JP3548041B2 - Fuel cell power generator and method for diagnosing deterioration of reformer - Google Patents

Description

【００１８】
この水素リッチな改質ガスには、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（銅一亜鉛系触媒）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。
【００１９】
（シフト反応）
【００２０】
【数２】

【００２１】
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。
【００２２】
シフトコンバータ１１を出た改質ガスは、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。
【００２３】
また、シフトコンバータ１１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。
【００２４】
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。
【００２５】
一方、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。
【００２６】
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。
【００２７】
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。
【００２８】
（燃料極反応）
【００２９】
【数３】

【００３０】
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。
【００３１】
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。
【００３２】
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、および空気中の酸素が三相界面で反応し、水が生成される。
【００３３】
（酸化剤極反応）
【００３４】
【数４】

【００３５】
（３）式と（４）式をまとめると、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すことができる。
【００３６】
（電池反応）
【００３７】
【数５】

【００３８】
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一交流変換が行われた後に、負荷２５に供給される。
【００３９】
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。
【００４０】
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。
【００４１】
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セルスタック２１が劣化するためである。
【００４２】
未反応水素を含む燃料極排ガス１３は、改質装置バーナ９に俳給され、バーナ撚斜として使用される。
【００４３】
（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、外部から反応熱を改質装置８の改質部４８に与える必要がある。
【００４４】
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４８の温度を最大７００℃程度まで昇温する。
【００４５】
燃焼用空気１２の供給量は、改質装置温度測定用温度センサ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。
【００４６】
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。
【００４７】
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。
【００４８】
（５）式に示した電池反応は発熱反応であるので、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。
【００４９】
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。
【００５０】
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、セルスタック２１の冷却を行う。
【００５１】
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。
【００５２】
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。
【００５３】
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。
【００５４】
起動時および圧カセンサ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カセンサ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。
【００５５】
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。
【００５６】
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に供給され、排熱利用システム３５の冷媒３５の蒸発に使われる。
【００５７】
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。
【００５８】
【発明が解決しようとする課題】
次に、上述したような従来の技術による燃料電池発電装置の問題点について説明する。
【００５９】
すなわち、従来の技術による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ガスをサンプリングしてガス分析を行うか、あるいは、定期的に容器に改質装置出口における改質ガスをサンプリングして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、改質ガス中のメタン量（メタンスリップ量）から改質装置８のメタン転化率を求め、改質装置８の劣化状態を診断するとともに、改質触媒の取替時期を判定していた。
【００６０】
図１０は、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８のメタン転化率と改質装置８の改質触媒の劣化量の関係を示している。
【００６１】
改質装置出口での改質ガス中のメタン量を検出し改質装置８のメタン転化率を計算することによりメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置８の改質部４８の劣化状態の診断が可能であり、得られたメタン転化率あるいは改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、セルスタック２１の発電に悪影響を及ぼさないメタン転化率の下限値、あるいは改質触媒の改質触媒の劣化量の上限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。
【００６２】
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を行うことが不可能であり、また、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となり、さらに、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となり、あるいは、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劣化診断に時間がかかる等の問題点があった。
【００６３】
本発明は、上記の事情に鑑みてなされたもので、その目的とするところは、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不可能であり、また、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となり、さらに、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となり、あるいは、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劣化診断に時間がかかる等の従来の技術によるの燃料電池発電装置の問題点を解決し、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およびその改質装置の劣化診断方法を提供することにある。
【００６６】
【課題を解決するための手段】
本発明の一態様によると、上記課題を解決するための手段として、
燃料と水蒸気を反応させ水素をつくるための改質触媒を充填した改質管を有する改質装置と、
この改質装置でつくられた水素を酸素と反応させて発電を行うための電解質をサンドイッチした燃料極と酸化剤極からなるセルを積層したセルスタックとを有し、
前記燃料極の排ガスを燃焼させることにより前記改質装置の改質部を昇温する燃料電池発電装置において、
前記改質装置のバーナ燃焼排ガスの改質装置出口温度を測定する改質装置バーナ燃焼排ガス改質装置出口温度測定用温度センサと、
この改質装置バーナ燃焼排ガス改質装置出口温度測定用温度センサからの温度検出信号を受け、前記改質装置バーナ燃焼排ガス改質装置出口温度測定用温度センサにより検出された改質装置バーナ燃焼排ガス改質装置出口温度を予め決められた改質装置バーナ燃焼排ガス改質装置出口温度と前記改質装置のメタン転化率の関係の照合データと照合することによって前記改質装置の劣化状態を診断する劣化診断手段と、
を有することを特徴とする燃料電池発電装置が提供される。
【００６７】
また、本発明の別の態様によると、上記課題を解決するための手段として、
燃料と水蒸気を反応させ水素をつくるための改質触媒を充填した改質管を有する改質装置と、
この改質装置でつくられた水素を酸素と反応させて発電を行うための電解質をサンドイッチした燃料極と酸化剤極からなるセルを積層したセルスタックとを有し、
前記燃料極の排ガスを燃焼させることにより前記改質装置の改質部を昇温する燃料電池発電装置において、
改質ガス改質装置出口温度を測定する改質ガス改質装置出口温度測定用温度センサと、
この改質ガス改質装置出口温度測定用温度センサからの温度検出信号を受け、前記改質ガス改質装置出口温度測定用温度センサにより検出した改質ガス改質装置出口温度を予め決められた改質ガス改質装置出口温度と前記改質装置のメタン転化率の関係の照合データと照合することによって前記改質装置の劣化状態を診断する劣化診断手段と、
を有することを特徴とする燃料電池発電装置が提供される。
【００６８】
また、本発明の別の態様によると、上記課題を解決するための手段として、
燃料と水蒸気を反応させ水素をつくるための改質触媒を充填した改質管を有する改質装置と、
この改質装置でつくられた水素を酸素と反応させて発電を行うための電解質をサンドイッチした燃料極と酸化剤極からなるセルを積層したセルスタックとを有し、
前記燃料極の排ガスを燃焼させることにより前記改質装置の改質部を昇温する燃料電池発電装置の改質装置の劣化診断方法において、
前記改質装置のバーナ燃焼排ガス改質装置出口温度を検出するステップと、
検出した改質装置バーナ燃焼排ガス改質装置出口温度を予め決められた改質装置バーナ燃焼排ガス改質装置出口温度と前記改質装置のメタン転化率の関係の照合データと照合することによって前記改質装置の劣化状態を診断するステップと、
を有することを特徴とする燃料電池発電装置の改質装置の劣化診断方法が提供される。
【００６９】
また、本発明の別の態様によると、上記課題を解決するための手段として、
燃料と水蒸気を反応させ水素をつくるための改質触媒を充填した改質管を有する改質装置と、
この改質装置でつくられた水素を酸素と反応させて発電を行うための電解質をサンドイッチした燃料極と酸化剤極からなるセルを積層したセルスタックとを有し、
前記燃料極の排ガスを燃焼させることにより前記改質装置の改質部を昇温する燃料電池発電装置の改質装置の劣化診断方法において、
改質ガス改質装置出口温度を検出するステップと、
検出した改質ガス改質装置出口温度を予め決められた改質ガス改質装置出口温度と前記改質装置のメタン転化率の関係の照合データと照合することによって前記改質装置の劣化状態を診断するステップと、
を有することを特徴とする燃料電池発電装置の改質装置の劣化診断方法が提供される。
【００７０】
【発明の実施の形態】
以下図面を参照して本発明による燃料電池発電装置の実施の形態について説明する。
【００７１】
図１は、本発明による燃料電池発電装置の一実施の形態を表す構成図を示している。
【００７２】
図１において、上述した図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。
【００７３】
図３は、本発明による燃料電池発電装置の詳細を説明する改質装置の拡大図を示している。
【００７４】
図１および図３を用いて本発明による燃料電池発電装置の一実施の形態を説明する。
【００７５】
本実施の形態による燃料電池発電装置は、図２に示した従来の技術による燃料電池発電装置とは、図１および図３に示したように、改質装置８に改質装置触媒充填層温度測定用温度センサ６、改質装置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排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改質装置出口温度測定用温度センサ４７、改質ガス温度測定用温度センサ６６、改質ガス改質装置出口温度測定用温度センサ５１を１個以上新たに設けた点と、改質装置温度測定用温度センサ４１で検出した改質装置温度が信号に変換されて送信され改質装置温度に対応して予め決められた改質装置触媒充填層温度と改質装置８のメタン転化率の関係、改質装置改質管外壁温度と改質装置８のメタン転化率の関係、改質装置バーナ燃焼排ガス温度と改質装置８のメタン転化率の関係、改質装置バーナ燃焼排ガス改質装置出口温度と改質装置８のメタン転化率の関係、改質ガス温度と改質装置８のメタン転化率の関係、改質ガス改質装置出口温度と改質装置８のメタン転化率の関係のいずれか一つ、あるいは一つ以上を照合データとして選択する照合データ選択手段６７、各温度センサ６、３２、１０、４７、６６、５１で検出した改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上の信号を受け、照合データ選択手段６７で、選択され送信された予め決められた改質装置触媒充填層温度と改質装置８のメタン転化率の関係の照合データ、改質装置改質管外壁温度と改質装置８のメタン転化率の関係の照合データ、改質装置バーナ燃焼排ガス温度と改質装置８のメタン転化率の関係の照合データ、改質装置バーナ燃焼排ガス改質装置出口温度と改質装置８のメタン転化率の関係の照合データ、改質ガス温度と改質装置８のメタン転化率の関係の照合データ、改質ガス改質装置出口温度と改質装置８のメタン転化率の関係の照合データのいずれか一つ、あるいは一つ以上と照合することによって改質装置８のメタン転化率あるいはメタン転化率から換算した改質触媒の劣化量を求め、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置８の改質部４８の劣化状態を診断する劣化診断手段５、各温度センサで検出した改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上を、劣化診断手段５において照合データ選択手段６７で選択され送信された予め決められた検出温度（改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上）と改質装置８のメタン転化率の関係の照合データと照合することによって求められ送信されたメタン転化率あるはメタン転化率から換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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寿命診断手段６８を新たに設けた点が異なる。
【００７６】
ここで、照合データ選択手段６７には、予め決められた検出温度（改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上）と改質装置８のメタン転化率の関係の照合データが、後述する図４乃至図９等に基づいて予め作られて保存されているものとする。
【００７７】
また、寿命診断手段６８で、改質触媒の取替時期を判定することができるのは、後述するように、図１０で求めた改質触媒の劣化量を経時的にプロットしておき、、その劣化の時間的傾向から改質触媒の取替時期を推定することができることに基づいており、このように改質触媒の劣化量を経時的にプロットする機能を寿命診断手段６８に持たせているものとする。
【００７８】
そして、劣化診断手段５、照合データ選択手段６７、寿命診断手段６８は、具体的には、パーソナルコンピュータ（ＰＣ）等により、予め所定の記録媒体に記録された劣化診断プログラムに基づいて実行されるものとする。
【００７９】
次に、本実施の形態による燃料電池発電装置の作用について、図１１に示す上記劣化診断プログラムに基づくフローチャートを参照して説明する。
【００８０】
本実施の形態による燃料電池発電装置では、まず、改質装置８の改質部４８に設けた１個以上の改質装置触媒充填層温度測定用温度センサ６、改質装置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排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改質装置出口温度測定用温度センサ４７、改質ガス温度測定用温度センサ６６、改質ガス改質装置出口温度測定用温度センサ５１で、改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上を検出する（ステップＳ１）。
【００８１】
そして、各温度センサから、これらの温度検出信号を劣化診断手段５に送信する（ステップＳ２）。
【００８２】
次に、これらの温度検出信号を受信した劣化診断部５で、改質装置温度測定用温度センサ４１で検出した改質装置温度が信号に変換されて送信された改質装置温度に対応して照合データ選択手段６７で選択され送信された予め決められた検出温度と改質装置８のメタン転化率の関係の照合データ、すなわち、改質装置触媒充填層温度と改質装置８のメタン転化率の関係の照合データ、改質装置改質管外壁温度と改質装置８のメタン転化率の関係の照合データ、改質装置バーナ燃焼排ガス温度と改質装置８のメタン転化率の関係の照合データ、改質装置バーナ燃焼排ガス改質装置出口温度と改質装置８のメタン転化率の関係の照合データ、改質ガス温度と改質装置８のメタン転化率の関係の照合データ、改質ガス改質装置出口温度と改質装置８のメタン転化率の関係の照合データのうちいずれか一つ、あるいは一つ以上と照合する（ステップＳ３）。
【００８３】
これによって、改質装置８のメタン転化率あるいはメタン転化率から換算した改質触媒の劣化量を求め、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置８の改質部４８の劣化状態を診断する（ステップＳ４）。
【００８４】
すなわち、寿命診断手段６８では、各温度センサで検出した改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上を、劣化診断手段５において照合データ選択手段６７で選択され送信された予め決められた検出温度（改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上）と改質装置８のメタン転化率の関係の照合データと照合することによって求めたメタン転化率あるはメタン転化率から換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限値に至るまでの期間を計算する（ステップＳ５）。
【００８５】
そして、これによって求められたメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限値に至るまでの期間に基づいて、改質触媒の取替時期を判定する（ステップＳ６）。
【００８６】
このようにして、本実施の形態による燃料電池発電装置では改質触媒の取替時期を判定することが、従来の技術による燃料電池発電装置とは異なる。
【００８７】
図４は、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８の触媒充填層（Ｎｉ−Ａ１２０３触媒とＲＵ−Ａｌ２０３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、触媒充填層の全長の８０％の位置、及び触媒充填層の改質ガス出口の６カ所の改質装置触媒充填層温度と改質装置８のメタン転化率の関係を示している。
【００８８】
図４から、メタン転化率の減少とともに、改質装置触媒充填層温度は変化することが分かる。
【００８９】
従って、改質装置触媒充填層温度測定用温度センサ６で改質装置触媒充填層温度を検出し、図４に示した改質装置触媒充填層温度と改質装置８のメタン転化率の関係を照合データとして照合することによって改質装置８のメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置８の改質部４８の劣化状態を診断することが可能であり、得られたメタン転化率あるいはメタン転化率から図１０に示した関係を用いて換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、燃料電池の発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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。
【００９０】
なお、改質装置触媒充填層温度測定用温度センサ６を２個以上設置し、検出した温度の平均値を改質装置触媒充填層温度としてもよい。
【００９１】
また、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、各触媒充填層毎に改質装置触媒充填層温度測定用温度センサ６を設置することによって改質装置触媒充填層温度を検出し、図４に示した改質装置触媒充填層温度と改質装置のメタン転化率の関係を照合データとして照合することによって改質管毎のメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から各改質管毎の改質触媒の劣化状態の診断が可能であり、得られたメタン転化率あるいは図１０に示した関係を用いてメタン転化率から換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、改質管毎に燃料電池の発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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。
【００９２】
図５は、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、改質装置８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、触媒充填層の全長の８０％の位置、及び触媒充填層の改質ガス出口の６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示している。
【００９３】
図５から、メタン転化率の低下とともに、改質装置改質管外壁温度は変化することが分かる。
【００９４】
従って、改質装置改質管外壁温度測定用温度センサ３２で改質装置改質管外壁温度を検出し、図５に示した改質装置改質管外壁温度と改質装置８のメタン転化率の関係を照合データとして照合することによって改質装置８のメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置８の改質部４８の劣化状態の診断が可能であり、得られたメタン転化率あるいはメタン転化率から図１０に示した関係を用いて換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、燃料電池の発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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。
【００９５】
なお、改質装置改質管外壁温度測定用温度センサ３２を２個以上設置し、検出した温度の平均値を改質装置改質管外壁温度としてもよい。
【００９６】
また、改質装置内に２本以上改質管が設置されている場合には、各触媒充填層毎に改質装置改質管外壁温度測定用温度センサ３２を設置することによって改質装置改質管外壁温度を検出し、図５に示した改質装置改質管外壁温度と改質装置８のメタン転化率の関係を照合データとして照合することによって各改質管毎のメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から各改質管毎の改質触媒の劣化状態の診断が可能であり、得られたメタン転化率あるいはメタン転化率から図１０に示した関係を用いて換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、改質管毎に燃料電池の発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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。
【００９７】
図６は、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８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、触媒充填層の全長の８０％の位置、及ぴ触媒充填層の改質ガス出口の６カ所の改質装置バーナ燃焼排ガス温度と改質装置８のメタン転化率の関係を示している。
【００９８】
図６から、メタン転化率の低下とともに、改質装置バーナ燃焼排ガス温度は変化することが分かる。
【００９９】
従って、改質装置バーナ燃焼排ガス温度測定用温度センサ１０で改質装置バーナ燃焼排ガス温度を検出し、図６に示した改質装置バーナ燃焼排ガス温度と改質装置８のメタン転化率の関係を照合データとして照合することによって改質装置８のメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置８の改質部４８の劣化状態の診断が可能であり、得られたメタン転化率あるいはメタン転化率から図１０に示した関係を用いて換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、燃料電池の発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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。
【０１００】
なお、改質装置バーナ燃焼排ガス温度測定用温度センサ１０を２個以上設置し、検出した温度の平均値を改質装置バーナ燃焼排ガス温度としてもよい。
【０１０１】
図７は、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改質装置出口温度と改質装置８のメタン転化率の関係を示している。
【０１０２】
図７から、メタン転化率の低下とともに、改質装置バーナ燃焼排ガス改質装置出口温度は上昇することが分かる。
【０１０３】
従って、改質装置バーナ燃焼排ガス改質装置出口温度測定用温度センサ４７を設置することによって改質装置バーナ燃焼排ガス改質装置出口温度を検出し、図７に示した改質装置バーナ燃焼排ガス改質装置出口温度と改質装置８のメタン転化率の関係を照合データとして照合することによって改質装置８のメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置８の改質部４８の劣化状態の診断が可能であり、得られたメタン転化率あるいはメタン転化率から図１０に示した関係を用いて換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、燃料電池の発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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。
【０１０４】
なお、改質装置バーナ燃焼排ガス改質装置出口温度測定用温度センサ４７を２個以上設置し、検出した温度の平均値を改質装置バーナ燃焼排ガス改質装置出口温度としてもよい。
【０１０５】
図８は、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８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、触媒充填層の全長の８０％の位置、及ぴ触媒充填層の改質ガス出口の６カ所の改質ガス温度と改質装置８のメタン転化率の関係を示している。
【０１０６】
図８から、メタン転化率の低下とともに、改質ガス温度は変化することが分かる。
【０１０７】
従って、改質ガス温度測定用温度センサ６６で改質ガス温度を検出し、図８に示した改質ガス温度と改質装置８のメタン転化率の関係を照合データとして照合することによって改質装置８のメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置８の改質部４８の劣化状態の診断が可能であり、得られたメタン転化率あるいはメタン転化率から図１０に示した関係を用いて換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、燃料電池の発電に悪影響を及ぽさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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。
【０１０８】
なお、改質ガス温度測定用温度センサ６６を２個以上設置し、検出した温度の平均値を改質ガス温度としてもよい。
【０１０９】
また、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、各触媒充填層毎に改質ガス温度測定用温度センサ６６を設置することによって改質ガス温度を検出し、第８図に示した改質ガス温度と改質装置８のメタン転化率の関係を照合データとして照合することによって改質管毎のメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から各改質管毎の改質触媒の劣化状態の診断が可能であり、得られたメタン転化率あるいはメタン転化率から図１０に示した関係を用いて換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、改質管毎に燃料電池の発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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。
【０１１０】
図９は、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、改質ガス改質装置出口温度と改質装置８のメタン転化率の関係を示している。
【０１１１】
図９から、メタン転化率の低下とともに、改質ガス改質装置出口温度は上昇することが分かる。
【０１１２】
従って、改質ガス改質装置出口温度測定用温度センサ５１で改質ガス改質装置出口温度を検出し、図９に示した改質ガス改質装置出口温度と改質装置８のメタン転化率の関係を照合データとして照合することによって改質装置８のメタン転化率あるいは図１０を用いてメタン転化率から換算した改質触媒の劣化量を求めると、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置８の改質部４８の劣化状態の診断が可能であり、得られたメタン転化率あるいはメタン転化率から図１０に示した関係を用いて換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、燃料電池の発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限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。
【０１１３】
なお、改質ガス改質装置出口温度測定用温度センサ５１を２個以上設置し、検出した温度の平均値を改質ガス改質装置出口温度としてもよい。
【０１１４】
以上説明したように、本発明の燃料電池発電装置によれば、改質装置触媒充填層温度測定用温度センサ、改質装置改質管外壁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、改質装置バーナ燃焼排ガス改質装置出口温度測定用温度センサ、改質ガス温度測定用温度センサ、改質ガス改質装置出口温度測定用温度センサを１個以上設置するとともに、劣化診断手段、寿命診断手段、及ぴ照合データ選択手段を設置し、検出した改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口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手段に送信し、検出した温度を、照合データ選択手段で改質装置温度測定用温度センサで検出され信号に変換して送信された改質装置温度に対して選択され劣化診断手段に送信された予め決められた改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上と改質装置のメタン転化率の関係の照合データと劣化診断手段において照合することによって改質装置のメタン転化率あるいはメタン転化率から換算した改質触媒の劣化量を求め、メタン転化率の低下あるいは改質触媒の劣化量の増加から改質装置の劣化状態を診断するとともに、寿命診断手段において、改質装置触媒充填層温度測定用温度センサ、改質装置改質管外壁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、改質装置バーナ燃焼排ガス改質装置出口温度測定用温度センサ、改質ガス温度測定用温度センサ、改質ガス改質装置出口温度測定用温度センサのいずれか１個、あるいは１個以上で検出した改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上を、劣化診断手段で予め決められた検出温度（改質装置触媒充填層温度、改質装置改質管外壁温度、改質装置バーナ燃焼排ガス温度、改質装置バーナ燃焼排ガス改質装置出口温度、改質ガス温度、改質ガス改質装置出口温度のいずれか一つ、あるいは一つ以上）と改質装置のメタン転化率の関係と照合することによって求め送信されたメタン転化率あるはメタン転化率から換算した改質触媒の劣化量と発電時間の関係からメタン転化率の低下速度あるいは改質触媒の劣化速度を求め、発電に悪影響を及ぼさないメタン転化率の下限値に至るまでの期間、あるいは改質触媒の劣化量の上限値に至るまでの期間を計算することによって、
（１）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ガスの分析作業が不要となり、
（２）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となり、
（３）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。
【０１１５】
【発明の効果】
従って、以上説明したように、本発明によれば、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不可能であり、また、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となり、さらに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となり、あるいは、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劣化診断に時間がかかる等の従来の技術によるの燃料電池発電装置の問題点を解決し、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およびその改質装置の劣化診断方法を提供することができる。
【図面の簡単な説明】
【図１】図１は、本発明の一実施の形態による燃料電池発電装置の構成を示す接続図である。
【図２】図２は、従来の技術による燃料電池発電装置の構成を示す接続図である。
【図３】図３は、本発明による燃料電池発電装置の詳細を説明する改質装置の拡大図である。
【図４】図４は、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８の触媒充填層における各位置での改質装置触媒充填層温度と改質装置８のメタン転化率の関係を示す図である。
【図５】図５は、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８の触媒充填層における各位置での改質装置改質管外壁温度と改質装置のメタン転化率の関係を示す図である。
【図６】図６は、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８の触媒充填層における各位置での改質装置バーナ燃焼排ガス温度と改質装置８のメタン転化率の関係を示す図である。
【図７】図７は、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改質装置出口温度と改質装置８のメタン転化率の関係を示す図である。
【図８】図８は、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８の触媒充填層における各位置での改質ガス温度と改質装置８のメタン転化率の関係を示す図である。
【図９】図９は、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ガス改質装置出口温度と改質装置８のメタン転化率の関係を示す図である。
【図１０】図１０は、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８のメタン転化率と改質装置８の改質触媒の劣化量の関係を示す図である。
【図１１】図１１は、本実施の形態による燃料電池発電装置の作用を説明する劣化診断方法ならびにそれを実行するために記録媒体に記録されたプログラムに基づくフローチャートである。
【符号の説明】
１．原燃料ガス
２．改質ガス
３．遮断弁
４．都市ガス
５．劣化診断手段
６．改質装置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排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．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．改質装置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．改質装置温度測定用温度センサ
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改質装置出口温度測定用温度センサ
４８．改質部
４９．圧カセンサ
５０．燃料電池出力
５１．改質ガス改質装置出口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
６６．改質ガス温度測定用温度センサ
６７．照合データ選択手段
６８．寿命診断手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell power generator that generates hydrogen by reacting fuel and steam in a reformer to generate hydrogen, and reacts the hydrogen with oxygen in a cell stack, and a deterioration diagnosis of the reformer.To the lawA fuel cell capable of diagnosing the deterioration state of the reformer instantaneously and continuously on the spot without analyzing the reformed gas and determining the time for replacing the reforming catalyst. Deterioration diagnosis of power generator and its reformerTo the lawaboutYou.
[0002]
[Prior art]
FIG. 2 shows a configuration of a phosphoric acid type fuel cell power generation device using city gas as fuel as a conventional example of a fuel cell power generation device.
[0003]
That is, the main components of the fuel cell power generation device according to the prior art include a desulfurization device, an ejector, a reformer, a shift converter, a cell stack, a converter, a condenser, a pump, a steam separator, an air blower, and an evaporator. , Exhaust heat utilization systems, sensors, flow control valves, shut-off valves, and piping.
[0004]
In FIG. 2, 1 is a raw fuel gas, 2 is a reformed gas, 3 is a shutoff 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 air blower, 16 is power generation air, 17 is outside air, 18 is fuel electrode, 19 is electrolyte, 20 is oxidizer electrode, 21 is a cell stack, 22 is a voltage sensor, 23 is a current sensor, 24 is a converter, 25 is a load, 26 is battery cooling water, 27 is a steam separator, 28 is a steam separator heater, 29 is a catalyst packed bed. , 30 is a flow control valve, 31 is reforming steam, 33 is an evaporator, 34 is exhaust heat recovery steam, 35 is an exhaust heat utilization system, 36 is a refrigerant, 37 is an oxidant electrode exhaust gas, 38 is a condenser, 39 is exhaust gas, 40 is condensed water, 41 is for measuring reformer temperature Degree 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 a flow control valve. 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 starter burner, 60 is a shutoff valve, 61 is a reformer starter burner air, 62 is a shutoff valve, 63 is a cooler, 64 is a temperature sensor, and 65 is a shutoff valve.
[0005]
Hereinafter, the operation of this conventional fuel cell power generator will be described with reference to FIG.
[0006]
First, the shut-off valve 3 is opened, and the city gas 4 is supplied to a desulfurization unit 7 filled with a desulfurization catalyst (a cobalt-molybdenum-based catalyst and a zinc oxide adsorbent). Sulfur contained in the deodorant in the city gas 4 that causes deterioration of the catalyst of the fuel electrode 18 of the stack 21 is adsorbed and removed.
[0007]
The shut-off valve 57 is opened only when the fuel cell power generator is started, and the city gas 4 is supplied to the starter burner 59.
[0008]
The shut-off valve 60 is also opened only when the fuel cell power generator is started up, and the start-up burner air 61 is supplied to the start-up burner 59 by the air blower 15.
[0009]
In the start-up burner 59, when the fuel cell power generator is started, the city gas 4 burns, and the temperature of the reformer 8 is raised.
[0010]
Except during startup, the shutoff valves 57 and 60 are kept closed.
[0011]
The city gas supply amount is a fuel cell output 50 detected by the voltage sensor 22 and the current sensor 23 and a fuel cell output 50 preset from the reformer temperature detected by the reformer temperature measuring temperature sensor 41 and the reformer temperature. By adjusting the opening of the flow control valve 52 based on the relationship between the temperature and the degree of opening of the flow control valve 52 (ie, the amount of city gas supply), the city gas supply is reduced by the fuel cell output 50 and the reformer temperature. Set to a value appropriate for.
[0012]
The city gas 4 from which the sulfur content has been adsorbed and removed by the desulfurizer 7 is mixed with the reforming steam 31 supplied from the steam separator 27 by an ejector 53, and is filled with a reforming catalyst (usually a nickel-based catalyst). Is supplied to the reforming section 48 of the reforming apparatus 8.
[0013]
The supply amount of the reforming steam to the ejector 53 depends on the preset opening degree of the flow control valve 52 (that is, the supply amount of the city gas to the reformer 8) and the opening degree of the ejector 53 (that is, the reforming steam). By controlling the opening degree of the ejector 53 on the basis of the relationship (supply amount), control is performed so that a predetermined steam carbon ratio is set in advance.
[0014]
In the reformer 8, steam reforming of the city gas 4 as the fuel gas is performed, and the hydrogen-rich reformed gas 2 is produced.
[0015]
The steam reforming reaction of methane, which is the main component of city gas, is expressed by the following equation.
[0016]
(Steam reforming reaction of methane)
[0017]
(Equation 1)

[0018]
Since this hydrogen-rich reformed gas contains carbon monoxide which causes deterioration of the catalyst of the fuel electrode 18 of the cell stack 21, the reformed gas is filled with a shift catalyst (copper-zinc based catalyst). The carbon monoxide in the reformed gas is converted to carbon dioxide by a shift reaction represented by the following equation.
[0019]
(Shift reaction)
[0020]
(Equation 2)

[0021]
The shift converter 11 reduces the concentration of carbon monoxide in the reformed gas to 1% or less.
[0022]
The reformed gas exiting the shift converter 11 is supplied to the fuel electrode 18 of the cell stack 21 and used for power generation of the fuel cell.
[0023]
Further, a part of the outlet gas of the shift converter 11 is recycled to the desulfurization device 7, and hydrogen in the recycled gas is used for the desulfurization reaction.
[0024]
The supply amount of the recycle gas is determined by the relationship between the preset opening degree of the flow control valve 52 (that is, the supply amount of the city gas to the reformer 8) and the opening degree of the flow control valve 54 (that is, the supply amount of the recycle gas). By controlling the opening degree of the flow control valve 54 on the basis of the above, the supply amount is controlled to be a predetermined supply amount set in advance.
[0025]
On the other hand, to the oxidant electrode 20 of the cell stack 21, the open air 17 is taken in by using the air blower 15 by opening the shutoff valve 65 and supplied as power generation air 16.
[0026]
The supply amount of the power generation air 16 is determined based on the fuel cell output 50 detected by the voltage sensor 22 and the current sensor 23 and the preset fuel cell output 50 and the opening degree of the flow control valve 46 (that is, the power supply air supply amount). Based on the relationship, the opening degree of the flow control valve 46 is adjusted to a value that matches the fuel cell output 50.
[0027]
At the fuel electrode 18 of the cell stack 21, the hydrogen in the reformed gas is converted into hydrogen ions and electrons by the reaction shown in equation (3).
[0028]
(Fuel electrode reaction)
[0029]
(Equation 3)

[0030]
The hydrogen ions diffuse inside the electrolyte 19 and reach the oxidant electrode 20.
[0031]
On the other hand, electrons flow through an external circuit and are taken out as a fuel cell output 50.
[0032]
At the oxidant electrode, hydrogen ions diffused from the fuel electrode 18 through the electrolyte 19, electrons transferred from the fuel electrode 18 through an external circuit, and oxygen in the air at the three-phase interface by the reaction represented by the equation (4). And water is produced.
[0033]
(Oxidant electrode reaction)
[0034]
(Equation 4)

[0035]
Summarizing the equations (3) and (4), the whole battery reaction in the cell stack 21 can be expressed as a simple reaction in which water is produced from hydrogen and oxygen as shown in the equation (5).
[0036]
(Battery reaction)
[0037]
(Equation 5)

[0038]
The fuel cell output 50 obtained by the power generation is supplied to the load 25 after voltage conversion or DC-AC conversion is performed by the converter 24.
[0039]
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.
[0040]
About 20% of the remaining hydrogen remains in the anode exhaust gas as unreacted hydrogen.
[0041]
This is because, if all of the hydrogen in the reformed gas is consumed by the electrode reaction at the fuel electrode 18, the hydrogen locally runs short near the gas outlet, and the carbon of the fuel electrode substrate reacts instead of hydrogen to cause the cell stack 21 to react. Is deteriorated.
[0042]
The fuel electrode exhaust gas 13 containing unreacted hydrogen is supplied to the reformer burner 9 and used as a burner twist.
[0043]
Since the steam reforming reaction of methane shown in the equation (1) is an endothermic reaction, it is necessary to externally provide reaction heat to the reforming section 48 of the reformer 8.
[0044]
Therefore, 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, whereby the temperature of the reforming section 48 of the reformer 8 is increased. Is raised to about 700 ° C. at the maximum.
[0045]
The supply amount of the combustion air 12 is determined based on the reformer temperature preset from the reformer temperature detected by the reformer temperature measurement temperature sensor 41 and the opening degree of the flow control valve 45 (that is, the combustion air supply amount). The control is performed by adjusting the opening degree of the flow control valve 45 based on the relationship of (1).
[0046]
The reformer burner combustion exhaust gas 14 containing steam and unreacted steam generated by the combustion reaction of unreacted hydrogen in the fuel electrode exhaust gas 13 and the oxidizer electrode containing steam generated by the battery reaction shown in the equation (5) The exhaust gas 37 is sent to a condenser 38, where water vapor is removed as condensed water 40, and then released to the atmosphere as exhaust gas 39.
[0047]
The condensed water 40 is returned to the steam separator 27, and is used as the battery cooling water 26, the reforming steam 31, the exhaust heat recovery steam 34, and the like.
[0048]
Since the battery reaction shown in the equation (5) is an exothermic reaction, the temperature of the cell stack 21 increases as the power generation time elapses.
[0049]
When the temperature of the 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 easily occurs and the life is shortened.
[0050]
Then, the battery cooling water 26 is supplied from the steam separator 27 to the cooler 63 to cool the cell stack 21.
[0051]
The operating temperature of the cell stack 21 is generally set at around 190 ° C. in consideration of both the life and the performance.
[0052]
The supply amount of the battery cooling water 26 is controlled by adjusting the opening 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. .
[0053]
The battery cooling water 26 exiting the cell stack 21 is returned to the steam separator 27 in the form of a mixture of water and steam.
[0054]
At the start-up and when the pressure sensor 49 detects that the steam-water separator pressure has dropped below a predetermined pressure, a predetermined power is applied to the steam-water separator pressure by the pressure sensor 49 in advance. The water is supplied to the steam separator heater 28 until it detects that the pressure exceeds the set predetermined pressure, thereby generating steam.
[0055]
When the liquid level sensor 55 detects that the water level of the steam-water separator 27 has dropped below a predetermined water level, the liquid level sensor 55 sets the water level of the steam-water separator 27 in advance. The makeup water pump 43 is operated to supply makeup water 44 to the steam separator 27 until it is detected that the water level has reached the predetermined level.
[0056]
Of the steam supplied from the cell stack 21 to the steam separator 27 or the steam generated by the steam separator 27, steam other than the steam used for the reforming steam 31 is used as the steam 34 for exhaust heat recovery. 33, and is used for evaporating the refrigerant 35 of the exhaust heat utilization system 35.
[0057]
The condensed water 58 of the exhaust heat recovery steam 34 condensed in the evaporator 33 is returned to the steam separator 27.
[0058]
[Problems to be solved by the invention]
Next, problems of the above-described conventional fuel cell power generator will be described.
[0059]
That is, in the fuel cell power generator according to the conventional technology, an expensive gas analyzer such as a gas chromatograph is connected to the outlet of the reformer in order to diagnose the deterioration state of the reformer. Or by periodically sampling the reformed gas at the outlet of the reformer in a container and carrying out gas analysis to a certain place of the gas analyzer, thereby performing gas analysis. The methane conversion rate of the reformer 8 was determined from the methane amount (methane slip amount), and the deterioration state of the reformer 8 was diagnosed, and the time for replacing the reforming catalyst was determined.
[0060]
FIG. 10 shows, for reference, the methane conversion rate and the reforming unit of the reforming unit 8 when a 200 kW phosphoric acid-type fuel cell power generating unit is used to generate power at a rated output of 200 kW using city gas as fuel. 8 shows the relationship between the deterioration amounts of the reforming catalysts.
[0061]
The amount of methane in the reformed gas at the outlet of the reformer is detected, and the methane conversion of the reformer 8 is calculated to calculate the methane conversion or the amount of deterioration of the reforming catalyst converted from the methane conversion using FIG. Is obtained, it is possible to diagnose the deterioration state of the reforming unit 48 of the reformer 8 from the decrease in the methane conversion rate or the increase in the deterioration amount of the reforming catalyst, and to obtain the obtained methane conversion rate or deterioration of the reforming catalyst. The lowering rate of the methane conversion rate or the deterioration rate of the reforming catalyst is determined from the relationship between the amount and the power generation time, and the lower limit value of the methane conversion rate that does not adversely affect the power generation of the cell stack 21 or the deterioration catalyst of the reforming catalyst is determined. The replacement time of the reforming catalyst can be determined by calculating the period up to the upper limit of the amount.
[0062]
However, in these methods, it takes a long time for gas analysis, and it is impossible to diagnose the deterioration state of the reformer instantly on the spot. In addition, expensive gas analysis is required for the deterioration diagnosis of the reformer. In order to continuously diagnose the deterioration state of the reformer on the spot, a dedicated gas analyzer is required for the fuel cell power generator, or to the point where the gas analyzer is located. Since the sampling gas must be supplied, there is a problem that it takes a long time to perform the deterioration diagnosis.
[0063]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to take a long time to sample and analyze a reformed gas, and to perform a deterioration diagnosis of a reformer instantaneously. In addition, an expensive gas analyzer is required for the deterioration diagnosis of the reformer, and if the deterioration diagnosis of the reformer is to be continuously performed on the spot, a special gas is required for the fuel cell power generator. The problem of the fuel cell power generator according to the conventional technology, such as the need for an analyzer or the need to take the sampling gas to the point where the gas analyzer is located, which takes a long time for deterioration diagnosis, was solved. Fuel cell power generator capable of instantaneously and continuously performing deterioration diagnosis of a reformer and determining the timing of replacing a reforming catalyst, and a method of diagnosing deterioration of the reformerThe lawTo provide.
[0066]
[Means for Solving the Problems]
BookAccording to one embodiment of the present invention, as a means for solving the above problems,
A reforming apparatus having a reforming tube filled with a reforming catalyst for producing hydrogen by reacting fuel and steam;
It has a cell stack in which cells composed of a fuel electrode and an oxidizer electrode are sandwiched between electrolytes for generating electricity by reacting hydrogen produced by this reformer with oxygen.And
The temperature of the reforming section of the reformer is raised by burning the exhaust gas from the anode.Fuel cell power plant
Of the reformerBurner flue gas reformer outletReformer for measuring temperatureBurner flue gas reformer outletA temperature sensor for temperature measurement,
This reformerUpon receiving a temperature detection signal from a temperature sensor for measuring the temperature of the outlet of the burner flue gas reformer, the outlet of the reformer burner flue gas reformer is output.Reformer detected by temperature sensor for temperature measurementBurner flue gas reformer outlet temperature Predetermined reformer burner flue gas reformer outletDegradation diagnostic means for diagnosing the degradation state of the reformer by collating with temperature and collation data of the relationship between the methane conversion rates of the reformer;
The fuel cell power generation device characterized by having the following.
[0067]
According to another aspect of the present invention, as a means for solving the above problems,
A reforming apparatus having a reforming tube filled with a reforming catalyst for producing hydrogen by reacting fuel and steam;
It has a cell stack in which cells composed of a fuel electrode and an oxidizer electrode are sandwiched between electrolytes for generating electricity by reacting hydrogen produced by this reformer with oxygen.And
The temperature of the reforming section of the reformer is raised by burning the exhaust gas from the anode.Fuel cell power generation equipmentIn placeIn addition,
A temperature sensor for measuring the outlet temperature of the reformed gas reformer that measures the outlet temperature of the reformed gas reformer;
A temperature detection signal from the reformed gas reformer outlet temperature measuring temperature sensor is received, and the reformed gas reformer outlet temperature detected by the reformed gas reformer outlet temperature measuring temperature sensor is determined in advance. Deterioration diagnosis means for diagnosing the deterioration state of the reformer by comparing with the collation data of the relationship between the reformed gas reformer outlet temperature and the methane conversion rate of the reformer,
Fuel cell power generation device characterized by havingPlaceProvided.
[0068]
According to another aspect of the present invention, as a means for solving the above problems,
A reforming apparatus having a reforming tube filled with a reforming catalyst for producing hydrogen by reacting fuel and steam;
It has a cell stack in which cells composed of a fuel electrode and an oxidizer electrode are sandwiched between electrolytes for generating electricity by reacting hydrogen produced by this reformer with oxygen.And
The temperature of the reforming section of the reformer is raised by burning the exhaust gas from the anode.In a method for diagnosing deterioration of a reformer of a fuel cell power generator,
Of the reformerDetecting a burner flue gas reformer outlet temperature;
The detected reformer burner flue gas reformer outlet temperature is compared with predetermined collation data on the relationship between the reformer burner flue gas reformer outlet temperature and the methane conversion rate of the reformer to determine the reforming temperature. Diagnosing the degradation state of the quality device;
There is provided a method for diagnosing deterioration of a reformer of a fuel cell power generator, comprising:
[0069]
According to another aspect of the present invention, as a means for solving the above problems,
A reforming apparatus having a reforming tube filled with a reforming catalyst for producing hydrogen by reacting fuel and steam;
It has a cell stack in which cells composed of a fuel electrode and an oxidizer electrode are sandwiched between electrolytes for generating electricity by reacting hydrogen produced by this reformer with oxygen.And
The temperature of the reforming section of the reformer is raised by burning the exhaust gas from the anode.Diagnosis Method for Reforming Apparatus of Fuel Cell Power Generation ApparatusAt
Detecting a reformed gas reformer outlet temperature;
By comparing the detected reformed gas reformer outlet temperature with predetermined collation data of the relationship between the reformed gas reformer outlet temperature and the methane conversion rate of the reformer, the deterioration state of the reformer is determined. Diagnosing;
Fuel characterized by havingElectricDeterioration Diagnosis of Reformer of Pond Power PlantLawProvided.
[0070]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a fuel cell power generator according to the present invention will be described with reference to the drawings.
[0071]
FIG. 1 is a configuration diagram showing an embodiment of a fuel cell power generator according to the present invention.
[0072]
1, the same components as those in FIG. 2 described above are denoted by the same reference numerals, and description thereof will be omitted.
[0073]
FIG. 3 is an enlarged view of the reforming apparatus for explaining the details of the fuel cell power generator according to the present invention.
[0074]
An embodiment of the fuel cell power generator according to the present invention will be described with reference to FIGS.
[0075]
The fuel cell power generator according to the present embodiment differs from the conventional fuel cell power generator shown in FIG. 2 in that, as shown in FIGS. A temperature sensor 6 for measurement, a temperature sensor 32 for measuring the outer wall temperature of the reformer reformer tube, a temperature sensor 10 for measuring the temperature of the combustion exhaust gas of the reformer burner, a temperature sensor 47 for measuring the outlet temperature of the reformer burner combustion exhaust gas, The point that one or more reformed gas temperature measuring temperature sensor 66 and the reformed gas reforming device outlet temperature measuring temperature sensor 51 are newly provided, and the reforming device temperature detected by the reforming device temperature measuring temperature sensor 41 Is converted into a signal and transmitted. The relationship between the reformer catalyst packed bed temperature and the methane conversion rate of the reformer 8 corresponding to the reformer temperature, the reformer reformer tube outer wall temperature and the reformer Relation of methane conversion rate of unit 8, reforming The relationship between the temperature of the combustion exhaust gas and the methane conversion rate of the reformer 8, the relationship between the outlet temperature of the reformer burner flue gas reformer and the methane conversion rate of the reformer 8, the temperature of the reformed gas and the Collation data selection means 67 for selecting one or more of the relationship between the methane conversion rate, the relationship between the outlet temperature of the reformed gas reformer and the methane conversion rate of the reformer 8 as the collation data, 6, 32, 10, 47, 66, and 51, the reformer catalyst packed bed temperature, the reformer reformer tube outer wall temperature, the reformer burner combustion exhaust gas temperature, and the reformer burner combustion exhaust gas reformer outlet temperature. , The reforming gas temperature, the reforming gas reforming device outlet temperature, or one or more signals, and the verification data selecting means 67 selects and transmits the predetermined reforming device catalyst charge. Bed temperature and reformer 8 Verification data of the relationship between the methane conversion rate, verification data of the relation between the outer wall temperature of the reformer reforming pipe and the methane conversion rate of the reformer 8, and the relation between the combustion exhaust gas temperature of the reformer burner and the methane conversion rate of the reformer 8. Verification data, the verification data of the relationship between the reformer burner combustion exhaust gas reformer outlet temperature and the methane conversion rate of the reformer 8, the verification data of the relationship between the reformed gas temperature and the methane conversion rate of the reformer 8, The conversion from the methane conversion rate of the reformer 8 or the methane conversion rate by checking with one or more of the verification data of the relation between the outlet temperature of the reformer 8 and the methane conversion rate of the reformer 8 Deterioration diagnosis means 5 for diagnosing the deterioration state of the reforming unit 48 of the reformer 8 from the decrease in the methane conversion rate or the increase in the deterioration amount of the reforming catalyst, by determining the deterioration amount of the reformed catalyst, and detecting the temperature by each temperature sensor. Reformer catalyst charge Any one of packed bed temperature, reformer reformer tube outer wall temperature, reformer burner combustion exhaust gas temperature, reformer burner combustion exhaust gas reformer outlet temperature, reformed gas temperature, reformed gas reformer outlet temperature One or more of the predetermined detection temperatures (reformer catalyst packed bed temperature, reformer reformer outer tube temperature, reformer reformer outer tube temperature, reformer And / or more than one of reformer burner flue gas reformer outlet temperature, reformed gas temperature, reformed gas reformer outlet temperature) and methane conversion of reformer 8 The rate of decrease in the methane conversion rate or the conversion rate of the reforming catalyst is determined based on the relationship between the conversion rate of the methane converted or the methane conversion rate calculated from the conversion data and the amount of deterioration of the reforming catalyst converted from the methane conversion rate and the power generation time. deterioration The time to reach the lower limit of the methane conversion rate that does not adversely affect power generation or the period to the upper limit of the amount of deterioration of the reforming catalyst is calculated, The difference is that a life diagnosis means 68 for judging is newly provided.
[0076]
Here, the collation data selecting means 67 provides predetermined detection temperatures (reformer catalyst packed bed temperature, reformer reformer outer tube temperature, reformer burner combustion exhaust gas temperature, reformer burner combustion exhaust gas revision). Data of any one or more of the reformer outlet temperature, reformed gas temperature, and reformed gas reformer outlet temperature) and the methane conversion rate of the reformer 8 are shown in FIGS. It is assumed that it is created and stored in advance based on FIG. 9 and the like.
[0077]
Further, the reason that the life diagnosing means 68 can determine the replacement time of the reforming catalyst is that the deterioration amount of the reforming catalyst obtained in FIG. It is based on the fact that the replacement time of the reforming catalyst can be estimated from the time trend of the deterioration, and thus the function of plotting the deterioration amount of the reforming catalyst with time is provided to the life diagnosis means 68. It is assumed that
[0078]
The deterioration diagnosis means 5, the collation data selection means 67, and the life diagnosis means 68 are specifically executed by a personal computer (PC) or the like based on a deterioration diagnosis program recorded in a predetermined recording medium in advance. Shall be.
[0079]
Next, the operation of the fuel cell power generator according to the present embodiment will be described with reference to a flowchart based on the above-described deterioration diagnosis program shown in FIG.
[0080]
In the fuel cell power generator according to the present embodiment, first, at least one temperature sensor 6 for measuring the temperature of the catalyst packed bed of the reformer provided in the reforming section 48 of the reformer 8, the outer wall temperature of the reformer reforming pipe. Measurement temperature sensor 32, reformer burner combustion exhaust gas temperature measurement temperature sensor 10, reformer burner combustion exhaust gas reformer outlet temperature measurement temperature sensor 47, reformed gas temperature measurement temperature sensor 66, reformed gas reformer Temperature sensor 51 for measuring the outlet temperature of the reformer, the temperature of the packed bed of the reformer catalyst, the outer wall temperature of the reformer reforming tube, the temperature of the combustion exhaust gas of the reformer burner, the temperature of the outlet of the reformer burner combustion exhaust gas, the temperature of the reformer. One or more of the gas temperature and the outlet temperature of the reformed gas reformer are detected (step S1).
[0081]
Then, these temperature sensors transmit these temperature detection signals to the deterioration diagnosing means 5 (step S2).
[0082]
Next, the deterioration diagnosis unit 5 that receives these temperature detection signals converts the reformer temperature detected by the reformer temperature measuring temperature sensor 41 into a signal corresponding to the reformer temperature transmitted. The verification data of the relationship between the predetermined detected temperature selected and transmitted by the verification data selection means 67 and the methane conversion rate of the reformer 8, that is, the temperature of the reformer catalyst packed bed temperature and the methane conversion rate of the reformer 8 Verification data, the verification data of the relationship between the reformer reformer outer wall temperature and the methane conversion rate of the reformer 8, and the verification data of the relation between the reformer burner combustion exhaust gas temperature and the methane conversion rate of the reformer 8. Verification data of the relationship between the reformer burner combustion exhaust gas reformer outlet temperature and the methane conversion rate of the reformer 8, verification data of the relation between the reformed gas temperature and the methane conversion rate of the reformer 8, Reformer 8 and reformer outlet temperature One of matching data of the relationship between the methane conversion or matching the one or more (Step S3).
[0083]
In this way, the methane conversion rate of the reformer 8 or the deterioration amount of the reforming catalyst converted from the methane conversion rate is obtained, and based on the decrease in the methane conversion rate or the increase in the deterioration amount of the reforming catalyst, the reforming section of the reformer 8 is determined. The deterioration state of the forty-eight is diagnosed (step S4).
[0084]
That is, the life diagnosing means 68 detects the reformer catalyst packed bed temperature, the reformer reformer tube outer wall temperature, the reformer burner combustion exhaust gas temperature, and the reformer burner combustion exhaust gas reformer outlet temperature detected by each temperature sensor. , The reformed gas temperature, the reformed gas reformer outlet temperature, or one or more of the reformed gas reformer outlet temperatures is determined by the deterioration diagnostic means 5 by the collation data selecting means 67 and transmitted to the predetermined detection temperature (revision temperature). Temperature of reformer reformer tube, wall temperature of reformer burner flue gas, reformer burner flue gas reformer outlet temperature, reformer gas temperature, reformer gas reformer outlet temperature. One or more of them) and the methane conversion rate of the reformer 8 and the methane conversion rate obtained by collating with the collation data or the deterioration amount of the reforming catalyst converted from the methane conversion rate and the power generation. Time From the relationship, the rate of decrease in the methane conversion rate or the rate of deterioration of the reforming catalyst is determined, and the period until the lower limit of the methane conversion rate does not adversely affect the power generation, or the upper limit of the amount of deterioration of the reforming catalyst is reached. Is calculated (step S5).
[0085]
Then, the replacement time of the reforming catalyst is determined on the basis of the period up to the lower limit value of the methane conversion rate or the period up to the upper limit value of the deterioration amount of the reforming catalyst (step (1)). S6).
[0086]
In this way, the fuel cell power generation device according to the present embodiment differs from the fuel cell power generation device according to the prior art in determining the timing of replacing the reforming catalyst.
[0087]
FIG. 4 shows a catalyst packed bed (Ni-A1203 catalyst and RU-Al203) of the reformer 8 when a 200 kW phosphoric acid fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. The catalyst has a two-layer catalyst-packed bed, the same applies hereinafter), the raw fuel gas inlet, 20% of the total length of the catalyst-packed layer (converted from the raw fuel gas inlet, the same applies hereinafter), 40% of the total length of the catalyst-packed layer , The position of 60% of the total length of the catalyst packed bed, the position of 80% of the total length of the catalyst packed bed, and the reformer catalyst packed bed temperature and reformer 8 at the six positions of the reformed gas outlet of the catalyst packed bed. Shows the relationship between the methane conversion rates.
[0088]
From FIG. 4, it can be seen that the reformer catalyst packed bed temperature changes as the methane conversion decreases.
[0089]
Accordingly, the temperature of the reformer catalyst packed bed temperature is detected by the temperature sensor 6 for measuring the temperature of the reformer catalyst packed bed, and the relationship between the reformer catalyst packed bed temperature and the methane conversion rate of the reformer 8 shown in FIG. When the methane conversion rate of the reformer 8 or the amount of deterioration of the reforming catalyst converted from the methane conversion rate using FIG. 10 is obtained by collation as the collation data, the reduction of the methane conversion rate or the degradation amount of the reforming catalyst is obtained. It is possible to diagnose the deterioration state of the reforming section 48 of the reformer 8 from the increase, and to obtain the obtained methane conversion rate or the deterioration rate of the reforming catalyst converted from the methane conversion rate using the relationship shown in FIG. From the relationship between the amount and the power generation time, the rate of decrease in the methane conversion rate or the rate of deterioration of the reforming catalyst is calculated, and the period until the lower limit of the methane conversion rate does not adversely affect the power generation of the fuel cell, or the deterioration of the reforming catalyst Above quantity It can determine the replacement timing of the reforming catalyst by calculating the period up to the value.
[0090]
Alternatively, two or more temperature sensors 6 for measuring the temperature of the catalyst packed bed of the reforming apparatus may be provided, and the average value of the detected temperatures may be used as the temperature of the catalyst packed bed of the reforming apparatus.
[0091]
When two or more reforming tubes are installed in the reformer and there are two or more catalyst packed beds, a temperature sensor 6 for measuring the temperature of the catalyst packed bed of the reforming unit is installed for each catalyst packed bed. Thus, the temperature of the reformer catalyst packed bed is detected, and the relationship between the reformer catalyst packed bed temperature and the methane conversion rate of the reformer shown in FIG. When the amount of deterioration of the reforming catalyst converted from the methane conversion rate using FIG. 10 is obtained, the deterioration state of the reforming catalyst for each reforming pipe is determined from the decrease in the methane conversion rate or the increase in the deterioration amount of the reforming catalyst. It is possible to diagnose the rate of decrease in the methane conversion rate or the reforming rate from the relationship between the obtained methane conversion rate or the amount of deterioration of the reforming catalyst converted from the methane conversion rate using the relationship shown in FIG. 10 and the power generation time. Determine the catalyst degradation rate and use the reforming tube By calculating the period up to the lower limit of the methane conversion rate that does not adversely affect the power generation of the fuel cell, or the period up to the upper limit of the amount of deterioration of the reforming catalyst, the reform for each reforming pipe is calculated. The replacement time of the quality catalyst can be determined.
[0092]
Similarly, FIG. 5 shows a raw fuel gas inlet of the catalyst packed bed of the reformer 8 when a 200 kW phosphoric acid fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. 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, 60% of the total length of the catalyst packed bed, The relationship between the temperature of the outer wall of the reformer reforming pipe at the 80% position and the reforming gas outlet of the catalyst packed bed at six locations and the deterioration amount of the reforming catalyst of the reformer is shown.
[0093]
From FIG. 5, it can be seen that the temperature of the outer wall of the reformer reforming tube changes as the methane conversion rate decreases.
[0094]
Accordingly, the temperature of the reformer reforming tube outer wall temperature is detected by the temperature sensor 32 for measuring the reformer reforming tube outer wall temperature, and the reformer reforming tube outer wall temperature and the methane conversion rate of the reformer 8 shown in FIG. Is obtained as collation data to determine the methane conversion rate of the reformer 8 or the amount of deterioration of the reforming catalyst converted from the methane conversion rate using FIG. The deterioration state of the reforming section 48 of the reformer 8 can be diagnosed from the increase in the deterioration amount, and the obtained methane conversion rate or the conversion rate of the reforming catalyst converted from the methane conversion rate using the relationship shown in FIG. From the relationship between the amount of deterioration and the power generation time, the rate of decrease in the methane conversion rate or the rate of deterioration of the reforming catalyst is calculated, and the period until the lower limit of the methane conversion rate does not adversely affect the power generation of the fuel cell, or Deterioration limit It can determine the replacement timing of the reforming catalyst by calculating the period until the.
[0095]
Note that two or more temperature sensors 32 for measuring the temperature of the outer wall of the reformer reforming tube may be provided, and the average value of the detected temperatures may be used as the outer wall temperature of the reformer reforming tube.
[0096]
When two or more reforming tubes are installed in the reformer, the temperature sensor 32 for measuring the outer wall temperature of the reformer reforming tube is installed for each catalyst packed bed to improve the reformer. The outer wall temperature of the reforming tube is detected, and the relationship between the outer wall temperature of the reformer reforming tube and the methane conversion rate of the reformer 8 shown in FIG. When the deterioration amount of the reforming catalyst converted from the methane conversion rate is calculated using FIG. 10, the deterioration state of the reforming catalyst in each reforming pipe is diagnosed from the decrease in the methane conversion rate or the increase in the deterioration amount of the reforming catalyst. It is possible to determine the rate of decrease in the methane conversion rate or the conversion rate of the reforming catalyst from the relationship between the obtained methane conversion rate or the methane conversion rate and the amount of power generation time converted from the deterioration amount of the reforming catalyst using the relation shown in FIG. Deterioration rate is calculated and the fuel cell is started for each reforming tube. Replacement of the reforming catalyst for each reforming tube by calculating the period up to the lower limit of the methane conversion rate that does not adversely affect the reforming or the period up to the upper limit of the amount of deterioration of the reforming catalyst The timing can be determined.
[0097]
FIG. 6 shows a raw fuel gas inlet of the catalyst packed bed of the reformer 8 and a catalyst when a 200 kW phosphoric acid fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. 20% of the total length of the packed bed (converted from the raw fuel gas inlet, the same applies hereinafter), 40% of the total length of the packed bed, 60% of the total length of the packed bed, 80% of the total length of the packed bed 5 shows the relationship between the methane conversion rate of the reformer 8 and the methane conversion rate of the reformer burner exhaust gas at six positions at the reformed gas outlet of the catalyst packed bed and the reformed gas outlet of the catalyst packed bed.
[0098]
From FIG. 6, it can be seen that the reformer burner combustion exhaust gas temperature changes as the methane conversion rate decreases.
[0099]
Therefore, the temperature of the reformer burner flue gas is detected by the temperature sensor 10 for measuring the temperature of the reformer burner flue gas, and the relationship between the reformer burner flue gas temperature and the methane conversion rate of the reformer 8 shown in FIG. When the methane conversion rate of the reformer 8 or the amount of deterioration of the reforming catalyst converted from the methane conversion rate using FIG. 10 is obtained by collation as the collation data, the reduction of the methane conversion rate or the degradation amount of the reforming catalyst is obtained. From the increase, it is possible to diagnose the deterioration state of the reforming section 48 of the reformer 8, and the obtained methane conversion rate or the deterioration amount of the reforming catalyst converted from the methane conversion rate using the relationship shown in FIG. Determine the rate of decrease in methane conversion rate or the rate of deterioration of the reforming catalyst from the relationship between the power generation time and the period until the lower limit of the methane conversion rate that does not adversely affect the power generation of the fuel cell, or the reforming catalyst It can determine the replacement timing of the reforming catalyst by calculating the period up to the upper limit of the amount of degradation.
[0100]
Note that two or more temperature sensors 10 for measuring the temperature of the reformer burner flue gas may be provided, and the average value of the detected temperatures may be used as the reformer burner flue gas temperature.
[0101]
FIG. 7 further shows a reformer burner combustion exhaust gas reformer outlet temperature and a reformer when a 200 kW phosphoric acid fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. 8 shows the relationship between the methane conversion rates.
[0102]
FIG. 7 shows that the outlet temperature of the reformer burner flue gas reformer outlet increases as the methane conversion rate decreases.
[0103]
Therefore, by installing the temperature sensor 47 for measuring the outlet temperature of the reformer burner flue gas reformer, the outlet temperature of the reformer burner flue gas reformer is detected, and the reformer burner flue gas reformer shown in FIG. 7 is detected. By comparing the relationship between the reformer outlet temperature and the methane conversion rate of the reformer 8 as matching data, the methane conversion rate of the reformer 8 or the deterioration amount of the reforming catalyst converted from the methane conversion rate using FIG. If it is found, the deterioration state of the reforming section 48 of the reformer 8 can be diagnosed from the decrease in the methane conversion rate or the increase in the deterioration amount of the reforming catalyst, and the obtained methane conversion rate or methane conversion rate can be determined from FIG. The rate of decrease in methane conversion or the rate of deterioration of the reforming catalyst is determined from the relationship between the amount of deterioration of the reforming catalyst and the power generation time calculated using the relationship shown in the above, and has no adverse effect on the power generation of the fuel cell. It can determine the replacement timing of the reforming catalyst by calculating the period up to the upper limit value of the methane period up to the lower limit of the conversion or degradation of the reforming catalyst.
[0104]
Note that two or more temperature sensors 47 for measuring the outlet temperature of the reformer burner flue gas reformer outlet temperature may be provided, and the average value of the detected temperatures may be used as the reformer burner flue gas reformer outlet temperature.
[0105]
FIG. 8 shows a raw fuel gas inlet and a catalyst packed bed of the catalyst packed bed of the reformer 8 when a 200 kW phosphoric acid fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. 20% of the total length (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, 80% of the total length of the catalyst packed bed 6 shows the relationship between the position, the reformed gas temperature at six positions at the reformed gas outlet of the catalyst packed bed, and the methane conversion rate of the reformer 8.
[0106]
FIG. 8 shows that the reformed gas temperature changes as the methane conversion rate decreases.
[0107]
Accordingly, the reformed gas temperature is detected by the reformed gas temperature measuring temperature sensor 66, and the relationship between the reformed gas temperature and the methane conversion rate of the reformer 8 shown in FIG. When the amount of deterioration of the reforming catalyst converted from the methane conversion rate of the apparatus 8 or the methane conversion rate using FIG. 10 is determined, the reforming of the reforming apparatus 8 is performed based on a decrease in the methane conversion rate or an increase in the deterioration amount of the reforming catalyst. Diagnosis of the deterioration state of the part 48 is possible, and the methane conversion rate is obtained from the relationship between the obtained methane conversion rate or the conversion amount of the reforming catalyst converted from the methane conversion rate using the relationship shown in FIG. 10 and the power generation time. Obtain the rate of decrease or the rate of deterioration of the reforming catalyst, and determine the period until the lower limit of the methane conversion rate that does not adversely affect the power generation of the fuel cell, or the period until the upper limit of the amount of deterioration of the reforming catalyst is reached. To calculate What it is possible to determine the replacement time of the reforming catalyst.
[0108]
Note that two or more reformed gas temperature measuring temperature sensors 66 may be provided, and the average value of the detected temperatures may be used as the reformed gas temperature.
[0109]
When two or more reforming tubes are installed in the reformer and there are two or more catalyst packed beds, the reforming is performed by installing a temperature sensor 66 for measuring the temperature of the reformed gas for each catalyst packed bed. The temperature of the reformed gas is detected, and the relationship between the reformed gas temperature and the methane conversion rate of the reformer 8 shown in FIG. 8 is collated as collation data. When the deterioration amount of the reforming catalyst converted from the methane conversion rate is obtained, it is possible to diagnose the deterioration state of the reforming catalyst for each reforming pipe from the decrease in the methane conversion rate or the increase in the deterioration amount of the reforming catalyst, From the obtained methane conversion rate or the methane conversion rate, the rate of decrease in the methane conversion rate or the rate of deterioration of the reforming catalyst is determined from the relationship between the amount of deterioration of the reforming catalyst and the power generation time converted using the relationship shown in FIG. Poor influence on fuel cell power generation for each reforming tube By calculating the period up to the lower limit value of the methane conversion rate that does not affect the upper limit or the period up to the upper limit value of the deterioration amount of the reforming catalyst, the replacement time of the reforming catalyst for each reforming pipe can be calculated. Can be determined.
[0110]
FIG. 9 shows the temperature of the outlet of the reforming gas reformer and the temperature of the reforming device 8 when the 200 kW phosphoric acid type fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. It shows the relationship between methane conversion rates.
[0111]
From FIG. 9, it can be seen that the outlet temperature of the reformed gas reformer increases as the methane conversion rate decreases.
[0112]
Therefore, the outlet temperature of the reformed gas reformer is detected by the temperature sensor 51 for measuring the outlet temperature of the reformed gas reformer, and the outlet temperature of the reformed gas reformer and the methane conversion rate of the reformer 8 shown in FIG. Is obtained as collation data to determine the methane conversion rate of the reformer 8 or the amount of deterioration of the reforming catalyst converted from the methane conversion rate using FIG. The deterioration state of the reforming section 48 of the reformer 8 can be diagnosed from the increase in the deterioration amount, and the obtained methane conversion rate or the conversion rate of the reforming catalyst converted from the methane conversion rate using the relationship shown in FIG. From the relationship between the amount of deterioration and the power generation time, the rate of decrease in the methane conversion rate or the rate of deterioration of the reforming catalyst is calculated, and the period until the lower limit of the methane conversion rate does not adversely affect the power generation of the fuel cell, or Deterioration amount It can determine the replacement timing of the reforming catalyst by calculating the period up to the value.
[0113]
Note that two or more temperature sensors 51 for measuring the outlet temperature of the reformed gas reformer may be provided, and the average value of the detected temperatures may be used as the outlet temperature of the reformed gas reformer.
[0114]
As described above, according to the fuel cell power generator of the present invention, the temperature sensor for measuring the temperature of the catalyst packed bed of the reformer, the temperature sensor for measuring the outer wall temperature of the reformer reforming tube, and the temperature measurement of the combustion exhaust gas of the reformer burner And one or more temperature sensors for measuring the temperature at the outlet of the reformer burner flue gas reformer, the temperature sensor for measuring the temperature of the reformed gas, and the temperature sensor for measuring the temperature at the outlet of the reformed gas reformer Diagnosis means, life diagnosis means, and collation data selection means are installed and the detected reformer catalyst packed bed temperature, reformer reformer tube outer wall temperature, reformer burner combustion exhaust gas temperature, reformer burner combustion exhaust gas Converts any one or more of the reformer outlet temperature, reformed gas temperature, and reformed gas reformer outlet temperature to a signal, sends it to the deterioration diagnosis means, and selects the detected temperature as collation data. means A predetermined reformer catalyst packed bed temperature selected for the reformer temperature which is detected by the reformer temperature measuring temperature sensor and converted to a signal and transmitted to the deterioration diagnosis means, the reformer, One or more of reformer outer wall temperature, reformer burner combustion exhaust gas temperature, reformer burner combustion exhaust gas reformer outlet temperature, reformed gas temperature, reformed gas reformer outlet temperature The methane conversion rate of the reformer or the amount of deterioration of the reforming catalyst converted from the methane conversion rate is obtained by checking the collation data of the relationship of the methane conversion rate of the reformer with the deterioration diagnosis means, and the reduction of the methane conversion rate or The deterioration state of the reformer is diagnosed from the increase in the amount of deterioration of the reforming catalyst, and the life diagnosing means includes a temperature sensor for measuring the temperature of the packed bed of the reformer catalyst and a temperature for measuring the outer wall temperature of the reformer reforming tube. Temperature sensor for measuring the temperature of the combustion exhaust gas of the reformer burner, temperature sensor for measuring the temperature of the outlet of the reformer burner exhaust gas reformer, temperature sensor for measuring the temperature of the reformed gas, temperature for measuring the outlet temperature of the reformed gas reformer Reformer catalyst packed bed temperature detected by one or more of the sensors, reformer reformer tube outer wall temperature, reformer burner combustion exhaust gas temperature, reformer burner combustion exhaust gas reformer outlet temperature One or more of the reformed gas temperature and the outlet temperature of the reformed gas reformer, the detected temperature (reformer catalyst packed bed temperature, reformer reformer temperature, Pipe outer wall temperature, reformer burner flue gas temperature, reformer burner flue gas reformer outlet temperature, reformed gas temperature, reformed gas reformer outlet temperature, or more) Conversion of quality equipment The rate of decrease in methane conversion rate or the rate of degradation of the reforming catalyst is determined from the relationship between the conversion rate of the methane converted from the methane conversion rate or the methane conversion rate and the amount of power generation time. By calculating the period up to the lower limit of the methane conversion rate that does not adversely affect the power generation or the period up to the upper limit of the amount of deterioration of the reforming catalyst,
(1) Since the time for replacing the reforming catalyst is determined, it is not necessary to perform a time-consuming analysis operation of the reformed gas using an expensive gas analyzer such as a gas chromatograph for diagnosing the deterioration state of the reformer. Becomes
(2) It is possible to instantaneously and continuously diagnose the deterioration state of the reformer on the spot,
(3) Since the state of deterioration of the reforming catalyst can be constantly grasped and the time for replacing the reforming catalyst can be known in advance, the effect that the reforming catalyst can be replaced before the performance of the reforming device deteriorates can be obtained. There is.
[0115]
【The invention's effect】
Therefore, as described above, according to the present invention, it takes a long time to sample and analyze the reformed gas, and it is impossible to perform the deterioration diagnosis of the reformer instantaneously. An expensive gas analyzer is required for the deterioration diagnosis, and if the deterioration diagnosis of the reformer is to be continuously performed on the spot, a dedicated gas analyzer is required for the fuel cell power generator, or It solves the problems of the fuel cell power generator according to the conventional technology, such as taking a long time for deterioration diagnosis because the sampling gas must be taken to the place where the analyzer is located, and instantly and continuously reforming the reformer on the spot. Cell power generator capable of diagnosing deterioration of fuel and determining the timing of replacing the reforming catalyst, and a method of diagnosing deterioration of the reformerThe lawCan be provided.
[Brief description of the drawings]
FIG. 1 is a connection diagram showing a configuration of a fuel cell power generator according to one embodiment of the present invention.
FIG. 2 is a connection diagram showing a configuration of a conventional fuel cell power generator.
FIG. 3 is an enlarged view of a reformer illustrating details of a fuel cell power generator according to the present invention.
FIG. 4 is a diagram showing reforming at each position in a catalyst packed bed of a reformer 8 when power is generated at a rated output of 200 kW using city gas as fuel using a 200 kW phosphoric acid fuel cell power generator. FIG. 4 is a diagram showing a relationship between a temperature of a catalyst packed bed of a reformer 8 and a methane conversion rate of a reformer 8.
FIG. 5 is a diagram showing reforming at each position in a catalyst packed bed of a reformer 8 when power is generated at a rated output of 200 kW using city gas as fuel using a 200 kW phosphoric acid fuel cell power generator. FIG. 4 is a diagram showing a relationship between the outer wall temperature of the reformer and the methane conversion rate of the reformer.
FIG. 6 is a diagram showing reforming at each position in the catalyst packed bed of the reformer 8 when generating power at a rated output of 200 kW using city gas as fuel using a 200 kW phosphoric acid fuel cell power generator. FIG. 3 is a diagram showing a relationship between a combustion device combustion exhaust gas temperature and a methane conversion rate of a reformer 8.
FIG. 7 is a diagram showing a reformer burner combustion exhaust gas reformer outlet temperature and reforming when a 200 kW phosphoric acid fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. FIG. 4 is a diagram showing a relationship between methane conversion rates of a device 8;
FIG. 8 is a diagram showing reforming at each position in the catalyst packed bed of the reformer 8 in the case where a 200 kW phosphoric acid type fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. FIG. 3 is a diagram showing a relationship between a raw gas temperature and a methane conversion rate of a reformer 8.
FIG. 9 is a diagram showing the outlet temperature of the reformed gas reformer and the temperature of the reformer 8 when the 200 kW phosphoric acid fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. It is a figure which shows the relationship of a methane conversion.
FIG. 10 is a diagram showing the methane conversion rate of the reformer 8 and the power generation of the reformer 8 when the 200 kW phosphoric acid fuel cell power generator is used to generate power at a rated output of 200 kW using city gas as fuel. It is a figure which shows the relationship of the deterioration amount of a reforming catalyst.
FIG. 11 is a flowchart illustrating a deterioration diagnosis method for explaining the operation of the fuel cell power generator according to the present embodiment and a program recorded on a recording medium for executing the method.
[Explanation of symbols]
1. Raw fuel gas
2. Reformed gas
3. Shut-off valve
4. City Gas
5. Degradation diagnosis means
6. Temperature sensor for measuring the temperature of the catalyst packed bed in the reformer
7. Desulfurization equipment
8. Reformer
9. Reformer burner
10. Temperature sensor for measuring combustion exhaust gas temperature of reformer burner
11. Shift converter
12. Combustion air
13. Fuel electrode exhaust gas
14． Reformer burner flue gas
15. Air blower
16. Power generation air
17． Fresh air
18. Fuel electrode
19. Electrolytes
20. Oxidizer electrode
21. Cell stack
22. Voltage sensor
23. Current sensor
24. Conversion device
25. load
26. Battery cooling water
27. Steam separator
28. Steam separator heater
29. Catalyst packed bed
30. Flow control valve
31. Reforming steam
32. Temperature sensor for measuring the temperature of the outer wall of the reforming unit
33. Evaporator
34. Steam for waste heat recovery
35. Waste heat utilization system
36. Refrigerant
37. Oxidizer exhaust gas
38. Condenser
39. Exhaust gas
40. Condensed water
41. Temperature sensor for measuring reformer temperature
42. Reforming tube
43. Makeup water pump
44. Makeup water
45. Flow control valve
46. Flow control valve
47. Temperature sensor for measuring outlet temperature of reformer burner flue gas reformer
48. Reforming unit
49. Pressure sensor
50. Fuel cell output
51. Temperature sensor for measuring outlet temperature of reformed gas reformer
52. Flow control valve
53. Ejector
54. Flow control valve
55. Liquid level sensor
56. pump
57. Shut-off valve
58. Condensed water
59. Start-up burner
60. Shut-off valve
61. Burner air for starting reformer
62. Shut-off valve
63. Cooler
64. Temperature sensor
65. Shut-off valve
66. Temperature sensor for measuring reformed gas temperature
67. Verification data selection means
68. Lifetime diagnosis means

Claims (4)

A reforming apparatus having a reforming tube filled with a reforming catalyst for producing hydrogen by reacting fuel and steam;
The hydrogen made by reforming apparatus is reacted with oxygen electrolyte for performing power generation by chromatic and the cell stack formed by laminating a cell consisting of a sandwich fuel electrode and the oxidizer electrode,
In a fuel cell power generator that raises the temperature of a reforming section of the reformer by burning exhaust gas from the fuel electrode ,
A reformer burner combustion exhaust gas reformer outlet temperature measurement temperature sensor for measuring the reformer outlet temperature of the burner combustion exhaust gas of the reformer ,
Receiving the temperature detection signal from the reformer burner combustion exhaust gas reformer temperature sensor outlet temperature measurement, the reformer burner combustion exhaust gas reformer reformer burner combustion exhaust gas detected by the outlet temperature measuring temperature sensor diagnosing the deterioration state of the reformer by matching the collation data of methane conversion relation of a predetermined reformer burner combustion exhaust gas reformer outlet temperature and the reformer the reformer outlet temperature Degradation diagnosis means;
A fuel cell power generator comprising: A reforming apparatus having a reforming tube filled with a reforming catalyst for producing hydrogen by reacting fuel and steam;
It has a cell stack in which cells composed of a fuel electrode and an oxidizer electrode are sandwiched between electrolytes for generating electricity by reacting hydrogen produced by the reformer with oxygen,
Oite the fuel cell power generation equipment to increase the temperature of the reforming section of the reformer by burning the exhaust gas of the fuel electrode,
A temperature sensor for measuring the outlet temperature of the reformed gas reformer that measures the outlet temperature of the reformed gas reformer;
A temperature detection signal from the reformed gas reformer outlet temperature measuring temperature sensor is received, and the reformed gas reformer outlet temperature detected by the reformed gas reformer outlet temperature measuring temperature sensor is determined in advance. Deterioration diagnosis means for diagnosing the deterioration state of the reformer by comparing with the collation data of the relationship between the reformed gas reformer outlet temperature and the methane conversion rate of the reformer,
A fuel cell power generator comprising: A reforming apparatus having a reforming tube filled with a reforming catalyst for producing hydrogen by reacting fuel and steam;
The hydrogen made by reforming apparatus is reacted with oxygen electrolyte for performing power generation by chromatic and the cell stack formed by laminating a cell consisting of a sandwich fuel electrode and the oxidizer electrode,
In the method for diagnosing deterioration of a reformer of a fuel cell power generator, the temperature of a reformer of the reformer is raised by burning exhaust gas from the fuel electrode ,
Detecting a burner flue gas reformer outlet temperature of the reformer;
The detected reformer burner flue gas reformer outlet temperature is compared with predetermined collation data on the relationship between the reformer burner flue gas reformer outlet temperature and the methane conversion rate of the reformer to determine the reforming temperature. Diagnosing the degradation state of the quality device;
A method for diagnosing deterioration of a reformer of a fuel cell power generator , comprising: A reforming apparatus having a reforming tube filled with a reforming catalyst for producing hydrogen by reacting fuel and steam;
It has a cell stack in which cells composed of a fuel electrode and an oxidizer electrode are sandwiched between electrolytes for generating electricity by reacting hydrogen produced by the reformer with oxygen,
In the method for diagnosing deterioration of a reformer of a fuel cell power generator, the temperature of a reformer of the reformer is raised by burning the exhaust gas of the fuel electrode,
Detecting a reformed gas reformer outlet temperature;
By comparing the detected reformed gas reformer outlet temperature with predetermined collation data of the relationship between the reformed gas reformer outlet temperature and the methane conversion rate of the reformer, the deterioration state of the reformer is determined. Diagnosing;
A method for diagnosing deterioration of a reformer of a fuel cell power generator, comprising:

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