JP3975672B2

JP3975672B2 - Fuel cell power generator

Info

Publication number: JP3975672B2
Application number: JP2000350961A
Authority: JP
Inventors: 正高尾関; 彰成中村; 伸二宮内
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2000-11-17
Filing date: 2000-11-17
Publication date: 2007-09-12
Anticipated expiration: 2020-11-17
Also published as: JP2002158019A

Description

【０００１】
【発明の属する技術分野】
本発明は、燃料電池を用いて発電を行う燃料電池発電装置に関するものであり、特に水素を主体とする燃料を生成する燃料生成器の温度制御に関するものである。
【０００２】
【従来の技術】
図４は、従来の燃料電池発電装置の構成図である。燃料ガスと酸化剤とを用いて発電を行う燃料電池１と、都市ガス１３Ａなどの発電原料に水を添加して改質し水素に富んだ燃料ガスを生成する燃料生成器２と、燃料生成器２へ供給する発電原料および水の量を調節する発電原料調節器３と、都市ガス１３Ａなどの燃焼原料と燃料電池１より排出される残余燃料ガスとを燃焼する燃焼器４と、燃焼器４へ供給する燃焼原料の流量を調節して燃料生成器２の温度を発電原料から燃料を生成するのに必要な温度（Ｒu系触媒を用いた場合は約７００℃）に維持する燃焼原料調節器５と、燃焼器４にて完全燃焼が行われるように燃焼原料と残余燃料ガスとの量に応じて燃焼空気を燃焼器４へ供給する燃焼ファン６と、酸化剤としての空気を燃料電池１に供給するブロア８とを有している。
【０００３】
発電原料調節器３は、発電原料と水とを所定の割合、すなわち本燃料電池発電装置の構成で、発電原料に都市ガス１３Ａを用いた場合は、標準状態の都市ガス１３Ａ、１Ｌ／ｍｉｎ（＝1.67×10^-5ｍ³/sec）（以下、標準状態のガス量には「Ｎ」を付ける。すなわちここでは１ＮＬ／ｍｉｎとなる）に対して３ｇ／ｍｉｎ（＝5.0×10^-5ｋｇ/sec）程度の水を添加して、燃料電池１の発電に必要な量の燃料ガスを生成できるように、燃料生成器２に供給する発電原料（都市ガス１３Ａ）と水との量を調節する。
【０００４】
空気供給量調節器７内の残余水素推定器１０は、発電原料調節器３にて設定された発電原料である都市ガス１３Ａの流量から燃料生成器２が生成する水素量を演算すると共に、電流検知器９が検知する燃料電池１の発電電流から燃料電池１で消費される水素量を演算し、双方の演算結果より燃焼器４へ供給される残余燃料ガス中に含まれる水素量を演算する。
【０００５】
空燃比設定器１１は、残余水素推定器１０にて演算された量の残余燃料ガス中の水素と、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａとをちょうど燃焼させるだけの酸素を含む空気量を演算し、演算された空気量に対し所定の空燃比（例えば、空燃比１．５）の空気を燃焼器４へ供給するように燃焼ファン６の回転数を設定する。
【０００６】
上記従来例のような燃料電池発電装置において、通常の運転をしている場合は、燃料生成器２の温度を燃料を生成するのに必要な温度に維持するには残余燃料ガスを燃やしただけでは熱量が足らず、別途、燃焼原料を供給して燃料生成器２の温度を維持している。
【０００７】
そして、燃料生成器２の温度が、燃料を生成するのに必要な温度よりも高くなる場合、例えば発電電力が小さくなって残余燃料ガスの熱量が一時的に多くなると同時に燃料生成器２での燃料ガスの生成量が少なくなる場合や、環境温度が高く燃料生成器２の放熱量が少ない場合には、燃焼原料調整器５は、燃焼器４へ送る燃焼原料の量を減らしたり、供給停止することで燃焼器４の発熱量を調節し、燃料生成器２の温度を制御している。
【０００８】
しかしながら、本構成では燃料生成器２の温度を下げる手段は特に装備されていないので温度が下がるには時間がかかり、また、燃料生成器２の温度が燃料を生成するのに必要な温度よりも下がった場合でも、温度が上がり過ぎないように燃焼原料供給量を徐々に増やして温度を上げなくてはならず、燃料原料調節器５による燃焼原料供給量の制御だけでは燃料生成器２の温度安定性を確保することが難しいという問題点があった。
【０００９】
さらに、何らかの原因で燃料生成器２の温度が燃料を生成するのに必要な温度より上がり過ぎたような場合には、早急に燃料生成器２の温度を低下させないと、燃料生成器２が急速に性能劣化するとともに、最悪の場合、燃料生成器２が破損するが、それを防止する手段が装備されていないという問題点があった。
【００１０】
【発明が解決しようとする課題】
本発明は、上記従来技術が有する問題点を解決することを課題とする。
【００１１】
【課題を解決するための手段】
上記課題を解決するため、本発明は以下の燃料電池発電装置を構成したことを特徴とする。
【００１２】
第１の本発明の燃料電池発電装置は、燃料と酸化剤とで発電を行い水素を含む残余燃料ガスを排出する燃料電池本体と、発電原料と水とから前記燃料を生成する燃料生成器と、前記残余燃料ガスと燃焼原料とを燃やして前記燃料生成器を加熱する燃焼器と、前記燃焼器へ供給される前記燃焼原料の量を設定する燃焼原料調節器と、前記燃焼器へ空気を供給する空気供給器と、前記空気供給器から供給される空気の流量を調節する空気流量調節器とを備え、前記燃焼原料調節器により燃焼原料の供給量を調節し、前記燃料生成器の温度を制御する燃料電池発電装置であって、前記燃焼器へ供給される前記燃焼原料の量が、前記残余燃料ガス中の水素が余り始めていることを間接的に示すしきい値より小さい場合には、前記空気流量調節器は、前記燃焼器に通常より過剰の空気を供給するよう調節することを特徴とする。
【００１３】
第２の本発明の燃料電池発電装置は、燃料と酸化剤とで発電を行い水素を含む残余燃料ガスを排出する燃料電池本体と、発電原料と水とから前記燃料を生成する燃料生成器と、前記残余燃料ガスと燃焼原料とを燃やして前記燃料生成器を加熱する燃焼器と、前記燃焼器へ供給される前記燃焼原料の量を設定する燃焼原料調節器と、前記燃料生成器の温度を検出する温度検知器と、前記燃焼器へ空気を供給する空気供給器と、前記空気供給器から供給される空気の流量を調節する空気流量調節器とを備え、前記燃焼原料調節器により燃焼原料の供給量を調節し、前記燃料生成器の温度を制御する燃料電池発電装置であって、前記燃焼器へ供給される燃焼原料の量が、前記残余燃料ガス中の水素が余り始めていることを間接的に示すしきい値より小さい場合には、前記空気流量調節器は、前記温度検知器で検出される前記燃料生成器の温度を燃料を生成するのに必要な温度に保つように前記燃焼器に供給する空気の流量を調節することを特徴とする。
【００１４】
第３の本発明の燃料電池発電装置は、燃料と酸化剤とで発電を行い水素を含む残余燃料ガスを排出する燃料電池本体と、発電原料と水とから前記燃料を生成する燃料生成器と、前記残余燃料ガスと燃焼原料とを燃やして前記燃料生成器を加熱する燃焼器と、前記燃焼器へ供給される前記燃焼原料の量を設定する燃焼原料調節器と、前記燃料生成器の温度を検出する温度検知器と、前記水の流量を調節する水量調節器とを備え、前記燃焼原料調節器により燃焼原料の供給量を調節し、前記燃料生成器の温度を制御する燃料電池発電装置であって、前記燃焼器へ供給される燃焼原料の量が、前記残余燃料ガス中の水素が余り始めていることを間接的に示すしきい値より小さい場合には、前記水量調節器は、前記温度検知器で検出される前記燃料生成器の温度を燃料を生成するのに必要な温度に保つように前記燃料生成器に供給する水量を調節することを特徴とする。
【００１５】
【発明の実施の形態】
以下に、本発明の実施の形態を図面を参照して説明する。
【００１６】
（実施の形態１）
図１は、本発明の第１の実施の形態における燃料電池発電装置の構成図である。従来例と同じ構成要素には同じ番号を付与し、ここでの説明は省略する。
【００１７】
通常運転時には、燃料生成器２の温度を燃料を生成するのに必要な温度（Ｒu系触媒を用いた場合は７００℃）に維持するために、残余燃料ガスの他に別途、燃焼原料を供給している。しかしながら、電力需要が急に下がるなどで燃料電池１の発電量が急に少なくなると、残余燃料ガス中の水素が多くなる。これをこのまま燃焼器４で燃焼させると、水素を減らすために燃料生成器２の反応量を低下させる制御も同時に働くので燃料生成器２で消費する熱量は減少しており、結果として燃料生成器２の温度が燃料を生成するのに必要な温度よりも高くなる恐れがある。そこで以下のような制御を行うことで、別途燃料生成器２の冷却装置を設けることなしに、燃料生成器２の温度が燃料を生成するのに必要な温度よりも高くなることを防止する。
【００１８】
空気供給量調節器７内の残余水素推定器１０は、発電原料調節器３にて設定された発電原料である都市ガス１３Ａの流量から燃料生成器２が生成する水素量を演算すると共に、電流検知器９が検知する燃料電池１の発電電流から燃料電池１で消費される水素量を演算し、双方の演算結果より燃焼器４へ供給される残余燃料ガス中に含まれる水素量を演算する。第２空燃比設定器１２は、残余水素推定器１０にて演算された量の残余燃料ガス中の水素と、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａとをちょうど燃焼させるだけの酸素を含む空気量を演算する。そして、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａの供給量Ｇｏ［NＬ/min］に応じて（数１）によって演算される空燃比λを乗算した量の空気を燃焼器４へ供給するように燃焼ファン６の回転数を設定し、燃焼ファン６は空燃比λを乗算した量の空気を燃焼器４へ供給する。Ｇｏがしきい値ｘより大きい場合は通常モードの運転となるが、Ｇｏがしきい値ｘより小さい場合は冷却モードの運転となる。この時は、燃焼器４から燃料生成器２を通じて排出される排出ガスの量が増えるので、排出ガスに運ばれる熱量が増加し、その分燃料生成器２に伝達する熱量は減少する。よって、燃料生成器２の温度は空燃比λが一定の時（λ＝ａ）に比べて相対的に低下するようになり、燃料生成器２の温度の低下速度を速くすることができる。
【００１９】
【数１】

【００２０】
しきい値ｘは、残余燃料ガス中の水素が相対的に余り始める目安を間接的に示した値であり、このような時は燃料生成器２の反応量を下げる制御も働くので、何もしないと燃料生成器２の温度は異常上昇してしまうことがある。しきい値ｘを設けることで燃料生成器２の温度上昇を予測し、燃焼原料の供給量が０にならないうちから徐々に排出ガスに逃げる熱量を多くすることができるので、燃料生成器２の温度の低下速度を速くでき、燃料生成器２の温度の異常上昇を広い範囲で未然に防ぐことが可能となる。
【００２１】
以上のように、発電電力を小さくして残余燃料ガスが多くなった場合や、環境温度が高く燃料生成器２の放熱ロスが少ない場合、もしくは、なんらかの原因で燃料生成器２の温度が燃料を生成するのに必要な温度よりも高くなった場合でも、本実施の形態の構成によれば、燃料生成器２の温度をいち早く低下させることが可能となるので、燃料生成器２の温度安定性を確保することが容易になる。
【００２２】
また、燃料生成器２の温度が燃料を生成するのに必要な温度よりも下がりすぎた場合は、温度を確保するために燃焼原料調節器５の燃焼原料である都市ガス１３Ａの供給量を増やす制御が働くものであるが、本実施の形態の構成では、燃焼原料の供給量の増分を大きくして、温度の上昇速度を速くすることができる。オーバーシュートして温度が上がり過ぎた場合でも、まず、燃焼原料の供給量を下げる制御が働いた後、（数１）に従う制御を行うので、燃料生成器２の温度の低下速度は速く、燃料生成器２の温度が燃料を生成するのに必要な温度に容易に制御できるものであり、燃料生成器２の温度安定性を確保することが容易になる。
【００２３】
なお、しきい値ｘを大きくすると、空燃比が大きい運転状態に速く移行し、燃料生成器２に伝達する熱効率が下がる。逆に、しきい値ｘを小さくすると、空燃比が大きい運転状態に移行するのが遅れ、燃料生成器２の温度安定性を確保することが容易になるという本発明の効果が得られにくくなるので、発電装置の構成に鑑みてしきい値ｘは適切に設定すればよい。また、定常時の空燃比ａ、冷却モード時の空燃比ｂの値も発電装置の構成に鑑みて適切な値を選択すればよい。例えば発電原料と燃焼原料とに都市ガス１３Ａを用いた定格出力５ｋｗの燃料電池発電装置では、（数１）において、定常時の空燃比ａ＝1.5、冷却モード時の空燃比ｂ＝2.0、しきい値ｘをｘ＝1.0［NＬ/min］とした（数２）において、都市ガス１３Ａの供給量Ｇｏ［NＬ/min］の値により空燃比λを設定すると、燃料生成器の温度安定性を容易に確保できる燃料電池発電装置を構成できた。
【００２４】
【数２】

【００２５】
（実施の形態２）
図２は、本発明の第２の実施の形態における燃料電池発電装置の構成図である。従来例および第１の実施の形態と同じ構成要素は同じ番号を付与し、ここでの説明は省略する。
【００２６】
空気供給量調節器７内の残余水素推定器１０は、発電原料調節器３にて設定された発電原料である都市ガス１３Ａの流量から燃料生成器２が生成する水素量を演算するとともに、電流検知器９が検知する燃料電池１の発電電流から燃料電池１で消費される水素量を演算し、双方の演算結果より燃焼器４へ供給される残余燃料ガス中に含まれる水素量を演算する。
【００２７】
空気量演算器１３は、残余水素推定器１０にて演算された量の残余燃料ガス中の水素と、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａとをちょうど燃焼させるだけの酸素を含む空気量を演算する。そして、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａの供給量がしきい値以上の場合には、演算した空気量に対し、定常時の空燃比の空気を燃焼器４へ供給するように燃焼ファン６の回転数を設定する。
【００２８】
一方、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａの供給量がしきい値より小さい場合には、燃料生成器２の温度を検知する温度検知器１４に基づいて、燃料生成器２の温度を適正（燃料を生成するのに必要な温度）に保つように、燃焼ファン６の回転数を調節して空気量を制御する。空気量が多いと燃焼器４からの排出ガスに逃げる熱量が増え、結果として燃料生成器２の温度が下がり、空気量が少ないと燃焼器４からの排出ガスに逃げる熱量が減り、結果として燃料生成器２の温度が上がる。この時、空気量演算器１３は、残余水素推定器１０にて演算された量の残余燃料ガス中の水素と、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａとをちょうど燃焼させるだけの酸素を含む空気量を演算しており、空気量が少ない場合でも、空燃比は少なくとも１以上となるようになっている。燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａの供給量がしきい値より小さい場合は、残余水素が多くなっており、温度検知器１４で検知される温度は高くなることが想定される（排出ガスで燃料生成器２が昇温するまでには時間遅れがある）が、本実施の形態の構成によると、事前に燃焼原料である都市ガス１３Ａの供給量がしきい値より小さくなることを検知しているので、燃焼ファン６の回転数を通常より上げることで燃焼器４へ供給する空気量を多くし、排出ガスに逃げる熱量を増やして燃料生成器２の温度上昇を起こりづらくして、燃料生成器２の温度安定性を容易に確保できるようにしている。
【００２９】
また、何らかの原因で燃料生成器２の温度が燃料を生成するのに必要な温度より異常に上昇した場合は、燃焼原料調節器５が燃焼原料である都市ガス１３Ａの供給量を少なくして燃料生成器２の加熱量を小さくするものであり、そして、燃焼原料である都市ガス１３Ａの供給量がしきい値ｘより小さくなった段階で、燃料生成器２の温度が適正（燃料を生成するのに必要な温度）でない（高い）場合は、そのことを温度検知器１４で検知し、燃焼ファン６の回転数を通常より上げることで燃焼器４へ供給する空気量を多くし、排出ガスに逃げる熱量を増やして燃料生成器２の温度を急速に低下させ、異常昇温を防止し、燃料生成器２の温度が下がりすぎた場合は、そのことを温度検知器１４で検知し、燃焼ファン６の回転数を下げることで燃焼器４へ供給する空気量を少なくし、排出ガスに逃げる熱量を減らして燃料生成器２の温度を上昇させることで、燃料生成器２の温度を適正に保つものである。
【００３０】
以上のように、燃料電池発電装置において、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａの供給量がしきい値より小さい場合には、燃焼ファン６の回転数を調節して燃料生成器２の温度を適正温度に制御することにより、発電電力を小さくして残余燃料ガスが多くなった場合や、環境温度が高く燃料生成器２の放熱ロスが少ない場合、もしくは、なんらかの原因で燃料生成器２の温度が燃料を生成するのに必要な温度よりも高くなってしまった場合でも、燃料生成器２の温度をいち早く低下させることが可能となるので、燃料生成器２の温度安定性を確保することが容易になる。
【００３１】
（実施の形態３）
図３は、本発明の第３の実施の形態における燃料電池発電装置の構成図であり、従来例で示されるものと同じ構成要素については同じ番号を付与し、ここでの説明は省略する。
【００３２】
燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａの供給量がしきい値以上の場合には、第２発電原料調節器１５は、発電原料と水とを所定の割合（本燃料電池発電装置の構成では発電原料である都市ガス１３Ａの供給量１ＮＬ／ｍｉｎに対して水３ｇ／ｍｉｎ程度の割合）で燃料生成器２に供給する。
【００３３】
一方、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａの供給量がしきい値より小さい場合には、燃料生成器２の温度を検知する温度検知器１４の検出値に基づいて、燃料生成器２の温度が適正（燃料を生成するのに必要な温度）を保つよう、第２発電原料調節器１５は、燃料生成器２に供給する水の量を制御する。この時、供給される水の量の割合は、所定の割合、例えば発電原料である都市ガス１３Ａの供給量１ＮＬ／ｍｉｎに対して水３ｇ／ｍｉｎの割合を大幅に下回ることはない。
【００３４】
温度検知器１４の検出値が適正より高い場合は水が所定の割合より過剰に供給され、水が所定の割合より過剰に供給されると、過剰分に熱が奪われるので、燃料生成器２の温度は低下する。このような状態になるときは、燃焼器４へ供給される燃焼原料である都市ガス１３Ａの供給量がしきい値より小さい場合なので、燃料生成器２で発生している水素量は、燃料電池１で使われる水素量より過剰に生成されている状況にあり、燃料ガス中の水蒸気量が多少増えても燃料電池１での発電に与える影響は小さい。
【００３５】
また、温度検知器１４の検出値が適正より低い場合は水が所定の割合より少なく供給され、水が所定の割合より少なく供給されると、その分熱が余り、燃料生成器２の温度は上昇する。このような状態になるときは、燃焼器４へ供給される燃焼原料である都市ガス１３Ａの供給量がしきい値より小さい場合なので、燃料生成器２で発生している水素量は、燃料電池１で使われる水素量より過剰に生成されている状況にあり、燃料ガス中の水蒸気量が多少減っても燃料電池１での発電に与える影響は小さい。
【００３６】
このように、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａの供給量がしきい値より小さい場合には、温度検知器１４の検出値に基づいて、第２発電原料調節器１５が燃料生成器２に供給する水の量を制御することで、燃料生成器２の温度を適正に保つよう調節する。
【００３７】
また、何らかの原因で燃料生成器２の温度が燃料を生成するのに必要な温度より異常に上昇した場合は、燃焼原料調節器５が燃焼原料である都市ガス１３Ａの供給量を少なくして燃料生成器２の加熱量を小さくするものであり、そして、燃焼原料である都市ガス１３Ａの供給量がしきい値ｘより小さくなった段階で、燃料生成器２の温度が適正（燃料を生成するのに必要な温度）でない（高い）場合は、そのことを温度検知器１４で検知し、第２発電原料調節器１５が燃料生成器２に供給する水の量を多くし、燃料生成器２から水蒸気として運ばれる熱量を増加させることで燃料生成器２の温度を急速に低下させ異常昇温を防止し、燃料生成器２の温度が低下した場合は水の量を少なくし、燃料生成器２から水蒸気として運ばれる熱量を減少させることで燃料生成器２の温度を上昇させることで、燃料生成器２の温度を適正に保つものである。
【００３８】
以上のように、燃料電池発電装置において、燃焼原料調節器５にて設定された燃焼原料である都市ガス１３Ａの供給量がしきい値より小さい場合には、燃料生成器２に供給する水の量を増やして燃料生成器２の温度を適正温度に制御することにより、発電電力を小さくして残余燃料ガスが多くなった場合や、環境温度が高く燃料生成器２の放熱ロスが少ない場合、もしくは、なんらかの原因で燃料生成器２の温度が燃料を生成するのに必要な温度よりも高くなってしまった場合でも、燃料生成器２の温度をいち早く低下させることが可能となるので、燃料生成器２の温度安定性を確保することが容易になる。
【００３９】
なお、実施の形態１、実施の形態２において、燃焼器４に供給する空気量が多く、空燃比が極端に大きい場合や、燃焼器４中の気体の速度が極端に大きくなる場合は失火の可能性があるが、そのような状態は避けるように燃焼器４などを構成し、空燃比の上限を設けることは当然のことである。
【００４０】
また、実施の形態１と実施の形態３とを、あるいは実施の形態２と実施の形態３とを組み合わして構成しても、本発明の効果は何ら損なわれることはない。
【００４１】
さらに、実施の形態１〜実施の形態３において、しきい値は、残余燃料ガス中の水素が相対的に余る目安であり、このような時は通常の燃料電池発電装置では燃料生成器２の反応量を下げる制御も働くので、何もしないと燃料生成器２の温度は異常上昇してしまう。このしきい値は、燃焼原料調節器５で設定する燃焼原料の供給量で固定した値に設定しても良いし、燃焼器４に取り付けたフレームロッドなどの火炎検知器の検出結果に対応して変動する値に、しきい値を設定しても良い。
【００４２】
また、実施の形態１〜実施の形態３において、発電原料および燃焼原料は都市ガス１３Ａであるとして説明したが、これに限らず、燃料生成器に送って水素に富む燃料ガスを生成できる発電原料および燃焼原料、例えば他の、炭化水素を主体とする都市ガス種やＬＰガス、さらに液体燃料（灯油、ガソリン、メタノール、ジメチルエーテル等）でも良いし、発電原料と燃焼原料が異なっても良い。
【００４３】
そして、実施の形態１〜実施の形態３では、燃焼原料の供給量としきい値とを比較するように説明したが、燃焼原料調節器５の出力としきい値とを比較しても、燃焼器４へ供給される燃焼原料の量がしきい値より小さいと判断することが可能なので、同様の効果が得られることは明白である。
【００４４】
【発明の効果】
以上説明したところから明らかなように、本発明の構成によれば、燃料生成器の温度をすばやく下げることが可能となり、燃料生成器の温度を制御することが容易になるとともに、燃料生成器２の異常高温状態を、運転状態を持続しながら防ぐことができ、安定的かつ信頼性の高い燃料電池発電装置を提供することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態における燃料電池発電装置の構成図
【図２】本発明の第２の実施の形態における燃料電池発電装置の構成図
【図３】本発明の第３の実施の形態における燃料電池発電装置の構成図
【図４】従来の燃料電池発電装置の構成図
【符号の説明】
１燃料電池
２燃料生成器
３発電原料調節器
４燃焼器
５燃焼原料調節器
６燃焼ファン
７空気供給量調節器
８ブロワ
９電流検知器
１０残余水素推定器
１１空燃比設定器
１２第２空燃比設定器
１３空気量演算器
１４温度検知器
１５第２発電原料調節器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel cell power generator that generates power using a fuel cell, and more particularly to temperature control of a fuel generator that generates fuel mainly composed of hydrogen.
[0002]
[Prior art]
FIG. 4 is a configuration diagram of a conventional fuel cell power generator. A fuel cell 1 that generates power using fuel gas and an oxidant, a fuel generator 2 that generates water-rich fuel gas by adding water to a power generation material such as city gas 13A, and fuel generation A power generation raw material regulator 3 that adjusts the amount of power generation raw material and water supplied to the reactor 2, a combustor 4 that combusts combustion raw materials such as city gas 13 </ b> A and residual fuel gas discharged from the fuel cell 1, and a combustor Combustion raw material adjustment that maintains the temperature of the fuel generator 2 at the temperature required to generate fuel from the power generation raw material (about 700 ° C when using a Ru-based catalyst) by adjusting the flow rate of the combustion raw material supplied to 4 , A combustion fan 6 for supplying combustion air to the combustor 4 in accordance with the amount of the combustion raw material and the remaining fuel gas so that complete combustion is performed in the combustor 4, and air as an oxidant in the fuel cell 1 and a blower 8 for supplying to 1.
[0003]
The power generation raw material regulator 3 has a predetermined ratio of the power generation raw material and water, that is, when the city gas 13A is used as the power generation raw material in the configuration of the fuel cell power generation apparatus, the standard state city gas 13A, 1 L / min ( = 1.67 × 10 ⁻⁵ m ³ / sec) (hereinafter, “N” is added to the gas amount in the standard state. In other words, it is 1 NL / min here) 3 g / min (= 5.0 × 10 ⁻⁵ kg) / sec) of water is added to adjust the amount of power generation raw material (city gas 13A) and water supplied to the fuel generator 2 so that the amount of fuel gas required for power generation of the fuel cell 1 can be generated. To do.
[0004]
The residual hydrogen estimator 10 in the air supply amount regulator 7 calculates the amount of hydrogen produced by the fuel generator 2 from the flow rate of the city gas 13A, which is the power generation material set in the power generation material regulator 3, and the current. The amount of hydrogen consumed in the fuel cell 1 is calculated from the generated current of the fuel cell 1 detected by the detector 9, and the amount of hydrogen contained in the residual fuel gas supplied to the combustor 4 is calculated from the results of both calculations. .
[0005]
The air-fuel ratio setter 11 just burns the hydrogen in the residual fuel gas in the amount calculated by the residual hydrogen estimator 10 and the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5. Is calculated, and the rotational speed of the combustion fan 6 is set so that air having a predetermined air-fuel ratio (for example, air-fuel ratio 1.5) is supplied to the combustor 4 with respect to the calculated air amount. .
[0006]
In the fuel cell power generator as in the above-described conventional example, when the normal operation is performed, only the remaining fuel gas is burned in order to maintain the temperature of the fuel generator 2 at a temperature necessary for generating fuel. However, the amount of heat is insufficient, and the temperature of the fuel generator 2 is maintained by supplying combustion raw materials separately.
[0007]
When the temperature of the fuel generator 2 becomes higher than the temperature necessary for generating the fuel, for example, the generated power becomes small and the amount of heat of the remaining fuel gas temporarily increases. When the amount of generated fuel gas decreases, or when the environmental temperature is high and the amount of heat released from the fuel generator 2 is small, the combustion material regulator 5 reduces the amount of combustion material sent to the combustor 4 or stops the supply. Thus, the amount of heat generated by the combustor 4 is adjusted, and the temperature of the fuel generator 2 is controlled.
[0008]
However, in this configuration, there is no particular means for lowering the temperature of the fuel generator 2, so it takes time to lower the temperature, and the temperature of the fuel generator 2 is higher than the temperature necessary for generating fuel. Even if the temperature drops, the temperature of the fuel generator 2 must be increased by gradually increasing the amount of fuel supply so that the temperature does not rise too much. There was a problem that it was difficult to ensure stability.
[0009]
Furthermore, when the temperature of the fuel generator 2 is excessively higher than the temperature necessary for generating the fuel for some reason, the fuel generator 2 is rapidly turned on unless the temperature of the fuel generator 2 is decreased immediately. However, in the worst case, the fuel generator 2 is damaged, but there is a problem that no means for preventing it is provided.
[0010]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-described problems of the prior art.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is characterized in that the following fuel cell power generator is configured.
[0012]
A fuel cell power generator according to a first aspect of the present invention includes a fuel cell main body that generates power with fuel and an oxidant and discharges residual fuel gas containing hydrogen, a fuel generator that generates the fuel from a power generation raw material and water, A combustor that burns the residual fuel gas and combustion raw material to heat the fuel generator; a combustion raw material regulator that sets an amount of the combustion raw material supplied to the combustor; and air to the combustor. An air supply device to be supplied; and an air flow rate adjuster for adjusting a flow rate of air supplied from the air supply device, wherein a supply amount of the combustion raw material is adjusted by the combustion raw material regulator, and a temperature of the fuel generator When the amount of the combustion raw material supplied to the combustor is smaller than a threshold value indirectly indicating that the hydrogen in the residual fuel gas starts to be surplus The air flow regulator is And adjusting to supply excess air than normal to the combustor.
[0013]
A fuel cell power generator according to a second aspect of the present invention includes a fuel cell main body that generates power with fuel and an oxidant and discharges residual fuel gas containing hydrogen, a fuel generator that generates the fuel from a power generation raw material and water, A combustor for burning the residual fuel gas and a combustion raw material to heat the fuel generator; a combustion raw material regulator for setting an amount of the combustion raw material supplied to the combustor; and a temperature of the fuel generator A temperature detector that detects air, an air supplier that supplies air to the combustor, and an air flow controller that adjusts a flow rate of air supplied from the air supplier, and is burned by the combustion material regulator A fuel cell power generator for controlling the temperature of the fuel generator by adjusting the supply amount of the raw material, wherein the amount of the combustion raw material supplied to the combustor is such that the hydrogen in the residual fuel gas starts to be excessive than indirectly indicates thresholds In this case, the air flow controller adjusts the flow rate of air supplied to the combustor so as to keep the temperature of the fuel generator detected by the temperature detector at a temperature necessary for generating fuel. It is characterized by adjusting.
[0014]
A fuel cell power generator according to a third aspect of the present invention includes a fuel cell main body that generates power with fuel and an oxidant and discharges residual fuel gas containing hydrogen, a fuel generator that generates the fuel from a power generation raw material and water, A combustor for burning the residual fuel gas and a combustion raw material to heat the fuel generator; a combustion raw material regulator for setting an amount of the combustion raw material supplied to the combustor; and a temperature of the fuel generator A fuel cell power generator comprising: a temperature detector that detects the amount of water; and a water amount adjuster that adjusts the flow rate of the water, wherein the combustion raw material adjuster adjusts the supply amount of the combustion raw material and controls the temperature of the fuel generator When the amount of the combustion raw material supplied to the combustor is smaller than a threshold value indirectly indicating that the hydrogen in the residual fuel gas starts to be excessive, the water amount regulator The fuel production detected by the temperature detector The temperature of the vessel and adjusting the amount of water supplied to the fuel generator so as to keep the temperature required to produce the fuel.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0016]
(Embodiment 1)
FIG. 1 is a configuration diagram of a fuel cell power generator according to a first embodiment of the present invention. The same components as those in the conventional example are given the same numbers, and the description thereof is omitted here.
[0017]
During normal operation, in order to maintain the temperature of the fuel generator 2 at the temperature required for generating fuel (700 ° C when using a Ru-based catalyst), in addition to the remaining fuel gas, a separate combustion raw material is supplied. is doing. However, if the amount of power generated by the fuel cell 1 suddenly decreases due to a sudden decrease in power demand or the like, the amount of hydrogen in the remaining fuel gas increases. When this is burned in the combustor 4 as it is, the control for lowering the reaction amount of the fuel generator 2 is also performed simultaneously to reduce hydrogen, so the amount of heat consumed in the fuel generator 2 is reduced, and as a result, the fuel generator 2 The temperature of 2 may be higher than that required to produce fuel. Therefore, by performing the following control, it is possible to prevent the temperature of the fuel generator 2 from becoming higher than the temperature necessary for generating fuel without providing a separate cooling device for the fuel generator 2.
[0018]
The residual hydrogen estimator 10 in the air supply amount regulator 7 calculates the amount of hydrogen produced by the fuel generator 2 from the flow rate of the city gas 13A, which is the power generation material set in the power generation material regulator 3, and the current. The amount of hydrogen consumed in the fuel cell 1 is calculated from the generated current of the fuel cell 1 detected by the detector 9, and the amount of hydrogen contained in the residual fuel gas supplied to the combustor 4 is calculated from the results of both calculations. . The second air-fuel ratio setting unit 12 just burns the hydrogen in the residual fuel gas in the amount calculated by the residual hydrogen estimator 10 and the city gas 13A which is the combustion raw material set by the combustion raw material regulator 5. Calculate the amount of air that contains enough oxygen. Then, according to the supply amount Go [NL / min] of the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5, the amount of air multiplied by the air-fuel ratio λ calculated by (Equation 1) is combusted. The rotational speed of the combustion fan 6 is set so as to be supplied to the combustor 4, and the combustion fan 6 supplies the combustor 4 with an amount of air multiplied by the air-fuel ratio λ. When Go is larger than the threshold value x, the operation is performed in the normal mode, but when Go is smaller than the threshold value x, the operation is performed in the cooling mode. At this time, since the amount of exhaust gas discharged from the combustor 4 through the fuel generator 2 increases, the amount of heat carried to the exhaust gas increases, and the amount of heat transferred to the fuel generator 2 decreases accordingly. Therefore, the temperature of the fuel generator 2 is relatively decreased as compared with the case where the air-fuel ratio λ is constant (λ = a), and the temperature decrease rate of the fuel generator 2 can be increased.
[0019]
[Expression 1]

[0020]
The threshold value x is a value that indirectly indicates an indication that the hydrogen in the residual fuel gas starts to relatively remain. In such a case, the control for lowering the reaction amount of the fuel generator 2 also works. Otherwise, the temperature of the fuel generator 2 may rise abnormally. By providing the threshold value x, the temperature rise of the fuel generator 2 can be predicted, and the amount of heat that gradually escapes to the exhaust gas from when the supply amount of the combustion raw material does not become zero can be increased. The rate of temperature decrease can be increased, and an abnormal increase in the temperature of the fuel generator 2 can be prevented in a wide range.
[0021]
As described above, when the generated power is reduced and the residual fuel gas is increased, when the environmental temperature is high and the heat dissipation loss of the fuel generator 2 is small, or for some reason, the temperature of the fuel generator 2 reduces the fuel. Even when the temperature is higher than the temperature required for generation, according to the configuration of the present embodiment, the temperature of the fuel generator 2 can be quickly reduced, so that the temperature stability of the fuel generator 2 can be reduced. It becomes easy to ensure.
[0022]
In addition, when the temperature of the fuel generator 2 is too lower than the temperature necessary for generating the fuel, the supply amount of the city gas 13A that is the combustion raw material of the combustion raw material regulator 5 is increased in order to secure the temperature. Although the control works, in the configuration of the present embodiment, the increment of the supply amount of the combustion raw material can be increased to increase the temperature increase rate. Even if the temperature rises excessively due to overshoot, first, the control to lower the supply amount of the combustion raw material is performed, and then the control according to (Equation 1) is performed, so the rate of temperature decrease of the fuel generator 2 is fast, and the fuel The temperature of the generator 2 can be easily controlled to a temperature necessary to generate the fuel, and it becomes easy to ensure the temperature stability of the fuel generator 2.
[0023]
When the threshold value x is increased, the operating state with a large air-fuel ratio is quickly shifted to reduce the thermal efficiency transmitted to the fuel generator 2. On the other hand, if the threshold value x is decreased, it is difficult to obtain the effect of the present invention that it is easy to ensure the temperature stability of the fuel generator 2 because the transition to an operating state with a large air-fuel ratio is delayed. Therefore, the threshold value x may be set appropriately in view of the configuration of the power generation device. In addition, the values of the air-fuel ratio a in the steady state and the air-fuel ratio b in the cooling mode may be selected appropriately in view of the configuration of the power generator. For example, in a fuel cell power generator with a rated output of 5 kw using city gas 13A as a power generation raw material and a combustion raw material, in (Equation 1), the air-fuel ratio a in steady state is 1.5 and the air-fuel ratio b in cooling mode is 2.0. When the threshold value x is set to x = 1.0 [NL / min] (Expression 2) and the air-fuel ratio λ is set by the value of the city gas 13A supply amount Go [NL / min], the temperature stability of the fuel generator is increased. A fuel cell power generator that can be easily secured was constructed.
[0024]
[Expression 2]

[0025]
(Embodiment 2)
FIG. 2 is a configuration diagram of the fuel cell power generation device according to the second embodiment of the present invention. The same components as those of the conventional example and the first embodiment are given the same numbers, and the description thereof is omitted here.
[0026]
The residual hydrogen estimator 10 in the air supply amount regulator 7 calculates the amount of hydrogen produced by the fuel generator 2 from the flow rate of the city gas 13A, which is the power generation material set in the power generation material regulator 3, and the current. The amount of hydrogen consumed in the fuel cell 1 is calculated from the generated current of the fuel cell 1 detected by the detector 9, and the amount of hydrogen contained in the residual fuel gas supplied to the combustor 4 is calculated from the results of both calculations. .
[0027]
The air amount calculator 13 just burns the hydrogen in the residual fuel gas in the amount calculated by the residual hydrogen estimator 10 and the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5. The amount of air containing oxygen is calculated. When the supply amount of the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5 is equal to or greater than the threshold value, the air of the air-fuel ratio at the steady state is changed to the combustor 4 with respect to the calculated air amount. The rotational speed of the combustion fan 6 is set so as to be supplied to the engine.
[0028]
On the other hand, when the supply amount of the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5 is smaller than the threshold value, the fuel is detected based on the temperature detector 14 that detects the temperature of the fuel generator 2. The amount of air is controlled by adjusting the number of revolutions of the combustion fan 6 so that the temperature of the generator 2 is kept appropriate (temperature necessary for generating fuel). When the amount of air is large, the amount of heat that escapes to the exhaust gas from the combustor 4 increases, and as a result, the temperature of the fuel generator 2 decreases, and when the amount of air is small, the amount of heat that escapes to the exhaust gas from the combustor 4 decreases. The temperature of the generator 2 increases. At this time, the air amount calculator 13 just calculates the amount of hydrogen in the residual fuel gas calculated by the residual hydrogen estimator 10 and the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5. The amount of air containing oxygen that can be burned is calculated, and even when the amount of air is small, the air-fuel ratio is at least 1 or more. When the supply amount of the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5 is smaller than the threshold value, the residual hydrogen is increased, and the temperature detected by the temperature detector 14 is increased. (There is a time delay until the temperature of the fuel generator 2 rises with exhaust gas), but according to the configuration of the present embodiment, the supply amount of the city gas 13A as the combustion raw material is the threshold in advance. Since it is detected that the value is smaller than the value, the amount of air supplied to the combustor 4 is increased by increasing the rotational speed of the combustion fan 6 to increase the amount of heat escaping to the exhaust gas, thereby increasing the temperature of the fuel generator 2. It is difficult for the temperature to rise, and the temperature stability of the fuel generator 2 can be easily secured.
[0029]
Also, if for some reason the temperature of the fuel generator 2 rises abnormally above the temperature necessary to generate the fuel, the combustion raw material regulator 5 reduces the supply amount of the city gas 13A as the combustion raw material, and the fuel The heating amount of the generator 2 is reduced, and when the supply amount of the city gas 13A as the combustion raw material becomes smaller than the threshold value x, the temperature of the fuel generator 2 is appropriate (generates fuel). If the temperature is not (high), the temperature is detected by the temperature detector 14, and the amount of air supplied to the combustor 4 is increased by increasing the rotational speed of the combustion fan 6. The temperature of the fuel generator 2 is rapidly decreased by increasing the amount of heat that escapes to prevent abnormal temperature rise, and if the temperature of the fuel generator 2 is too low, this is detected by the temperature detector 14 and burned. Burning by reducing the rotation speed of fan 6 To reduce the amount of air supplied to the vessel 4, by reducing the amount of heat escaping to the exhaust gas increases the temperature of the fuel generator 2, it is intended to keep the temperature of the fuel generator 2 properly.
[0030]
As described above, in the fuel cell power generator, when the supply amount of the city gas 13A as the combustion raw material set by the combustion raw material regulator 5 is smaller than the threshold value, the rotational speed of the combustion fan 6 is adjusted. By controlling the temperature of the fuel generator 2 to an appropriate temperature, the generated power is reduced to increase the amount of residual fuel gas, the environment temperature is high, and the heat loss of the fuel generator 2 is small, or Even if the temperature of the fuel generator 2 becomes higher than the temperature necessary for generating the fuel due to the cause, the temperature of the fuel generator 2 can be quickly reduced. It becomes easy to ensure temperature stability.
[0031]
(Embodiment 3)
FIG. 3 is a configuration diagram of the fuel cell power generation device according to the third embodiment of the present invention. The same reference numerals are given to the same components as those shown in the conventional example, and the description thereof is omitted here.
[0032]
When the supply amount of the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5 is equal to or greater than the threshold value, the second power generation raw material regulator 15 sets the power generation raw material and water to a predetermined ratio (main In the configuration of the fuel cell power generator, water is supplied to the fuel generator 2 at a rate of about 3 g / min of water with respect to the supply amount of 1 NL / min of the city gas 13A as the power generation raw material.
[0033]
On the other hand, when the supply amount of the city gas 13A that is the combustion material set by the combustion material regulator 5 is smaller than the threshold value, it is based on the detection value of the temperature detector 14 that detects the temperature of the fuel generator 2. Thus, the second power generation raw material regulator 15 controls the amount of water supplied to the fuel generator 2 so that the temperature of the fuel generator 2 is maintained at an appropriate temperature (temperature necessary for generating fuel). At this time, the ratio of the amount of supplied water is not significantly lower than a predetermined ratio, for example, a ratio of 3 g / min of water with respect to a supply amount of 1 NL / min of city gas 13A as a power generation raw material.
[0034]
When the detection value of the temperature detector 14 is higher than appropriate, water is supplied in excess of a predetermined ratio, and when water is supplied in excess of the predetermined ratio, heat is taken away excessively, so the fuel generator 2 The temperature drops. In such a state, since the supply amount of the city gas 13A as the combustion raw material supplied to the combustor 4 is smaller than the threshold value, the amount of hydrogen generated in the fuel generator 2 is the fuel cell. 1 is generated in excess of the amount of hydrogen used in 1, and even if the amount of water vapor in the fuel gas slightly increases, the effect on power generation in the fuel cell 1 is small.
[0035]
In addition, when the detection value of the temperature detector 14 is lower than appropriate, water is supplied in less than a predetermined ratio, and when water is supplied in less than a predetermined ratio, the heat is increased and the temperature of the fuel generator 2 is To rise. In such a state, since the supply amount of the city gas 13A as the combustion raw material supplied to the combustor 4 is smaller than the threshold value, the amount of hydrogen generated in the fuel generator 2 is the fuel cell. 1 is generated in excess of the amount of hydrogen used in 1, and even if the amount of water vapor in the fuel gas is somewhat reduced, the effect on power generation in the fuel cell 1 is small.
[0036]
As described above, when the supply amount of the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5 is smaller than the threshold value, the second power generation raw material regulation is performed based on the detection value of the temperature detector 14. By controlling the amount of water supplied to the fuel generator 2 by the generator 15, the temperature of the fuel generator 2 is adjusted to be maintained appropriately.
[0037]
Also, if for some reason the temperature of the fuel generator 2 rises abnormally above the temperature necessary to generate the fuel, the combustion raw material regulator 5 reduces the supply amount of the city gas 13A as the combustion raw material, and the fuel The heating amount of the generator 2 is reduced, and when the supply amount of the city gas 13A as the combustion raw material becomes smaller than the threshold value x, the temperature of the fuel generator 2 is appropriate (generates fuel). If the temperature is not (high), the temperature detector 14 detects this, and the amount of water supplied to the fuel generator 2 by the second power generation material regulator 15 is increased. The temperature of the fuel generator 2 is rapidly reduced by increasing the amount of heat carried as steam from the fuel to prevent abnormal temperature rise, and when the temperature of the fuel generator 2 decreases, the amount of water is reduced, and the fuel generator 2 2 Reduces the amount of heat carried as water vapor Thereby increasing the temperature of the fuel generator 2 is by, but to keep the temperature of the fuel generator 2 properly.
[0038]
As described above, in the fuel cell power generation device, when the supply amount of the city gas 13A that is the combustion raw material set by the combustion raw material regulator 5 is smaller than the threshold value, the water supplied to the fuel generator 2 By increasing the amount and controlling the temperature of the fuel generator 2 to an appropriate temperature, if the generated power is reduced and the residual fuel gas increases, or if the ambient temperature is high and the heat loss of the fuel generator 2 is small, Alternatively, even if the temperature of the fuel generator 2 becomes higher than the temperature necessary for generating the fuel for some reason, the temperature of the fuel generator 2 can be quickly reduced. It becomes easy to ensure the temperature stability of the vessel 2.
[0039]
In the first and second embodiments, when the amount of air supplied to the combustor 4 is large and the air-fuel ratio is extremely large, or when the gas velocity in the combustor 4 is extremely large, misfires may occur. Although there is a possibility, it is natural that the combustor 4 is configured so as to avoid such a state and an upper limit of the air-fuel ratio is provided.
[0040]
Even if the first embodiment and the third embodiment are combined or the second embodiment and the third embodiment are combined, the effect of the present invention is not impaired at all.
[0041]
Further, in the first to third embodiments, the threshold value is a measure for relatively remaining hydrogen in the remaining fuel gas. In such a case, the fuel generator 2 of the normal fuel cell power generator is used in such a case. Since the control for reducing the reaction amount also works, if nothing is done, the temperature of the fuel generator 2 will rise abnormally. This threshold value may be set to a value fixed by the supply amount of the combustion raw material set by the combustion raw material regulator 5, or corresponds to the detection result of a flame detector such as a frame rod attached to the combustor 4. A threshold value may be set to a value that fluctuates.
[0042]
In the first to third embodiments, the power generation raw material and the combustion raw material have been described as the city gas 13A. However, the present invention is not limited to this, and the power generation raw material that can be sent to the fuel generator to generate the hydrogen-rich fuel gas. Further, it may be a combustion raw material, for example, another type of city gas mainly composed of hydrocarbons, LP gas, liquid fuel (kerosene, gasoline, methanol, dimethyl ether, etc.), and the power generation raw material and the combustion raw material may be different.
[0043]
In the first to third embodiments, the supply amount of the combustion raw material is compared with the threshold value. However, even if the output of the combustion raw material regulator 5 is compared with the threshold value, the combustor Since it can be judged that the amount of the combustion raw material supplied to 4 is smaller than the threshold value, it is obvious that the same effect can be obtained.
[0044]
【The invention's effect】
As is apparent from the above description, according to the configuration of the present invention, the temperature of the fuel generator can be quickly lowered, the temperature of the fuel generator can be easily controlled, and the fuel generator 2 can be controlled. Thus, the abnormally high temperature state can be prevented while maintaining the operating state, and a stable and highly reliable fuel cell power generator can be provided.
[Brief description of the drawings]
FIG. 1 is a block diagram of a fuel cell power generator according to a first embodiment of the present invention. FIG. 2 is a block diagram of a fuel cell power generator according to a second embodiment of the present invention. Fig. 4 is a block diagram of a fuel cell power generator according to a third embodiment. Fig. 4 is a block diagram of a conventional fuel cell power generator.
DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Fuel generator 3 Power generation raw material regulator 4 Combustor 5 Combustion raw material regulator 6 Combustion fan 7 Air supply amount regulator 8 Blower 9 Current detector 10 Residual hydrogen estimator 11 Air fuel ratio setting device 12 2nd air fuel ratio Setter 13 Air amount calculator 14 Temperature detector 15 Second power generation material regulator

Claims

A fuel cell body that generates power with fuel and an oxidant and discharges residual fuel gas containing hydrogen, a fuel generator that generates the fuel from power generation raw material and water, and burns the residual fuel gas and combustion raw material From the combustor for heating the fuel generator, the combustion raw material regulator for setting the amount of the combustion raw material supplied to the combustor, the air supplier for supplying air to the combustor, and the air supplier An air flow rate regulator that regulates the flow rate of the supplied air, and a fuel cell power generator that controls the temperature of the fuel generator by adjusting the amount of combustion feed supplied by the combustion feed regulator, If the amount of the combustion feed supplied to the combustor is less than a threshold that indirectly indicates that the hydrogen in the residual fuel gas is beginning to surplus , the air flow regulator is connected to the combustor. Supply more air than usual Fuel cell power plant characterized by so that regulation.

A fuel cell body that generates power with fuel and an oxidant and discharges residual fuel gas containing hydrogen, a fuel generator that generates the fuel from power generation raw material and water, and burns the residual fuel gas and combustion raw material A combustor for heating the fuel generator; a combustion raw material regulator for setting the amount of the combustion raw material supplied to the combustor; a temperature detector for detecting the temperature of the fuel generator; and the combustor. An air supply device that supplies air; and an air flow rate adjuster that adjusts a flow rate of air supplied from the air supply device, the supply amount of the combustion feedstock is adjusted by the combustion feedstock regulator, and the fuel generator A fuel cell power generator for controlling the temperature of the fuel cell, wherein the amount of the combustion raw material supplied to the combustor is smaller than a threshold value indirectly indicating that the hydrogen in the residual fuel gas starts to be surplus The air flow regulator The fuel cell power generator is characterized in that the flow rate of air supplied to the combustor is adjusted so that the temperature of the fuel generator detected by the temperature detector is maintained at a temperature necessary for generating fuel. .

A fuel cell body that generates power with fuel and an oxidant and discharges residual fuel gas containing hydrogen, a fuel generator that generates the fuel from power generation raw material and water, and burns the residual fuel gas and combustion raw material A combustor for heating the fuel generator; a combustion raw material regulator for setting the amount of the combustion raw material supplied to the combustor; a temperature detector for detecting the temperature of the fuel generator; and a flow rate of the water. A fuel amount generator that adjusts the amount of combustion feed supplied by the combustion feed regulator and controls the temperature of the fuel generator, the combustion being supplied to the combustor If the amount of feed is less than a threshold that indirectly indicates that more hydrogen in the residual fuel gas has begun , the water volume regulator is connected to the fuel generator detected by the temperature detector. Temperature needed to produce fuel Fuel cell power plant and adjusting the amount of water supplied to the fuel generator so as to keep the temperature.