の触媒の劣化原因となる一酸化炭素が含まれているので、改質ガスはシフト触媒（銅−亜鉛系触媒）が充填されたシフトコンバータ１１に送られ、次式に示すシフト反応により改質ガス中の一酸化炭素が二酸化炭素に変換される。
【０００６】
【数２】

【０００７】
シフトコンバータ１１により、改質ガス中の一酸化炭素濃度は１％以下まで低減される。シフトコンバータ１１を出た改質ガスは、燃料電池セルスタック２１の燃料極１８に供給され、燃料電池の発電に利用される。また、シフトコンバータ出口ガスの一部は脱硫装置７にリサイクルされ、リサイクルガス中の水素が脱硫反応に使用される。リサイクルガスの供給量は、予め設定された流量制御弁５２の開度（すなわち、改質装置８への都市ガス供給量）と流量制御弁５４の開度（すなわち、リサイクルガス供給量）の関係に基づき、流量制御弁５４の開度を調節することによって、予め設定された所定の供給量になるように制御する。
【０００８】
一方、燃料電池セルスタック２１の酸化剤極２０には、遮断弁６５を開け空気ブロア１５を用いて取り込んだ外気１７を発電用空気１６として供給する。発電用空気１６の供給量は、電圧センサ２２と電流センサ２３で検出した燃料電池出力５０から予め設定された燃料電池出力５０と流量制御弁４６の開度（すなわち、発電用空気供給量）の関係に基づいて、流量制御弁４６の開度を調節し、燃料電池出力５０に見合った値に制御する。燃料電池セルスタック２１の燃料極１８では、（３）式に示す反応により、改質ガス中の水素が水素イオンと電子に変わる。
【０００９】
（燃料極反応）
Ｈ₂ →２Ｈ⁺ ＋２ｅ^- （３）
水素イオンは電解質１９の内部を拡散し、酸化剤極２０に到達する。一方、電子は外部回路を流れ、燃料電池出力５０として取り出される。酸化剤極では、（４）式に示す反応により、燃料極１８から電解質１９の中を拡散してきた水素イオン、燃料極１８から外部回路を通じて移動してきた電子、及び空気中の酸素が三相界面で反応し、水が生成する。
【００１０】
（酸化剤極反応）
２Ｈ⁺ ＋1/2 Ｏ₂ ＋２ｅ^- →Ｈ₂ Ｏ （４）
（３）式と（４）式をまとめると、燃料電池セルスタック２１での全電池反応は、（５）式に示す水素と酸素から水ができる単純な反応として表わすことができる。
【００１１】
（電池反応）
Ｈ₂ ＋1/2 Ｏ₂ →Ｈ₂ Ｏ （５）
発電によって得られた燃料電池出力５０は、変換装置２４で電圧変換あるいは直流−交流変換が行われた後に、負荷２５に供給される。燃料極１８では、改質ガス中の水素がすべて（３）式に示した電極反応で消費されるわけではなく、全体の８０％程度の水素が使われるだけである。残りの約２０％の水素が、未反応水素として燃料極排ガス中に残存する。これは、燃料極１８で改質ガス中の水素をすべて電極反応で消費しようとすると、ガス出口付近で局所的に水素が不足し、水素の代わりに燃料極基板のカーボンが反応し燃料電池セルスタック２１が劣化するためである。未反応水素を含む燃料極排ガス１３は、改質装置バーナ９に供給され、バーナ燃料として使用される。（１）式に示したメタンの水蒸気改質反応は吸熱反応であるので、外部から反応熱に見合う熱を改質装置８の改質部４８に与える必要がある。このため、改質装置バーナ９で燃料極排ガス１３中の水素を遮断弁６２を開けて空気ブロア１５により供給した燃焼用空気１２とともに燃焼させることにより、改質装置８の改質部の温度を最大７００℃程度まで昇温する。燃焼用空気１２の供給量は、温度センサ４１で検出した改質装置温度から予め設定された改質装置温度と流量制御弁４５の開度（すなわち、燃焼用空気供給量）の関係に基づいて、流量制御弁４５の開度を調節することによって制御する。
【００１２】
また、燃料極排ガス１３中の未反応水素の燃焼反応により生成した水蒸気と未反応水蒸気を含む改質装置バーナ燃焼排ガス１４と（５）式に示した電池反応により生成した水蒸気を含む酸化剤極排ガス３７は凝縮器３８に送られ、水蒸気が凝縮水４０として除去された後に、排ガス３９として大気中に放出される。凝縮水４０は、気水分離器２７に戻され、電池冷却水２６、改質用水蒸気３１、排熱回収用水蒸気３４等に利用される。
【００１３】
（５）式に示した電池反応は発熱反応であるので、燃料電池セルスタック２１の温度は、発電時間の経過とともに上昇する。燃料電池セルスタック２１の温度上昇が起こると、電解質の水素イオン伝導率が上がるために抵抗が減少し出力特性が一時的に向上するが、劣化が起こり易くなり寿命低下が生じる。そこで、気水分離器２７から電池冷却水２６を冷却器６３に供給し、燃料電池セルスタック２１の冷却を行う。燃料電池セルスタック２１の作動温度は、寿命と性能の両方を勘案して１９０℃前後に設定されるのが一般的である。電池冷却水２６の供給量は、温度センサ６４で検出した電池冷却水セルスタック出口温度が予め設定された所定の温度範囲となるように、流量制御弁３０の開度を調節することによって制御する。燃料電池セルスタック２１を出た電池冷却水２６は、水と水蒸気の混合物の形で気水分離器２７に戻される。起動時及び圧力センサ４９で気水分離器圧力が予め設定された所定の圧力より低下したことを検出した場合には、予め設定された所定の電力を圧力センサ４９で気水分離器圧力が予め設定された所定の圧力を越えたことを検出するまで気水分離器ヒータ２８に供給し、水蒸気を発生させる。また、液面センサ５５で気水分離器２７の水位が予め設定された所定の水位よりも低下したことを検出した場合には、液面センサ５５で気水分離器２７の水位が予め設定された所定の水位になったことを検出するまで、補給水ポンプ４３を動作させて気水分離器２７に補給水４４を供給する。燃料電池セルスタック２１から気水分離器２７に供給された水蒸気あるいは気水分離器２７で発生させた水蒸気のうち、改質用水蒸気３１として使用する以外の水蒸気は、排熱回収用水蒸気３４として蒸発器３３に供給し、排熱利用システム３５の冷媒３６の蒸発に使われる。蒸発器３３で凝縮した排熱回収用水蒸気３４の凝縮水５８は、気水分離器２７に戻される。
【００１４】
次に、この従来の燃料電池発電装置の問題点について説明する。従来の燃料電池発電装置では、改質装置の劣化状態を診断するためには、改質装置出口にガスクロマトグラフ等の高価なガス分析装置を接続して連続的に改質装置出口ガス （改質ガス）をサンプリングしガス分析を行う、あるいは、定期的に容器に改質装置出口ガス（改質ガス）をサンプリングしガス分析装置のあるところまでもっていってガス分析を行うことによって、改質装置出口ガス（改質ガス）中のメタン量（メタンスリップ量）の増加から改質装置の劣化状態を診断し、改質触媒の取替時期を判定していた。参考のために、２００ｋＷリン酸型燃料電池発電装置を用いて、都市ガスを燃料として２００ｋＷ定格出力での発電を行った場合の、改質装置出口ガス（改質ガス）中のメタン量（メタンスリップ量）と改質装置の改質触媒の劣化量の関係を図９に示す。改質装置出口ガス（改質ガス）中のメタン量（メタンスリップ量）を検出することにより改質触媒の劣化量、すなわち改質装置８の改質部４８の劣化状態の診断が可能であり、得られた改質触媒の劣化量と発電時間の関係から劣化速度を求め、改質触媒の全充填量で決まる改質装置性能の低下を引き起こさない改質触媒の劣化量の最大許容値に至るまでの期間を計算することによって改質触媒の取替時期を判定することができる。しかし、これらの方法では、ガス分析に時間がかかりその場で瞬時に改質装置の劣化状態の診断ができない、改質装置の劣化診断のために高価なガス分析装置が必要である、その場で連続的に改質装置の劣化状態を診断するためには燃料電池発電装置に対して専用のガス分析装置が必要である、ガス分析装置のあるところまでサンプリングガスをもっていかなければならないので時間がかかる等の問題点があった。
【００１５】
【発明が解決しようとする課題】
本発明の目的は、改質ガスのサンプリングと分析に長時間を要し改質装置の劣化診断を瞬時に行うことができない、改質装置の劣化診断のために高価なガス分析装置が必要である、改質装置の劣化診断をその場で連続的に行おうとすると燃料電池発電装置に対して専用のガス分析装置が必要である等の問題点を解決した、その場で瞬時に且つ連続的に改質装置の劣化診断を行い改質触媒の取替時期を判定することが可能な燃料電池発電装置とその改質装置の劣化診断方法を提供することにある。
【００１６】
【課題を解決するための手段】
上記目的を達成するために本発明は、改質装置バーナ燃焼ガス温度、改質装置バーナ燃焼排ガス温度、改質装置出口ガス温度（改質ガス温度）のいずれか一つ、あるいは一つ以上を検出し、改質装置の劣化状態の診断を行うことを最も主要な特徴とする。従来の技術とは、改質装置バーナ燃焼ガス温度測定用温度センサ、改質装置バーナ燃焼排ガス温度測定用温度センサ、改質装置出口ガス温度（改質ガス温度）測定用温度センサを１個以上設置し、検出した温度を信号に変換して劣化診断部に送信し、劣化診断部で検出した温度を予め記憶された検出した温度（改質装置バーナ燃焼ガス温度、改質装置バーナ燃焼排ガス温度、改質装置出口ガス温度（改質ガス温度）のいずれか一つ、あるいは一つ以上）と改質装置の改質触媒の劣化量の関係に照合することによって、ガスクロマトグラフ等の高価なガス分析装置を用いて長時間を要する改質装置出口ガス（改質ガス）の分析作業を行うことなしに、その場で瞬時に改質装置の劣化状態を診断し、改質触媒の取替時期を判定することを可能にしたという点が異なる。
【００１７】
【発明の実施の形態】
以下図面を参照して本発明の実施の形態例を詳細に説明する。
図１に本発明の一実施形態例を表す構成図を示す。図２と同一のものは同一符号で表し、これらのものについてはその説明を省略する。また、本発明の詳細を説明する改質装置の拡大図を図３に示す。図３において、２９は触媒充填層、４２は改質管である。
【００１８】
図１及び図３を用いて本発明の一実施形態例を説明する。本実施形態例は図２に示した従来例とは、図１及び図３に示したように改質装置８に触媒充填層温度測定用温度センサ６、改質管外壁温度測定用温度センサ３２、改質装置バーナ燃焼ガス温度測定用温度センサ１０、改質装置バーナ燃焼排ガス温度測定用温度センサ４７、改質装置出口ガス温度（改質ガス温度）測定用温度センサ５１を１個以上新たに設けた点と、温度センサで検出した改質装置の触媒充填層温度、改質管外壁温度、改質装置バーナ燃焼ガス温度、改質装置バーナ燃焼排ガス温度、改質装置出口ガス温度（改質ガス温度）のいずれか一つ、あるいは一つ以上の信号を受け、予め記憶された改質装置触媒充填層温度と改質装置の改質触媒の劣化量の関係、改質装置改質管外壁温度と改質装置の改質触媒の劣化量の関係、改質装置バーナ燃焼ガス温度と改質装置の改質触媒の劣化量の関係、改質装置バーナ燃焼排ガス温度と改質装置の改質触媒の劣化量の関係、改質装置出口ガス温度（改質ガス温度）と改質装置の改質触媒の劣化量の関係のいずれか一つ、あるいは一つ以上と照合することによって改質装置８の劣化状態を診断する劣化診断部５を新たに設けた点が異なる。
【００１９】
次に本実施形態例の作用について説明する。本実施形態例では、改質装置８の改質部４８に設けた１個以上の触媒充填層温度測定用温度センサ６、改質管外壁温度測定用温度センサ３２、改質装置バーナ燃焼ガス温度測定用温度センサ１０、改質装置バーナ燃焼排ガス温度測定用温度センサ４７、改質装置出口ガス温度（改質ガス温度）測定用温度センサ５１で、改質装置の触媒充填層温度、改質管外壁温度、改質装置バーナ燃焼ガス温度、改質装置バーナ燃焼排ガス温度、改質装置出口ガス温度（改質ガス温度）のいずれか一つ、あるいは一つ以上を検出し、これらの温度検出信号を劣化診断部５に送信して、温度検出信号を受信した劣化診断部５で、予め記憶された検出温度と改質装置の改質触媒の劣化量の関係、すなわち、改質装置触媒充填層温度と改質装置の改質触媒の劣化量の関係、改質装置改質管外壁温度と改質装置の改質触媒の劣化量の関係、改質装置バーナ燃焼ガス温度と改質装置の改質触媒の劣化量の関係、改質装置バーナ燃焼排ガス温度と改質装置の改質触媒の劣化量の関係、改質装置出口ガス温度（改質ガス温度）と改質装置の改質触媒の劣化量の関係のうちいずれか一つ、あるいは一つ以上と照合することによって改質触媒の劣化量、すなわち改質装置８の改質部４８の劣化状態を診断することが従来技術とは異なる。
【００２０】
２００ｋＷリン酸型燃料電池発電装置を用いて、都市ガスを燃料として２００ｋＷ定格出力での発電を行った場合の、触媒充填層（Ｎｉ−Ａｌ₂ Ｏ₃ 触媒とＲｕ−Ａｌ₂ Ｏ₃ 触媒の二層構造触媒充填層を採用、以下同じ）の原燃料ガス入口、触媒充填層の全長の２０％の位置（原燃料ガス入口から換算、以下同じ）、触媒充填層の全長の４０％の位置、触媒充填層の全長の６０％の位置、及び触媒充填層の改質ガス出口の五カ所の改質装置触媒充填層温度と改質装置の改質触媒の劣化量の関係を図４に示す。図４から改質触媒の劣化量の増加とともに、改質装置触媒充填層温度は変化することがわかる。従って、改質装置触媒充填層温度を１カ所以上検出することにより改質触媒の劣化量、すなわち改質装置８の改質部４８の劣化状態の診断が可能であり、得られた改質触媒の劣化量と発電時間の関係から劣化速度を求め、改質触媒の全充填量で決まる改質装置性能の低下を引き起こさない改質触媒の劣化量の最大許容値に至るまでの期間を計算することによって改質触媒の取替時期を判定することができる。なお、改質装置内に２本以上改質管が設置され、２カ所以上触媒充填層がある場合には、各触媒充填層毎に触媒充填層温度を検出することにより、各改質管毎の改質触媒の劣化量、すなわち各改質管毎の劣化状態の診断が可能であり、得られた改質触媒の劣化量と発電時間の関係から劣化速度を求め、改質管毎の改質触媒の充填量で決まる改質管性能の低下を引き起こさない改質触媒の劣化量の最大許容値に至るまでの期間を計算することによって改質管毎に改質触媒の取替時期を判定することができる。同様に、２００ｋＷリン酸型燃料電池発電装置を用いて、都市ガスを燃料として２００ｋＷ定格出力での発電を行った場合の、触媒充填層の原燃料ガス入口、触媒充填層の全長の２０％の位置（原燃料ガス入口から換算、以下同じ）、触媒充填層の全長の４０％の位置、触媒充填層の全長の６０％の位置、及び触媒充填層の改質ガス出口の五カ所の改質装置改質管外壁温度と改質装置の改質触媒の劣化量の関係を図５に示す。図５から改質触媒の劣化量の増加とともに、改質装置改質管外壁温度は変化することがわかる。従って、改質装置改質管外壁温度を１カ所以上検出することにより改質触媒の劣化量、すなわち改質装置８の改質部４８の劣化状態の診断が可能であり、得られた改質触媒の劣化量と発電時間の関係から劣化速度を求め、改質触媒の全充填量で決まる改質装置性能の低下を引き起こさない改質触媒の劣化量の最大許容値に至るまでの期間を計算することによって改質触媒の取替時期を判定することができる。なお、改質装置内に２本以上改質管が設置され、２カ所以上触媒充填層がある場合には、各触媒充填層毎に触媒充填層温度を検出することにより、各改質管毎の改質触媒の劣化量、すなわち各改質管毎の劣化状態の診断が可能であり、得られた改質触媒の劣化量と発電時間の関係から劣化速度を求め、各改質管毎の改質触媒の充填量で決まる改質管性能の低下を引き起こさない改質触媒の劣化量の最大許容値に至るまでの期間を計算することによって各改質管毎の改質触媒の取替時期を判定することができる。また、２００ｋＷリン酸型燃料電池発電装置を用いて、都市ガスを燃料として２００ｋＷ定格出力での発電を行った場合の、改質装置バーナ燃焼ガス温度と改質装置の改質触媒の劣化量の関係を図６に示す。図６から改質触媒の劣化量の増加とともに、改質装置バーナ燃焼ガス温度は上昇することがわかる。従って、改質装置バーナ燃焼ガス温度を検出することにより改質触媒の劣化量、すなわち改質装置８の改質部４８の劣化状態の診断が可能であり、得られた改質触媒の劣化量と発電時間の関係から劣化速度を求め、改質触媒の全充填量で決まる改質装置性能の低下を引き起こさない改質触媒の劣化量の最大許容値に至るまでの期間を計算することによって改質触媒の取替時期を判定することができる。なお、改質装置バーナ燃焼ガス温度は２カ所以上で検出し平均値をとってもよい。さらに、２００ｋＷリン酸型燃料電池発電装置を用いて、都市ガスを燃料として２００ｋＷ定格出力での発電を行った場合の、改質装置バーナ燃焼排ガス温度と改質装置の改質触媒の劣化量の関係を図７に示す。図７から改質触媒の劣化量の増加とともに、改質装置バーナ燃焼排ガス温度は上昇することがわかる。従って、改質装置バーナ燃焼排ガス温度を検出することにより改質触媒の劣化量、すなわち改質装置８の改質部４８の劣化状態の診断が可能であり、得られた改質触媒の劣化量と発電時間の関係から劣化速度を求め、改質触媒の全充填量で決まる改質装置性能の低下を引き起こさない改質触媒の劣化量の最大許容値に至るまでの期間を計算することによって改質触媒の取替時期を判定することができる。なお、改質装置バーナ燃焼排ガス温度は２カ所以上で検出し平均値をとってもよい。最後に、２００ｋＷリン酸型燃料電池発電装置を用いて、都市ガスを燃料として２００ｋＷ定格出力での発電を行った場合の、改質装置出口ガス温度（改質ガス温度）と改質装置の改質触媒の劣化量の関係を図８に示す。図８から改質触媒の劣化量の増加とともに、改質装置出口ガス温度（改質ガス温度）は上昇することがわかる。従って、改質装置出口ガス温度（改質ガス温度）を検出することにより改質触媒の劣化量、すなわち改質装置８の改質部４８の劣化状態の診断が可能であり、得られた改質触媒の劣化量と発電時間の関係から劣化速度を求め、改質触媒の全充填量で決まる改質装置性能の低下を引き起こさない改質触媒の劣化量の最大許容値に至るまでの期間を計算することによって改質触媒の取替時期を判定することができる。なお、改質装置出口ガス温度（改質ガス温度）は２カ所以上検出し平均値をとってもよい。
【００２１】
【発明の効果】
以上述べたように本発明によれば、改質装置に触媒充填層温度測定用温度センサ、改質管外壁温度測定用温度センサ、改質装置バーナ燃焼ガス温度測定用温度センサ、改質装置バーナ燃焼排ガス温度測定用温度センサ、改質装置出口ガス温度（改質ガス温度）測定用温度センサを１個以上設置し、検出した改質装置の触媒充填層温度、改質管外壁温度、改質装置バーナ燃焼ガス温度、改質装置バーナ燃焼排ガス温度、改質装置出口ガス温度（改質ガス温度）のいずれか一つ、あるいは一つ以上を信号に変換して劣化診断部に送信し、劣化診断部で検出した温度を予め記憶された改質装置の触媒充填層温度、改質管外壁温度、改質装置バーナ燃焼ガス温度、改質装置バーナ燃焼排ガス温度、改質装置出口ガス温度（改質ガス温度）のいずれか一つ、あるいは一つ以上と改質装置の改質触媒の劣化量の関係に照合することによって改質装置の劣化状態を診断し、改質触媒の取替時期を判定するので、改質装置の劣化状態の診断のためのガスクロマトグラフ等の高価なガス分析装置を用いた長時間を要する改質装置出口ガス（改質ガス）の分析作業が不要である、その場で瞬時に且つ連続的に改質装置の劣化状態の診断が可能である、改質触媒の劣化状態を常に把握し改質触媒の取替時期を前もって知ることができるので改質装置性能の低下が起こる前に改質触媒の取替が可能であるという効果がある。
【図面の簡単な説明】
【図１】本発明の一実施形態例を示す構成説明図である。
【図２】従来の燃料電池発電装置を示す構成説明図である。
【図３】本発明に係る改質装置の一例を示す拡大図である。
【図４】本発明に係る改質装置触媒充填層温度と改質装置の改質触媒の劣化量の関係の一例を示す特性図である。
【図５】本発明に係る改質装置改質管外壁温度と改質装置の改質触媒の劣化量の関係の一例を示す特性図である。
【図６】本発明に係る改質装置バーナ燃焼ガス温度と改質装置の改質触媒の劣化量の関係の一例を示す特性図である。
【図７】本発明に係る改質装置バーナ燃焼排ガス温度と改質装置の改質触媒の劣化量の関係の一例を示す特性図である。
【図８】本発明に係る改質装置出口ガス温度と改質装置の改質触媒の劣化量の関係の一例を示す特性図である。
【図９】従来の改質装置出口ガス（改質ガス）中のメタン量（メタンスリップ量）の関係の一例を示す特性図である。
【符号の説明】
１…原燃料ガス、２…改質装置出口ガス（改質ガス）、３…遮断弁、４…都市ガス、５…劣化診断部、６…触媒充填層温度測定用温度センサ、７…脱硫装置、８…改質装置、９…改質装置バーナ、１０…改質装置バーナ燃焼ガス温度測定用温度センサ、１１…シフトコンバータ、１２…燃焼用空気、１３…燃料極排ガス、１４…改質装置バーナ燃焼排ガス、１５…空気ブロア、１６…発電用空気、１７…外気、１８…燃料極、１９…電解質、２０…酸化剤極、２１…燃料電池セルスタック、２２…電圧センサ、２３…電流センサ、２４…変換装置、２５…負荷、２６…電池冷却水、２７…気水分離器、２８…気水分離器ヒータ、２９…触媒充填層、３０…流量制御弁、３１…改質用水蒸気、３２…改質管外壁温度測定用温度センサ、３３…蒸発器、３４…排熱回収用水蒸気、３５…排熱利用システム、３６…冷媒、３７…酸化剤極排ガス、３８…凝縮器、３９…排ガス、４０…凝縮水、４１…温度センサ、４２…改質管、４３…補給水ポンプ、４４…補給水、４５…流量制御弁、４６…流量制御弁、４７…改質装置バーナ燃焼排ガス温度測定用温度センサ、４８…改質部、４９…圧力センサ、５０…燃料電池出力、５１…改質装置出口ガス温度（改質ガス温度）測定用温度センサ、５２…流量制御弁、５３…エジェクタ、５４…流量制御弁、５５…液面センサ、５６…ポンプ、５７…遮断弁、５８…凝縮水、５９…起動用バーナ、６０…遮断弁、６１…改質装置起動用バーナ空気、６２…遮断弁、６３…冷却器、６４…温度センサ、６５…遮断弁。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel cell power generation apparatus that generates hydrogen by reacting fuel and water vapor in a reformer and reacting this oxygen with oxygen in a cell stack and a deterioration diagnosis method for the reformer. Fuel capable of diagnosing the degradation state of the reformer instantaneously and continuously on the spot and determining the replacement timing of the reforming catalyst without analyzing the outlet gas (reformed gas) The present invention relates to a battery power generation apparatus and a deterioration diagnosis method for the reforming apparatus.
[0002]
[Prior art]
FIG. 2 shows a configuration of a phosphoric acid fuel cell power generation device using city gas as a fuel as a conventional example of a fuel cell power generation device. In the figure, 1 is a raw fuel gas, 2 is a reformer outlet gas (reformed gas), 3 is a shut-off valve, 4 is a city gas, 7 is a desulfurizer, 8 is a reformer, 9 is a reformer burner, 11 is a shift converter, 12 is combustion air, 13 is fuel electrode exhaust gas, 14 is reformer burner combustion exhaust gas, 15 is an air blower, 16 is air for power generation, 17 is outside air, 18 is fuel electrode, 19 is electrolyte, 20 is an oxidizer electrode, 21 is a fuel cell stack, 22 is a voltage sensor, 23 is a current sensor, 24 is a conversion device, 25 is a load, 26 is battery cooling water, 27 is an air / water separator, and 28 is air / water separation. Heater, 30 is a flow control valve, 31 is steam for reforming, 33 is an evaporator, 34 is steam for exhaust heat recovery, 35 is exhaust heat utilization system, 36 is refrigerant, 37 is oxidant electrode exhaust gas, 38 is condensed 39, exhaust gas, 40 condensed water, 41 temperature sensor 43 is a makeup water pump, 44 is makeup water, 45 is a flow control valve, 46 is a flow control valve, 48 is a reforming unit, 49 is a pressure sensor, 50 is a fuel cell output, 52 is a flow control valve, 53 is an ejector, 54 is a flow control valve, 55 is a liquid level sensor, 56 is a pump, 57 is a shutoff valve, 58 is condensed water, 59 is a start burner, 60 is a shutoff valve, 61 is reformer starter burner air, and 62 is shut off. A valve, 63 is a cooler, 64 is a temperature sensor, and 65 is a shut-off valve.
[0003]
The operation of this conventional fuel cell power generator will be described below with reference to FIG. The shut-off valve 3 is opened, and the city gas 4 is supplied to a desulfurization device 7 filled with a desulfurization catalyst (cobalt-molybdenum catalyst and zinc oxide adsorbent), and the desulfurization device 7 uses the reformer 8 and the fuel cell stack 21. The sulfur content contained in the odorant in the city gas 4 that causes deterioration of the catalyst of the fuel electrode 18 is removed by adsorption. The shut-off valve 57 is opened only when the fuel cell power generator is activated, and the city gas 4 is supplied to the activation burner 59. The shut-off valve 60 is also opened only when the fuel cell power generator is activated, and the activation burner air 61 is supplied to the activation burner 59 by the air blower 15. In the start burner 59, the city gas 4 is combusted when the fuel cell power generator is started, and the temperature of the reformer 8 is increased. The shut-off valve 57 and the shut-off valve 60 are closed except during startup. The city gas supply amount is determined in advance from the fuel cell output 50 detected by the voltage sensor 22 and the current sensor 23 and the reformer temperature detected by the temperature sensor 41. The city gas supply amount is set to a value commensurate with the fuel cell output 50 and the reformer temperature by adjusting the opening degree of the flow control valve 52 based on the relationship of the opening degree (ie, the city gas supply amount). To do. The city gas 4 from which the sulfur content has been adsorbed and removed by the desulfurization device 7 is mixed with the reforming steam 31 supplied from the steam separator 27 by the ejector 53 and filled with a reforming catalyst (usually a nickel catalyst). Is supplied to the reforming section 48 of the reformer 8. The reforming steam supply amount to the ejector 53 is determined based on the opening degree of the flow rate control valve 52 (that is, the city gas supply amount to the reformer 8) and the opening degree of the ejector 53 (that is, the reforming supply amount). By controlling the opening degree of the ejector 53 based on the relationship of the (water vapor supply amount), control is performed so that a predetermined steam carbon ratio is set in advance. In the reformer 8, steam reforming of the city gas 4 that is a fuel gas is performed, and a hydrogen-rich reformed gas is produced. The steam reforming reaction of methane, the main component of city gas, is expressed by the following equation.
[0004]
[Expression 1]

[0005]
Since this hydrogen-rich reformed gas contains carbon monoxide that causes deterioration of the catalyst of the fuel electrode 18 of the fuel cell stack 21, the reformed gas is a shift catalyst (copper-zinc catalyst). The carbon monoxide in the reformed gas is converted into carbon dioxide by the shift reaction shown in the following equation.
[0006]
[Expression 2]

[0007]
The shift converter 11 reduces the carbon monoxide concentration in the reformed gas to 1% or less. The reformed gas exiting the shift converter 11 is supplied to the fuel electrode 18 of the fuel cell stack 21 and used for power generation of the fuel cell. A part of the shift converter outlet gas is recycled to the desulfurization unit 7, and hydrogen in the recycle gas is used for the desulfurization reaction. The supply amount of the recycle gas is a relationship between a preset opening degree of the flow control valve 52 (that is, a city gas supply amount to the reformer 8) and an opening degree of the flow control valve 54 (ie, a recycle gas supply amount). Based on the above, by adjusting the opening degree of the flow control valve 54, it is controlled so as to become a predetermined supply amount set in advance.
[0008]
On the other hand, the outside air 17 taken in using the air blower 15 is supplied to the oxidant electrode 20 of the fuel cell stack 21 as the power generation air 16 by opening the shut-off valve 65. The supply amount of the power generation air 16 is determined from the fuel cell output 50 detected by the voltage sensor 22 and the current sensor 23 and the opening degree of the fuel cell output 50 and the flow rate control valve 46 (that is, the generation air supply amount). Based on the relationship, the opening degree of the flow control valve 46 is adjusted and controlled to a value commensurate with the fuel cell output 50. In the fuel electrode 18 of the fuel cell stack 21, hydrogen in the reformed gas is changed into hydrogen ions and electrons by the reaction shown in the equation (3).
[0009]
(Fuel electrode reaction)
H ₂ → 2H ⁺ + 2e ^- (3)
The hydrogen ions diffuse inside the electrolyte 19 and reach the oxidizer electrode 20. On the other hand, electrons flow through an external circuit and are taken out as a fuel cell output 50. In the oxidizer electrode, hydrogen ions diffused from the fuel electrode 18 through the electrolyte 19, electrons moved from the fuel electrode 18 through an external circuit, and oxygen in the air by the reaction shown in the equation (4) are three-phase interfaces. To produce water.
[0010]
(Oxidant electrode reaction)
2H ⁺ +1/2 O ₂ + 2e ^- → H ₂ O (4)
Summarizing the equations (3) and (4), the total battery reaction in the fuel cell stack 21 can be expressed as a simple reaction in which water is generated from hydrogen and oxygen shown in the equation (5).
[0011]
(Battery reaction)
H ₂ +1/2 O ₂ → H ₂ O (5)
The fuel cell output 50 obtained by power generation is supplied to the load 25 after voltage conversion or DC-AC conversion is performed by the converter 24. In the fuel electrode 18, not all of the hydrogen in the reformed gas is consumed by the electrode reaction shown in the equation (3), but only about 80% of the total hydrogen is used. The remaining about 20% of hydrogen remains in the anode exhaust gas as unreacted hydrogen. This is because when all the hydrogen in the reformed gas is consumed by the electrode reaction at the fuel electrode 18, hydrogen is locally deficient in the vicinity of the gas outlet, and the carbon on the fuel electrode substrate reacts instead of hydrogen to produce a fuel cell. This is because the stack 21 deteriorates. The fuel electrode exhaust gas 13 containing unreacted hydrogen is supplied to the reformer burner 9 and used as burner fuel. Since the steam reforming reaction of methane shown in the equation (1) is an endothermic reaction, it is necessary to give heat from the outside to the reforming unit 48 of the reforming device 8 corresponding to the reaction heat. For this reason, the reformer burner 9 burns the hydrogen in the fuel electrode exhaust gas 13 together with the combustion air 12 supplied by the air blower 15 by opening the shut-off valve 62, so that the temperature of the reforming section of the reformer 8 is increased. The temperature is raised to about 700 ° C. The supply amount of the combustion air 12 is based on the relationship between the reformer temperature preset from the reformer temperature detected by the temperature sensor 41 and the opening of the flow control valve 45 (ie, the combustion air supply amount). Control is performed by adjusting the opening degree of the flow control valve 45.
[0012]
Further, the reformer burner combustion exhaust gas 14 containing the steam and unreacted steam generated by the combustion reaction of the unreacted hydrogen in the fuel electrode exhaust gas 13 and the oxidant electrode containing the steam generated by the cell reaction shown in the equation (5). The exhaust gas 37 is sent to the condenser 38, and after the water vapor is removed as the condensed water 40, it is discharged into the atmosphere as the exhaust gas 39. The condensed water 40 is returned to the steam separator 27 and used for the battery cooling water 26, the reforming steam 31, the exhaust heat recovery steam 34, and the like.
[0013]
Since the battery reaction shown in the equation (5) is an exothermic reaction, the temperature of the fuel cell stack 21 increases with the passage of power generation time. When the temperature of the fuel cell stack 21 rises, the hydrogen ion conductivity of the electrolyte increases, so that the resistance decreases and the output characteristics temporarily improve. However, the deterioration tends to occur and the life is shortened. Therefore, the battery cooling water 26 is supplied from the steam separator 27 to the cooler 63 to cool the fuel cell stack 21. The operating temperature of the fuel cell stack 21 is generally set to around 190 ° C. in consideration of both life and performance. The supply amount of the battery cooling water 26 is controlled by adjusting the opening degree of the flow control valve 30 so that the battery cooling water cell stack outlet temperature detected by the temperature sensor 64 falls within a predetermined temperature range set in advance. . Battery cooling water 26 exiting the fuel cell stack 21 is returned to the steam separator 27 in the form of a mixture of water and water vapor. When it is detected at start-up and when the pressure sensor 49 detects that the steam-water separator pressure has fallen below a predetermined pressure, the pressure sensor 49 supplies a predetermined power to the steam-water separator pressure in advance. Steam is generated by supplying the steam to the steam separator heater 28 until it is detected that the predetermined pressure is exceeded. When the liquid level sensor 55 detects that the water level of the steam separator 27 has dropped below a predetermined water level set in advance, the water level of the steam separator 27 is preset by the liquid level sensor 55. The make-up water pump 43 is operated to supply make-up water 44 to the steam separator 27 until it is detected that the predetermined water level has been reached. Among the steam supplied from the fuel cell stack 21 to the steam separator 27 or the steam generated by the steam separator 27, steam other than that used as the reforming steam 31 is used as the exhaust heat recovery steam 34. It is supplied to the evaporator 33 and used to evaporate the refrigerant 36 of the exhaust heat utilization system 35. The condensed water 58 of the exhaust heat recovery water vapor 34 condensed by the evaporator 33 is returned to the steam separator 27.
[0014]
Next, problems of this conventional fuel cell power generator will be described. In the conventional fuel cell power generator, in order to diagnose the deterioration state of the reformer, an expensive gas analyzer such as a gas chromatograph is connected to the reformer outlet, and the reformer outlet gas (reformer) Gas) and gas analysis, or by periodically sampling the reformer outlet gas (reformed gas) in a container and taking the gas analyzer up to where the gas analyzer is to perform the gas analysis. The deterioration state of the reformer was diagnosed from the increase in the amount of methane (methane slip amount) in the outlet gas (reformed gas), and the replacement timing of the reforming catalyst was determined. For reference, the amount of methane in the reformer outlet gas (reformed gas) when the 200 kW phosphoric acid fuel cell power generator is used to generate power at 200 kW rated power using city gas as fuel (methane) The relationship between the slip amount) and the deterioration amount of the reforming catalyst of the reformer is shown in FIG. By detecting the methane amount (methane slip amount) in the reformer outlet gas (reformed gas), it is possible to diagnose the deterioration amount of the reforming catalyst, that is, the deterioration state of the reforming portion 48 of the reforming device 8. Determine the rate of deterioration from the relationship between the amount of deterioration of the reforming catalyst obtained and the power generation time, and set it to the maximum allowable value of the amount of deterioration of the reforming catalyst that does not cause deterioration of the reformer performance determined by the total charging amount of the reforming catalyst. It is possible to determine the replacement timing of the reforming catalyst by calculating the time period until it is reached. However, in these methods, gas analysis takes time, and it is not possible to diagnose the deterioration state of the reformer instantaneously on the spot, and an expensive gas analyzer is necessary for the deterioration diagnosis of the reformer. In order to continuously diagnose the deterioration state of the reformer, a dedicated gas analyzer is required for the fuel cell power generator, and sampling gas must be taken to the point where the gas analyzer is located. There was a problem such as this.
[0015]
[Problems to be solved by the invention]
An object of the present invention is that an expensive gas analyzer is required for the deterioration diagnosis of the reformer, which requires a long time for sampling and analysis of the reformed gas and cannot perform the deterioration diagnosis of the reformer instantaneously. Solved problems such as the necessity of a dedicated gas analyzer for the fuel cell power generator when trying to continuously perform deterioration diagnosis of the reformer on the spot, instantaneously and continuously on the spot Another object of the present invention is to provide a fuel cell power generator capable of performing deterioration diagnosis of a reformer and determining the replacement timing of a reforming catalyst, and a method for diagnosing deterioration of the reformer.
[0016]
[Means for Solving the Problems]
To achieve the above object, the present invention Is Detects one or more of the quality device burner combustion gas temperature, reformer burner combustion exhaust gas temperature, reformer outlet gas temperature (reforming gas temperature), and diagnoses the deterioration state of the reformer The most important feature is to do. With conventional technology Is At least one temperature sensor for measuring the temperature of the gas burner combustion gas, one temperature sensor for measuring the temperature of the reformer burner combustion exhaust gas, and one temperature sensor for measuring the reformer outlet gas temperature (reformed gas temperature), and detecting the detected temperature The signal is converted into a signal and transmitted to the deterioration diagnosis unit, and the temperature detected by the deterioration diagnosis unit is stored in advance. Degree Of the reformer burner combustion gas temperature, reformer burner combustion exhaust gas temperature, reformer outlet gas temperature (reforming gas temperature), or one or more) and the reforming catalyst reforming amount By checking the relationship, the reformer can be instantly used on the spot without the need to analyze the reformer outlet gas (reformed gas), which requires a long time, using an expensive gas analyzer such as a gas chromatograph. The difference is that it is possible to diagnose the deterioration state of the catalyst and determine the replacement timing of the reforming catalyst.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a block diagram showing an embodiment of the present invention. The same components as those in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted. FIG. 3 shows an enlarged view of the reformer for explaining the details of the present invention. In FIG. 3, 29 is a catalyst packed bed, and 42 is a reforming tube.
[0018]
An embodiment of the present invention will be described with reference to FIGS. This embodiment is different from the conventional example shown in FIG. 2 in that the reformer 8 includes a temperature sensor 6 for measuring the catalyst packed bed temperature and a temperature sensor 32 for measuring the outer wall temperature of the reforming tube as shown in FIGS. One or more temperature sensors 10 for measuring reformer burner combustion gas temperature, temperature sensor 47 for measuring reformer burner combustion exhaust gas temperature, and temperature sensor 51 for measuring reformer outlet gas temperature (reformed gas temperature) are newly added. The reforming device catalyst packed bed temperature, reforming pipe outer wall temperature, reforming device burner combustion gas temperature, reforming device burner combustion exhaust gas temperature, reforming device outlet gas temperature (reforming) Gas temperature), the relationship between the reformer catalyst packed bed temperature stored in advance and the reforming catalyst deterioration amount, the reformer reforming tube outer wall Relationship between temperature and amount of degradation of reforming catalyst of reformer, reformer The relationship between the burner combustion gas temperature and the reforming catalyst reforming amount, the reformer burner combustion exhaust gas temperature and the reforming catalyst degrading amount, the reformer outlet gas temperature (reforming gas temperature) ) And the deterioration amount of the reforming catalyst of the reforming device, a deterioration diagnosis unit 5 for newly diagnosing the deterioration state of the reforming device 8 by comparing with one or more of the relationship is provided. Different.
[0019]
Next, the operation of this embodiment will be described. In the present embodiment, one or more catalyst packed bed temperature measuring temperature sensors 6 provided in the reforming section 48 of the reforming device 8, the temperature sensor 32 for measuring the reforming pipe outer wall temperature, and the reformer burner combustion gas temperature. The temperature sensor 10 for measurement, the temperature sensor 47 for measuring the reformer burner flue gas temperature, and the temperature sensor 51 for measuring the reformer outlet gas temperature (reformed gas temperature), the catalyst packed bed temperature of the reformer, the reformer tube One or more of the outer wall temperature, reformer burner combustion gas temperature, reformer burner combustion exhaust gas temperature, reformer outlet gas temperature (reform gas temperature) are detected, and these temperature detection signals Is transmitted to the deterioration diagnosis unit 5, and the deterioration diagnosis unit 5 that has received the temperature detection signal determines the relationship between the detected temperature stored in advance and the deterioration amount of the reforming catalyst of the reformer, that is, the reformer catalyst packed layer. Temperature and amount of reforming catalyst reforming catalyst Relationship, the reformer reforming pipe outer wall temperature and the reforming catalyst degradation amount, the reformer burner combustion gas temperature and the reforming catalyst degradation amount, the reformer burner combustion One of the relationship between the exhaust gas temperature and the reforming amount of the reforming catalyst of the reforming device, the relationship between the reforming device outlet gas temperature (reforming gas temperature) and the reforming amount of the reforming catalyst of the reforming device, or one It differs from the prior art in diagnosing the deterioration amount of the reforming catalyst, that is, the deterioration state of the reforming unit 48 of the reforming device 8 by collating with one or more.
[0020]
When a 200 kW phosphoric acid fuel cell power generator is used to generate power at 200 kW rated output using city gas as fuel, the catalyst packed bed (Ni-Al ₂ O _Three Catalyst and Ru-Al ₂ O _Three Adopting a two-layer catalyst packed bed of catalyst, the same applies to the raw fuel gas inlet, 20% of the total length of the catalyst packed bed (converted from the raw fuel gas inlet, the same applies hereinafter), 40% of the total length of the catalyst packed bed FIG. 4 shows the relationship between the position of the catalyst, the position of 60% of the total length of the catalyst packed bed, and the reformer catalyst packed bed temperatures at the five reformed gas outlets of the catalyst packed bed and the reforming catalyst deterioration amount. Shown in It can be seen from FIG. 4 that the reformer catalyst packed bed temperature changes as the amount of deterioration of the reforming catalyst increases. Therefore, it is possible to diagnose the deterioration amount of the reforming catalyst, that is, the deterioration state of the reforming section 48 of the reforming device 8 by detecting the reforming device catalyst packed bed temperature at one or more places. The rate of deterioration is calculated from the relationship between the amount of deterioration and the power generation time, and the period until reaching the maximum allowable value of the amount of deterioration of the reforming catalyst that does not cause deterioration of the reformer performance determined by the total charge of the reforming catalyst is calculated. Thus, the replacement timing of the reforming catalyst can be determined. When two or more reforming pipes are installed in the reformer and there are two or more catalyst packed beds, each reforming pipe is detected by detecting the catalyst packed bed temperature for each catalyst packed bed. It is possible to diagnose the amount of degradation of the reforming catalyst, that is, the degradation state of each reforming tube, and obtain the degradation rate from the relationship between the obtained amount of degradation of the reforming catalyst and the power generation time. The time for replacement of the reforming catalyst is determined for each reforming tube by calculating the period until the maximum allowable value of the deterioration amount of the reforming catalyst that does not cause the deterioration of the reforming tube performance determined by the amount of catalyst packed can do. Similarly, when a 200 kW phosphoric acid fuel cell power generator is used to generate power at 200 kW rated output using city gas as fuel, the raw fuel gas inlet of the catalyst packed bed is 20% of the total length of the catalyst packed bed. 5 positions of the reformed gas outlet of the position (converted from the raw fuel gas inlet, the same applies hereinafter), 40% of the total length of the catalyst packed bed, 60% of the total length of the catalyst packed bed FIG. 5 shows the relationship between the outer wall temperature of the apparatus reforming tube and the deterioration amount of the reforming catalyst of the reformer. FIG. 5 shows that the reformer reforming pipe outer wall temperature changes as the amount of deterioration of the reforming catalyst increases. Therefore, it is possible to diagnose the deterioration amount of the reforming catalyst, that is, the deterioration state of the reforming unit 48 of the reforming device 8 by detecting the reformer reforming pipe outer wall temperature at one or more locations, and the obtained reforming can be performed. The rate of deterioration is calculated from the relationship between the amount of catalyst deterioration and the power generation time, and the period until the maximum allowable value of the amount of deterioration of the reforming catalyst that does not cause deterioration of the reformer performance determined by the total charge of the reforming catalyst is calculated. By doing so, it is possible to determine the replacement timing of the reforming catalyst. When two or more reforming pipes are installed in the reformer and there are two or more catalyst packed beds, each reforming pipe is detected by detecting the catalyst packed bed temperature for each catalyst packed bed. It is possible to diagnose the deterioration amount of the reforming catalyst, that is, the deterioration state of each reforming pipe, and obtain the deterioration rate from the relationship between the obtained reforming catalyst deterioration amount and the power generation time. Replacement timing of the reforming catalyst for each reforming tube by calculating the period until the maximum allowable value of the deterioration amount of the reforming catalyst that does not cause deterioration of the reforming tube performance determined by the charging amount of the reforming catalyst Can be determined. In addition, when a 200 kW phosphoric acid fuel cell power generator is used to generate power at 200 kW rated output using city gas as fuel, the reformer burner combustion gas temperature and the reforming catalyst deterioration amount The relationship is shown in FIG. It can be seen from FIG. 6 that the reformer burner combustion gas temperature rises as the amount of deterioration of the reforming catalyst increases. Accordingly, it is possible to diagnose the deterioration amount of the reforming catalyst, that is, the deterioration state of the reforming portion 48 of the reforming device 8 by detecting the reformer burner combustion gas temperature, and the deterioration amount of the obtained reforming catalyst. The rate of deterioration is calculated from the relationship between the power generation time and the power generation time, and is calculated by calculating the period of time until the maximum allowable value of the reforming catalyst deterioration amount that does not cause a reduction in the reformer performance determined by the total charging amount of the reforming catalyst. The replacement timing of the quality catalyst can be determined. The reformer burner combustion gas temperature may be detected at two or more locations and averaged. Further, when power is generated at 200 kW rated output using city gas as fuel using a 200 kW phosphoric acid fuel cell power generator, the reformer burner combustion exhaust gas temperature and the reforming catalyst degradation amount The relationship is shown in FIG. It can be seen from FIG. 7 that the reformer burner combustion exhaust gas temperature rises as the amount of deterioration of the reforming catalyst increases. Therefore, it is possible to diagnose the deterioration amount of the reforming catalyst, that is, the deterioration state of the reforming portion 48 of the reforming device 8 by detecting the reformer burner combustion exhaust gas temperature, and the deterioration amount of the obtained reforming catalyst. The rate of deterioration is calculated from the relationship between the power generation time and the power generation time, and is calculated by calculating the period of time until the maximum allowable value of the reforming catalyst deterioration amount that does not cause a reduction in the reformer performance determined by the total charging amount of the reforming catalyst. The replacement timing of the quality catalyst can be determined. The reformer burner combustion exhaust gas temperature may be detected at two or more locations and an average value may be taken. Finally, the reformer outlet gas temperature (reformed gas temperature) and the reformer reforming when the 200 kW phosphoric acid fuel cell power generator is used to generate power at 200 kW rated output using city gas as fuel. FIG. 8 shows the relationship of the deterioration amount of the catalyst. It can be seen from FIG. 8 that the reformer outlet gas temperature (reformed gas temperature) increases as the amount of deterioration of the reforming catalyst increases. Therefore, by detecting the reformer outlet gas temperature (reformed gas temperature), it is possible to diagnose the deterioration amount of the reforming catalyst, that is, the deterioration state of the reforming section 48 of the reforming device 8, and the obtained reformation is obtained. Determine the rate of deterioration from the relationship between the amount of degradation of the catalyst and the power generation time, and determine the period until the maximum allowable value of the amount of degradation of the reforming catalyst that does not cause degradation of the reformer performance determined by the total charging amount of the reforming catalyst. By calculating, it is possible to determine the replacement time of the reforming catalyst. It should be noted that the reformer outlet gas temperature (reformed gas temperature) may be detected at two or more locations and averaged.
[0021]
【The invention's effect】
As described above, according to the present invention, the reformer is provided with the temperature sensor for measuring the catalyst packed bed temperature, the temperature sensor for measuring the reformer outer wall temperature, the temperature sensor for measuring the reformer burner combustion gas temperature, and the reformer burner. One or more temperature sensors for measuring the flue gas temperature and one or more temperature sensors for measuring the reformer outlet gas temperature (reformed gas temperature) are installed, and the detected catalyst packed bed temperature, reforming pipe outer wall temperature, reforming Any one or more of equipment burner combustion gas temperature, reformer burner combustion exhaust gas temperature, reformer outlet gas temperature (reforming gas temperature) is converted into a signal and sent to the degradation diagnosis unit for degradation. The temperature detected by the diagnostic unit is stored in advance in the reformer catalyst packed bed temperature, reformer pipe outer wall temperature, reformer burner combustion gas temperature, reformer burner combustion exhaust gas temperature, reformer outlet gas temperature (improved). Quality gas temperature) Or, the deterioration state of the reforming device is diagnosed by checking the relationship between the deterioration amount of one or more and the reforming catalyst of the reforming device, and the replacement time of the reforming catalyst is judged. Analyzing the reformer outlet gas (reformed gas), which requires a long time using an expensive gas analyzer such as a gas chromatograph for diagnosis of the condition, is unnecessary. The deterioration state of the reforming catalyst can be diagnosed, and the deterioration state of the reforming catalyst can always be grasped and the replacement timing of the reforming catalyst can be known in advance. There is an effect that replacement is possible.
[Brief description of the drawings]
FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention.
FIG. 2 is a configuration explanatory view showing a conventional fuel cell power generator.
FIG. 3 is an enlarged view showing an example of a reformer according to the present invention.
FIG. 4 is a characteristic diagram showing an example of the relationship between the reformer catalyst packed bed temperature and the reforming catalyst deterioration amount of the reformer according to the present invention.
FIG. 5 is a characteristic diagram showing an example of the relationship between the reformer reforming tube outer wall temperature and the reforming catalyst deterioration amount according to the present invention.
FIG. 6 is a characteristic diagram showing an example of the relationship between the reformer burner combustion gas temperature and the amount of deterioration of the reforming catalyst of the reformer according to the present invention.
FIG. 7 is a characteristic diagram showing an example of the relationship between the reformer burner combustion exhaust gas temperature and the amount of deterioration of the reforming catalyst of the reformer according to the present invention.
FIG. 8 is a characteristic diagram showing an example of the relationship between the reformer outlet gas temperature and the amount of deterioration of the reforming catalyst of the reformer according to the present invention.
FIG. 9 is a characteristic diagram showing an example of the relationship between the amount of methane (methane slip amount) in the conventional reformer outlet gas (reformed gas).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Raw fuel gas, 2 ... Reformer exit gas (reformed gas), 3 ... Shut-off valve, 4 ... City gas, 5 ... Deterioration diagnostic part, 6 ... Temperature sensor for catalyst packed bed temperature measurement, 7 ... Desulfurization device , 8 ... reformer, 9 ... reformer burner, 10 ... temperature sensor for measuring reformer burner combustion gas temperature, 11 ... shift converter, 12 ... combustion air, 13 ... fuel electrode exhaust gas, 14 ... reformer Burner exhaust gas, 15 ... air blower, 16 ... air for power generation, 17 ... outside air, 18 ... fuel electrode, 19 ... electrolyte, 20 ... oxidant electrode, 21 ... fuel cell stack, 22 ... voltage sensor, 23 ... current sensor , 24 ... Conversion device, 25 ... Load, 26 ... Battery cooling water, 27 ... Air / water separator, 28 ... Air / water separator heater, 29 ... Catalyst packed bed, 30 ... Flow control valve, 31 ... Steam for reforming, 32 ... Temperature sensor for measuring reformer outer wall temperature, 33 ... Steaming 34 ... Steam for exhaust heat recovery, 35 ... Waste heat utilization system, 36 ... Refrigerant, 37 ... Oxidant electrode exhaust gas, 38 ... Condenser, 39 ... Exhaust gas, 40 ... Condensed water, 41 ... Temperature sensor, 42 ... Kai Plumbing pipe 43 ... Supply water pump 44 ... Supply water 45 ... Flow control valve 46 ... Flow control valve 47 ... Temperature sensor for reformer burner combustion exhaust gas temperature measurement 48 ... Reformer 49 ... Pressure sensor 50 ... Fuel cell output, 51 ... Temperature sensor for measuring reformer outlet gas temperature (reformed gas temperature), 52 ... Flow control valve, 53 ... Ejector, 54 ... Flow control valve, 55 ... Liquid level sensor, 56 ... Pump, 57 ... shutoff valve, 58 ... condensate, 59 ... starter burner, 60 ... shutoff valve, 61 ... reformer starter burner air, 62 ... shutoff valve, 63 ... cooler, 64 ... temperature sensor, 65 ... Shut-off valve.

Claims (6)

  A reformer having a reforming tube filled with a reforming catalyst for reacting fuel and steam to produce hydrogen, and an electrolyte for generating electricity by reacting hydrogen produced by the reformer with oxygen In a fuel cell power generation apparatus having a cell stack in which cells comprising a fuel electrode and an oxidant electrode are stacked, a reformer burner combustion gas temperature measuring temperature sensor for measuring a burner combustion gas temperature of the reformer, and the modified The reformer burner combustion gas in which the reformer burner combustion gas temperature detected by the reformer burner combustion gas temperature measurement temperature sensor is received in response to the temperature detection signal from the temperature sensor for measuring the temperature of the combustion burner combustion gas. A deterioration diagnosis unit that diagnoses the deterioration state of the reformer by checking the relationship between the temperature and the deterioration amount of the reforming catalyst of the reformer. Fee cell power plant.   A reformer having a reforming tube filled with a reforming catalyst for reacting fuel and steam to produce hydrogen, and an electrolyte for generating electricity by reacting hydrogen produced by the reformer with oxygen A fuel cell power generation apparatus having a cell stack in which cells comprising a fuel electrode and an oxidant electrode are stacked, a reformer burner combustion exhaust gas temperature measuring temperature sensor for measuring a burner combustion exhaust gas temperature of the reformer, and the modification The reformer burner combustion exhaust gas in which the reformer burner combustion exhaust gas temperature detected by the temperature sensor for measuring the reformer burner combustion exhaust gas temperature in response to the temperature detection signal from the temperature sensor for measuring the temperature of the exhaust gas burner combustion exhaust gas A deterioration diagnosis unit for diagnosing the deterioration state of the reformer by checking the relationship between the temperature and the deterioration amount of the reforming catalyst of the reformer Fuel cell power generation system according to claim.   A reformer having a reforming tube filled with a reforming catalyst for reacting fuel and steam to produce hydrogen, and an electrolyte for generating electricity by reacting hydrogen produced by the reformer with oxygen A fuel cell power generation apparatus having a cell stack in which cells composed of a fuel electrode and an oxidant electrode are stacked, a reformer outlet gas temperature measuring temperature sensor for measuring an outlet gas temperature of the reformer, and the reformer Receiving a temperature detection signal from the temperature sensor for measuring the outlet gas temperature, the temperature detected by the temperature sensor for measuring the reformer outlet gas temperature is stored in advance as the reformer outlet gas temperature stored in advance and the reforming catalyst amount of the reformer. A fuel cell power generator, comprising: a deterioration diagnosing unit that diagnoses a deterioration state of the reformer by checking the relationship.   A reformer having a reforming tube filled with a reforming catalyst for reacting fuel and steam to produce hydrogen, and an electrolyte for generating electricity by reacting hydrogen produced by the reformer with oxygen In the method for diagnosing deterioration of a reformer in a fuel cell power generator having a cell stack in which cells composed of a fuel electrode and an oxidizer electrode are stacked, a step of detecting a burner combustion gas temperature of the reformer, The deterioration state of the reformer is diagnosed by comparing the detected reformer burner combustion gas temperature with a predetermined relationship between the reformer burner combustion gas temperature and the amount of deterioration of the reforming catalyst of the reformer. A deterioration diagnosis method for a reformer of a fuel cell power generator.   A reformer having a reforming tube filled with a reforming catalyst for reacting fuel and steam to produce hydrogen, and an electrolyte for generating electricity by reacting hydrogen produced by the reformer with oxygen In the method for diagnosing deterioration of a reformer in a fuel cell power generator having a cell stack in which cells composed of a fuel electrode and an oxidizer electrode are stacked, a step of detecting a burner combustion exhaust gas temperature of the reformer, The deterioration state of the reformer is diagnosed by comparing the detected reformer burner flue gas temperature with a predetermined relationship between the reformer burner flue gas temperature and the amount of deterioration of the reforming catalyst of the reformer. A deterioration diagnosis method for a reformer of a fuel cell power generator.   A reformer having a reforming tube filled with a reforming catalyst for reacting fuel and steam to produce hydrogen, and an electrolyte for generating electricity by reacting hydrogen produced by the reformer with oxygen In the method for diagnosing deterioration of a reformer in a fuel cell power generation apparatus having a cell stack in which cells composed of a fuel electrode and an oxidizer electrode are stacked, detecting the outlet gas temperature of the reformer, and detecting in this step Diagnosing the deterioration state of the reformer by comparing the reformer outlet gas temperature with a predetermined reformer outlet gas temperature and the relationship between the reforming amount of the reforming catalyst of the reformer and A deterioration diagnosis method for a reformer of a fuel cell power generator, comprising:

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